Transient three-dimensional natural convection heat transfer due to the influences of heating from one side of an enclosure filled with a saturated porous media, whereas the opposite side is maintained at a constant cold temperature, and the other four sides are adiabatic, were investigated in the present work experimentally. Silica sand was used as a porous media saturated with distilled water filled in a cubic enclosure heated from the side,using six electrical controlled heaters, at constant temperatures of (60, 70, 80, 90, and 100oC). The inverse side cooled at a constant temperature of (24oC) using an aluminum heat exchanger, consisted of 15 channels feeded with constant temperature water. Eighty thermocouples were used to control the heated and cooled sides, and to measure the temperature in the entire enclosure. Experimental results showed that the heat transfer regime was mainly conduction for all Rayleigh numbers with small influence of convection for Ra=42 and greater for Ra=55. This effect increased with the angle of inclination of the enclosure. Numerical and experimental results showed a good agreement. There was a rapid increase in the temperature at the entire media at the early time, reduced gradually until the steady state condition reached. This temperature and heat transfer to and from the porous media, were increased as the Rayleigh number and/or inclination angle increased. The Nusselt number increased directly with the angle of inclination up to o θ = 45 and then decreased. Correlation equations are obtained from the experimental investigation, showed the change of the average and local Nusselt number with time, distance, Rayleigh number, and the inclination angle.
Background: Green Tea is made from the leaf of the plant “Camellia sinensisâ€. Green tea is reported to contain thousands of bioactive ingredients including catechins which have shown great promise for having antimicrobial effects. Periodontal diseases represent one of the most prevalent diseases around the world and the main etiologic factor behind it, is plaque accumulation, in addition certain kinds of bacteria have been detected frequently in subjects suffering from periodontitis, Several studies suggested that the outcome of periodontal treatment is better if particular pathogens including Aggregatibacteractinomycetemcomitans can no longer be detected after therapy. Materials and Methods: plaque samples were collected from 2
... Show MoreThe current study aimed to identify the morphological description and branches of the bronchial tree and lung for the weasel
Background: Hypothyroidism is a clinical syndrome prevalent in women, even those of reproductive age. Ovarian reserve can be defined as the number and quality of follicles in the ovary at any given time. Evaluation of ovarian reserve is recommended for patients at risk of decreased ovarian reserve. Objective: This study aims to evaluate the effect of hypothyroidism on ovarian reserve in Iraqi women by hormonal measurements of serum anti-mullerian hormones AMH, FSH, and LH. Subjects and methods: This case–control study was carried out at the Department of Biochemistry, College of Medicine, University of Baghdad, in collaboration with Endocrinology and Diabetes Clinic, Baghdad Teaching Hospital, and National Center for Teaching Labo
... Show MoreBackground: Tooth eruption is a more general process, however, which includes certain posteruptive tooth movements. There are two fundamental requirements for both tooth eruption to occur: (1) Require soft tissue, intervening between tooth structure and alveolar bone, which plays an important role in regulating the remodeling of adjacent tissues. (2) Require bone turnover that is temporally and spatially regulated to facilitate specific translocations of teeth through alveolar bone These amniotic stem cells are multipotent and able to differentiate into various tissues, which may be useful for human application and recently it used in many medical branches. CD34 is an endothelial marker that is extensively used in immunohistochemistry a
... Show MoreDell Hymesin 1964coined The Ethnography of Communication in an attempt to explain the ways in which people use the language to interact. It hypothesizes that ethnography is less applicable among participants who have the same sociocultural background. It was proven that all the basic speech components occur whenever there is an interactional situation. The elements of (SPEAKING) schema are closely connected. However, the findings establish the fact that these elements take place effectively among participants who have the same sociocultural background.One of the most outstanding conclusions is the capability of the (SPEAKING) model to analyze not only an interaction between two or more participants, but also any event which consists of a mo
... Show MoreAs a kind of linguistic study, the study of presupposition in drama is one of captivating topic to explore, because of the capability of this topic to make people perceive the presupposition differently. Presupposition is one of the most important concepts in linguistics. It refers to the implicit inferences made in communication between people. These inferences are necessary to understand the utterances correctly. The research particularly endeavors to focus on the linguistic constructions that activate presupposition.
Background: Restoration of the gingival margin of Class II cavities with composite resin continues to be problematic, especially where no enamel exists for bonding to the gingival margin. The aim of study is to evaluate the marginal leakage at enamel and cementum margin of class II MOD cavities using amalgam restoration and modern composite restorations Filtek™ P90, Filtek™ Z250 XT (Nano Hybrid Universal Restorative) and SDR bulk fill with different restoratives techniques. Materials and method: Eighty sound maxillary first premolar teeth were collected and divided into two main groups, enamel group and cementum group (40 teeth) for each group. The enamel group was prepared with standardized Class II MOD cavity with gingival margin (1 m
... Show MoreOxidative 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 MoreThe 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.