391 research outputs found

    Constructing living buildings: a review of relevant technologies for a novel application of biohybrid robotics

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    Biohybrid robotics takes an engineering approach to the expansion and exploitation of biological behaviours for application to automated tasks. Here, we identify the construction of living buildings and infrastructure as a high-potential application domain for biohybrid robotics, and review technological advances relevant to its future development. Construction, civil infrastructure maintenance and building occupancy in the last decades have comprised a major portion of economic production, energy consumption and carbon emissions. Integrating biological organisms into automated construction tasks and permanent building components therefore has high potential for impact. Live materials can provide several advantages over standard synthetic construction materials, including self-repair of damage, increase rather than degradation of structural performance over time, resilience to corrosive environments, support of biodiversity, and mitigation of urban heat islands. Here, we review relevant technologies, which are currently disparate. They span robotics, self-organizing systems, artificial life, construction automation, structural engineering, architecture, bioengineering, biomaterials, and molecular and cellular biology. In these disciplines, developments relevant to biohybrid construction and living buildings are in the early stages, and typically are not exchanged between disciplines. We, therefore, consider this review useful to the future development of biohybrid engineering for this highly interdisciplinary application.publishe

    Synthesis and gas sensing properties of inorganic semiconducting, p-n heterojunction nanomaterials

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    En aquesta tesis utilitzant principalment Aerosol Assited Chemical Vapor Deposition, AACVD, com a metodologia de síntesis d'òxid de tungstè nanoestructurat s'han fabricat diferents sensors de gasos. Per tal d'estudiar la millora en la selectivitat i la sensibilitat dels sensors de gasos basats en òxid de tungstè aquest s'han decorat, via AACVD, amb nanopartícules d'altres òxids metàl·lics per a crear heterojuncions per tal d'obtenir un increment en la sensibilitat electrònica, les propietats químiques del material o bé ambdues. En particular, s'han treballat en diferents sensors de nanofils d'òxid de tungstè decorats amb nanopartícules d'òxid de níquel, òxid de cobalt i òxid d'iridi resultant en sensors amb un gran increment de resposta i selectivitat cap al sulfur d'hidrogen, per a l'amoníac i per a l'òxid de nitrogen respectivament a concentracions traça. A més a més, s'han estudiat els mecanismes de reacció que tenen lloc entre les espècies d'oxigen adsorbides a la superfície del sensor quan interactua amb un gas. I també s'ha treballat en intentar controlar el potencial de superfície de les capes nanoestructurades per tal de controlar la deriva en la senyal al llarg del temps, quan el sensor està operant, a través d'un control de temperatura.En esta tesis utilizando principalmente Aerosol Assited Chemical Vapor Deposition, AACVD, como metodología de síntesis de óxido de tungsteno nanoestructurado se han fabricado diferentes sensores de gases. Para estudiar la mejora en la selectividad y la sensibilidad de los sensores de gases basados en óxido de tungsteno estos se han decorado, vía AACVD, con nanopartículas de otros óxidos metálicos para crear heterouniones para obtener un incremento en la sensibilidad electrónica, las propiedades químicas del material o bien ambas. En particular, se han trabajado en diferentes sensores de nanohilos de óxido de tungsteno decorados con nanopartículas de óxido de níquel, óxido de cobalto y óxido de iridio resultante en sensores con un gran incremento de respuesta y selectividad hacia el sulfuro de hidrógeno, para el amoníaco y para el óxido de nitrógeno respectivamente a concentraciones traza. Además, se han estudiado los mecanismos de reacción que tienen lugar entre las especies de oxígeno adsorbidas en la superficie del sensor cuando interactúa con un gas. Y también se ha trabajado en intentar controlar el potencial de superficie de las capas nanoestructuradas para controlar la deriva en la señal a lo largo del tiempo, cuando el sensor está trabajando, a través de un control de temperatura.In this thesis, using mainly Aerosol Assited Chemical Vapor Deposition, AACVD, as a synthesis methodology for nanostructured tungsten oxide, different gas sensors have been manufactured. To study the improvement in the selectivity and sensitivity of gas sensors based on tungsten oxide, they have been decorated, via AACVD, with nanoparticles of other metal oxides to create heterojunctions to obtain an increase in electronic sensitivity, in the chemical properties of the material or at the same time in both. Particularly, we have worked on different tungsten oxide nanowire sensors decorated with nanoparticles of nickel oxide, cobalt oxide and iridium oxide resulting in sensors with a large increase in response and selectivity towards hydrogen sulfide, for ammonia. and for nitrogen oxide respectively at trace concentrations. In addition, the reaction mechanisms that take place between oxygen species adsorbed on the sensor surface when it interacts with a gas have been also studied. Furthermore, efforts have been put on trying to control the surface potential of the nanostructured layers to control the drift in the signal over time, when operating the sensors, through temperature control

    Space station systems: A bibliography with indexes (supplement 6)

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    This bibliography lists 1,133 reports, articles, and other documents introduced into the NASA scientific and technical information system between July 1, 1987 and December 31, 1987. Its purpose is to provide helpful information to the researcher, manager, and designer in technology development and mission design according to system, interactive analysis and design, structural and thermal analysis and design, structural concepts and control systems, electronics, advanced materials, assembly concepts, propulsion, and solar power satellite systems. The coverage includes documents that define major systems and subsystems, servicing and support requirements, procedures and operations, and missions for the current and future Space Station

    Detailed design of a class I UAV for maritime surveillance

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    ALFAL/ENGAER 138081-J João Correia. Examination Committee: Chairperson: MGEN/ENGAER 076441-J Paulo Manuel Veloso Gonçalves Guerra (DMSA); Supervisor: MAJ/ENGAER 129905-A Luís Filipe da Silva Félix (AFA); Supervisor: CAP/ENGAER 131603-G João Vítor Aguiar Vieira Caetano (AFA); Member of the Committee: Doutor Frederico José Prata Rente Reis Afonso (IST)Esta tese destina-se ao design estrutural em materiais compósitos de um Veículo Aéreo Não-Tripulado (VANT) de classe I para vigilância marítima. A intenção de expandir o uso de VANTs pela Força Aérea Portuguesa (FAP), na ampla área de jurisdição portuguesa e nas operações internacionais, motivou a necessidade de desenvolver uma nova plataforma capaz de cumprir todos os requisitos operacionais e tecnológicos. A presente tese começa pela definição dos sistemas a bordo necessários para a aeronave, nomeadamente a carga útil, aviónicos e propulsão. O design estrutural ao nível conceptual e preliminar envolveu o planeamento da disposição geral da aeronave para atingir uma margem estática longitudinal válida e a determinação do envelope de voo com rajada para determinar o factor de carga da aeronave. Este parâmetro vai definir a caracterização das forças aerodinâmicas e inérciais para a manobra crítica de voo. O projecto detalhado da aeronave foi realizado através de modelação em Desenho Assistido por Computador (CAD) com o objetivo de minimizer o peso estrutural. O design foi confirmado por uma análise numérica de tensões através de uma Análise de Elementos Finitos (FEA) e foi alcançada convergência para os valores obtidos de tensão e de deslocamento. O design desenvolvido é capaz de suportar a condição de carga crítica sem falha estrutural. A configuração da aeronave com todos os sistemas a bordo apresenta um peso dentro dos limites para a respectiva classe e uma autonomia de oito horas para operações de vigilância marítima. O design desenvolvido pode apresentar outras configurações, e tem uma autonomia máxima de doze horas.This thesis concerns the composite structural design of a class I Unmanned Aerial Vehicle (UAV) for maritime surveillance. The intention to expand the UAV use by Portuguese Air Force (FAP), over the broad area of Portuguese jurisdiction and in international operations, motivated the need to develop a new platform capable to fulfil all the operational and technological requirements. This thesis starts by defining all the necessary onboard systems for the aircraft, namely the payload, avionics and propulsion. The conceptual and preliminary structural design involved planning the general layout to achieve a valid longitudinal static margin and determining the aircraft flight envelope with gust loads to determine the design load. This design driver set the aerodynamic and inertial load characterization of the critical flight manoeuvre. The aircraft detailed design was performed through Computed Aided Design (CAD) modelling with the objective of minimizing the structural weight. The design was endorsed by a numerical stress analysis through a Finite Element Analysis (FEA) and achieved convergence for the stress and displacement results. The developed design withstands the critical load condition without failure of the structure. The aircraft configuration with full payload presents a weight within its class range and an endurance of eight hours for maritime surveillance operations. The implemented design supports other configurations, presenting an endurance up to twelve hours.N/

    Air Quality Monitoring, Assessment and Management

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    Human beings need to breathe oxygen diluted in certain quantity of inert gas for living. In the atmosphere, there is a gas mixture of, mainly, oxygen and nitrogen, in appropriate proportions. However, the air also contains other gases, vapours and aerosols that humans incorporate when breathing and whose composition and concentration vary spatially. Some of these are physiologically inert. Air pollution has become a problem of major concern in the last few decades as it has caused negative effects on human health, nature and properties. This book presents the results of research studies carried out by international researchers in seventeen chapters which can be grouped into two main sections: a) air quality monitoring and b) air quality assessment and management, and serves as a source of material for all those involved in the field, whether as a student, scientific researcher, industrialist, consultant, or government agency with responsibility in this area

    Investigating new accident causation, risk assessment, and mitigation strategy selection tools in the petroleum industry

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    The inherent complexity of the processes and the volatile nature of petroleum products compel the petroleum industry to continually seek and develop tools and techniques to identify, evaluate, and mitigate potential risks that can negatively impact their process operations. Additionally, government agencies and nonprofit professional societies guide the petroleum industry with regulatory guidelines, standards, and recommended best practices. The industry and these agencies and societies work to improve operational management, to ensure safe working conditions, and to minimize risk of all kinds, so that if failures occur, damage is contained within tolerable limits (Health and Safety Executives, 2013). The currently used of both qualitative and quantitative risk assessment tools fall short in identifying and ranking potential risks in the petroleum industry and they fail to demonstrate that risks have been reduced as low as reasonably practicable (ALARP) (Fitzgerald, 2004, p. 3). Moreover, the tools are limited to large, complex, and expensive studies (Fitzgerald, 2004, p. 3). Because accidents due to both human errors and electromechanical failures still occur and result in various consequences, critics have raised concerns about the petroleum industry\u27s safety and risk mitigation credentials and question its ability to prevent major accidents. The purpose of this research is to introduce new methods that provide more detailed and structure information to decision makers. They are more robust and easier-to-use so that novice engineers can successfully apply them without experts\u27 need. This dissertation employs the publication option, where the research results are reported by presenting the text of five journal-conference publications. --Abstract, page iv

    Layer-by-layer assembly of organic films and their application to multichannel surface plasmon resonance sensing

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    This thesis provides a study of a single chip, multi-channel surface plasmon resonance (SPR) imaging system. The equipment has no moving parts and uses a single sensor "chip" onto which multiple channels can be incorporated. A light emitting diode is used as a photon source while a CCD camera forms the detector. The optical configuration has been designed to achieve a uniform illumination of the sample over a fixed area with a range of incident angles. Poly(ethylene imine), PEI, poly(ethylene-co-maleic acid), PMAE, poly(styrene sulfonate), PSS, and a cationic modified polyacrylic ester, PMADAMBQ, are used as the molecular "bricks" in layer-by-layer (LbL) self-assembled organic architectures. Reflectivity changes in real time are used to follow the adsorption steps during the deposition of the multilayer films. Sensing experiments are mainly focused on the first row transition metals such as iron (II), nickel (II), copper (II)and zinc (II). Sensing of anionic sodium dodecylbenzene sulphate, C(_12)H(_25)C(_6)H(_4)SO(_3)Na, and a reversible pH-dependent response for a PEI/PMAE/PMADAMBQ LbL film are also reported. Using a two bilayer structure, PEI/PMAE/PMADAMBQ/PMAE, a detection limit of less of one part per million for copper ions in solution is measured. Atomic force microscopy is used to elucidate the morphology of the organic films. In some cases, the visualization of isolated polymeric chains is demonstrated. It is proved that polyelectrolytes of different charge density form dissimilar structures. The outer surface of PEI/PSS bilayers appears to be more uniform than that of PEI/PMAE bilayers. This is believed to have an influence on the sensing performance of the LbL architectures. The use of the SPR sensing system for simultaneous interrogation of different polyelectrolyte thin films is demonstrated. Two different LbL self-assembled films, PEI/PSS and PEI/PMAE, are built-up on the same chip. Their response to a variety of metal ions is shown to be independent and reasonably reproducible. Moreover, consistent results are obtained when using sensing chips stored for a relatively long time

    Multilayer Thin Films

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    This book, "Multilayer Thin Films-Versatile Applications for Materials Engineering", includes thirteen chapters related to the preparations, characterizations, and applications in the modern research of materials engineering. The evaluation of nanomaterials in the form of different shapes, sizes, and volumes needed for utilization in different kinds of gadgets and devices. Since the recently developed two-dimensional carbon materials are proving to be immensely important for new configurations in the miniature scale in the modern technology, it is imperative to innovate various atomic and molecular arrangements for the modifications of structural properties. Of late, graphene and graphene-related derivatives have been proven as the most versatile two-dimensional nanomaterials with superb mechanical, electrical, electronic, optical, and magnetic properties. To understand the in-depth technology, an effort has been made to explain the basics of nano dimensional materials. The importance of nano particles in various aspects of nano technology is clearly indicated. There is more than one chapter describing the use of nanomaterials as sensors. In this volume, an effort has been made to clarify the use of such materials from non-conductor to highly conducting species. It is expected that this book will be useful to the postgraduate and research students as this is a multidisciplinary subject

    ACADEMIC HANDBOOK (UNDERGRADUATE) COLLEGE OF ENGINEERING (CoE)

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    Multilayer Thin Films

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    This book, "Multilayer Thin Films-Versatile Applications for Materials Engineering", includes thirteen chapters related to the preparations, characterizations, and applications in the modern research of materials engineering. The evaluation of nanomaterials in the form of different shapes, sizes, and volumes needed for utilization in different kinds of gadgets and devices. Since the recently developed two-dimensional carbon materials are proving to be immensely important for new configurations in the miniature scale in the modern technology, it is imperative to innovate various atomic and molecular arrangements for the modifications of structural properties
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