Pranam 1Conductivity superiority is based upon, not on the metal but on a particular property, omitted here, to be mentioned; MALLEABILITY. Every element in our universe is defined by its atoms. These determine every one of its characteristics, including its shape, colour, conductivity, melting point, strength, and malleability.Metals are one of the most malleable materials in the universe. But why are metals malleable, exactly? What is it about their atomic structure that makes them so easy to manipulate? The answer is in their electrons—those little electronically-charged particles that whizz around their atom. Many metals have an atomic structure with shared valence electrons, which are electrons that sit around the outer shell of an atom, and can easily form chemical bonds. When a metal has these kinds of electrons—for example iron, aluminium, and copper—they’re highly malleable when heated, because the atoms are able to easily slide over each other2, allowing us to hammer them into useful shapes. 2 Malleability and ductility are two similar properties that are often confused. In metallurgy, a malleable material is one that can be easily formed by hammering, rolling, or pressing it. The material is considered malleable because it can be manipulated under *compressive* stress. By contrast, ductility is the ability of a material to be manipulated under *tensile* stress, which is how easily it can be stretched. A material that can be easily stretched into a wire is considered ductile. 3 Ductility: It is the property of a metal that can be drawn into wire. Ductility and temperature are inversely proportional. The ductility of the metals decreases as the temperature increases because metals become weak at high temperature. Malleability: The ability of metal <https://byjus.com/chemistry/metal/> that can be beaten into thin sheets is called malleability. Malleability and temperature are directly proportional. Malleability increases with an increase in temperature. Most malleable and ductile metals; Gold and silver are the most malleable and ductile metals.
- An ounce of gold has the capacity to be drawn into a wire more than 40 miles long. Gold and silver, when present in their pure states, are too soft for making objects that will last for long. - The fineness and purity of gold is measured in karat and that of silver is measured in percentage. 4 *Michael Dickey: * Sure, I'd be happy to. My name is Michael Dickey and I'm a Professor of Chemical and Biomolecular Engineering at NC State University in Raleigh, North Carolina and although my training is in polymeric materials and nanofabrication my group has been studying liquid metals for about a decade now. These materials are interesting because they are both liquids and metals. Most people think of mercury when they hear the term liquid metal, which is a bit unfortunate because mercury is known to be toxic. Instead, our group and others have been studying liquid metal alloys of gallium, which are considered to have low toxicity relative to mercury. Importantly these metals form surface oxides that act like a thin shell and this oxide shell allows the metal to be patterned and manipulated into shapes that would not be possible with conventional liquids like water. We have been studying these materials and taking advantage of their properties to make soft and stretchable electronics in our group. *Stewart Bland: * So in your recent study published in Extreme Mechanics Letters you reported on a new method to create flexible wires using polymers surrounded by liquid metal. Before we get into the technical details of how, can you tell us about the need for flexible electronics? *Michael Dickey:* I'd be happy to. There is a lot of interest right now in making electronics that are flexible and in some extreme cases, stretchable or even soft. There are at least two reasons I can think of for this interest. The first is just simply to give electronics greater functionality. A simple example of that would be a phone that could be folded for example. The second is to put electronics in places where it is currently difficult. An example of that might be some electronics on or inside the body, maybe within or on clothing or in other things that we come across in our daily lives. If you sort of take a step back and think about it, our bodies and many of the things that we interact with in our daily lives are soft and deformable and, in contrast to that, most electronics are made from rigid materials. Ultimately there is a mechanical mismatch between the electronics that we have and our bodies and the things that we experience day to day. So, our group and a number of other groups around the world have been looking at ways to make electronics with interesting mechanical properties and we've tossed around a couple of words here - flexible, stretchable, and also soft, and if you think about flexible, it's possible to make electronics flexible by simply making the components thin and there are plenty of examples of this in our day to day lives. For example, aluminium foil is flexible because it is thin even though bulk aluminium is a very rigid material. In fact, you can make bicycle frames out of aluminium. We've been really trying to go a step beyond flexible electronics to try to make conductors that are stretchable and also soft. 5 *Stewart Bland: * So you used a liquid metal core surrounded by a polymer and that's a liquid metal at room temperature. Can you tell us a bit more about these exotic metals? *Michael Dickey: * We're studying alloys of gallium. Gallium is directly below aluminium on the Periodic Table, which is another way to say that they are related and have similar properties but there is one major difference. That is that gallium has a melting point of approximately 30 degrees Celsius, which means that if you were to hold it in your hand your body is sufficiently warm to melt the metal and turn it into a liquid. In our case, we ensure that it stays as a liquid at room temperature by adding other metals to it. In this case we add indium and adding those things together lowers the melting point below room temperature to ensure that it stays liquid throughout our experiments and our application. Liquid metals, as you may know, have very large surface tension and that causes them to want to beat-up to minimise their surface energy. If you've ever had the misfortune of breaking a mercury thermometer, you'll know that the mercury will beat-up into the shape of a sphere due to its large surface tension. So, this is really a problem if you want to pattern a liquid metal into a useful shape such as a wire, for example. There are other examples of this beyond mercury. Even water has a pretty large surface tension so if you were to turn on your faucet, you would see that a cylinder of water comes out of the faucet but it eventually breaks up into droplets due to surface tension. So, if you want to make a wire or something like that, that is stable, that's a challenge with liquid. Fortunately, gallium has a property that allows it to be patterned into stable shapes and that is that gallium reacts rapidly with air to form a thin oxide skin on its surface. The skin is only a few nanometres thick so it is quite thin, but it allows the metal to be moulded and manipulated into stable shapes that are none-spherical such as wires and, not quite a perfect analogy, but I like to say that the oxide skin is similar to how a water bed contains mostly water but yet it is held into the shape of a bed by a thin plastic bag that surrounds its surface and so this is sort of similar, but on a much smaller length scale. *Stewart Bland: * So, how do you go about creating these wires? *Michael Dickey: * Simply stated, we just place a droplet of liquid metal on a piece of putty and stretch it. This process is very much like stretching a piece of bubble gum and in our case, because the liquid is a metal, it stretches along with the putty. So, you stretch the putty, you also stretch the metal and the two things move simultaneously. When you do the stretching, the oxide skin breaks and reforms as you elongate it and again, to reiterate, without the skin the metal would just beat-up into a sphere or drop but with it the metal can form stable wire shapes. This whole process was inspired by the processes that are used to make fibre optic cables. In that process, a cylinder of glass is heated and simultaneously pulled into the shape of a fibre. In our case, we did not need to heat the materials because they were already soft at room temperature. The whole process is literally then at room temperature by hand. The resulting wires that we form consist of liquid metal encapsulated in polymer and in our work we explored several different putty-like materials including those that could be cross-linked after stretching to lock the structures into place. In other words, once you stretched it, you don't want it to be a putty anymore. You want it to have found desired mechanical properties. Depending on the chemistries we employed, the wires could either be stiff or they could be elastic or rubber-like. We also showed it was possible to stretch the wires into a variety of shapes so they don't have to just simply be a straight line. It could be something you stretch out into the shape of a plus or a star or some other shape. We also showed that you can control the diameter of the wires based on how far you stretch them. I think the smallest we got was about 10 microns diameter, which is about an order of magnitude smaller than the diameter of a human hair. So, the wires could be large but they could also be very small at the extreme. *Stewart Bland: * So what kind of applications could these wires be suited to and are there any specific pros and cons? *Michael Dickey*: This approach allows for wires to be formed on demand, which might be useful for repairs or for the military, for example to create antennas in the field of operation. The materials can be stored in a compact shape. They can be held in your pocket or in a bag and then be elongated into whatever shape is needed on demand. Now one of the limitations here or a drawback is that liquid metals are more expensive than typical wire materials like copper. Personally, I don't envision this concept to replace existing wires and it really only makes sense to use this approach if the added features justify the added cost. *Stewart Bland: * So what's next for this project? *Michael Dickey:* The wires that we formed were all done by hand, which limited the length of the resulting wires and also limited the reproducibility. Ideally, it would be preferable to also use machinery to do the elongation and that is something we are currently looking at. One of the important things that I would like to point out is that this work was all done by really excellent graduate students and also in collaboration with some of my colleagues in my department and I'm really thankful for all their efforts. *Stewart Bland: * Fantastic. Well, to finish then, I'd like to ask, as always, in your opinion what are the hot topics in materials science right now? *Michael Dickey:* Well, I'm going to show off some that I'm a little bit partial here because it’s an area that I'm personally interested in but I am partial to soft materials and I think there is genuinely a lot of interest in this topic right now for a number of reasons. Where I live in the research triangle in North Carolina there is a lot of interest at the universities that are in this region. I'll just give you an example. In our group, we are interested in soft conductors and actuators including the liquid metal we just talked about. The human body provides once source of inspiration for this work since the body has, for example, nerve networks, memory sensors and many other complex mechanisms that are built entirely from soft materials and there really are very few man-made analogues that can mimic what our body can do using soft materials yet it would be interesting to make systems like these to create new devices that have the functionality that we find in the body built entirely from synthetic materials and to make interesting devices. 6 Mercury Wire offers a variety of shielding options using metal, tapes, and fiber shields to accommodate a vast range of application requirements. The process of shielding a cable may involve the application of a series of strands of copper or other metal such as aluminum or steel around one or more insulated conductors. When metal is used, shielding a cable is typically accomplished by wrapping several strands of metal around conductors in a braid-like pattern. For this reason, braiding is often used synonymously when referring to the shielding process. Shielding may also be accomplished through a non-braided spiral winding of copper tape or another layer of conducting polymer. In most cases, a final jacket is applied to a shielded cable to protect all inner components from environmental factors. In practice, a shield may be applied to a cable for a variety of reasons including, but not limited to the following: • Reduce electrical noise that may affect signals traveling through the cable • Minimize electromagnetic radiation that may interfere with adjacent devices and equipment • Protect cable insulation, people and equipment from exposure to high-voltage power • Minimize electromagnetic interference from other electrical sources 7 Mercury is the only elemental metal that is liquid at room temperature. (Cesium <https://www.britannica.com/science/cesium> melts at about 28.5 °C [83 °F], gallium <https://www.britannica.com/science/gallium> at about 30 °C [86 °F], and rubidium <https://www.britannica.com/science/rubidium> at about 39 °C [102 °F].) Mercury is silvery white, slowly tarnishes in moist air, and freezes into a soft solid like tin <https://www.britannica.com/science/tin> or lead <https://www.britannica.com/science/lead-chemical-element> at −38.83 °C (−37.89 °F). It boils at 356.62 °C (673.91 °F).{ Hence it is classified as Metal}. . This red or yellow crystalline solid <https://www.britannica.com/science/crystal> is also used as an electrode <https://www.britannica.com/science/electrode> (mixed with graphite) in zinc-mercuric oxide electric cells and in mercury batteries. Mercury(II) sulfide, HgS, is a black or red crystalline solid used chiefly as a pigment in paints, rubber, and plastics. Hence mere application of 5 Ws lands one into quixotic trouble which quora readers often do. Theory is deeper than the mind can think of. Thank you KR IRS 16522 On Mon, 16 May 2022 at 03:30, 'gopala krishnan' via iyer123 < [email protected]> wrote: > *CULTURAL QA 05-2022-16* > > *BEING A COMPILATION THERE MAY BE ERRORS* > > Q1 Why does copper wire conduct more than gold wire? > > A1 Gopala Krishnan , former Assistant General Manager 1996-2004 > at Department of Telecom (1966-2004)Answered just now > > The conductivity of gold is only 70% of copper. It is a material quality. But > gold is not corrosive. Hence for relay contacts gold is used. Scrap > merchants purchase old relays for very high price on account of it. > > Q2 Does having a large amount of ear wax within the ear worsen > other existing hearing problems like tinnitus? Why or why not? > > A2 Ken Saladin Textbook author and professor emeritus16h > > *Tinnitus is a symptom of an underlying disorder of the cochlea*, > cochlear (auditory) nerve, or auditory processing areas of the brain, or of > the blood vessels that supply these structures in the hearing system. *Since > earwax is limited to the outer ear, I find it difficult to see how it could > cause tinnitus*. However, the U.S. National Institute on Deafness and > Other Communication Disorders says “*Something as simple as a piece of > earwax blocking the ear canal can cause tinnitus.*”[1] The mechanistic > connection eludes not just my knowledge but even my imagination. > > Other causes of tinnitus listed by the same source are: Noise-induced > hearing loss, Ear and sinus infections, Diseases of the heart or > blood vessels, Ménière’s disease, Brain tumours, Hormonal changes > in women and Thyroid abnormalities > > Q3 Were you shocked when you realized you’re now 65 years old? > > A3 Prasanna Bhalerao M. Sc. in Electronics & Physics, Fergusson > College, Pune21h > > *I am not 65 yet.* I am 59 right now. I retired last year. Very soon I > will be 65. It has not shocked me. I look upon my life with some > satisfaction and some regret. I didn't have it easy for most of my younger > days. But as I approach the older years, I am satisfied. It is not like a > movie (13 going on 30, Big) that I woke up and suddenly found myself much > old. So there is nothing suprising here.Every evening I go for a walk > between 7 and 8 pm and make it a point to visit the local Hanuman temple. I > thank him and Lord Ram for my life and what I have today. I tell Him that I > am satisfied and want nothing for myself receipt good health. I pray that > my son sees the same happy path. Without fail I also pray that there are > many devotees in this world who suffer or are suffering for maybe sins of > previous life and I request Him to uplift them. (Really and sincerely > honest). That is also the reason I started writing on Quora on finance — to > help people. > > While it doesn't shock me, it is sometimes amusing to see young friends, > some who are my son's age. > > *My note- Either at 65 or 75, when one feels that he has physical > difficulties in sitting in floor and getting* up, difficulty for more > walking, not able to exert physically, feels more tired, one feels he is > old is my view. > > Q4 I booked a ticket on IRCTC using PhonePe. PhonePe says > transaction is successful, but the ticket appeared nowhere on the IRCTC > website, booking history or failed transactions. What should I do? Will I > get a refund or will I get my ticket? > > A4 Jakir Ansari Toll-free Servic=839-1091-797=customer Care > Number at Plot No.98/09, 100 Feet Road, Mehrauli Ghitorni, New Delhi > (1995–present) May 9 > > You booked a ticket on IRCTC using PhonePe. PhonePe says transaction is > successful, but the ticket did not appear anywhere on the IRCTC website. > > In this case, you will get the refund back to your respective bank account > within 3-4 working days. No need to worry for your refund. > > Q5 When I plug my laptop and phone to charge, and touch bare > metal sides of both devices, I get electrocuted, and multimeter shows 220V > AC between these surfaces. Why is this happening, considering that one > charges at 20V and another on 5V? > > A5 Loring Chien electrical engineer and audiophile for 45 years > May 9 > > *First, you got shocked, not electrocuted*. If you got electrocuted, you > would be dead… Electrocution is killed by shock. *You had a non fatal > shock*. > > There is some failed isolation insulation between the inputs and outputs > of the chargers that makes the cases live. > > *Be careful! Maybe you need two new chargers. when unplugged, there should > be no continuity* between either of the AC prongs and the two conductors > of the power cord of the laptop or the phone (although you usually can’t > easily get to the phone connector you can check the case (while plugged to > the charger but the charger not plugged in) and either of the two prongs. > Same with the case of the computer > > Q6 What is a better insulator, cotton or plastic? > > A6 Gopala Krishnan, former Assistant General Manager 1996-2004 > at Department of Telecom (1966-2004)Answered just now > > *Better insulator is cotton*. We can see cotton braiding over rubber/pvc > insulated plugging in wires of electric irons. But cotton is subjected > to wear and tear. Hence thick PVC is used over most conductors now. At one > time it was rubber insulation. > > *One defect with cotton is when it becomes wet, it becomes a conductor.* > In telecom department *at one time* telecom staff used to put through > broken wires using *wet cotton turban* if conductor bit was not available > to restore communication. Lengthy cotton turbans were given to field staff > at one time. > > Q7 Karnataka has South Western Railway zone, AP and Telangana > has South Central Railway zone, don't you feel Kerala also needs a separate > railway zone instead of being under Southern Railways headquartered at > Chennai? > > A7 Aravind Varier Teacher (2011–present)Apr 21 > > I DO NOT find any merit in Kerala having a separate railway zone due to > the following reasons. > > 1) Kerala Government have ZERO influence in taking decisions even when > Kerala gets a separate railway zone. It is the ministry of railways that > takes the final decision. > > 2) Presently, Member of Parliament from Kerala plead in front of the Union > Government for improving the railway network in the state and this is NOT > going to change even when a separate railway zone is allotted to the state. > > I would like to have a permanent solution to the problems faced by Kerala > instead of wasting time in asking for a separate railway zone for Kerala. > > *I recommend the Kerala State Government to move a resolution in the > Assembly demanding that Kerala should receive **₹** 75 in return for > every **₹** 100 that it gives to the Union Government. [1]* > > Presently, Kerala gets less than ₹ 50 for every ₹ 100 that it gives to > the Union Government. > > If Kerala starts receiving ₹ 75 for every ₹ 100 that it gives to the > Union Government, then Kerala Government can build a High speed Railway > Network travelling at a speed of 300 Kmph from Kasaragod to > Thriuvananthapuram within a decade using its own money instead of taking > huge loans from International Institutions at high interest rates. > > Once a high speed railway network is built from Kasaragod to > Thiruvananthapuram, Kerala Government can easily encourage people to travel > in the high speed Railway Network instead of the trains operated by the > ministry of railways. > > My Advice > > Malayalis should build a High Speed railway network in Kerala by demanding > their rightful money which is taken away by the Union Government for > spending it in some other states. > > *My note- A separate railway zone get more powers for railway works in the > area. It is beneficial only.* > > Q8 What happens if you drink more milk daily, any limit or side > effects? > > A8 Lucia Garcia Worked at Hospitals Wed > > Milk is highly nutritious and an important part of our balanced diet. > > There are many benefits of drinking milk, which can supplement various > nutrients necessary for the body, such as protein, fat, minerals, vitamins, > etc., to stimulate bone growth and maintain bone density. > > *Although the U.S. National Dietary Guidelines recommend that adults drink > 3 cups or 732 mL/d of milk per day, many experts believe that Drinking 1 to > 2 Cups of Milk Per Day is Sufficient.* > > Milk contains large amounts of D-galactose, which is a physiological > nutrient that can be converted into glucose in normal body metabolism. > > *However, excess D-galactose can induce systemic oxidative stress, which > can lead to chronic inflammation and many chronic diseases.* > > Starting in 1987, Swedish experts spent 32 years studying 61,433 women and > 45,339 men of different ages. > > The findings, published in the UK's top medical journal BMJ, found "a > significantly positive association between milk consumption and > osteoporosis, fractures and mortality." > > *Researchers believe that drinking large amounts of milk increases the > risk of osteoporosis, fractures and death, and the culprit is D-galactose.* > > Q9 Is a blood sugar level of 225 harmful? > > A9 JenM's Diabetes & Blood sugar Corner Answered byJen M May 10 > > *There is no definitive answer to whether a blood sugar level of 225 is > harmful or not, as this will vary from person to person*. *In general, > however, a blood sugar level that is too high can be dangerous for people > with diabetes, as it can lead to serious health complications such as heart > disease, stroke, and kidney failure*. If you are concerned that your > blood sugar level may be too high, it is important to speak with your > doctor about ways to lower it. > > *An unbalanced blood-sugar can impact adversely! Check out this formula > that supports healthy blood* sugar (glucose) levels which helps balance > your blood sugar, restful sleep & hunger cravings. > > My note- If one who take insulin before food fail to take insulin *at > one time before food*, effect of high glucose remains for three days. > > Q10 If I travel in 3AC with general ticket what fine should I pay? > > A10 Ramesh S BA degree in Economics from Maharaj's College, > University of Mysore. (Graduated 1982)Fri > > *It depends on train position, if coach is full you may have to pay > penalty upto the point of checking* and onwards charges as per available > accommodation or you may be detained. Since accommodation not available. It > including minimum penalty as applicable in particular case. > > *If any vacancy is available up to that destination of ticket, then they > have to pay only difference of fare.* > > Q11 Why do Dutch houses have sinks in bedrooms? > > A11 Brian Scott Gould Lived in The Netherlands Apr 24 > > *It is something old fashioned you will only find in houses built in the > first half of the 20th century or before.* > > When I first moved to the Netherlands, it was something I found very > strange. It was like *“You can wash here because we would rather not have > you in our bathroom”.* > > The reality is quite different. Bathrooms and showers are something > relatively new. In the 1920s and before, ordinary people didn't have one. > In days of old, people had a basin and a pitcher of water on a nightstand. > As we modernized, this was replaced with running water and a drain. Warm > water was the next improvement. *To provide someone with a private place > to wash was quite a luxury. It was the pinnacle of privacy.* > > So what about the bathroom you might ask? *You didn't have one. If you > lived in the city, you went to a bathhouse. Every neighbourhood had one.* > > * My wife tells me how their normal routine in the 1960s was to walk with > her brothers and sisters to the local bathhouse twice a week. If you lived > in* the countryside then the choice was a sponge bath or breaking out the > big galvanized tub and washing in that. If you didn't feel like visiting a > bathhouse or thought it was too far then this was an alternative for the > city dweller as well. > > *A side note about bathing:* > > One interesting in-between solution that was seen in dwellings built in > the 1950s was called the lavet. > > It was a compact mini tub. You could use it as a footbath, sit bath, wash > the kids in it and with a special attachment you could use it as a washing > machine. *The downside was it that remained small and required careful > washing as water could potentially splash out onto the floor*. Also, it > was quite a climb to get in and out of. The possibility of twisted/broken > limbs and bashed noggins seems fairly probable. In the course of my career > as a plumber, I have torn out dozens of these contraptions. > > *All the above QA are from Quora website on 15-05- 2022. * > > *Quora answers need not be 100% correct answers .* > > *Compiled **and posted by R. Gopala krishnan on 16-05-2022* > > > > -- > You received this message because you are subscribed to the Google Groups > "iyer123" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/iyer123/1535321520.2633660.1652652039005%40mail.yahoo.com > <https://groups.google.com/d/msgid/iyer123/1535321520.2633660.1652652039005%40mail.yahoo.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Thatha_Patty" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/thatha_patty/CAL5XZooZQSf%2BRR%2BKNinXODuVWsycq%2BpGekURpUVkwVF%3DFMy_Ug%40mail.gmail.com.
