In the current research, the work concentrated on studying the effect of curvature of solar parabolic trough solar collector on wind loading coefficients and dynamic response of solar collector. The response of collector to the aerodynamic loading was estimated numerically and experimentally. The curvature of most public parabolic trough solar collectors was investigated and compared. The dynamic response of solar collector due to wind loading was investigated by using numerical solution of fluid-structure interaction concept. The experimental work was done to verify the numerical results and shows good agreement with numerical results. The numerical results were obtained by using finite element software package (ANSYS 14). It was found that the change in collector curvature (focal length) lead to remarkable changes in wind loading coefficients (drag, lift, and moment), dynamic response (displacement) and natural frequencies but does not affect the first mode shape.
Germination and field emergence are delayed and their duration is prolonged due to the declining soil temperature during the spring season, which is reflected in the subsequent stages of crop growth, therefore, this study aimed to improve germination. Under a wide range of environmental conditions, a laboratory factorial experiment was carried out to study the effect of seed stimulation with potassium nitrate (distilled water only (0), 2, 4, and 6 mg L-1) and with an aqueous extract of licorice roots (distilled water only (0), 3, 6, and 9 g L-1) on the seed viability and vigor. The laboratory experiment was carried out according to the Completely Randomized Design (CRD) with four repetitions. The results showed the superiority of the intera
... Show Moreم.د. فاطمة حميد ،أ.م.د وفاء صباح محمد الخفاجي, International Journal of Psychosocial Rehabilitation,, 2020 - Cited by 1
In this research work an attempt has been made to investigate about the Robustness of the Bayesian Information criterion to estimate the order of the autoregressive process when the error of this model, Submits to a specific distributions and different cases of the time series on various size of samples by using the simulation, This criterion has been studied by depending on ten distributions, they are (Normal, log-Normal, continues uniform, Gamma , Exponential, Gamble, Cauchy, Poisson, Binomial, Discrete uniform) distributions, and then it has been reached to many collection and recommendations related to this object , when the series residual variable is subject to each ( Poisson , Binomial , Exponential , Dis
... Show MoreMicrowave heating is caused by the ability of the materials to absorb microwave energy and convert it to heat. The aim of this study is to know the difference that will occur when heat treating the high strength aluminum alloys AA7075-T73 in a microwave furnace within different mediums (dry and acidic solution) at different times (30 and 60) minutes, on mechanical properties and fatigue life. The experimental results of microwave furnace heat energy showed that there were variations in the mechanical properties (ultimate stress, yielding stress, fatigue strength, fatigue life and hardness) with the variation in mediums and duration times when compared with samples without treatment. The ultimate stress, yielding stress and fatigue streng
... Show MoreTo study the qualitative changes in testis tissue after carbon tetrachloride (CCl4) administration and to determine whether citric acid (CA) has a protective effect against testis damage induced by CCl4. This study compared two types of CA by measuring the histoarchitecture of the testis and serum levels of progesterone, estrogen and testosterone on mice. One of the most produced organic acid is citric acid. In this study, CA produced by microbial fermentation using Aspergillus Niger 5mg/kg and derived from citrus limon 400mg/kg (lemon). Mice were treated with daily intraperitoneal (i.p.) injection for seven successive days after randomly separated into six groups: (1) control, (2) CCl4 (0.02%), (3) limon citric acid (400 mg/kg), (4) CCl4 (
... Show MoreScientific research on the environment of the Iraqi marshes, its beauty and its characteristics is considered one of the most important functions of Iraqi universities and scientific institutions, because of its great historical impact related to the identity of Iraq and the Iraqis and the basis of science and science, through which the first letter and the first human civilizations were established and in the same importance technical research is among the most important functions of departments Institutes and colleges of the arts, research centers and museums inside and outside Iraq. Also, research centers specialized in the natural environment of Iraq, including the marshes. Therefore, it is hoped that this research will develop the a
... Show MoreTeaching through the system of personal learning, known as (Clare's plan) is amongst the most prominent plans which depend on self-education, as it received worldwide recognition. The plan lets the learner achieve learning by depending on himself after being familiar with the educational goals given to him, then he starts to solve the exercises and the drills accompanying the unit. After that, he checks his achievement by answering the self-evaluation tests. This method offers more opportunities for personal interaction than do the traditional systems, and individual leaning is a methodical expression aims at taking care of the learner and making him the locus of the processes of teaching and learning.
Aims of the study
... Show MoreThe technique of plant tissue culture has been used to In vitro micropropagation of Spilanthes acmella (L.) Murr. It is an ornamental and medicinal plant not cultivated in Iraq. Seeds were sterilized and cultuared on full strength Murashige and Skoog medium(1962)(MS). Naphthalene acetic acid (NAA), 6- furfuryl aminopurine (Kin.) growth regulators were used at the Initiation stage.The combination between IAA and Kin. was used in multiplication stage. IAA was used for rooting the shoots. Results showed that 1.5% sodium hypochlorite for 15 min was very effective for disinfecting and survival. Nodes exhibited relatively highest response as compared with apical meristems and leaflets culture. Supplying the culture medium with 1 mg/L.
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