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Essential Parameter (essential + parameter)
Selected AbstractsEvaluation of ferromagnetic shape-memory alloys by the extended Hückel methodIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 3 2007Kei Ehara Student Member Abstract Ferromagnetic shape-memory alloy (SMA) are powerful candidates as actuators, pressure sensors, magnetic sensors, etc. Magnetic-field-induced strain has been observed in many ferromagnetic SMA. The magnetic-field-induced strain is a reversible transformation in the martensite phase with the magnetic field. We have investigated the property of the ferromagnetic shape-memory materials by the extended Hückel method, and estimated the ferromagnetic shape-memory of Fe,Pt and Fe,Pd alloys at high temperatures. We used two physical quantities, i.e. cohesive energy and energy fluctuation, to measure the stability of the materials. On the basis of the cohesive energy and energy fluctuation, we discuss the characteristics of ferromagnetic SMA, in which the energy fluctuation is a measure of thermal stability of the metals and/or alloys. The martensite structure is unstable, which means that the energy fluctuation has to be controlled to a small value to keep the martensite phase. Furthermore, it is estimated that the energy fluctuation is associated with the Curie temperature. The Curie temperature is an essential parameter for ferromagnetic materials. From the discussion presented above, we can propose the following: (i) Alloys possessing a low cohesive energy are associated with a high mobility of atoms and are suitable for ferromagnetic shape-memory materials; (ii) Alloys showing a low energy fluctuation show ferromagnetic shape-memory and are favored for use as memory devices. We found that I (iodine) is the best dopant for Fe,Pt ferromagnetic SMA, and Tc (technetium) is the best dopant for Fe,Pd ferromagnetic SMA. Copyright © 2007 Institute of Electrical Engineers of Japan© 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Assessment of tumor oxygenation by electron paramagnetic resonance: principles and applicationsNMR IN BIOMEDICINE, Issue 5 2004Bernard Gallez Abstract This review paper attempts to provide an overview of the principles and techniques that are often termed electron paramagnetic resonance (EPR) oximetry. The paper discusses the potential of such methods and illustrates they have been successfully applied to measure oxygen tension, an essential parameter of the tumor microenvironment. To help the reader understand the motivation for carrying out these measurements, the importance of tumor hypoxia is first discussed: the basic issues of why a tumor is hypoxic, why these hypoxic microenvironments promote processes driving malignant progression and why hypoxia dramatically influences the response of tumors to cytotoxic treatments will be explained. The different methods that have been used to estimate the oxygenation in tumors will be reviewed. To introduce the basics of EPR oximetry, the specificity of in vivo EPR will be discussed by comparing this technique with NMR and MRI. The different types of paramagnetic oxygen sensors will be presented, as well as the methods for recording the information (EPR spectroscopy, EPR imaging, dynamic nuclear polarization). Several applications of EPR for characterizing tumor oxygenation will be illustrated, with a special emphasis on pharmacological interventions that modulate the tumor microenvironment. Finally, the challenges for transposing the method into the clinic will also be discussed. Copyright © 2004 John Wiley & Sons, Ltd. [source] Bestimmung der Tunnelinnenschalendicke mit zerstörungsfreien PrüfverfahrenBETON- UND STAHLBETONBAU, Issue 8 2006Dietmar Mähner Prof. Dr.-Ing. Der vorliegende Beitrag befaßt sich mit dem Einfluß von zerstörungsfreien Prüfmethoden zur Bestimmung der Tunnelinnenschalendicke und der Auswertung eines auf einer Baustelle durchgeführten Untersuchungsprogramms. Die Bandbreite der Untersuchungen bilden dabei an drei Tunnelblöcken unterschiedlich eingesetzte Meßverfahren und ihre jeweilige spezifische Eignung, verschiedene Meßteams sowie unterschiedliche Meßraster, die jeweils vor und nach der Firstspaltverpressung zum Einsatz kamen und analysiert wurden. Als wichtiger Parameter zum Einfluß der Meßqualität ist hierbei die durchzuführende Kalibrierung der Meßgeräte am Einsatzort zu nennen, die die Grundlage der Meßgenauigkeit bildet. Weiterhin konnte die Qualität bzw. der Erfolg der durchgeführten Firstspaltverpressung mittels eines Injektionsgutes in den Messungen nicht zweifelsfrei bestätigt werden und wurde daher zusätzlich durch Kernbohrungen und endoskopische Aufnahmen überprüft. Mit den daraus gewonnen Erkenntnissen werden wesentliche Aspekte und Empfehlungen aufgeführt, die im Umgang mit den zerstörungsfreien Prüfmethoden zur Dickenbestimmung einer Tunnelschale zu beachten sind und in zukünftige Projekte einfließen sollten. Determining the thickness of tunnel internal shell with non-destructive testing methods This report deals with the influence of non-destructive testing methods for determining the thickness of internal tunnel shells and evaluates the results of examinations performed on a construction site. The investigations cover different measurement techniques performed on three tunnel blocks; also analyzed were the specific advantages of these techniques, the employment measurement personnel and different measurement grids used before and after ridge-gap grouting. An essential parameter influencing the measurement accuracy is the calibration needed by the measurement devices at the site of deployment. Because the measurements were not able to unmistakably confirm the quality or success of ridge-gap grouting through injection, these results had to be examined additionally using drill cores and endoscopy. Permitting a crystallization of essential aspects and recommendations as regards the conduction of non-destructive tests for determining the thickness of tunnel shells, the obtained findings are to be incorporated into future projects. [source] The benefit of the retrofitting of a conventional LC system to micro LC: a practical evaluation in the field of bioanalysis with fluorimetric detectionBIOMEDICAL CHROMATOGRAPHY, Issue 5 2003S. Roy Abstract The interests in liquid micro-chromatography (higher column efficiencies, increase in sensitivity) are now well established. The enhancement of fluorimetric response induced by the reduction of the inner diameter of columns (4.6, 3.0, 1.0 and 0.3,mm respectively) coupled with adapted detection cells to control the loss of efficiency (8,µL for the two first columns and 100,nL for the two smaller ones) has been studied in the bioanalytical field, using the plasma determination of native fluorescent antibacterial agents: fluoroquinolones. Ten-fold enhancement of the signal can easily be obtained when substituting a 0.3,mm i.d. column and 100,nL detection cell for a 4.6,mm i.d. column, and 8,µL detection cell. In addition to inner diameter reduction, the detection cell geometry appears to be an essential parameter to obtain the best enhancement of the recorded signal. Hence, the enhancement of signal with micro-chromatography with fluorimetric detection appears to be a compromise between column inner diameter and flow cell volume reduction. Copyright © 2003 John Wiley & Sons, Ltd. [source] Unsupervised classification methods in food sciences: discussion and outlookJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2008Marcin Kozak Abstract This paper reviews three unsupervised multivariate classification methods: principal component analysis, principal component similarity analysis and heuristic cluster analysis. The theoretical basis of each method is presented in brief, and assumptions inherent to the methods are highlighted. A literature review shows that these methods have sometimes been used inappropriately or without referencing all essential parameters. The paper also brings to the attention of the reader a relatively unknown method: probabilistic or model-based cluster analysis. The goal of this method is to uncover the true classification of objects rather than a convenient classification provided by the other methods. For this reason it is felt that model-based cluster analysis will have broad application in the future. Copyright © 2008 Society of Chemical Industry [source] SNPs in the porcine GOT1 gene improve a QTL for serum aspartate aminotransferase activity on SSC14ANIMAL GENETICS, Issue 3 2010G. Reiner Summary Clinical,chemical traits are essential parameters to quantify the health status of individuals and herds, but the knowledge about their genetic architecture is sparse, especially in swine. We have recently described three QTL for serum aspartate aminotransferase activity (sAST), and one of these maps to a region on SSC14 where the aspartate aminotransferase coding gene GOT1 is located. This QTL was only apparent under the acute burden of a model disease. The aim of the present study was to characterize GOT1 as a candidate gene and to test the effects of different GOT1 SNPs as potential quantitative trait nucleotides (QTNs) for sAST. Nine SNPs within GOT1 were identified, and SNP c.-793C>G significantly increased the QTL effects and narrowed the confidence interval from 90 to 15 cM. Additionally, we found a significant association of SNP c.-793C>G in a commercial outbred line, but with reversed phase. We conclude that GOT1 is a putative candidate gene for the sAST QTL on SSC14, and that SNP c.-793C>G is close to the responsible QTN. [source] EFFECT OF BENAZEPRIL ON HEART RATE TURBULENCE IN PATIENTS WITH DILATED CARDIOMYOPATHYCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 7 2007Jiang-Hua Zhong SUMMARY 1Heart rate (HR) turbulence describes short-term sinus rhythmic fluctuation after a single premature ventricular beat. Turbulence onset (TO) and turbulence slope (TS) are two essential parameters in HR turbulence. Turbulence onset and TS have been used to evaluate cardiac autonomic nerve function. 2In the present study, we measured the HR turbulence in dilated cardiomyopathy (DCM) and determined the possible role of benazepril, an angiotensin-converting enzyme inhibitor (ACEI), on these parameters. There were three groups: control, DCM and DCM treated with benazepril. The control group consisted of normal subjects with PVB, but no structural heart disease. Ambulatory electrocardiogram, blood pressure and echocardiography were analysed. 3There was an increase in TO and a decrease in TS in DCM patients. Benazepril treatment (10 mg/day, p.o.) reduced those changes. There were no significant differences in blood pressure and left ventricular ejection fraction (LVEF) between DCM patients and DCM patients treated with benazepril. 4Linear regression analysis showed that TO was negatively correlated with LVEF, whereas TS was positively correlated with LVEF, in the DCM group. After benazepril treatment, the correlations between TO and TS and LVEF disappeared. 5It is concluded that the TO and TS of HR turbulence are altered in patients with DCM. These alterations indicate a dysfunction of the autonomic control of cardiac electrophysiology in DCM patients. Although TO and TS are correlated with LVEF in DCM patients, the effect of benazepril in improving HR turbulence parameters is not a result of its action on heart function, which suggests a new beneficial effect of ACEI in the treatment of DCM patients. [source] | ||||||||||||||||