CULTURAL QA 07-2023-23 Q1 Why do aeroplanes use kerosene (parafin) as fuel?
KR Aviation fuels consist primarily of hydrocarbon compounds (paraffins, cycloparaffins or naphthene, aromatics, and olefins) and contain additives that are determined by the specific uses of the fuel. Paraffins and cycloparaffins are the major components. Generally, the octane number (ON) of gasoline is in the range of 70–97, whereas the octane number of kerosene is much lower at only 20–50. The question and the answer I misleading. Short flights' economical ranges do use 20-30 whereas long flights only use octane. Paraffin, kerosene etc are Hydrocarbon organic structures. In short kerosene is like diesel and octane is like petrol. Paraffin sold in medical shops is a waste product in the stages of refinements. Q2 Why do some metals corrode when exposed to air? KR In PUC we read, why even in school, that oxidation causes corrosion. All metals, with the exception of the precious metals, will oxidize when exposed to oxygen and an electrolyte (i.e. atmospheric moisture). It is a chemical reaction of the metal surface with the oxygen present in the air that causes some of the metal to corrode (or oxidize) and form the respective metal oxide on the surface. In some metals such as steel, the corrosion products formed are very visible and loose. Everyone has observed the red color of iron oxide (rust) seen on improperly protected steel products. The red rust formed is generally scaly and loose and easily falls away exposing more and more basis material to the environment. However, metals such as stainless steel (steel with added nickel and chromium) oxidize as well. The difference is that the nickel and chromium oxides formed are a more uniform and tenacious oxide layer that protects the underlying material by “sealing” the surface from further oxidation once formed. In addition to the surface oxidation that occurs on individual metals, any two dissimilar metals placed in contact with one another with an electrolyte (such as atmospheric moisture or water) will form a corrosion cell. This is the very basis of batteries used in everyday products. One of the two metals in contact will corrode in preference to the other and form that metal’s respective oxide. Which metal corrodes is based on what chemists call the electromotive series of metals. The selection of what plated layer to use is an important one since electroplating in its very essence is the process of placing two dissimilar metals in contact with one another. The plated layer (or layers) can either be an anodic coating (coating corrodes in preference to the substrate) or cathodic coating (substrate corrodes in preference to the plated layer). Whether a coating is an anodic or cathodic coating greatly impacts how the finishing system will perform once in service and there are advantages and disadvantages to each. Hence the answer is not to the point but reads as exception metals are subject to oxidation. Even if you store it in places, oxidation will occur. Q3 Have you ever gained respect for somebody instantly? KR With due respect to Ms Gurmeet, (as her friend she may regret but why all of us?) the Karma plays a vital part; the gold medallists are working as clerks and arrears subjects cleared are their bosses. Many scientists who are brighter than, lost in the running race inventions to juniors, who found it by fluke. Einstein rushed General theory and sealed further the processes; but only after 10 years explained the theory as special; even then the assembly of senior scientists having not known quantum mechanics accepted Einstein. Many names recommended for awards in chains did not get it. Among friends the feeling is Ok. Q4 Does Airtel still have a priority network for postpaid customers? KR Post paid are permanent customers and pay a lump sum every month, whether they use it fully or not and hence, so they get certain service priority. Pre-paid are travellers who get breakfast profits. I don’t know why question only about, particularly Airtel? Airtel service is poorer than BSNL. Q5 Why do airplanes prefer to fly over the ocean? KR Repetitive All the above QA are from the Quora website on 23 -07-2023. Quora answers need not be 100% correct answers. Compiled and posted by R. Gopala Krishnan, 79, on 23-07-2023. KR IRS 22 7 23 On Sat, 22 Jul 2023 at 18:35, gopala krishnan <[email protected]> wrote: > *CULTURAL QA 07-2023-23* > > > > Dear friends, > > As per the advice of a very senior member I will not be responding to > responses by Sri Rajaram and Sri APS Mani. Of course if they abuse I will > be writing back > > Gopalakrishnan 23-7-23 > > Q1 Why do aeroplanes use kerosene (parafin) as fuel? > > A1 Rebecca Williams, Experience in Aviation Jul 13 > > *Kerosene is a type of aviation fuel that is based on refined petroleum. > It is also known as jet fuel, aviation turbine fuel, or after*. There are > different grades of kerosene, such as Jet A, Jet A-1, Jet B, and JP-8, > which have slightly different specifications and properties. *They all > share some common characteristics that make them suitable for airplane > engines. Some of the advantages of kerosene are:* > > Kerosene has a high energy density, meaning that it contains a lot of > energy per unit of mass or volume. This allows airplanes to carry more fuel > and fly longer distances without refueling. Kerosene has an energy density > of about 43 MJ/kg or 34 MJ/L, compared to gasoline’s 46 MJ/kg or 32 MJ/L. > > Kerosene has a low freezing point, meaning that it remains liquid at very > low temperatures. This is important for airplanes that fly at high > altitudes, where the ambient temperature can drop below -50°C. Kerosene has > a freezing point of about -47°C, compared to gasoline’s -60°C. > > Kerosene has a high flash point, meaning that it requires a high > temperature to ignite. This makes it safer to transport and handle than > more flammable fuels, such as gasoline or diesel. Kerosene has a flash > point of about 38°C, compared to gasoline’s -43°C. > > Kerosene has a low viscosity, meaning that it flows easily and does not > clog up the engine’s fuel system. This is important for airplanes that have > complex and sensitive fuel pumps, injectors, and filters. Kerosene has a > viscosity of about 3 cSt at 20°C, compared to gasoline’s 0.5 cSt or > diesel’s 4 cSt. > > Kerosene is compatible with most airplane engines, whether they are piston > engines or turbine engines. Piston engines can run on kerosene with minor > modifications, such as higher compression ratios and fuel injection > systems. Turbine engines are designed to run on kerosene, as they use > high-pressure air and fuel to create thrust > > My note- paraffin oil is available in medical shops under prescription, > applied to bottom of the foot for pain under the foot. Prescribed by > Neuro doctors > > Q2 Why do some metals corrode when exposed to air? > > A2 Erika Fernandez,Bike Lover12h > > *Some metals corrode when exposed to air because they have a tendency to > lose electrons and form positive ions*. This tendency is called the > activity of the metal and it depends on the position of the metal in the > reactivity series. The reactivity series is a list of metals arranged in > order of their decreasing activity, from the most reactive to the least > reactive. The most reactive metals are at the top of the list and they can > easily lose electrons and form positive ions. The least reactive metals are > at the bottom of the list and they can resist losing electrons and forming > positive ions. > > When a metal is exposed to air, it can react with oxygen or water vapor > in the air to form metal oxides or hydroxides. *For example, iron reacts > with oxygen to form iron oxide, commonly known as rust.* This reaction is > accelerated by the presence of water or salt, which act as electrolytes and > allow the flow of electrons between different parts of the metal surface. > The iron atoms lose electrons and become iron ions, while the oxygen atoms > gain electrons and become oxide ions. The iron ions and oxide ions combine > to form iron oxide, which is a brown flaky material that does not protect > the metal from further corrosion. > > Some metals can also react with carbon dioxide or sulfur dioxide in the > air to form metal carbonates or sulfates. For example, *copper reacts > with carbon dioxide and water to form copper carbonate, which is a > greenish-blue substance that covers the surface of copper objects such as > statues or pipes. This reaction is slow and does not damage the metal > significantly.* > > Some metals do not corrode when exposed to air because they have a low > activity and can form a thin layer of metal oxide on their surface that > acts as a barrier and prevents further reaction with oxygen or water. For > example, *aluminum reacts with oxygen to form aluminum oxide, which is a > hard and transparent substance that adheres tightly to the metal surface. > This layer protects the aluminum from further corrosion and makes it > resistant to weathering.* > > Also few metals do not corrode when exposed to air at all because they > have a very low activity and do not react with oxygen or water under normal > conditions. For example, gold and platinum do not oxidize in air and remain > shiny and unaltered for a long time. > > My note-Informative answer told in simplest language > > Q3 Have you ever gained respect for somebody instantly? > > A3 Gurmeet Bishnoi, Lives in Berlin (2023–present)2y > > Do you know who is she -She is Dr. Raisa Ansari - She has PhD in physics > > *Raisa, a Master in Physics and PhD from Devi Ahalya Bai University of > Indore, received an offer to do research from Belgium*. But her research > head did not sign her recommendation letter. Her viva was not done until > two years after the thesis was submitted and then *she could get viva > after administrative intervention.* > > Raisa has done research from IISER (Indian Institute of Science Education > and Research), Kolkata on fellowship of CSIR (Council of Scientific and > Industrial Research). Due to a sign Raisa could not go to Belgium to > research. > > *Due to a sign and not any support, she is selling fruits. We all feel > sorry that such educated woman has to sell fruits but there is a fact that > she didn't give up.* > > She didn't compromise her honor. If her guide didn't sign her document, > still she started working by herself and earning for her. She is not > ashamed to do such work and I do feel proud for her honor. > > Q4 Does Airtel still have a priority network for postpaid > customers? > > A4 Gopala Krishnan, Former Asst General Manager, Retired at > Bharat Sanchar Nigam Limited (BSNL)Just now > > I am a post paid subscriber of Airtel. My bill comes under one family one > bill scheme now. Under this scheme all the existing connections become post > paid. > > Before I got my B S N L SIM In Chennai which was in high demand during > 2004 end, I had to purchase Airtel SIM. It was prepaid. At one time there > was a campaign to convert prepaid to post-paid. Paying a deposit I was > given ISD facility in prepaid which still continues. > > When there is a tower failure, automatically the customers are connected > to the nearest next tower. Depending on signal strength, you phone may/may > not function. > > No priority in any way for post paid customers in any manner in Chennai > > Q5 Why do airplanes prefer to fly over the ocean? > > A5 Mayfair Jets. Aviation Enthusiast May 15 > > *Have you ever wondered why your flight path curved over the ocean, even > though it seemed out of the way? It's all about efficiency and safety, > friends! Let's dive into this fascinating aspect of air travel.* > > *Aircraft often follow what's known as the "Great Circle" route. This > might look curved on a flat map, but it's actually the shortest distance > between two points on a globe*. When you're traveling thousands of miles, > following a Great Circle route saves time and fuel, even if it seems to > curve oddly over the ocean. > > Over the ocean, air tends to be less turbulent compared to over land, > thanks to the uniform temperature of the sea surface. > > This means less bouncing around for you and your in-flight drink! So, the > next time you're on a plane, *look out of the window and appreciate the > ocean beneath - it's not just a pretty view, it's part of smart and > efficient aviation.* > > *All the above QA are from Quora website on 23 -07-2023.* > > *Quora answers need not be 100% correct answers.* > > *Compiled and posted by R. Gopala Krishnan, 79, on 23-07-2023.* > > > > -- 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/CAL5XZoorh3ZH09K56zu5NBnwWeL2EJ7eC7WghfD3M25SQYAE7w%40mail.gmail.com.
