What are the advantages of time recording machine in an office ?

    What are the advantages of time recording machine in an office ?


    Showing up for work punctually, at an official time, became expected behavior toward the end of the 19th century, as more and more people worked for others rather than for themselves. Not just the work force's punctuality was at issue. Cost accounting and analysis--recording and scrutinizing expenses for labor, materials and overhead--were getting more attention than ever before. Time was money.


    In the 1890s, timekeepers-- clerks who kept track of employees' hours in handwritten logs --found that machines were beginning to replace them, especially in workplaces with large numbers of employees. Thanks to the influence of the advocates of scientific management, nearly every industrial workplace had a time clock, after about 1910. So did many offices. By the early twentieth century the International Time Recording Company supplied an entire line of timekeeping devices, including master clocks, several types of time clocks, and time stamps. Founded in 1900, the firm continuously expanded its product line, underwent several reorganizations and name changes, and emerged in 1924 as the International Business Machine Corporation, familiar today as IBM.One of the firm's most popular products was the card punch time recorder, a clock that could furnish a daily or weekly record of up to 150 employees. Based on the 1888 patent of physician Alexander Dey, the dial time recorder was essentially a spring-driven clock with a cast-iron wheel affixed to its dial side. The rim of the wheel was perforated with numbered holes. As employees pressed a rotating pointer into the hole at their assigned number, the machine recorded the time on a preprinted sheet and rang a bell with each punch. A two-color ribbon printed all regular time in green and all tardiness, early departures, and overtime in red.This International digital card punch time recorder hung in a factory in the garment district of New York City.


   



    Time recording clock is a time recording machine used to record the lime of arrival and departure of an employee. The time is recorded on the card allotted to each employee of the organisation. The card is punched in this machine, which records the time of arrival and departure automatically. These machines are fitted with a clock to show the time. The advantages of the use of time recording machines are:


   



    (a) It records the actual time of arrival and departure.


   



    (b) It is not possible to manipulate the time in case of late arrival or early departure.


   



    It is necessary to keep proper record of time for each worker as it ensures discipline, increases morale and makes him punctual.


   



    This function of keeping proper record of time is looked after by the time-keeping department. In a small organisation, such a department may not exist at all since the time of coming and going can be easily regulated by the person in changes of operations in the factory or the office.


   



    Time keeping is a system of recording the time of arrival and departure of workers; it provides a record of total time spent by each worker engaged in the factory. On the basis of this record, wages are paid to the workers under time rate system.


   



    The regal contains the columns like name and identity no. of the worker, the department in which he is working, arrival and departure time. As soon as a worker enters into the preprint of the factory, the necessary entries in the attendance register are completed. If workers are literate; they are required to sign the attendance register.


   



    After the reports time workers are marked late or absent as the case may be. Similar entries are made the time of departure.


   



    This method is very simple and inexpensive. But in a large factory this meth may become inconvenient. Moreover, this method is liable for many undesirable’ practices on the part of the persons who record the attendance in collusion with sour workers. This method is suitable for small factories and out-doors workers.


   



    Under this method, each worker is allotted a metal disc or token bearing his identification. On each disc or token the name and number of the worker is engraved or painted. All the tokens 01; discs are hung on a board at the gate or at the entrance of the department.


   



    As soon as a worker reports for duty, he removes his disc and puts it in a box provided nearby. Immediately after the scheduled time of entry, the board is removed and a list is prepared for all such discs or tokens not collected and dropped into the box by the workers.


   



    The late-comers collect their discs and hand over the same personally to the time keeper. The list of late-comers is prepared separately. The discs not removed from the boards represent the absentee workers.


   



    This method is simple and economical. But it is not free from abuses. A worker may remove the disc of his fellow-worker to ensure his presence who is either late or absent.


    There is no certainty that the exact arrival time of the workers has been recorded. The time keeper marking the attendance may commit errors deliberately or through carelessness and this may create disputes. Time keeper may include the dummy or ghost workers in the muster roll that cannot be easily detected except by close supervision.


   



    2. Mechanical Methods


   



    Different mechanical devices have been designed for recording the exact time of the workers. These include:


   



    (a) Time Recording Clocks


   



    (b) analogue card punch time recorder


   



    (a) Time Recording Clocks


   



    This method has been developed to remove some of the difficulties faced in case of manual methods. Under this method, the attendance is marked by a time recording clock on a card. Every worker is allotted a time card usually for one week duration.


   



    These time cards are serially arranged in a tray at the gate of the factory. On arrival the worker picks up his card from the tray and inserts the same into the time recording clock which prints the exact arrival time at the space provided on the card against the particular day.


   



    This process is repeated when the worker leaves the factory after day’s work. Other particulars of time in respect of late arrival, lunch, and overtime are printed is red colour so as to distinguish these from normal period spent in the factory.


   



    This method is useful when the number of workers is fairly large. There are also no chances of disputes arising due to recording of time of workers as it is recorded by the clock and not by the time keeper.


   



    But there are chances that a worker may get his friend’s card from the tray and mark him present in time when he is actually late or absent. Any mechanical defect may adversely affect the working of time recording system.


   



    The dial time recorder is a machine which records the correct attendance time of the worker automatically. It has a dial around the clock with a number of hold (usually about 150), each of which bears a number corresponding to the identification number of the worker concerned.


   



    There is a radial arm at the centre of the dial. While a worker enters into the factory; he is required to press the radial arm after placing ill at the appropriate hole. The time recorder then automatically records the time on a roll of paper within the machine against the number of the worker.


   



    This machine can also! calculate the wages of the workers with greater accuracy and avoids much loss of time, I But a heavy capital investment is needed and hence only large organisations can use It is also necessary to have a close supervision on every worker to prevent fraud and I irregularities.


    Make employee scheduling and pay calculation easier with this fingerprint time attendance. A perfect choice for tracking hours in busy workplaces, this time stamp keeps accurate time within fractions of a second by automatically syncing with codes from the National Institute of Standards and Technology. This device automatically adjusts for Daylight Saving Time and ensures consistent accuracy during power failures using an internal battery backup. Featuring over 150 print configurations and 13 messages in four languages, this device makes it easy to print custom messages in two hour formats and a variety of font sizes. Compatible with a variety of forms and time cards, this flexible machine aligns any document perfectly with an internal LED and a window over the print area. This Acroprint time recorder informs users of the time and date with a large, bold display.


   



    Black/gray punch card time clock system for unlimited number of employees


    LCD display helps you keep track of time by showing the time and date in 24- or 12-hour format


    Durable construction and key lock help protect clock and settings from damage or tampering


    Employees use printable time cards


    Dimensions: 5.63"H x 6.45"W x 6.77"D


    Desk- or wall-mountable for flexible and convenient placement


    Battery backup protects data and settings during power outages


    Selectable language format: English, French, Portuguese, and Spanish


    2-year manufacturer limited warranty


    No resetting needed.The LCD backlight digital time punching machine synchronizes automatically with time codes transmitted by the National Institute of Standards and Technology, keeping it incredibly accurate. The internal battery backup keeps the clock on time, even during power outages.Flexible options.With over 150 possible print configurations and 13 preset messages in your choice of four languages, the ES700 easily supports a wide variety of time & attendance and document control applications. This time stamp accomodates virtually any time card, document or form, offering adjustable print font size, your choice of automatic, semi-automatic or manual print operation, and left or right hand print. The power supply is switchable from 120V to 240V.Easy to use.Cards and documents are a snap to align correctly, thanks to a handy window in the cover and a bright internal LED illuminating the document print area.

All About Knitted Hats

    All About Knitted Hats


    Quarantine has sparked plenty of new at-home hobbies. Maybe you picked up a paintbrush and tapped into your inner artist. Or, you might have transformed your kitchen into a bakery. For some, perfecting their knitting and crocheting skills even led to a business — which is why you're likely seeing the knit hat trend unexpectedly taking off on Instagram.


   



    For Delsy Gouw, founder of Brooklyn-based label Its Memorial day, crocheting started out as a fun activity. "[It] originally started as an online Depop vintage shop [in 2019] but when Covid hit, I wasn’t able to source any goods," she tells TZR. "I also lost my job and found myself with a lot of time on my hands." Gouw picked up the old hobby of hers and began making items for friends, and then her friends' friends were requesting pieces, too. She then began crafting knit hats because she believed the demand was there. "I started with bags but when I posted them so many of my friends and followers asked when or if I’d be open to making hats and taking customs for hats," Gouw tells TZR. While trends typically fade away and come back later on, Gouw hopes this style will stay long-term. "[I] can’t speak for knitting, but the way crochet is done is truly so intricate, unique, and is made to last," she explains. "Crochet can only be done by hand so I think there is something special about having an accessory that is unique and handmade." Fans of Gouw's emerging brand include influencers like Reese Blutstein, Jo Rosenthal, and Ella Emhoff.


   



    Who knows when the first person decided to put something over their head to keep it warm, but knitters know that knitted hats for women are some of the most fun and easy things to knit.


   



    When they’re worked in the round there is little in the way of shaping, except when you get to the crown.


   



    Most hats are worked from the bottom up, with stitches cast-on and worked in a snug stitch pattern such as ribbing, or in stockinette for a rolled bring hat, using a smaller size needle than is used for the head portion of the hat.


   



    In many hat patterns, the hat is worked straight for the desired length of the crown, then nearly all of the stitches are evenly decreased over the course of just a few rounds.


   



    The yarn is cut, the tail threaded through the remaining stitches, pulled tight, and fastened off to the inside of the hat.


   



    The hat can be topped with a pom pom, i-cord, tassel, or whatever embellishment strikes your fancy.


   



    A great book for learning to make hats is Ann Budd’s Handy Book of Patterns, from which some of the material on this page is excerpted. There are chapters on basic hats as well as the type of hats called “tams.”


   



    There are several types of hats, but the most popular knitted hats for men are beanie-type caps, tams (sometimes called “berets”), slouch hats, earflap hats, and tuques.


   



    Beanies: These hats can be super simple or dressed up with a lace or cable patterns. In cooler climates, they’re wonderful gifts for knitters to make.


   



    Tams/Berets: There are so many different stitch patterns to use in this style. Tams and berets can be plain stockinette or intricate Fair Isle. This style of hat is really flattering on just about every face shape, too.


   



    Earflap Hats: These hats are popular in cold climates. They’re great for keeping ears warm and they’re fun to knit. The knitters of Peru specialize in these hats, as shown in the photo at right.


   



    Often a knitted hats for children will have a finished size that is smaller than the average adult head. That’s because hats meant to fit closely at the brim need a bit of negative ease to help them fit snugly and keep them on the head.


   



    The amount of negative ease refers to the difference between the finished size of the object and the size of body part on which it will be worn. A hat that measures 19″ (48.5 cm) around and is worn on a 22″ (56 cm) head has 3″ (7.5 cm) of negative ease.


   



    A beret-type hat might have negative ease at the brim, but a few inches of positive ease in the body of the hat. The extra fabric is what creates its loose, flowing shape, while the tighter brim keeps it fitted to the head.


   



    Hats are a natural for circular knitting (or knitting in the round). This project for circular-knit adult hats offers three brim styles: hemmed, ribbed, and rolled stockinette. Whichever brim you choose, the directions call for shaping the top. Work this hat in plain stockinette stitch in a colorful or fashion yarn, or customize it by working the colorwork pattern included here. But don’t feel tied to those two options — use this hat as a canvas to express yourself.


   



    If you knit the hat on one 16-inch circular needle, you’ll need to switch to double-pointed needles (or one of the other methods) at some point during the crown decreases because the stitches will no longer reach comfortably around the needle. It is easiest to knit hats using the magic-loop method with one long circular needle.


   



    Choose a size


    Determine the circumference you want for the hat. Most hats should be knit with negative ease (. Measure around the widest part of the intended wearer’s head and subtract 1?2 to 1-1?2 inches from that measurement to calculate the hat circumference.


   



    A hemmed brim is not as stretchy as a rolled or ribbed brim, so it’s best not to include too much negative ease when using this hem.


   



    Choose yarn and determine the gauge


    Yarn for adult hats can run the gamut from practical to frivolous and fun. If you want a warm winter hat, for example, choose a yarn that is warm and durable, and knit it at a tighter gauge than recommended on the ball band. This results in a denser fabric that better retains heat. If, on the other hand, you are creating a fun accessory, you might choose a fashion yarn that adds a little flair. Because this hat is such a simple shape, it’s a great way to show off variegated or self-striping yarns.


   



    To keep cool but stay warm during winter, you can’t skimp on great outerwear or outfit-making boots. The same goes for cold-weather accessories too: Because for the majority of the season, coats, boots, and, in this case, winter hats do most of the talking when it comes to bundling up while keeping things stylish. In order to break free from your standard winter-outfit formulas—and to keep your looks from looking like, well, everybody else—consider accessorizing functionally and fashionably this season. Here, find four headwear trends not to be missed, and shop 24 of the best winter hats, inspired by the most stylish women on the streets, from New York to Paris.


   



    Buckets and Beyond


    After runway debuts at Fendi and Loewe, the winter-ready hand knitted hat took over the streets last February—and this season the ’90s trend has continued to gain momentum. From shaggy faux furs to fuzzy angoras, from shearling to sherpa styles, the winter bucket hat is one of the cutest and coziest accessories of the season.


   



    The ribbed-knit beanie has earned its place as a winter style staple for everyone from downtown urbanites to alpine skiers. New Yorkers might prefer sleek styles in a neutral color palette like black and speckled gray. Meanwhile, a pop of color would bring the perfect amount of joyous street-style-inspired Scandi chic to any drab winter look. And for those who wish to channel a bit of après-ski flair in their daily commute, look no further than one with a floppy, fluffy pom-pom.


   



    The trapper hat is no longer just for the rugged outdoorsman or Elmer Fudd. Not convinced? The trapper has been deemed stylish enough for even the Parisians—in fact a black faux-fur version was spotted on the streets topping off a geometric-print coat, leather pants, and blue ankle booties for the ultimate in warmth and style. Et voilà! Not to mention everyone from classic winter-weather brands to It labels are backing the trapper trend—Heurueh, Kule, and R13 to name just a few. You heard it here first: The trapper is the ultimate winter hat for women this season.


    On the tiny Peruvian island of Taquile, a man's worth isn't measured in his ability to hunt or fish, but in his ability to knit.


   



    Alejandro Flores Huatta was born on the 1,300-person island, which is located on the Peruvian side of Lake Titicaca, a three-hour boat ride from the nearest city of Puno. The 67-year-old learned how to knit the iconic chullo (a tall, floppy Andean hat) as a child, with his older brother and grandfather teaching him by using the thorns of a cactus as knitting needles.


   



    "Most of the people learn by looking, watching. Because I don't have a father, my older brother [and grandfather] taught me to knit. So by watching, I learned little by little," he said, speaking through a Quechua translator.


   



    Taquile is famous for its textiles and clothing, and while women weave and tend to the sheep that provide the wool, men are the ones who exclusively produce the island's knitting cap for baby. The chullos are seen as culturally significant, playing a key role in the island's social structure and allowing men to show their creativity while also displaying their marital status, dreams and aspirations – some men even use it to show their mood. It's a tradition that islanders are working hard to preserve.


   



    Residents were relatively cut off from the mainland until the 1950s, and the island's isolation has helped to keep its heritage and way of life intact. Locals abide by the Inca code of "Ama sua, ama llulla, ama qhilla", (Quechua for, "Do not steal, do not lie, do not be lazy&quot. Taquileans are farmers traditionally; the six island communities take turns to rotate crops of potato, corn, beans and barley in terraces on the mountainsides. They raise sheep, guinea pigs, chickens and pigs on the land and fish in the lake. Tourism kicked off in the 1970s, giving locals a source of income with tens of thousands of visitors drawn to the island annually to tour the villages and surrounding lake. Visitors typically stay with locals in humble, family-run accommodations; lend a hand-harvesting crops; try local specialties like fried trout and potatoes with rice, beans and mint tea; and purchase the island's famous handmade textiles.


   



    Hats reveal men's marital status, dreams and aspirations


    In 2005, Taquile's textile art was deemed so valuable that Unesco deemed it an Intangible Cultural Heritage of Humanity. Alejandro is one of the seven men on the island recognised as a Master of Textiles, along with the island's president, Juan Quispe Huatta.


   



    The tradition has been around for the better part of 500 years, with roots in the ancient civilisations of the Inca, Pukara and Colla peoples. The Inca in particular, used their headdresses in a similar way to the Taquilean chullo, to display the specific insignia of their particular province – but that’s where the similarities end. The Taquilean chullo and the Inca headdresses look vastly different. The elders of the island tell of the chullo design arriving with the Spanish conquest in 1535, and Alejandro's grandfather passed on stories of the early conquerors wearing similar hats that were white with ear covers, "but not the same patterns or symbols," Alejandro said.

Effective cleaning of rust stained marble

    Effective cleaning of rust stained marble


    Calcareous materials, like marble used in

connection with cultural heritage objects such as statues and pedestals, or as wall facings on buildings, often show a

brownish staining owing to contact with iron metal or iron-containing minerals in the stone. The discolouration alters the

appearance of the stone, which is undesirable from an aesthetic point of view. Despite rust staining being a conspicuous

phenomenon and numerous works that have dealt with the problem of removing rust stains, a simple and non-toxic method has so

far been missing. This paper describes a highly efficient method for cleaning rust stains from marble by introducing the

chelating amino acid cysteine in a Laponite poultice in combination with the strong reducing agent sodium dithionite.




    Results


    Cleaning experiments were performed on artificially discoloured samples of various types of Carrara Bianco marble and on

naturally rust stained marble. To begin with, solutions of cysteine in combination with sodium dithionite and ammonium

carbonate were tested by immersion of samples into the different solutions. Secondly, solutions of cysteine and sodium

dithionite with and without buffering were used in a poultice consisting of Laponite? RD, Arbocel? BC1000 and CMC. The

poultice was applied on three different marble types: Carrara Fabricotti, Carrara Vagli and Carrara La Piana. Thirdly, the

optimized method was tested on original rust stained material of luxury marble, which has been used as wall facing, and finally in situ in Copenhagen on a larger

area of The Marble Church showing rust stains due to pyrite oxidation. The cleaning results were evaluated by visual

observations, cross sections, and etching of the surface by testing on high gloss marble.




    Conclusion


    Cleaning of iron-discoloured marble surfaces has been investigated and a new method for removal of rust stained marble

has been developed. A solution of 0.1 M cysteine and 0.1 M sodium dithionite in a poultice consisting of Laponite?

RD/Arbocel? BC1000/CMC = 10:10:1 has shown to be a fast, simple, cheap, and non-toxic, do-it-yourself method.



    Since ancient times, white marble has been used as a popular material for sculptural artefacts such as statues, busts,

and friezes as well as an architectural building material with numerous applications from flooring, wall facings, and

pedestals, to columns and fountains. Although marble is a relatively stable material, the desired white surface is

unfortunately prone to tarnishing when used in outdoor environments [1]. One of the major sources of tarnishing is iron. In

addition to the oxidation of internal iron compounds present in stone like pyrite (FeS2) and siderite (FeCO3) [1, 2], contact

with iron-rich ground water when Full

Body Marble is used in, for example, garden fountains, results in severe and unsightly discolouration [3]. Another cause

is the proximity to iron metal, which is oxidized by air in the presence of rain. The solubilized ions are then transported

by rain onto the marble surface, resulting in rust formation [4].




    The detailed mechanism for rust formation is highly complex; depending on the pH value, different species, all

characterized by a brownish colour, are formed. The atmospheric corrosion of iron, regardless of the pH value of the reaction

may, however, be summarized by the overall stoichiometric reaction (1) where the product FeOOH represents the generic formula

for rust [5].



    The general name rust consists of a variety of iron(III) oxyhydroxides or hydrated oxides of high stability and low

solubility. The actual species formed depend as mentioned on the pH value and the presence of different anions [6–8]. The

thermodynamic parameters and solubility products have been estimated for many of the rust species, such as ferrihydrite and

α-, β- and γ-FeOOH (goethite, akaganeite and lepidocrocite). These investigations have shown that goethite defines a

thermodynamic minimum of the rust system [7, 9] and the solubility product of goethite (Ksp = 10?41) is the lowest among the

different rust species [7]. This means, from a thermodynamic point of view, that rust can be examined as goethite, and thus

the cleaning of rust can be considered as removal of goethite.



    Rust discolouration of marble is characterized by areas or stains having an orange to brownish colour, which alters the

appearance of the stone. From an aesthetic point of view, the discolouration is undesirable and stone conservators and

conservation scientists have therefore worked for several decades with various cleaning methods in attempts to remove rust

stains from marble and calcareous stone materials [3, 10–12].




    Due to the nature of the discoloration and the possibility of damaging the stone, the stain can only be removed by

chemical cleaning. The current method for rust cleaning involves application of different ligands and reducing agents mixed

in a poultice and placed onto the stone surface. One of the ligands most widely used is the citrate ion [10, 11, 13], though

salts of other carboxylic acids, such as oxalic and tartaric acid, have also been used [10]. Other methods involve the use of

fluoride [10] or EDTA [12]. A relatively new method is the use of the hexadentate ligand tpen, which, in contrast to EDTA,

has a high affinity towards iron and a low affinity towards calcium [3]. This ligand has shown excellent results when tested

on a discoloured marble fountain, however this method is rather expensive. The ligands are used either alone or in

combination with reducing agents like thiosulfate, dithionite or polythiophene [3, 10]. Thioglycolic acid and ammonium

thioglycolate have been applied in several conservation treatments of calcareous stone [12]. Thioglycolate is presumably the

most efficient ligand for cleaning rust stained marble [12, 13]. However, thioglycolic acid is a toxic chemical, and is thus

difficult to acquire for private stone conservators without access to a laboratory. In addition to this, a slightly violet

colour may appear on the marble when cleaning with thioglycolic acid, which demands a second cleaning [12].




    In this study, we have aimed to investigate and develop a new method for rust cleaning of simm marble. The focus has been on the use of

cheap and commercially available chemicals. Another target was reduction of Fe(III) to Fe(II) while cleaning. Efficient

removal of a slightly soluble material requires a ligand having an overall stability constant comparable to the reciprocal

value of the solubility product in order to achieve a favourable equilibrium constant. Based on the solubility product of

goethite, efficient removal of rust in Fe(III) stage requires a ligand having a stability constant approaching 1041, whereas

removal of Fe(OH)2 only requires a stability constant of 1014. Additionally, the ligand should possess low affinity towards

Ca(II) to prevent dissolution of calcite.




    Introducing new chemistry for rust cleaning


    In the search for an efficient method for rust cleaning, the focus has been both on a ligand showing strong complex

formation with iron and weak binding to the major constituent ions in marble i.e. Ca(II) and Mg(II), as well as on the

identification of a fast reducing agent able to reduce Fe(III) to Fe(II). Among the reducing chemicals, sodium dithionite

(SD), Na2S2O4, has been successfully used in combination with different ligands as a dissolving agent for goethite in soil

analyses [14, 15] and for removal of rust from paper [16]. Furthermore, the use of dithionite in conservation science in

general is well described [17].





    The standard reduction potential, e°, of dithionite in the basic solution given in Eq. (2) has been determined to ?1.12

V (vs. NHE) [15, 17] and is thereby one of the strongest reducing agents among the simple, cheap, commercial reagents. The

reducing power decreases with lower pH values and using pKa2 = 7 for hydrogen sulphite the potential can be calculated to e°

′ = ?0.29 V at pH = 7.




    In aqueous solution dithionite partly dissociates, forming the highly reactive monomeric sulphur dioxide radical anion

with the dissociation equilibrium constant K = 10?9 [18].





    Even though the amount of the radical anion is relatively small and can be estimated to 10?5 M in a 0.1 M dithionite

solution, the anion has shown to be the dominant reducing species in the reduction and dissolution of iron oxides [14, 15].

From biochemical experiments, the standard reduction potential of the radical anion has been determined to ?1.39 V (vs. NHE)

in basic solution [18, 19], giving a calculated value e°′ = ?0.56 V at pH = 7 in accordance with experimentally determined

values [18].




    The reduction potential for reduction and dissolution of synthetic goethite has been calculated to e°′ = ?0.14 V (vs.

NHE) at pH = 7 [20]. Using this value and either dithionite or the sulfur dioxide radical anion in the reduction and

dissolution of goethite to Fe(II), the reactions can be written as in Eqs. (5), (6) with the electrochemical potentials of E

°′ = +0.15 V or E°′ = +0.42 V.



    Both reactions are spontaneous processes with relatively large equilibrium constants, which can be calculated to K = 105

or K = 107, respectively. From a thermodynamic point of view, dissolution of rust could be achieved by SD solutions only.

However, the presence of a ligand for removal of the Fe(II) ions is preferable in order to avoid re-precipitation caused by

oxidation from oxygen.


   



    In search of a ligand useful for rust removal, a sulphide-containing species similar to thioglycolate were examined. The

amino acid cysteine (cys), commonly found in natural proteins as the L-isomer, is commercially available and affordable.

Cysteine forms complexes with Fe(III) and Fe(II) with high stability constants and only very weak complexes with Ca(II) and

Mg(II) [21]. At the same time cysteine reacts as a reducing agent in the iron(III)-cysteine complexes with formation of

colourless Fe(II)-cysteine complexes [22]. The intense violet colour known for Fe(III) complexes with ligands containing

thiol groups like cys and thioglycolate [12, 22] may therefore be avoided. In addition to this, cys is also able to perform

reductive dissolution of iron(III) oxyhydroxides, thereby independently having a solubilizing effect of rust [23].


   



    Table 1 shows the stability constants of the marble constituents Ca(II), Mg(II), Fe(II) and Fe(III), with the commonly used ligands for rust cleaning

i.e. citrate [24], oxalate [24], tartrate [24], edta [25], tpen [26, 27] and thioglycolate [24, 28], together with cys [21,

28]. The solubility products of CaCO3 [29], MgCO3 [29], Fe(OH)2 [29], and FeOOH [7] are also given. As seen from the

constants, only edta shows affinity towards Mg(II) and Ca(II) in an order resulting in serious dissolution of MgCO3 and

CaCO3, whereas the remaining ligands display relatively weak binding constants, causing little dissolution of marble itself.

The stability constants of cys are similar to the values of thioglycolate, and cys possess very high affinity towards iron

(III), which is even higher than for edta. Towards iron(II) the overall stability constant is of an order of magnitude close

to the value for tpen, thus making cys an ideal candidate for cleaning of rust stained marble.


   



    Reduction of Fe(III) to Fe(II) by cys is accomplished by oxidation to cystine, which is insoluble in water, causing

unwanted precipitation. However, the presence of SD together with cys prevents precipitation of cystine due to the ability of

dithionite to re-reduce cystine formed. The reduction potential of cys is estimated to approximately e′ = ?0.25 V at pH = 7

[22] which is higher than the potential of dithionite. In Fig. 1, the reduction reaction from cystine to cys (zwitterion

form) is shown together with the acid dissociation of the thiol group, forming a cysteinate species. This anion may react as

a bidentate ligand towards metal ions via the sulphur and oxygen donor atoms [22], but other coordination involving O, N and

O, N, S donor atoms are also possible. The iron-cysteinate complexes are complicated and not straightforward due to redox

reactions similar to those observed for the iron-thioglycolate system [22, 28, 30–32].


   



    The pKa values of three functional groups i.e. carboxylic, thiol and protonated amino group are 1.88, 8.15 and 10.29,

respectively [23]. Using the values of the first two pKa constants, pH in solution of the cys zwitterion can be estimated to

pH 5. In general this pH value is too low for cleaning marble, due to acid dissolution of CaCO3 [12, 13]. The pH value can be

adjusted by the addition of a base such as ammonia (NH3) or ammonia carbonate ((NH4)2CO3), and in some cases when the

cleaning mixture is used in a poultice, the poultice itself can act as a buffering agent. Laponite, for example, releases OH?

below its point of zero charge, which is obtained around pH = 11 and an aqueous suspension of Laponite is alkaline [33]

(measurement shows pH = 9.3). Since the dissolution of goethite consumes H+ (Eqs. 5 and 6), the pH is also raised during the

reaction. Considering that the oxidation of iron(II) and cys is eased with increasing pH favouring precipitation of both

iron(III) oxyhydroxides and cystine, a reaction value around pH = 7 may be preferred, although pH = 9?10 is desired with

respect to the solubility of calcite [3, 12].


   



    Introducing a new poultice for rust cleaning


    The chemicals used for cleaning of stained marble are commonly applied in a poultice and a wide range of poultice

material has been tested and applied in stone conservation. Clay materials, such as bentonite, attapulgite and sepiolite, are

widely used either alone or in combination with cellulose fibres [4, 10, 34]. Other methods use cellulose fibres alone [35,

36], MC (methyl cellulose) [37], CMC (carboxymethyl cellulose) [38], cotton pads [10, 38], and gels like glycerine [10], agar

[39], agarose [40], or xanthan gum [3]. One of the newer materials used for poultices is the synthetic magnesium silicate

clay Laponite? RD [41–44]. When dispersed in water, Laponite produces a colourless thixotropic gel that is easy to apply on

specific areas and on vertical surfaces. The high purity of Laponite and thereby the absence of natural iron impurities means

that discolouration of the marble surface from the poultices itself is avoided. In this study, Laponite? RD is mixed with

cellulose fibres (Arbocel? BC1000) with dimensions of 700 × 20 μm (lenght and thickness) in order to increase the porosity,

the absorbing properties and the water retention of the poultice. In addition to this, a small amount of sodium CMC

(carboxymethyl cellulose, sodium salt) was also added. This resulted in better mechanical properties, increasing both the

adherence and the cohesion of the poultice, making it easy to apply and remove in large pieces without crumbling. Another

advantage of this poultice composition was its shrinkage properties: when drying it shrank practically only in the direction

of thickness, leaving the area dimension intact. Hence a uniform cleaning from the centre to the edge of the poultice was

obtained.


   



    Three different types of white Carrara marble (Carrara Bianco): Carrara Fabricotti, Carrara Vagli and Carrara La Piana

from the Carrara quarry in Italy were received. Prior to the study and the artificial discolouration, the marble samples were

characterised by the European Standards for water absorption, DS/EN 13755:2008 and water absorption coefficient by

capillarity, DS/EN 1925:1999. Original samples of naturally rust stained Greenlandic marble from 1937 were retrieved from the

government building of The Public Guardian in Copenhagen, Denmark in connection with restoration of the building. The marble

plates were used as wall facing and, when dismounted, a heavy iron discolouration was present on the backside of the plates.

A high gloss polished marble of the type Carrara Bianco, Lorano was used for etching experiments.

Recommended Lighting Kits for Photography

    Recommended Lighting Kits for Photography


    If you follow some basic lighting principles, you can get impressive results from even the cheapest of motorcycle light combo kit. This is great news for businesses with smaller budgets or folks just starting out with video. As an experiment, we went to Home Depot and built a lighting kit with clothespins, clip lights, and LED bulbs.


   



    While this is not the be-all, end-all lighting kit, it is an attainable and repeatable setup that will keep people on camera looking sharp and well-lit.


   



    Please allow us to introduce Wistia’s “Down and Dirty DIY Lighting Kit” – all for under $100.


   



    Our trip to Home Depot


    You can build almost an entire DIY lighting kit with items you can find at any hardware store. Places like Home Depot, Lowes, and ACE should readily stock everything you’ll need.


   



    The effectiveness of this motorcycle fog led light kit hinges on good quality bulbs. Look for daylight balanced bulbs with a high CRI (color rendering index). This will help to produce the highest quality and most flattering light possible. Also, make sure you purchase bulbs that are dimmable. We’ll explain more about this later.


   



    Lights, lights, lights, lights, and more lights. You’ll find them all here at B&H and, even if you are a professional photographer with decades of experience, the sheer number of lighting options today can drive you mad. It drives us mad. You might be thinking, “Where do I even start and how do I find the great auxiliary light combo kit?” Well, today’s your lucky day, because the place to start is right here, with this list of 14 recommended lighting kits—seven flashes and seven continuous—that will help photographers get the job done.


   



    Flash Lighting


    We are going to start with a staple of photography: flash. Also known as strobes, these are awesome for photographers because they provide plenty of power, can help freeze motion, and come in nearly any size. Also, the various sync methods—and the fact that now many have built-in radio receivers, make multi-light setups easy. There are plenty of variables to guide your decision, including recycle time, battery versus AC power, accessories, wireless system, and power, so here’s a healthy helping of different types to peruse.


   



    In the very beginning of your lighting journey, you will want something versatile and with the ability to mount directly on your camera. Something like the Bolt VB-11 Bare-Bulb Flash. Being bare bulb means that it can provide a similar look to classic strobes with 360° coverage and high power at 180Ws. It benefits greatly from accessories to modify the light, all of which are included in the Flash and Accessory Kit. Another advantage is the ease with which you can set it up on a light stand or slide it into the hot shoe of your camera, depending on how you want to use it that day. Want something easier to start out with? Go with the Bolt VD-410 Manual Flash and read up about speedlights.


   



    Need something that’s portable, like a speedlight? How about a bare-bulb design that gives the 360 degrees of coverage? Get both with the Godox AD200Pro TTL Pocket Flash Kit. It has the basic form of a speedlight, though without the bounce functions, and has the ability to swap the head from a standard rectangular speedlight to a bare-bulb flash. It’s good and affordable with an excellent 200Ws of power that should be ample, and it runs on a rechargeable Li-ion battery pack that’s good for 500 full-power flashes on a single charge. It also features a built-in X Wireless System Receiver so you can use optional X Series TTL Transmitters to control and trigger the flash remotely. Adding this also enables high-speed sync via TTL. It’s an awesome and versatile lighting choice.


   



    Among Profoto’s latest releases as they push forward with their off-camera flash, or OCF, range is the stellar B10. Available in a two-light kit complete with backpack, the ultra-compact light is battery powered for use nearly anywhere you can stick it. The B10 is rated to 250Ws and has a 10-stop power range. Tack on a 0.05-22 second recycle time, freeze mode with a 1/50,000-second T0.5 flash duration, AirTTL support, and you have a seriously good flash to work with. Oh yeah, it also has LED modeling with with adjustable color temperature and CRI of up to 96 for video shooting on the side. All you need to complete the setup are any of Profoto’s highly regarded OCF Light Shaping Tools and a Profoto Connect for wireless TTL.


   



    A more conventional dirt bike light combo kit comes from the well-known and reliable Elinchrom. By conventional I mean the D-Lite RX 4/4 Softbox To Go Kit is close to what many picture when they think of advanced LED light kit—a couple of monolights with stands and softboxes. These strobes are no slouch, with each of the two heads including offering 400Ws of power. They run on standard AC power and can recycle in just 0.35-1.6 seconds, depending on power. Also, the D-Lite RX 4 has an EL-Skyport Receiver built in, so that you can trigger the camera remotely—easily—via the included EL-Skyport Transmitter Plus. Completing the kit are stands, an octagonal softbox, and a square softbox. Everything you need.


   



    When you hear the name of some brands, you just know you are getting a solid product. In lighting, one such brand is Broncolor, and one of its more recent releases is the Siros L 800Ws Barry-Powered Monolight, which we recommend in the 2-Light Outdoor Kit 2. These are among the most powerful battery-powered strobes, with a rating of 800Ws and benefits from Enhanced Color Temperature Control that ensures the ultimate in consistent color with repeated shots. This is something that Broncolor is known for and something that makes its lights so appealing to professionals. However, if you need some extra speed, there is a mode that will forgo these protections to provide faster recycle times and shorter flash durations, up to a minimum of 1/18,000-second. Optional RES2.2 Transmitters open the door for Broncolor HS, enabling sync speeds at up to 1/8000-second with supported systems. And, you can control multiple lights from your tablet or smartphone using the bronControl app.


   



    Regarding equipment for the rest of us, Dynalite has made the solid Baja A6-600 Monolight 2-Light Kit. This more affordable system can be very enticing, partially because it offers an impressive 600Ws output, which is more powerful than many of its competitors. These are AC-powered monolights, but the added power and 300W modeling light should be appealing for many studio shooters. Also, it comes with a wireless receiver that can work at distances of up to 590' when used with an optional transmitter. The transmitter also unlocks High Speed Sync with Canon or Nikon cameras. It is very much a traditional monolight, but it is a good one and a quite affordable kit, too.


   



    Speedlights and monolights changed the way photographers worked with lights by making them more portable and user-friendly. For the ultimate in performance, it is tough to beat your standard power pack, and the Profoto Pro-10 2400 AirTTL is among the best you can get today. Two outlets, a max of 2400Ws, a built-in Air receiver with TTL support, flash durations that can be as short as 1/80,000(!) second, and recycle times of just 0.02-0.7 seconds make this pack an absolute monster if you need the best of the best. There aren’t any pre-built kits, considering the super-pro nature of the Pro-10, so build your own by adding a couple of ProHead Plus Flash Heads to your bag.


   



    These days, many photographers are spending a healthy portion of their time working with video. Unfortunately, all those awesome flashes and strobes we just talked about can’t do both, since you need a continuous light to work with motion. While, yes, some strobes are packing LEDs that can serve as your video source—the recent Profoto B10 Plus comes to mind—it will be tough to beat dedicated tools such as the ones below.


   



    Relative newcomer Luxli has been killing it lately, and one of its latest is the awesome on-camera option that is the Viola2 5" On-Camera RGBAW LED Light. Its small size and outstanding color controls make it exceptionally versatile. For standard white adjustment there is a variable 3000-10000K temperature range, while the RGBAW nature of the fixture enables complete color tuning, including the ability to set 150 digital gel filters and 10 different special effects. This is ideal for a portable, on-camera light because it eliminates the need for other accessories in your bag. One other thing to consider is this kit with a softbox and diffusion filter. Additionally, it’s part of the Orchestra series, which can be controlled via a mobile app on your smartphone and work in sync with any other members of the band.


   



    Litepanels was one of the first major brands on the scene when LEDs first began to make inroads into photographic and cinematic lighting. It all had to do with the now-ubiquitous 1 x 1' LED panel, now having been updated to the Astra Bi-Color LED Panel. By using an array of high-quality LEDs, Litepanels was able to create a fixture that was lightweight, powerful, and could produce a soft output—all beneficial qualities when considering lights for photography. They could even run on batteries if you needed to use one on the go, and are practically silent. The shape is now classic, and if you want to pick up more than one, Litepanels has numerous Astra Traveler LED Panel Kits available.


   



    Hot lights made Lowel popular for decades. Now, the company is taking a good shot at the LED world by bringing out a new version of one of its most popular lights ever. The TotaLED Daylight LED Light is this reimagining, though it makes sure to maintain similar features to its predecessor. This includes an equivalent output to that of a 750W tungsten bulb, a beam angle of ~65° that can be expanded to 100° via the included diffuser, built-in barndoors, and more. Where this one differs is in its native 5600K color temperature, quite cool operation—no need for gloves with LEDs—and the ability to run on batteries, as well as AC power. If you want, there are two-light and three-light kits ready for purchase.


   



    Go beyond the panel with the Aputure Light Storm LS C120D II LED Light Kit. Using a chip-on-board (COB) LED, it effectively creates a single-point light source, which is more akin to classic tungsten fixtures with a single bulb. No worries about multiple shadows here, and the LS C120D II is exceptionally powerful with the equivalence of a 1000W hot light, while consuming just 180W of power. It also has DMX control, a redesigned handbrake-locking yoke, and can accept all types of Bowens S-mount accessories natively, including Aputure’s popular Light Dome II. Photographers on the go will appreciate the ability to run on either V-mount or Gold-mount batteries. You can pick it up by itself, or in two-light and three-light kits.


   



    Making the list as a personal favorite is the Light & Motion Stella Wedding Photographer Kit. The reason I like them so much that they were included here is that the company is one of very few that makes highly capable lights that are completely waterproof. They really mean waterproof, too. The Stella Pro 5000 and Stella 2000 in this kit are ready to go diving with ratings that make them usable down to 328' underwater. Tough lights can survive some of your crazier ideas and the Light & Motion ones are perfect for it. Both are battery powered and feature a COB LED with excellent, high CRI output that makes them a solid option for photographers working on location. They are also great, compact lights, and the Stella 500 can accept an optional Profoto Adapter to use your more conventional modifiers on it.


   



    The thing about LEDs is that they can be used in ways you never would’ve imagined. One such light that follows through on this is the Westcott Flex Bi-Color LED Mat Cine Set. It’s a completely flexible LED panel measuring 1 x 1', and there are plenty of other sizes available. Why would you want a flexible light? I would counter with a, “Why wouldn’t you want a flexible light?” It can be used on a stand just like your standard panels, yet, when the moment requires it, you can use it in very niche ways. It’s light enough to be taped up to a wall and thin enough to stay out of the shot. You can tuck it down into a case and fold it up so the light is directed a specific way. And that just touches the surface, I’m sure plenty of more imaginative photographers will find even more exciting ways to use it.


   



    LEDs are dominant, though we shouldn’t forget about classic tungsten, HMI, and fluorescent lighting. I’d like to draw your attention to one in particular: the Kino Flo 4Bank 4' Gaffer 2-Light Kit. Essentially the name to know when it comes to fluorescent lighting, Kino Flo’s lights are long revered in the industry for their soft, flicker-free output. Using True Match Fluorescent Lamps, the 4Bank can create a large, soft, and daylight-balanced fixture that has the equivalent output of a 1000W soft light with a fraction of the draw. The separated ballast can be located in an easy-to-access position, as well, while the fixtures’ flexible barndoors provide a simple way to control the light. These are great fixtures, and this kit gives you everything you need except the lamps.

Understanding Pipe Fittings

    Understanding Pipe Fittings


    Pipe fittings are components used to join pipe sections together with other fluid control products like valves and pumps to create pipelines. The common connotation for the term fittings is associated with the ones used for metal and plastic pipes which carry fluids. There are also other forms of malleable iron pipe fitting that can be used to connect pipes for handrails and other architectural elements, where providing a leak-proof connection is not a requirement. Pipe fittings may be welded or threaded, mechanically joined, or chemically adhered, to name the most common mechanisms, depending on the material of the pipe.


   



    There is some inconsistency in terminology surrounding the terms pipe, tube, and tubing. Therefore, the term Carbon Steel Pipe Fitting will sometimes be mentioned in the context of tubing as well as pipe. While similar in shape to tube fittings, pipe fittings are seldom joined by methods such as soldering. Some methods overlap, such as the use of compression fittings, but where these are commonplace for connecting tubes or tubing, their use in pipe connections is rarer. It suffices to say that while there are general distinctions, the common usage of terms can differ from supplier-to-supplier, although they represent the same items.


   



    In this article, the concentration will be on discussing typical fittings and connection methods associated with rigid pipe and piping, with a limited presentation of the fittings that are associated with flexible tubes, tubing, or hose.


   



    To learn more about the varieties of pipe, consult our related guide to pipe and piping.


   



    Pipe Fittings Explained: Fitting Materials and Manufacturing Processes


    Cast and malleable iron


    Fittings for cast iron pipe fall under hubless and bell-and-spigot styles. Hubless designs rely on elastomeric couplers that are secured to the outer diameters of the pipe or fitting by clamps, usually a stainless steel band clamp that compresses the elastomeric material and forms a seal. These hubless or no hub designs are sometimes referred to as rubber pipe couplings or rubber plumbing couplings and are especially popular for transitioning from one material to another—from copper to cast iron, for instance. Bell-and-spigot, or sometimes, hub-and-spigot, fittings are joined today primarily with elastomeric gaskets that fit inside the bell and accommodate the insertion of the plain pipe end or fitting. Older systems before the 1950s were caulked using a combination of molten lead and a fibrous material such as oakum. Cast iron pipe is sometimes joined with bolted flanges, or in some cases, mechanical compression connections. Flanged joints employed in underground applications can subject the pipe to settlement stresses unless the pipe is adequately supported.


   



    While there are both malleable iron pipe fittings and ductile iron pipe fittings available, the improved mechanical properties and lower cost of ductile iron is causing a shift towards greater use of that material.


   



    Fittings for steel (aka, “black pipe”) and galvanized pipe as found in residential and commercial plumbing work are generally cast and referred to as “malleable iron fittings." They can be galvanized. Although standards list threaded fittings up to fairly large diameters, these generally are not used today as the threading of large-diameter pipe is considered needlessly difficult.


   



    Steel and steel alloys


    Galvanized malleable iron pipe fittings are often extruded or drawn over a mandrel from welded or seamless pipe. In smaller sizes they are often threaded to match threads on the ends of pipe. As sizes and pressures increase, they are often welded in place by either butt-weld or socket-weld methods. Socket-weld fittings, usually forged, are restricted to smaller pipe diameters (up to NPS 4, but usually NPS 2 or smaller) and are available in 3000, 6000, and 9000 class pressure ratings, corresponding to Schedule 40, 80, and 160 pipe. Socket fittings are welded into place with fillet welds, which makes them weaker than butt- welded fittings, but still preferable to threaded fittings for high-end work. The need for an expansion gap in the fitting precludes their use in high-pressure food applications.


   



    Flanges are also used, with the resulting flanged sections of pipe connected via bolts. The use of flanges makes breaking the pipeline feasible so as to enable replacement of valves, etc. Most pipeline equipment such as pumps and compressors are also connected via flanges for this same reason.


   



    Flange fittings are available in a handful of styles, rated by pressure and temperature. These styles include lapped, weld neck, socket weld, ring-type joint, screwed, and slip-on. The threaded flange is suitable only for low- to medium-pressure applications. The other various welded-on flanges permit higher pressures to be used. Lapped flanges are often used where disconnections will be frequent as the flange can spin freely, simplifying bolt-hole alignment. A special case is the so-called blind flange, which is used to seal the end of a pipeline but allow connection to another pipe or piece of equipment later.


   



    Flanges can incorporate several different methods to seal adjoining faces, including O-rings, seal rings, and gaskets. Seal rings provide an especially tight joint and for the same bolt stress applied to a flat-face gasket, can resist a higher pressure.


   



    Primarily, three standards govern pipe flanges. ASME 16.5 defines the ANSI flange, the most commonly-used flange. ASME B16.47 covers two series, A and B, which represent large diameter applications. Series A flanges are heavier and thicker than Series B for the same pressure and size. Series B flanges are normally selected for refurbishment work. ASME B16.1 defines the AWWS flange, but it is only for flanges used in potable-water service at atmospheric temperatures. Then, there is the so-called Industry Standard flange which is not defined by a governing body but instead reflects historical practice. The dimensions for these flanges are covered by ASME B16.1, the standard for 25, 125, and 250 class cast-iron-pipe flange and flange fittings.


   



    Stainless steel pipe fittings can be used for sanitary applications such as food and dairy processing, and are commonly fitted with quick-connect clamps to enable dismantling of the line for internal cleaning. The flanges for these clamping systems are available as weld-on entities or in many instances available as wyes, tees, etc. with the flange integral to the fitting.


   



    Metal pipes sections may also be joined and built up as pipelines using pipe couplings and other standard black malleable iron pipe fitting such as metal pipe end caps or 180-degree pipe elbows.


   



    Nonferrous


    Aluminum fittings are typically cast. They are available in all the same forms or shapes as steel fittings. Aluminum threaded fittings such as caps or nipples are available, as are fittings that feature a combination of threaded and butt weld connection styles. Socket weld options also exist. Welding of aluminum fittings usually requires a MIG or TIG process.


   



    Aluminum pipe is also a popular choice for use in creating handrails, and a host of fittings for structural applications are available, both weldable and slip on/clamp-on varieties.


   



    Red brass fittings such as brass pipe nipples are available corresponding to pipe diameters, and these are often assembled by soldering or brazing.


   



    Concrete


    Concrete pipe fittings are available in a variety of styles suitable to their application in large civil projects such as storm-water control. Aside from the typical wye connections, specialized fittings include utility hole portals and various styles of vaults. Typical connections use shouldered ends on the fittings which mate with counterparts on the receiving pipes. A rubber gasket provides for a leakproof joint.


   



    Plastics


    Plastic pipe fittings are available in both socket weld (sometimes called solvent weld) and threaded styles, with the former the most common. Socket weld fittings are designed to be welded in place chemically, thereby making installation quick and straightforward to complete. Plastic pipes are usually dry fitted, then marked, as the solvent used to connect them is especially fast-acting. Couplings are typically used to connect and join straight lengths of pipe together.


   



    Fittings are available in standard shapes and styles and with the dimensional size ranges of material common to plastic pipe, including PVC, CPVC, PE, PEX, PP, and ABS.


   



    Common PVC pipe fittings include reducers, elbows, caps, tees, wyes, couplings, unions, and crosses, to name a few. The standard cross-sectional profile for most PVC pipe or tubing fittings is circular, but there are other profile shapes available, such as square PVC fittings. However, these alternative fitting profiles are usually associated with PVC pipe that is designated for structural use, such as fences, railings, or furniture grade use, and are not associated with PVC pipe that is fluid handling applications. Besides PVC, other materials may be used for structural fittings, one example being galvanized pipe railing fittings.


   



    Other PVC fittings include barbed insert designs, which are intended to be used with tubing and are pressed into the tubing and secured with band clamps.


   



    CPCV pipe fittings, as well as ABS pipe fittings (Acrylonitrile Butadiene Styrene), also are usually joined with fittings that are solvent welded. Suitable conversion adapters for changing material types, such as from CPVC to brass, are also commonly available.


   



    In some applications using plastic pipe, such as in plumbing for sink drains, certain pipe fixtures such as p-traps may be joined with a threaded connection using nylon washers and a retaining or locking nut. This feature facilitates easy disassembly to clear clogs.


   



    Polyethylene pipe fittings and polypropylene Galavanized carbon steel pipe fitting are usually available with both threaded style or barbed style connections, and socket weld or fused options being also available. Similarly, PDVF pipe fittings also are produced with socket or threaded connections.


   



    Where an air or watertight seal is needed, nylon pipe fittings may be employed and can be used with nylon tube or pipe as well as with other types of plastic or metal pipe.


   



    Glass


    In some specialized industrial fluid process settings, glass pipe and fittings are employed. Borosilicate glass offers several key advantages over alternative forms of piping systems. The material has high purity, so it will not contaminate process fluids. The natural transparency of glass permits the inspection of the process as needed, while the smooth surface prevents the development of scale or other residues on the interior surface of the pipe.


   



    Laboratory applications may also frequently employ glass tubing and glass profile fittings.


   



    Glass pipe should not be confused with pipes that employ a glass lining, which would be more correctly identified as glass-lined pipe.


   



    Vitrified clay


    Fittings for vitrified clay pipe are available in the typical configurations required for sewer installations. Like cast iron, bell-and-spigot is the usual coupling method for these fittings, with an O-ring or gasket used to seal the joint.


   



    Types of Pipe Fittings: Applications and Industries


    Callouts


    Threaded fittings follow a standardized format on drawings. The nominal dimension comes before the description. When two or more ends of the fitting are not of the same dimension, the dimension of the run precedes those of the branches, or for reducing fittings, the largest dimension precedes the smallest dimension. Thus, a 1 x 1 x 3/4 Street Tee; a 1 x 1x 3/4 45° Y Bend; a 1 x 3/4 x 1/2 x 1/4 Cross; and so forth. The thread size on threaded fittings will correspond to the nominal pipe size thread as specified by ANSI.


   



    Thread Types


    Most pipe applications use threaded fittings whose connections can be typically characterized by one of the following systems:


   



    American National Standard Pipe Threads (NPT)


    British Standard Pipe Threads (BSPT)


    The principal difference between these two is the taper angle. The NPT system uses a thread taper angle of 60 degrees, whereas the British Standard Pipe Thread (BPST) fittings use a slightly lower taper angle of 55 degrees. In addition to threaded pipe fittings which are tapered, these systems also specify straight pipe thread fittings, which do not rely on a taper to seal against pressure loss or leaks. Generally, a suitable sealant is needed to assure that the seal integrity of the joint or connection is achieved. Most threaded pipe fittings are designed to be right-hand threads, but there are some left-handed (LH) thread options available.


   



    Metric pipe fittings are also available, identified by the nominal outside diameter and the thread pitch. So an M12 x 1.5 metric pipe nipple would have an outside diameter of 12 millimeters and a thread pitch of 1.5 threads per millimeter.


   



    Screw fittings are usually threaded internally. The exception is the street fitting, which, in the case of a simple elbow, has one external thread and one internal thread. Pipes are readily threaded in the field. Joining threaded pipes and fittings can be aided by Teflon tape or pipe compound. When applying the compound, it is recommended that it be placed on the external thread only, to avoid introducing any impurities into the pipeline during joint assembly.


   



    Piping layouts are generally one-line or two-line drawings, depending on the complexity of the installation. Where clearances are tight,and for many shop-fabricated pipelines, the two-line drawing is used, which shows the pipe dimensionally to scale. For simpler installations, the one-line drawing suffices, with fittings, valves, etc. designated symbolically. Pipeline drawings are sometimes shown as “developed,” which assumes the vertical pipes are revolved into the horizontal plane, or vice versa, to allow the entire piping system to be shown in the same plane.


   



    Weldolets


    These small, weldable branch fittings reinforce the pipe where a hole is made, eliminating the need to add reinforcing. Different forms of these fittings are available under various trademarks, covering butt- and socket-welded styles, thread-on varieties, as well as some special designs which enable connections at elbows, etc.


   



    Welding process


    Pipe ends and flanges are prepared for butt welding according to pipe-wall thickness. For walls 3/4 inch thick or less, the walls are beveled to an included angle of 70° and a 3/16 inch gap is left between them. The welder makes a root pass, a fill pass (or passes), and a capping pass, often varying the filler material between passes. For larger thickness, the pipe is tapered to a similar angle but only partway up the wall. In addition, a small relief angle is ground on the inside wall, serving as the location for a backing ring. Socket welds are generally used for thinner-walled pipes. Welding procedures are spelled out by an engineer in Weld Procedure Specifications and the welder making the weld will be certified for the specific process. Pipes sometimes must be preheated prior to welding and heat-treated after to relieve heat stress.


   



    The necessity of proper pipe-end preparation and the need for careful fit-up prior to joining butt-welded fittings makes the use of socket-weld fittings appealing. No bevel is required for socket-weld fittings and the socket itself serves to align the pipe. About the only special requirement is that the pipe must be backed out of the fitting slightly to allow for expansion during the weld.


   



    Prefabrication of pipeline sections, called “spools,” is often done indoors where automation can be applied to the fabrication process. Pipes joints can be rolled on slow turning machines to bring the work to the welder. Robot welders can be used. Techniques such as submerged-arc welding can be applied for productivity gains.


   



    There are non-welded pipe fittings or no weld pipe connectors available as alternatives to the traditionally welded piping systems. Using a combination of swaged mechanical fittings along with the cold bending of pipe or tubing, this solution eliminates the stresses to the pipeline from the welding operation, reduces costs, and can provide for a modular system that is easier to disassemble or modify as needed.


   



    Plastic pipe, and HDPE pipe, in particular, can be joined by heat welding, sometimes referred to as electrofusion welding. Pipes can be butt-welded or socket-welded. This is a fairly common practice for large-diameter HDPE pipeline installations. A range of specialized equipment is available for producing these welds.

Are Blankets the New Going-Out Accessory?

    Are Blankets the New Going-Out Accessory?


    From Sarah Jessica Parker’s monogrammed Burberry poncho to Norma Kamali’s Sleeping Bag Coat, fashion has long embraced blanket-inspired styles. During a time when most socializing takes place outdoors, would you wear one outside the house?


    A weighted blanket is exactly what it sounds like - it’s a blanket with extra weight in it. Weighted blankets are unique as instead of being filled with cotton or down, it contains materials like glass beads to make them heavier. This weight is evenly distributed across the body for a feeling of being gently hugged. The deep touch pressure offered by the weighted blanket is supposed to make you feel safe, relaxed, and comfortable.


   



    Blankets, a symbol of coziness and warmth usually relegated to the indoors, can also be a great piece to layer for fall and winter outfits. Though temperatures are just starting to drop in New York City, WSJ. staffers have spotted a few in the wild—mostly while outdoor dining, which New York City recently extended permanently. (It was originally set to expire ahead of the winter months, on October 31.) For the first time in recent history, the preferred environment for socializing has become “anywhere outside.” And during a pandemic and period of worldwide unrest, most people are seeking comfort more than ever. As a replacement for the timeworn going-out top—obviously better suited to the indoors—the going-out blanket suddenly makes sense.


   



    Over the years, blankets have inspired fashion, from the upscale double layers blanket poncho that Sarah Jessica Parker wore in 2014, personalized with her initials, to Norma Kamali’s famous blanket-adjacent Sleeping Bag Coat, which she first designed in 1973. In 2012, Lenny Kravitz went viral after being photographed by paparazzi while ensconced in an enormous scarf on his way to buy groceries. Six years later, he defended the accessory on an episode of The Tonight Show Starring Jimmy Fallon. “But Lenny,” Fallon said, “this is not a scarf. This is a blanket.”


   



    After my sister gave me a weighted blanket for Christmas, it became the gift that I didn't know I needed. It's one of the best things ever to happen to me.


   



    As someone with anxiety, I've struggled with restful sleep: Falling asleep can take up to two hours, or I wake up at least twice during the night.


    The first night I started sleeping underneath a 15-pound flannel blanket, I slept straight through the night for the first time in months and felt more rested during the day. After a few days of good sleep, I learned that my sister had done her gift research — she had read that people with anxiety tended to feel more grounded when using the blankets.


   



    Fascinated, I asked experts on mental health and sleep to explain why these heavy blankets — which are filled with plastic, glass or metal particles and layered with extra fabric — have eased the, ahem, weight of some people's anxiety-related sleep struggles.


    Weighted blankets, which range from 5 to 30 pounds (2.27 to 13.6 kilograms), have been used by special needs educators and occupational therapists since the late 1990s, but have become mainstream in the last few years. Regular blankets can weigh around 3 to 5 pounds.


    The dominant theory is that weighted blankets provide deep pressure stimulation, a feeling that resembles a "firm, but gentle, squeeze or holding sensation and ... triggers these feelings of relaxation and of being calm," said pulmonary and sleep specialist Dr. Raj Dasgupta, an assistant professor of clinical medicine at Keck School of Medicine at the University of Southern California. Feeling relaxed is what decreases cortisol, a stress hormone that typically runs high in people with chronic anxiety, stress and other disorders, he added.


    There is evidence suggesting that deep pressure stimulation reduces sympathetic nervous system arousal — that's our fight-or-flight response — and increases parasympathetic activity, which may cause the calming effect, said Dr. Fariha Abbasi-Feinberg, the director of sleep medicine at Millennium Physician Group in Florida.


   



    Pressure to stimulate the sensation of touch to muscles and joints is the same proposed mechanism behind massage and acupressure, added Abbasi-Feinberg, who is also a neurologist on the American Academy of Sleep Medicine's board of directors. "This calming (effect) can promote better quality sleep."


    If you're interested in using a weighted blanket to aid sleep problems related to mental or sensory disorders, here's what you should know about their effectiveness, any caveats and how to choose one.


   



    Weighted blankets have been growing in popularity, but there isn't actually much research on their effectiveness. That may be due to the newness of weighted blankets, their relative harmlessness and that other health issues are more urgent for researchers to study, Dasgupta said.


    Some people with anxiety, depression, bipolar disorder or insomnia have reported improved quality of sleep and feeling more restful during the day, a few recent, small studies have found. Many study participants experienced a decrease of 50% or more in their Insomnia Severity Index scores after using a weighted blanket for four weeks, in comparison to 5.4% of the control group, according to a small study published in the Journal of Clinical Sleep Medicine last September.


   



    In the follow-up phase of the study, which lasted one year, people who used fleece blanket continued to benefit. People who switched from lightweight control blankets to weighted blankets experienced similar effects. And those who used weighted blankets also reported better sleep maintenance, a higher daytime activity level, remission from insomnia symptoms and alleviated symptoms of anxiety, depression and fatigue.


    Researchers who studied the effects of weighted blankets on children with attention-deficit/hyperactivity disorder or autism have found either some positive associations or no associations with better sleep or reduced symptoms.


    "A 'grounded feeling' due to the use of weighted blankets may be attributed to the psychoanalytic 'holding environment' theory, which states that touch is a basic need that provides calming and comfort," Abbasi-Feinberg said via email. "Weighted blankets are designed to work similar to the way tight swaddling helps newborns feel snug and secure."


   



    Many, if not all, of the available studies on weighted blankets used participants who had a psychiatric, developmental or sleep disorder such as anxiety, depression, autism, ADHD or insomnia. That's likely because of "the fact that these segments of the population are the ones who could benefit most from touch- or sensory-related therapies," Abbasi-Feinberg said.


    However, given how weighted blankets might work to reduce cortisol levels, they could help to reduce general stress, too, Dasgupta said.


   



    People have shared their fondness for weighted blankets in studies and online, but people with the same psychiatric disorders may not have the same relaxing experiences with weighted blankets. One person in the follow-up phase of the 2020 study discontinued their participation due to feelings of anxiety when using the blanket. People who are claustrophobic may also not fare well. More studies on factors that make individuals more or less helped by weighted blankets are needed, Dasgupta added.


   



    A weighted blanket's calming abilities may help to regulate breathing, but some health professionals are hesitant to recommend weighted blankets to people with obstructive sleep apnea, asthma or other respiratory conditions. "You'd have to be pretty brittle and pretty sick if a blanket's going to stop your breathing," Dasgupta said. But if you're not sure, he added, be careful and talk to your pulmonologist first.


    Children should be assessed by occupational therapists or pediatricians before they try sherpa blanket, as many weighted blankets haven't been tested for the effectiveness and safety for children.


    "Weighted blankets shouldn't be used for toddlers under 2 years old, as it may increase the risk of suffocation," Abbasi-Feinberg said. "It's important for parents to always consult their pediatrician before trying a weighted blanket."


    Dogs sometimes benefit from pressure-applying garments during storms or other anxiety-inducing events, but weighted blankets can be dangerous for pets, said Dr. Douglas Kratt, president of the American Veterinary Medical Association.


   



    If you're looking for a weighted blanket, there are multiple options in terms of weight, materials and size. A blanket that weighs 7% to 12% of your body weight is typically the range to choose from, but that may depend on personal preference. "Some individuals might want a heavier weight to feel a sense of 'hugging' and calmness, while others might want something lighter," Abbasi-Feinberg said.


   



    And there are weighted blankets for year-round use, she added — some are made with a higher proportion of fabric layers made from cotton, which is lighter than other materials and allows air to pass through its fibers, therefore better managing your body temperature.


    Dasgupta thinks of sleep as a puzzle, and sometimes people with insomnia or mental disorders are missing some of the pieces needed for great sleep, but "no one really knows what puzzle pieces are missing."


    Weighted blankets could help, but they're not a cure-all — a healthy sleep routine is still necessary for getting enough of both sleep time and the deeper stages that leave you refreshed. If you think that a weighted blanket could be your missing puzzle piece, "it's worth a try," Dasgupta said. The downside is that these blankets can be pricey.


    During the pandemic, "sleep really took a hit" when it comes to insomnia, altered circadian rhythm and nightmares, Dasgupta said. "A weighted blanket is something that might have a role during this pandemic. ... That sense of the basic need to be touched and hugged could actually provide some comfort and security. Maybe that's why some people benefit from a weighted blanket."

Environmental impacts of wooden, plastic, and wood-polymer composite pallet: a life cycle assessment approach

    Environmental impacts of wooden, plastic, and wood-polymer composite pallet: a life cycle assessment approach


    Waste recycling is one of the essential tools for the European Union’s transition towards a circular economy. One of the possibilities for recycling wood and plastic waste is to utilise it to produce composite product. This study analyses the environmental impacts of producing composite pallets made of wood and plastic waste from construction and demolition activities in Finland. It also compares these impacts with conventional wooden and plastic pallets made of virgin materials.


   



    Methods


    Two different life cycle assessment methods were used: attributional life cycle assessment and consequential life cycle assessment. In both of the life cycle assessment studies, 1000 trips were considered as the functional unit. Furthermore, end-of-life allocation formula such as 0:100 with a credit system had been used in this study. This study also used sensitivity analysis and normalisation calculation to determine the best performing pallet.


   



    Result and discussion


    In the attributional cradle-to-grave life cycle assessment, wood-polymer composite pallets had the lowest environmental impact in abiotic depletion potential (fossil), acidification potential, eutrophication potential, global warming potential (including biogenic carbon), global warming potential (including biogenic carbon) with indirect land-use change, and ozone depletion potential. In contrast, wooden pallets showed the lowest impact on global warming potential (excluding biogenic carbon). In the consequential life cycle assessment, wood-polymer composite pallets showed the best environmental impact in all impact categories. In both attributional and consequential life cycle assessments, plastic pallet had the maximum impact. The sensitivity analysis and normalisation calculation showed that wood-polymer composite pallets can be a better choice over plastic and wooden pallet.


   



    Conclusions


    The overall results of the pallets depends on the methodological approach of the LCA. However, it can be concluded that the wood-polymer composite pallet can be a better choice over the plastic pallet and, in most cases, over the wooden pallet. This study will be of use to the pallet industry and relevant stakeholders.


   



    Pallets are used for storing, protecting, and transporting freight. They are the most common base for handling and moving the unit load, carried by materials handling units, such as forklifts. The pallet market is growing due to the rising standard of goods transportation, the adoption of modern material handling units in different industries, and market demand for palletised goods (McCrea 2016). It was estimated that the global pallet market reached 6.87 billion units in 2018 (Nichols 2020). More than 600 million European Pallets Association (EPAL) approved pallets are available to the global logistics industry. In 2019, 123 million wooden EPAL pallets and other carriers were produced, which is 1.2 million more compared to 2018 (EPAL 2020).


   



    The global pallet market can be classified based on materials, sizes, and management strategies (Deviatkin et al. 2019). Among various segments of pallets, wooden pallets dominate the market share, followed by plastic pallets (Leblanc 2020). Wooden pallets are inexpensive and can easily be manufactured and repaired compared to rackable plastic pallets. One of the most significant downsides of wooden pallets is the cost to forests (Retallack 2019). Furthermore, wooden pallets are heavier than plastic pallets, imposing an environmental burden on freight shipment. Even though plastic pallets are lighter than wooden pallets, plastic pallets’ production is an energy-intensive process. In addition, repairing plastic pallets is impossible because the materials have to be melted down and remoulded in the plastic pallet repairing process.


   



    Waste recycling is one of the pathways taken by the European Union to move towards a circular economy, as highlighted in the circular economy action plan (European Commission 2020). The central idea of a circular economy is to minimise the consumption of virgin materials, which means that an item that can be recycled should not be landfilled or incinerated. The EU is planning to recycle 50% plastic and 25% wood waste by 2025, which will increase to 55% for plastic and 30% for wood by 2030 (European Commission, 2018). By following the EU’s target, Finland’s objective is to fortify its role as a pioneer in the circular economy by implementing the strategic programme for circular economy (Ministry of Employment and the Economy 2021). The transition to a circular economy is essential for Finland to strengthen its export-driven economy with minimum environmental impact.


   



    The environmental benefits of recycled-based plastic products are well known and quantifiable (WRAP 2019). Also, materials made from wood waste can deliver low carbon-based products with less pressure on forests (WWF 2016). One of the possibilities for reducing the environmental burden of plastic and wood waste is to utilise these wastes for wood-polymer composite (WPC) products, such as WPC pallets. However, analysing the environmental performance of WPC pallets requires a complete life cycle analysis. Furthermore, it is important to consider that different materials have different life expectancies, reuse capabilities, and recyclability.


   



    According to International Organization for Standardization (ISO), life cycle assessment (LCA) is one of the environmental management techniques that “addresses the environmental aspects and potential environmental impacts throughout a product’s life cycle from raw material acquisition through production, use, end-of-life treatment, recycling, and final disposal” (EN ISO 14040:2006; EN ISO 14044:2006). Several LCA studies have been conducted on pallets focusing on pallet manufacturing, management strategies and supply chains, repair intensity, and pallets manufactured from various materials, such as wood, virgin plastic, cardboard, and waste plastic. Gasol et al. (2008) conducted an LCA study to compare the environmental performance of wooden pallets with high reuse intensity and low reuse intensity in the European context, and with the findings showing that due to transportation, high reuse intensity pallets have more adverse impacts on climate change than low reuse intensity pallets. Bengtsson and Logie (2015) performed an LCA comparing one-way wooden pallets, disposable compressed cardboard pallets, pooled softwood pallets, and plastic stackable pallets in Australia and China. The study results pointed out that pooled softwood pallets have the minimum environmental impact among all types of studied pallets. Tornese et al. (2018) examined pallets’ economic and climate change impacts, demonstrating that manufacturing a pallet causes more damage to the environment than repairing a pallet. The study also identified that the cross-docking system has equivalent emissions as the take-back system due to higher transportation distance. Almeida and Bengtsson (2017) compared the LCA of waste plastic-based pallets with wooden pallets and virgin plastic-based pallets and demonstrated that plastic waste-derived pallets outperform all other alternatives. Franklin Associates (2007) compared the environmental impacts of pooled pallets versus non-pooled pallets. The study indicated that pooled pallets have less of an environmental burden than non-pooled pallets. Ko?í (2019) studied the environmental impact of wooden pallets, primary plastic pallets, and secondary plastic pallets. The study found that wooden pallets have a better environmental impact than primary and secondary plastic pallets if energy recovery occurs. Furthermore, the study also showed that the weight of the pallet plays a significant role on its total environmental impact.


   



    The authors of previously conducted LCA studies analysed various pallets, making their cross-comparison a difficult task. Previous literature, including the above mentioned studies, have conducted LCA from an attributional point of view and excluded consequential LCA, which is thought to be an important method for identifying the changes in the system as a consequence of using a particular pallet. It is important to investigate the differences in the results, conclusions, and suitability of attributional and consequential LCA for cases where waste recycling is included. Furthermore, all the former studies assumed that various pallets perform equally well during their life cycle. None of the studies considered that pallets made with different materials have different life expectancies, repairing times, and recycling rates. In addition, end-of-life (EoL) is an integral part of the cradle to grave LCA. The methodological difference of the EoL allocation might have a significant impact on the overall result of LCA. It is found that the allocation of the environmental burdens of the EoL of the pallets was absent in the studies as mentioned earlier.


   



    The goal of this LCA study was to calculate and assess the environmental impacts of manufacturing, utilising, and disposal of pallets made of different materials. Both attributional LCA (ALCA) and consequential LCA (CLCA) methods were used in the study. An ALCA investigates the environmental impact of the physical flows to and from a product’s life cycle and its subsystems (Ekvall et al. 2016). In contrast, consequential LCA investigates the environmental impacts of the product system and the systems linked to it that are expected to change for production, consumption, and disposal of the product (Ekvall et al. 2016). Despite the ISO 14040/44 standards not explicitly distinguishing between the two types of LCAs, there is a clear difference in the definition of the scope for those assessments, as described below. The study results are intended to guide the selection of materials for the production of pallets.


   



    Scope of the ALCA study


    The attributional LCA follows the cradle-to-grave approach, meaning that the product system includes the processes starting with the provision of raw materials from the environment in the form of elementary flows, i.e. the flows created by nature, through the use of the pallets and ending with their disposal and with the release of emissions into air and water, and to the generation of waste.


   



    The system boundary of the ALCA comparing the impacts of the pallet’s production, use, and EoL is shown in Fig. 1. The modelling started with producing the raw materials and the energy generation for the pallets, such as wood harvest, timber production, and plastic production. It should be noted that the system boundary for WPC starteds from the collection of waste. Once the materials are produced and delivered to the production facilities, the pallets are manufactured. Nails are used to secure the parts of the wooden pallets, whereas plastic and WPC pallets are compressed into the required shape and do not require any fixing elements. The pallets are then delivered to a pallet pooling company, which operates by delivering the produced pallets to customers who can use them for their own purposes. After which, the pooling company collects the pallets and repairs them in the case of wooden pallets, if needed. After being used, the pallets are crushed for incineration. In the case of wooden pallets, ferrous metals are separated before incineration. By incinerating wooden, plastic and WPC pallets’ waste, energy is substituted. Nevertheless, materials are also substituted by separated ferrous metals from wooden pallets.


   



    EoL allocation


    There are no strict or specific requirements for modelling the EoL in LCA, and several allocation methods exist, such as 0:100 approach, 100:0 approach, 100:100 approach, 50:50 approach, etc. (Allacker et al. 2017). 0:100 EoL method can be conducted in two different ways, such as 0:100 with no credit for avoiding virgin materials and 0:100 with credit for avoiding virgin materials (Allacker et al. 2017). The system boundary of the study ends at the recovery of energy and material from the EoL phase. Therefore, in this study, the 0:100 EoL method with credit system had been used.


   



    In the CLCA, the correct way of modelling environmental impact is to use marginal production technology data for the substituted product. Marginal production technologies are those technologies that are changed by the small changes in demand (Weidema et al. 1999). It was found from this study that a significant amount of heat and electricity substitution was impacted when wood and plastic waste were not incinerated but used for WPC pallet production. In this case, marginal heat and electricity were used in the modelling of CLCA. Biomass will be the prime heat production source in Finland by 2030 (Ministry of Employment and the Economy 2017), and wind and solar power will provide the maximum share of electricity by 2030 (SKM Market Predictor 2019). Therefore, the biomass-based heat source was selected as the marginal heat source and wind, and solar-power-sourced electricity was selected as the marginal electricity source in CLCA modelling. The more detailed information on the selection of marginal heat and electricity is presented in the supplementary materials.


   



    Selection of the pallets


    A great variety of pallets exists, as dictated by the specific requirements of customers. However, this study exclusively focused on pooled pallets, with the dimension of 1200 mm?×?800 mm, made of either wood, plastic, or WPC. The pallets with the above-specified dimension are widely known as EUR pallets and are the most widely used type of pallets in Europe (EPAL 2019).


   



    Table 1 specifies the key parameters of the studied pallets in their baseline scenario. Wooden pallets are made of virgin wood, which is a mixture of softwood and hardwood as specific to Finnish conditions. The studied wooden pallets were block-type pallets, which are commonly used in Europe. Based on the review of LCA studies of wooden and lightweight plastic pallet by Deviatkin et al. (2019), the expected lifetime of the wooden pallets is 20 cycles, yet the number ranged between 5 and 30 cycles in most of the publications reviewed. The repair need of 7 cycles was estimated based on the mass of produced EUR pallets in Finland (3.2?×?103 kg), alongside with repaired (25?×?103 kg) and reused (167?×?103 kg). The expert views from a Finnish pallet pooling company suggested that the expected lifetime of the wooden pallets is somewhat higher, whereas the repair need for the pallets occurs on average after every 12 cycles. The variations in the expected lifetime of the pallets were examined in the scenario analysis of this study. It was assumed that, at the EoL, 90% of wooden pallets are incinerated, whereas 10% are used as a bulking agent in composting facilities.


   



    The plastic and WPC pallets are identical in structure and production method. Plastic pallets are manufactured using injection moulding, whereas WPC pallets are produced by extrusion followed by a compression moulding process. Both pallets are made to allow their nesting, thus saving the space occupied by the pallets. The exact height occupied by wooden stackable pallets can fit 1.7 times more plastic or WPC pallets. According to the literature on plastic pallets, plastic pallets are more durable than wooden pallets (Deviatkin et al. 2019). The expected lifetime of Double Sided Plastic Pallets could be 66 cycles, whereas the lifetime ranges from 50–100 in most of the studies reviewed (Deviatkin et al. 2019). In this study, the lifetime of plastic pallets was considered to be 66 cycles by following the review study conducted by Deviatkin et al. (2019). The WPC pallets were assumed to be of comparable properties as plastic pallets in these terms. Plastic and WPC pallets are suitable for demanding applications, such as those with expected exposure to water, or specific industrial demands, like those of the pharmaceutical industry. Such features of plastic and WPC pallets are, however, not considered in this study. Once damaged, neither plastic nor WPC pallets can be repaired. 

The Science of LED Grow Lights for Your Indoor Garden

    The Science of LED Grow Lights for Your Indoor Garden


    Indoor Gardening isn’t exactly a new thing, but LED’s are changing the way we light our indoor gardens.  LED lights are more efficient than traditional fluorescent and incandescent lights.  That’s because LED lights convert nearly all of their energy (95%) into light, while other lights turn a significant amount of energy into heat.  But, there’s another very important reason that LED’s are more efficient when it comes to growing plants.  With LED lights, we have the rather unique ability to customize the type of light that is emitted, and that means we’re not wasting energy to create light that doesn’t help our plants grow.  At the end of this article, you’ll understand the science behind why spyder grow light series come in many different colors, as well as why some LED grow lights cost so much more than others. 


   



    Plants Only Use the Visible Light Spectrum for Photosynthesis


   



    It’s important to know that plants only use visible light (the colors of light that we see every day) for photosynthesis. However, as the chart below demonstrates, the complete spectrum of light is far greater than just the visible light spectrum.  On the outer edge of the visible light spectrum is Ultraviolet (UV) light and Infrared Radiation (IR).  UV light is the invisible light emitted by the sun and other sources that will cause sunburns when we don’t wear sunblock.  IR light can only be seen with special equipment, like night-vision goggles.  Even further out from the visible light spectrum are light waves that we don’t traditionally think of as light.  These include X rays, Microwaves and even Radio Waves.


   



    One of the most important things to understand is that scientists have demonstrated over and over again that plants only absorb visible light for photosynthesis.  Plants do react to other forms of light like UV, but that reaction is typically negative.  I’m told that marijuana growers actually use UV light to induce the production of psychoactive chemicals like THC, which seem to be produced in part as a defense mechanism against the damaging effects of UV light to the plant.


   



    What is PAR?


   



    PAR stands for “photosynthetically available radiation.”  PAR is made up only of visible light, because this is the only light that plants use for photosynthesis.


   



    For decades, many indoor growers have used Lumens to measure a grow light’s efficacy, but the industry is getting smarter and turning to PAR.  Lumens are used to measure the brightness of a lamp to the human eye.  But plants and people see light differently.  Humans see yellow and green more brightly than other colors.  Therefore, yellow and green lamps may have higher Lumen values than red and blue lights that put out just as much actual light, and which plants are likely to respond better to.


   



    PAR measures all light from the visible light spectrum equally, and does not measure light outside of the visible light spectrum, which does not help the plant photosynthesis.  So, for plants, the PAR value of a light is currently the best basic measurement of a grow light’s brightness.  Accurate PAR meters are quite expensive and generally cost $500 or more.  Inaccurate PAR meters can be purchased for much less, but there’s really no point to owning an inaccurate PAR meter. 


   



    The best way to get PAR values for your 400W LED grow light, assuming you don’t want to purchase your own PAR meter, is to check with your reputable grow light manufacturer or provider for the PAR rating of their lights. 


   



    How Much PAR do My Plants Need to Grow?


   



    The amount of PAR your plants require depends on what you are growing, as well as how far away from your plants the light is.  Generally speaking, leafy greens like lettuce only need a PAR value of ~200, whereas tomatoes and other plants that flower and produce fruit require 400-500 or more PAR.  Unless you place your 600W LED grow light right on top of your produce, you will need an even higher PAR rating from your grow light, to take into account the distance between your plant and the light source.


   



    In the example below, you can see a very powerful grow light that puts out nearly 1,900 PAR (measured in umol) 8 inches from the source.  Very few lights put out this much PAR, and they are typically quite expensive.  This light will emit 1,900 umol every second.  But at 23 inches from the source, the strength of the light is reduced to 890 umol.  The PAR value is reduced further and further as you get further from the light source.  When we get to 6 feet away from the light source, our PAR value is down to ~100umol, which means we would have trouble growing even lettuce well.  So, always make sure you understand not just the PAR emitted from the light, but that every 8 inches or so away from your light, the PAR value will be reduced by ? or more.


   



    There are many inexpensive grow lights on the market that make big claims, but they will ultimately leave their owners disappointed.  This issue is especially rampant on the internet.  Remember to check the PAR value of any light you purchase.  Also, remember to take into account how far your light will be from your plant to ensure there is enough photosynthetically available radiation (PAR) for your plant to flourish.


   



    Leafy Greens require 200 PAR for proper growth


    Tomatoes, cucumbers and other flowering/fruiting vegetables require 400-500 PAR


    Fruiting Trees should be given 600 PAR or more


    What is the Temperature of Light I Should Use?


   



    Interestingly, ‘Kelvin temperature’ is the metric used to describe the visual color that a light emits.  As you can see in the chart below, ‘warmer’ light temperatures that have a red color have a lower Kelvin rating.  On the other end of the spectrum are ‘cooler’ temperature lights which have a blue color and higher Kelvin rating.


   



    Different temperatures of light have different impacts on plants.  Generally, higher temperatures (blue) light encourages photosynthesis which leads to bushy plants that don’t feel inclined to elongate and reach for more light.  This is great if you want to grow in a compact space.  Lower temperature (red) light reduces photosynthesis and signals to plants that that it’s time to flower and produce fruit.  Plants put under a red light will also be more inclined to stretch and grow taller, as opposed to growing bushier and more compact.


   



    IGWorks focusses on providing full spectrum lights with a natural color temperature of between 4500K-6500K as these are most pleasing to the eye.  They also allow plants to grow bushy and compact, without hindering the ability of plants to flower and fruit. 


   



    What Color of Light Should I Use?


   



    LED lights can come in almost any color.  Plants respond most to red and blue light.  Interestingly, plants generally respond less well to green light.  In fact, the reason that plants appear to be green is that they tend to reflect green light, while they absorb other parts of the light spectrum more readily.  This is why a large scale or industrial grower of plants will often use a combination of red and blue lights to photosynthesize their plants.  They don’t want to waste electricity producing green and even yellow light, which plants use less effectively. 


   



    However, for those of us growing produce in our living spaces, it’s probably worth the extra pennies it costs to produce a nice full-spectrum color that will be more natural and pleasing to the eyes.  Full-spectrum grow lights will often come with a chart, which shows the distribution of blue, green, yellow and red light that is emitted.  See the example below


   



    Choosing the right grow light spectrum for your commercial operation can be a challenge. Many 800W LED grow light suppliers have conflicting information on the topic due to bad marketing or simply a lack of knowledge in plant and light research.


   



    In this article, our light spectrum experts break down what light spectrum is, how plants respond to light, and how light spectrum influences plant growth.


   



    What is Grow Light Spectrum?


    Light spectrum is the range of wavelengths produced by a light source. When discussing light spectrum, the term ‘light’ refers to the visible wavelengths of the electromagnetic spectrum that humans can see from 380–740 nanometers (nm). Ultraviolet (100–400 nm), far-red (700–850 nm), and infra-red (700–106 nm) wavelengths are referred to as radiation.


   



    As growers, we’re most interested in the wavelengths that are relevant to plants.  Plants detect wavelengths that include ultraviolet radiation (260–380 nm) and the visible portion of the spectrum (380–740 nm) which includes PAR (400–700 nm), and far-red radiation (700–850 nm).


   



    When considering light spectrum for horticultural applications, greenhouse and indoor environments will differ.  With indoor environments your grow light’s spectrum will account for the total light spectrum that your crop receives.  Whereas in a greenhouse you must consider that your plants are receiving a combination of folding grow light series and solar spectrum.


   



    Either way, the amount of each waveband that your crop receives will have significant effects on growth.  Let’s learn more about how this works.


   



    Plants use light for photosynthesis and photomorphogenesis. Photosynthesis is the process by which plants and other organisms convert light energy into chemical energy. Photomorphogenesis refers to how plants modify their growth in response to light spectrum.


   



    One example of photomorphogenesis is a plant bending toward a light source. Light also affects plants’ developmental stages, such as germination and flowering.


   



    The light that plants predominately use for photosynthesis ranges from 400–700 nm. This range is referred to as Photosynthetically Active Radiation (PAR) and includes red, blue and green wavebands.


   



    Photomorphogenesis occurs in a wider range from approximately 260–780 nm and includes UV and far-red radiation.


   



    Although results are dependent on other factors, there are general rules of thumb that you can follow when using light spectrum to elicit different plant responses.


   



    Outlined below is an overview of how each waveband is used for horticultural purposes so that you can trial light spectrum strategies in your own growth environment and with your chosen crop varieties.


   



    Blue light has distinct effects on plant growth and flowering. In general, blue light can increase overall plant quality in many leafy green and ornamental crops.


   



    A minimal amount of blue light is required to sustain normal plant development.  In terms of adjustable spectrum lighting strategies, if we were to equate red light to the engine of your car, then blue light would be the steering wheel.


   



    When combined with other light spectrum wavebands, blue light promotes plant compactness, root development, and the production of secondary metabolites.   Blue light can be utilized  as a growth regulator, which can reduce your need for chemical plant growth regulators (PGRs). Blue light can also increase chlorophyll accumulation and stomatal opening (facilitating gas exchange), which can improve overall plant health.


   



    One example of blue light influencing secondary plant metabolite production is how blue wavebands promote anthocyanin development in leaves and flowers. Increased anthocyanin levels result in more pronounced color.


   



    Blue light also promotes other secondary metabolic compounds associated with improved flavor, aroma and taste. For example, blue light treatments have been shown to improve terpene retention in some varieties of cannabis.


   



    Higher intensities of blue light (>30 μmol·m-2·s-1) can inhibit or promote flowering in daylength-sensitive crops. Blue light does not regulate flowering at low light intensities (<30 μmol·m-2·s-1), so is safe to be applied at night to influence the other plant characteristics listed above


   



    Since chlorophyll does not absorb green light as readily as other wavelengths, many have written off the green waveband as being less important to plant growth. This lower chlorophyll absorption rate, compared to blue and red light, is what makes most plants appear green. Depending on the plant, leaves generally reflect 10-50% of green waveband photons.


   



    In contrast to assumptions, studies of green light in crop production have concluded that green light is important to photosynthesis, and especially in a plant’s lower leaves. Around 80% of green light transmits through chloroplasts, whereas leaves absorb approximately 90% and transmit less than 1% of red and blue light.


   



    So what does this all mean? When light is plentiful, chlorophyll reaches a saturation point and can no longer absorb red and blue light. Yet, green light can still excite electrons within chlorophyll molecules located deep within a leaf, or within chloroplasts lower in the plant’s canopy. And so, green light enhances photosynthetic efficiency—potentially increasing crop yields, during bright light conditions.


   



    Additionally, the ratio of green to blue and red wavelengths signals to the plant a leaf’s canopy position. This can induce morphological changes to maximize light absorption. Green light also plays a role in regulating stomatal aperture (opening and closing of plant pores that make gas exchange possible).


   



    Greenhouse applications require less supplemental green light since plants receive adequate green light from solar radiation.&nbsp; Indoor environments may benefit more from supplemental green light since no sunlight is present.

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Microfiber leather is an abbreviation of ultrafine fiber PU synthetic leather. It is a non-woven fabric made of three-dimensional structure network by carding acupuncture with microfiber staple fiber. After wet processing, PU resin impregnation, alkali reduction, and dermabrasion and polishing And other processes eventually make microfiber leather. It is made by adding ultra-fine fiber to PU polyurethane, which makes the toughness, air permeability and abrasion resistance further strengthened; it has extremely excellent abrasion resistance, excellent cold resistance, breathability, and aging resistance. Eco-friendly, Comprehensive performance beyond real leather. Widely used for automotive, garment, bags, sofa, shoes, boots, basketball, belt, jewellery box and so on. We are specialize in microfiber leather production manufacture.We provide the optimal leather options, the best leather substitute and best leather alternatives for automotive seat covers and interiors, furniture & sofa upholstery, footwear and shoes, bags, garments, gloves, balls, etc.

While synthetic leather were once considered not suitable for high quality shoes,  PU microfiber leather has changed how shoes are made.

Microfiber leather is designed to hold up against weather conditions and the wear and tear of walking and running over an extended period of time.

They can retain their form very well, and thus are usually very durable if cared for properly. They're also more water-resistant and lighter than real leather, making them great for long wear and outdoor activities.

We found this video, below, that tests how durable shoes made with suede microfiber leather are. Check it out!

Microfiber leather, or micro fiber leather, is the highest quality grade synthetic leather (faux leather or PU leather), a high-tech simulation of high-end leather material. WINIW Microfiber Leather is simulated the structure of natural leather, using sea-island superfine micro fiber (ultra-fine fiber bundle), and high-grade polyurethane resins as raw materials, using needle punched nonwoven technology of 3D structure, has a lot of similar characters as natural leather, however better physical & chemical performance, has been widely popular around the world. Because of superior performance, WINIW microfiber synthetic leather has been the best leather alternatives and the optimal leather substitute, material, best vegan leather and eco leather, can replace natural leather perfectly!

Compared to natural leather, microfiber synthetic leather has many excellent qualities, such as chemical resistance and physical and mechanical properties. However, preparation of microfiber synthetic leather with a high water vapor transmission rate (WVT), moisture absorption and wearing comfort property is still a challenge. In this study, we prepared thermoplastic polyurethane (TPU)/sulfonated polysulfone (SPSf) electrospun nanofibers and applied them to a microfiber synthetic leather base (MSLB). The effects of TPU/SPSf nanofiber content on the structure and properties of the MSLB were investigated. The results indicated that the TPU/SPSf nanofibers with an average diameter of 0.12 µm were well distributed at all directions in the MSLB. Differential scanning calorimetry analysis showed four Tg peaks, further demonstrating the existence of TPU/SPSf nanofibers. With the increase of TPU/SPSf nanofiber content from 0 to 30 wt%, the contact angles decreased gradually from 111.64° to 67.07°, leading to 55.19% improvement in the WVT value (from 2868.96 to 4452.24 g/(m2•24 h)) and 26.25% improvement in the moisture absorption (from 628.70% to 793.75% mm/s). Simultaneously, when the nanofiber content was 30 wt%, the nanofibers tended to bundle and 6.79% decrement of air permeability was observed. Specifically, the softness of the MSLB was improved by 88.55%. Moreover, the thermal stability and the tear strength were also obviously enhanced. Consequently, this research provided a feasible and promising way to prepare a high-performance MSLB using TPU/SPSf nanofibers.

The difficulty in dyeing microfiber base filled with ordinary polyurethane presents a significant challenge in maintaining the uniformity and highly realistic appearance of the resulting products. In the present study, a type of acid-dyeable polyurethane (PU-MDEA; MDEA=N-methyldiethanolamine) was synthesized, and its chemical structure and dyeing properties were investigated. Nuclear magnetic resonance analysis indicated that cationic groups were successfully incorporated into the PU-MDEA backbone via chain extension using MDEA. The amorphous nature of PU-MDEA was determined by differential scanning calorimetry, X-ray diffraction, and polarizing optical microscopy. Owing to the strong binding between these cationic groups and acid dye, as well as the reduced resistance to dye penetration, PU-MDEA showed better dyeability toward the acid dyes studied herein when compared with the control sample (microfiber synthetic leather filled with ordinary polyurethane). The adsorption isotherm experiment revealed that the dyeing process conformed to the Langmuir model, thereby indicating that the acid dyes attached to PU-MDEA via strong ionic bonding rather than van der Waals forces or hydrogen bonding. Additionally, it was found that the wastewater resulting from the dyeing of the microfiber synthetic leather filled with PU-MDEA exhibited environmentally friendly characteristics when compared with that displayed by the control sample (microfiber synthetic leather filled with ordinary polyurethane). Thus, the current results show the potential of PU-MDEA, as a filler, in the manufacture of microfiber synthetic leather to achieve fast dyeing rate, high dye uptake, and good color fastness, thereby improving the uniformity and highly realistic appearance of the resulting products.
Bonded leather is called ‘leather’ because it incorporates scraps of leather remnants, which comprise between 10-20% of its content. The scraps of leather are made into a pulp and stuck to a fibre or paper backer which is then coated with polyurethane and embossed to give it the appearance of genuine leather.

The price of an article is an immediate indication as to whether you are buying genuine leather. At a glance, bonded leather may look like the real thing but it will feel thin to the touch and will lack the softness of real leather, it may also exude a chemical smell.

WHAT IS BONDED LEATHER MATCH?
This term refers to the ability of bonded leather manufacturers to replicate the appearance of real leather, although it is likely that the product may be dyed in a striking range of unnatural colours.

For most people this will be a choice dictated by the comparative low cost of the product; some may choose bonded leather because it can be regarded as environmentally friendly, in so much as it uses left overs and does not involve additional farming and, potentially, reduces landfill. The product is also easy to clean and is likely to come in a wide range of design options.

Bonded leather should be wiped with a clean damp cloth and wiped dry with a different cloth. Spilt liquids should be cleaned immediately but no detergents or abrasive cleaners should be used. Non-alkaline cleaners and non-detergent soaps can be used but the material should always be tested for colour fastness on a small unobtrusive area first.

HOW DURABLE IS BONDED LEATHER?
Bonded leather is not a durable product. Generally, furniture made from bonded leather is likely to peel and crack within two to five years.

WHAT CAUSES BONDED LEATHER TO PEEL AND CRACK? 
Bonded leather is a non-elastic material; therefore, it has a tendency to crack with use, strips of polyurethane and leather will then start to peel away from the backing.

WHY IS BONDED LEATHER BAD?
Compared with leather, bonded leather has a very short lifespan. It is prone to cracking and peeling and once it has deteriorated beyond a certain point it is impossible to repair. Although a bonded leather may be cheaper than real leather, it’s short life span means that in the long run the cost of replacing a bonded leather item can be more expensive. There is also the argument that this also makes it less environmentally friendly.

HOW TO REPAIR BONDED LEATHER  
There are repair kits on the market which enable you to make small repairs to bonded leather. The affected area must be sanded to remove any protruding bits of leather, a patch can then be dyed to match or the fabric under the peel can be dyed and sealed to stop further peeling. The resulting repair will be noticeable but will be an improvement.

HOW TO FIX BONDED LEATHER SCRATCHES  
First clean the area with a white cloth to ensure that no dye is transferred. Then mix a leather repair solution together with an appropriate tint. Add a small quantity of the mixture to the affected area and around the affected area. Then place leather grained paper, supplied with the kit, over the area and gently iron with a warm iron, this will transfer the pattern to the repair. Be careful to ensure that the iron is not too hot because it may discolour or damage the bonded leather. For minor scratches, it may be possible to affect a repair with the use of shoe polish. You should also check any new products on a small inconspicuous area of the leather item first.

Top Grain leather is the second highest grade quality of leather and is the lower part of the top layer of the hide. One removed it is sanded and refinished. It comes in two grades, aniline, which is natural soft leather which is vulnerable to stains and semi-aniline which has a protective coating. Top Grain leather is comprised of twelve to fourteen percent water and consequently it adjusts to body temperature: it is cool in summer and warm in winter. With bonded leather the reverse is the case.

BONDED LEATHER VERSUS REAL LEATHER 
Real Leather, also referred to as Genuine Leather is the third grade of leather, taken from the lower, thinner layer of the hide. The surface is then reworked to resemble a higher-grade leather. It is not as tough as Full grain leather or Top Grain leather but is considerably more durable than bonded leather.

BONDED LEATHER VERSUS FAUX LEATHER 
Faux leather, sometimes referred to as Pleather, contains no animal products and is made from polyurethane. It can be embossed with any texture and looks and feels like genuine leather. It is water resistant and easy to clean. Unlike bonded leather it does not crack or fade in sunlight, it is however, easy to tear or puncture. It is also considered less environmentally friendly due to the chemicals and toxins used in its production – although this varies depending on the exact process and materials used to produce it.

BONDED LEATHER VERSUS DURABLEND
Durablend is a low-cost leather alternative, similar to bonded leather and comprising of 57% polyurethane, 26% poly/cotton and 17% leather shavings. It is the trademark product of Ashley Furniture. Customer reviews suggest that it shares similar weaknesses with bonded leather in so much as it scratches easily and is prone to cracking.

BONDED LEATHER VERSUS VINYL 
Polyvinyl chloride, popularly known as Vinyl or PVC is a faux leather which has been produced since the 1940’s by chemical companies like DuPont. It is used for shoes, car interiors and upholstery. Not as breathable as bonded leather, skin tends to stick to its surface, which makes it unpleasant seating in hot weather, it is easy to clean and maintain. Like bonded leather it cracks with use and is easy to puncture.

BONDED LEATHER VERSUS MICROFIBER 
A much more sophisticated form of faux leather: polyurethane resin and ultra- fine microfiber leather for automotive are combined to replicate the microscopic structure of leather. The complexity of its construction mean that it is more expensive than other faux products but it does have a number of advantages over bonded leather. It doesn’t scratch or tear and is non-fading. It breathes like real leather but it also has ant -bacteria and anti-mildew properties. Unlike bonded leather it is completely odourless.

BONDED LEATHER VERSUS REXINE 
Rexine is the registered trademark of a British artificial leather which has been produced since the 1920’s. Essentially a cloth backing is coated with cellulose nitrate and embossed to produce the illusion of leather. Primarily used for car interiors this is now regarded as retro faux leather and as such is sort out by collectors.

BONDED LEATHER VERSUS BICAST
Bicast is constructed using a split leather backing to which a layer of polyurethane is applied. The surface is then embossed to give the appearance of leather. It shares many of the qualities of bonded leather: it has a consistent texture and is easy to clean and maintain but it doesn’t breathe like leather and it lacks strength and durability.

BONDED LEATHER VERSUS LEATHERETTE 
Leatherette is a plastic based synthetic leather. Unlike bonded leather it does not scratch and it does not fade in sunlight. Like most faux leather, it does not breathe and is unpleasant next to the skin. Although it might be the preferred choice of those who don’t like to use animal products, it is made from non- biodegradable, non-renewable materials and is therefore considered less environmentally friendly.