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Probe Design (probe + design)
Selected AbstractsUse of mutually inductive coupling in probe design,CONCEPTS IN MAGNETIC RESONANCE, Issue 4 2002D.I. Hoult Abstract An analysis is presented of mutually inductive coupling in probe design. It is assumed that near field couplings predominate and that lumped constants may therefore be employed. Using three published designs as examples, analytic techniques are presented for assessing B1 field strength, losses, and signal-to-noise ratio in increasingly complex situations. The perturbing effect of the B1 field from a matching coil is examined and it is shown that if the coil is too close to the sample there can be an asymmetry introduced in the rotating frame B1 field. It is then shown that such asymmetries are potentially a general feature of inductively coupled, loaded coils. The importance of suppressing unwanted resonances is highlighted if tuning and matching are to be orthogonal, a potential advantage of mutually inductive matching. Finally, a lumped-constant simulation is briefly described for those situations where an analytic approach becomes too cumbersome. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 262,285, 2002 [source] Comparative Study of Flat and Round Collectors Using a Validated 1D Fluid Probe ModelCONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2006P. Peleman Abstract In the literature two different types of Gundestrup-like probe designs are proposed: design with flat and with round collectors. In this paper we study the influence of different collector shapes of Gundestrup-like probes on the accuracy of the measurement of the parallel and perpendicular flows. A one dimensional fluid probe model is used for deducing both Mach numbers of the unperturbed flow from the probe data. An analytical expression relates the plasma flow to the measured ion saturation currents collected at the upstream and downstream collecting surfaces of the probe. For flat collectors, the analytical model is validated by comparing it to a two dimensional quasi-neutral Particle In Cell (PIC) simulation code. An extension of the theoretical model then allows us to study round collectors. We performed an accuracy study which showed that systematic errors are introduced when round collectors are employed for determination of the perpendicular flow which is systematically overestimated. The error can reach more than 70% when the perpendicular flow increases and when the angle of the collecting surface with respect to the magnetic field (, , 0)is small. The correct analytical expression is applied to experimental data from Gundestrup probe measurements with round collectors on the CASTOR tokamak. The analysis shows that for these measurements the error introduced by using the expression for flat collectors remains negligible, supporting our former use of the model for flat collectors. A new advanced Gundestrup-like probe design and the motivation for the choice of flat collectors are presented. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] New Developments of Self-emitting Electrostatic Probes for use in High Temperature PlasmasCONTRIBUTIONS TO PLASMA PHYSICS, Issue 7-8 2004M. A. Fink Abstract Emissive electrostatic probes for the use in fusion experiments must be able to sustain significantly higher thermal loads than in low-temperature plasma experiments. Several types of probe design are discussed, the results from the use of such probes in the edge plasma of the Wendelstein 7-AS stellarator are presented and compared with the predictions of emissive and non-emissive probe models. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Factors associated with development of stroke long-term after myocardial infarction: experiences from the LoWASA trialJOURNAL OF INTERNAL MEDICINE, Issue 2 2005J. HERLITZ Abstract. Objective., To describe factors associated with the development of stroke during long-term follow-up after acute myocardial infarction (AMI) in the LoWASA trial. Patients., Patients who had been hospitalized for AMI were randomized within 42 days to receive either warfarin 1.25 mg plus aspirin 75 mg daily or aspirin 75 mg alone. Design., The study was performed according to the probe design, that is open treatment and blinded end-point evaluation. Setting., The study was performed in 31 hospitals in Sweden. The mean follow-up time was 5.0 years with a range of 1.7,6.7 years. Results., In all, 3300 patients were randomized in the trial, of which 194 (5.9%) developed stroke (4.2% nonhaemorrhagic, 0.5% haemorrhagic and 1.3% uncertain. The following factors appeared as independent predictors for an increased risk of stroke: age, hazard ratio and 95% confidence interval (1.07; 1.05,1.08), a history of diabetes mellitus (2.4; 1.8,3.4), a history of stroke (2.3; 1.5,3.5), a history of hypertension (2.0; 1.5,2.7) and a history of smoking (1.5;1.1,2.0). Most of these factors were also predictors of a nonhaemorrhagic stroke whereas no predictor of haemorrhagic stroke was found. Conclusion., Risk indicators for stroke long-term after AMI were increasing age, a history of either diabetes mellitus, stroke, hypertension or smoking. [source] The Effectiveness of a Color-Coded, Onset-Rime Decoding Intervention with First-Grade Students at Serious Risk for Reading DisabilitiesLEARNING DISABILITIES RESEARCH & PRACTICE, Issue 1 2009Sara J. HinesArticle first published online: 3 FEB 200 This study was an investigation into the effectiveness of a color-coded, onset-rime,based decoding intervention with first-graders at serious risk for reading disabilities using a single-subject multiple probe design. Students increased their ability to decode instructional words on average 73% over baseline. For novel words from instructed rime patterns, scores increased by an average of 56%. Transfer at the vowel level to uninstructed rime patterns was limited, with scores improving by an average of 29%. Students maintained decoding gains at 1-week and 1-month maintenance. While acknowledging the difficulty in predicting reading disabilities based on first-grade performance, the effectiveness of the early intervention is a promising step in finding an instructional approach that is successful with the most at risk or disabled students who often do not respond to effective remedial programs. [source] A Ratiometric Fluorescent Probe for Hypochlorite Based on a Deoximation ReactionCHEMISTRY - A EUROPEAN JOURNAL, Issue 10 2009Weiying Lin Prof. Abstract The first ratiometric fluorescent probe for hypochlorite has been developed through regulation of the electron-withdrawing ability of the electron acceptor in an intramolecular charge-transfer (ICT) system by a deoximation reaction (see figure; EWG=electron-withdrawing group). In this work, we have successfully provided a novel strategy for the rational design and synthesis of a ratiometric fluorescent probe for hypochlorite. The strategy is based on the deoximation reaction, which has not yet been used in the fluorescent hypochlorite probe design. Interestingly, the probe showed a ratiometric fluorescent response to hypochlorite with the emission intensities ratio (I509/I439) increasing from 0.28 to 2.74. Furthermore, the probe displayed high selectivity for hypochlorite over other species due to the distinct deoximation conditions. The probe developed herein represents the first ratiometric fluorescent probe for hypochlorite. [source] Comparative Study of Flat and Round Collectors Using a Validated 1D Fluid Probe ModelCONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2006P. Peleman Abstract In the literature two different types of Gundestrup-like probe designs are proposed: design with flat and with round collectors. In this paper we study the influence of different collector shapes of Gundestrup-like probes on the accuracy of the measurement of the parallel and perpendicular flows. A one dimensional fluid probe model is used for deducing both Mach numbers of the unperturbed flow from the probe data. An analytical expression relates the plasma flow to the measured ion saturation currents collected at the upstream and downstream collecting surfaces of the probe. For flat collectors, the analytical model is validated by comparing it to a two dimensional quasi-neutral Particle In Cell (PIC) simulation code. An extension of the theoretical model then allows us to study round collectors. We performed an accuracy study which showed that systematic errors are introduced when round collectors are employed for determination of the perpendicular flow which is systematically overestimated. The error can reach more than 70% when the perpendicular flow increases and when the angle of the collecting surface with respect to the magnetic field (, , 0)is small. The correct analytical expression is applied to experimental data from Gundestrup probe measurements with round collectors on the CASTOR tokamak. The analysis shows that for these measurements the error introduced by using the expression for flat collectors remains negligible, supporting our former use of the model for flat collectors. A new advanced Gundestrup-like probe design and the motivation for the choice of flat collectors are presented. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Development of a minimally invasive epidermal abrasion device for clinical skin sampling and its applications in molecular biologyINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 1 2009J.-M. Lee Synopsis A new abrasion tool (US patent US7087063 B2) has been developed for collecting skin epidermal samples. This device includes a central shaft that holds the probe in a split chuck. Of the variety of probe designs tested, the laser-cut hollow tube (HT) probe abraded the basal layer of the epidermis most consistently, resulting in representative epidermal skin samples. Compared with traditional clinical methods, the abrasion method allows for high-throughput epidermal skin collection with minimal invasiveness to the volunteer subjects. A large number of abrasion samples have been collected in various clinical studies with no adverse effects observed. Epidermal abrasion, when used appropriately and with the optimized probes, can yield high quality tissue samples that are representative of the epidermis. A sufficient quantity of RNA and protein can be obtained for many subsequent molecular and biochemical applications. Because of its minimal invasiveness and high-throughput nature, the abrasion method can be a valuable tool used to investigate the efficacy of topical applications of skin care products. Resume Un nouvel outil d'abrasion (US Patent US 7 087 063 B2) a été développé pour collecter des échantillons de peaux épidermiques. Cet instrument est constitué d'une tige centrale qui tient la sonde dans un mandrin fendu. Parmi tous les modèles de sondes testées, celle constituée d'un tube creux (HT) coupé au laser, abrase la couche basale de l'épiderme le plus régulièrement, conduisant ainsi à des échantillons de peaux épidermiques représentatifs. Comparée aux méthodes classiques, la méthode d'abrasion permet un prélèvement de peaux épidermiques haut débit avec un minimum d'invasion des sujets volontaires. Un grand nombre d'échantillons a été collecté dans diverses études cliniques sans qu'aucun effet adverse n'ait été observé. L'abrasion épidermique, quand elle est utilisée de façon appropriée et avec une sonde appropriée, peut conduire à des échantillons de haute qualité qui sont représentatifs de l'épiderme. Une quantité suffisante d'ARN et de protéines peut être obtenue en vue de tests moléculaires et biochimiques. Du fait de sa faible agressivité et de sa nature haut débit, la méthode d'abrasion peut être un outil précieux utilisé pour étudier l'efficacité des applications topiques de produits de soins cutanés. [source] | ||||||||||