Fabrication of polymer electrolyte membrane fuel cell MEAs utilizing inkjet print technology

Utilizing drop-on-demand technology, we have successfully fabricated hydrogen–air polymer electrolyte membrane fuel cells (PEMFC), demonstrated some of the processing advantages of this technology and have demonstrated that the performance is comparable to conventionally fabricated membrane electrode assemblies (MEAs). Commercial desktop inkjet printers were used to deposit the active catalyst electrode layer directly from print cartridges onto Nafion^® polymer membranes in the hydrogen form. The layers were well-adhered and withstood simple tape peel, bending and abrasion tests and did so without any post-deposition hot press step. The elimination of this processing step suggests that inkjet-based fabrication or similar processing technologies may provide a route to less expensive large-scale fabrication of PEMFCs. When tested in our experimental apparatus, open circuit voltages up to 0.87 V and power densities of up to 155 mW cm⁻² were obtained with a catalyst loading of 0.20 mg Pt cm⁻². A commercially available membrane under identical, albeit not optimized test conditions, showed about 7% greater power density. The objective of this work was to demonstrate some of the processing advantages of drop-on-demand technology for fabrication of MEAs. It remains to be determined if inkjet fabrication offers performance advantages or leads to more efficient utilization of expensive catalyst materials.     

Observations on the structural degradation of silver during simultaneous exposure to oxidizing and reducing environments

The structural stability of silver (Ag) in dual atmosphere exposure conditions, which are representative of solid oxide fuel cell (SOFC) current collector and gas seals, has been examined in the 600–800 °C temperature range. Experiments conducted on Ag tubular sections exposed to flowing H₂-3% H₂O (inside the tube) and air (outside the tube) showed extensive porosity formation along the grain boundaries in the bulk metal. Similar tubular sections, when exposed to air only (both inside and outside the tube), showed no bulk porosity or structural changes. It is postulated that the porosity formation in the bulk metal is related to the formation of gaseous H₂O bubbles due to simultaneous diffusion of hydrogen and oxygen followed by subsequent interaction resulting in the formation of steam. Thermochemical processes that are responsible for structural degradation are presented and discussed. Based on experimental observations, it is concluded that Ag metal may not provide adequate long-term structural stability under a dual-environment condition that is typical of interconnects or gas seals in intermediate temperature SOFCs. This paper was presented at the Fuel Cells: Materials, Processing, and Manufacturing Technologies Symposium sponsored by the Energy/Utilities Industrial Sector & Ground Transportation Industrial Sector and the Specialty Materials Critical Technologies Sector at the ASM International Materials Solutions Conference, October 13–15, 2003, in Pittsburgh, PA. The symposium was organized by P. Singh, Pacific Northwest National Laboratory, S.C. Deevi, Philip Morris USA, T. Armstrong, Oak Ridge National Laboratory, and T. Dubois, U.S. Army CECOM.     

Collaborative Network Transformation

The directions that a typical service provider is thinking along today are so varied. This paper will first take a look at some of the thoughts that are shaping a typical service provider’s mindset today. These thoughts stem from new technology options, increased competition, new and different customer behavior, and new business models. Based on today’s observations, combined with the desire to be prepared for the different opportunities and challenges they expect to see in the future, service providers have embarked upon a huge network transformation exercise. This paper will attempt to highlight the complexity such a network transformation exercise would entail. While they remain focused on their strategic initiatives, options for the service provider to partner with others to make the network transformation task a little easier will be explored. Should they choose to go with a network transformation partner, recommendations on how to choose and work with the right partner are provided.

Diamond synthesis at low temperatures

Diamond growth at room temperature [i.e., on unheated monocrystalline silicon (111) substrates], has been demonstrated by the laser irradiation of CO/H₂ gas mixtures at low pressures. The CO is photodissociated by a multiphoton process using 193 nm radiation from an excimer laser. This process, referred to as laser chemical vapor deposition (LCVD), is distinct from the laser-excited CVD (LECVD) process described in an earlier publication. Although no quantitative measurements have yet been made on the gas-phase species compositions in LCVD, the growth of diamond particles at room temperature marks a beginning to enabling diamond deposition on materials with low melting temperatures.     

Quantum-behaved bat algorithm for many-objective combined economic emission dispatch problem using cubic criterion function

In this research, a quantum computing idea based bat algorithm (QBA) is proposed to solve many-objective combined economic emission dispatch (CEED) problem. Here, CEED is represented using cubic criterion function to reduce the nonlinearities of the system. Along with economic load dispatch, emissions of SO₂, NO_x, and CO₂ are considered as separate three objectives, thus making it a four-objective (many-objective) optimization problem. A unit-wise price penalty factor is considered here to convert all the objectives into a single objective in order to compare the final results with other previously used methods like Lagrangian relaxation (LR), particle swarm optimization, and simulated annealing. QBA is applied in six-unit power generation system for four different loads. The obtained results show QBA successfully solve many-objective CEED problem with greater superiority than other methods found in the literature in terms of quality results, robustness, and computational performance. In the end of this paper, a detailed future research direction is provided based on the simulation results and its analysis. The outcome of this research demonstrates that the inclusion of quantum computing idea in metaheuristic technique provides a useful and reliable tool for solving such many-objective optimization problem.

     

Conjoint Knowledge Discovery Utilizing Data and Content with Applications in Business,Bio-medicine,Transport Logistics and Electrical Power Systems

In Digital Enterprises Structured Data and Semi/Unstructured Content are normally stored in two different repositories, with the first often being stored in relational Databases and the second in a content manager which is frequently at an external outsourcer. This storage of complementary information in two different silos has led to the information being processed and data mined separately which is undesirable. Effective knowledge and information use requires seamless access and intelligent analysis of information in its totality to allow enterprises to gain enhanced insights. In this paper, we develop techniques to carry out correlation of the information across different sources and then carryout out knowledge discovery across these complementary sources in a conjoint manner. The techniques developed in our research will then be used to address significant issues in four application areas namely Business, Logistics, Bioinformatics and Electric Power Systems but potential applications with significant impact are much more extensive.