442 research outputs found

    The Foundation of the Right Bank in Wadi-Zarat Dam

    Get PDF
    The geotechnical engineering characteristics of a calcareous crust formation are evaluated in order to determine the feasibility of its stability under the right bank of Wadi Zarat Dam. The crust is a rock similar, extremely heterogeneous, material with location of collapsing susceptibility when saturated. The formation is caverned and locally very permeable and can present a risk of losing the reservoir water, dissolution, settlement, and piping. In this case study, several alternatives to treat the crust formation are presented, discussed, and compared. Rational justifications for the adopted solution are given and the predicted performance during operation of the dam is provided in order to be compared with the observed behaviour

    Utilization of Synthesized Nano-Zinc Oxide in Yellow Basic Dye Decontamination from Industrial Wastewater

    Get PDF
    ZnO nanorod has been successfully synthesized through the reduction of Zinc chloride salt with ammonia solution in the presence of triethanolamine (TEA) as surfactant agent via hydrothermal technique. The properties of the produced material were determined using different characterization techniques such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared spectrum (FTIR). The results showed that the asprepared ZnO are rod- like morphologies at pH equal to 10. The synthesized nano rod-zinc oxide was employed asadsorbent agent for basic yellow 28 dye decolorization from polluted industrial wastewater. The synthesized nano-ZnO was achieved 93.26% dye decolorization affinity with in 60minutes. The variation in the different processing parameters on the dye sorption process was elucidated using batch technique. The increment in both the dye solution pH and its  temperature was association with decline in the decolourization process. The optimum nano-zinc oxide dosage was recorded to be equal to 10 g/L. The adsorption data at equilibrium were analyzed using Langmuir, Freundlich and Temkin equilibrium isotherms. The experimental results confirmed the applicability of synthesized nano-zinc oxide as adsorbent agent for dye decontamination from polluted wastewater.Keywords: nano-zinc oxide, dye decolourization, sorption parameters

    Incompressible Squeeze-Film Levitation

    Full text link
    Transverse vibrations can induce the non-linear compression of a thin film of air to levitate objects, via the squeeze film effect. This phenomenon is well captured by the Reynolds' lubrication theory, however, the same theory fails to describe this levitation when the fluid is incompressible. In this case, the computation predicts no steady-state levitation, contradicting the documented experimental evidence. In this letter, we uncover the main source of the time-averaged pressure asymmetry in the incompressible fluid thin film, leading the levitation phenomenon to exist. Furthermore, we reveal the physical law governing the steady-state levitation height, which we confirm experimentally

    A temperature characterization of (Si-FinFET) based on channel oxide thickness

    Get PDF
    This paper presents the temperature-gate oxide thickness characteristics of a fin field-effect transistor (FinFET) and discusses the possibility of using such a transistor as a temperature nano-sensor. The investigation of channel oxide thickness–based temperature characteristics is useful to optimized electrical and temperature characteristics of FinFET. Current–voltage characteristics with different temperatures and gate oxide thickness values (Tox = 1, 2, 3, 4, and 5 nm) are initially simulated, and the diode mode connection is considered to measure FinFET’s temperature sensitivity. Finding the best temperature sensitivity of FinFET is based on the largest change in current (∆I) within a working voltage range of 0–5 V. According to the results, the temperature sensitivity of FinFET increases linearly with oxide thickness within the range of 1–5 nm, furthermore, the threshold voltage and drain-induced barrier lowering increase with increasing oxide thickness. Also, the subthreshold swing (SS) is close to the ideal value at the minimum oxide thickness (1 nm) then increases and diverges with increasing oxide thickness. So, the best oxide thickness (nearest SS value to the ideal one) of FinFET under the conditions described in this research is 1 nm

    Lomustine use in combination with etoposide, cytarabine and melphalan in a brief conditioning regimen for auto-HSCT in patients with lymphoma: the optimal dose

    Get PDF
    Univ Fed Juiz de Fora, Div Hematol & Bone Marrow Transplantat, Juiz de Fora, MG, BrazilMed Univ S Carolina, Div Hematol Oncol, Charleston, SC 29425 USAUniv Fed Juiz de Fora, Div Clin Med, Juiz de Fora, MG, BrazilUniversidade Federal de São Paulo, Div Hematol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Hematol, São Paulo, BrazilWeb of Scienc

    Computation of wave dispersion characteristics in periodic porous materials modeled as equivalent fluids

    Get PDF
    This paper starts with the presentation of the shift cell technique, which allows the description of the propagation of all existing waves starting from the unit cell through a quadratic eigenvalue problem. Its major advantage is that it allows the implementation of any frequency dependence and damping in the problem: this is a fundamental advantage when computing the dispersion curves of a porous material modeled as an equivalent fluid. The second part of this work concerns the investigation of the link between the dispersion curves and the acoustic properties of the material. Deriving the equivalent acoustic properties of the unit cell from its dispersion characteristics, indeed, could be a very efficient approach for designing the sound packages with a simple a preliminary eigenvalue analysis. Proceedings of ISMA 2018 - International Conference on Noise and Vibration Engineering and USD 2018 - International Conference on Uncertainty in Structural Dynamics. All rights reserved

    Utilization of Synthesized Nano-Zinc Oxide in Yellow Basic Dye Decontamination from Industrial Wastewater

    Get PDF
    ZnO nanorod has been successfully synthesized through the reduction of Zinc chloride salt with ammonia solution in the presence of triethanolamine (TEA) as surfactant agent via hydrothermal technique. The properties of the produced material were determined using different characterization techniques such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared spectrum (FTIR). The results showed that the as prepared ZnO are rod- like morphologies at pH equal to 10. The synthesized nano rod-zinc oxide was employed as adsorbent agent for basic yellow 28 dye decolorization from polluted industrial wastewater. The synthesized nano-ZnO was achieved 93.26% dye decolorization affinity with in 60minutes. The variation in the different processing parameters on the dye sorption process was elucidated using batch technique. The increment in both the dye solution pH and its temperature was association with decline in the decolorization process. The optimum nano-zinc oxide dosage was recorded to be equal to 10 g/L. The adsorption data at equilibrium were analyzed using Langmuir, Freundlich and Temkin equilibrium isotherms. The experimental results confirmed the applicability of synthesized nano-zinc oxide as adsorbent agent for dye decontamination from polluted wastewater

    Broadly tunable high-power random fibre laser

    Get PDF
    As shown recently, a long telecommunication fibre may be treated as a natural one-dimensional random system, where lasing is possible due to a combination of random distributed feedback via Rayleigh scattering by natural refractive index inhomogeneities and distributed amplification through the Raman effect. Here we present a new type of a random fibre laser with a narrow (∼1 nm) spectrum tunable over a broad wavelength range (1535-1570 nm) with a uniquely flat (∼0.1 dB) and high (>2 W) output power and prominent (>40 %) differential efficiency, which outperforms traditional fibre lasers of the same category, e.g. a conventional Raman laser with a linear cavity formed in the same fibre by adding point reflectors. Analytical model is proposed that explains quantitatively the higher efficiency and the flatter tuning curve of the random fiber laser compared to conventional one. The other important features of the random fibre laser like "modeless" spectrum of specific shape and corresponding intensity fluctuations as well as the techniques of controlling its output characteristics are discussed. Outstanding characteristics defined by new underlying physics and the simplicity of the scheme implemented in standard telecom fibre make the demonstrated tunable random fibre laser a very attractive light source both for fundamental science and practical applications such as optical communication, sensing and secure transmission
    • …
    corecore