Wheat grain cooking process as investigated by modulated temperature differential scanning calorimetry

The thermal properties of soft and hard wheat grains, cooked in a steam pressure cooker, as a function of cooking temperature and time were investigated by modulated temperature differential scanning calorimetry (MTDSC). Four cooking temperatures (110, 120, 130 and 140 degrees C) and six cooking times (20, 40, 60, 80, 100 and 120 min) for each temperature were studied. It was found that typical non-reversible heat flow thermograms of cooked and uncooked wheat grains consisted of two endothermic baseline shifts localised around 40-50 degrees C and then 60-70 degrees C. The second peaks of non-reversible heat flow thermograms (60-70 degrees C) were associated with starch gelatinisation. The degree of gelatinisation was quantified based on these peaks. In this study, starch was completely gelatinised within 60-80 min for cooking temperatures at 110-120 degrees C and within 20 min for cooking temperatures at 130-140 degrees C. MTDSC detected reversible endothermic baseline shifts in most samples, localised broadly around 48-67 degrees C with changes in heat capacity ranging from 0.02 to 0.06 J/g per degrees C. These reversible endothermic baseline shifts are related to the glass transition, which occurs during starch gelatinisation. Data on the specific heat capacity of the cooked wheat samples are provided. (C) 2005 Elsevier Ltd. All rights reserved.

Metagenomic analysis of two enhanced biological phosphorus removal (EBPR) sludge communities

Enhanced biological phosphorus removal (EBPR) is one of the best-studied microbially mediated industrial processes because of its ecological and economic relevance. Despite this, it is not well understood at the metabolic level. Here we present a metagenomic analysis of two lab-scale EBPR sludges dominated by the uncultured bacterium, Candidatus Accumulibacter phosphatis.'' The analysis sheds light on several controversies in EBPR metabolic models and provides hypotheses explaining the dominance of A. phosphatis in this habitat, its lifestyle outside EBPR and probable cultivation requirements. Comparison of the same species from different EBPR sludges highlights recent evolutionary dynamics in the A. phosphatis genome that could be linked to mechanisms for environmental adaptation. In spite of an apparent lack of phylogenetic overlap in the flanking communities of the two sludges studied, common functional themes were found, at least one of them complementary to the inferred metabolism of the dominant organism. The present study provides a much needed blueprint for a systems-level understanding of EBPR and illustrates that metagenomics enables detailed, often novel, insights into even well-studied biological systems.

Effect of extrusion parameters on flavour retention, functional and physical properties of mixtures of starch and D-limonene encapsulated in milk protein

The purpose of this research was to investigate the retention of flavour volatiles encapsulated in water-insoluble systems during high temperature–short time extrusion process. A protein precipitation method was used to produce water-insoluble capsules encapsulating limonene, and the capsules were added to the extruder feed material (cornstarch). A twin-screw extruder was used to evaluate the effect of capsule level of addition (0–5%), barrel temperature (125–145 °C) and screw speed (145–175 r.p.m.) on extruder parameters (torque, die pressure, specific mechanical energy, residence time distribution) and extrudate properties [flavour retention, texture, colour, density, expansion, water absorption index, water solubility index (WSI)]. Capsule level had a significant effect on extrusion conditions, flavour retention and extrudate physical properties. Flavour retention increased with the increase in capsule level from 0% to 2.5%, reached a maximum value at capsule level of 2.5% and decreased when the capsule level increased from 2.5% to 5%. The die pressure, torque, expansion ratio, hardness and WSI exhibited the opposite effect with the presence of capsules.

Gas-fired radiant heaters

This dissertation covers four areas of particular interest for the successful application of radiant heating in industrial environments. In it the author tackles the problem of how to predict the thermal comfort produced both by single heaters and also systems of heaters; proposes a method for modelling the mechanisms by which heaters interact with the buildings in which they are installed, in the static and dynamic cases; explores techniques for measuring the radiation produced by heaters; and presents experiments concerned with finding the temperatures and power balances prevailing during normal operation. It is contended that, whilst the generally accepted guides for sizing and operating space heating plant were a good first approximation, there are intrinsic subtleties arising from the fact that the primary mode of heat transfer in this instance is radiative. These nuances are concerned with how best to maximise the heat transfer from the heat source to the heated object; the placement of heaters within a system; and an assessment of the various techniques and strategies involved in controlling a radiant heating system. The conclusions reached are that: if sized and controlled correctly radiant heating systems offer considerable operational advantages over other types of space heating systems in certain applications, in terms of both economy and controllability. The efficacy of radiant heating systems is affected primarily by the control strategy implemented; secondarily, by the structure of the building into which it is installed; and only marginally by all other factors.

Innovative measurement methodology in the study of weathering of automotive coatings

An initial aim of this project was to evaluate the conventional techniques used in the analysis of newly prepared environmentally friendly water-borne automotive coatings and compare them with solvent-borne coatings having comparable formulations. The investigation was carried out on microtuned layers as well as on complete automotive multi-layer paint systems. Methods used included the very traditional methods of gloss and hardness and the commonly used photo-oxidation index (from FTIR spectral analysis). All methods enabled the durability to weathering of the automotive coatings to be initially investigated. However, a primary aim of this work was to develop methods for analysing the early stages of chemical and property changes in both the solvent-borne and water-borne coating systems that take place during outdoor natural weathering exposures and under accelerated artificial exposures. This was achieved by using dynamic mechanical analysis (DMA), in both tension mode on the microtomed films (on all depths of the coating systems from the uppermost clear-coat right down to the electron-coat) and bending mode of the full (unmicrotomed) systems, as well as MALDI-Tof analysis on the movement of the stabilisers in the full systems. Changes in glass transition temperature and relative cross-link density were determined after weathering and these were related to changes in the chemistries of the binder systems of the coatings after weathering. Concentration profiles of the UV-stabilisers (UVA and HALS) in the coating systems were analysed as a consequence of migration in the coating systems in separate microtomed layers of the paint samples (depth profiling) after weathering and diffusion co-efficient and solubility parameters were determined for the UV stabilisers in the coating systems. The methods developed were used to determine the various physical and chemical changes that take place during weathering of the different (water-borne and solvent-borne) systems (photoxidation). The solvent-borne formulations showed less changes after weathering (both natural and accelerated) than the corresponding water-borne formulations due to the lower level of cross-links in the binders of the water-borne systems. The silver systems examined were more durable than the blue systems due to the reflecting power of the aluminium and the lower temperature of the silver coatings.

Analysis of clogging in constructed wetlands using magnetic resonance

In this work we demonstrate the potential of permanent magnet based magnetic resonance sensors to monitor and assess the extent of pore clogging in water filtration systems. The performance of the sensor was tested on artificially clogged gravel substrates and on gravel bed samples from constructed wetlands used to treat wastewater. Data indicate that the spin lattice relaxation time is linearly related to the hydraulic conductivity in such systems. In addition, within biologically active filters we demonstrate the ability to determine the relative ratio of biomass to abiotic solids, a measurement which is not possible using alternative techniques. © 2011 The Royal Society of Chemistry.

Design and analysis of micro-channel heat-exchanger embedded in Low Temperature Co-fire Ceramic (LTCC)

Increased device density, switching speeds of integrated circuits and decrease in package size is placing new demands for high power thermal-management. The convectional method of forced air cooling with passive heat sink can handle heat fluxes up-to 3-5W/cm2; however current microprocessors are operating at levels of 100W/cm2, This demands the usage of novel thermal-management systems. In this work, water-cooling systems with active heat sink are embedded in the substrate. The research involved fabricating LTCC substrates of various configurations - an open-duct substrate, the second with thermal vias and the third with thermal vias and free-standing metal columns and metal foil. Thermal testing was performed experimentally and these results are compared with CFD results. An overall thermal resistance for the base substrate is demonstrated to be 3.4oC/W-cm2. Addition of thermal vias reduces the effective resistance of the system by 7times and further addition of free standing columns reduced it by 20times.

Sedimentology of a Middle Jurassic Base-of-Slope environment, Cutri Formation, Mallorca

The Cutri Formation’s, type location, exposed in the NW of Mallorca, Spain has previously been described by Álvaro et al., (1989) and further interpreted by Abbots (1989) unpublished PhD thesis as a base-of-slope carbonate apron. Incorporating new field and laboratory analysis this paper enhances this interpretation. From this analysis, it can be shown without reasonable doubt that the Cutri Formation was deposited in a carbonate base-of-slope environment on the palaeowindward side of a Mid-Jurassic Tethyan platform. Key evidence such as laterally extensive exposures, abundant deposits of calciturbidtes and debris flows amongst hemipelagic deposits strongly support this interpretation.

Exploring problem-framing through behavioural heuristics

Design for behaviour change aims to influence user behaviour, through design, for social or environmental benefit. Understanding and modelling human behaviour has thus come within the scope of designers’work, as in interaction design, service design and user experience design more generally. Diverse approaches to how to model users when seeking to influence behaviour can result in many possible strategies, but a major challenge for the field is matching appropriate design strategies to particular behaviours (Zachrisson & Boks, 2012). In this paper, we introduce and explore behavioural heuristics as a way of framing problem-solution pairs (Dorst & Cross, 2001) in terms of simple rules. These act as a ‘common language’ between insights from user research and design principles and techniques, and draw on ideas from human factors, behavioural economics, and decision research. We introduce the process via a case study on interaction with office heating systems, based on interviews with 16 people. This is followed by worked examples in the ‘other direction’, based on a workshop held at the Interaction ’12 conference, extracting heuristics from existing systems designed to influence user behaviour, to illustrate both ends of a possible design process using heuristics.

The Redox Potentials of n-type Colloidal Semiconductor Nanocrystals

Thesis (Ph.D.)--University of Washington, 2016-08

Avaliação da eficiência do sistema de abastecimento de água da APA

A água é um recurso essencial e escasso, como tal, é necessário encontrar medidas que permitam o seu uso de modo sustentável e garantam a proteção do meio ambiente. Devido a esta crescente preocupação assiste-se a um movimento legislativo, nacional e internacional, no sentido de garantir o desenvolvimento sustentável. Surge assim, a Diretiva Quadro da Água e a Lei da Água, que é complementada com legislação diversa. Como elemento constituinte do ciclo urbano da água, os Sistemas de Abastecimento têm sofrido evoluções nem sempre adequadas. É neste contexto que, em Portugal, nascem as diversas ferramentas para a melhoria da gestão dos recursos hídricos. As Entidades Gestoras têm como finalidade a gestão eficiente do bem água, e dispõe de dois importantes instrumentos, o Programa Nacional para o Uso Eficiente da Água e o Guia para o “controlo de perdas de água em sistemas públicos de adução e distribuição”(ERSAR). Esta Gestão passa, não só pela abordagem da problemática das perdas de água, reais e aparentes, como também pela análise do comportamento que origina o desperdício. A APA, enquanto entidade gestora, procura maximizar a eficiência do seu sistema de abastecimento, para tal, foram aplicadas as ferramentas propostas pelo ERSAR. Concluindo-se que este sistema tem um total de perdas de água de 34%, devendo-se estas perdas essencialmente ao envelhecido parque de contadores e perdas nos ramais de distribuição (teórico). As perdas comerciais representam cerca de 69%, o que revela que os volumes de água não faturados (medidos ou não) são muito elevados. Por outro lado, a realização do cálculo do Balanço Hídrico e dos índices de desempenho permitem classificar a performance do sistema de abastecimento e compará-la com os seus objetivos de gestão. Atendendo ao volume de água perdido nos ramais, foram efetuadas medições noturnas, verificando-se que no Porto de Pesca Costeira existe um volume de água escoado não justificado. Neste sentido, elaborou-se um plano de ação para aumentar a eficiência do sistema, ou seja, reduzir as perdas totais de 34% para 15%.

The FIREDASS (Fire Detection and Suppression Simulation) Model

The FIREDASS (FIRE Detection And Suppression Simulation) project is concerned with the development of fine water mist systems as a possible replacement for the halon fire suppression system currently used in aircraft cargo holds. The project is funded by the European Commission, under the BRITE EURAM programme. The FIREDASS consortium is made up of a combination of Industrial, Academic, Research and Regulatory partners. As part of this programme of work, a computational model has been developed to help engineers optimise the design of the water mist suppression system. This computational model is based on Computational Fluid Dynamics (CFD) and is composed of the following components: fire model; mist model; two-phase radiation model; suppression model and detector/activation model. The fire model - developed by the University of Greenwich - uses prescribed release rates for heat and gaseous combustion products to represent the fire load. Typical release rates have been determined through experimentation conducted by SINTEF. The mist model - developed by the University of Greenwich - is a Lagrangian particle tracking procedure that is fully coupled to both the gas phase and the radiation field. The radiation model - developed by the National Technical University of Athens - is described using a six-flux radiation model. The suppression model - developed by SINTEF and the University of Greenwich - is based on an extinguishment crietrion that relies on oxygen concentration and temperature. The detector/ activation model - developed by Cerberus - allows the configuration of many different detector and mist configurations to be tested within the computational model. These sub-models have been integrated by the University of Greenwich into the FIREDASS software package. The model has been validated using data from the SINTEF/GEC test campaigns and it has been found that the computational model gives good agreement with these experimental results. The best agreement is obtained at the ceiling which is where the detectors and misting nozzles would be located in a real system. In this paper the model is briefly described and some results from the validation of the fire and mist model are presented.

Microturbinas em redes de abastecimento de água

Nos dias de hoje a sociedade exige níveis qualitativos de vida cada vez mais elevados, o que torna prioritária a conceção de sistemas eficientes, não poluidores, económicos e diversificados que permitam uma gestão integrada e racionalizada de recursos tão escasso como é o da água e da energia. Em sistemas de abastecimento de água, o uso de válvulas redutoras de pressão (VRP) visa a uniformização e controlo de pressões, promovendo uma perda de carga localizada que dissipa a energia hidráulica presente através da redução dos valores de pressão a jusante. Estas são fundamentais no controlo e redução de pressão. A utilização de microturbinas é uma alternativa sustentável para o controle de pressão e, simultaneamente, para a produção de energia elétrica. Trata-se de um método de mitigação para controlar as perdas referidas convergindo no âmbito da eficiência energética. Na perspetiva de promover um aproveitamento de energia nas redes de abastecimento de água, o presente trabalho sugere a substituição de válvulas redutoras de pressão (VRP) por microturbinas. Desse modo, apresenta-se um método automático de seleção de (i) local para implementação e (ii) projeto de microturbinas para sistemas de abastecimento de água. Para a modelação do funcionamento dos sistemas hidráulicos recorre-se ao simulador hidráulico EPANET. Esta ferramenta possibilita avaliação de caudais e pressões em todos os pontos da rede durante um determinado intervalo de tempo. A metodologia desenvolvida permite selecionar o local ideal no sistema hidráulico através de uma análise de cada secção conduta-nó escolhendo-se a melhor opção baseada na produção de energia. Depois da localização procede-se à seleção do tipo de turbina (Kaplan, Francis, Pelton e Cross-flow) que vai depender das características do sistema hidráulico. Na etapa seguinte apresenta-se os resultados obtidos pela turbina nomeadamente a produção de energia elétrica anual, o investimento necessário, o tempo de retorno e a rentabilização ao final de um período de 25 anos. Na última etapa da metodologia, de forma avaliar o comportamento do sistema final, realiza-se uma nova simulação da rede mas tendo em conta a introdução da microturbina no local. Apresentam-se alguns casos de estudo que validam a ferramenta desenvolvida. A metodologia desenvolvida é comparada com um caso de estudo real. Em ambos os exemplos simulados a metodologia aplicada permite obter soluções com ganhos energéticos significativos associados ao sistema. Apenas num dos exemplos se observaram que a implementação da microturbina no sistema hidráulico não seria economicamente rentável.

Proposta de método para avaliação do desempenho térmico de residências unifamiliares em clima quente e úmido

Nowadays, evaluation methods to measure thermal performance of buildings have been developed in order to improve thermal comfort in buildings and reduce the use of energy with active cooling and heating systems. However, in developed countries, the criteria used in rating systems to asses the thermal and energy performance of buildings have demonstrated some limitations when applied to naturally ventilated building in tropical climates. The present research has as its main objective to propose a method to evaluate the thermal performance of low-rise residential buildings in warm humid climates, through computational simulation. The method was developed in order to conceive a suitable rating system for the athermal performance assessment of such buildings using as criteria the indoor air temperature and a thermal comfort adaptive model. The research made use of the software VisualDOE 4.1 in two simulations runs of a base case modeled for two basic types of occupancies: living room and bedroom. In the first simulation run, sensitive analyses were made to identify the variables with the higher impact over the cases´ thermal performance. Besides that, the results also allowed the formulation of design recommendations to warm humid climates toward an improvement on the thermal performance of residential building in similar situations. The results of the second simulation run was used to identify the named Thermal Performance Spectrum (TPS) of both occupancies types, which reflect the variations on the thermal performance considering the local climate, building typology, chosen construction material and studied occupancies. This analysis generates an index named IDTR Thermal Performance Resultant Index, which was configured as a thermal performance rating system. It correlates the thermal performance with the number of hours that the indoor air temperature was on each of the six thermal comfort bands pre-defined that received weights to measure the discomfort intensity. The use of this rating system showed to be appropriated when used in one of the simulated cases, presenting advantages in relation to other evaluation methods and becoming a tool for the understanding of building thermal behavior

Proposta de metodologia para certificação hídrica de edifícios residenciais

A presente dissertação tem como objetivo a elaboração de uma proposta de certificação hídrica para edifícios residenciais existentes e em fase de projeto. O desenvolvimento desta certificação incide essencialmente na poupança de água potável nos edifícios, demonstrando que o consumo excessivo da mesma poderá traduzir-se num problema no futuro. O uso eficiente da água assume cada vez mais uma importância acrescida. Neste trabalho enumeram-se alguns países da Europa que, devido a uma má gestão da sua água ou às alterações climáticas (como por exemplo, a diminuição da precipitação), se encontram ou poderão se encontrar em “stress hídrico”. É apresentado o Programa Nacional para o Uso Eficiente da Água, fazendo-se referência aos principais objetivos do programa e às medidas propostas para redução de consumos, nomeadamente no setor urbano e em particular ao nível dos sistemas prediais e dos dispositivos em instalações residenciais. Com base nisto, são apresentados consumos e potenciais reduções com a implantação de equipamentos hidricamente eficientes e sistemas de aproveitamento de águas em algumas moradias. Após uma análise de sistemas de certificação da construção sustentável existentes, nacionais e internacionais, é apresentada uma proposta de certificação hídrica de edifícios residenciais. A proposta de certificação é apresentada com recurso a folhas de cálculo Excel.Assenta essencialmente na quantificação dos consumos dos equipamentos sanitários e cálculo do contributo dos sistemas de aproveitamento de águas, sejam cinzentas ou pluviais. À semelhança da certificação energética, a proposta de certificação hídrica faz uma comparação dos consumos da habitação em avaliação com um modelo criado de referência, propondo depois, algumas melhorias que o consumidor pode adotar para melhorar a eficiência da sua residência.