Black bodies in addition to emitting the highest energy at all wavelengths also completely absorb radiation of all wavelengths falling on them. Radiation emitted by a black body is a function of its temperature only. However, there are no perfect black bodies. A body that is closet to a perfect blackbody is cavity having a small hole on the surface. The wall of the cavity is maintained at a constant temperature. All the radiation falling on to the hole gets in to the enclosure and has little or no chance of coming out. That is the radiation falling on the hole is completely absorbed. The radiation that comes out is the radiation that is present in the enclosure. If the enclose is at a temperature T, then the radiation that comes out of the hole has the characteristics of blackbody radiation at temperature T.
In the normal duodenum or the stomach there is a natural barrier to protect the mucosa from autodigestion. This barrier includes mucous secreted by the goblet cells, HCO1- ions and rapid division of the gastric and duodenal epithelial cells. Under normal conditions there is equilibrium between attack and defense in the stomach and the duodenum. But under pathological conditions this equilibrium is lost.
Pepsin-(secreted by the peptic cells) and HCl - (secreted by the parietal cells) are responsible for the erosion of the gastric mucosa. Mucous layer lining the inner surface of the stomach and duodenum slows the diffusion of HCl and pepsin to the epithelial lining. Also HCO1- neutralizes the any diffusing H+ ions.
But the usage of non steroid anti inflammatory drugs reduces the secretion of mucous and fosters the formation of peptic ulcers. Also a bacteria known as Helicobacter pylori colonize on the mucous membranes and causes damage to mucous lining.
Few decades ago the treatment for the peptic ulcers was only by surgical intervention. But with the development of the new drugs treatments for the peptic ulcers include neutralization of the stomach acid by antacids, relieving the pain by pain killers, usage of proton pump inhibitor drugs, Anticholinergic agents and Histamin H2 receptor antagonists. For the perforating peptic ulcers surgical intervention is necessary.
Antacids- Magnesium hydroxide
Proton pump inhibitors- Omeprazol
Landscape Architecture is the art and science of modifying land areas by organizing natural, cultivated or constructed elements according to comprehensive aesthetic plan. These elements include topographical features such as hills, valleys, rivers and ponds, vegetation such as trees shrubbery, grass and flowers and constructions such as buildings, terraces, roads, bridges, fountains and statuary. No unalterable rules exist in landscape architecture because each plot of ground offers unique problems caused by variation in contour, climate and surrounding areas.
Landscape architecture was formerly called landscape gardening and was limited to the creation of gardens around private dwellings. Today landscape architecture covers a much wider area of concerns, ranging from setting out of small gardens to the ordering of parks, malls and highways. It includes landscape gardening, which is now understood as the work done by commercial gardeners, who install and care for flowers and greenery according to the design of landscape architects. The landscape architect who usually holds an academic degree in this field has the same professional standing as an architect or engineer and receives a fee directly from the client. The landscape gardener may be a commercial contractor or an amateur, who landscapes the grounds of a private home. In
Landscape Architecture seeks to apply design in its fullest sense in order to ensure the best possible adaptation of the means to an intended carefully considered end of the new scene. Therefore the artistry or visual appreciation must act in unison with the sciences of the earth. (Colvin 1997)
In the Sri Lankan traditions the concept of created landscape can be identified in three forms. By adapting, improving and maintaining natural forest as a habitable forest garden called `Vana', 'Arama' or'Uyana'.
Creating parks by planting flowering trees and fruit trees for relaxation, beauty and shade. By creating landscape gardens in architectural precincts.
In creating three landscapes different types of trees selected from nature plays a major role. (De Silva 1990)