402 research outputs found

    Effect of oil mass flow rate on temperature profile in oil wells

    Get PDF
    In several design calculations including the development of programs to optimize production, engineers and scientists require accurate prediction of temperature drop due to flow in oil wells. The purpose of this research is to create mathematical models to predict the effect of oil mass flow rate on temperature distribution in oil wells. A numerical mathematical model is developed to study the parameters affecting the dynamic and static temperature profiles in oil wells in production and shutting operation. The temperature distribution of the oil from the reservoir to the surface and the temperature distribution in the wall tubing of the oil well and casing, cement sheaths, and surrounding formation is studied. The natural flow of oil wells in Alwahat area located 70 Kilometres south of Marada area east of Libya in the Zaggut field called (6Q1-59) is taken as a study case. In production case, different mass flow rates in winter and summer seasons are studied. The temperature profile in the horizontal direction is estimated at different depths. The Results show that the surface temperature of crude oil increases with the rise in mass flow rate

    Effect of higher salinities on growth and survival of pacific white shrimp, Litopenaeus vannamei (Boone, 1931)

    Get PDF
    The growth and survival of Litopenaeus vannamei post larvae was measured in controlled different salinities condition 35ppt (T1), 40ppt (T2), 45ppt (T3) and 50ppt (T4) were maintained. Group of Shrimp post larvae (weight 0.032 g ± 0.002) were stocked at a density of 35 nos. /aquarium in above salinity ranges. Animals were fed with commercial feed (35% Crude Protein) @ 5% of body weight four times a day. The results indicate that higher SGR was observed in T2 (1.99±0.08) followed by T1 (1.75±0.07), T3 (1.54±0.06) and T4 (1.49±0.17). Highest survival (100 %) was recorded in T1 followed by T2 (96.42%), T3 (94.99%) and T4 (74.21%). From the results of the present study it could be seen that higher salinity significantly reduced the growth and survival of L. vannamei but will also open study area of physiological adaption of animal at higher saline water in performance of organisms

    Efficiency enhancement of photovoltaic performance of quasi-solid state dye sensitized solar cell with TPAI and KI binary iodide salt mixture

    Get PDF
    Quasi-solid-state dye-sensitized solar cells have drawn the attention of scientists and technologists as a potential candidate to supplement future energy needs. The conduction of iodide ions in quasi-solid-state polymer electrolytes and the performance of dye sensitized solar cells (DSSCs) containing such electrolytes can be enhanced by incorporating iodides having appropriate cations. Gel-type electrolytes, were prepared by solution cast technique, based on PVP-co-VAc + PMMA host polymers and mixture of salts Potassium iodide (KI) and tetrapropyl ammonium iodide (TPAI) salts have been used to provide the conducting ions. The salt composition in the binary mixture was varied in order to optimize the performance of solar cells. The electrochemical impedance spectroscopy (EIS) measurements showed that the electrolyte (C6) which contain (KI%25: 5%TPAI) have highest conductivity S/cm at 298 K. The DSSCs with TPAI or KI as the only iodide salt showed the efficiencies 4.136%and 2.532 %, respectively, under AM 1.5(1000 Wm-2) illumination  while the DSSC with mixed cations with (TPAI25%:KI5%) molar ratio shows the  efficiency of 3.179%. Keywords: Binary Iodide, Gel Polymer Electrolyte, Dye-Sensitized Solar Cells, Electrochemical Impedance Spectroscopy

    Preparation and Characterization of Poly(1-vinylpyrroli done-co-vinyl acetate)/Poly(methyl methacrylate) Polymer Electrolyte based on TPAI and KI

    Get PDF
    Polymer electrolytes are promising materials for electrochemical device applications, such as , high energy density rechargeable batteries, supercapacitors, fuel cells, electrochromic displays, etc. Polymer blend electrolytes based on (PVP-co-VAc) and ( PMMA) with different weight ratio of Tetra propyl ammonium iodide (TPAI) and Potassium iodide (KI),  salts using DMSO as solvent. The gel electrolytes were  prepared by solution cast technique. More details can be found in the full paper. Keywords: Gel electrolyte ,Electrochemical Impedance Spectroscopy , Poly(1-vinylpyrrolidone-co- vinyl acetate), poly(methyl meth acryl ate), FTIR

    Search for dark matter with a 231-day exposure of liquid argon using DEAP-3600 at SNOLAB

    Get PDF
    DEAP-3600 is a single-phase liquid argon (LAr) direct-detection dark matter experiment, operating 2 km underground at SNOLAB (Sudbury, Canada). The detector consists of 3279 kg of LAr contained in a spherical acrylic vessel. This paper reports on the analysis of a 758  tonne⋅day exposure taken over a period of 231 live-days during the first year of operation. No candidate signal events are observed in the WIMP-search region of interest, which results in the leading limit on the WIMP-nucleon spin-independent cross section on a LAr target of 3.9×10−45  cm2 (1.5×10−44  cm2) for a 100  GeV/c2 (1  TeV/c2) WIMP mass at 90% C.L. In addition to a detailed background model, this analysis demonstrates the best pulse-shape discrimination in LAr at threshold, employs a Bayesian photoelectron-counting technique to improve the energy resolution and discrimination efficiency, and utilizes two position reconstruction algorithms based on the charge and photon detection time distributions observed in each photomultiplier tube

    The effect of non-conservative compressive force on the vibration of rotating composite blades

    Get PDF
    This paper investigates the effectiveness of a resonance avoidance concept for composite rotor blades featuring extension–twist elastic coupling. The concept uses a tendon, attached to the tip of the blade, to apply a proper amount of compressive force to tune the vibration behavior of the blade actively. The tendon is simulated by applying a non-conservative axial compressive force applied to the blade tip. The main load carrying part of the structure is the composite spar box, which has an antisymmetric layup configuration. The nonlinear dynamic behavior of the composite blade is modelled by using the geometrically exact fully intrinsic beam equations. The resulting nonlinear differential equations are discretized using a time–space scheme, and the stationary and rotating frequencies of the blade are obtained. It is observed that the proposed resonance avoidance mechanism is effective for tuning the vibration behavior of composite blades. The applied compressive force can shift the frequencies and the location at which the frequency veering take place. Furthermore, the compressive force can also cause the composite blade to get unstable depending on the layup ply angle. Finally, the results, highlighting the importance of compressive force and ply angle on the dynamic behavior of composite blades, are presented and discussed

    Electromagnetic backgrounds and potassium-42 activity in the DEAP-3600 dark matter detector

    Get PDF
    See full article for abstrac

    Elastomer-based skins for morphing aircraft applications: Effect of biaxial strain rates and prestretch

    Get PDF
    There is an emerging trend in the morphing aircraft research where two or more morphing degrees of freedom are used on a wing which leads to the concept of polymorphing. The skin of the morphing wing must be flexible in the morphing direction but stiff in other directions to withstand the aerodynamic loads and maintain the airfoil shape. Polymorphing changes the loadings profile (from uniaxial to biaxial) and increases the complexity of designing suitable morphing skins. Furthermore, elastomeric materials used on morphing wings are usually prestretched to prevent wrinkling and to increase their out-of-plane stiffness. This paper focuses on elastomeric morphing skins and it studies the effect of biaxial strain rates and prestretch ratios on important mechanical properties such as stiffness, hysteresis losses (%), and stress relaxations (%) from an experimental perspective. Three polymeric materials are considered: Latex, Oppo, and Ecoflex. This study provides a mechanical comparative understanding of the three polymers used in the morphing wing under biaxial loading (two morphing degrees of freedom)
    corecore