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.

Objectives: The study aims to: (1) assess the prevalence of phantom vibration and ringing syndrome among
nurses, (2) determine the level of job-related stress among those nurses who are working at teaching hospitals in
Al- Nasiriyah city, and (3) identify the association between job-related stress and experience of phantom
vibration and ringing syndrome.
Methodology: : A descriptive design, cross-sectional study was used for the present study was carried out
from 4th December, 2017 to the 4th April, 2018 in order to determine the association of Phantom
Vibration and Ringing Syndrome with Job - Related Stress among nurses at Teaching Hospitals in AlNasiriyah
City , on a purposive (non-probability) sample was used in t

Inherent fluctuations in the availability of energy from renewables, particularly solar, remain a substantial impediment to their widespread deployment worldwide. Employing phase-change materials (PCMs) as media, saving energy for later consumption, offers a promising solution for overcoming the problem. However, the heat conductivities of most PCMs are limited, which severely limits the energy storage potential of these materials. This study suggests employing circular fins with staggered distribution to achieve improved thermal response rates of PCM in a vertical triple-tube heat exchanger involving two opposite flow streams of the heat-transfer fluid (HTF). Since heat diffusion is not the same at various portions of the PCM unit,

Research on geopolitical and geopolitical studies relates to a range of sciences that can be called auxiliary sciences, such as political science, international relations in particular, and history, but their focus is rarely on science and ethnography

That the issues and problems of the world today has become so large and complex that does not allow a specific field or knowledge to solve one of the need for the newly known knowledge integration (geopolitics and geopolitics) in particular to move towards cognitive integration to understand many of the problems and global issues that faced The importance of this study comes to clarify the relationship between Darwinism, geopolitics and geopolitics. The geopolitics in modern terms d

Abstract:
Humanitarian intervention has taken different forms included within the
peaceful and military means to stop the human suffering, whether caused by
natural disaster or humanitarian disasters.
Intervention can not be acquitted because it carries with it political cover,
but sometimes it may be legitimate cover for the occupation and the violation
of sovereignty. Therefore, the research worked to capture the legal and
political aspects of international law and the role of international organizations
to intervene and the right to use force.
The research concludes that international law had not been fairly
successful in controlling the behavior of some countries in the use of force,
and that there is