When and how were the Himalayas formed?

The Himalayas or Himalaya is the tallest mountain range in the world. Literally meaning the 'abode of snow' in Sanskrit, this natural wonder has the third largest deposit of snow and ice, after the poles. The Himalayas extend for some 2400 km, spanning Pakistan, India, Nepal, China and Bhutan. It is home for nine of the ten tallest peaks in the world, including Mount Everest, the tallest peak in the world which measures 8848 m. The mountain range is also the source of some major rivers in the world, such as Indus, Ganges and Bhramaputra. Himalaya serves as a natural border of India, and has played a big role in sketching the culture and lifestyle of the subcontinent. Himalaya has great significance in Hinduism and Buddhism.

Despite its amazing superlatives, the Himalaya is comparatively a younger mountain range. In fact, it is one of the youngest, with an age estimated to be around only 50 million years. A lot of research had gone into understanding the formation of Himalayas. It is believed to have been formed as a result of a collision between two tectonic plates, Indo-Australian and Eurasian.

According to German scientist Alfred Wagner's Theory of Continental Drift, there had been only a single large continent named Pangaea. The landmass then began to break up and move towards and from each other. About 200 million years ago, India was an island floating off the coast of Australia. It was separated from Asia by the Tethys ocean. As Pangaea began to break, the Indian plate began to drift towards Asia in North. It traveled more than 6000 km in a period of 150 million years before finally colliding with the Eurasian plate. The Tethys ocean went out of existence, having been closed by the Indian plate.

When collided, neither of the plates could be subducted because their crusts were of low density. Instead they were folded and faulted along the threshold, forming the Himalayan mountain range. The mountain grew over millions of years, assuming the current form.

The Indian plate is still drifting towards North, with a speed of 67 millimeters per year. As a result, the height of Himalaya is also increasing, with a rate of 5 millimeters per year, though impeded by erosion and gravity. The movement of Indian plate makes the area susceptible to seismic activities. Recurring earthquakes are evidence of the movement, and it will continue to rise in future years. Hence, the area is becoming more dangerous for living. Add to that unscientific construction practices, a catastrophe is waiting to happen.

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What is the difference between concrete and cement?

Cement and concrete are two terms people often get confused with and use out of places. People often say ‘cement sidewalk’ or ‘cement mixer’ but the proper terms are ‘concrete sidewalk’ and ‘concrete mixer’. While it may seem harmless using these words interchangeably, it is still technically incorrect. Even though both cement and concrete are construction materials, they are two distinct products.

The cement is actually one of the ingredients of the mixture we call concrete. It is primarily made up of lime and silica. Those two materials constitute for about 85% of cement. Other ingredients include calcium, iron, aluminum and a few others. These materials are mixed and heated in large kilns to very high temperature, ranging from 2,700°F to 3000°F, to form a product known as clinkers. Clinkers are small pellets which resemble marbles. These are later ground into a finely powdered form and gypsum is often added. The final product is what we call cement. When water is added to cement, a chemical process takes place, allowing it to harden. The cement acts as a binding product that helps to hold the ingredients of concrete together.

Cement is basically divided into two types; hydraulic and non-hydraulic. Hydraulic cement uses water to start a chemical reaction and hardens irrespective of the water content and becomes water resistant. This is suitable for wet conditions and underwater structures. Non-hydraulic cement, on the other hand, doesn't harden when mixed with water which makes it unsuitable for most conditions.

The most prevalent type of cement is the Portland cement or Ordinary Portland Cement (OPC). Portland cement is a generic name for the hydraulic cement used in construction. It was developed by Britishman Joseph Aspdin in 18th century. Portland cement itself is classified into 8 types, according to specifications.

Concrete is actually a mixture of cement, water and other aggregates. The aggregates include crushed mostly chemically inert materials like stones, gravel and sand. The amount and type of aggregates vary according to application of concrete. They usually make up 60% to 80% of the mixture. Cement constitute for up to 15% of the total mass of concrete and the latter cannot be made without the former. The ratio of water to cement is very important, as it determines the strength of concrete. Too much water will weaken the mix.

Concrete is one of the most used construction materials, due to its strength, durability and resistance to fire and water. It gets stronger over time because of the continued hardening.

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How did Africa get its name?

Africa. The so-called civilized people call this landmass 'dark continent'. Yet what many of them forget is that the man was born here, thousands of years ago. The great Egyptian civilization flourished here. Africa is the second largest and second most populous continent on Earth. It accounts for the 15% of the total human population in the world. It is home for unparalleled ethnic, linguistic and cultural variety and biodiversity.

The origin of the name Africa has been under dispute for a long time. Like many other things, the historians haven't been able to agree upon its formation. Various historians and writers have proposed different hypotheses regarding the way the continent went on to be known as Africa. Many of these are just proposals without much historical evidence to back up themselves while others are fairly reasonable.

According to the 1st-century Jewish historian Flavius Josephus, the continent was named for Afer, the grandson of Abraham and a companion of Hercules. Josephus claimed that Afer's descendants had reached as far as Libya.

Another assumption is that the word Africa comes from the Latin root aprica meaning 'sunny' or the Greek word aprike meaning 'without cold'. The first one was also suggested by Isidore of Seville in his book Etymologiae. There is also a Phoenician word, faraqa, which means separation or diaspora from which the land might have gotten the name. It is supported by the presence of similar sounding words in some African languages. There is also a Phoenician word, pharika, meaning fruit, considered to be the source of the word Africa.

One of the most popular hypotheses about the origin of the name Africa is linked to the European invasions. The name is believed to have derived from what the Romans called the native people south of the Mediterranean. The word might have stemmed from the Latin word afri, used to refer the Berber tribe Aourigha. The latin suffix -ica is used to denote a landmass as well. The name is also supposed to be linked with the Hebrew word afar, meaning dust. Adding the suffix -ica, it might mean the land of dust.

Even though the word was initially used to denote the Libyan land, as the understanding of Europeans about the geography of Africa grew, it went in to be used for the entire continent. Since the word is a European construct, many eminent Africans, including author Wole Soyinka, have proposed to drop the use of the word, replacing it with appropriate native words.

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How does breathing into a paper bag help hyperventilation?

Hyperventilation is the state in which the rate of alveolar ventilation of carbon dioxide is greater than the body's normal production rate of the gas. It happens when one gets very excited or stressed. Sometimes, people also voluntarily hyperventilate, usually swimmers and yoga practitioners. Involuntary hyperventilation is triggered by a variety of reasons, including respiratory disorders, over physical activity, reduced air pressure and panic attacks.

One long-used technique to help with hyperventilation is breathing into a paper bag. Many doctors around the world have been suggesting this method to their patients for a long time. The paper bag has almost become a readymade solution for hyperventilating like bandage for wound.

The question is how breathing into a bag help with the rapid breathing. To understand that we have to know what happens when we hyperventilate and the mechanism of blood. The pH value determines the acidity of a fluid. A value of 7 in the pH scale means neutral. A value below 7 means acidic and higher than 7 indicates basic. The normal pH value for blood is 7.4, meaning it to be slightly basic.

When we hyperventilate, we take in more oxygen, and the blood gets more basic. The level of carbon dioxide in blood falls, a state known as hypocapnia. Carbon dioxide is carried by blood in the form of bicarbonates. To compensate the drop of carbon dioxide, the hydrogen ions in blood combine with the bicarbonates to free more carbon dioxide. This would result in the loss of hydrogen ions and further increase of alkaline nature of the blood. It is known as respiratory alkalosis. This leads to several problems like constricting of blood vessels and reduction in calcium levels in blood. People would feel dizziness, headache and seizures.

The idea behind breathing into a bag is re-breathing our exhaled carbon dioxide. When the carbon dioxide enters the bloodstream, it will balance the pH value.

Despite its widespread practice, the latest studies have come up with strong advice against the technique of breathing into the bag. The main reason for such a move was the ambiguity in the matter. Often the symptoms of asthma and heart attack get confused with those of hyperventilation. In those times, breathing into a bag can raise the level of carbon dioxide in blood and it could be deadly. There have been a number of such cases in the recent past. Many doctors are now recommending alternative breathing exercises or using an open tube instead. Those who rely on paper bag method are advised not to do it continuously.

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How does sugar make you fat if there is no fat in it?

One of the first things a doctor say to a fat person is the need to cut down the sweet things. Many of you would have thought as well; how does sugar make me fat?

First of all, our body needs sugar to survive. It is a significant part of our metabolism. We get the energy for our daily activities from sugar. There are different types of sugars, including glucose and fructose. Our body produces glucose and uses it for energy. But the sugar in the food we take in contains mainly fructose. It can only be processed by liver cells.

Too much of sugar is certainly harmful for us. Despite not having any fats, there are a number of ways sugar can make one fat.

As mentioned earlier, fructose is metabolized by liver. When we consume more sugar than necessary, the additional amount of sugar is converted by the liver into fatty acids. They get absorbed into the bloodstream, and are stored in various parts of the body, including the stomach, breasts, hips, and butt. These fatty acids later gradually enter our organs such as heart, liver, and kidneys triggering various health problems.

Another way sugar makes one fat is linked with insulin. Insulin, produced by pancreas, is a key hormone that regulates our metabolism. Whenever we consume sugar, insulin is produced to compensate it. The hormone has a few functions like sending signal to peripheral cells like muscles to absorb glucose. When we eat more sugar, the insulin production also goes higher. The other duty of insulin is to inform fat cells to take more fat from bloodstream. So, when insulin is produced in high levels, more glucose gets turned to fat and stored in our body. This also causes our energy levels to drop and makes us hungry, even though we have had enough food. This makes us eat even more and triggers an unhealthy cycle.

Sugar also makes us fat with the effects on the hormone named leptin. Leptin is produced by fat cells. The more fat we have, more leptin is secreted. Our brain determines whether we are hungry or not by checking the leptin levels. Constant eating of sugar produces more leptin and the brain eventually becomes resistant to leptin levels. It means it will be unable to decide we had enough food and keeps us hungry. We would eat more and trigger the aforementioned processes continuously. This is the reason why fat people eat more and keep on getting fatter. Not because they need more food, but because they feel hungry even when their body has had enough food.

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How is maximum occupancy of a building is calculated?

The calculation of maximum occupancy of a building has a significant place in the hazard management. The idea is increasingly influencing new construction methods.

The maximum occupancy of a building is calculated primarily based on two factors. One is the number of available exits in the building and the other is the use of space. The International Building Code has laid down some rules regarding the maximum occupancy of an area. IBC is a model building code developed by the International Code Council (ICC).

As per the definition given by IBC, an exit is a continuous and unobstructed path of vertical or horizontal egress travel from any occupied portion of the building or structure to a public way. Usually, the doors from kitchen and unused rooms are not considered exits.

When calculating the occupancy figure for a building, the two following calculations are used.

1. Floor space factor – The number of persons who can safely reside in the premises. Number of people = Floor area (m²) / Occupant density
2. Exit factor – The width and capacity of the exit routes to allow people to escape safely.

Whichever the less between these figures is the maximum occupancy of a building.

According to the building regulations, the occupant density varies depending on the nature of a building. As per the IBC recommendations, a standing/bar area should have an occupant density of 0.3 M²/person while a shop area could have 2 M²/person and an office area must have 6 M²/person.

Thus, for a bar with an area of 300 M², the maximum occupancy will be 1000. At the same time, an office space with the same area would have a maximum occupancy of 50 as per the floor space factor.

Now we consider the exit factor. As per the recommendations, the ideal width of an escape route or exit is 1050 mm. In any case, it should not be less than 750 mm. An exit with a width of 1050 mm can accommodate 200 Persons in normal conditions. An additional 15 Persons can be accommodated per every 75 mm. If the premises have multiple exits, the wider one is considered to be unavailable. Suppose the above mentioned bar has an exit of 1200 mm width and three exits 1050 mm wide. The total number of persons the exits can accommodate will be 600. Since it is the smaller figure, the maximum occupancy of the premises will be 600.

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What is Root Beer? What is its history?

Soft drinks have a significant part in American life. Root Beer is particularly notable among them, loved by people of all generations. The root beer is a carbonated sweet beverage very similar to birch beer. It is more popular in the North American continent. The drink is traditionally made from the root or bark of the sassafras tree (Sassafras albidium) or the vine smilax ornata (sarsaparilla). As with any other food, it also has various forms, in accordance with local recipes. In addition to sassafras roots, some of the most common ingredients of root beer are vanilla, wintergreen, ginger, coriander, molasses, cane sugar, licorice root and black cherry.

The modern root beer is characterized by sweetness and foamy nature, and is normally devoid of alcoholic content. The amount of caffeine varies, sometimes entirely lacking.

The precursors of root beer are believed to have appeared in the 16th or 17th century. But even before that the Native Americans had been using beverages made from sassafras roots for culinary and medicinal purposes. With the arrival of Europeans, their small beer tradition in which fermented beverages were used for medicinal purposes had an influence in American culture as well. These drinks were made from various herbs and roots of trees and had low alcoholic content. They included birch beer, sarsaparilla beer and ginger beer.

The credit of marketing root beer commercially for the first time goes to pharmacist Charles Elmer Hires from Philadelphia. There are different versions of the tale about how he invented the recipe for his drink in the 1870s. His version of root beer was first introduced to public at the Philadelphia centennial Exposition in 1876. He named his drink 'Hires Root Tea' and called it the 'great health drink'. He later changed the name to root beer to market in the coal mines of Pennsylvania. Hires began to bottle the drink in 1886 and made a good business. By 1890s, root beer was very popular in America. In 1898, Barqs, one of the competitors of Hires, came up with a version of the beverage made from sarsaparilla which became very popular as well.

Now numerous versions of root beer are sold in America. While sassafras root is used in traditional root beers, commercial products use artificial flavors mainly because the oil of sassafras is carcinogenic. A&W Root Beer, founded by Roy Allen in 1919, is the bestselling brand of the beverage today.

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