Preparation and evaluation of advanced electrocatalysts for phosphoric acid fuel cells

Results are presented for hydrogen oxidation and hydrogen oxidation poisoned by carbon monoxide at levels between 0 and 30%. Due to the high activities that are now being observed for our platinum based electrocatalysts, the hydrogen concentrations were reduced to 10% levels in the gas supplies. Perturbation techniques were used to determine that a mechanism for the efficient operation of our porous gas diffusion electrodes is diffusion of the carbon monoxide out of the electrode structure through the electrolyte film on the electro-catalyst. A survey of the literature on platinum group materials (PGM) was carried out so that an identification of successful electrocatalysts could be made. Two PGM electrocatalysts were prepared and performance data for hydrogen oxidation in hot phosphoric acid in the presence of high carbon monoxide concentrations showed that they matched the best platinum on carbon electrocatalysts but with an electrocatalyst cost that was half of the platinum catalyst cost

Preparation and evaluation of advanced catalysts for phosphoric acid fuel cells

The platinum electrocatalysts were characterized for their crystallite sizes and the degree of dispersion on the carbon supports. One application of these electrocatalysts was for anodic oxidation of hydrogen in hot phosphoric acid fuel cells, coupled with the influence of low concentrations of carbon monoxide in the fuel gas stream. In a similar way, these platinum on carbon electrocatalysts were evaluated for oxygen reduction in hot phosphoric acid. Binary noble metal alloys were prepared for anodic oxidation of hydrogen and noble metal-refractory metal mixtures were prepared for oxygen reduction. An exemplar alloy of platinum and palladium (50/50 atom %) was discovered for anodic oxidation of hydrogen in the presence of carbon monoxide, and patent disclosures were submitted. For the cathode, platinum-vanadium alloys were prepared showing improved performance over pure platinum. Preliminary experiments on electrocatalyst utilization in electrode structures showed low utilization of the noble metal when the electrocatalyst loading exceeded one weight percent on the carbon

Preparation and evaluation of advanced electrocatalysts for phosphoric acid fuel cells

Two cooperative phenomena are required the development of highly efficient porous electrocatalysts: (1) is an increase in the electrocatalytic activity of the catalyst particle; and (2) is the availability of that electrocatalyst particle for the electromechanical reaction. The two processes interact with each other so that improvements in the electrochemical activity must be coupled with improvements in the availability of the electrocatalyst for reaction. Cost effective and highly reactive electrocatalysts were developed. The utilization of the electrocatalyst particles in the porous electrode structures was analyzed. It is shown that a large percentage of the electrocatalyst in anode structures is not utilized. This low utilization translates directly into a noble metal cost penalty for the fuel cell

Signal-to-noise ratio of Gaussian-state ghost imaging

The signal-to-noise ratios (SNRs) of three Gaussian-state ghost imaging configurations--distinguished by the nature of their light sources--are derived. Two use classical-state light, specifically a joint signal-reference field state that has either the maximum phase-insensitive or the maximum phase-sensitive cross correlation consistent with having a proper $P$ representation. The third uses nonclassical light, in particular an entangled signal-reference field state with the maximum phase-sensitive cross correlation permitted by quantum mechanics. Analytic SNR expressions are developed for the near-field and far-field regimes, within which simple asymptotic approximations are presented for low-brightness and high-brightness sources. A high-brightness thermal-state (classical phase-insensitive state) source will typically achieve a higher SNR than a biphoton-state (low-brightness, low-flux limit of the entangled-state) source, when all other system parameters are equal for the two systems. With high efficiency photon-number resolving detectors, a low-brightness, high-flux entangled-state source may achieve a higher SNR than that obtained with a high-brightness thermal-state source.Comment: 12 pages, 4 figures. This version incorporates additional references and a new analysis of the nonclassical case that, for the first time, includes the complete transition to the classical signal-to-noise ratio asymptote at high source brightnes

Aplikasi Fotogrammetri Rentang Dekat Untuk Pemodelan 3d Gedung a Lawang Sewu

[Close Range Photogrammetry Application for 3D Modelling of Lawang Sewu Building A] Close range photogrammetry is a one of photogrammetry applications. It can be used for the object measurement that is less than 100 meters. It also usualy used in 3D modeling of buildings, vehicles or bridges etc. In this final task, close range photogrammetry method was used for 3D modeling of Lawang Sewu Building A using non-metric digital camera. Initially, the camera must through of calibration process to determine the camera internal parameters. The process of calibration and data processing in this final task are using PhotoModeler Scanner v.7 2013 software. Phase of buildings modeling contain of marking and referencing, calculating and 3D modeling, transformation of 3D coordinate and visualization of 3D models. The data used are the photos that taken all around Lawang Sewu building A. The final results in this research are 3D model of Lawang Sewu Building A. Testing of the results in 3D modelling processing were done by comparing the 3D model distance referenced to Electronic Total Station measurement and statistics test with level of trust 95%. The statistics test in this research shows that there are no significant difference between ETS measurement

The age-mortality curve of endemic pleural mesothelioma in Karain, Central Turkey.

Scopu

How Do You Get Student Buy-In to A Wonderful (to You) Teaching Innovation?

One difficulty in adopting new classroom tools is persuading students to accept an educational technique out of their comfort zone. Our study investigated student perceptions when Calibrated Peer Review (CPR)™, a web-based program that uses writing for learning and assessing, was introduced into a general chemistry college classroom, and the strategies that helped convert initial intense opposition into acceptance and engagement. We will share the mistakes made, the reasons for students\u27 like or dislike of CPR, the 4 year path taken to understand the issues and modify its implementation for a more positive classroom experience, and why the instructor persisted in the face of resistance. Our findings can be generalized easily to the introduction of any new teaching tool. The audience will have opportunities to pair/share with neighbors about their good, bad and ugly experiences with a teaching innovation and two easy statistical data-handling methods will be explained

Duals of noncommutative supersymmetric U(1) gauge theory

Parent actions for component fields are utilized to derive the dual of supersymmetric U(1) gauge theory in 4 dimensions. Generalization of the Seiberg-Witten map to the component fields of noncommutative supersymmetric U(1) gauge theory is analyzed. Through this transformation we proposed parent actions for noncommutative supersymmetric U(1) gauge theory as generalization of the ordinary case.Duals of noncommutative supersymmetric U(1) gauge theory are obtained. Duality symmetry under the interchange of fields with duals accompanied by the replacement of the noncommutativity parameter \Theta_{\mu\nu} with \tilde{\Theta}_{\mu \nu} = \epsilon_{\mu\nu\rho\sigma}\Theta^{\rho\sigma} of the non--supersymmetric case is broken at the level of actions. We proposed a noncommutative parent action for the component fields which generates actions possessing this duality symmetry.Comment: Typos corrected. Version which will appear in JHE

New Estimates of Factor Income Shares in Central Asian Economies

This paper illustrates a simple method to derive the income accounts in the context of limited macroeconomic data. The method is relevant for several developing countries where the statements on income are clearly absent and the national accounts are confined to statements on expenditure and/or value added. Furthermore, the method is illustrated for four Central Asian economies, namely Kazakhstan, Mongolia, Kyrgyzstan and Uzbekistan. A Cobb-Douglas factor utilisation function is then used to estimate factor income shares and the relative contributions of factors to economic growth. The analysis reveals limited contribution of labour to economic growth in these economies. This limitation appears to be strongest in the resource dependent economies of Kazakhstan and Mongolia