In this paper, we studied the spark corona discharge in tap and distillited waters. The results show the shape of cone that generated on the tip of capillary tube is different with conductivity of liquids. The blue glow appears at the end of capillary tube and the drop extends into a cone. In addition, the conducitivity is affected on the relationship between the appearance of the blue glow discharge with the applied voltage. The size of the cone decreases with an increase in applied voltage. The cone diameter at the base of capillary tube oscillates with period approximately 1 Sec. this oscillates in the cone diameters is due to the change distance between the liquid electrode and the surface of liquid. The intensity of spark corona discharge that formed in tap water higher than that formed in distillited water. In addiation, when the applied voltage is 5 KV on distillted water, the drope extends into two cones while in tap water the drop extends into one cone. These contrast between two water types which under test (i.e. tap and distillited waters) is due to the differance in condictivity of water.
This research aimed to identify the level of English language knowledge among the students of scientific colleges and the preparatory year (scholarship students) at the Islamic University of Madinah. The research was limited to identifying students at the meanings of vocabulary and grammar of the English language. The researcher used a descriptive approach to achieve study goals. It applied three tools to collect information from the targeted sample; first, a test for determining the level of students in the achievement of vocabulary which applied to (69) students. Second, a test to determine the level of students in the English language grammar, (73) students took part. Third, a survey to get students’ opinions about the program of te
... Show MoreIn this paper, we deal with a dynamical system that can demonstrate a chaotic attractor of Rossleroscillator. We simulate the Rosslerequations numerically then we investigate the model experimentally. Numerically, the Rossler parameter a and b were fixed and c was changed.The evolution of the system exhibits period, period-doubling, second period doubling, and chaos when control parameters are changed. This evolution can be seen by analyze the time series, the bifurcation diagrams and phase space. Experimentally, the evolution of the system exhibited the same numerical behavior by changing the resistance (Rv) in Rossler circuit that represent as control parameter.
The present paper investigates the role of fear and predator dependent refuge in the prey-predator system. The system describes the interaction between prey and a stage structure of predator that incorporates Holling II functional response. The predator splits into two compartments immature (juvenile) and mature (adult). The mature predators can hunt and reproduce but this capability is not found in the immature predators, the immature depend on their parents. The growth rate of prey decreases due to the existence of mature predators. The existence, uniqueness, and boundedness of the solution of the system are investigated. Three equilibrium points of the system are determined. The local stability of the system is studied. The global stabil
... Show MoreSolar photovoltaic (PV) has many environmental benefits and it is considered to be a practical alternative to traditional energy generation. The electrical conversion efficiency of such systems is inherently limited due to the relatively high thermal resistance of the PV components. An approach for intensifying electrical and thermal production of air-type photovoltaic thermal (PVT) systems via applying a combination of fins and surface zigzags was proposed in this paper. This research study aims to apply three performance enhancers: case B, including internal fins; case C, back surface zigzags; and case D, combinations of fins and surface zigzags; whereas the baseline smooth duct rep
The necessary optimality conditions with Lagrange multipliers are studied and derived for a new class that includes the system of Caputo–Katugampola fractional derivatives to the optimal control problems with considering the end time free. The formula for the integral by parts has been proven for the left Caputo–Katugampola fractional derivative that contributes to the finding and deriving the necessary optimality conditions. Also, three special cases are obtained, including the study of the necessary optimality conditions when both the final time and the final state are fixed. According to convexity assumptions prove that necessary optimality conditions are sufficient optimality conditions.
... Show MoreLaser is a powerful device that has a wide range of applications in fields ranging from materials science and manufacturing to medicine and fibre optic communications. One remarkable
Background: Using dual-energy X-ray absorptiometry, body fat mass has been determined. The assessment of body fat mass was conducted utilizing dual-energy X-ray absorptiometry analysis of the pelvis and vertebral column. While it is acknowledged that osteoporosis can impact both body fat mass and bone mineral density, the particulars of this relationship currently remain uncertain. Objective: The aim of the present investigation is to assess gender differences in the effects of osteoporosis on the body fat mass of the upper and lower extremities. Method: 170 individuals participated (85 males and 85 females) in this study. Patients who presented with bone discomfort consisted of 40 males and 40 females. In addition, 90 apparently he
... Show MoreSarcasm is conceders one patterns of undesirable communication, which causes social problems in humans relationships because of the contradictory verbal and nonverbal expressions is known sarcasm may defined , statements with intent to belittle others in different situations, dealing with the individual deliberately, to diminish the will or overwhelmed by the recipe stupid, which generate a reaction when a person listener, raising the intentions of ridicule and undermine it, and this may happen is different from the irony interest increased in sarcasm since the development of scientists "Watzlawick '" and Bevin "Jackson's" in 1967 theory interactive and considered the sarcasm one interaction patterns in the social relationship, which use
... Show MoreThis paper displays a survey about the laboratory routine core analysis study on ten sandstone core samples taken from Zubair Reservoir/West Quarna Oil Field. The Petrophysical properties of rock as porosity, permeability, grain's size, roundness and sorting, type of mineral and volumes of shales inside the samples were tested by many apparatus in the Petroleum Technology Department/ University of Technology such as OFITE BLP-530 Gas Porosimeter, PERG-200TM Gas Permeameter and liquid Permeameter, GeoSpec2 apparatus (NMR method), Scanning Electron Microscopy (SEM) and OFITE Spectral Gamma Ray Logger apparatus. By comparing all the results of porosity and permeability measured by these instruments, it is clear a significant vari
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