Physics Based Electrolytic Capacitor Degradation Models for Prognostic Studies under Thermal Overstress

Electrolytic capacitors are used in several applications ranging from power supplies on safety critical avionics equipment to power drivers for electro-mechanical actuators. This makes them good candidates for prognostics and health management research. Prognostics provides a way to assess remaining useful life of components or systems based on their current state of health and their anticipated future use and operational conditions. Past experiences show that capacitors tend to degrade and fail faster under high electrical and thermal stress conditions that they are often subjected to during operations. In this work, we study the effects of accelerated aging due to thermal stress on different sets of capacitors under different conditions. Our focus is on deriving first principles degradation models for thermal stress conditions. Data collected from simultaneous experiments are used to validate the desired models. Our overall goal is to derive accurate models of capacitor degradation, and use them to predict performance changes in DC-DC converters

Aluminum Production Costs: A Comparative Case Study of Production Strategy

Slumping world aluminum prices have energized some aluminum producers to institute strategies to reduce product costs. This multiple comparative case study explored the strategies used by 4 aluminum producers in Western Europe: 2 companies that have successfully reduced production costs and 2 companies that have not. Wicksteed\u27s economic theory of production and production costs was the conceptual framework for this research. Data from the companies\u27 strategic and industry reports and from interviews with 32 senior managers were analyzed using pattern finding and clustering, a recursive approach to data gathering and analysis established by Miles, Huberman, and Saldana. Six themes emerged: (a) upstream integration, (b) energy and price efficiency, (c) carbon-manufacturing capability, (d) operational excellence and productivity, (e) technological and research developmental abilities, and (f) circular economy. The analysis of these themes indicated that the most significant opportunities for productivity improvement include (a) minimizing energy and material use, specifically alumina, cathodes, and carbon, (b) vertically integrating alumina production, (c) developing an efficient circular economic model that integrates the material properties to expand the recyclability of waste, and (d) increasing the electrolytic cell life cycle. Overall, vertical integration provides a competitive advantage and gives the producer ability to control costs. In-house carbon manufacturing capacity reduces a smelter\u27s operating cost. Technological capabilities can minimize energy and material consumption rates. Increased productivity and reduced energy and material use can yield positive social changes, such as the preservation of natural resources, reduced emissions, and waste

Optimization of electrolytic anodization of Ti-6Al-7Nb surfaces

Treballs Finals de Grau d'Enginyeria Biomèdica. Facultat de Medicina i Ciències de la Salut. Universitat de Barcelona. Curs: 2021-2022. Director: Javier Fernández González. Tutora: Raisha Lorena García Cadme.Increased life expectancy leads to the increasing use of metallic prostheses. Titanium and its alloys are the most widely used materials for metallic prostheses thanks to their biocompatibility, but further work still necessary to improve bioactivity and reduce osseointegration problems. Developing nanostructured titanium dioxide (TiO2) coatings increases the biocompatibility of titanium prostheses. Using the electrolytic anodizing process, nanostructures can be achieved easily and economically. This project aims to optimize the voltage and anodizing time conditions to obtain titanium dioxide nanotubes on the surface of Ti-6Al-7Nb alloy, as well as to propose ideas for industrial implementation of the project. To this purpose, a market study, a project implementation plan and a technical and economic feasibility analysis were carried out. An electron microscope image processing method and a rigorous statistical analysis have been studied to obtain an average pore diameter quantify the effect of the studied variables. Potentials of 15, 30 and 60 volts and anodizing times of 15 and 30 minutes were studied. The effect of the concentration of fluoride ions and the type of cathode used in anodizing has also been studied. The optimum conditions for the smallest pore size we have found are anodizing at 15V and 15 minutes, with a grid cathode. With these conditions, an average pore diameter of 0,48 ± 0,05 μm was obtained

Electrolysis

Asking Google for different applications of electrolysis, interesting results can be noticed: electrolysis and hair removal - about 284 000 000 web pages, water electrolysis - about 7 440 000 web pages and industrial electrolysis - about 2 540 000 results. In this book three most important applications of technological electrolysis are discussed - water electrolysis (hydrogen production), industrial electrolysis and environmental electrolysis. Authors of the chapters are recognized specialists in their respective research fields and the presented material is not only from reviews and literature sources, but also original results. We hope that the reader will find useful information in the chapters of this book and are certain that the science can reveal unexpected discoveries even tomorrow, if current progress is at hand or on a shelf

New Technologies in the Oil and Gas Industry

Oil and gas are the most important non-renewable sources of energy. Exploring, producing and managing these resources in compliance with HSE standards are challenging tasks. New technologies, workflows and procedures have to be implemented.This book deals with some of these themes and describes some of the advanced technologies related to the oil and gas industry from HSE to field management issues. Some new technologies for geo-modeling, transient well testing and digital rock physics are also introduced. There are many more technical topics to be addressed in future books. This book is aimed at researchers, petroleum engineers, geoscientists and people working within the petroleum industry

Nanotechnology for energy saving: nano-product (system)-concept design

PFC del programa Erasmus EPS elaborat a International Faculty of Engineering LodzTreball desenvolupat dins el marc del programa 'European Project Semester'.This project aims to investigate possible energy savings that nanotechnology can bring to a conventional house, and build and test a capacitor constructed with bucky paper in the laboratory. To accomplish the first objective, we will focus on four main areas and we will study how to improve it with nanotechnology: 1. Generation: How to improve solar panels, fuel cells and wind turbines. These devices allow us to generate energy through natural sources, like the sun and wind and reduce the use of energy sources, traditional finite and polluting, such as crude oil. 2. Conversion: How to improve lighting and appliances to avoid a significant loss of energy when converting electricity into light or running appliances. Also to use the organic matter and convert waste into biogas. 3. Insulation: How to increase the isolation of a house using nanomaterials to help keep the house warm in winter and cool in summer, therefore saving on heating and air conditioning expenses. 4. Storage: How to improve batteries and capacitors to increase energy storage capacity so that it can be accessed when needed. To complete the second goal, in the laboratory we will build a bucky paper capacitor and also compare it with standard and super capacitors

Electrolytic purification of water

This thesis develops the concept of an in situ electrolytic processor, a machine with electrochemical functions that purifies aqueous fluids at the point of production, whether from a bore water supply or effluent from a tannery. Where the contaminants in an effluent are useful they are separated in a specialised electrolyser for re-use in the process that produced the original effluent. The value in doing this exceeds the cost of electrolytic processing for tannery effluent. The functions of an electrolytic purifier were resolved into: flotation by bubbles, flocculation by corrosion of aluminium anodes, electrowinning by cathodic plating, disinfection, oxidation-reduction and pH modification. Improved understanding of the control of these functions has led to the ability to design better electrolysers because the functions were combined in a form that was appropriate to the required purification process. A link between extra-faradic corrosion of an aluminium anode and pH modification is postulated. Electrochemical principles were used as the basis for development of real processor models. These models were tested using bore water, cooling tower fluid, virus contaminated water, laundry water, municipal waste water, landfill leachate and pulp mill effluent. The most effective model, designed during the course of the project and described as the Flume, incorporated a novel corroding anode composed of thin pieces of aluminium, water flow in a cathodic flume, and a cheap water-porous membrane to separate the electrolyte into anolyte and catholyte. The novel anode was designed to improve clearance of corrosion products by maintaining a fast flow speed in proximity to the zone of anodic corrosion. The Flume model was used in an extensive test at a tannery. Greater than 90% of chromium in tannery effluent was removed by a combination of electroflocculation and electroflotation, at a lower cost than by treatment using standard chemical flocculent, using a side-stream Flume processor at a tannery. A smaller scale Flume model was used to test mechanisms of treatment in the laboratory using synthetic tannery effluent. When treating alkaline effluent, the separating membrane in the Flume model enabled production of alkali at the cathode and production of acid at the anode. This was used for pH modification of effluent and, where the majority of the flow was anolyte, was able to produce a catholyte of pH greater than 13 from a wide range of inflow pH. The caustic catholyte is a valuable by-product of the electrolytic processing, especially when the upstream processes require net input of alkali (as is the case at a tannery or kraft pulp mill) and more generally because downstream biological treatment processes benefit from receiving neutralised effluent. The degree of pH moderation of the whole outflow compared to the inflow was found to be controllable by adjustment of cell voltage. This effect enables treatment of effluent with variable pH. Optimisation of an electrolyser for energy recovery, by both reduction of electrode over-potentials and electrolyte resistance, was incorporated in the full-scale designs. Based on a feasible cell voltage of 5 V, 20% recovery of the energy input is expected

Index to NASA Tech Briefs, 1974

The following information was given for 1974: (1) abstracts of reports dealing with new technology derived from the research and development activities of NASA or the U.S. Atomic Energy Commission, arranged by subjects: electronics/electrical, electronics/electrical systems, physical sciences, materials/chemistry, life sciences, mechanics, machines, equipment and tools, fabrication technology, and computer programs, (2) indexes for the above documents: subject, personal author, originating center

Management and Applications of Energy Storage Devices

This book reviews recent trends, developments, and technologies of energy storage devices and their applications. It describes the electrical equivalent circuit model of batteries, the technology of battery energy storage systems in rooftop solar-photovoltaic (PV) systems, and the implementation of second-life batteries in hybrid electric vehicles. It also considers a novel energy management control strategy for PV batteries operating in DC microgrids, along with the present state and opportunities of solid-state batteries. In addition, the book examines the technology of thin-film energy storage devices based on physical vapor deposition as well as the challenges of ionic polymer-metal composite membranes. Furthermore, due to the novel battery technology in energy storage devices, this book covers the structural, optical, and related electrical studies of polyacrylonitrile (PAN) bearing in mind the applications of gel polymer electrolytes in solid-state batteries. Since energy storage plays a vital role in renewable energy systems, another salient part of this book is the research on phase change materials for maximum solar energy utilization and improvement. This volume is a useful reference for readers who wish to familiarize themselves with the newest advancements in energy storage systems