CULTURAL QA 05-2023-28 BY Mr G AND EDITED BY KR IRS 28523 Q1 Why do airliners have to fly at 250 knots when they are below 10000 feet?
G My note- Telecom department was having a training centre at Meenambakkam, somewhat close to airport. While attending/ taking class, due to heavy noise from aircrafts, it was customary to keep silence than teaching. Now the BSNL is conducting much training for those requiring employment in all fields, not only for BSNL. KR: Being enthusiast had copied from material dot and dash without understanding the theme. And the above note has no relevance to the subject at all. 5 lines are waste fillers. Now, *What Do You Think? *Does the 250-knot speed restriction below 10,000 feet make sense? Do you think it should be increased or decreased, and under what circumstances? The replies from the pilots who are operating day in and day out:” 1 *Nico Wissink *It used to be that the "heavy" call sign would enable you to clean up at speeds above 250, below 10.000. The 747 I fly might need 280 at heavy weights. ORD and LAX require you to stay at 250 until they tell you otherwise, and the speed margin to the bottom gets very narrow the higher you go, with flaps at 5 or 1. As for levelling at 10.000 on the way down, yes, I have seen the plane do that, but it also can reduce to 700fpm at 12000 ft and hit 250 (it tries for 240) at 10.000. Pilots that use Flight Level change occasionally forget the speed reduction, and level at 10.000. At ORD they want you to go 300 kts at 11000, after a previous 250 kt restriction. Then clear you to 7000 few seconds later, at what point do you want me to go 250 again? It takes fuel to accelerate, now, 2 minutes later I need to waste all that energy again? Then Tower cries if I need 185 on final and they want me below 170. Maybe ask first? (fuel wasted literally) .2 *Ed Jones *250 KIAS seems ok given the flap speed restrictions on faster aircraft. Most commercial aircraft can operate between 180 and 250 without adding flaps. and be safe. Often rule changes occur after several events that draw attention to a problem. The TWA, Beechcraft and UAL events were not the sole reasons for the rule change. 3 *John Frank* <https://www.facebook.com/people/John-Frank/100054199173724/> The author is incorrect. The UAL/TWA December, 1960 mid-air resulted in a speed limit of 250 KIAS within 30 miles of the destination airport. More than 30 miles from destination, go barber pole at 6,000 feet, msl, if you wanted to. In April, 1967, a TWA DC-9-10 was doing just that (barber pole at 8,000) when he rammed into a Beechcraft. That April, 1967 accident resulted in 250 below 10,000 everywhere in domestic U.S. airspace. Q2 Exactly what do we need to filter out of our tap water? Certainly not everything in tap water is harmful, is it? G The ugly actual truth is that you don’t actually need to filter anything out of most tap water! (KR Is that universal statement or USA statement? It appears to be a Detroit USA standard not applicable to India or Africa) G My note- While I had training as phone inspector (1965’s) we were told only tap water is used for preparing batteries, but in India we use distilled water as tap water is not pure in India. Water was so pure in London at that time. During my student days in Kerala (till 1964’s) we used water from wells for drinking. It was filtered only during rainy seasons. Basic water filtering was only known using charcoal saw dust and sand and was available in major offices. KR The *history of water filters* can be traced to the earliest civilisations with written records. Water filters have been used throughout history to improve the safety and aesthetics of water intended to be used for drinking or bathing. In modern times, they are also widely used in industry and commerce. The history of water filtration is closely linked with the broader history of improvements in public health. Ancient Sanskrit and Egyptian writings document practices that were followed to keep water pure for drinking. The *Sushruta 2000 BCE Samhita <https://en.wikipedia.org/wiki/Sushruta_Samhita>* specified various methods, including: boiling and heating under the sun <https://en.wikipedia.org/wiki/Sun>. The text also recommends filtering water through sand and coarse gravel. Images in Egyptian tombs, dating from the 15th to 13th century BCE depict the use of various water treatment devices. By the early 1900s, water treatment experimentation had turned from the prevention of waterborne diseases to the creation of softer, less-mineralized water. Water softeners, which use sodium ions to replace water-hardening minerals in water, were first introduced into the water treatment market in 1903. Ion exchange is a reversible interchange of one kind of ion present in an insoluble solid with another of like charge present in a solution surrounding the solid with the reaction being used especially for softening or making water demineralised, the purification of chemicals and separation of substance since 1900AD and in 1960s we had a system and not saralikkal treatment as shown in “my note by G”. <https://en.wikipedia.org/wiki/Ion_exchange> Q3 What fruits are good for diabetics? KR repeated again G End note: My job is to give you good advice, but you must consult a doctor before taking my advice. KR Advice must be given only appropriately and not as , “small lettered caution below in any advertisements”. Q4 Does powder or liquid laundry detergent work better? KR repeated again Q5 How is electricity obtained in trains? KR Repeated again under another banner a few months back. Compiled and posted by R. Gopala krishnan, former ITS, on 27-05-2023 KR IRS 27523 On Sat, 27 May 2023 at 07:13, '[email protected]' via iyer123 < [email protected]> wrote: > *CULTURAL QA 05-2023-28* > > Q1 Why do airliners have to fly at 250 knots when they are > below 10000 feet? > > A1 Vishnu Ravi, Aviation Enthusiast | Content Creator 20h > > Aircraft operating below 10,000 feet are required to maintain a speed of > 250 knots for various important reasons. Let's delve into these reasons in > detail: > > *Regulations: As per the guidelines outlined in 14* CFR 91.117, it is > prohibited for any individual to operate an aircraft below 10,000 feet mean > sea level (MSL) at an indicated airspeed exceeding 250 knots, unless > specifically authorized by the Administrator. > > *Safety: The establishment of this speed limit is* primarily aimed at > ensuring the safety of all aircraft in the vicinity. By adhering to the > 250-knot limit, airplanes can effectively maintain an adequate distance > from one another, particularly in congested airspace. This measure plays > a crucial role in preventing potential mid-air collisions and maintaining > overall aviation safety. > > *Noise Reduction: Operating at a lower speed* significantly contributes > to the reduction of noise pollution, especially in densely populated areas > surrounding airports. By reducing the velocity of aircraft, the > disturbance caused by engine noise is mitigated, resulting in a more > harmonious environment for nearby residents. > > *My note- Telecom department was having a* training centre at > Meenambakkam, somewhat close to airport. While attending/ taking class, due > to heavy noise from aircrafts, it was customary to keep silence than > teaching. Now the BSNL is conducting much training for those requiring > employment in all fields, not only for BSNL. > > *Enhanced Fuel Efficiency: Lowering the speed* during flights below > 10,000 feet also promotes fuel conservation and emission reduction. By > adopting a reduced pace, airplanes can optimize their fuel consumption, > leading to greater efficiency and minimized environmental impact. > > It is important to mention that certain aircraft possess the capability to > exceed 250 knots indicated airspeed below 10,000 feet. However, these > aircraft are not allowed to do so unless expressly authorized by the > Administrator. Furthermore, *in instances where air traffic control > assigns a speed higher than 250 knots* while an aircraft is at or above > 10,000 feet MSL, and subsequently instructs a descent below 10,000 feet > MSL, the aircraft must decelerate to 250 knots before initiating the > descent. > > Q2 Exactly what do we need to filter out of our tap water? > Certainly not everything in tap water is harmful, is it? > > A2 Keith Odom, Former Plant Operator - Water & Waste Water. At > CDCR - Pelican Bay (1997–2003)4y > > The ugly actual truth is that you don’t actually need to filter anything > out of most tap water! > > There has always been a big element of 'scam' to the whole consumer > filtration thing. But people want to feel like they are doing something for > the good of their health. And business is willing to make money selling > filters and bottled water. So there you go. > > *I was a water treatment professional. I drink my* water straight out of > the tap. Because I know that the other water treatment professionals of the > world take a lot of pride in doing their jobs well. > > And the designers and engineers who made the plans are exactly the same. > We spend our time making sure that the water is safe to drink. > > That said… occasionally there are problems or situations where the water > is not safe to drink. > > Very old water systems that have not been maintained well can be a > problem. The pipes can start leaking and bad microbes can infiltrate into > the water. > > I had an aunt who had to either buy bottled water or boil the tap water. > Because she lived way out in the country, her tap water was being pulled > straight off a nearby farm water canal. Canals can harbour bad microbes. > > In Detroit a couple of years ago there were big problems with tap water > causing disease. A huge scandal. Detroit had changed the source of where > they got their water from. *The new source, which was a nearby river, had > unsafe water*. And, the Water Plant managers, and more importantly, the > City business managers, didn’t want to face up to the problem, which they > did know about, and the huge money expenses required to fix the problem. So > they lied and denied and lots of people drank tainted water. I hope those > managers go to jail. > > *So, at the risk of repeating myself, for most people in most places, > there isn’t anything they need to do extra to filter their water.* > > *My note- While I had training as phone inspector* (1965’s) we were told > only tap water is used for preparing batteries, but in India we use > distilled water as tap water is not pure in India. Water was so pure in > London at that time. > > *During my student days in Kerala (till 1964’s) we used water* from wells > for drinking. It was filtered only during rainy seasons. > > Basic water filtering was only known using charcoal saw dust and sand and > was available in major offices. > > Q3 What fruits are good for diabetics? > > A3 Farhad Rajshahi, Health Tips19h > > *For diabetics, it's generally recommended to choose fruits that are low > in sugar and have a lower glycaemic index (GI).* Here are some fruits > that are considered good choices for diabetics: > > 1. Berries: Strawberries, blueberries, raspberries, and blackberries are > all low in sugar and high in fibre, which can help regulate blood sugar > levels. > > 2. Apples: Apples are a good source of fibre and have a moderate GI. They > also contain antioxidants and vitamins. > > 3. Citrus fruits: Oranges, lemons, limes, and grapefruits are low in > sugar and rich in vitamin C. They also provide fibre. > > 4. Cherries: Cherries have a lower glycaemic index compared to many other > fruits and are packed with antioxidants. > > 5. Pears: Pears are a good source of fibre and have a lower glycaemic > index. Choose fresh pears over canned ones, as canned pears often have > added sugars. > > 6. Kiwi: Kiwis are low in sugar and high in fibre. They also provide a > good amount of vitamin C and other nutrients. > > 7. Avocado: While technically a fruit, avocados are low in carbohydrates > and high in healthy fats, making them a good choice for diabetics. > > Remember that portion control is still important, even when consuming > fruits that are considered good for diabetics. It's best to consult with > a registered dietician or healthcare professional for personalized advice > based on your specific dietary needs and blood sugar management goals. > > Here's some additional information regarding fruits for diabetics: > > *1. Portion control: While fruits can be a healthy part* of a diabetic > diet, it's important to consume them in moderation. Even though they > contain natural sugars, they can still affect blood sugar levels. Be > mindful of portion sizes and consider balancing your fruit intake with > other low-carbohydrate foods. > > *2. Whole fruits vs. fruit juices: Whole fruits are* generally a better > choice than fruit juices. Whole fruits contain more fibre, which can help > slow down the absorption of sugar into the bloodstream. Fruit juices, on > the other hand, can cause a more rapid spike in blood sugar levels due to > their higher sugar concentration and lack of fibre. If you prefer fruit > juice, opt for freshly squeezed or 100% juice options without added sugars, > and consume them in moderation. > > *3. Glycemic index (GI): The glycaemic index is a* scale that measures > how quickly carbohydrates in food raise blood sugar levels. Foods with a > lower GI are digested more slowly, causing a slower and more gradual > increase in blood sugar. Generally, fruits with a low to moderate GI are > better for diabetics. However, it's important to note that the glycaemic > index can vary depending on the ripeness of the fruit and how it's prepared > (e.g., cooked, raw, or blended). > > *4. Individual differences: **The impact of fruits on* blood sugar levels > can vary between individuals. Factors such as overall diet, medication, > physical activity, and personal blood sugar response can influence how > fruits affect blood glucose. > > It's important to monitor your blood sugar levels regularly and work with > a healthcare professional or registered dietician to determine which fruits > work best for you. > > *5. Balanced meals: When incorporating fruits into* your meals, it's > advisable to combine them with other foods that provide protein, healthy > fats, and fibre. This can help slow down digestion and minimize the impact > on blood sugar levels. For example, you could pair a small apple with a > handful of almonds or have berries with Greek yogurt. > > Remember, it's always a good idea to consult with a healthcare > professional or a registered dietician who specializes in diabetes care for > personalized advice tailored to your specific needs and health goals. > > Here are some benefits and advantages of including fruits in the diet of > individuals with diabetes: > > *1. Nutrient-rich: Fruits are packed with essential* vitamins, minerals, > and antioxidants that are beneficial for overall health. They provide a > wide range of nutrients, including vitamin C, potassium, folate, and > various phytochemicals, which can support the immune system, promote cell > health, and help protect against chronic diseases. > > *2. High in fibre: Many fruits are excellent sources of* dietary fibre. > Fibre helps regulate blood sugar levels by slowing down the absorption of > sugars into the bloodstream. It can also contribute to improved digestion, > help control appetite, and support weight management. > > *3. Low in unhealthy fats: Fruits are naturally low in* unhealthy fats, > particularly saturated and Trans fats, which are linked to an increased > risk of heart disease. By incorporating fruits into the diet, individuals > with diabetes can choose a healthier alternative to high-fat snacks and > desserts. > > *4. Hydration: Many fruits have high water content,* which can contribute > to proper hydration. Staying hydrated is important for overall health and > helps support various bodily functions. > > *5. Satiety and weight management: The fibre* content in fruits, along > with their natural sweetness, can help promote a feeling of fullness and > satiety. This can be beneficial for individuals with diabetes who are > looking to manage their weight or prevent overeating. > > *6. Versatility and variety: Fruits offer a wide array of* options, > flavours, and textures, allowing individuals to enjoy a varied and > enjoyable diet. From berries and citrus fruits to tropical fruits and > melons, there are numerous choices available to suit different preferences. > > *7. Healthier dessert options: For those with a sweet* tooth, fruits can > be a healthier alternative to high-sugar desserts. By incorporating fruits > into desserts or enjoying those on their own, individuals with diabetes can > satisfy their cravings for sweetness while consuming essential nutrients > and fewer added sugars. > > It's important to note that the benefits of fruits for individuals with > diabetes can vary depending on individual needs, overall diet, and blood > sugar control. It's recommended to work with a healthcare professional or > registered dietician who specializes in diabetes care to determine the best > approach to incorporating fruits into a balanced diabetic diet. > > While fruits offer many benefits for individuals with diabetes, there are > a few considerations or potential downsides to keep in mind: > > 1. Natural sugars: Fruits contain natural sugars, mainly fructose. > Although these sugars are accompanied by fibre and nutrients, they can > still impact blood sugar levels. It's essential to monitor portion sizes > and be mindful of overall carbohydrate intake to maintain blood sugar > control. > > 2. Glycemic impact: While most fruits have a lower glycaemic index (GI), > some fruits, particularly those that are ripe or overripe, may have a > higher GI. This means they can cause a quicker increase in blood sugar > levels. It's important to consider the ripeness and preparation of fruits > when planning meals and snacks. > > 3. Individual responses: Every person with diabetes may respond > differently to different fruits. Some individuals may find that certain > fruits cause a larger increase in their blood sugar levels compared to > others. It's important to monitor blood sugar levels and observe personal > responses to determine which fruits work well for you. > > 4. Portion control and moderation: While fruits offer health benefits, > it's crucial to consume them in moderation and practice portion control. > Eating large amounts of fruits, even those lower in sugar, can still > contribute to overall carbohydrate intake, potentially affecting blood > sugar levels. Balancing fruit intake with other macronutrients and > considering overall calorie and carbohydrate goals is important. > > 5. Fruit juices and dried fruits: Fruit juices and dried fruits can be > more concentrated in sugar and have a higher glycaemic impact compared to > whole fruits. They can also be lower in fibre content. It's advisable to > limit consumption of fruit juices and dried fruits or choose options > without added sugars and enjoy them in small quantities. > > 6. Allergies or sensitivities: Some individuals may have allergies or > sensitivities to specific fruits. It's important to be aware of any known > allergies or reactions and avoid fruits that may trigger adverse symptoms. > > Remember, it's crucial to work with a healthcare professional or > registered dietician who specializes in diabetes care to create a > personalized meal plan that takes into account your individual needs, > preferences, and blood sugar management goals. They can provide guidance on > fruit selection, portion sizes, and overall dietary considerations for > optimal diabetes management. > > Conclusion: > > In conclusion, fruits can be a valuable and nutritious part of a diabetic > diet. They offer essential vitamins, minerals, antioxidants, and fibre, > making them a healthier choice compared to high-sugar snacks and desserts. > By incorporating fruits into your meals and snacks, you can enjoy their > numerous benefits while supporting your overall health and blood sugar > control. > > However, it's important to consider portion control, monitor your blood > sugar levels, and be aware of the glycaemic impact of different fruits. > While fruits are generally lower in sugar and have a lower glycaemic index > compared to processed foods, individual responses may vary. Personalized > meal planning, moderation, and balancing fruit intake with other > macronutrients are key to maintaining blood sugar control. > > Consulting with a healthcare professional or registered dietician who > specializes in diabetes care is highly recommended. They can provide > personalized guidance, taking into account your specific needs, > preferences, and goals, to help you incorporate fruits effectively into a > balanced diabetic diet. With proper guidance and monitoring, you can enjoy > the benefits of fruits as part of a healthy and diabetes-friendly eating > plan. > > My job is to give you good advice, but you must consult a doctor before > taking my advice. > > Q4 Does powder or liquid laundry detergent work better? > > A4 Colin John Cook, Former Development Chemist at Neschen UK > Ltd (1986–2012)Updated 3y > > I am rather suspicious of liquid laundry detergents, in case it is a > gimmick to get more money out of people for the same necessity of washing > clothes. *There is nothing at all wrong with powdered detergents, and > they worked fine for decades. This is what they contain:* > > 1. Sodium carbonate. This is the main washing agent and is a mild alkali. > > 2. Sodium tripolyphosphate. This is a water softener; without it, calcium > carbonate would precipitate from hard water and cause white flecks on the > washed clothing. > > 3. Sodium dodecylbenzene sulphonate (NaDDBS). This is the detergent that > loosens dirt and emulsifies grease. It is generally supplied let down > slightly with sodium sulphate to give a grainy powder form, since it is > somewhat waxy in pure form. > > 4. Non-ionic surfactant defoamer such as ethylene oxide/propylene oxide > block copolymer. This prevents foam from the NaDDBS. It should be active in > cold water for the newer cold wash powders. Some non-ionic precipitate in > warm water and cause defoaming. Larger amounts of non-ionic will be active > detergents and emulsifiers. > > 5. Proteolytic and lipolytic enzyme. This is the 'biological' component > and will digest body fluids, food stains, etc. > > 6. "Per" salt such as sodium percarbonate, actually a hydrogen peroxide > of crystallisation adduct with a salt. This is the bleaching agent. It can > reduce the colour of stains. On the negative side, bleaches can lighten > some dyes. > > 7. Per salt activator, which is a nitrogen ring compound such as from > cyanuric acid.. This produces oxygen from the bleach. > > 8. Sodium carboxymethyl cellulose. This is a stabiliser for dispersed > dirt, and prevents redeposit ion. It produces a colloidal solution or > particles which limit the mobility of the dirt particles. > > 9. Optical brightening agent.. This fluoresces blue under UV light and > neutralises any slight yellowing of fabrics due to age. Blue and yellow > lights add together to produce white, whereas in subtractive (dye) mode > they make green. > > 10. Optional blue colour specks. Just for show, although they do indicate > what the powder is for. Blue violet dyes used to be used to correct > yellowing. In this case, green is not produced even though the colours are > subtractive because the violet part masks the yellow. > > 11. Perfume. Again, optional, but people expect it and it also indicates > that the powder is a detergent, to make things smell better! > > 12. Free-flow agent. There is a variety of types including powdered > silica gel or magnesium carbonate. These enable the otherwise sticky mix to > flow from the box and into and from the dispenser. > > ** Most washing powders that I know have been 'spray dried'. This gives > them a lighter bulk density so that they flow readily down the chute with > the water current. Plain mixes of these, mainly, powdered ingredients give > dense powders that do not pour easily. > > Whether the important parts of those concepts can be all incorporated into > a liquid, I don't know, but as a formulator I do know that compromises are > often made. > > At least with the gel pods that are sold these days, some of the > ingredients can be kept separate until they are ready to go into action. > > Q5 How is electricity obtained in trains? > > A5 Info Sage, Former Insight Investigator (2018–2022)May 22 > > Electricity in trains is typically obtained through one of two methods: > *overhead > lines (also known as catenary systems) or third rail systems.* > > Let's look at both methods: > > *1. Overhead Lines (Catenary Systems):* > > Many electric trains, especially those used for long-distance travel or in > urban areas, receive electricity from overhead lines. These lines consist > of wires suspended above the tracks. *The wires are energized with > high-voltage electricity, typically alternating current (AC).* > > The train itself has a pantograph, which is a device mounted on the roof > that extends to make contact with the overhead wires. When the pantograph > connects with the wires, it draws the electricity from the overhead lines > and transfers it to the train's electrical systems. This electricity powers > various components, such as the traction motors, lighting, air > conditioning, and other on-board systems. > > 2. Third Rail Systems: > > In some train systems, particularly in urban subway or light rail > networks, ***electricity is obtained from a third rail, which is a > conductor located alongside or between the tracks. The third rail is > typically energized with direct current (DC) at a high voltage. > > The train has a current collector, such as a shoe or a sliding contact > that makes contact with the third rail allowing the train to draw > electricity from it. Similar to the overhead line system, the electricity > is then used to power the train's various systems, including propulsion and > other on-board equipment. > > *In summary, electricity in trains is obtained either through overhead > lines or third rail systems*. The trains use specialized devices, such as > pantographs or current collectors, to draw electricity from these sources, > which is then used to power the train's propulsion, lighting, and other > on board systems. > > *** Cochin metro is using third rail whereas Chennai metro is using > overhead wires. > > It is ensured the O/H line get AC voltage from small substations at > frequent intervals. > > *All the above QA are from Quora website on 27--05- 2023.* > > *Quora answers need not be 100% correct answers.* > > *Compiled **and posted by R. Gopala krishnan, former ITS, on 27-05-2023* > > > > -- > 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/iyer123/1615917958.2245971.1685196801870%40mail.yahoo.com > <https://groups.google.com/d/msgid/iyer123/1615917958.2245971.1685196801870%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/CAL5XZopcx%2BJpnh_A6kL7XhH2%3Da4oN_VZq5v1Ysas2RYW%3DEi_Wg%40mail.gmail.com.
