Monday, April 22, 2013

Wonders of the world: Spiders

Tree spider


When I was a child like my other friends, I was scared of spiders. Even now when I see a spider in my room, certainly I do not scream, but yet, I avoid them and try to chase them out from my room. When I grew up little by little, I wanted to get rid of this fear and crazy imaginations about spiders, so I started reading about spiders in order to get familiarize with these little fascinating creatures.
We all know that spiders are disliked by many people due to their lack of knowledge about spiders. According to the taxonomy of spiders, they belong to the class Arachnida Phylum Arthropoda. These spiders are carnivores which mean they feed on small insects or flesh. They do it by trapping their pray using their web or by hunting on ground. In addition, these spiders can be seen all over the world except in air since they do not have wings to fly and in ocean since they are air-breathing animals. Yes, there are some spiders who can live under water such as Diving Bell Spider ( Argyroneta Aquatica) but they also need air. In this case they trap air in a bubble held by hairs on its abdomen and legs.
Another reason is their size and the appearance which give an expression that they should not be petted or loved, they are venomous and dangerous. When we consider about their size, most spiders are relatively small (2-10 mm) but there are exceptions like Tarantula whose body length will extend up to 80-90 mm. Even though size varies from one spider species to another, their body consists of two main parts. First part is the “Cephalothoraxe” (Prosoma) which is the anterior part and the other part which is the posterior part, known as “Abdomen” (Opisthosoma)

Monday, August 20, 2012

CONSTRUCTED WETLANDS AS A METHOD OF WASTEWATER TREATMENT


          Since most chemical reactions take place in water based medium, water plays a major role in industrial world. With the polar nature of water it easily gets polluted from those chemical and biological ingredients use in manufacturing process. This polluted water is called industrial effluents or simply the wastewater. Since industrial wastewater contain toxic chemical compounds like Cyanides, biological waste like plant materials and pathogens, toxic heavy metals like Cadmium, Lead, exceeding the accepted levels for human use. When this wastewater released in to natural water bodies it may result social and health problems to the people living around the water resource and also to the people who use it for day today work. 
Minamata Disease (methylmercury poisoning) on Public Health & Social Justice 
socialmedicine.org
In early days people tends to release this waste water to natural water bodies without a proper treatment. Therefore in early days outbreaks due to hazards waste were common. Minamata outbreak in Japan is such a disaster coursed by not having a proper treatment for wastewater. Wastewater treatment is an expensive process, if we are using conventional methods like chemical precipitation, Ion exchange; Reverse Osmosis and Electro dialysis. Not only they are expensive but also they produce toxic sludge therefore small industries won’t consider about having a wastewater treatment plant within their manufacturing plants due to the high production cost. Instead they release wastewater to the nearby water stream without treating it.

Monday, July 9, 2012

German Shepherd Dog (GSD)



Since Interesting fact about cats’ post I haven’t wrote about animals. So I thought to write about dog which I love to have around me all the time. From cunning fox to dreadful wolf, and to African wild dogs which are hunts in packs, are belong to family Canidae or simply dog family.
German Shepherd Dog is one of my favorite dog breed. And I think every dog lover know the answer why I’ am so much interested about them. German Shepherd Dog is a large size dog breed originated from Germany. Height: 60-65cm. Weight: 35-40kg (Dog breed info center). Since these dogs are strong, intelligent and loyal, initially they used to herding and guarding sheeps. After people get familiar with this breed people use this breed for police and military roles around the world (Wikipedia)

Wednesday, June 20, 2012

MOON PLAINS SANITARY LANDFILL


In Sri Lanka, disposal of waste is a major environmental and social problem, which leads to several health problems like dengue in urban areas. As responsible government, Sri Lanka should have a proper way of disposing of waste. But in Sri Lanka, disposal of waste is mainly done by maintaining an open dump site, which will cause many environmental and health problems. Instead of open dumpsites, one proper way of deposing waste is maintaining a sanitary landfill. Moon Plains is one such sanitary landfill, which is started in 1996 by the Nuwara Eliya municipal council as a normal dumping site, and converted in to a sanitary landfill in 2003 with the help of JICA foundation. This land fill is located in a valley surrounded by a cultivated Eucalyptus forest, which is owned by the forest department, outside the Nuwara Eliya municipal council. And it is close to a water stream which provides water to a reservoir called Bomuraella which used for domestic and agricultural purposes by the people who are live around the reservoir. Initially this valley is used as an open dump site by the Municipal council without taking any environmental protection measures.
This valley which is 400m long and 30-40 meter deep is a part of 5.8ha catchment. And this valley consists of sandy clay soil and bed rock is a hard rock. Since Nuwara Eliya located in wet zone annual rain fall is around 2700mm therefore it gives rice to a seasonal stream which connects to the close by stream. When all the Municipal waste, Hospital waste and industrial waste is dump without any environmental protection measures it can easily contaminate that water stream and the reservoir causing serious environmental and health care problems to the society.

Wednesday, November 2, 2011

COAL FIRED ELECTRICITY GENERATION.

              Energy, we all need it to do a work. As humans we use energy stored in our body. But most of the time energy stored in our body is not sufficient enough to finish the required work. Therefore we use machines to do our work. Most of these machines driven by electricity which makes electricity to play a major role in the form of energy for development of a country. Electricity generation required an efficient energy source. Energy sources that we use today is limited resulting a global problem called energy crisis.s
              Hydro power is the most common energy source that people familiar with the electricity generation in Sri Lanka. Other than that developed countries use nuclear energy to generate electricity. Fossil fuels, geothermal energy is also using for electricity generation. Due to the modern climatic changes hydro power stations cannot operate at their maximum capacity. And Nuclear power plants need more advanced technology and more capital which cannot afford by developing country like Sri Lanka, which lead to find a convenient alternative energy source to generate electricity. Such convenient alternative energy source is Coal. Coal is a solid fossil fuel which containing Carbon and it is the most impure of fuels, its impurities range from trace quantities of many metals including uranium and thorium to much larger quantities of aluminum and Iron to still larger quantities of impurities of such as Sulfur.