The importance of vibrations in rotating rotors in engineering applications has been examined, as has the best approach to interpreting vibration data. The most extensively used analytical approaches for rotating shaft vibration analysis have been investigated. In this research, a detailed study was made of the Rayleigh and Dunkerley methods due to their importance in the special calculations to find the amplitude of vibrations in the rotation system. The multi-node method was used to calculate both Dunkerley's and Rayleigh's methods. An experimental platform was built to study the vibrations that occur in the rotating shafts, and the results were compared with theoretical calculations and with different distances of the bearings. It proved that there is very little error between the experimental and theoretical results. The vibration signal from the sensors was analyzed using the LABVIEW program. Rayleigh's method was compared to the exact method, and it was considered the most accurate method. It was found that it made very little difference, up to about 0.06%. As for the Dunkerley method, the difference between it and the proper method is about 4%, which is acceptable. Then a comparison was made between Rayleigh's and Dunkerley's methods, and it was found that Dunkerley's method is the most appropriate in the calculations.
Background: Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder affecting women of reproductive age. Oxidative stress may contribute to its pathogenesis. Paraoxonase-1 (PON1) is an antioxidant enzyme associated with high-density lipoprotein, and its genetic polymorphisms may alter enzyme activity. This study aimed to investigate the association between PON1 L55M polymorphism (rs854560) and PCOS in Iraqi women.Methods: This case-control study included 80 women aged 20–35 years who were in good general health and matched for age and body mass index (BMI). Genomic DNA was extracted using a commercial kit. The PON1 L55M polymorphism was amplified by polymerase chain reaction and genotyped by direct sequen
... Show MorePurpose: The research seeks to develop the implications of intellectual human capital, and social capital in business organizations, and will be accomplished on three levels, the first level (the level of description) to identify, diagnose and display content philosophical Strategic Human Resource Management at the thought of modern administrative represented by human capital and Ras social capital. The second level (level of analysis) and the analysis of the extent of the impact of alignment between human capital, and social capital in the organizational strength of the organizations. The third level (Level predict) the formulation of a plan to strengthen the organizational strength in business organizations and to develop speci
... Show MoreWastewater treatment plants operators prefer to make adjustments because they are more cost effective, to use the existing tank instead of building new ones. In this case an imported materials would be used as bio-loads to increase biomass and thus maintain efficiency as the next organic loading increases.In the present study, a local substance "pumice stone" was used as a biological carrier in the aeration tank, and the experiments were carried out in five stages: without biological carriers, filling ratio of 4%,10%,20%, and25% with pumice stone, the maximum organic loading at each stage (1.1884, 1.2144, 1.9432, 2.7768, 3.3141)g BOD /l.d respectively.Other experiments were carried out to determine the best filling ratio, the SS remova
... Show MoreThe molluscicidal effects of herbicide 2, 4-D were studied against tow species of freshwater snail Bulinus truncatus and Melanopsis nodosa by short term experiments. Calculated values of lethal concentrations (LC50 and LC100) were maid to two spices for different period of time 24hr, 48hr, 72hr and 96hr. The study had showed that the herbicide 2, 4-D was toxic against the tow species. The toxicity of the herbicide was low or unknown in low concentrations in the first period of exposure 24and 48hr to two spices but it increase gradually with increase period of exposure. The spice of B.truncatus was more tolerant than the M.nodosa. All the individual of M nodosa was death while in B.truncatus the complete death was not appear until finish the
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This research aims to compare Bayesian Method and Full Maximum Likelihood to estimate hierarchical Poisson regression model.
The comparison was done by simulation using different sample sizes (n = 30, 60, 120) and different Frequencies (r = 1000, 5000) for the experiments as was the adoption of the Mean Square Error to compare the preference estimation methods and then choose the best way to appreciate model and concluded that hierarchical Poisson regression model that has been appreciated Full Maximum Likelihood Full Maximum Likelihood with sample size (n = 30) is the best to represent the maternal mortality data after it has been reliance value param
... Show MoreObjective: This study was designed to investigate some possible therapeutic mechanisms of pentoxifylline and sildenafil in the treatment of colorectal carcinoma induced by 1, 2 dimethylhydrazines in rats. Methods: Rats were allocated into seven groups, negative control, colon cancer induced by 1,2,dimethylhydrazine, 5-fluorouracil (5-FU) (50 mg/kg)-treated, pentoxifylline (PTX) (50 mg/kg)-treated, sildenafil (0.7 mg/kg)-treated groups; the two other groups set as colon cancer induced group treated with PTX (50 mg/kg) plus 5-FU(50 mg/kg) and sildenafil (0.7 mg/kg) plus 5-FU (50 mg/kg), respectively. Results: Biochemical results revealed significant elevation of serum carcinoembryonic antigen (CEA) levels, carbohydrate19-9 antigen (CA19-9) as
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The research aimed to test the relationship between the size of investment allocations in the agricultural sector in Iraq and their determinants using the Ordinary Least Squares (OLS) method compared to the Error Correction Model (ECM) approach. The time series data for the period from 1990 to 2021 was utilized. The analysis showed that the estimates obtained using the ECM were more accurate and significant than those obtained using the OLS method. Johansen's test indicated the presence of a long-term equilibrium relationship between the size of investment allocations and their determinants. The results of th
... Show MoreThe subject of the information technology system ( ITS ) of the important issues And contemporary thought in management, and various types of organizations seeking to apply and try to
... Show MoreThe conjunctive ''and'' and its Arabic counterpart ''و'' are discourse markers that express certain meanings and presuppose the presence of other elements in discourse. They are indispensable aids to both the text writers and readers. The present study aims to show that such cohesive ties help the writer to organize his main argument and communicate his ideas vividly and smoothly. They also serve as explicit signals that help readers unfold text and follow its threads as realized in the progression of context. The researcher has utilized the Quirk Model of Semantic Implication for data analysis. A total of 42 (22 for English and 20 for Arabic) political texts selected from different elite newspapers in both Arabic and English for the analy
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