knowleee

Enviar mensaje
Foto de perfil

  • Miembro desde: 06-01-22
  • Última vez online: 06-01-22

Anuncios

Bags of style: how the backpack became a fashion essential

Bags of style: how the backpack became a fashion essential

Descripción: Bags of style: how the backpack became a fashion essential     They used to be carried by the slightly awkward-looking kids in the school playground or hikers and were much more likely to be sported by men than women. But now, go to any high street, office or packed rush-hour bus and the humble backpack bag is everywhere.     Fashion searches for rucksacks are up 37% month-on-month, according to global fashion search platform Lyst. In the UK the annual amount spent on backpacks has risen every year since 2014 when, according to global market research company Euromonitor International, the retail spend was ￡112m – it forecasts the 2019 figure will be ￡219.5m.     “There has been an enormous change in attitudes towards day packs,” says Ralph White, UK managing director of the Swedish rucksack brand Fj?llr?ven.     According to Domitille Parent, product director at Eastpak, a brand that has been making rucksacks for over 40 years, an increasing number of commute backpack buyers are women: nearly 60% of online sales in the UK are made by women, and that number has been rising year-on-year. In the US, according to the market research firm NPD, sales of what they label women’s backpacks are up by 28% in the past year – with New York, Los Angeles and San Francisco the top three growth regions – while sales of men’s backpacks are down.     Of course, it should be no surprise that women are using a style of bag that is practical and – increasingly – stylish, too. But it has taken something of a shift in attitudes for the backpack to find mainstream traction in workplaces – and gender parity. As with many things, Miuccia Prada was a pioneer: when she released a nylon rucksack, made from military parachute fabric, in 1984, it was considered radical. All the other bags around were, she said in a recent interview with Vogue magazine, “so formal, so lady, so traditional”.     In the past, style blogger and backpack-wearer Susie Lau, aka Susie Bubble, has cited the Phoebe Philo effect. As former designer at Celine, Philo led the charge for what many brand “ugly” fashion, from Birkenstocks and clogs to backpacks.     Skipping forward to 2016, Burberry’s monogrammed backpacks were the elevated version that convinced the likes of Cara Delevingne to embrace the look. At the Tribeca film festival last year Sarah Jessica Parker, the woman to thank for sparking many an impractical tiny handbag trend, was spotted wearing a rucksack on the red carpet. On the Prada men’s AW19 catwalk they were worn by Gigi Hadid and Kaia Gerber, and Chanel’s 2020 Cruise show featured a outdoor backpack.     With many high-fashion brands, from Gucci to Coach, making rucksacks; the mid range of the market seeing a proliferation of more sophisticated designs – from the likes of Herschel to Dr Martens – and more than 400 styles offered on Asos, backpacks have come a long way from the days of Power Rangers or My Little Pony bags.     The rucksack’s fashion credentials have been bolstered by the rise of gorpcore – a neologism coined in 2017 from the acronym “gorp”, which stands for “granola, oats, raisins, peanuts”, aka trail mix, and encompasses all manner of camping attire. The ongoing popularity of luxury sportswear has helped make rucksacks less back-of-the-bus and more chia seeds and balasana. With the rise of the urban hiker look last year, the field trip look went high-fashion. “The outdoors as a whole has definitely got more fashionable,” says White. Plus it’s come into cities.     With some of the most popular brands hailing from Sweden, they play into our era’s love of all things Scandi. As White explains: “There has definitely been a rise in the popularity of Scandinavian culture – from hygge to fika. Fj?llr?ven takes a very Scandinavian approach to its product design.” Its now-iconic K?nken, was introduced as a bag for Swedish children in 1978.     The sheer practicality of the rucksack is a plus point, too. Backpacks are “easy to wear, hands-free, fuss-free and comfy,” says Georgie Tym, a lecturer at Cordwainers, the shoes and accessories brand of London College of Fashion. Function appears to be winning over any lingering competition from archaic, gendered double standards. If Danielle Drake, PR manager at Sandqvist, a high-end Swedish bag brand, is to be believed, the backpack is to bags what flats are to high heels. “The past pressure of having to cram all of your gear into a shoulder bag just for the sake of dated perceptions on women’s workplace attire has no place in today’s world.”     As we approach the end of the year in Singapore, we have a small favour to ask. We’d like to thank you for putting your trust in our journalism this year - and invite you to join the million-plus people in 180 countries who have recently taken the step to support us financially, keeping us open to all, and fiercely independent.     In 2021, this support sustained investigative work into offshore wealth, spyware, sexual harassment, labour abuse, environmental plunder, crony coronavirus contracts, and Big Tech.     The new year, like all new years, will hopefully herald a fresh sense of cautious optimism, and there is certainly much for us to focus on in 2022 - a volley of elections, myriad economic challenges, the next round in the struggle against the pandemic and a World Cup.     With no shareholders or billionaire owner, we can set our own agenda and provide trustworthy journalism that’s free from commercial and political influence, offering a counterweight to the spread of misinformation. When it’s never mattered more, we can investigate and challenge without fear or favour.     Unlike many other media organisations, Guardian journalism is available for everyone to read, regardless of what they can afford to pay. We do this because we believe in information equality. Greater numbers of people can keep track of global events, understand their impact on people and communities, and become inspired to take meaningful action.     If there were ever a time to join us, it is now. Every contribution, however big or small, powers our journalism and sustains our future. Support the Guardian from as little as $1 – it only takes a minute. If you can, please consider supporting us with a regular amount each month. Thank you.     Backpacks were once considered casual and suited only for travel or for students who needed to lug books by the kilos. It was a hard-working bag meant for the wearer’s comfort.     But as offices become more mobile with laptops and assorted gadgetry (chargers, tabs, power banks and mobile phones), a foldable backpack has become the goto workbag. Add to this the rise of a casual corporate culture, where athleisure is kosher at the workplace and sneakers are subbing in for high heels for women and dress shoes for men, and backpacks are strictly formal now.     Making and selling backpacks and travel bags — of burlap and vegan leather — is how Samriddh Burman, Karuna Parikh and Rewant Lokesh of Kolkata came together to start The Burlap People.     Parikh says each of them chose backpacks as their daily work or office bags and the backpacks came naturally to them.      Backpack loads of school students during school days have been suggested to range from 10% to as high as 25% of their body weight and may have a negative impact on their body. The aim of this review was to identify and review studies that have examined impacts of contemporary backpack loads on school children. Methods: A systematic search was conducted of the literature using key search terms. After relevant studies published in recent years were selected using strict inclusion and exclusion criteria, the studies were critically appraised and relevant data were extracted and tabulated prior to conducting a critical narrative synthesis of findings. Results: Twenty-one studies were included, ranging in methodological quality from poor to good (critical appraisal scores 22% to 77%). Students carried on average over 15% of their own body weight, which caused biomechanical and physiological adaptations that could increase musculoskeletal injury risk, fatigue, redness, swelling and discomfort. Conclusion: Considering the limited methodological quality and variations in foci across studies, further research is needed to elucidate: (1) the loads students carry around on a school day in their school backpacks and; (2) the biomechanical, physiological and physical effects of load carriage on students.     A review by Mackenzie et al. in 2003 of drawstring backpack loads carried by school students during a school day identified that children were carrying as much as 30% to 40% of their body weight. This review, while acknowledging that no critical maximal load had been established (to address back pain), recommended around 10% of the child’s bodyweight as a maximum limit. The following year, a review by Brackley and Stevenson stated that the majority of work considered the loads carried by children to be above recommended limits, likewise recommending a maximal load of between 10 to 15% of the child’s bodyweight. Since these reviews, more recent research has suggested that these loads are lighter and in some instances may be meeting this recommendation, with loads ranging from 10% to 25% of the school child’s bodyweight. However, this recent research, in agreement with the earlier reviews, also suggests that these loads have a negative impact (e.g., increased forward lean, pain, skin pressure) on children’s bodies .

Fecha de Publicación: 06-01-22

The Effect of a Wrist Brace on Injury Patterns

The Effect of a Wrist Brace on Injury Patterns

Descripción: The Effect of a Wrist Brace on Injury Patterns     We compared patterns of bony and ligamentous injury with distal radial fractures in braced and unbraced wrists using 20 paired fresh cadaveric upper extremi ties. A commercially available wrist brace was placed on one wrist in each pair. Specimens were then placed in a fast-loading gravity-driven device and subjected to loads averaging 16 kg from an average height of 78 cm. Postfracture radiographs were obtained, the spec imens were dissected, and fracture patterns and liga mentous integrity were assessed. The following frac ture types were produced: distal radial fractures (eight unbraced, seven braced) and intraarticular (seven un braced, four braced). Radiographically, seven un braced wrists demonstrated carpal bone fracture and one braced wrist demonstrated carpal fractures. Eight unbraced and three braced wrists sustained carpal intrinsic ligament injuries, four unbraced and one braced wrists demonstrated extrinsic ligament injuries. More capsular tears occurred in the unbraced group (N = 8) than in the braced group (N = 1). This model demonstrated a difference in the patterns of injury in unbraced and braced wrists subjected to the same mechanical conditions, which suggests that use of a wrist brace may alter patterns of wrist injury.     Braces and splints can be useful for acute injuries, chronic conditions, and the prevention of injury. There is good evidence to support the use of some braces and splints; others are used because of subjective reports from patients, relatively low cost, and few adverse effects, despite limited data on their effectiveness. The unloader (valgus) knee brace is recommended for pain reduction in patients with osteoarthritis of the medial compartment of the knee. Use of the patellar brace for patellofemoral pain syndrome is neither recommended nor discouraged because good evidence for its effectiveness is lacking. A knee immobilizer may be used for a limited number of acute traumatic knee injuries. Functional ankle braces are recommended rather than immobilization for the treatment of acute ankle sprains, and semirigid ankle braces decrease the risk of future ankle sprains in patients with a history of ankle sprain. A neutral wrist splint worn full-time improves symptoms of carpal tunnel syndrome. Close follow-up after bracing or splinting is essential to ensure proper fit and use. Am Fam Physician 2007;75:342–8. Copyright ? 2007 American Academy of Family Physicians.)     Family physicians often must make decisions regarding the use of braces or splints in the management of musculoskeletal disorders. Bracing can be useful for acute injuries, and also for chronic conditions and in the prevention of injury. The purpose of braces and splints is to improve physical function, slow disease progression, and diminish pain. They can be used to immobilize an unstable joint or fracture, to unload a portion of a joint and improve pain and function, to eliminate range of motion in one direction, or to modify range of motion in one or more directions. They do not replace a good rehabilitative program, and the entire spectrum of treatment options should be explored and used as needed.     Accurate diagnosis of the injury is important in determining whether a brace or splint is indicated. Generally, splints are for short-term use. Excessive, continuous use of a brace or splint can lead to chronic pain and stiffness of a joint or to muscle weakness. However, long-term use of some braces, such as a knee support, can help prevent progression of pain attributable to osteoarthritis of the knee.     Given the limited evidence on the use of braces and splints, it is particularly important to use a patient-centered approach, with consideration for individual patient's expectations and concerns and an understanding of the nature of their activity. For example, for high school and collegiate athletes, there are specific rules on the types of protective equipment, splints, and braces that may be worn during competition.1 Close follow-up after bracing or splinting is essential to ensure proper fit and use.     The most common types of braces and splints used in primary care and the quality of evidence to support current recommendations are discussed in the following.     Relatively few studies on bracing have been published, and most are not randomized controlled trials. A Cochrane systematic review4 identified only one randomized controlled trial.2 In this study, 119 patients who had osteoarthritis associated with varus deformity of the knee were randomized to receive usual treatment, unloader knee brace, or neoprene sleeve to evaluate the effect of these therapies on functional status and quality of life.2 Although both the sleeve and the brace reduced pain and improved function, greater benefit was found with the unloader brace. In a randomized crossover trial, 12 patients with varus osteoarthritis were given a simple hinged brace or an unloader brace during two six-month periods. Because patients acted as their own controls, it was possible to identify statistically and clinically significant benefits for the unloader brace that were greater than those of the hinged brace despite the small number of patients involved in the study.5 The American Academy of Orthopaedic Surgeons recommends unloader braces for the reduction of pain in patients with osteoarthritis of the knee.6 This conservative option is thought to extend the time before patients need to undergo knee arthroplasty; it also can be considered for those who are not candidates for surgery.     ANTERIOR KNEE PAIN BRACE     Anterior knee pain, also called patellofemoral pain syndrome (PFPS), is a common complaint among young, active patients. Its etiology is multifactorial and controversial, and the treatment can be frustrating for the physician and the patient. Braces have been developed to address the most commonly accepted etiology: malalignment of the patellofemoral joint. Typically, these braces are made of neoprene or a similar elastic material, with additional straps or a buttress for patellar support. The buttress can be circular, C-shaped, J-shaped, or H-shaped to help maintain tracking of the patella in the femoral groove. These braces are reasonably priced, and off-the-shelf models are adequate (Figure 2).     Evidence of the effectiveness of braces for treatment or prevention of PFPS is limited because of methodologic differences and shortcomings across studies. Two systematic reviews published in 2002 and 2003 concluded that, because of the low quality of available studies, there is insufficient evidence to support or to discourage the use of patellar bracing for PFPS.7,8 Likewise, an American Academy of Pediatricians technical report stated that there is no scientific evidence to support the use of knee sleeves.     Two studies, published after the systematic reviews, produced contradictory results.10,11 In one small, anatomic study using magnetic resonance imaging, researchers examined patellar alignment, patellofemoral joint contact area, and pain response in patients with and those without bracing.10 They found significant changes in contact area and improvement in pain in the braced group but little change in patellar alignment. In a prospective randomized clinical trial published in 2005, researchers randomized 136 patients with anterior knee pain to treatment with home exercises, patellar bracing, exercises plus bracing, or exercises plus knee sleeve, and found no difference in pain ratings between the four groups after 12 weeks.11 Small studies on military recruits have reported a decrease in the incidence of anterior knee pad with patellar bracing.12,13     Because of the limited data and lack of clear recommendations and consensus on the effectiveness of patellar braces for the treatment or prevention of anterior knee pain, decisions regarding their use must be made on an individual basis. Some patients may feel benefits; therefore, patients should be told that study results are inconclusive or mixed. A therapeutic trial of braces may be worthwhile because the braces are not expensive and no harmful effects have been found. Nonetheless, a brace is no substitute for a good rehabilitative program that includes strengthening, range-of-motion, and proprioceptive exercises.14–17     KNEE IMMOBILIZER     Complete immobilization of the knee for an extended period is generally contraindicated because of the prolonged stiffness, muscle atrophy, and chronic pain that result. However, there are exceptions. Indications for the use of a knee immobilizer (Figure 3) include the acute (or presurgical) management of quadriceps rupture, patellar tendon rupture, medial collateral ligament rupture, patellar fracture or dislocation, and a limited number of other acute traumatic knee injuries. The duration of immobilization and management of these conditions is variable and beyond the scope of this article.     Other knee braces include prophylactic braces designed to prevent or limit the severity of knee injuries. These braces are used commonly by football players to help protect against medial collateral ligament injury. Functional knee braces are designed to provide stability to a ligament-deficient knee (e.g., in a patient with an anterior cruciate ligament tear before surgery) and also can be used for postsurgical repair. Rehabilitative knee sleeve are used postoperatively to allow protected range of motion.6 Recommendations for the proper selection and use of these braces are highly variable, complex, and often inconsistent; the choice seems to be based on anecdotal experience and trial and error.     Ankle Braces     Ankle sprains are one of the most common acute musculoskeletal injuries. The treatment of lateral ankle sprains can be confusing because of the many braces and splints that are available for this injury. Ankle braces can be divided into two categories: rigid and functional. Rigid braces essentially immobilize the entire ankle. Functional braces, which include semirigid (e.g., Aircast) and soft, lace-up braces, allow some plantar and dorsiflexion at the ankle while controlling for inversion and eversion. Semirigid braces are made of thermoplastic contoured lateral stirrups lined with air-filled foam pads for support of the medial and lateral malleoli. Supplemental air can be added to these air cells through an inlet port.18 Soft, lace-up braces are usually made of canvas. Semirigid stirrup braces restrict ankle inversion and eversion more than lace-up braces19 (Figures 4 and 5). External ankle support also has been shown to improve proprioception, an important component in the reduction of recurrent ankle sprains.     Complete immobilization of the ankle following an acute ankle sprain is no longer recommended. Early mobilization using functional treatment is preferred.20 A Cochrane systematic review concluded that treatment of acute ankle sprains with functional braces leads to better outcomes (e.g., shorter time taken to return to work or sport, less swelling and instability, greater overall satisfaction) compared with immobilization.21     A systematic review identified nine randomized trials that compared different functional treatment strategies (e.g., lace-up or semirigid brace, elastic bandage) for acute lateral ankle ligament injuries.20 Because of the variety of treatments and inconsistently reported follow-up times, the most effective functional treatment brace could not be identified. However, lace-up ankle braces more effectively reduced short-term swelling than did semirigid ankle braces. The most recent randomized controlled study, published in 2005, demonstrated improvement in ankle joint function after a moderate to severe inversion injury using a semirigid (Aircast) brace.18 Thus, the evidence supports a functional treatment approach to inversion ankle sprains with the use of a semirigid or soft, lace-up brace.     PROPHYLACTIC ANKLE BRACES     Multiple studies have evaluated the effectiveness of ankle braces for the prevention of ankle sprains. There is good evidence that semirigid braces help to prevent ankle sprains during high-risk sports such as soccer and basketball. According to a Cochrane systematic review, patients with a history of ankle sprain can be advised that wearing such a brace reduces their risk of future ankle sprains.22     Few studies recommend the duration for which wrist brace should be used. However, one systematic review on the prevention of ankle sprains in sports recommends that patients who sustain moderate or severe ankle sprains should wear an ankle brace during sports activity for at least six months following the injury.23     Wrist splints     Carpal tunnel syndrome is a common compression neuropathy, often treated initially with a splint to relieve pressure on the median nerve. Few recent studies have addressed the effectiveness of wrist splints in the treatment of carpal tunnel syndrome, and no randomized controlled trials have compared wrist splinting with no treatment. One systematic review concluded that there is limited evidence to support the use of splinting for up to six months,24 whereas a second review found that a hand brace improved symptoms and function after four weeks.25     There are various options when prescribing a wrist splint, including neutral versus cock-up (extension) splints, nighttime versus full-time wear, duration of wear, and custom versus prefabricated splints. One prospective study found that neutral splints relieved symptoms more than cock-up splints (20 degrees of extension).26 The authors also found that symptom relief was evident in the first two weeks of wearing the splint; no additional improvement was noted between weeks 2 and 8 of wear.26 The first long-term prospective randomized study to compare nighttime splint wear with steroid injection found improvements in symptoms as well as motor and sensory nerve conduction velocities after one year of wearing a splint at night.27 Another randomized clinical trial, comparing symptoms and functional deficits in nighttime versus full-time splint wear, found the most significant improvements at six-week follow-up in the group instructed to wear the splints full-time.28     Splints come with a dorsal or volar compartment in which metal or thermoplastic inserts can be placed. It is easier to mold a custom insert than it is to mold a prefabricated metal one29 (Figure 6). When fitting a prefabricated wrist splint, it is important to observe the wrist position, because off-the-shelf wrist splints may have significant extension. Prefabricated splints, which tend to be more rigid and less comfortable than thermoplastic custom splints, typically are made to have 10 to 30 degrees of extension. Patients wearing prefabricated splints should return with the splint so that the angle can be adjusted to the neutral position if necessary. Researchers suggest that prefabricated splints must be adjusted to the neutral position in patients with carpal tunnel syndrome.

Fecha de Publicación: 06-01-22

Acrylic Nails: Everything You’ve Ever Wanted to Know

Acrylic Nails: Everything You’ve Ever Wanted to Know

Descripción: Acrylic Nails: Everything You’ve Ever Wanted to Know     Acrylic nails are the definition of glamour in the beauty world, and pretty much anyone with eyes can see that. But are fake nails safe? Do acrylic nails hurt? How much do acrylic nails cost? And what are acrylic nails even made of, anyway? If you’re curious about acrylics and have never tried them before, it’s totally understandable if you have some reservations about the beauty treatment. Find out if acrylic nails are right for you after reading our answers to all your questions about the unique manicure below, and then get inspired by some of the prettiest acrylic nails on the internet today.     Acrylic nails are nail enhancements made by combining a liquid acrylic product with a powdered acrylic product, according to Nails magazine. The two products (known as a monomer and a polymer, respectively) together form a soft ball that can be fashioned into a nail shape. Once a nail technician applies this acrylic to a client’s nails, the material hardens and becomes much stronger. And then it can be buffed and filed to the customer’s liking.     But wait: Who invented acrylic nails? You might be surprised to learn that acrylics as we know them today were first developed in 1934 by a dentist named Maxwell Lappe. He created these artificial nails in order to help nail-biters curb their habit. Who would’ve guessed that they’d become such a huge fashion statement in the decades following? Considering the fact that chemists have developed much better techniques to make acrylic nails look more natural, it’s no surprise that this beauty treatment still has such an enormous staying power to this day.     How to Remove Acrylic Nails at Home      It is highly recommended to go back to the nail technician or salon where you got your long coffin fake nails done to have them removed. After all, the professionals are the ones that are most experienced in knowing exactly how to soak off acrylic nails and file them down in an efficient manner. However, sometimes going to the salon right away isn’t possible and you absolutely need to know how to remove acrylic nails at home for one reason or another. (Hey, life happens!) If you must learn how to take off acrylic nails at home, you want to be sure you do it safely: Beauty experts at Makeup.com say your best move is to soak your nails into acetone until they’re totally soft and then file the acrylics off one by one. As you can imagine, these instructions about how to get acrylic nails off can take quite a bit of time to complete in real life. But it’s a much better method of removing acrylic nails than trying to pull them off manually. Overall, trying to learn how to remove acrylic nails without acetone or a file is a pretty bad idea. If you try to do that — especially while your acrylics are still hard — you can say hello to some seriously brittle and weak natural nails in the future. No one wants that!     How are acrylic nails applied?     After you choose your preferred nail shape, length, and color, your technician should begin your acrylics appointment by cleaning, soaking, and filing your natural nails. If you requested length to be added to your nails, they’ll add artificial tips after that. (If you requested very short acrylic nails, they will skip this step.) Next, nail techs will apply an adhesive before attaching the acrylic nails to all your nail beds. Then, they sand down and shape the acrylics. Finally, they add any additional polish, accessories, or nail art that you asked for at the beginning of the appointment.     If you’re wondering how to apply acrylic nails at home, this can vary depending on what type you’re using. Luckily most kits, such as Kiss Products Salon Acrylic French Nail Kit ($6.49, Amazon), include instructions about how to do acrylic nails safely and effectively on your own.     Gel Nails vs. Acrylic Nails: Should I get acrylic nails?     If you’re considering getting acrylic nails, you’ve probably heard some folks suggest that you try gel nails instead. Considering that gel nails are often grouped in the same type of beauty treatment as acrylic nails, it’s easy to confuse the two, or even mistake them as terms that could be used interchangeably. In reality, they’re quite a bit different — and they both have pros and cons.     While acrylics are nail enhancements made by combining a liquid acrylic product with a powdered acrylic product, gel nails are part of a more homogenous gel product that needs to be “cured” or “sealed” onto the nail with the use of a UV light between each layer. According to Nails, a helpful way to understand the difference between gel and medium coffin fake nails is to think of gel as premixed acrylic.     While acrylic nails are more strong and durable than gel nails, gel can actually be used to strengthen the natural nail and helps protect it as it grows. That said, acrylic nails are a bit easier for you to maintain at home, because you can both fix them soak them off without the help of a nail technician, unlike most gel nails. However, gel nails may be a more practical choice for people who use their hands quite a bit; they are far more flexible than acrylics. Gel is generally pretty odorless, and the same cannot be said for acrylics.      Wondering, “Should I get acrylic nails or gels?” When it comes to the debate about gel nails vs acrylic nails, there’s not really a way to say which one is the actual “winner.” At the end of the day, it’s totally up to you whether you want to opt for acrylic nails or gel nails — it’s all personal preference about which method works best for you and your lifestyle. Goodness knows that both beauty treatments boast a wide variety of fans, and either group would be more than happy to have you join them for the fun.     How much do acrylic nails cost?     The price of acrylic nails varies widely between nail technicians. According to Cost Helper Health, the typical cost for a mid-range acrylic manicure at a spa or salon ranges from $35 to $45 for a standard set. For colors like pink or white, that price can increase to $50 or $60. But how much are acrylic nails that feature an elaborate design? Don’t be shocked when you see that especially creative acrylic nails can cost up to $100 or even $120. For example, if you’re getting fancy coffin acrylic nails or holiday-themed acrylic nails, you can expect to pay a premium price. Remember: It might be tempting to pay a low price for acrylics, especially since there are “deals” of prices as low as $10 floating around out there. But when it comes to your nails — and everywhere else on your body — your health comes first. And there’s a much higher risk of your nails suffering in the long run from a low-quality acrylic set. Not worth it!     How long do acrylic nails last?     The lifespan of acrylic nails varies widely from person to person. For example, if someone uses his or her hands for work quite a bit — especially for manual labor — that person might learn pretty quickly that acrylic nails won’t last too long compared to someone who uses their hands for little more than typing. But how long do acrylic nails last in a general sense? Experts say you need to return to the salon every two to three weeks to fill in the gaps that appear as your natural nails grow. So that’s a good rule of thumb (and all the rest of your fingers!) to follow for how long you can expect your short coffin fake nails to look fabulous. But how often should acrylic nails be replaced? If you love wearing acrylic nails often, it might be worth considering removing them every two to three months to let them “breathe” in between sets.     Are acrylic nails safe?      In a piece for Mayo Clinic, dermatologist Lawrence E. Gibson, MD, says that artificial nails are unlikely to harm natural nails — as long as they’re healthy. That said, it is possible to encounter some problems if you’re not careful while maintaining them. If your artificial nail is damaged or if you let your nails grow too long, a gap can develop between your acrylic and your actual nail. The warm and moist environment there is basically a breeding ground for an icky infection. An infection might also happen if you request very long or rigid acrylics. Of course, if your technician uses unsanitary tools, this will put you more at risk for an adverse reactions (as is the case with just about every beauty treatment out there).     Luckily, there are ways for fans of acrylic nails to keep themselves as safe as possible. Other than making sure that your nail technician properly sterilizes all tools used during the treatment, it’s also a good idea to select salons that display a current license and technicians who are licensed by the state board. For optimum safety, request a new nail file or bring your own (nail files cannot be sterilized like other nail tools). If you spot signs of a nail infection — such as redness, swelling, and pus — talk to a trusted medical professional about the best treatment for you.     Why do acrylic nails hurt the first day?     According to licensed nail technicians, there are a few possible reasons why your acrylic nails might be hurting right after you get them done. For instance, the nail technician might have applied a tip that was too small for your nails. Maybe they accidentally pinched the nail during the application. Or perhaps your nail might have been over-filed. Although this can happen every now and then, it’s not a good sign if your acrylic nails hurt every single time you get them done. If you’re still wondering, “Why do acrylic nails hurt?” a day after your appointment, it might be time to find a different technician for the job.     Are acrylic nails vegan?     If you’re a strict vegan, acrylic nails might not be the best choice for you. According to The Beauty Academy, the brushes often used for stiletto fake nails are typically made from “kolinsky,” which is sometimes called sable hair. This kolinsky is real hair gathered from an animal — a type of weasel found in particularly cold places in Russia and China, to be specific. This natural hair from the weasel is the preferred brush option for many technicians because it has a certain thickness to it that helps it hold the acrylic liquid effectively. It’s also quite strong and flexible.     That said, it’s worth noting that some technicians are starting to use synthetic bristles in their brushes for acrylics. As with technology in general, this “vegan” method is improving. But many nail technicians still prefer the brushes made with natural hair instead. If you’re not sure which type of brush — or which type of nail products in general — that your technician uses, always ask first. You might be surprised!     Do acrylic nails damage your nails?     According to Thomas Knackstedt, MD, of Cleveland Clinic, most folks can use acrylic nails without it affecting the overall health of the natural nails. However, it is possible that some people can develop a contact allergy to dyes or glues used during the appointment. But if you don’t get a reaction after the treatment, do acrylic nails damage your nails after you get them removed? As is the case with many beauty treatments, the part of the process that can actually be the most irritating is the removal of acrylic nails. If you take good care of your nails and keep them in generally good health, the irritation should be fairly minimal. That said, a few people might notice that their nails are particularly sensitive afterward and visibly brittle or discolored. If you’re part of that population, you may want to consider alternate options for your next manicure. But if not, feel free to get those bad boys glued on — especially if you have a special occasion coming up where it’s time to impress.     Scroll below to see some of the most stunning types of acrylic nails out there, then click on a circular button below your favorite image to share it instantly with family and friends on Facebook, Twitter, or Pinterest!     Coffin nails are a great way to add some edge to your mani when go-to shapes like square and almond just aren't cutting it. Coffin fall nails are even better when spooky season hits. Don't let the eerie name put you off—this shape is fierce and fun.     If you're into the technical stuff, let's start off with the basics: What are coffin nails? “Traditionally coffin shaped nails are longer nails that have a square or straight top and often taper slight towards the tip," explains Emily Rudman, founder of Emilie Heathe. “Another popular shape is the ballerina which is a longer coffin shape—often the two are used interchangeably.”      For those who want to give their fingers a more elongated shape as the leaves start to fall, coffin fall nail designs are a great option. The length is guaranteed to make a beauty statement, and the right autumn nail designs won't leave you feeling like you're cosplaying a pumpkin spice latte.      And for years, longer nails have been used as a tool for creative expression and personal style, explains Rudman. “The longer the almond fake nails, the more of a canvas one has to work with. From a cultural standpoint, many of the trends we see in nails comes from Black, Asian, and Latinx cultures. And with those cultures in America making more of a statement while taking ownership of their contributions to society, those styles have also become more popularized.”     Artists like Cardi B have been adorning their hands with extensions way before the fame and have continued to showcase new styles, while also helping put the people behind their eye-catching work on the map. Jenny Bui, the long-time nail artist responsible for many of Cardi and sister Hennessy's  blinged-out manis is known for dazzling extensions drenched in technicolor Swarovski crystals.      But while long nails seem to be everywhere, as seen on celebrities from Kylie Jenner to Dua Lipa, that wasn't always the case. In fact, not too long ago “claws” weren't a compliment. “There is also always appropriation, in this case, traditionally longer nails were viewed as ‘inappropriate’ or 'not classy,” says Rudman. "But as the world has shifted and as white cultures have accepted these beauty trends, it has lead to wider acceptance amongst the majority. It’s neither OK or fair, but it often happens this way." As beauty continues to evolve it's important to keep in mind the history of how the latest trends came to be to give credit where it's due.      A marker for showcasing your personality while also adorning yourself, coffin nails are here to stay. If you've decided to swap out your go-to shape to give it a spin but are looking for some fall acrylic nails inspiration, read on. From jeweled tips to a classic french with a tropical twist, we've rounded up 10 of the cutest coffin fall nails to bookmark for your next salon visit. 

Fecha de Publicación: 06-01-22

Water Well Maintenance and Rehabilitation

Water Well Maintenance and Rehabilitation

Descripción: Water Well Maintenance and Rehabilitation     The purpose of the study to obtained water well screens opening size and gravel packs size, and to access within the groundwater inter through the aquifer to the well screen and prevent running sand from entering the well. The use of properly designed screen and gravels are important and this paper is an important reference for the design of groundwater wells. In this study, the purpose of the circle method is to design water well and the benefits of sand control. The determination of screen slot size and its variation in the opening is often a major aim of hydrogeological studies. However, measurement of hydraulic conductivity (K) at a high spatial resolution in sedimentary aquifers is a challenge. One commonly used approach is to estimate slot size from grain size analysis. The objectives of this study are to compare between curve of grain size analysis, bar graph and circle method used applied different formulas for the determination of slot size from grain-size data and to evaluate how well this method predicts slot size and gravel pack. Correlation between the mechanical analysis curve, bar graph and the circle methods were found for the used applied different formulas. Based on circle results, the applied circle formulas appear to be suitable for an initial assessment of aquifer properties. However, considering the difference in calculated aquifer parameter values, results are smaller significantly and reliable for the high analysis of aquifer materials.     The well screen is the component of a well which provides an opening through which water enters the well casing from the aquifer, as well as stabilizing the material in the “near-well zone” and preventing it from entering the well. Screens may be constructed with a variety of different materials and designs, as appropriate to the design of the well and its aquifers. Typical types of screen are:     Horizontal bridge slot screen, a pipe-based well screen with punch-formed downward facing louver-shaped openings.     Continuous wire wrap screens, manufactured by wrapping shaped wire around an internal array of rods.     Bridge slot screens, produced by rolling and welding perforated steel plates or sheets.     Machine-slotted (milled) screens, manufactured by milling casing with axially oriented precision cutters.     Well casing perforated in place with a mills knife or a hydraulic perforator lowered down the cased borehole.     Different wedge wire screen may by evaluated for a particular well design based on the material, size of perforations, percent of open area, cost, susceptibility to corrosion, and collapse strength. A properly designed screen allows sand-free water to flow into the well with a minimum drawdown.     As a water well ages, the rate at which water may be pumped (commonly referred to as the well yield, flow or performance) tends to decrease, especially in wells that were not properly developed when first drilled. This fact sheet briefly describes common well problems and discusses prevention and rehabilitation measures.     Water Well Maintenance     Water wells require regular maintenance to ensure adequate water flow and continued drinking water safety. To ensure water quality, well water should be tested annually for total coliform bacteria and E. coli bacteria by a state accredited testing laboratory.     Every three years, additional testing is recommended for pH and total dissolved solids as well as tests related to land uses occurring or expected to occur within sight of the well. Additionally, if there are obvious stains, tastes, or odors in water, seek testing that will help identify the source of these symptoms.     Water wells should also be inspected annually for obvious signs of damage or contamination. Be sure the area within 100 feet around the continuous slot screen is clear of debris or items that might pollute the water supply.     Get the well professionally inspected by a water well contractor every ten years. Keep all records related to the water well including:     Water well completion report or log (if you have it) which should include information such as water well depth, date drilled, construction (including casing specifications, grouting and screen), and water well yield or flow rate in gallons per minute (gpm)     Water quality test reports     Past inspection reports     Invoices from work done by water well contractors (including pump replacement)     Water treatment equipment warranties, invoices and manuals     To find some of this information you can check with the Pennsylvania Department of Conservation and Natural Resources (PA DCNR) Pennsylvania Groundwater Information System (PaGWIS) or contact a local well driller.     Well Performance     As a water well ages, the rate at which water may be pumped (commonly referred to as the well yield, flow or performance) tends to decrease, especially in wells that were not properly developed when first drilled. A drop or complete loss of water production from a well can sometimes occur even in relatively new wells due to a lowered water level from persistent drought or over-pumping of the well which can dewater the water-bearing zones. More often, reduced well yield over time can be related to changes in the water well itself including:     Incrustation from mineral deposits     Bio-fouling by the growth of microorganisms     Physical plugging of "aquifer" (the saturated layer of sand, gravel, or rock through which water is transmitted) by sediment     Sand pumping     Well screen or casing corrosion     Pump damage     This fact sheet briefly describes these common problems and discusses alternative prevention and rehabilitation measures.     Water Well Rehabilitation     Measures taken to correct these problems are referred to as well rehabilitation or restoration. A successful well rehabilitation will maximize the flow of water from the well. The chances for successful rehabilitation are dependent on the cause(s) of poor well performance and the degree to which the problem has progressed.     Upon noticing loss of performance in your well have a professional water well contractor inspect your well, preferably with a downhole camera.     A common measure of the delivery of water by a water well is referred to as the "specific capacity" which is defined as the pumping rate (gallons per minute) divided by the drawdown or increased depth to water during pumping (in feet).     Generally, a decrease of 25% or more in well yield indicates that rehabilitation is in order. Delaying rehabilitation procedures can significantly increase costs and in some cases make rehabilitation impossible.     To detect deterioration of well performance, you must have a point of reference. Often this reference is the original well construction and pump test data which are normally supplied to you by the well driller on a well completion report or well log when the well is installed. However, even if you do not have this information, significant changes in your well are also a warning sign.      The principal means used for rehabilitation of chemical incrustation problems involves the use of strong acid solutions to dissolve incrusting materials.     Once loosened or dissolved, the incrusting materials are pumped from the well with the acid solution for disposal.     The type of acid to be used, its form (liquid, granular, pelletized), the procedures used to introduce and agitate the acid solution, and the severity of incrustation all play a part in determining the success of acid treatment. It is common for acid-treated older wells to completely recover or even exceed the original well yield assuming any material dislodged by the acid is removed from the pre-packed well screen.     While acid treatment methods for incrustation removal are very effective, mechanical methods, such as wire brushing or scraping, are often used in conjunction with acid treatment to improve results.     A less common mechanical approach is the use of controlled blasting. Controlled blasting involves the use of explosives, carefully set at specific locations in the well bore, to fracture consolidated rock aquifer and incrusting materials. Experience has shown this technique, when done properly, to be useful for temporary well yield improvement. However, cracks opened by blasting often eventually become incrusted and additional rehabilitation measures are required to maintain well productivity.     Rapid growth of these bacteria can quickly clog well screen pores and render a well virtually useless in a matter of months. Once iron bacteria become established in a well, they are extremely difficult to eradicate.     Treating iron bacteria colonies in water wells is often a perpetual process that seeks to maintain well performance at an acceptable level. In general, chemical means of control are most effective. However, best results are achieved when chemical bactericides are used in conjunction with physical agitation of the well bore water to remove the biological residue.     The chemical of choice for most small diameter wells is chlorine. It has the advantage of being readily available, inexpensive, and is generally accepted by health officials for use in potable water supplies. For general disinfection purposes following routine well and piping construction, repair, or pump installation, a 50 mg/L dose of free chlorine is recommended. For treatment of severe iron bacteria problems concentrations as high as 500 to 2,000 mg/L are used.     However, chlorine treatment of iron bacteria problems may not be effective without subsequent agitation of the well water. Turbulent flow causes greater surface area exposure of slime growths to the chlorine solution and assists in dislodging obstructions.     For more information on how to shock chlorinate a well, consult our fact sheet Shock Chlorination of Wells and Springs  or contract with a professional well driller.     Since precipitation of iron in the bacteria biomatting contributes to clogging of flow spaces, rehabilitation results are usually improved when acid treatments are alternated with bactericide treatments.     The most important preventative measure to avoid physical plugging is proper well development. Adequate well development will stabilize the aquifer material so that subsequent pumping from the well will not result in excessive sediment removal. Removal of fine silt and clay particles introduced in some drilling fluids, or which naturally occur in certain kinds of aquifers, can only be accomplished with the use of chemical treatments.     As with other chemical rehabilitation treatments, agitation of the chemical into and out of the aquifer formation is crucial to success of the operation. This agitation may be provided by a surge plunger, compressed air, well pump, or high-velocity jet.     Use of a high-velocity jet is generally recognized as the most effective means of agitation. When water from the well is re-circulated for jetting, sediment should be removed prior to reuse. Continuous removal of dislodged sediment, as done in a re-circulating jet operation, gives the best results as the cleaning solution is able to penetrate more deeply into the aquifer medium.

Fecha de Publicación: 06-01-22

Introduction of the components of the film blowing machine

Introduction of the components of the film blowing machine

Descripción: Introduction of the components of the film blowing machine     Blow Membrane is a plastic processing method, which refers to a plastic processing technology in which plastic particles are heated and melted and then blown into a film. Usually, the polymer is extruded to form a tubular film blank, which flows in a better melt flow. In the state, the tube film is blown to the required thickness by high-pressure air, and it becomes a film after being cooled and shaped. The quality of the film material blown by this process is related to the film blowing machine and plastic particles. Film blowing machine is a machine that heats and blows plastic particles into plastic film. The film blowing machine has the advantages of simple structure, low investment, and quick product effect; high mechanical properties of the film; no edge material and less waste; the film product is cylindrical and the bag-making process is simple; it can produce a wide film.      The separation type screw divides the melting section into a solid bed and a melt bed. The width and depth of the solid bed gradually become smaller, and the width and depth of the melt bed gradually become larger, and finally become the width and depth of the metering section.     1. Feed zone.The volume of the screw groove in the feeding section remains unchanged. The material is in a solid state, and the main purpose is to transport the material forward as soon as possible.     2. Melting zone. The volume of the screw groove in the compression section gradually decreases. The material changes from solid to molten. The main purpose of the material is to change from solid to molten.     3. Melt pumping zone.The volume of the screw groove in the metering section remains unchanged. The material is completely in a molten state, and the main purpose is to make the material fully plasticized and send the material to the machine head at a fixed amount and pressure.     The cooling method of PE Blown Film Machine can be divided into two types: external cooling and internal cooling.         1. The external cooling method is the earliest application method. Under the action of the cooling ring, cooling air is released from a circular ring along the extrusion direction and the outer surface of the bubble to generate uniform cooling air around the ring. Inside the cooling ring, the air at the upper port is discharged at a faster average speed than that on the lower port. It is ensured that the shape of the film bubble is consistent with that of the air cooling ring, so that the average flow velocity of the air increases and thus the heat transfer is improved.          2. The internal cooling directly dissipates heat through the film bubble for cooling purposes. Because the flow rate of the air in the bubble is relatively low and has no regularity, external cooling is more widely used in the market. In the blowing process of the film blowing machine, in order to ensure the quality of the film product, the stability of the film bubble before the film is formed must be considered in order to effectively control the product qualification rate. The output of blown film of the film blowing machine is not only restricted by the film bubble, but also the cooling system of the film blowing machine. A complete cooling system can help the PE Film Blowing Machine work and run rationally.     With the rapid development of industrial technology, the film blowing machine has mastered the skilled production process, but compared with the more advanced technology level in foreign countries, there are still some gaps in some aspects, in order to obtain the development of the film blowing machine. In order to enter the international market, we must let the film blowing machine develop in a new direction.     A special plastic wrap blown by the film blowing machine, using advanced technology to make fruits and vegetables durable. The cling film is composed of a transparent film of a nylon semi-packaging machine. The film is nearly transparent and has good water permeability. A certain amount of sand syrup is placed in the interlayer to gently wrap the surface of the article. The film must be environmentally friendly. It is harmless and has strong water permeability. It can absorb fruit and vegetable juice to achieve fresh-keeping purpose. This special raw material requires high-end traction and drawing ability of the ABA Film Blowing Machine to ensure the toughness and breathability of the product film. Food packaging is the most used film. In the field, the high-grade film blown out by the film blowing machine can be used as a commodity packaging promotion to enhance commercial value.     At present, the popular packaging on the market is mainly plastic and paper. The blow molding industry mainly based on plastic blown film machine has a large proportion in the market, but with the stricter requirements on the paper industry, the new environmental protection and energy saving The indicators have raised the threshold for the paper industry, resulting in an increase in the cost of the paper packaging market and rising prices. This has led to a corresponding increase in the market share of plastic packaging, stimulating the development of the film blowing machine manufacturing machinery industry, while environmental protection and energy saving technology has been paid attention to in the film blowing machine machinery industry, promoting the blown film machine to the high level.     In the future, as technology continues to deepen, the film blowing machine will continue to be upgraded and will play a more important role in promoting the plastics and packaging industry to the high end. China is a large manufacturing country with an advantage in scale. However, in the research and development and commissioning of high-end equipment, domestic plastic machines have not yet reached the international level. Domestic blown film machine relies on huge consumer groups, and the market prospect is promising, but the development towards high-end is the development trend that blown film machines must face.     Film blowing machine blown out of the film is usually used for goods transport, food packaging, product preservation, biotechnology and other industries, the quality of film blowing machine and blowing     Film technology determines the quality of film forming. So a good performance of the film blowing machine in the production of film process shows a good market adaptation     Ability to improve production efficiency while providing convenience for people to promote harmonious development of society.     Food packaging is the most widely used field of film, film blowing machine blown out of the high-grade film can be used as a commodity packaging publicity, improve commercial value. Today,     Film blowing machine development of high-end technology, film blowing can also be used as a number of applications such as food preservation technology, take the road of new film blowing machinery manufacturing. Blown film     Machine blown out of a special plastic wrap, the use of advanced technology, so that fruits and vegetables long - lasting.     The plastic wrap is made up of a nylon translucent film, which is nearly transparent and permeable, and is filled with a certain amount of sand syrup, gently wrap the surface of the article, this film must ensure environmental protection and harmless, at the same time has a strong water permeability, can absorb fruit and vegetable juice, to protect     Fresh purpose. This special material requires the LDPE Film Blowing Machine with high-end traction and wire drawing ability, to ensure the product film tough breathable.     A foreign company USES plastic film blowing mechanism to produce a new type of polyethylene film, this film is used in agricultural pesticide, not only can     They don't go bad, they don't get eroded by outside gases, and they're these amazing membranes that in addition to being able to store pesticides, they dissolve in water     And can draw patterns on the surface of the film. Blowing film driven by film blowing machine brings so much convenience to food processing and commodity packaging.     With the deepening of science and technology, the film blowing machine after continuous upgrading, will play a more role in promoting the plastic and packaging industry to the high-end Come in.     This article outlines the essential features and parts that comprise Pp High-Speed Film Blowing Machine. high-speed film blowing machine Pp as well as the operation that the equipment performs.     Are you interested in purchasing an equipment that will allow you the production of polyethylene film-like plastic? It can increase your company’s profitability and generate more money. If you are interested, purchase the top-quality film blowing machine.     Numerous companies are providing this kind model of equipment for their customers. Numerous business and private individuals in this business are purchasing this type of machine. Particularly within the United States, many are employing this equipment. Therefore, it is recommended to be aware of Pp High-Speed Film Blowing Machine. HP High-Speed Film Blowing machine.     What is the Machine?     This machine was specifically developed to produce PP that is Polypropylene film. The film is highly clear and high transparency. The film comes with a number of technological attributes. For instance, the machine is able to use ten sets of water rings. The water rings assist in the production for the films.     It also assists users to create various sizes of film products. Another aspect this machine performs involves manufacturing film production. To do this, a circular die shape is used to make the films. To make the film, the pressure of air is essential. The pressure of air is utilized to increase the thickness of the film.     ALSO READ  What Makes a Laptop Military Grade?     The Basic Nature of the Pp High-Speed Film Blowing Machine     The machine is made up of many components. It includes, for instance, the motor, screw barrel, inverter, tower, head and winder. For better efficiency in the working process it has frequencies control elements that can increase speeds of motors.     ALSO READ  Toys R US 2021 Black Friday Toys R Us 2021 Black Friday     The speed of the motors assists in controlling the machine’s speed and help to save energy. The alloy of chromium-aluminium-nitrogen is used to construct its barrel and screw.     What is it and how does it work?     There are a few steps of the machine’s work. The polymer is first dissolved in Pettet that is melted within the liquid that is viscous. The barrels and the screws work as an extruder in the High-Speed Pp Film Blowing Machine. The thick liquid permits the polymer to form shapes through dies or tubes.     Thirdly, the pipe has to be filled with air for safe rupture in a bubble by injecting by air. Fourthly the bubble is chilled by its cooling system. Fifthly, on its external surface the air ring can be utilized to help in the solidification of the material.     The frames are split in two by collapsing processes. Sixthly, following this procedure, the layers are formed into two-layered plastic films. Then , a circular roll is made to pack items. Seventhly, the procedure is in accordance with the specifications of machines’ models.     The Bubble Instabilities     When making films using the the the Pp high-speed Film Blowing Machine ,there is a possibility of bubble instability at the time of production. It is therefore necessary to be cleared to allow uninterrupted production. Since it causes the product to be in a variety of unstable and deforms in various ways, many different bubbles instability could arise, such as frozen line-height instability breath, bubble flutter draw resonance, tear of the bubble and helical instability. When it comes to time of production, it makes certain that the bubble’s instability doesn’t cause problems. So, it isn’t possible to cause the issues at the time of production.

Fecha de Publicación: 06-01-22

Valoraciones (0)