10,978 research outputs found

    Multiphoton excitations in vibrational rotational states of diatomic molecules in intense electromagnetic field

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    A theory is presented and a calculational procedure is outlined for evaluating transition amplitudes of multiphoton excitations of vibrational-rotational levels in diatomic molecules. This theory can be utilized in studying behavior of molecules in intense electromagnetic fields

    High yield fusion in a Staged Z-pinch

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    We simulate fusion in a Z-pinch; where the load is a xenon-plasma liner imploding onto a deuterium-tritium plasma target and the driver is a 2 MJ, 17 MA, 95 ns risetime pulser. The implosion system is modeled using the dynamic, 2-1/2 D, radiation-MHD code, MACH2. During implosion a shock forms in the Xe liner, transporting current and energy radially inward. After collision with the DT, a secondary shock forms pre-heating the DT to several hundred eV. Adiabatic compression leads subsequently to a fusion burn, as the target is surrounded by a flux-compressed, intense, azimuthal-magnetic field. The intense-magnetic field confines fusion α\alpha-particles, providing an additional source of ion heating that leads to target ignition. The target remains stable up to the time of ignition. Predictions are for a neutron yield of 3.0×10193.0\times 10^{19} and a thermonuclear energy of 84 MJ, that is, 42 times greater than the initial, capacitor-stored energy

    Effect of pulsed power on particle matter in diesel engine exhaust using a DBD plasma reactor

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    Nonthermal plasma (NTP) treatment of exhaust gas is a promising technology for both nitrogen oxides (NOX) and particulate matter (PM) reduction by introducing plasma into the exhaust gases. This paper considers the effect of NTP on PM mass reduction, PM size distribution, and PM removal efficiency. The experiments are performed on real exhaust gases from a diesel engine. The NTP is generated by applying high-voltage pulses using a pulsed power supply across a dielectric barrier discharge (DBD) reactor. The effects of the applied high-voltage pulses up to 19.44 kVpp with repetition rate of 10 kHz are investigated. In this paper, it is shown that the PM removal and PM size distribution need to be considered both together, as it is possible to achieve high PM removal efficiency with undesirable increase in the number of small particles. Regarding these two important factors, in this paper, 17 kVpp voltage level is determined to be an optimum point for the given configuration. Moreover, particles deposition on the surface of the DBD reactor is found to be a significant phenomenon, which should be considered in all plasma PM removal tests

    Magnetotail structures in a simulated Earth's magnetosphere

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    The structure of the magnetotail is investigated in a laboratory simulated magnetosphere. Particular emphasis is placed on the region of distant magnetotail where the closed field line region of the plasma sheet terminates and the process of reconnection takes place. Our study builds upon the previous investigation of the magnetotail where the main results were based on the magnetic field measurements in the tail region of the simulated magnetosphere. In this paper, more elaborate measurements of plasma flow and electric field are presented. Besides these measurements, this region of distant magnetotail is also explored by high resolution imaging with a gated optical imager (GOI) and by digital image analysis. These images clearly reveal a Y-type magnetic neutral line for the northward 'interplanetary' field (IMF) and a usual X-type for the southward IMF that confirms our previous results deduced from the magnetic field measurements. In the neighborhood of these neutral points a strong component of dawn to dusk electric field (E(sub y)) and a counterstreaming plasma flow is also observed. Plasma flow is measured by using a double sided Faraday cup which is also used to measure the y-component of tail current (J(sub y)) at different locations. These measurements reveal that the tail current is not carried by ions as previously thought, rather it is carried by electrons alone

    Forecasting wind speed data by using a combination of ARIMA model with single exponential smoothing

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    Wind serves as natural resources as the solution to minimize global warming and has been commonly used to produce electricity. Because of their uncontrollable wind characteristics, wind speed forecasting is considered one of the best challenges in developing power generation. The Autoregressive Integrated Moving Average (ARIMA), Simple Exponential Smoothing (SES) and a hybrid model combination of ARIMA and SES will be used in this study to predict the wind speed. The mean absolute percentage error (MAPE) and the root mean square error (RMSE) are used as measurement of efficiency. The hybrid model provides a positive outcome for predicting wind speed compare to the single model of ARIMA and SES

    Modeling and Analysis of Power Processing Systems (MAPPS). Volume 1: Technical report

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    Computer aided design and analysis techniques were applied to power processing equipment. Topics covered include: (1) discrete time domain analysis of switching regulators for performance analysis; (2) design optimization of power converters using augmented Lagrangian penalty function technique; (3) investigation of current-injected multiloop controlled switching regulators; and (4) application of optimization for Navy VSTOL energy power system. The generation of the mathematical models and the development and application of computer aided design techniques to solve the different mathematical models are discussed. Recommendations are made for future work that would enhance the application of the computer aided design techniques for power processing systems

    Karakter Pemimpin Melayu dalam Pemimpin Ungkapan Melayu Karya Tenas Effendy

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    This study discusses the characters in the text Leader Leader Malay Malay phrase Tenas work Effendy. This study used a qualitative approach and descriptive method that aims to describe the characters contained in the text of the Malay phrase Leaders Work Tenas Effendy. In this study the authors used data collection techniques are engineering documentation, then classified based on the character-karakater leader according to Islam formulated into conclusions. The results of the research I have found in this study is the leader according to Islamic code contained in the text leader among Malay expression trustful character, character fathanah, characters and character shidiq sermons

    Molecular mechanisms involved in human platelet aggregation by synergistic interaction of platelet-activating factor and 5-hydroxytryptamine

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    Our recent studies have shown that co-activation of Gq and Gi proteins by 5-hydroxytryptamine (5-HT) and adrenaline show synergism in human platelet aggregation. This study was conducted to examine the mechanism(s) of synergistic interaction of 5-HT and platelet activating factor (PAF) in human platelets. We show that PAF, but not 5-HT, increased platelet aggregation in a concentration-dependent manner. However, low concentrations of 5-HT (2 microM) potentiated platelet aggregation induced by subthreshold concentration of PAF (40 nM) indicating a synergistic interaction between the two agonists and this synergism was blocked by receptor antagonists to either 5-HT or PAF. 5-HT also potentiated the effect of PAF on thromboxane A2 (TXA2) formation and phosphorylation of extracellularly regulated mitogen-activated protein kinases (ERK1/2). The synergism of 5-HT and PAF in platelet aggregation was inhibited by calcium (Ca2+) channel blockers, verapamil and diltiazem, phospholipase C (PLC) inhibitor, U73122, cyclooxygenase (COX) inhibitor, indomethacin, and MEK inhibitor, PD98059. These data suggest that synergistic effect of 5-HT and PAF on human platelet aggregation involves activation of PLC/Ca2+, COX and MAP kinase pathways

    Pemodelan Bidang Gelincir Daerah Payung Batu Menggunakan Metode Resistivitas

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    Tanah longsor merupakan salah satu bencana alam yang umum terjadi di kawasan pegunungan, daerah payung Batu merupakan salah satu daerah rawan longsor. Menurut data kejadian bencana kota Batu tahun 2013 telah tercatat 6 kali tanah longsor di kawasan Payung. Sehingga diperlukan pemodelan bidang gelincir. Letak bidang gelincir diidentifikasi dengan menggunakan metode geolistrik resistivitas. Dalam penelitian ini, pengukuran resistivitas bawah permukaan dilakukan menggunakan konfigurasi wenner. Pengukuran dilakukan pada 2 lintasan berbeda dengan panjang bentangan lintasan 1 sepanjang 120 m dan lintasan 2 sepanjang 100 m. Nilai resistivitas batuan bawah permukaan di daerah penelitian berada pada kisaran harga antara 4,19 Ωm hingga 346 Ωm dengan pendugaan litologi bawah permukaan yang terdiri lempung, tuf pasiran, batu pasir dan breksi konglomerat. Hasil pengolahan data menunjukkan bahwa resistivitas bidang gelincir berada pada kisaran 27,8 Ωm yang diduga berupa lapisan tuff pasiran. Tipe longsoran yang mungkin terjadi yaitu longsoran rotasi
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