K.Natarajan
09/07/2019
K.Natarajan
09/07/2019
A click from the Hotel Terrace at Coimbatore …. on the evening of 19th June 2019….Thanks to my Mobile camera
K.Natarajan
21st June 2019
Because the economics of having large oxygen tanks aboard airliners simply doesn’t work out (not to mention that the air quality inside the plane would rapidly become unpleasant if fresh air wasn’t constantly supplied, regardless of the oxygen levels), commercial airplanes have a very clever system installed to solve the problem of ultra-low pressure atmosphere at cruising altitudes.
In most modern airliners (the Boeing 787 Dreamliner not withstanding), outside air is “bled off” from the compressor stage of the turbine engines and eventually piped into the passenger areas. However, a bit of processing is needed first as the compressed air is extremely hot (on the order of nearly 400 degrees Fahrenheit or 200 degrees Celsius) at this stage. Thus, before it enters the passenger compartment, it is first allowed to expand and is run through a heat exchanger and air cycle system to cool it off sufficiently. This system also can work as a heater, with some of the hot air mixed in with the cooled air to regulate cabin temperature.
Once cooled and filtered, the pressurized air, which now has sufficient oxygen density to keep people happily conscious, is piped into the cabin area, usually at levels around 12 psi (about equivalent to atmospheric pressure at 7,000 feet). Why 12 psi instead of something like sea-level pressures of about 14.7 psi? 12 psi is sufficient for the majority of passengers while simultaneously reducing the structural strain on the aircraft itself over something like sea level atmospheric pressures.
As for the air already in the cabin, this is vented out through an outflow valve (or multiple valves in larger aircraft), usually located near the rear of the plane. (FunNote: Before smoking was banned on commercial aircraft, the area around this outflow valve was generally stained dark brown from tobacco smoke.)
This outflow valve opens and closes automatically to maintain a steady pressure inside the cabin, while the entire system is ensuring that fresh air is continually being piped into and eventually blown out of the aircraft. In fact, while many complain of airplanes seeming “stuffy,” this system ensures that all the air in the aircraft is being completely replaced on average every 2-3 minutes. Yes, that means that your car, house or office is likely significantly more “stuffy” than a commercial airplane flying at 35,000 feet.
(Note: the Boeing 787 Dreamliner handles cabin pressurization a little differently, using a modernized version of the old, somewhat inefficient, electric compressor system seen on many older aircraft.)
Unfortunately, sometimes planes lose cabin pressure. Whatever the cause, the loss of pressure (usually set at atmospheric pressures past 14,000 ft) will result in oxygen masks deploying. From here, useful consciousness may only last as little as 5-15 seconds, depending on remaining cabin pressure, which is why it’s critical to immediately put your mask on, rather than helping someone else first. You can help them much better when you’re not unconscious or dead.
So how do these airline oxygen masks actually work? It turns out, the economics of having a centralized oxygen tank to provide even emergency oxygen for passengers likewise simply doesn’t add up. Similarly, having tiny individual pressurized oxygen tanks also isn’t feasible. In fact, these masks aren’t hooked up to any tank or air line at all. So how are you able to breathe oxygen through them?
Science.
While designs can vary slightly, in general, when you pull on the device to place it over your face, the tug on the mask’s lanyard releases a spring-loaded mechanism that sets off a small explosive charge. (Yep.) The resulting spark triggers a mixture of lead styphnate and tetracene to generate heat, which will eventually cause a chemical reaction that produces oxygen for your mask. (This is why they tell you to tug on the mask to get the oxygen flowing- you’ve got to set off the explosive charge to get the whole thing going.)
That’s right. What you breathe through the mask didn’t begin as pure oxygen. Rather, the plane is equipped with numerous small chemical oxygen generators (also known as “oxygen candles,” about the size of a small package of tennis balls) which contain a mixture of mostly sodium chlorate (NaClO3), less than 5% barium peroxide (BaO2) and less than 1% potassium perchlorate (KClO4). When these chemicals are heated by the lead styphnate and tetracene, each undergoes a reaction that ultimately results in a fair bit of filtered, life sustaining oxygen running through the tube to you.
Of course, you might also smell a faint burning odor, but this is nothing to be alarmed about; it just assures you that the system is working. In fact, if the plane is actually on fire, the masks usually won’t deploy, so as not to make the fire worse with the extra oxygen.
This brings us to the question of why the plastic bag on the breathing apparatus won’t necessarily inflate as you’re using the device. More than just cosmetic, the bags serve as something of a reservoir for oxygen. If you aren’t taking a breath at all (and have a good seal with the mask tight against your face) the bag keeps the precious, continuously flowing oxygen from escaping into the thin air around you, enabling more of the collected oxygen to be taken in when you do take a breath. When this is happening, or you are breathing out with the valves on the mask releasing much of the used air, the bag may begin to inflate as oxygen collects. When you breathe in, it will deflate.
So why won’t it always inflate at least a little to show its working? To begin with, you may not have a great seal with the mask on your face, particularly if you have facial hair. This will allow any produced oxygen (and air you exhale) to more readily escape. (As long as the mask is reasonably secure on your face, this should still provide you with sufficient oxygen to get by on as long as the plane isn’t flying above 40,000 feet and the pilot does his or her job and gets the plane down below 10,000 feet as rapidly as safely possible.)
Even if you have a good seal, however, the rate at which the oxygen is generated is often not enough to fully inflate the masks’ bag before you take deep, potentially panicky breaths, deflating it. This is simply because the oxygen generation isn’t on-demand (for the passengers anyway), but simply a continuous-flow production of oxygen.
Despite the potentially slow production, the chemical oxygen generators do provide oxygen at a sufficient rate to sustain passengers, generally designed such that peak oxygen production occurs right away (when the plane may be at very high altitude) with the oxygen production rates tailing off over the course of approximately 12-20 minutes before the system burns itself out.
This should be long enough for the pilots to get the plane low enough so that the air pressure is high enough for (relatively) normal atmospheric breathing. And if you’ve ever been lucky enough to be in this sort of situation, you know that those pilots can get the plane from altitudes like 35,000+ feet to safer atmospheric levels alarmingly quickly in an emergency; while it may not be literally true, it at least can seem like roller coasters have nothing on them, which is a good thing in this case.
Bonus Fact:
Source…..www.today i found out.com
Natarajan
If you’re flying to Sikkim, the nearest airport is at Bagdogra, in West Bengal, nearly 124 kms from the state capital, Gangtok.
The Pakyong airport now puts Sikkim on India’s aviation map. It is one of the five highest airports in the country and was built over several years, costing an estimated Rs 350 crore.
“The Pakyong (Gangtok) Airport at Sikkim got a license today for scheduled operations. It’s an engineering marvel at a height of more than 4,500 ft in a tough terrain. Will pave way for direct air connectivity to our lovely state of Sikkim, giving a boost to tourism & economic growth,” tweeted Civil Aviation Minister Suresh Prabhu.
Tourists, migrant workers and locals will soon fly on the low-cost airline SpiceJet, after it was granted permission to fly to Pakyong from Kolkata under the Centre’s regional connectivity scheme.
The picturesque runway of the Pakyong Airport in Sikkim. Image Credit: Soumen Mukherjee
1. The Pakyong airport in Sikkim is spread over 990 acres and is the first greenfield airport to be constructed in the north-east region of the country.
2. Over the years, several landslides near the runway resulted in work being suspended twice, but it was finally constructed and earlier this year, a fixed-wing 19-seater Dornier 228 IAF aircraft landed on the runway.
3. The airport is considered an engineering marvel because of its terrain. It is stationed at more than 4,500 feet and lies snugly between the Himalayas.
4. It is around 30 km from Sikkim’s state capital, Gangtok, and is located around 60 km away from the Indo-China border, giving it strategic importance. It is believed that the Indian Air Force (IAF) will be able to land various types of aircraft on the airport’s runway.
5. Until now, Sikkim was the only state in the country which did not have an airport. The Pakyong airport is the 100th functional airport in India.
According to MoneyControl, as per a previous proposal by the Ministry of Home Affairs, due to its “strategically important” location, the security of the Pakyong airport should be handled by the Central Industrial Security Force (CISF). The CISF is a professional aviation security force that handles 59 airports across the country.
The new airport will be an excellent opportunity for those of you who haven’t yet experienced this beautiful mountainous abode.
Source………Rayomand Engineer in http://www.the betterindia.com
Natarajan
Founded in 1943 by Swede Ingvar Kamprad and headquartered in the Netherlands, furniture giant IKEA makes revenue worth €38.3 billion with 411 outlets in 49 countries.
And while the numerous conversations CEO of IKEA India Juvencio Maeztu had with Indian biggies may be credited for the 2012 plan to finally take shape, there is a backstory many aren’t aware of. It’s how the 48-year-old bossman who relocated from London to Delhi’s NCR Region found a home away from home. All over a cup of masala chai.
It was 2012. Juvencio Maeztu had only arrived in India as the CEO of IKEA India. The switch from London to the bustling city of the National Capital Region was anything but easy.
Speaking to the Economic Times, the 48-year-old recalls, “I had many concerns. I am too small, and India is too big. Could I understand India, its size, its complexity and diversity? Will my European roots constrain me?”
His mind was clouded with doubts, but he had far more important matters to attend. For instance, his morning appointment at the FRRO (Foreigners Regional Registration Office) in Delhi. And he needed a passport-size photograph.
And so, his driver drove through the lanes of NCR, before making a halt at one of the many hole-in-the-wall photography studios. The one they stopped at was run by an old gentleman.
He just had to take a photograph and be on his way. How much time could it possibly take? He couldn’t be late for his appointment.
And so, the CEO entered the shop and asked the man, “Can you take my photo?”
“Yes,” came the reply.
“How long will it take?” Maeztu asked hesitantly
“Five minutes,” the man said.
The photo was clicked. But the wait for the 5 min – ‘N’ copies of the photograph dragged on for over 15 minutes. The printer was old and dusty, takes time to warm up, the man told him.
But he was quick to offer him – “Masala chai?” he asked.
“No” came the curt reply. Even as the man struggled with the printer, he kept persuading Maeztu to drink a cup of chai. An exasperated Maeztu gave him a brusque, “No”.
It was at this time that the photographer asked, “Sir, what’s the point of life if you cannot enjoy a masala chai for five minutes?”
“Something clicked,” Maetzu told the publication. He moved to take a seat, drank the cup of masala chai. The appointment was forgotten, and the two men chatted for over an hour that day.
He may have missed his FRRO appointment, but Maetzu says, “That was the moment I connected with India. It was a turning point.”
He had finally found a home away from home.
While land has been acquired in Gurugram, Bengaluru and Mumbai, the retail stores will only come up in the next few years. With a staff strength of 535 and an investment of Rs 10,500 crore, the furniture giant is here to make it big reported the publication. The current number of employees though is estimated to be around 950 people directly, about 1500 at its store in Hyderabad and aims to hire another 15,000 employees as it expands its operations.
“We are here for the long term. We think of 100 years when we think of our strategy. I have taken no shortcuts. More importantly, I have had no pressure (from the headquarters) to take shortcuts. In the next 100 years, the sheer size of India makes it important. There are other super big reasons. India is challenging us to find better ways to do business. This is a market you need to learn and not come into with an attitude that you know everything,” he said.
The vision is to also have over 25 stores and 20,000 employees in India by 2030.
The report adds how India is the first market where IKEA is rolling out a multi-channel retail online and offline strategy from day one. It is also planning to explore the use of eco-friendly raw materials like bamboo, coconut waste, water hyacinth and recycled PET.
Apart from working with over 80,000 farmers to boost cotton production, it is also helping skill 1,200 women artisans with the UNDP under its programme ‘Disha’ and boost employment from underprivileged communities.
Seems like a journey that began with one cup of masala chai came a long way after all!
“மழை நீர்… உயிர் நீர்…”, “மரம் வளர்ப்போம்; மழை பெறுவோம்…” இப்படி மழை நீருக்காக ஏராளமான வாசகங்கள் பெரும்பாலும், வாகனங்களின் பின்புறம்தான் எழுதப்படுகின்றன. கான்கிரீட் காடான நகரங்களில் மழை நீர், சாக்கடையிலும், கடலிலும்தான் கலக்கின்றன. பெய்யும் மழை நீரைச் சேகரிக்க முடியாமல், கோடை காலத்தில், தண்ணீர் பஞ்சம் ஏற்பட்டு, கேன் தண்ணீரை நம்பி காலத்தை ஓட்டி வருகிறோம்.
கோவையில் இந்தாண்டு கோடை காலம் முதலே நல்ல மழை பெய்து வருகிறது. கோவையில் ஓராண்டில் பெய்யும் சராசரி மழை அளவு 620 மி.மீட்டர். இந்த நீரைச் சேகரித்தாலே குடிநீர் பஞ்சம் எட்டிக்கூட பார்க்காது. ஆனால், பெய்யும் மழை நீரைச் சேகரிக்க முடியாததால், கடந்த சில ஆண்டுகளாக, கோவையில் கோடை காலத்தில் கடுமையான தண்ணீர் பஞ்சம் ஏற்படுகிறது. நிலத்தடி நீர் மட்டமும் கணிசமாகக் குறைந்துவிட்டது.
இந்நிலையில், கோவையில் மழை நீரைச் சேமிப்பதற்காக, பொது இடங்களில், மழைநீர் சேகரிப்புக் கிணற்றை தன்னார்வலர்கள் அமைத்து வருகின்றனர். அதன்படி, இந்தியாவின் “மழைநீர் மனிதன்” என்று அழைக்கப்படும் சேகர் ராகவனின் ஆலோசனைப்படி, ரேக் அமைப்பு, கோவை குளங்கள் பாதுகாப்பு அமைப்பு மற்றும் சில நல்ல உள்ளங்கள் உதவியுடன், கோவை மாநகராட்சியுடன் இணைந்து மழைநீர் சேகரிப்பு கிணறை அமைத்து வருகின்றனர்.
மழைநீர் சேகரிப்பு கிணறு
மழை நீர் அதிகளவில் வீணாகக்கூடிய பொது இடங்களில், குழி தோண்டி, அதில் கான்கிரீட் ரிங்கை அமைத்தால் போதும். உதாரணத்துக்கு எட்டு அடி குழிதோண்டி, அதில் தொட்டி போல, நான்கு அடி விட்டமுள்ள, காங்கிரீட் ரிங்கை இறக்கி வைத்தால்போதும். சராசரியாக எட்டு அடி ஆழமுள்ள குழியில் 3,000 லிட்டர் நீரை சேமிக்கலாம். இதில் சேமிக்கப்படும் நீர், கொஞ்சம், கொஞ்சமாக நிலத்தில் இறங்கும். இதன் மூலம், சுற்றுவட்டாரப் பகுதிகளில் நிலத்தடி நீர் மட்டம் உயரும். சென்னையில் வெற்றி பெற்ற இந்த மழைநீர் சேகரிப்புக்கிணறுகளை, கோவையில் முதல்கட்டமாக, குறிச்சி பகுதியில் மாநகராட்சிக்கு சொந்தமான ரிசர்வ் சைட்டிலும், துடியலூர் பகுதியிலும் நடைமுறைப்படுத்தியுள்ளனர்.
இதுகுறித்து சேகர் ராகவன், “பூமிக்குள் நீர் இறங்குவதற்கு, 10 முதல் 15 அடி ஆழத்துக்கு குழி தோண்டலாம். நமக்கு தகுந்தாற்போல் ரிங் அமைத்துக் கொள்ளலாம். ஆண்டுக்கு ஒரு முறை மட்டும் இதைச் சுத்தம் செய்தால் போதும். இதை வீடுகளிலும் அமைக்கலாம். தெருக்களின் ஓரமாகவும் அமைக்கலாம். நீர் சேமித்து வைக்கும் தொட்டியாக இதைப் பார்க்கக் கூடாது. நீரை நிலத்தடிக்கு அனுப்பி வைக்கும் திட்டமாகத்தான் பார்க்கவேண்டும். சென்னையில் பல இடங்களில் இந்த மழைநீர் சேகரிப்புக் கிணற்றை அமைத்துள்ளோம். இதன் மூலம் வெள்ள அபாயத்தையும் தவிர்க்கலாம். நிலத்தடி நீர் அளவையும் அதிகரிக்கலாம். குறிப்பாக, அடுக்குமாடி குடியிருப்புப் பகுதிகளில் இதுபோன்ற கிணறுகளை அமைப்பது மிகவும் நல்லது. நிலத்தடி நீர் என்பது, வங்கியை போன்றது. அதில் தண்ணீரைச் செலுத்தினால்தான், மீண்டும் அதில் இருந்து, தண்ணீரை எடுக்க முடியும். 10 அடி ஆழம், 3 அடி காங்கிரீட் ரிங்குடன் கூடிய மழை நீர் சேகரிப்பு கிணறை அமைக்க 12 ஆயிரம் ரூபாய் ஆகும்” என்றார்.
ரேக் (Raac) அமைப்பின் ரவீந்திரன், “தற்போதைக்கு, பெரும்பாலான பகுதிகளில், மழை நீரைச் சேகரிப்பதற்காக, 200 அடிக்கு போர் போட்டு, ஆறு அடிக்கு குழித் தோண்டி, அதில் கற்களை போடுவார்கள். இதற்கு 75 ஆயிரம் ரூபாய்வரை செலவாகும். எல்லோராலும் இதை அமைக்க முடியாது. அவற்றை பராமரிப்பதும் கடினம். ஆனால், மழை நீர் சேகரிப்புக் கிணறுகளை அமைக்க அவ்வளவு செலவு ஆகாது. இதை, பராமரிப்பதும் மிகவும் எளிது. 15 ஆயிரம் ரூபாய் செலவுசெய்து ஓர் கிணற்றை அமைத்தால், அதன் மூலம் 15 ஆண்டுகளுக்கு மழை நீரைச் சேமிக்கலாம். பொது இடங்களில் மழை நீரைச் சேமிப்பதற்கு இது மிகவும் எளிதான வழி. இதுதொடர்பாக, மக்களிடையே விழிப்பு உணர்வும் செய்து வருகிறோம். மழைக்காலம் முழுவதுமே மழை நீர் சேகரிப்புக் கிணற்றை அமைக்கத் திட்டமிட்டுள்ளோம்” என்றார்.
சமூக ஆர்வலர் டிம்பிள் கூறுகையில், “சென்னை அண்ணாநகரில் என் உறவினர் வீடு உள்ளது. அவர்களுடையே தெருவே லாரி தண்ணீரை பிடித்துக் கொண்டிருக்கும். ஆனால், இவர்கள் பிடிக்க மாட்டார்கள். அப்போதுதான், மழைநீர் சேகரிப்பு கிணறு குறித்துத் தெரியவந்தது. அப்போதிலிருந்தே, இந்தத் திட்டத்தைக் கோவைக்கு கொண்டு வரவேண்டும் என்று ஆசை இருந்தது. எங்களது அப்பார்ட்மென்ட் அருகே, இப்படி வீணாகும் மழைநீரை பார்க்கும்போது, எனக்கு வருத்தமாக இருக்கும். பின்னர், சேகர் ராகவனுடன் ஆலோசித்து, எங்களுடைய அப்பார்ட்மென்ட் அருகே உள்ள ரிசர்வ் சைட்டில் கிணறு அமைத்தோம். 2,500 சதுரடி பகுதியில் பெய்யும் மழை நீர், இதில் சேமிக்கப்படும். கோவை முழுவதும் இதுபோன்று 44 ஆயிரம் குழிகள் அமைக்கலாம் என்கின்றனர். அப்படி அமைக்கும்போது, நிலத்தடி நீரின் அளவு ஒன்பது மீட்டர் வரை அதிகரிக்கும். எனவே, பள்ளிகள், அரசு அலுவலகங்கள், ஷாப்பிங் மால்கள் போன்ற பகுதிகளில் இதுபோன்ற கிணறுகளை அமைக்கலாம். அந்தப் பகுதிகளில் உள்ள மக்கள் இணைந்து, தங்களின் பங்களிப்பில்கூட இதுபோன்று குழிகளை அமைக்கலாம்” என்றார்.
மழை பெய்வதற்கு முயற்சி செய்யாவிடினும், குறைந்தது பெய்யும் மழை நீரையாவது சேமிக்க முன் வருவோம்…!
Source….. http://www.vikatan.com
Natarajan
A typical Pakistani truck driver spends more time with his truck than he does with his wife. Which explains why he wants his 10-ton six-wheeler to look like a new bride.
These trucks plying across Pakistan’s national highways and the neighboring country of Afghanistan are distinctively ostentatious. The entire trucks, from top to bottom, are a riot of colors. Lavishly painted panels containing a mosaic of birds, flowers, landscapes, saints, and actresses in hyper-saturated color palette adorn the exterior, while plastic flowers, draped beads, mirrors, ribbons and velvet grace the interior. The cabin is crowned by a custom built wooden prow wrapped in more kitschy artwork, while a string of metal bells dangle from the chassis all round the periphery. When the truck is in motion, these bells clang against each other like a new bride’s ghungroo. This is where the nickname “jingle trucks” come from—coined by US troops deployed in Afghanistan.
Photo credit: ISAF Public Affairs/Flickr
And it isn’t just trucks alone. Passenger buses, water tankers, transport vans, rickshaws, and even vendors’ pushcarts are psychedelically decorated with eye-popping colors. It’s like a rolling folk art, “a national gallery without walls, a free-form, kaleidoscopic exhibition in perpetual motion,” as Richard Covington puts it.
The tradition of decorating trucks began sometime in the 1920s with the introduction of the long-distance Bedfords—a British-built truck with rounded cab and seven-feet high paneled sides that was to become the country’s most prestigious and dependable truck for more than half a century. Originally trucks were painted with each company’s logo so that illiterate people could recognize who owned the trucks. Gradually, these logos became more fanciful, flamboyant and competitive. By the 1950s, stylized murals and frescoes had begun to replace them. It was only in the 1960s, as the country’s economy boomed, the decorations became increasingly sophisticated to reflect the growing wealth of the drivers and the rise of a new urban class.
Pimping out a truck this way cost truck owners a small fortune. It isn’t unheard of for a driver to spend the equivalent of a year’s worth, or more, of profits on truck decorations. According to a 2005 article, a basic painting and body job costs a minimum of $2500, equivalent to two years of the average truck driver’s salary. Some spend upwards of $10,000 outfitting their rigs. Unbelievably, many truckers will return to the workshop every three or four years for a full vehicle makeover.
“Truckers don’t even spend so much money on their own houses,” marvels Durriya Kazi, head of the department of visual studies at the University of Karachi. “I remember one driver who told me that he put his life and livelihood into the truck. If he didn’t honor it with the proper paint job, he would feel he was being ungrateful.”
A well-decorated truck also gives customers the impression that it is well taken care of and will, therefore, be a dependable way to transport goods.
Truck painting is also a big business. In Karachi city alone, more than 50,000 people are engaged in this unregulated yet lucrative industry. Family-run workshops comprising of apprentices and highly trained artisans, and small shops selling all manners of outlandish ornaments and accessories crowd around truck yards.
Over the years, however, the business has changed. Now instead of meticulously hand painting each truck, mass produced stickers and adornments are used.
“Truck decoration is not stagnating; it is dead,” laments R M Naeem, an assistant professor at the National College of Arts, Lahore. “This is because truck painters treat their work as a source of livelihood. They do not have the time or the luxury to innovate; they repeat the same old patterns, images and icons over and over again.”
However, thanks to artists like Haider Ali, who gave a Ford van a jingle-truck-style makeover a couple of years ago in a parking lot in Pasadena, California, and other painters, it’s unlikely that this quintessentially Pakistani craft is going to die out any time soon
Source……..Kaushik in http://www.amusingplanet.com
Natarajan