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+--- موضوع: What is Additive Manufacturing (AM)? (/Thread-What-is-Additive-Manufacturing-AM)
What is Additive Manufacturing (AM)? - kl669ww - ۱۴۰۰/۱۰/۲۹ ۰۸:۱۹ صبح
A technical committee under ASTM international finally defined these processes appropriately as Additive Manufacturing (AM), as the technology builds 3D parts by adding material, as compared to subtractive manufacturing.According to ISO/ASTM 52900-2015, دیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
manufacturing is commonly given to the technologies that use successive layers of material to create a three-dimensional object. By using various techniques the printer builds the 3D geometry by constructing a thin 2D plane layer by layer.There are seven main categories of AM technologies viz Vat photopolymerisation, Material Extrusion, Material Jetting, Binder Jetting, Powder bed fusion, Direct energy deposition and Sheet lamination.Additive manufacturing technology typesMany companies have invented and introduced new techniques and Because the technology is fairly new, the companies who develop and introduce different techniques come up with their own marketing terms for the process, even though the core technique might be the same.As per ISO/ASTM standards AM can be divided into the following seven process categories or types according to the techniques used to create those layers. Though companies who have developed some of the AM technologies have their own names.Vat Photo PolymerizationIn this process, a liquid photopolymer is selectively cured by light-activated polymerization to create a 3D part. It is based on the curing and hardening of photopolymers on exposure to ultraviolet radiation. The main types of this technology are Stereolithography (SLA), Digital Light Processing (DLP) and Continuous Digital Light Processing. Only Plastic can be printed using these technologies.Binder jetting processAs the name implies this technique selectively deposits the bonding agent a binding liquid to join the powder material together to form a 3D part. This process is different to any other AM technology as it does not employ heat during the process like others to fuse the material.Directed energy depositionDirect energy deposition uses focused thermal energy such as a laser, electron beam, or plasma arc to fuse materials by melting as they are being deposited. Types include LENS, EBAM.Benefits of cosmeticsWhile some people believe that دیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
and personal care products are a recent invention, discoveries of their use and widespread benefits go back thousands of years. Today, Europe’s 500 million consumers use them to protect their health, enhance wellbeing and boost their self-esteem.Functional benefits[size=medium]
Cosmetics contribute to wellbeing and healthy lifestyles. Our hands carry pathogens from contaminated sources; so simple tasks such as washing hands with soap can help prevent serious illness. Indeed, multiple studies have shown that the leading causes of child mortality in developing countries, diarrhoea and respiratory infections, can be prevented by hand washing with soap. The use of toothpaste, particularly when containing fluoride, reduces the prevalence of dental caries. Toothpaste reduces plaque and tartar, which can lead to tooth damage and gum disease. Beyond health, there are economic advantages to dental care: there is strong evidence that the benefits of preventing tooth decay far exceed the costs of treatment. Indeed, if we assume that, without toothpaste, total expenditure on oral health would be 5% higher, the total benefits of using toothpaste (in terms of avoided costs) would be approximately �26.5 billion by 2020.
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Exposure to ultraviolet radiation is the only established exogenous causal factor for melanoma, a type of skin cancer that can spread to other organs of the body. Consistent and optimal use of sunscreen may prevent the incidence of melanoma. A study carried out between 1992 and 2006 and reported in ‘Reduced melanoma after regular sunscreen use: randomised trial follow up’ in the Journal of Clinical Oncology (2011) examined the cancer rates of two groups of adults aged between 25 and 75 years old. One used sunscreen daily and the other did so at their discretional frequency. It was found that invasive melanoma was reduced by 75% for approximately 15 years after trial cessation in the group that applied sunscreen daily.
Emotional benefits[size=medium]
Beyond physical health, cosmetics can help to improve our mood, enhance our appearance and boost our self-esteem. They can also help to exhibit personal style and, as such, are an important means of social expression. In a study by FEBEA, over 60% of respondents claimed that cosmetics have a positive impact on well-being, image, self-confidence and mood, with a large proportion (+40%) also identifying benefits in terms of social life, love life, family life, professional life and health.
A study published by IKW, the German Cosmetic, Toiletry, Perfumery and Detergent Association, assessing the self-perception of adolescents and young adults, found that 73% believe body and beauty care is very important in their lives. Moreover, 85% feel safer when they use cosmetics products, and 63% feel more attractive when they do so.
Synthetic Chemical
[size=medium]دیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
s are usually applied as additives in everyday products, which can help to improve the flexibility and versatility of these materials. For instance, plasticizers and flame retardants are commonly used in plastic products and electronic دیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
respectively. However, many of the chemicals used in these products will inevitably enter the environment. Some synthetic chemicals can exhibit environmental persistence and possess characteristics of bioaccumulation, which can induce acute or chronic toxicity for organisms and further influence both ecological and human health. Therefore, despite the fact that the chemicals in these products play an important role for promoting the development of human society, the risks they pose to the environmental health of our planet must not be neglected.Biopeptide Basics[size=medium]Proteins and peptides alike are made of strings of proteinogenic, or standard, amino acids-22 organic chemical building blocks found in the human body. Depending whom you ask, a protein-to gain its moniker-must have more than 20, 40, or 50 amino acids; an average protein in the human body, though, is much larger than this, with somewhere around 500 amino acids. A دیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
is any string of at least two amino acids that has fewer than this designated cut-off-a few dozen building blocks rather than a few hundred.
The differences between proteins and peptides, while they are rooted in size, do not end with how large or small they are. Because peptides are so short, they generally do not fold into complex structures like larger proteins; instead of forming helices, sheets, large complexes, and globules, peptides remain a loose, two-dimensional string inside cells. And because of both their small size and lack of organized structure, peptides tend to be able to sneak through spaces where larger proteins can't fit-they can penetrate the walls of the intestines, human skin, and in some cases even the membranes surrounding cells. For drug makers or food engineers, this is one of the most appealing qualities of biopeptides; they can quickly get to the bloodstream to go where they are needed. In addition, short peptides can be simpler and cheaper to produce compared to complicated, larger proteins.
To make proteins, machinery inside a cell's nucleus first transcribes a strand of DNA (deoxyribonucleic acid) into a corresponding strand of messenger RNA (ribonucleic acid; mRNA). Next, in association with ribosomes outside of the nucleus, each triplet of m RNA, or codon, is translated into an amino acid that makes up a growing protein. Finally, the protein might be processed by the cell through the addition of chemical entities on the string of amino acids or the removal of sections of the strand.
When it comes to peptides, a few are produced through this classical protein-making pathway. But the vast majority come from elsewhere: the food we eat. When you drink a glass of milk or chow down a burger, your digestive system is faced with thousands of proteins from the food. In the process of digestion, many of these proteins are broken down into smaller, manageable chunks: peptides. Some of these have no immediate function-they will go on to be further processed so the body can later use their building blocks. But others are bioactive peptides; bioactive in the sense that they can cause a change to a cell's functioning. It is these that have caught researchers' attention.What Are Consumables?[size=medium]دیدن لینک ها برای شما امکان پذیر نیست. لطفا ثبت نام کنید یا وارد حساب خود شوید تا بتوانید لینک ها را ببینید.
s are goods used by individuals and businesses that must be replaced regularly because they wear out or are used up. They can also be defined as the components of an end product that is used up or permanently altered in the process of manufacturing such as semiconductor wafers and basic chemicals.[size=medium]Stocks of companies that make consumables are considered safe harbors for equity investors when the economy shows signs of weakness. The reasoning is simple in that people always need to purchase groceries, clothes, and gas no matter what the state of the broad economy.[size=medium]
[size=medium]Many of the items measured in the basket of goods used to calculate the consumer price index (CPI) are consumables. Inflation in these items is closely watched because it can lower the discretionary income people have to spend on items such as cars, vacations, and entertainment.[size=medium]
[size=medium]Since staple goods are consumed at all times, they are considered non-cyclical, while more discretionary products are cyclical and can vary in demand with the economy.[size=medium][size=medium]Consumables Examples[size=medium]While certain consumables like food, gasoline, clothing, and personal hygiene products are ubiquitous, the world of consumables also has some interesting niche areas and sectors. Here are just a small set of examples.