To develop an efficient variable speed compressor motor system

This research presents a proposed new method of improving the energy efficiency of a Variable Speed Drive (VSD) for induction motors. The principles of VSD are reviewed with emphasis on the efficiency and power losses associated with the operation of the variable speed compressor motor drive, particularly at low speed operation.The efficiency of induction motor when operated at rated speed and load torque is high. However at low load operation, application of the induction motor at rated flux will cause the iron losses to increase excessively, hence its efficiency will reduce dramatically. To improve this efficiency, it is essential to obtain the flux level that minimizes the total motor losses. This technique is known as an efficiency or energy optimization control method. In practice, typical of the compressor load does not require high dynamic response, therefore improvement of the efficiency optimization control that is proposed in this research is based on scalar control model.In this research, development of a new neural network controller for efficiency optimization control is proposed. The controller is designed to generate both voltage and frequency reference signals imultaneously. To achieve a robust controller from variation of motor parameters, a real-time or on-line learning algorithm based on a second order optimization Levenberg-Marquardt is employed. The simulation of the proposed controller for variable speed compressor is presented. The results obtained clearly show that the efficiency at low speed is significant increased. Besides that the speed of the motor can be maintained. Furthermore, the controller is also robust to the motor parameters variation. The simulation results are also verified by experiment

The design of IPT system for multiple kitchen appliances using class E LCCL circuit

Since many years ago, kitchen appliances are powered up by cable connected. This create a troublesome case as wire might tangle together and cause kitchen table messy. Due to this, wireless power technology (WPT) is introduced as its ability is to transmit power to load without physical contact. This leads to cordless solution better in safety as the product can be completely seal, highly expandable power range. This work focuses on the design of WPT based on inductive approach to power up multiple kitchen appliances. The selection of inductive approach over its partners capacitive and acoustic is mainly due to high power efficiency. Class E inverter is proposed here to convert the DC to AC current to drive the inductive link. A 1 MHz operating frequency is used. To ensure the circuit is robust with load variations, an LCCL impedance matching is proposed. This solution is table to maintain the output power if there is a slight change in load impedance. Finally, the developed prototype is able to supply 50V utput which can achieve power transmission up to 81.76%

Interaction Design: Foundations, Experiments

Interaction Design: Foundations, Experiments is the result of a series of projects, experiments and curricula aimed at investigating the foundations of interaction design in particular and design research in general. The first part of the book - Foundations - deals with foundational theoretical issues in interaction design. An analysis of two categorical mistakes -the empirical and interactive fallacies- forms a background to a discussion of interaction design as act design and of computational technology as material in design. The second part of the book - Experiments - describes a range of design methods, programs and examples that have been used to probe foundational issues through systematic questioning of what is given. Based on experimental design work such as Slow Technology, Abstract Information Displays, Design for Sound Hiders, Zero Expression Fashion, and IT+Textiles, this section also explores how design experiments can play a central role when developing new design theory

Survey of hydrogen production and utilization methods. Volume 1: Executive summary

The use of hydrogen as a synthetic fuel is considered. Processes for the production of hydrogen are described along with the present and future industrial uses of hydrogen as a fuel and as a chemical feedstock. Novel and unconventional hydrogen-production techniques are evaluated, with emphasis placed on thermochemical and electrolytic processes. Potential uses for hydrogen as a fuel in industrial and residential applications are identified and reviewed in the context of anticipated U.S. energy supplies and demands. A detailed plan for the period from 1975 to 1980 prepared for research on and development of hydrogen as an energy carrier is included

Low-Frequency Series Loaded Resonant Inverter Characterization

Modern power systems require multiple conversions between DC and AC to deliver power from renewable energy sources. Recent growth in DC loads result in increased system costs and reduced efficiency, due to redundant conversions. Advances in DC microgrid systems demonstrate superior performance by reducing conversion stages. The literature reveals practical DC microgrid systems composed of wind and solar power to replace existing fossil fuel technologies for residential consumers. Although higher efficiencies are achieved, some household appliances require AC power; thus, the need for highly efficient DC to AC converters is imperative in establishing DC microgrid systems. Resonant inverter topologies exhibit zero current switching (ZCS); hence, eliminate switching losses leading to higher efficiencies in comparison to hard switched topologies. Resonant inverters suffer severe limitations mainly attributed to a load dependent resonant frequency. Recent advancements in power electronics propose an electronically tunable inductor suited for low frequency applications [24], [25]; as a consequence, frequency stability in resonant inverters is achievable within a limited load range. This thesis characterizes the operational characteristics of a low-frequency series loaded resonant inverter using a manually tunable inductor to achieve frequency stability and determine feasibility of utilization. Simulation and hardware results demonstrate elimination of switching losses via ZCS; however, significant losses are observed in the resonant inductor which compromises overall system efficiency. Additionally, harmonic distortion severely impacts output power quality and limits practical applications

Lessons Learned and Next Steps in Energy Efficiency Measurement and Attribution: Energy Savings, Net to Gross, Non-Energy Benefits, and Persistence of Energy Efficiency Behavior

This white paper examines four topics addressing evaluation, measurement, and attribution of direct and indirect effects to energy efficiency and behavioral programs: Estimates of program savings (gross); Net savings derivation through free ridership / net to gross analyses; Indirect non-energy benefits / impacts (e.g., comfort, convenience, emissions, jobs); and, Persistence of savings

Life cycle assessment of nanocellulose-reinforced advanced fibre composites

The research and development of nanocellulose-reinforced polymer composites have dramatically increased in the recent years due to the possibility of exploiting the high tensile stiffness and strength of nanocellulose. In the work, the environmental impacts of bacterial cellulose (BC)- and nanofibrillated cellulose (NFC)-reinforced epoxy composites were evaluated using life cycle assessment (LCA). Neat polylactide (PLA) and 30% randomly oriented glass fibre-reinforced polypropylene (GF/PP) composites were used as benchmark materials for comparison. Our cradle-to-gate LCA showed that BC- and NFC-reinforced epoxy composites have higher global warming potential (GWP) and abiotic depletion potential of fossil fuels (ADf) compared to neat PLA and GF/PP even though the specific tensile moduli of the nanocellulose-reinforced epoxy composites were higher than neat PLA and GF/PP. However, when the use phase and the end-of-life of nanocellulose-reinforced epoxy composites were considered, the “green credentials” of nanocellulose-reinforced epoxy composites were comparable to that of neat PLA and GF/PP composites. Our life cycle scenario analysis showed that the cradle-to-grave GWP and ADf of BC- and NFC-reinforced epoxy composites could be lower than neat PLA when the composites contains more than 60 vol.-% nanocellulose. Our LCA model suggests that nanocellulose-reinforced epoxy composites with high nanocellulose loading is desired to produce materials with “greener credentials” than the best performing commercially available bio-derived polymer

Smart kitchen for Ambient Assisted Living

El envejecimiento de la población es una realidad en todos los países desarrollados. Las predicciones de crecimiento de esta población son alarmantes, planteando un reto para los servicios sociales y sanitarios. Las personas ancianas padecen diversas discapacidades que se van acentuando con la edad, siendo más propensas a sufrir accidentes domésticos, presentando problemas para realizar tareas cotidianas, etc. Esta situación conlleva a una pérdida paulatina de capacidades que en muchas ocasiones acaba con la vida autónoma de la persona. En este contexto, las Tecnologías de la Información y Comunicación (TIC) aplicadas al entorno doméstico pueden jugar un papel importante, permitiendo que las personas ancianas vivan más tiempo, de forma independiente en su propio hogar, presentando, por tanto, una alternativa a la hospitalización o institucionalización de las mismas. Este trabajo da un paso más en este sentido, presentando el diseño y desarrollo de un Ambiente Inteligente en la cocina, que ayuda a las personas ancianas y/o con discapacidad a desempeñar sus actividades de la vida diaria de una forma más fácil y sencilla. Esta tesis realiza sus principales aportaciones en dos campos: El metodológico y el tecnológico. Por un lado se presenta una metodología sistemática para extraer necesidades de colectivos específicos a fin de mejorar la información disponible por el equipo de diseño del producto, servicio o sistema. Esta metodología se basa en el estudio de la interacción Hombre-Máquina en base a los paradigmas y modelos existentes y el modelado y descripción de las capacidades del usuario en la misma utilizado el lenguaje estandarizado propuesto en la Clasificación Internacional del Funcionamiento, de la Discapacidad y de la Salud (CIF). Adicionalmente, se plantea el problema de la evaluación tecnológica, diseñando la metodología de evaluación de la tecnología con la finalidad de conocer su accesibilidad, funcionalidad y usabilidad del sistema desarrollado y aplicándola a 61 usuarios y 31 profesionales de la gerontología. Desde un punto de vista técnico, se afronta el diseño de un ambiente asistido inteligente (Ambient Assisted Living, AAL) en la cocina, planteando y definiendo la arquitectura del sistema. Esta arquitectura, basada en OSGi (Open Services Gateway initiative), oferta un sistema modular, con altas capacidades de interoperabilidad y escalabilidad. Además, se diseña e implementa una red de sensores distribuida en el entorno con el fin de obtener la mayor información posible del contexto, presentando distintos algoritmos para obtener información de alto nivel: detección de caídas o localización. Todos los dispositivos presentes en el entorno han sido modelados utilizando la taxonomía propuesta en OSGi4AmI, extendiendo la misma a los electrodomésticos más habituales de la cocina. Finalmente, se presenta el diseño e implementación de la inteligencia del sistema, que en función de la información procedente del contexto y de las capacidades del usuario da soporte a las principales actividades de la vida diaria (AVD) en la cocina

PRACTICAL BASIS OF TEACHING MECHANICAL ENGINEERING TERMS

This article explains the need for the research in the field of engineering terminology, the process of teaching it in foreign languages, the comparative application of engineering terms in different languages and studying the development trends. Objective of the article is to describe the methodology of teaching mechanical engineering terminology on the basis of study research in the field of mechanical engineering as a complex of heavy equipment in industry that produces household appliances, as well as consumer electronics and products of defense importance. Methods of the investigation that enabled to: study and analyze mechanical engineering terms; develop methodology of teaching mechanical engineering terms; analyze selection and assessment criteria of case studies; analyze selection and assessment criteria of project-based teaching; organize pedagogical experiments and analyze their results. It is an integral part to investigate the sphere of machine-building and metalworking industries, the production of metal products, metal structures and the repair of machinery and equipment. Furthermore, the issues of teaching engineering terminology in order to form professional foreign language competence in technical students by means of using new pedagogical technologies are of high significance. Such as, typology of terms in the field of mechanical engineering, teaching terminology whereby case studies and projects, examples of case studies and study projects are given. It is also important to pay attention to the etymology and the sources of the formation of terms, their peculiarities and definitions in special contexts as a complex human speech and language activity. Results and discussion. The article discloses the processes of activating terminology for obtaining information, through cognitive activity. Research works in the field of mechanical engineering, the practical basis of teaching terms and its effectiveness are also analyzed. The terms, vocabulary related to the field of mechanical engineering, case studies and analysis of independent work assignments are taken into account in the organization and conducting the trainings defined in the pedagogical experiment. As a result of experimental research, it was proved by mathematical statistical methods that the efficiency was achieved by 15% in case studies and 17% in educational projects. It was found that the mean value of the scores in the experimental group was 17% higher than in the control group. Hence, the research conducted has proven to be effective. Conclusions. The difficulties that arise in the process of comparing terminological activities show not only the specificity of individual languages, but also the specific role of terms in the national language system. Comparing the terminology of the English and Uzbek languages in the field of mechanical engineering not only allows to determine the general and specific features of the terms of mechanical engineering in the two languages, but also provides an in-depth study of both terminological systems