Glucose fuel cells with nano-fibrous anodes

Transcription

1 Glucose fuel cells with nano-fibrous anodes Eugenia Bubis 1, Ehud Kroll 2, Hana Faiger 3, Pinchas Schechner 4 1 Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , jbubis@braude.ac.il 2 Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , ekroll@braude.ac.il 3 Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , hfaiger@yahoo.com 4 Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , pschechner@braude.ac.il Keywords: Power, glucose, alkaline fuel cell, charge double layer The efficiency of fuel cells is determined by the power they supply. Supplied power depends on such parameters as maximum output voltage, maximum limiting current and internal resistance of the fuel cell. The electrical current of an Alkaline Fuel Cell is determined by two types of processes that occur at the electrodes: faradaic and non-faradaic. Faradaic processes comprise reactions in which charges (i.e., electrons) are transferred across the metal solution interface. Electron transfer causes oxidation or reduction and is governed by Faraday s law (i.e. the amount of chemical reaction caused by the flow of current is proportional to the amount of electricity passed). Non-faradaic processes comprise of reactions in which charged particles, such as electrons, cannot pass across the interface barrier. Non-faradaic processes, such as adsorption or desorption, are caused in turn by changes of the electrode s potential. Both faradaic and nonfaradaic processes depend on the microscopic electrode area. The objective of the current research is to study how the fiber s diameter of the anode electrodes influences the efficiency of Alkaline Fuel Cells. The effect of the fiber s diameter of the anodes on the power density and internal resistance was tested. research committee. The 4th ORT Braude Interdisciplinary Research Conference 43

2 A lower bound approximation for system availability computation Radu Florescu Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , Keywords: Availability, Markov model, approximation, Boole inequality. In order to study the availability of a repairable system, one usually uses a Markov probability model. For complex systems, it is difficult to solve such a model because a system of coupled first order differential (or algebraic, in the steady state case) equations must be solved. The number of equations equals the number of system states. To overcome this difficulty, new methods to study the availability of complex systems have been studied. One method is to find bounds and approximations for the availability function, thus acquiring useful information on the basis of simple calculations. This paper discusses a simplified lower bound approximation for system availability computation. The analysis of system availability via Markov model computation becomes simpler by using this lower bound together with an upper bound. Such approximate studies are useful for systems which contain many states, but only if the interval between the two bounds is narrow enough. Based upon the Boole inequality, one can obtain a lower bound of system availability useful in engineering practice. An example, that proves the efficiency of the approximation presented in this paper, is presented. The 4th ORT Braude Interdisciplinary Research Conference 44

3 Algorithmic synthesis of a combinational adder of decimal digits encoded by the Johnson Mobius code Michael Gladshtein Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , mgladsht@braude.ac.il Keywords: Nanocomputer architecture, decimal number system, biquinary encoding of decimal digits, Johnson-Mobius code, decimal addition This paper presents the new results of the author's continuing research in the field of universal digital nanocomputer architecture, based on use of a decimal notation. The construction methods of a combinational adder of decimal digits encoded by the Johnson- Mobius code are investigated. The algorithmic method of a structural synthesis of a decimal adder is offered. The implementation of such an adder on quantum-dot cellular automata (QCA) is described. A successful computer simulation was performed. The evaluation of hardware costs and delay time is given in comparison with the traditional binary four-bit combinational adder. The results of this research permit recommendation of the developed adder as an element for the designing of a nanocomputer arithmetic unit. Acknowledgement: This study was supported by a scholarship Conversion of hours of teaching to hours of research from the ORT Braude College Research Committee. The 4th ORT Braude Interdisciplinary Research Conference 45

4 Robust color edge detector for the compact 3D scanner Samuel Kosolapov Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , Keywords: 3D Scanner, edge detector, color edge detector, image processing State-of-the-art Laser 3D Scanners can provide high XYZ accuracy, but their design requires usage of high precision mechanical members, which leads to an extremely slow 3D Data acquisition process and to a forbiddingly high (for many real-life applications) price. Structured Light 3D Scanners are less expensive and provide faster 3D Data Acquisition but have wellknown ambiguity problem. The newly designed Compact Structured Light 3D Scanner utilizes a Color Edge Pattern designed to solve ambiguity problem. The pattern consists of a sequence of a colored, black and white strips creating unique and non-unique color edges. The pattern is projected onto the surface- in-test by using a simple slide projector. Images of the surface-in-test (illuminated by the pattern) are grabbed by an inexpensive CMOS camera and processed by specially created image processing utilities. During 3D acquisition the process slide (containing the Color Edge Pattern) is shifted by inexpensive and non-exact mechanical means so that each time different parts of the surface-intest are illuminated by white strips. According to the newly developed approach, at least two images must be grabbed and processed. During the first stage of the image processing algorithm, pixels from different images illuminated by white strips are combined into a base image. Assuming that surface-in-test is not moved during the acquisition process, the resulting base image is a plain color image of the surface-in-test a feature not available in most Laser and Structured Lights scanners. Additionally, the base image is used in the decolorizing step, which leads to the elimination of uneven field artifacts and to the elimination of the color of the surface-in-test. Practically, after the decolorizing process, a set of images containing colored, black and white strips only is created the surface-in-test is seen as a gray object. During the second stage of the image processing algorithm, unique and non-unique color edges are extracted by a specially designed Robust Color Edge Detector. It is well known that Edge Detectors are very sensitive to camera noise and to defects of illumination. The structure of the pattern containing only a limited number of pre-defined colors, purified by a decolorizing process, enables detection of color edges in a very reliable (robust) manner. Operation of this Edge Detector includes a number of checks and specially designed procedures such as Smart DeGray, Closest Color by Scalar Product, Vote inside the Strip. Color edge positions {Row, Column} are calculated as a result of a 1D Convolution Filter application. During the third stage of the image processing algorithm, a set of {Row, Column} edge positions is transformed into a cloud of {X,Y,Z} points by using practically standard triangulation technique. After proper median and logical filtration, {X, Y, Z} points are organized as a mesh or STL file which is routed to a CNC machine or to a 3D printer for physical duplication of the surface-intest. Resulting {X, Y, Z} accuracy was evaluated as 0.3mm, which is adequate for the number of practical applications. research committee and by a TNUFA grant from the Office of the Chief Scientist of the Ministry of Trade and Industry. The 4th ORT Braude Interdisciplinary Research Conference 46

5 Inorganic glucose fuel cells accomplishments during Pinchas Schechner 1, Ehud Kroll 2, Hana Faiger 3, Eugenia Bubis 4 1 Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , pschechner@braude.ac.il 2 Department of Mechanical Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , ekroll@braude.ac.il 3 Department of Biotechnology Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , hfaiger@yahoo.com 4 Department of Electrical and Electronic Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , jbubis@braude.ac.il Keywords: Glucose, alkaline fuel cell, electrospinning We report the accomplishments achieved during the last year by the Inorganic Glucose Fuel Cell Group of the ORT Braude College. These include: (a) Development of the AFCMS, an automatic system for the measurement of fuel cell performance; (b) Integration of a Potentiostat into our laboratory facilities; and (c) Development of the technical means to avoid liquid leakage from alkaline fuel cells. In parallel, the development of the electro-catalytic anode in collaboration with the Technion has continued. The anodes, electrospun nanometric fiber membranes coated by electroless silver plating, were installed in dual compartment fuel cells. The best performance so far was recorded with a PAN based membrane, with fibers having a diameter of 0.969±0.120μm. We were able to obtain a Peak Power Density of 0.3 mw/cm 2. research committee. The 4th ORT Braude Interdisciplinary Research Conference 47

6 Aspects of thinking among undergraduate engineering students Elena Trotskovsky 1, Nissim Sabag 2 1 Department of Electrical and Electronics Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , elenatro@braude.ac.il 2 Department of Electrical and Electronics Engineering, ORT Braude College, P.O. Box 78, Karmiel 21982, Israel, Tel: , Fax: , nsabag@braude.ac.il Keywords: Engineering thinking, engineering design, internship Fast progress in the field of electrical and electronics engineering produces a huge amount of new knowledge. The limited time frame of undergraduate studies cannot cover all the information needed for Hi-Tech engineers. Therefore many researchers call on academia to deal with students skills rather than knowledge. Most of the graduates work as development engineers designing new sophisticated products. Integrating aspects of engineering thinking into the B.Sc. curriculum of electrical and electronics engineering can contribute to smooth and successful entrance of fresh graduates into industrial life. A large body of literature yielded no references to design education in the field of electrical and electronics engineering. The research presented here deals with the characterization of engineering thinking during the design of electrical and electronic industrial projects. We believe that it will contribute to and enhance the knowledge of design thinking education and engineering curriculum development. This research characterizes design thinking from the experienced engineers' point of view and analyzes students activities during their internship where they design their own first real project. Qualitative research methods such as interviews, monthly reports and final book analyses were used. The results show that synthesis, analysis, and decision making are not only design stages, they can be considered thinking modes. The synthesis, analysis, decision making, and reflection are not separate processes but interdependent. It was also found that internship contributes to systems thinking, end backward problem solving, alternative examination, engineering decision making, and reflection. research committee. The 4th ORT Braude Interdisciplinary Research Conference 48