The spectral response of the Si solar cell does not coincidence with the sun irradiance spectrum, so the efficiency of the Si solar cell is not high. To improve the Si solar cell one try to make use of most region of the sun spectrum by using dyes which absorb un useful wavelengths and radiate at useful region of spectrum (by stock shift). Fluorescence's dye is used as luminescent concentrator to increase the efficiency of the solar cell. The results show that the performance efficiency and out power for crystalline silicon solar cells are improved.

New designs of solar using ray tracing program, have been presented for improved the performance and the out put power of the silicon solar cell, as well as reducing the cost of system working by solar energy. Two dimensional solar concentrator (Fresnel lenses) and three dimensional concentrators (parabola dish and cassegrain) were used as concentrator for photovoltaic applications (CPV). The results show that the performance efficiency and out power for crystalline silicon solar cells are improved.

     This research introduced the derivation of mathematical equations to calculate the Cartesian and geographical coordinates of a site situated at a far distance from the observer position by using GPS data. The geographical coordinates (Ï•obs., λ obs., hobs.) for observer position were transformed to Cartesian coordinates (X obs., Y obs., Z obs.) of observer position itself. Then the Cartesian coordinates of unknown position mathematically were calculated from these calculated equations, and its transformed to geographical coordinates of (Ï•unk., λunk.) position.
 

The human resources are considered to be the main pillar of the organizations , economic development and the foundation of moving wheels of individual growth. This is considered as the basic tasks for any productive and economic activity . The investment of the human resources is the economic pillar of production , but the most important element of the production . This research tried to access the method of resource investment and to identify the problems and training as key element in establishment of E –government . A questionnaire document have been distributed to the workers at different levels in the colleges and institutes. The research concluded the necessity of job description , continuous training of the workers , usi

Back ground: This study was conducted to estimate the relation ship of the incisive papilla to the antero posterior arrangement of the maxillary anterior teeth in a two different groups (Iraqi and Yemenian groups), because incisive papilla is considered as a reliable and relatively stable anatomic land mark.
Materials and Methods: Maxillary and mandibular stone casts were collected from 100 dental students, (50) of Iraqi dental students in Baghdad university and (50) of Yemenian dental students in Ibb university at the 3rd and 4th classes. Age ranged from 21-25 years. Alginate impression, dental stone, stock trays were used. Photographic technique was used to measure anatomic land marks located on de

This research aims to study the effect of heat on the efficiency of solar cells of neutrons ranging from card to these cells in the case of dark and light before and after irradiation using the neutron source as well as electrical properties have been studied

In a global context increasingly concerned with climate change, understanding the impact of economic growth on the environment is becoming crucial, especially for developing countries. Morocco has been committed to the United Nations Framework Convention on Climate Change (UNFCCC) to achieve the objectives set for reducing greenhouse gas (GHG) emissions by 13% by 2030, with 2010 as the reference year. Such a target could reach 32% by the same horizon under certain technical, financial and capacity building support conditions.
The main emitters of greenhouse gases (CH4 and CO2) are landfills because during the decomposition of solid waste CO2 is the most present gas pollutant is for this reason focuses this case study carried out in a