3,607 research outputs found

    Spin torque ferromagnetic resonance with magnetic field modulation

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    We demonstrate a technique of broadband spin torque ferromagnetic resonance (ST-FMR) with magnetic field modulation for measurements of spin wave properties in magnetic nanostructures. This technique gives great improvement in sensitivity over the conventional ST-FMR measurements, and application of this technique to nanoscale magnetic tunnel junctions (MTJs) reveals a rich spectrum of standing spin wave eigenmodes. Comparison of the ST-FMR measurements with micromagnetic simulations of the spin wave spectrum allows us to explain the character of low-frequency magnetic excitations in nanoscale MTJs.Comment: Also see: http://faculty.sites.uci.edu/krivorotovgroup

    Osseous sarcoidosis

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    Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas

    Vulvar Tuberculosis-A Rare Manifestation of the Disease

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    Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis. According to data from the World Health Organization, this disease remains one of the leading causes of death worldwide. Although it most commonly affects the lungs, tuberculosis can compromise any organ. The present study reports a rare case of vulvar tuberculosis in a postmenopausal woman with a history of asymptomatic pulmonary and pleural tuberculosis, with no prior documented contact with the bacillus. Diagnosis was based on vulvar lesion biopsies, with histological findings suggestive of infection and isolation of M. tuberculosis by microbiological culture and polymerase chain reaction (PCR) essays. The lesions reverted to normal after tuberculostatic therapy.info:eu-repo/semantics/publishedVersio

    Stacking effect via solvent polarity differences in micellar electrokinetic chromatography with aqueous-organic background electrolyte

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    In this manuscript, a new stacking mode for micellar electrokinetic chromatography with anionic micelles and neutral analytes was investigated. The variation in the velocity of the analytes between the sample and the separation zones, needed for stacking effects, was obtained by using solvents with different polarities, the concentration of salts and micelles being identical between the two zones. Whereas a pure aqueous solvent was used in the injection zone, up to 30% ACN was used in the separation zone. In such conditions, higher interactions between the analyte and the micelles are obtained in the sample zone than in the separation zone, this due to the presence of the organic solvent. As the velocity of neutral analyte depends on its interactions with the moving micelles, its speed will drop when crossing two distinct zones where in the second zone its interactions with the micelles are lower than in the outgoing zone. This will induce a stacking effect. This approach was validated using a background electrolyte in the separation zone made with 10 mM disodium hydrogen phosphate, 15 mM sodium dodecyl sulphate and 15% ACN. The three triazines (simazine, atrazine, and terbuthylazine), used as test analytes, were dissolved in 10 mM disodium hydrogen phosphate, 15 mM sodium dodecyl sulphate and either 15 or 0% ACN. A stacking factor of around 2 was obtained injecting the sample in 0% ACN rather than 15% ACN. This was in accordance with the theoretical values predicted measuring the effective mobilities in both zonesCOMPETE/QREN/UE and PTDC/QUI-QUI/116156/2009 and SFRH / BPD / 30548 / 200

    Cerenkov angle and charge reconstruction with the RICH detector of the AMS experiment

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    The Alpha Magnetic Spectrometer (AMS) experiment to be installed on the International Space Station (ISS) will be equipped with a proximity focusing Ring Imaging Cerenkov (RICH) detector, for measurements of particle electric charge and velocity. In this note, two possible methods for reconstructing the Cerenkov angle and the electric charge with the RICH, are discussed. A Likelihood method for the Cerenkov angle reconstruction was applied leading to a velocity determination for protons with a resolution of around 0.1%. The existence of a large fraction of background photons which can vary from event to event, implied a charge reconstruction method based on an overall efficiency estimation on an event-by-event basis.Comment: Proceedings submitted to RICH 2002 (Pylos-Greece

    Effect of a nuclear polyhedrosis virus on Spodoptera frugiperda (Smith) (Lepidoptera:noctuidae) larvae, its damage and yield of maize crop.

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    The efficiency of Baculovirus in a wettable powder formulation to control the fall armyworm Spodoptera frugiperda (Smith) was evaluated using variations of the recommended dose of 50 grams per hectare (2.5 x 1011 polyhedron inclusion bodies - PIB ha-1): 50 or 100 g ha-1 applied once, and variations of two applications at seven-day intervals, of 25+25, 25 + 50, 50+25 and 50+50 g ha-1, compared to untreated plots. The treatments were arranged in a randomized complete block design with six replications. Each plant at 6-8 or 8-10-leaf growth stages, was artificially infested with 10 newly hatched larvae. The virus suspension (300 L ha-1) was applied 24 hours after larvae infestation using a back-pack-manual sprayer at 40 PSI (2.8 kg cm-2) and a regular flat fan nozzle. Larval mortality rate obtained from plots with the application of 50 g of Baculovirus wettable formulation ha-1, at once (96.2%), was significantly higher than that obtained with the application of 25+25 g ha-1 (85.3%) or 25 + 50 g ha-1 (87.8%). However, it was lower than that obtained from the other virus treatments, which had no significant difference among them (mean of 99.2%). The damage caused by S. frugiperda on the leaves of plants of untreated plots (average of 4.5 in an visual scale from 1 to 5) was significantly different from that observed in plots sprayed with virus (1.75 to 2.33). Plants protected with the virus produced significantly higher yield (mean of 7,577 kg ha-1) than plants unprotected (6,140 kg ha-1), that is, 23.4% higher

    High-risk pulmonary embolism with right heart thrombi

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    Accuracy is essential to surface quality control when a range sensor is applied to measure the 3D shape of an automotive body part. A sensor's viewing pose, including location and orientation, is related to measurement accuracy. It is usually difficult to find an optimal solution by manual control of sensor viewpoints. A CAD-guided robot view planner developed previously can automatically generate viewpoints. Measurement accuracy can be satisfied in a certain range. However, the unpredictable image noises, especially in regions with low intensity contrast, cannot be compensated by the CADguided robot view planner. In another aspect, measurement accuracy is evaluated all over the part surface. The local accuracy of a small patch may exceed the measurement tolerance. In this paper, feedback design is applied to the CADguided robot sensor planning system. The feedback controller can evaluate the accuracy of obtained point clouds, identify problem regions, and generate new viewpoints. This process is recursively executed until the measurement accuracy reaches to a tolerant value. This feedback-based inspection system had been implemented in previous work to fill holes of a point cloud, which are caused by shadows and light reflections. In this paper, the feedback controller is specifically designed to improve the measurement accuracy. Experimental results show the success of applying this feedback system for dimensional inspection of an automotive body part. © 2007 IEEE.Link_to_subscribed_fulltex
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