6,388 research outputs found
Immunogenicity of Haemophilus influenzae b conjugate vaccine (HibTITER) and safety of HibTITER and a combination vaccine of diphtheria, tetanus, pertussis and HibTITER in infants two months of age: a preliminary report.
No full textAssessing avian point-count duration and sample size using species accumulation functions.
No full textNeon Soft X-Ray Yield Optimization from PF-SY1 Plasma Focus Device
No full textBased on the consideration of that for operation of the plasma focus in neon, a focus pinch compression temperature of 200–500 eV (2.3 × 106–5 × 106 K) is suitable for good yield of neon soft X-rays (SXR), numerical experiments have been investigated on the plasma focus device PF-SY1 using the latest version Lee model code. The Lee model code is firstly applied to characterize the PF-SY1 Plasma Focus. Keeping the bank parameters and operational voltage unchanged but systematically changing other parameters, numerical experiments were performed finding the optimum Y sxr was 0.026 J. Thus we expect to increase the neon Y sxr of PF-SY1 from its present typical operation; without changing the capacitor bank and the electrode configuration merely by changing the operating pressure. The Lee model code was also used to run numerical experiments on PF-SY1 with neon gas for optimizing soft X-ray yield with reducing L 0, varying z 0 and ‘a’. From these numerical experiments we expect to increase the neon Y sxr of PF-SY1 with reducing L 0, from the present 0.026 J at L 0 = 1600 nH to maximum value of near 26 J at an achievable L 0 = 10 nH
Spotlight counts of giant flying squirrels (Petaurista-petaurista and P-alborufus) in Taiwan.
No full textBird species richness patterns of northern Taiwan: primary productivity, human population density, and habitat heterogeneity.
No full textA population study of house mice(Mus musculus castaneus) inhabiting rice granaries in Taiwan
No full textExperimental and numerical fitting of model parameters versus the gas pressure using six phase radiative Lee model in AECS PF‐1, 2 and INTI PF for nitrogen, argon, and neon gases
No full textAtomic energy commission of syria (AECS) PF‐1, 2 devices were operated in N2 and Ar gases at pressures varied between 0.1–1 mbar and applied voltage of 15 kV on the capacitors bank with capacitance of 25 μF. The voltage, current, and current derivative curves were digitally recorded by Ohmic voltage divider and two Rogowskii coils; one with a big number of turns for current and the other one with a low number of turns for the current derivative. Also, the current curve for the discharge as LCR circuit was recorded to calibrate the current measurement. By integrating the current derivative in time and using the curve of calibrated current, the current curve free of noise has been established. By inserting the geometrical and electrical parameters of two AECS PF‐1, 2 devices, the working gas pressure and the kind of the gas into six phase model which describes the instability in the plasma, and adding the anomalous resistance as a term in the current and voltage equations in the model; the computed curves for voltage and current were found and compared with the obtained experimental curves at the same conditions taking into account the readjustment of model parameters fm, fc, fmr, and fcr until getting a good fitting between the measured and computed currents. This fitting has proved the validity of six phase Lee model and its ability to give a description of plasma focus in the radial phase stage (which consists now of four subradial phases: radial inward shock, radial reflected shock, the pinch phase, and after that the instability phase), which is followed by the expanded phase of plasma focus. In parallel to our work, similar efforts were made on the INTI PF device in Ne; the validity of six phase Lee model was proved by getting a proper fitting between the measured and computed currents under the operational conditions. Moreover, the equivalent resistances and time scales of the anomalous resistance phases were obtained by this method; also, the ratios for PF device classification into two types according to the static inductance of the PF system were determined for N2 and Ar as working gases in AECS‐PF1, 2
Practical Optimization of AECS PF-2 Plasma Focus Device for Argon Soft X-ray Operation
No full textFor operation of the plasma focus in argon, a focus pinch compression temperature range of 1.4–5 keV (16.3 × 106–58.14 × 106 K) is found to be suitable for good yield of argon soft X-rays (SXR) Ysxr. This is based on reported temperature measurements of argon plasmas working at regime for X-ray output. Using this temperature window, numerical experiments have been investigated on AECS PF-2 plasma focus device with argon filling gas. The model was applied to characterize the 2.8 kJ plasma focus AECS PF-2. The optimum Ysxr was found to be 0.0035 J. Thus, we expect to increase the argon Ysxr of AECS PF-2, without changing the capacitor bank, merely by changing the electrode configuration and operating pressure. The Lee model code was also used to run numerical experiments on AECS PF-2 with argon gas for optimizing soft X-ray yield with reducing L0, varying z0 and ‘a’. From these numerical experiments we expect to increase the argon Ysxr of AECS PF-2 with reducing L0, from the present computed 0.0035 J at L0 = 270 nH to maximum value of near 0.082 J, with the corresponding efficiency is about 0.03%, at an achievable L0 = 10 nH
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