612 research outputs found

    Training and recovery behaviours of exchange bias in FeNi/Cu/Co/FeMn spin valves at high field sweep rates

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    Training and recovery of exchange bias in FeNi/Cu/Co/FeMn spin valves have been studied by magnetoresistance curves with field sweep rates from 1000 to 4800 Oe/s. It is found that training and recovery of exchange field are proportional to the logarithm of the training cycles and recovery time, respectively. These behaviours are explained within the model based on thermal activation. For the field sweep rates of 1000, 2000 and 4000 Oe/s, the relaxation time of antiferromagnet spins are 61.4, 27.6, and 11.5 in the unit of msms respectively, much shorter than the long relaxation time (~10^2 s) in conventional magnetometry measurements.Comment: 10pages, 3 figure

    Laser-driven plasma waves in capillary tubes

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    The excitation of plasma waves over a length of up to 8 centimeters is, for the first time, demon- strated using laser guiding of intense laser pulses through hydrogen filled glass capillary tubes. The plasma waves are diagnosed by spectral analysis of the transmitted laser radiation. The dependence of the spectral redshift, measured as a function of filling pressure, capillary tube length and incident laser energy, is in excellent agreement with simulation results. The longitudinal accelerating field inferred from the simulations is in the range 1 -10 GV/m

    Subcutaneous Immunoglobulin Replacement Therapy with Hizentra® is Safe and Effective in Children Less Than 5 Years of Age.

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    BACKGROUND:Hizentra® (IGSC 20%) is a 20% liquid IgG product approved for subcutaneous administration in adults and children 2 years of age and older who have primary immunodeficiency disease (PIDD). There is limited information about the use of IGSC 20 % in very young children including those less than 5 years of age. METHODS:A retrospective chart review involved 88 PIDD infants and children less than 5 years of age who received Hizentra®. RESULTS:The mean age at the start of Hizentra® was 34 months (range 2 to 59 months). IGSC 20 % was administered weekly to 86 infants (two additional infants received twice weekly and three times weekly infusions, respectively) and included an average of 63 infusions (range 6-182) for an observation period up to 45.5 months. Infusion by manual delivery occurred in 15 patients. The mean dose was 674 mg/kg/4 weeks. The mean IgG level was 942 mg/dL while on IGSC 20 %, compared to a mean trough IgG level of 794 mg/dL (p < 0.0001) during intravenous or subcutaneous IgG administration prior to IGSC 20 %. Average infusion time was 47 (range 5-120) minutes, and the median number of infusion sites was 2 (range 1-4). Local reactions were mostly mild and observed in 36/88 (41%) children. No serious adverse events were reported. A significant increase in weight percentile (7 % ± 19.2, p = 0.0012) among subjects was observed during IGSC 20% administration. The rate of serious bacterial infections was 0.067 per patient-year while receiving IGSC 20%, similar to previously reported efficacy studies. CONCLUSIONS:Hizentra® is effective in preventing infections, and is well tolerated in children less than age 5 years

    Effects of laser prepulses on laser-induced proton generation

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    Low-intensity laser prepulses (<10(13) W cm(-2), nanosecond duration) are a major issue in experiments on laser-induced generation of protons, often limiting the performances of proton sources produced by high-intensity lasers (approximate to 10(19) W cm(-2), picosecond or femtosecond duration). Depending on the intensity regime, several effects may be associated with the prepulse, some of which are discussed in this paper: (i) destruction of thin foil targets by the shock generated by the laser prepulse; (ii) creation of preplasma on the target front side affecting laser absorption; (iii) deformation of the target rear side; and (iv) whole displacement of thin foil targets affecting the focusing condition. In particular, we show that under oblique high-intensity irradiation and for low prepulse intensities, the proton beam is directed away from the target normal. Deviation is towards the laser forward direction, with an angle that increases with the level and duration of the ASE pedestal. Also, for a given laser pulse, the beam deviation increases with proton energy. The observations are discussed in terms of target normal sheath acceleration, in combination with a laser-controllable shock wave locally deforming the target surface

    Relativistic nature of a magnetoelectric modulus of Cr_2O_3-crystals: a new 4-dimensional pseudoscalar and its measurement

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    Earlier, the magnetoelectric effect of chromium sesquioxide Cr_2O_3 has been determined experimentally as a function of temperature. One measures the electric field-induced magnetization on Cr_2O_3 crystals or the magnetic field-induced polarization. From the magnetoelectric moduli of Cr_2O_3 we extract a 4-dimensional relativistic invariant pseudoscalar α~\widetilde{\alpha}. It is temperature dependent and of the order of 10^{-4}/Z_0, with Z_0 as vacuum impedance. We show that the new pseudoscalar is odd under parity transformation and odd under time inversion. Moreover, α~\widetilde{\alpha} is for Cr_2O_3 what Tellegen's gyrator is for two port theory, the axion field for axion electrodynamics, and the PEMC (perfect electromagnetic conductor) for electrical engineering.Comment: Revtex, 36 pages, 9 figures (submitted in low resolution, better quality figures are available from the authors

    Geohazards analysis of Pisa tunnel in a fractured incompetent rocks in Zagros Mountains, Iran.

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    The Pisa 2 tunnel with 740 m in length and 20° N trend is located along the Kazerun fault zone in Simply Folded Belt of Zagros, Iran. This tunnel has been excavated in the fractured incompetent marl layers with high expansive pressure of up to 2 kg/cm2. In this study, the geological hazards along the tunnel have been recognized and categorized. This study revealed that, in the long-term usage of the tunnel, the lining did not endure against the loading and the secondary leakages. It is mainly attributed due to the non-efficiencies of drainage and isolation systems in the tunnel site. Therefore, it caused asphalt damage, drainage damage, and wall distortion. FLAC3D software has been used in this research. We conducted various analyses for pre-excavation stress states, syn-excavation, and post-excavation strain states. The results showed no indication of instability and critical deformations during the excavation time. It also revealed that due to the non-efficiencies of drainage and isolation systems against secondary leakages and consequently marl expansion, the volumetric and shear strains (i.e., expansions and displacements) have exceeded from the critical states of strain along the tunnel. For various remedy purpose, this paper attempted several measures that can be taken in order to modify the drainage and isolation systems along the tunnel area. The reconstruction of drainage systems with suitable reinforced concrete and adequate slope has been proposed. The width of channel and isolation of backside of lining and implementation of multi-order outlets (i.e., backside of lining) for draining of groundwater into where the main drainage systems are located in the tunnel gallery were suggested

    Simple and Complex Diets for Early Weaned Pigs

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    During recent years many swine producers have adopted the practice of weaning pigs between 21 and 28 days of age. This allows for a shorter interval between farrowings, resulting in more litters per sow per year. Most research has indicated early weaned pigs perform better when fed complex diets containing some milk product, sugar, fat, oats or other ingredients compared to simple corn-soybean meal fortified diets. However, the economics of cost of feed per unit of gain has often favored the simple diets. The objective of this experiment was to evaluate pig starter diets equalized in lysine content but varying in protein content and source of ingredients when fed to pigs of approximately 28 days of age

    Effect of Virginiamycin on Growth and Carcass Characteristics of Barrows and Gilts

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    Antibiotics have been used as additives to swine diets for approximately 30 years. Various antibiotics have been shown to improve growth performance and efficiency of feed utilization. In addition, antibiotics have reduced low order infection. Since different organisms are sensitive to different antibiotics, the antibiotic of choice may vary depending on the organisms present. The effect of antibiotics on carcass characteristics has been less conclusive. This experiment was conducted to determine the effect of the antibiotic, virginiamycin, on performance and carcass characteristics of barrows and gilts fed separately

    The Effects of One Day Flushing and Early Gestation Energy Levels on Reproductive Performance of Gilts

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    The experiment reported here was conducted to determine what effect one-feed flushing and energy level during the first third of gestation had on reproductive performance

    The Effect of Pen Space and Vitamin C Addition to the Diet on Weanling Pig Performance

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    It is assumed that there is no dietary requirement for vitamin C by the pig. However, recently there has been some indication that, under certain conditions, vitamin C or ascorbic acid may boost pig performance. Vitamin C is involved in development of the immune response. Therefore, if a requirement for dietary vitamin C exists, it should be demonstrated with pigs under stressed conditions. The study reported in this paper is a part of a cooperative project by the NCR-89 Committee on Confinement Management of Swine. It is designed to evaluate the response of weaned pigs to a vitamin C addition to the diet when placed under the stress of reduced pen space and feeder space
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