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81.
Oxidation of formic acid at a high surface area supported platinum modified by foreign metal adatoms
The anodic oxidation of formic acid was studied on platinum distributed in the form of small particles in a porous substrate modified by metal adatoms deposited at underpotentials. The rate of the reaction was greatly enhanced on the commercial catalyst Powercat 3000 (PC 3000). The hydrogen adsorption and the underpotential deposition of several metals at PC 3000 were shown to be dissimilar to that at smooth polycrystalline Pt. Steady-state and long-term experiments were performed to determine the stability of this electrode. 相似文献
82.
LJ Porrino L Williams-Hemby C Whitlow C Bowen HH Samson 《Canadian Metallurgical Quarterly》1998,22(1):176-182
A method for the quantitation of protein carbonyls, which have been widely employed as markers of protein oxidative damage, is described. Protein carbonyls were derivatized with tritiated sodium borohydride and the tritiated proteins were separated on SDS-PAGE. Protein bands, visualized by Coomassie blue staining, were then excised and incubated in 30% H2O2 at 60 degrees C for 48 h. Tritium, incorporated into the proteins, was quantitated by liquid scintillation counting after gel solubilization by H2O2. This method can be applied to the measurement of carbonylation of specific proteins as it employs SDS-PAGE and has the advantage that unreacted NaB3H4 in the labeling reaction mixture need not be removed. The present method, when combined with immunochemical detection of protein carbonyls, should be very useful in the quantitation of oxidative damage to individual proteins. 相似文献
83.
BA McCracken MB Judkins LJ Krysl DW Holcombe KK Park 《Canadian Metallurgical Quarterly》1993,71(7):1932-1939
Two experiments were conducted to study the effects of methionine supplementation on ruminal fermentation and digesta kinetics. In Exp. 1, nine ruminally cannulated beef heifers (average initial BW = 527 kg) in a crossover design were fed low-quality grass hay and cottonseed meal with or without 11.4 g of supplemental methionine (polysaccharide-coated). Particulate and fluid kinetics, rate of DM and NDF disappearance, ruminal VFA and NH3 N concentrations, and pH were not altered (P > .10) by supplemental methionine; however, ruminal purine concentration was greater (P < .05) in methionine-supplemented heifers than in unsupplemented heifers. In Exp. 2, 12 ruminally cannulated Holstein steers (average initial BW = 622 kg) grazing a fescue pasture were allotted to one of three groups: no supplemental methionine (CON) or 11.4 g of supplemental methionine fed at 0700 (AM) or at 1200 (PM). Forage intake, particulate kinetics, ruminal fluid kinetics, pH, VFA, and NH3 N concentrations were not altered (P > .10) by supplemental methionine or supplementation time. In situ rate of DM and NDF disappearance was greater (P < .05) in supplemented steers than in CON steers; AM steers exhibited faster (P < .05) rates than PM steers. Overall, methionine supplementation of low-quality forage increased ruminal purine concentration but did not alter in situ fermentation or digesta passage, whereas supplementation at 0700, but not at 1200, of steers grazing fescue forage increased rate of NDF fermentation. 相似文献
84.
LJ Seidman J Biederman W Weber M Hatch SV Faraone 《Canadian Metallurgical Quarterly》1998,44(4):260-268
Pacemaker therapy in patients with atrial fibrillation means the best current pacemaker therapy for patients with bradycardias with the aim to avoid the onset of atrial fibrillation and to establish DDD pacing despite of a history of atrial tachyarrhythmias. The newer application of pacing is the suppression of atrial arrhythmias in patients with medical refractory atrial tachyarrhythmias. Patients with slow ventricular rates and permanent atrial fibrillation should receive a VVI-pacemaker, if the bradycardias causes syncope, dizziness or a decrease of their exercise tolerance. In case of chronotropic incompetence the pacemaker should provide rate responsive pacing. Patients with sick sinus syndrome should receive an atrial (AAI) or dual-chamber (DDD) pacemaker, because patients with these in contrast to VVI-pacemakers develop less often atrial fibrillation and subsequent complications such as atrial thromboembolism. A dual-chamber or VDD-pacemaker--the latter connected to a VDD-single-lead--is indicated in patients with advanced AV-block. Atrial fibrillation occurs in 3 to 6% of the patients with no history of arrythmia and is, if pacemakers have no automatic mode switch, an often reason to program the devices to the VVI-pacing mode. Nowadays, most DDD(R)-pacemakers provide an automatic mode switch: During an atrial tachycardia the pacemaker switches to a VVI/VVIR mode and restores the initial DDD(R)-pacing mode with termination of the arrhythmia. In respect to the newer applications, one approach to prevent atrial tachyarrhythmias is permanent atrial pacing. As lower pacing rates of 80 to 90 ppm are usually needed and many patients hardly tolerate these pacing rates, new algorithms are under clinical investigation. Another approach is the simultaneous depolarization of the right and left atrium. Biatrial pacing is performed with one lead in the high right atrium and another lead in the coronary sinus. Another solution is bifocal atrial pacing with leads placed in the high right atrium and in the coronary sinus ostium. One effect of the new pacing techniques is to shorten interatrial conduction times. Therefore, biatrial pacing has become a therapy to prevent atrial arrhythmias deriving from delayed interatrial conduction times. As atrial reentry circuits seem to be important in atrial fibrillation, multisite atrial pacing is also performed in patients with medical refractory paroxysmal atrial fibrillation. Preliminary results suggest a more effective prevention of atrial fibrillation; nevertheless, these techniques should be still restricted to patients enrolled in clinical studies. 相似文献
85.
D. C. Hermes T. Heuser E. J. van der Wouden J. G. E. Gardeniers A. van den Berg 《Microsystem Technologies》2006,12(5):436-440
In this paper a method is presented for the fabrication of micro-channel networks in glass with integrated and insulated gate electrodes to control the zeta-potential at the insulator surface and therewith the electro-osmotic flow (EOF). The fabrication of the electrodes is a sequence of photolithography, etching and thin film deposition steps on a glass substrate, followed by chemical mechanical polishing (CMP) and subsequently direct thermal bonding to a second glass plate to form closed micro-channels. Plasma enhanced chemical vapor deposition (PECVD) SiO2-layers as insulating material between the electrodes and micro-channels and different electrode materials are examined with respect to a high bonding temperature to obtain an optimal insulating result. A CMP process for the reduction of the SiO2 topography and roughness is studied and optimized in order to obtain a surface that is smooth enough to be directly bondable to a second glass plate. 相似文献
86.
P. Berg 《European Food Research and Technology》1932,64(4):357-362
87.
Xuesong Liu Burcu Akinci Mario Bergés James H. Garrett 《Advanced Engineering Informatics》2013,27(4):496-505
Heating, Ventilation and Air-Conditioning (HVAC) systems account for more than 15% of the total energy consumption in the US. In order to improve the energy efficiency of HVAC systems, researchers have developed hundreds of algorithms to automatically analyze their performance. However, the complex information, such as configurations of HVAC systems, layouts and materials of building elements and dynamic data from the control systems, required by these algorithms inhibits the process of deploying them in real-world facilities. To address this challenge, we envision a framework that automatically integrates the required information items and provides them to the performance analysis algorithms for HVAC systems. This paper presents an approach to identify and document the information requirements from the publications that describe these algorithms. We extend the Information Delivery Manual (IDM) approach so that the identified information requirements can be mapped to multiple information sources that use various formats and schemas. This paper presents the extensions to the IDM approach and the results of using it to identify information requirements for performance analysis algorithms of HVAC systems. 相似文献
88.
This paper examines factors contributing to the effectiveness of camera operators in urban camera surveillance. The use of camera surveillance has taken an enormous flight in the past decades. Despite this increase, its effectiveness is strongly debated. One reason for the disputed effectiveness may be that an understanding of how to use camera surveillance, including elements contributing to the effectiveness of camera operators, has not kept track with technological developments. This paper focuses on the role of expertise and familiarity with the environment on the effectiveness of camera operators to detect offenders in video footage from Rotterdam City Surveillance in the Netherlands. Results show no effect of expertise, but do show that familiarity with the location contributes to operator effectiveness and that camera operators seem to use different criteria for detecting and selecting suspects depending on the familiarity with the location. These results contribute to our understanding of operator effectiveness and offer guidelines for the training of camera operators. Implications are discussed. 相似文献
89.
T. Adachi M.N. HarakehN. Kalantar-Nayestanaki H.J. WörtcheG.P.A. Berg H. SimonI.A. Koop M. CouderM. Fujiwara 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,659(1):198-206
For the study of electron-scattering off radioactive nuclei, the ELISe spectrometer will be constructed as a part of the Facility of Antiprotons and Ion Research (FAIR) in Darmstadt. A conceptional design of a spectrometer with a “clam-shell” gap was presented before. Here, we will present an improved design with a pre-deflector with a constant gap. Such a pre-deflector is not only simpler to construct but also provides larger angle acceptances in the forward-angle range compared to those with the “clam-shell” design. 相似文献
90.
Al GarrenJ.S. Berg D. ClineX. Ding H.G. Kirk 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,654(1):40-44
Six dimensional cooling of large emittance μ+ and μ− beams is required in order to obtain the desired luminosity for a muon collider. We propose to use a ring cooler that employs both dipoles and solenoids with the additional requirement that the arcs of the ring be achromatic. We describe the lattice and the beam dynamics of the proposed ring, and demonstrate that the lattice gives substantial cooling in all 6 phase space dimensions. 相似文献