Refrigeration And Air Conditioning By Arora And Domkundwar Pdf' title='Refrigeration And Air Conditioning By Arora And Domkundwar Pdf' />Abstract Current World Environment. INTRODUCTIONIncreasing population and higher levels of human activities including effluent disposals to the surface and groundwater resources have made sustainability of resources a very complex task throughout the world. Water is known to contain a large numbers of chemical elements. Physical parameters such as temperature, turbidity and current are also known to operate in Lake Ecosystem. The interaction of both the physical and chemical properties of water plays a significant role in the composition, distribution and abundance of aquatic ecosystem. Apart form this, it also gives an insight into the relationships between the organism and their environment and can be used in determining water quality, and productivity of the lake. The physico chemical study could also help in understanding of the structure and function of a particular water body in relation its habitants. INTRODUCTION. One of the major concerns of many countries today is that there is a mismatch between graduates skills, acquired from higher education institutions. Air conditioning 2c. The proper balance of physical, chemical and biological properties of water in lake is an essential ingredient for successful production of aquatic resources. Water is one of the important sources, to sustain life and has long been suspected of being the source of much human illness. Source of surface water and ground water have become increasingly contaminated due to increased industrial and agricultural activity. The public desires water that is low in hardness and total solids, non corrosive and non scale forming. A fascinating thing about lakes is that they provide their own variety. The task of limnologist is to measure and interpret this variation whether it concerns physical, chemical, biological phenomena, altitude, geology of the catchments area and the depth of water. Increased use of lakes and reservoirs for recreation, fisheries, water storage for irrigation and electric power generation purposes as well as for urban shoreline development, has emphasized the need for intensive water quality studies and management. The physical and chemical limnology of a lake is characterized by hydrologic impact, autogenic nutrient dynamic and biological aspects. These factors combine with each other determine the water quality and consequently community of the lake. Iraqi Kurdistan is considered a rich area with water resources if compared to its size, the water resource is available in different forms, including surface water river, stream, spring, Kareeze and lake, groundwater, rain and snow, the second important lake is Derbendikhan reservoir which was constructed on Serwan river, this reservoir was established for flood control, irrigation, power generation, fish wealth, in addition to improving environmental and developing tourism, through the last 1. Derbendikhan lake, the reason is back to the low precipitation rate, which lead to increasing the levels of pollutants, thus the object of this study is to determine the physico chemical properties and algal composition and assessment the water quality of the lake. Description of the area. Derbendikhan Lake Fig. Sulaimani, boundaries extended from latitude 3. N and longitudinal 4. E, and the second largest lake in the Iraqi Kurdistan region at an altitude of about 4. The area of this water lake is about 1. K2 with the maximum depth of 7. The estimated volume of the Derbendikhan lake ranges from 1. Km. 3 6. Consequently Derbendikhan can be classified as limnetic water body, as warm and monomictic with only one circulation period in winter and water temperature never falls below 4C8. Geology of the area consists of sedimentary rocks of marine origin. The collection decision of 9 regarding the climate of the studied area is a dry summer approaches Irano Turanian type characterized by the occurrences of three seasons a cold winter, mild growing period of spring and hot dry summer. Two sites in Derbendikhan mid lake and lake outlet were carried out seasonally variation over period of 4 seasons 1. Fig. 1. MATERIAL AND METHODSSeasonally surface water samples were taken from two selected site in Derbendikhan lakeone in mid lake and the second in the lake outlet main channel seasonally over period of 4 seasons 1. Air and water temperature was measured immediately in the field by placing a clean mercury thermometer 0 6. C graduated up to 0. C inside the water. EC, TDS p. H were measured by using p. H EC TDS meter, HI 9. Hanna instrument. Alkalinity, total hardness, dissolved oxygen, Ca2 ,Mg2 ,Na1, K1,sulfate and chloride were estimated. Nitrite, phosphate and silicate were estimated. Identification of algae was carried out using compound microscope model, Olympus in accordance to the available reference identification text books. RESULTS AND DISCUSSIONLakes are an important natural resource for population lived around the vicinity. They provide water for domestic and industrial uses, fisheries and irrigation. Knowledge of Lake Hydrology is essential for their proper use and conservation. The physicochemical parameters and nutrient content of water play a significant role in the distributional patterns and species composition of primary organisms Sahato et al. In aquatic habitats, environmental factors include various physical properties of water, such as solubility of gases and solids, light penetration, temperature and density. Chemical factors such as p. H, hardness, phosphate and nitrate are very important for growth and dispersal of the phytoplankton depend for their existence. The results Tables 1, 2, 3 4 showed that the parameters studied were effective in identifying and monitoring water bodies affected by organic sewage discharges. Hydrographic condition of Derbendikhan Lake, seasonal and physico chemical change in water surface affect the abundance and distribution of biodiversity. Tables 5, 6, 7 8 show the significant differences between the two sites for different physico chemical characteristics, that sows found significant differences between the sites in some characteristics and not found in others characteristics, and these clear phenomena in these tables. Temperature is important in terms of its effect on aquatic life. Temperature fluctuations are evident seasonal patterns in aquatic ecosystems. Orange Paris Wifi Hotspots. Its influence on limnological phenomena such as stratification, gas solubility, p. H, conductivity and planktonic distribution are well known Singh et al. Temperature measurements are useful in indicating trends for various chemical, biochemical and biological activities. An increase in temperature leads to faster chemical and biochemical reactions. The growth and death of microorganisms and the kinetics of the biochemical oxygen demand are also regulated to some extent by water temperature Khuhawar and Mastoi. The air temperature showed an annual variation about 1. C at the sampling sites in Derbendikhan Lake. A higher air temperature was observed in August, particularly at site one during 2. February, particularly in site one during 2. In this study fluctuation of air temperature depend on the climate of the areas which closely approaches the Irano Turanian type. The climate of the area characterized by semi arid type with a wide seasonal range in air temperature. Statments by 9 and 1. Water temperature in the study lake was closely followed by air temperature, with maximum in summer and minimum in winter. Air and water temperatures showed a very characteristic annual cycle, with higher values during the winter was 3. C and lower values in the summer was 1. C. This variation may be related to many environmental factors such as elevation, current velocity, water depth bottom materials expose to direct sun light and degree of shading or vegetation cover, evaporation and wind speed 1. Similar conclusion made by 2. The results indicated that the water of Derbendikhan lake was rich and high dissolved solids. Surface water samples of Derbendikhan lake appeared an electrical conductivity of 4. The highest value recorded in October 2.