May 172013

Wright Brothers, Wilbur and Orville Wright were born in 16 April 1867 and 19 August 1871 in Millville Indiana and Dayton Ohio respectively. His father was an editor of a newspaper published by Church of the United Brethren in Christ. Their family moved to different places due to the jobs as a minister of the church.

Famous as: The Wright Brothers
Born on: 16 April 1867 and 19 August 1871
Born in: Millville Indiana and Dayton Ohio
Nationality: American
Major works and Achievement: Invention of aeroplane.

Wilbur and Orville Wright passed their childhood very happily. Their family is very courageous so that they developed intellectual and creativeness. They got the suitable environment which was required for the overall development of the children and the family was also very courageous.

They both were very interested on reading books and finding new things. They kept keen interest on flight when his father brought them a toy helicopter. It was invented by French Aeronautical Pioneer Alphonse Penaud which was made by using cork, bamboo, paper, rubber band, blades. After passing few years, they both tried to make such toy themselves.

In 1884, their family moved to Dayton from Richmond, Indiana before Wilbur finished his graduation from high school and in next year he again attended high school in Dayton for further studies in Greek and trigonometry.

Wilbur was hit with a hockey stick in the face while he was playing ice-skating game and lost his front teeth. It was not so serious accident which was taken in 1885-1886 in the winter. Again Wilbur was struck him when the bat accidentally flew out of the hand of a young man and knocked out. From this accident, he suffered from heart problem. He was taken care for four years at his house and sent to Yale College. Due to suffering from heart problem, he was so depressed. He also started reading extensively from the family library.

In 1889, Orville had designed and made a printing press with the help of Wilbur and started publishing weekly and daily newspapers. Further they opened a bicycle shop and manufactured their own brand of cycle. Orville also invented a self-oiling wheel hub. That year German aviator Otto Lilienthal died in a glider crash, but his pioneering work showed that manned flight was feasible. After that, French aviation researcher Octave Chanute collected data and brought young aviators to experiment with gliders on the sand dunes at Lake Michigan shore. The interest of Wright brothers in flight was renewed and they set about to learn everything they could about the subject by gathering and reading whatever they could and later designing experiments of their own.

The Wright brothers needed to find a place with more wind to provide adequate lift for large gliders. In November 1899, Wilbur Wright wrote to Willis L. Moore, Chief or the US Weather Bureau, asking about high wind conditions throughout the US. The first rural place on the list Moore sent back was Kitty Hawk, North California. During the years 1900, 1901 and 1902, the Wright brothers experimented at Kitty Hawk with the help of kites, gliders and a wind tunnel they built to test wing design. They developed the first effective aeroplane and made the historic first aeroplane flight in the year 1903.

The Wright Brothers built an aeroplane that could fly for more than half an hour at a time in the year 1905. In 1908, Orville made the world’s first flight of over one hour at Fort Myer at Virginia in a demonstration for the US Army which subsequently made the Wright Brothers’ planes the world’s first military aeroplanes. That same year Wilbur made over 100 flights near Le Mans, France, the longest one, on December 31, a record flight: 2 hours, 19 minutes.

The Wright Brothers never got married. Wilbur Wright died at the age of 45 years due to Typhoid and Orville Wright died of a heart attack at the age of 77 years.

 Posted by at 8:58 pm
May 142013

Methods of solid waste management

For the proper management of solid wastes different methods have been adopted. Some of those measures are very simple and easy where as some are very complex. Some of those measures are discussed below:

 1. Preparation of compost

Organic matter constitutes 85%-90% of the municipal solid waste generated in Nepal. This waste can be recycled by the method of composting, one of the oldest forms of disposal. It is the natural process of decomposition of organic waste that yields manure or compost, which is very rich in nutrients. Composting is a biological process in which micro-organisms, mainly fungi and bacteria, convert degradable organic waste into humus like substance. This finished product, which looks like soil, is high in carbon and nitrogen and is an excellent medium for growing plants. The process of composting ensures the waste that is produced in the kitchens is not carelessly thrown and left to rot. It recycles the nutrients and returns them to the soil as nutrients. Apart from being clean, cheap and safe, composting can significantly reduce the amount of disposable garbage. The organic fertilizer can be used instead of chemical fertilizers and is better specially when used for vegetables. It increases the soil’s ability to hold water and makes the soil easier to cultivate. It helps the soil retain more of the plant nutrients.

For the purpose of compost preparation, first step is the separation of biodegradable and non-biodegradable wastes. After separation, biodegradable wastes are kept in a pit. The size of the pit and process of preparation depends upon the amount of waste and need of people. The compost preparation is supposed to be suitable method in the context of our country.
  1.  Aerobic Method: Aerobic composting takes place in the presence of ample oxygen. In this process, aerobic micro-organisms break down organic matter and produce carbon dioxide (CO2), ammonia, water, heat and humus, the relatively stable organic end product. Although aerobic composting may p produce intermediate compounds such as organic acids, aerobic micro-organisms decompose them further. The resultant compost, with its relatively unstable form of organic matter, has little risk of phytotoxicity.
  2. Anaerobic Method: In anaerobic composting, decomposition occurs where oxygen is absent or in limited supply. Under this method, anaerobic micro-organisms dominate and develop intermediate compounds including methane, organic acids, hydrogen sulphide and other substances. In the absence of oxygen, these compounds accumulate and are not metabolized further. Many of these compounds have strong odours and some present phytotoxicity. As anaerobic composting is a low-temperature process, it leaves weed, seeds and pathogens intact. Moreover, the process usually takes longer than aerobic composting. These drawbacks often offset the merits of this process, viz. little work involved and fewer nutrients lost during the process.
  3. Vermi-composting: Vermi-composting is the process of using worms and micro-organisms to turn kitchen waste into black, earthy-smelling, nutrient-rich humus. While composting refers to the biological degeneration of organic wastes like yard and food waste by micro-organisms, in vermi-composting, earthworms are used to break down organic wastes into nutrient-rich manure.

2. Sanitary Land fill

Sanitary landfills are sites where waste is isolated from the environment until it is safe. It is considered when it has completely degraded biologically, chemically and physically. A sanitary landfill is a waste disposal facility where layers of compacted garbage are covered with layers of earth. When the facility reaches capacity, a cap is applied to close the site. Sanitary landfills are one of the most popular methods for disposing waste although they have some distinct drawbacks. This technique for waste management was developed in the 1930s, in response to growing pressures created by growing population. Kathmandu valley has been searching for better landfill sites as Sisdol and Okharpauwa are inadequate and there has been political and local pressure. Pokhara valley has also a good sanitary landfill site.

 3. Burning

It is the burning of solid waste without the benefit of a device to adequately control combustion, such as those found in solid waste incinerators. We can burn household waste, trees, logs, bushes, papers, twigs, leaves and stumps so as to reduce the volume of the waste as well as we can obtain ashes which can be used as fertilizers.

 4. Incineration

Incineration is a waste treatment process that involves the combustion of organic substances contained in waste materials. Incineration and other high temperature waste treatment systems are described as “thermal treatment”. Incineration of waste materials converts the waste into ash, flue gas and heat. The ash is mostly formed by the inorganic constituents of the waste and may take the form of solid lumps or particulates carried by the flue gas. The flue gases must be cleaned of gaseous and particulate pollutants before they are dispersed into the atmosphere. In some cases, the heat generated by incineration can be used to generate electric power.

 5. Waste to Energy

Waste is the resource at wrong place at wrong time. We can use waste to generate energy and economy. In Europe, the solid waste is used in central heating system and thy also generate hot water to the people. This again can be used to generate electricity. So, Waste-to-Energy (WtW) or Energy-to-Waste (EtW) is the process of creating energy in the form of electricity or heat from the incineration of waste source. It is a form of energy recovery. Most WtE processes produce electricity directly through combustion, or produce a combustible fuel commodity, such as methane, methanol, ethanol or synthetic fuels.