1,113 research outputs found
Cell architecture upswing based on catalyst coated membrane (CCM) for vanadium flow battery
No full textTo promote the practical application of electro-catalyst in vanadium flow battery, cell architecture based on catalyst coated membrane (CCM) is designed. CCM is prepared via spraying electro-catalyst tungsten trioxide/super activated carbon, which exhibits excellent electrochemical performance toward vanadium redox couples, on both sides of the membrane. Results show that the use of CCM structure reduces the charge transfer impedance of the cell, and thus improves the energy efficiency and the power density remarkably. The voltage efficiency and energy efficiency reach as high as 85.9% and 81.2%, respectively, much higher than that using the traditional cell structure (81.3% and 76.9%) at 120 mA cm(-2). No loss in efficiency after 300 cycles indicates the favorable cycle stability of CCM. Therefore, CCM can be used as a promising vanadium flow battery structure for enhanced efficiency and power density. (C) 2013 Elsevier B.V. All rights reserved
Caractérisation de l'impact rénal à court et long terme du choc hémorragique expérimental murin
No full textLa présence d'une insuffisance rénale aiguë (IRA) est un marqueur indépendant de surmortalité dans de nombreuses pathologies médico-chirurgicales. La première cause d'IRA organique est la nécrose tubulaire aiguë ischémique (NTAI). L'absence d'efficacité, chez l'Homme, des thérapeutiques pourtant testées avec succès chez l'animal pourrait être liée aux carences des modèles expérimentaux de nécrose tubulaire. En effet, ces modèles (clampage artère rénale, dose massive de drogues tubulo-toxiques) proposent une approche caricaturale de l'IRA qui prévient tout mécanisme physiologique d'adaptation. Notre objectif était d'élaborer un nouveau modèle d'IRA par choc hémorragique à pression contrôlée chez la souris C57/Bl6 et d'en étudier les conséquences rénales. Nous avons dans un premier temps mis au point le modèle de choc hémorragique et montré qu'une durée de choc de deux heures à 35 mmHg de pression artérielle moyenne est susceptible de créer une IRA par NTAI. Nous avons dans un deuxième temps étudié les répercussions rénales de ce choc et ainsi observé un impact fonctionnel moléculaire et structurel prédominant entre le 2ème jour (J) et J6 en post choc mais persistant à J21 avec la mise en évidence d'une fibrose rénale et d'anomalies fonctionnelles physiologiques tubulaires rénales. L'existence d'une hypoxie rénale dans les suites du choc nous a amené à étudier son impact dans une population de souris diabétiques de type 2 obèse (db/db). Nous avons en effet confirmé que les reins de souris diabétiques présentaient une hypoxie avant toute agression et que le choc hémorragique aboutissait à un impact fonctionnel plus sévère et une réponse à l'hypoxie différente chez les souris diabétiques. Enfin, la difficulté d'évaluation de la fonction de filtration rénale chez le muridé nous a conduits à effectuer une étude de corrélation entre les marqueurs historiques (créatininémie, urée plasmatique), la cystatine C et le gold standard (la clearance de l'inuline plasmatique) chez 80 souris. Dans cette note technique située en annexe, nous avons pu confirmer que ni l'urée ni la créatininémie par la technique colorimétrique n'étaient des marqueurs fiables chez la souris. La créatininémie par la technique immunoenzymatique et surtout la cystatine c sont mieux corrélées au DFG évalué par la clearance de l'inuline. Au total nous avons décrit un nouveau modèle d'agression rénale chez des souris sauvages C57/Bl6 et une population de souris diabétiques de type 2. Nous avons également mis en évidence l'intérêt de la cystatine C chez la souris en tant que marqueur d'estimation du DFG a contrario des marqueurs historiques (créatininémie par la technique colorimétrique et urée plasmatique).Acute renal failure (ARF) is an independent mortality marker in numerous medical or surgical pathologies. The leading cause of organic ARF is ischemic acute tubular necrosis. The lack of efficacy in humans of therapeutic yet successfully tested in animals may be related to the deficiencies in experimental models of tubular necrosis. Indeed, these models (renal artery clamping, massive dose of tubulo-toxic drugs) propose a caricatural mechanism of ARF and prevent any physiological mechanism of adaptation. Our goal was to develop, in mice, a new model of ARF induced by pressure controlled hemorrhagic shock and to decipher its kidney impact. We initially developed the model of hemorrhagic shock and showed that two hours shock duration at 35 mmHg of mean arterial pressure is likely to create an organic ARF. Then, we tested the impact of this shock on kidney and observed a molecular and functional impact predominant between day (D) 2 and D6 after shock but still present at D21 with renal fibrosis and renal tubular dysfunction. The existence of renal hypoxia in the aftermath of shock led us to study its impact in a population of obese type 2 diabetic mice (db/db). We have indeed confirmed that diabetic mice kidneys already exhibit hypoxia before any aggression and that hemorrhagic shock led to a more severe functional impact and a different response to hypoxia in diabetic mice. At least, because evaluating glomerular filtration (GFR) in mice is hazardous, we have performed a correlation study between the historical markers (serum creatinin, plasma urea), cystatin c and measured GFR. We have confirmed that neither urea nor creatinin obtained by the colorimetric technique are reliable markers in mice. Nevertheless, creatinin obtained by immuno colorimetric assay and particularly cystatin C are better correlated with measured GFR. Altogether, we have described a new model of ARF in two different mice populations: control C57/Bl6 and type 2 diabetic obese mice. We also highlight that cystatin C in mice is more accurate for estimating GFR that historical markers (serum creatinin by the colorimetric technique and plasma urea)
Thermal, mechanical, and morphological properties of novolac-type phenolic resin blended with fullerenol polyurethane and linear polyurethane
No full textPreparation and characterization of fullerene-derived polymer blended with novolac type phenolic resin
No full textFinal report of CCM key comparison of mass standards CCM.M-K6, 50 kg
No full textIn order to show equivalence in mass standards calibration among National Metrology Institutes of member countries of the 'Comité international des poids et mesures' (CIPM), key comparisons of mass standards have been carried out under the auspices of the 'Comité Consultatif pour la Masse et les Grandeurs Apparentées' (CCM).
This key comparison on 50 kg standards in standard stainless steel was based on the decision of the CCM during the 11th meeting held in April 2008 at the 'Bureau International des Poids et Mesures' (BIPM).
For this key comparison CENAM—Mexico acted as pilot laboratory, and NPL—United Kingdom accepted to be co-pilot laboratory.
The aims of this key comparison were to compare the results obtained by NMIs in calibration of 50 kg stainless steel weights and to repeat the exercise realized in 2001–2002 with the key comparison identified as CCM.M-K3
Pou Mang Ma, violin, Tuesday, February 19, 2008
No full textIn partial fulfillment of the requirements for the degree of Master of Musi
Intrathoracic blood volume and global end-diastolic volume should be included among indexes used in intensive care for assessment of fluid responsiveness in spontaneously breathing patients : The authors reply
No full textReply to : Perel A. Intrathoracic blood volume and global end-diastolic volume should be included among indexes used in intensive care for assessment of fluid responsiveness in spontaneously breathing patients. Crit Care Med. 2006 Aug;34(8):2266-7; author reply 2267. doi: 10.1097/01.CCM.0000229645.81370.B8. PMID: 16883213, which is a comment on : Coudray A, Romand JA, Treggiari M, Bendjelid K. Fluid responsiveness in spontaneously breathing patients: a review of indexes used in intensive care. Crit Care Med. 2005 Dec;33(12):2757-62. doi: 10.1097/01.ccm.0000189942.24113.65. PMID: 16352956., accessible on : https://archive-ouverte.unige.ch/unige:182470</a
Short-Circuit Calculations in LV Cold Ironing Systems: Characteristic Currents Method CCM and IEC Method
No full textThis paper presents the calculation procedure of short
circuits adopting the CCM “Characteristic Currents Method”.
In a previous paper by the author Parise, the CCM has been
upgraded with the introduction of "characteristic"
countercurrents and the generalization of the Kirchhoff laws.
For illustrating the calculation procedure, the selected case study
deals with a low voltage cold ironing system where multiple ships
are allowed to operate simultaneously on one shore power
transformer and, so, a comparison has been developed between
the IEC approach of the short-circuit calculation and the CCM
Crayfish Carapace Micro-powder (CCM): A Novel and Efficient Adsorbent for Heavy Metal Ion Removal from Wastewater
No full textCrayfish carapace, a plentiful waste in China, was applied to remove divalent heavy metal ions—copper (Cu), cadmium (Cd), zinc (Zn), and lead (Pb)—from wastewater. The adsorption capacities of crayfish carapace micro-powder (CCM) for heavy metal ions were studied with adsorbent dosages ranging from 0.5–2.5 g/L and with initial metal concentrations ranging from 50–250 mg/L. CCM particle size, initial solution pH (from 2.5–6.5), temperature (from 25–65 °C) and calcium level (from 3.5–21.5%) were also varied in batch mode. The results indicated that the adsorption capacity increases with both decreasing particle size and increasing calcium level of the crayfish carapace. The kinetic studies indicated that the adsorption could be complete within 2 h, and that the data correlated with the pseudo-second-order model. CCM recorded maximum uptakes of 200, 217.39, 80, and 322.58 mg/g for Cu, Cd, Zn, and Pb, respectively. The adsorption capacities and removal efficiencies of CCM for metal ions were three-times higher than those of chitin and chitosan extracted from the CCM
Single-Phase PFC Boost Converter Operating in CCM with Active Input Filter Using Linear Regulator Assistance
No full textHard switching (PWM) converters with input or output smoothing inductors provide small current ripple at CCM. PFC stages need additionally a passive input filter usually formed by LC-Filter. This passive filter was replaced by an active filter, formed by a linear regulator, that compensates the input current ripple by draining the inductor current ripple to ground potential [1]. A 150 Watts PFC boost converter for line voltage input of 230 V was designed and built using CCM operation mode to minimize the current ripple. The remaining peak inductor current ripple of about 77.4 mA was reduced by linear regulator compensation to 12.0 mA peak input current ripple, what means 84.5 % ripple reduction, while input filter inductors and input filter capacitors were avoided. The power factor was 0.991 and the efficiency of the boost converter with the presented linear regulator assistance was 91.1%
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