This research introduces a developed analytical method to determine the nominal and maximum tensile stress and investigate the stress concentration factor. The required tooth fillets parametric equations and gears dimensions have been reformulated to take into account the asymmetric fillets radiuses, asymmetric pressure angle, and profile shifting non-standard modifications. An analytical technique has been developed for the determination of tooth weakest section location for standard, asymmetric fillet radiuses, asymmetric pressure angle and profile shifted involute helical and spur gears. Moreover, an analytical equation to evaluate gear tooth-loading angle at any radial distance on the involute profile of spur and helical gears, (taking into account the effect of profile shift factor) has been derived. In addition, numerical solution for the evaluation of the maximum fillet tensile stress and the combined tensile stress concentration factor for the verification of the analytical method using computer-aided engineering software (ANSYS Version 18.1). The analytical and FE result have been compared and found to be very close. The most effective method for reducing the stress concentration factor have been found by applying negative profile shifting on asymmetric tooth with lower unloaded pressure angle and high loaded pressure angle and fillet radius, which can lead to an enhancement percentage of (20%) when using a (35o/20o) asymmetric spur gear of a (24) teeth number with a shift factor of (-0.3mo) compared with standard (20o) one.
Abstract
At any moment, the continuous usage of medications can accompanied by DNA damage and the accumulation of such damages can cause serious consequences. Antidepressants are long-term used drugs and the incidence of their genotoxic impacts cannot be excluded. Therefore, this work was designed to investigate the possible genotoxic effects of the commonly used antidepressants (fluoxetine and amitriptyline) in adult male rats.
Detection of DNA damage in individual cells was assessed by comet and micronucleus assays in three different cell populations i.e. liver, testis and bone marrow tissues of 24 swiss albino adult male rats. The animals were randomly allocated into three groups of 8 rats ea
... Show MoreThese factors, as well as disasters and wars that the Arab homeland exposed to and still under this exposure, in addition to the severe stress upon.
Iraqi Academics have been subjected to direct consequences of 2003 war. Exact figures are not known. It was mentioned. Many people were killed, sacked from their academics jobs, threatened to leave directly or indirectly their jobs, houses, and Iraq. Others have been imprisoned, tortured, or kidnapped / threatened to be kidnapped etc. Their families have been subjected to similar traumatic experiences or threats. All theses stressors may have lead to Post Traumatic (PTSD) Experiences. These Traumatic experiences have lead to Dislocation, relocation and Immigration etc. All sectors of
... Show MoreType 2 daibetes mellitus (T2DM) is a global concern boosted by both population growth and ageing, the majority of affected people are aged between (40- 59 year). The objective of this research was to estimate the impact of age and gender on glycaemic control parameters: Fasting blood glucose (FBC), glycated hemoglobin (HbA1C), insulin, insulin resistance (IR) and insulin sensitivity (IS), renal function parameters: urea, creatinine and oxidative stress parameters: total antioxidant capacity (TAC) and reactive oxygen species (ROS). Eighty-one random samples of T2DM patients (35 men and 46 women) were included in this study, their average age was 52.75±9.63 year. Current study found that FBG, HbA1C and IR were highly significant (P<0.01) inc
... Show MoreA biostimulant is any microorganism or substance used to enhance the efficiency of nutrition, tolerance to abiotic stress and/or quality traits of crops, depending on its contents from nutrients. Plant biostimulants like honey bee (HB) and silymarin (Sm) are a strategic trend for managing stressed crops by promoting nutritional and hormonal balance, regulating osmotic protectors, antioxidants, and genetic potential, reflecting plant growth and productivity. We applied diluted honey bee (HB) and silymarin-enriched honey bee (HB- Sm) as foliar nourishment to investigate their improving influences on growth, yield, nutritional and hormonal balance, various osmoprotectant levels, different components of antioxidant system, and genetic p
... Show MoreIt is very well known in the planning publications that when creating spacing development to a region or sub-region, it can be able to make more than an alternative consisting with the strategic directions overtaken from the actual development of region and the situational and developmental objectives needed. However, the difficulty facing the situational planning is in selecting one of these alternatives to be the best in order to make a balanced situational re-structure, and achieving the economic, social and civil objectives. The developmental situation elements in the regions and governorates, including (Karbala) impose themselves as situational power which implies the process of re-structural arrangement where the situational develo
... Show MoreThe PET scans provide images that pinpoint the anatomic location of abnormal metabolic activity within the body. A radionuclide suitable for labeling a wide range of radiopharmaceuticals for positron emission tomography imaging is used also for local therapy of tumors. Among the possible methods for cyclotron production of radionuclide used in PET. We investigate the proton irradiation to produce the standard radionuclide (15O, 11C,1 3N, 18F) and some non-standard Radionuclide (76Br,124I,60Cu,66Ga,86Y and 89Zr). The total integral yield based on the main published and approved experimental results of excitation functions were calculated.
Is the chemical industries of great importance for the economy of any country, through what is borne by these industries is an important part of the changes contained in the industrial output of transfer and, moreover, that these industries are overlaps and intricacies of sector-wide with the rest of the manufacturing sectors, with agriculture and services , through the offering of these industries produce Production requirements intervention such as chemical fertilizer used in the production of agricultural crops, in addition to the various areas for the use of phosphorus in the food industry, to the extent that it is difficult to find material Food preparation is not included i
... Show MorePrevious studies in Euro-American countries have shown that patients with chronic hepatitis C virus infection have increased levels of neuropsychiatric symptoms. While chronic hepatitis C virus infection has been reported in Arab countries such as Iraq, there is little studies about the neuropsychological burden associated with chronic hepatitis C among patients in the Arab region. The aim of the current study was to measure the prevalence and level of severity of depression, anxiety and stress among a sample of chronic hepatitis C patients in AL-Najaf province /Iraq. The current study was cross-sectional study carried out on (110) already diagnosed chronic viral hepatitis C patients who attended the Gastroenterology and Hepatology
... Show MoreGlass fiber–reinforced polymer (GFRP) reinforcement provides an effective alternative to conventional steel in concrete structures due to its corrosion resistance. Nevertheless, the lower elastic modulus of GFRP necessitates careful consideration of serviceability behavior in GFRP-reinforced concrete members. This study presents a numerical sectional analysis model for predicting the flexural response and ultimate capacity of hybrid reinforced concrete beams incorporating embedded GFRP profiles in combination with either mild steel or GFRP reinforcement bars under monotonic static loading. The proposed model employs realistic nonlinear stress–strain relationships for concrete and steel, together with secant moduli of elasticity
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