The current study presents an experimental investigation of heat transfer and flow characteristic for subcooled flow boiling of deionized water in the microchannel heat sink. The test section consisted of a single microchannel having 300μm wide nominal dimensions and 300μm height (hydraulic diameter of 300μm). The test section formed of oxygen-free copper with 72mm length and 12mm width. Experimental operation conditions spanned the heat flux (78-800) kW/m2, mass flux (1700 and 2100) kg/m2.s at 31˚C subcooled inlet temperature. The boiling heat transfer coefficient is measured and compared with existing correlations. Also, the experimental pressure drop is measured and compared with microscale pressure drop correlations. The results showed that higher mass flux leads to higher boiling heat transfer coefficient, and the dominant mechanism is convective boiling. Also, the experimental pressure drop decrease with increasing heat flux in a single-phase region while it increases in a two-phase region. Comparing the experimental results in the experimental condition range, showed that an existing correlation provides a satisfactory prediction of heat transfer coefficient and pressure drop.
The current study aimed to identify the morphological description and branches of the bronchial tree and lung for the weasel
The anatomical features of Agave americana L. leaf have been described, transverse sections of the leaf have been examined, the epidermis is single-layered on both surfaces, the stomata are sunken and mesophyll is (2-3) layers of parenchyma cells, vascular bundles are collateral type. The pollen of A. americana was studied. The observation was made with L.M. (Light microscope) and S.E.M. (Scanning electron microscope) to determine the significance of pollen features as taxonomic characters. The pollen was monades, homopolar, monosulcate, and with large size, subprolate in shape from P/E ratio (Polar axis/ Equatorial diameter) and furrow length and width, exine thickness and ornamentation.
Enrollment in kindergarten child accomplishes many positive aspects, that’s what Im sure a lot of modern educational trends in child education preschool in the importance of exposing children to a variety of sensory stimuli that contribute to impart a range of sound concepts.
Current research aims to know:
1.the level of sensory perception in the first primary grade students a sample search.
2.differences in perception of elementary first-graders with variable gender male, female)) 3.differences in perception of the first primary grade students attending and not attending kindergarten in accordance with variable attendance (attending, not attending).
school students (first grade) from attendi
... Show MoreThe research problem boils question is there in Riyadh organizational climate that enables them to do their work properly and whether there are differences between the government and private Riyadh depending on the organizational climate has sought Find measure: 1 regulatory climate for kindergarten 2. The difference between government and private Riyadh depending on the organizational climate. Limited research on the (200) parameter of the Riyadh government and private parameters for the year (20,142,015) In order to achieve the research objectives the researchers built a regulatory climate in accordance with the scientific steps to build a psychological scales measure After the formulation of climate regulation paragraphs of the (30) p
... Show MoreThe present study was designed to investigate the normal histological features of the stomach at the prenatal stage from ten healthy pregnant rabbits at the third period of pregnancy. The stomach appeared as J-shaped situated at the left part of the abdominal cavity. It found in the front part entirely within the rib. The non-glandular region act as a reservoir, the septa prevented ingesta reflux into the esophagus. Histologically the stomach in both periods composed of four tunics', which were mucosa, tunica submucosa, tunica muscularis and tunica serosa. The stomach also has different regions cardiac, fundic and pyloric regions, glands in the cardiac region were coiled branched tubular gland and almost present of the mucous cells
... Show MoreIt can be said that the Security of water in Basra from the visual task vital strategic issues of concern to the attention of researchers in various attributions and those interested in water, environmental, economic, social, cultural and political affairs ... etc. This view of the great importance of the issue of water in the occupied Basra, which is characterized by parochialism and scarcity, When looking at the sources of our daily lives and in our reality today. We find that millions of people living on the two main exporters Tabaaan oil and water. And depleted oil wealth However Manfred him the most attention because we entered it surpasses all other sources of income, but is not it a littl
... Show MoreThe Logic of Freezers and Animals in the Holy Quran
Oxidative stress is oxidative damage caused by free radicals and reactive oxygen species (ROS). These ROS can cause oxidative damage to cellular components, including membrane lipids, receptors, enzymes, proteins, and nucleic acids. It would eventually lead to cell apoptosis and the appearance of certain pathological conditions. This work investigates the antioxidant potentials of chamomile extract in vitro by evaluating the extract activity to scavenge 2,2-Diphenyl-1-picrylhydrazyl (DPPH), also in vivo by investigating its effects on oxidative stress-induced rats by assessing the total oxidant status (TOS) and total antioxidant capacity in the radiation exposed rats with and without the treatment with chamomile extract. The results
... Show MoreCountries are developing the spatial development of their societies through the projects that they undertake in various ways, and this development may be cause great impact on the environment, which also depend on the type of development, whether industrial, agricultural, or service and after the problems that occurred as a result of development on the environment, most of the countries currently did to legislating laws Environmental and some other procedures before granting environmental approvals for the purpose of establishing spatial development projects. One of the most important of these laws and regulations is Environmental impact assessment (EIA). The environmental impact asse