The general approach of this research is to assume that the small nonlinearity can be separated from the linear part of the equation of motion. The effect of the dynamic fluid force on the pump structure system is considered vibrates at its natural frequency but the amplitude is determined by the initial conditions. If the motion of the system tends to increase the energy of the pump structure system, the vibration amplitude will increase and the pump structure system is considered to be unstable. A suitable MATLAB program was used to predict the stability conditions of the pump structure vibration. The present research focuses on fluid pump problems, namely, the role played by damping coefficient C, damping factor D and angular speed ω (termed the ratio () and the determining stability of a centrifugal pump structure. The data demonstrate substantial rotor dynamic effects, a destabilizing chart appears to be inversely proportional to the D, C, and ω, and resonance changes significantly with flow rate.
Polycaprolactone is one of the natural biodegradable polymers mainly used in bioplastics production for packaging, usually composed of non-toxic compounds and biodegradable. The aim was to examine the role of zinc oxide (ZnO) nanopowder on the,wettability , thermal and anti-bacterial effect nanocomposites. Pure PCL and PCL-based bio- nanocomposites doped with various ratios of ZnO nanoparticles from 0% to 5wt% were prepared through the arrangement of throwing procedure. The results show that wettability properties in relation to ideal PCL and that they were increasingly hydrophobic from 57º.8 to 69º.53 because add ZnO nanocomposites,the thermal stability between 300 and 400 ° C makes them perfect for the application
... Show MoreStability of laminated plate under thermal load varied linearly along thickness, is developed using a higher order displacement field which depend on a parameter “m”, whose value is optimized to get results closest to three-dimension elasticity results. Hamilton, s principle is used to derive equations of motion for laminated plates. These equations are solved using Navier-type for simply supported boundary conditions to obtain non uniform critical thermal buckling and fundamental frequency under a ratio of this load. Many design parameters of cross ply and angle ply laminates such as, number of layers, aspect ratios and E1/E2 ratios for thick and thin plates are investigated. It is observed that linear and uniform distribution of
... Show MoreIt is proposed and studied a prey-predator system with a Holling type II functional response that merges predation fear with a predator-dependent prey's refuge. Understanding the impact of fear and refuge on the system's dynamic behavior is one of the objectives. All conceivable steady-states are investigated for their stability. The persistence condition of the system has been established. Local bifurcation analysis is performed in the Sotomayor sense. Extensive numerical simulation with varied parameters was used to explore the system's global dynamics. A limit cycle and a point attractor are the two types of attractors in the system. It's also interesting to note that the system exhibits bi-stability between these 2 types of attractors.
... Show MoreThis study was aimed to investigate the genetic variability of 26 rice genotypes and evaluation at two locations in Sulaimani governorate, Gaba and Chawtan which were completely different in their environmental condition during the season of 2019. The performances of the genotypes were analyzed at both locations as well as the average of both. Simple coefficients of correlation were used to assess the grain yield components and their relationships. Path analysis was used to determine the direct and indirect effects of such components on grain yield plant-1. The genotypes were grouped based on the agro-morphological features using cluster analysis. Almost all of the traits at both locat
... Show MoreComparisons of two life tables constructed to display alfaifa weevil Hypera posticoa (Gryllenhal), populations in southeentral Wisconsin, U. S. A. under epizootic and enzootic conditions of fungal diseasea, caused by Erynia phytonomi Arthur suggests that the “prepupal” stage provided the greates contribution to population changes under both conditions due to the high mortality rate. The principle mortality agents during this stage are E. phytonomi and the parasitoids complex of Bathyp1ectes curculionis and Buthyp1ectes anurus respectively under the two condition.
The research aims to determine the strength of the relationship between time management and work pressure and administrative leadership, where he was taken a sample of (47) of the administrative leadership at the Higher Institute of security and administrative development in the Ministry of Interior was used questionnaire as a key tool in collecting data and information and analyzed the answers to the sample surveyed by using Statistical program (spss) in the arithmetic mean of the calculation and test (t) and the correlation coefficient, the research found the most important results: the existence of significant moral positive relationship between both time management and work pressure and administrative leadership, the leadership of th
... Show MoreThe aim of this study was to compare the effect of conventional implant site preparation technique and a combination of conventional/piezosurgery preparation on implant stability measured at different time intervals, insertion torque, and preparation time. A randomized controlled study was designed, it included 26 patients who received 54 dental implants randomly assigned to 2 groups; in the control group, implants were installed after conventional preparation with drills whereas the study group received implants after mixed conventional/piezosurgery preparation. The outcome variables included: implant stability measured immediately after implant insertion, at 8 weeks and 16 weeks postoperatively, insertion torque and preparation time. All
... Show MoreBringing about urban, economic, and social changes in rural areas similar to those occurring in urban areas aims to reduce urban-rural disparities by providing services in those areas, decentralizing the management of these services, expanding citizen participation in local governance (decentralized administration), and achieving comprehensive development, developing and empowering localities, and keeping pace with new transformations and their impacts on the functions of the center and localities. In fact, the lack of clarity of the role of local government in planning and managing services has hindered development plans, and declined the level of services in rural areas, and has negative
... Show MoreThis research deals with leverage and its impact on the profitability of Islamic banks in Iraq for the years (2015-2018), the research variables of leverage have been analyzed and measured as an independent variable, profitability as a dependent variable, and the research is based on a main hypothesis: there is a moral relationship of statistical significance. Between leverage and profitability at The Islamic Cooperation Bank for the period (2015-2018). The results of the research showed that there are moral (exorcist) relationships between the ratio of leverage and profitability indicators, as the higher the leverage ratio, the higher the profitability indicators. In addition, The Islamic Cooperation Bank has adopted a conservative poli
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