The effect of internal acoustic excitation on the leading-edge, separated boundary layers and the aerodynamic performance of NACA23015 cross section airfoil are examined as a function of excitation location with ranging frequency range (50-400) Hz of the introduced acoustic. Tests are separately conducted in two sections, open type wind tunnels at the Reynolds number of 3.3x105 for measurement at angle of attack (0, 3, 6, 9 &12) deg. and 3x104 for the visualization at angle of attack (12) deg. based on the airfoil chord. Results indicated that the excitation frequency and the excitation location are the key parameters to alter the flow properties and thus to improve the aerodynamic performance. The most effective excitation frequency is found to be equal to the shear layer instability frequency and on excitation location close to the separation point. Moreover, the lift is increased and drag reduced dramatically. The corresponding boundary layers are visualized to be reattached to the surface.
the effecth of some chemicals on growth of two azotobacter chroococcum and aniline caused significant increase of growth
This Study is conducted to evaluate effects of (leaves, fruits) powder and (oil, alcohol) extract of Coriander (Coriandrum sativum) plant on some biological and physiological aspects of House fly, Musca domestica at laboratory conditions. Result show that these preparations caused biological effects represented in high dead percentage in second instar, fed on different concentrations of food treated with them reached to 27.6, 55.3 at concentration 20% of leaf and fruit powder respectively and 67.3, 77.2% at 10% of oil and alcohol extract of fruit, respectively. Furthermore, study also show reduction in pupation and adults emergence percentage. However, leafs powder had slighter effect than powder and extract of fruit of tested plant. The st
... Show MoreThis study was conducted to evaluate the effects of black tea on Pseudomonas
aeruginosa isolated from eye infection. One hundred samples (corneal scrapings)
were obtained. Approximately, 77% of the cases were due to contact lens wear
followed by 15 % trauma and 8% with unknown history. The isolates identified as
P. aeruginosa were 30% (23/77 CL) and 25% (2/8 Unknown). On the other hand,
the Kirby-Bauer antibiotic sensitivity assay showed that 100% of the isolates were
sensitive to Neomycin, Gentamicin and Amikacin. While 91.6% were sensitive to
Carbenicillin and Ceftriaxone; 66.6% were sensitive to Cefotaxime and 0% were
sensitive to Tertacycline. Only two isolates were found to be multidrug resistant.
Screenin
Radio protective effects of metformin and its ability to alter the spontaneous and induced genotoxic and cytotoxic levels effects on human peripheral blood lymphocytes were investigated in this study. Metformin, a hypoglycemic oral drug, is a biguanide derived from Galega officinalis that is widely utilized in controlling type 2 diabetes mellitus. Whole blood samples from 10 healthy donors (5 males and 5 females) were exposed to two doses of gamma-rays (1 and 2 Gray). Lymphocytes in cultures were treated with metformin (10 and 50µM) before gamma-irradiation. Cytokinesis-block micronucleus test was used to evaluate the protective effects of metformin on radiation induced genomic damage, cytostasis and
... Show MoreBenthic invertebrates' diversity and some physical a:1d
chemical characteristics in Lower Zab tributary and Tigris River were studied. Month l y samples were col l ected from November 2001 to October 2002.
The rt:sLllts of the present study showed the turbidity iu Tigris river
before the confluence to be higher (34.4 NTU) compared to the other stations. Mean salinity was greater in Lower Zab tributary (0.33 %) compared to that in the river. Lower Zab tJibutary and Tigris River were good in Oxygen content, and a high dissolved oxygen value was recorded (7.9 mg/L) in Lower Zab tributary.
... Show MoreABSTRACT: BACKGROUND: Estrogens has traditionally been known as the female hormone, but this idea has been challenged in early 1990’s and an essential physiological role for estrogen in male fertility was identified. Phytoestrogens are naturally occurring non-steroidal plant chemicals that can act like the female hormone estrogen. The herbs ( anise alfalfa and vervain ) chosen in this study contain phytoestrogens. OBJECTIVE: Previous studies demonstrated controversy of the effects of phytoestrogens on the rat testes .Hence, the present investigation was undertaken to investigate the influence of typical dose of herbs containing phytoestrogen on the rat testis. MATERIALS AND METHODS: Twenty-four apparently normal mature male rats we
... Show MoreTillage tools are subject to friction and low-stress abrasive wear processes with the potential deterioration of the desired soil quality, loss of mechanical weed efficacy, and downtime for replacing worn tools. Limited experimental methods exist to quantify investigate the effect of wear-resistant coatings on shape parameters of soil-engaging tools. ASTM standard sand/rubber wheel abrasion and pin-on-disk tests are not able to simulate wear characteristics of the complex shape of the tillage tools. Even though the tribology of tillage tools can be realistic from field tests, tillage wear tests under field conditions are expensive and often challenging to generate repeatable engineeri
Soil bacteria play an interesting role in the reduction of Ag+ ions and the formation of silver nanoparticles (AgNPs), which may be a good source for nanoparticles and play a major role in nanotechnology applications. The concept of this project was to study the effects of these environmentally produced nanoparticles on the growth of some pathogenic bacteria. The environmental bacteria were isolated from soil, purified on broth cultures, and centrifuged, while the supernatant was extracted to detect its ability to convert silver nitrate to nanoparticles. The AgNPs was detected by Atomic Force Microscopy (AFM), while Granularity Cumulating Distribution (GCD) was employed to estimate the AgNPs sizes. The results showed the
... Show MoreObjective: To determine the effectiveness of hypothermia on renal functions for patients undergoing
coronary artery bypass graft CABG surgery.
Methodology: A purposive (non-probability) sample of (50) patients undergoing Isolated coronary artery
bypass graft surgery consecutively admitted to the surgical ward, and they were followed up in the
intraoperative, Intensive Care Unit (ICU) and in the postoperative (surgical ward). Post-operative renal function
test (glumeruler filteration rate (GFR) by using the Crockroft-Gault formula and serum creatinine level) was
determined first week post operative and post operative renal function was classified on the base of peak of
the serum creatinine level and decline of glomeru