967 resultados para ANALYZER


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This paper presents a systematic description of the methods for calibrating microwave network analyzer and test fixtures, and discusses the problems arising in the calibration. The general criteria for choosing calibration standards and corresponding algorithms are discussed and suggestions to overcome these problems and improve the calibration accuracy are also given. It has been found that for reciprocal test fixtures, the four equations obtained with the thru standard can be used at the same time. Meanwhile, the calibration accuracy can be improved. It has been shown that using the same calibration procedures but different algorithms may lead to the occurrence of frequency limitation.

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Presently, Queens University Belfast is constructing a unique permanent magnet EBIT which grants unparalleled access to the photons from the trap region. However measurements of ions would still require their transfer through the collector to other measurement areas. To allow more representative sampling, a new in situ analyzer is proposed to be situated immediately at the collector end of the trap region. This analyzer may detect ions by expanding the radius of their cyclotron motion using electric fields until the ions strike Microsphere Plates (MSPs). It may also be possible by using trochoidal motion to detect product electrons. This is important as these have never been detected before in an EBIT. The preliminary design is described in this paper. (c) 2005 Elsevier B.V. All rights reserved.

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Red blood cell (RBC) parameters such as morphology, volume, refractive index, and hemoglobin content are of great importance for diagnostic purposes. Existing approaches require complicated calibration procedures and robust cell perturbation. As a result, reference values for normal RBC differ depending on the method used. We present a way for measuring parameters of intact individual RBCs by using digital holographic microscopy (DHM), a new interferometric and label-free technique with nanometric axial sensitivity. The results are compared with values achieved by conventional techniques for RBC of the same donor and previously published figures. A DHM equipped with a laser diode (lambda = 663 nm) was used to record holograms in an off-axis geometry. Measurements of both RBC refractive indices and volumes were achieved via monitoring the quantitative phase map of RBC by means of a sequential perfusion of two isotonic solutions with different refractive indices obtained by the use of Nycodenz (decoupling procedure). Volume of RBCs labeled by membrane dye Dil was analyzed by confocal microscopy. The mean cell volume (MCV), red blood cell distribution width (RDW), and mean cell hemoglobin concentration (MCHC) were also measured with an impedance volume analyzer. DHM yielded RBC refractive index n = 1.418 +/- 0.012, volume 83 +/- 14 fl, MCH = 29.9 pg, and MCHC 362 +/- 40 g/l. Erythrocyte MCV, MCH, and MCHC achieved by an impedance volume analyzer were 82 fl, 28.6 pg, and 349 g/l, respectively. Confocal microscopy yielded 91 +/- 17 fl for RBC volume. In conclusion, DHM in combination with a decoupling procedure allows measuring noninvasively volume, refractive index, and hemoglobin content of single-living RBCs with a high accuracy.

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UANL

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SMPS and DMS500 analysers were used to measure particulate size distributions in the exhaust of a fully annular aero gas turbine engine at two operating conditions to compare and analyse sources of discrepancy. A number of different dilution ratio values were utilised for the comparative analysis, and a Dekati hot diluter operating at a temperature of 623°K was also utilised to remove volatile PM prior to measurements being made. Additional work focused on observing the effect of varying the sample line temperatures to ascertain the impact. Explanations are offered for most of the trends observed, although a new, repeatable event identified in the range from 417°K to 423°K – where there was a three order of magnitude increase in the nucleation mode of the sample – requires further study.

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Objective To compare results reported for blood gas partial pressures, electrolyte concentrations, and Hct in venous blood samples collected from cattle, horses, and sheep and analyzed by use of a portable clinical analyzer (PCA) and reference analyzer (RA).Animals-Clinically normal animals (24 cattle, 22 horses, and 22 sheep).Procedures-pH; Pco(2); Po(2); total carbon dioxide concentration; oxygen saturation; base excess; concentrations of HCO(3)(-), Na(+), K(+), and ionized calcium; Hct; and hemoglobin concentration were determined with a PCA. Results were compared with those obtained for the same blood sample with an RA. Bias (mean difference) and variability (95% confidence interval) were determined for all data reported. Data were also subjected to analyses by Deming regression and Pearson correlation.Results-Analysis of Bland-Altman plots revealed good agreement between results obtained with the PCA and those obtained with the RA for pH and total carbon dioxide concentration in cattle, K(+) concentration in horses and sheep, and base excess in horses. Except for Na(+) concentration and Hct in horses and sheep, correlation was good or excellent for most variables reported.Conclusions and Clinical Relevance-Data from blood gas and electrolyte analyses obtained by use of the PCA can be used to evaluate the health status of cattle, horses, and sheep. Furthermore, the handheld PCA device may have a great advantage over the RA device as a result of the ability to analyze blood samples on farms that may be located far from urban centers. (Am J Vet Res 2010;71:515-521)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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This paper addresses the problem of processing biological data, such as cardiac beats in the audio and ultrasonic range, and on calculating wavelet coefficients in real time, with the processor clock running at a frequency of present application-specified integrated circuits and field programmable gate array. The parallel filter architecture for discrete wavelet transform (DWT) has been improved, calculating the wavelet coefficients in real time with hardware reduced up to 60%. The new architecture, which also processes inverse DWT, is implemented with the Radix-2 or the Booth-Wallace constant multipliers. One integrated circuit signal analyzer in the ultrasonic range, including series memory register banks, is presented. © 2007 IEEE.

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The Cell-dyn 3500 is a multiparameter flow cytometer, which may analyze samples from several species performing several simultaneous analyses. It is able to perform white blood cells, red blood cells and platelet counts, besides differential leukocyte counts, packed cell volume and hemoglobin determination. Cell-Dyn 3500 performs total leukocyte count both optically and by impedance. The equipment may choose one or other method, based on the reliability of the results. Erythrocyte and platelet counts are determined by impedance. Leukocyte differentiation is based on an optical principle, using separation in multiangular polarized light. The objective of this study was to compare the results of complete blood count of Zebu Nellore heifers from Cell-dyn 3500, with those obtained from a semi-automated cell counter (Celm CC 510) and the manual technique. Blood samples were collected from the jugular vein in 5 mL EDTA vacuum tubes from 58 Nellore heifers, at 24 months of age. Samples were processed in parallel in the three different techniques. Results were analyzed using paired t test, Pearson's correlation and the Bland-Altmann method. There was a strong correlation for all parameters analyzed by Cell-Dyn 3500, manual method and semi-automated cell counter, except for basophils and monocytes counts. These results confirm that this analyzer is reliable for blood samples analysis of zebu cattle.