Wednesday, March 29, 2017

Uses and Problems of Hydrocarbons

A hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. The hydrocarbons are the most broadly used organic compounds known, and are quite literally the driving force of western civilization. The greatest amounts of hydrocarbons are used as fuel for combustion, particularly in heating and motor fuel applications. The primary components of natural gas are methane and ethane. We are all familiar with the use of propane in gas barbecues, lanterns, and as a fuel for internal combustion engines and heating systems. Butane is also a readily available fuel, familiar to everyone in the form of the pocket lighter.
With pentane, the saturated hydrocarbons enter the realm of room-temperature liquids. This makes them useful as organic solvents, cleaners, and transport fuels. Petrol (Gasoline) for internal combustion engines in cars, trucks, tractors, lawnmowers, and so on, is rated in combustion properties relative to octane. It is in fact a combination of liquid hydrocarbons ranging from hexanes to decanes. Slightly larger hydrocarbons are known as kerosene or jet fuel, diesel fuel and heating oil. Still larger hydrocarbon molecules serve as lubricating oils, and greases. Eventually a point is reached at which the materials are solids at room temperature. These are the waxes. Hydrocarbon molecules larger than those of the waxes are the heavy greases and the tars commonly used in roofing applications and highway construction.
Most hydrocarbons are generated from the thermal 'cracking' and fractional distillation of crude oil. Another major source is the industrial alteration of ethanol to produce ethylene. The ethylene so produced becomes a feedstock for the industrial synthesis of other hydrocarbons up to and including polyethylene.

Environmental Problems Associated With the Combustion of Hydrocarbons
Hydrocarbons are burned, or combusted, primarily in engines, power plants and heating systems. Known more commonly as fossil fuels, the hydrocarbons humans burn are coal, natural gas and petroleum products. If combustion were 100 percent efficient and all hydrocarbons contained only hydrogen and carbon, the sole byproducts would be water and carbon dioxide. There are unintended waste products, however, and they cause environmental harm. Even carbon dioxide, which is a natural part of the atmosphere, becomes a pollutant when released in excessive amounts. The environmental liabilities associated with hydrocarbons provide incentives for the development of alternative energy sources.
Polycyclic Aromatic Hydrocarbons
The incomplete combustion of hydrocarbons, especially coal and diesel fuel, causes the release of altered hydrocarbons. These hydrocarbon pollutants, known collectively as polycyclic aromatic hydrocarbons, take a variety of forms. Some are quite toxic, known to harm aquatic life and cause cancer.
Oxides of Carbon, Nitrogen and Sulphur

Incomplete combustion of hydrocarbons also results in carbon monoxide pollution. An odorless, colorless gas, carbon monoxide causes headaches and complications for people with heart disease. Carbon dioxide is always released when hydrocarbons are burned. It is a leading cause of global climate change and the acidification of oceans. Combustion of oil and coal, in particular, causes the release of nitrogen oxides and sulfur dioxide. These oxides combine with water and oxygen in the atmosphere, creating nitric and sulfuric acids, which return to Earth's surface as acid deposition, or "acid rain." Acid deposition harms aquatic organisms and kills trees. Because it makes certain nutrients, such as calcium and phosphorus, less available to plants, it reduces the productivity of ecosystems and farms. An additional problem associated with nitrogen oxides is that they, along with hydrocarbon pollutants, contribute to the formation of tropospheric ozone, a major component of smog.

Tuesday, March 28, 2017

Wine Glasses

Why do people drink wine out of wine glasses?
A great wine glass is plain, colourless, and tulip-shaped. It has a very thin lip and is made of crystal. The tulip shape allows for the concentration and collection of a wine's aroma. The stem allows the glass to be held without warming the wine with your body heat. A thin, properly shaped lip guides the flow of the wine in such a way that the smooth stream touches the most sensitive areas of the tongue. Crystal has a rougher surface than regular glass and therefore helps wine release its aromas as you drink.

Wine glass
A wine glass is a type of glass stemware that is used to drink and taste wine. It is generally composed of three parts: the bowl, stem, and foot. Selection of a particular wine glass for a wine style is important, as the glass shape can influence its perception.

The appropriate way to hold a wine glass, especially when drinking chilled wine, is to grasp it by the stem, in order to prevent the temperature of the wine being affected by body heat.

High quality wine glasses once were made of lead crystal, which has a higher index of refraction and is heavier than ordinary glass, but health concerns regarding the ingestion of lead resulted in their being replaced by lead-free crystal. Wine glasses, with the exception of the hock glass, are generally not coloured or frosted as doing so would diminish appreciation of the wine's colour.

The effect of glass shape on the taste of wine has not been demonstrated by any scientific study and remains controversial. It is however believed by some that the shape of the glass is important, as it concentrates the flavour and aroma (or bouquet) to emphasize the varietal's characteristic. One common belief is that the shape of the glass directs the wine itself into the best area of the mouth from the varietal. This is based on false ideas about the nature of taste buds on the tongue, such as the thoroughly discredited tongue map.
Generally, the opening of the glass is not wider than the widest part of the bowl.
Most wine glasses have stems, although stem less wine glasses are now available in a variety of sizes and shapes as well these glasses are typically used more casually than their traditional counterparts, as they negate the benefits of using stemmed wine glasses.
Most common wine glasses can be divided into three types: red wine glasses, white wine glasses and champagne flutes. Wine tumblers (without stems) are also increasing in popularity.

Red wine glasses 
Glasses for red wine are characterized by their rounder, wider bowl, which increases the rate of oxidation. As oxygen from the air chemically interacts with the wine, flavour and aroma are believed to be subtly altered. This process of oxidation is generally considered more compatible with red wines, whose complex flavours are said to be smoothed out after being exposed to air. Red wine glasses can have particular styles of their own, such as

Bordeaux glass: tall with a broad bowl, and is designed for full bodied red wines like Cabernet Sauvignon and Syrah as it directs wine to the back of the mouth.

Burgundy glass: broader than the Bordeaux glass, it has a bigger bowl to accumulate aromas of more delicate red wines such as Pinot noir. This style of glass directs wine to the tip of the tongue.

White wine glasses
White wine glasses vary enormously in size and shape, from the delicately tapered Champagne flute, to the wide and shallow glasses used to drink Chardonnay. Different shaped glasses are used to accentuate the unique characteristics of different styles of wine. Wide mouthed glasses function similarly to red wine glasses discussed above, promoting rapid oxidation which alters the flavor of the wine. White wines which are best served slightly oxidized are generally full flavored wines, such as oaked chardonnay. For lighter, fresher styles of white wine, oxidation is less desirable as it is seen to mask the delicate nuances of the wine. To preserve a crisp, clean flavor, many white wine glasses will have a smaller mouth, which reduces surface area and in turn, the rate of oxidization. In the case of sparkling wine, such as Champagne or Asti, an even smaller mouth is used to keep the wine sparkling longer in the glass.

Champagne flutes
Champagne flutes are characterised by a long stem with a tall, narrow bowl on top. The shape is designed to keep sparkling wine desirable during its consumption. Just as with wine glasses, the flute is designed to be held by the stem to help prevent the heat from the hand from warming the liquid inside. The bowl itself is designed in a manner to help retain the signature carbonation in the beverage. This is achieved by reducing the surface area at the opening of the bowl. Additionally the flute design adds to the aesthetic appeal of champagne, allowing the bubbles to travel further due to the narrow design, giving a more pleasant visual appeal.

Sherry glass
A sherry glass is drink ware generally used for serving aromatic alcoholic beverages, such as sherry, port, aperitifs, and liqueurs, and layered shooters. The copita, with its aroma-enhancing narrow taper, is a type of sherry glass.

A Boccalino is a mug used in Ticino, Switzerland, to drink local wine (Merlot or similar). It has a volume of approximately 200 ml.

In the 18th Century, glass makers would draw spiral patterns in the stem as they made the glass. If they used air bubbles it was called an air twist; if they used threads, either white or coloured, it would be called opaque twist.

The Difference between Crystal and Glass Stemware
Crystal is glass with lead monoxide in it and, depending on what country you live in, percentages of lead monoxide can vary from 1% (in the US) to 30% (in Europe). Many glassware manufacturers also make lead-free crystal glassware with zinc and magnesium oxide, which also refracts light. Using leaded or lead-free crystal for wine glasses is popular for two reasons: First, the minerals cause the glass to have light refraction which gives stemware a sparkle. Secondly, the inclusion of minerals in glass makes it sturdy enough to be spun very thin.

Regular glass doesn’t shine the same way as crystal but it is more affordable and also tends to be more durable.

Thursday, February 23, 2017

The Fasting Rules on Maha Shivratri

Maha Shivaratri is a Hindu festival celebrated annually in honour of the God Shiva. There is a Shivaratri in every luni-solar month of the Hindu calendar, on the month's 13th night /14th day, but once a year in late winter (February/March, or Phalguna) and before the arrival of spring, marks Maha Shivaratri which means "the Great Night of Shiva".

It is a major festival in Hinduism, but one that is solemn and marks a remembrance of "overcoming darkness and ignorance" in life and the world. It is observed by remembering Shiva and chanting prayers, fasting, doing Yoga and meditating on ethics and virtues such as self-restraint, honesty, non-injury to others, forgiveness and the discovery of Shiva.The ardent devotees keep awake all night. Others visit one of the Shiva temples or go on pilgrimage to Jyotirlingams. This is an ancient Hindu festival whose origin date is unknown.

Wednesday, February 15, 2017

Arrest and custody

An arrest is the act of depriving a person of their liberty usually in relation to the purported investigation or prevention of crime and presenting the arrestee to a procedure as part of the criminal justice system.

Custody is the care, possession, and control of a thing or person. It is the retention, inspection, guarding, maintenance, or security of a thing within the immediate care and control of the person to whom it is committed. Thus custody is detention of a person by lawful authority or process.

Arrest is a short term event to be followed by Custody if approved of by a legal judicial authority.

Police Custody and Judicial Custody

Police custody literally means protection and care provided by the police while a person under judicial custody is under the protection and safety of a judge.

Police custody starts when a police officer arrests a suspect and reads him his rights while judicial custody happens when the judge orders that the suspect be put under this type of custody.

A suspect under police custody can be interrogated about the specific crime while this action is void under judicial custody. It can only be revoked when the judge orders it to be broken.

Police custody is the initial custody of a suspect. After a judge evaluates the case, the suspect can either have temporary freedom (by posting bail), judicial custody, or be taken again into police custody.

Tuesday, December 6, 2016

PM Modi Pays Tribute to Jayalalithaa

Prime Minister Narendra Modi hugged new Tamil Nadu Chief Minister O Panneerselvam as the latter wept inconsolably when the Prime Minister visited Chennai's Rajaji Hall, a large public auditorium where J Jayalalithaa's body was placed for people to pay their respects before she was burried at Chennai's Marina beach near her political mentor MGR. PM Modi was also seen patting Ms Jayalalithaa's long-time companion Sasikala Natarajan on the head. Ms Natarajan too broke down and PM Modi consoled her, stopping for a few minutes to talk to her.

Thursday, October 13, 2016

How to insert sim card, battery, SD card, into a smart phone

This video is tutorial for novices on how to insert sim card, SD card, battery in Intex Cloud Fx firefox smartphone. This video is meant only for the novices, who are the first time buyer of any smartphone.