314 research outputs found

    Local Jordanian Materials to Produce a Bakelite-base Construction Composite Material

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    In this investigation, a combined experimental approach of micro-structural observation and compressive load capacity testing were followed to determine the behavior of bakelite matrix material reinforced with Jordanian silica sand. It was found that the reinforced samples gave a higher maximum load capacity than the pure matrix, because the homogeneous structure helped in distributing the applied load between the matrix and the reinforcement. Moreover, the higher the volume fraction of the reinforcement, the higher the maximum load capacity of the composite. The maximum load capacity of the samples with 75% content of Jordanian silica sand was less than that of pure bakelite. On the other hand, the higher the particle size of the reinforcement, the higher the maximum load capacity of the composite. Composites of bakelite matrix gave a higher maximum load capacity than that of polystyrene matrix. In addition, a longitudinal brittle fracture was observed for the composites

    ExoMol molecular line lists - XVII The rotation-vibration spectrum of hot SO3_3

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    Sulphur trioxide (SO3_3) is a trace species in the atmospheres of the Earth and Venus, as well as well as being an industrial product and an environmental pollutant. A variational line list for 32^{32}S16^{16}O3_{3}, named UYT2, is presented containing 21 billion vibration-rotation transitions. UYT2 can be used to model infrared spectra of SO3_3 at wavelengths longwards of 2 μ\mum (ν<5000\nu < 5000 cm−1^{-1}) for temperatures up to 800 K. Infrared absorption cross sections are also recorded at 300 and 500 C are used to validate the UYT2 line list. The intensities in UYT2 are scaled to match the measured cross sections. The line list is made available in electronic form as supplementary data to this article and at \url{www.exomol.com}.Comment: 15 pages, 10 figures, 9 tables MNRAS submitte

    CFRP strengthened continuous concrete beams

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    Detection and Identification of Helicobacter pullorum in Poultry Species in Upper Egypt

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    This work aimed to detect, identify and study the epidemiology of Helicobacter pullorum in avian species in Upper Egypt. A total of 1800 samples, including cloacal swabs, cecal swabs and livers were collected from chickens, turkeys and ducks in five different governorates in Upper Egypt. Using conventional phenotypic methods for isolation and identification, Helicobacter pullorum could be identified only from chickens with percentage 39.33% and no presence of the organism in turkeys and ducks. Sixteen randomly selected phenotypically identified Helicobacter pullorum isolates were confirmed using PCR assay based on 16S rRNA gene. In conclusion, conventional phenotypic methods for detection and differentiation of Helicobacter pullorum are often hampered by many limitations, while molecular methods, and PCR, in particular, have marked an important step forward in bacterial diagnostics and can provide a sensitive and rapid alternative method for detection and identification and highlights the potential of PCR technology in routine detection and identification of pathogens

    ExoMol molecular line lists - XVII. The rotation-vibration spectrum of hot SO3

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    Sulphur trioxide (SO3) is a trace species in the atmospheres of the Earth and Venus, as well as being an industrial product and an environmental pollutant. A variational line list for 32S16O3, named UYT2, is presented containing 21 billion vibration–rotation transitions. UYT2 can be used to model infrared spectra of SO3 at wavelengths longwards of 2 μm (ν < 5000 cm−1) for temperatures up to 800 K. Infrared absorption cross-sections recorded at 300 and 500 C are used to validate the UYT2 line list. The intensities in UYT2 are scaled to match the measured cross-sections. The line list is made available in electronic form as supplementary data to this article and at www.exomol.com

    Design and experimental verification of a 50 kW interior permanent magnet synchronous machine

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    This paper presents the design details for an IPM machine designed to deliver 50 kW constant power over a 5:1 speed range extending from 850 rpm to 4250 rpm, with a gradual reduction in the required output power up to 8000 rpm (25 kW). Electromagnetic, thermal, and structural considerations have been included in the design optimization process. The resulting machine is designed with two magnet layers per pole and a distributed stator winding. Special features of the machine include its deep stator slots and four-layer winding, made necessary by the desire to minimize the machine's moment of inertia. Test results available to date demonstrate that the machine is capable of delivering the required output torque and power, and the agreement between the predicted and measured machine parameters is generally quite good. Calculated iron losses for high-speed flux-weakening operation are presented in the final section of the paper, illustrating the challenges associated with minimizing the impact of high-frequency harmonic flux density components.Jahns, T.M.; Seok-Hee Han; El-Refaie, A.M.; Jei-Hoon Baek; Aydin, M.; Guven, M.K.; Soong, W.L

    CFRP strengthened continuous concrete beams.

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    yesThis paper reports the testing of five reinforced concrete continuous beams strengthened in flexure with externally bonded carbon-fibre-reinforced polymer (CFRP) laminates. All beams had the same geometrical dimensions and internal steel reinforcement. The main parameters studied were the position and form of the CFRP laminates. Three of the beams were strengthened using different arrangements of CFRP plate reinforcement, and one was strengthened using CFRP sheets. The performance of the CFRP-strengthened beams was compared with that of an unstrengthened control beam. Peeling failure was the dominant mode of failure for all the strengthened beams tested. The beam strengthened with both top and bottom CFRP plates produced the highest load capacity. It was found that the longitudinal elastic shear stresses at the adhesive/concrete interface calculated at beam failure were close to the limiting value recommended in Concrete Society Technical Report 55

    Differentiation of Infectious Bursal Disease Virus (IBDV) Strains in Experimentally Infected Chickens

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    Infectious bursal disease (IBD) is an acute, highly contagious, and immunosuppressive avian disease caused by IBD virus (IBDV). Differentiation of IBDV strains is crucial for effective vaccination programs and epidemiological investigations. In this study, a combination of clinical, histopathological examinations, immunohistochemistry and indirect immunofluorescence techniques were used to differentiate different IBDV strains. Sixty three weeks old chickens were divided randomly into five equal groups. Chickens of four groups were inoculated orally with different strains of IBDV. Chickens of the fifth group were kept as a control. Three chickens per group were euthanized at 3, 7, 14, 21 days post-inoculation (dpi). Euthanized chickens subjected to autopsy and tissue samples were collected in 10% neutral-buffered formalin for histopathology, immunohistochimestry and immunoflrourescence. The results revealed that clinical examination and histopathology cannot be used alone for differentiation of IBDV strains, while immunohistochemical and immunofluorescence techniques are reliable tools for differentiation of IBDV strains

    3D thermal analysis of a permanent magnet motor with cooling fans

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    Overheating of permanent magnet (PM) machines has become a major technical challenge as it gives rise to magnet demagnetization, degradation of insulation materials, and loss of motor efficiency. This paper proposes a state-of-the-art cooling system for an axial flux permanent magnet (AFPM) machine with the focus on its structural optimization. A computational fluid dynamics (CFD) simulation with thermal consideration has been shown to be an efficient approach in the literature and is thus employed in this work. Meanwhile, a simplified numerical approach to the AFPM machine with complex configuration in 3D consisting of conduction, forced convection, and conjugate heat transfer is taken as a case study. Different simplification methods (including configuration and working conditions) and two optimized fans for forced convection cooling are designed and installed on the AFPM machine and compared to a natural convection cooling system. The results show that the proposed approach is effective for analyzing the thermal performance of a complex AFPM machine and strikes a balance between reasonable simplification, accuracy, and computational resource
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