Literatura científica selecionada sobre o tema "Ambient envelop-"

Double envelope vacuum insulation panels (VIPs) have a possibility to significantly increase the service lifetime. In this paper, double envelope VIPs were produced and installed in the residential house. The performance of installed VIPs was evaluated by using the measuring data of heat flux meter. In addition, the total energy, the heating load and the indoor thermal environment of this house were measured and analysed. The average heating load and the average temperature difference between room temperature and ambient air temperature on the representative day was 2.49 kW and 29.9 oC, respectively. The heat loss coefficient per floor area was estimated as 0.69 W/(m2K) and it was almost the same as the value calculated at the time of design. The result of indoor environment measurement showed that the room temperature was maintained at around 20 oC and PMV was -0.5 oC or higher although the outside air temperature fluctuated between -5 oC and -10 oC. The effective thermal conductivities of double envelop VIPs were all estimated as 0.01 W/(mK) or less. It is considered that the insulation performance of the vacuum insulation panels is maintained.

The hygrothermal transfer is very important for the design of a building envelope for thermal comfort, economic and energy analysis of the building envelope. The lack of reference materials on models of moisture and temperature behavior in the building, including wooden walls, is a challenge. This paper reviewed the hygrothermal transfer models for building walls. Energy and mass conservation equations with boundary and input conditions were presented in this paper for concrete, bricks, and wooden walls. The review showed the presence of mainly physical-based models, while there is a dearth of data-based models. The influence of the type of wall, orientation, thickness, the density of the material, and climatic variations on the temperature and moisture evolutions within the building materials influenced the model mechanisms. Future research gaps should include shrinkage influence on hygroscopic materials like wood due to their behavior under ambient conditions. Data-based models should be explored too.

A collection of results are presented which are loosely centered around the notion of reflective subcategory. For example, it is shown that reflective subcategories are orthogonality classes, that the morphisms orthogonal to a reflective subcategory are precisely the morphisms inverted under the reflector, and that each subcategory has a largest “envelope” in the ambient category in which it is reflective. Moreover, known results concerning the envelopes of the category of sober spaces, spectral spaces, and jacspectral spaces, respectively, are summarized and reproved. Finally, attention is focused on the envelopes of one-object subcategories, and examples are considered in the category of groups.

An aerostat is a tethered balloon with an aerodynamically shaped envelope containing a lighter-than-air gas that generates bulk of the lifting force. Aerostats are used extensively as an aerial platform for many scientific and commercial applications. Conventional aerostats envelopes have an ellipsoidal shape, due to which they suffer from a large amount of horizontal displacement (called blowby) due to the ambient winds. If the drag force acting on aerostat is high, the resulting blowbyis higher and a longer tether is required to maintain the specified operating altitude; this results in lower payload capacity. Recent studies have shown that winged aerostats (which have an envelope with airfoil cross-section) can reduce blowbydue to a much higher lift/drag ratio. This paper presents a comparative analysis of the operational effectiveness of a winged and conventional aerostat for scientific data gathering in lower Himalayas at various ambient wind speeds. The winged aerostat is seen to be much smaller in size, and has a much lower reduction in operating altitude due to blowby. The paper also describes the design of a prototype winged aerostat currently under development.

This work deals with the influence of envelope thickness and solar absorption on the time lag and the decrement factor. For this, a test cell of 1 m3 of volume is built with a material commonly used in construction in Senegal, the compressed earth brick stabilized with cement. The ambient-air temperature inside and outside of test cell and solar direct normal irradiance is measured. The test cell is modeled using EnergyPlus software. The comparison of experimental and theoretical ambient-air temperature puts out a great linear showing the reliability of the model. The time lag and the decrement factor are calculated using the air-sol equivalent temperature of the test cell and the inside ambient-air temperature. The time lag and decrement factor of the compressed stabilized earth brick envelope are respectively 0.22 and 6.6 h showing the good thermal inertia of those bricks. A parametric study is performed to determine the effect of envelope thickness and solar absorptivity on the time lag and decrement factor. The results show that the decrement factor decreases with envelope thickness while the time lag increases linearly and that an envelope thickness of 32 cm has a decrement factor of around zero with a maximum time lag of about 12 h for this type of material. The envelope’s solar absorption has a moderate effect on the decrement factor and time lag.

Small rotary compressors are used in domestic heat pump appliances, for example, in domestic dehumidifiers and heat pump clothes dryers. Compressor performance curves provided by the manufacturer can be based on testing at relatively high ambient temperatures, in some cases as high as 35∘C. This can be much higher compared with the ambient temperature in which the compressor operates when, for example, it is installed in a domestic dehumidifier which can operate in ambient temperatures as low as 10∘C. We have developed a compressor calorimeter to test a small R134a rotary compressor extracted from a commercial domestic dehumidifier and use this to measure compressor performance parameters including the isentropic and volumetric efficiencies and the compressor heat loss fraction. The performance testing has been carried out at ambient temperatures 10∘C, 15∘C, 20∘C and 25∘C for a fixed relative humidity of 70% to compare how the compressor performance varies with the ambient temperature, and to determine how well the compressor performs outside of the performance envelope provided by the manufacturer. The results show that isentropic and volumetric efficiency of these small compressors is relatively insensitive to variation in ambient temperature, even outside of the performance envelope provided by the manufacturer. However, the compressor heat loss fraction can, on average, double from 15% to 30%, between operation at ambient 25∘C and ambient 10∘C. The data obtained in this work is used to construct compressor sub-models for certain ambient temperatures. We show how these sub-models can be used to improve a domestic dehumidifier model for operation at low ambient conditions within the evaporator frosting regime and good agreement is obtained between experimental and simulated data. The authors are not aware of a domestic dehumidifier model designed to work at ambient temperatures within the frosting regime.

Cette thèse déploie son analyse à partir de la présence de l’enfant dans les configurations variées de l’espace public urbain. Elle privilégie une lecture des ambiances pour appréhender la manière dont le corps des enfants est mobilisé par son environnement. L’étude s’attache ainsi à adopter une analyse dynamique de la façon dont l'enfant s'insère, s'émeut et s'adapte au sein de l’espace public. Le concept d’affordance établi par le psychologue James J. Gibson occupe une place centrale dans cette étude (Gibson, 1979). Il permet de déployer une lecture des propriétés du bâti en ce qu’elles stimulent, offrent ou « appellent » certaines activités. Parmi celles-ci, le jeu, librement choisi, contribue au développement global de l’enfant.Notre approche se confronte à une littérature scientifique dense et variée qui a examiné l’impact du jeu en extérieur sur le comportement et le développement de l’enfant. Au tournant des années 1970, il semble que la libre présence des enfants dans l’espace public urbain tende à se restreindre et à poser la question de l’émergence de systèmes de surveillance corrélée à l’idée d’une vulnérabilité de l’enfant dans la ville. Non sans liens, les infrastructures et environnements de jeu, qui apparaissent d’abords insuffisants, se développent pour configurer dans l’espace urbain des îlots séparés formant des aires de jeu créées par les adultes. Cette thèse envisage de repartir du corps en mouvement de l’enfant pour envisager son champ de perception et, plus loin, son rapport à la ville (Breviglieri, 2014). L’approche écologique et sensible aux ambiances permettra de poser un regard expérimental et évaluatif sur les espaces urbains présents dans le quotidien des enfants.La thèse interroge une variété de designs d’espaces (résidentiels ou proprement ludiques) de la ville dans son lien aux comportements de jeu des enfants. Pour cela, elle propose d’investiguer quatre environnements urbains hétérogènes en Égypte et en France. L’étude des dimensions récréatives et résidentielles prend alors appui sur une « approche de recherche par enquête comparative causale » et des « études de cas intrinsèque » (Groat & Wang, 2013).Cette enquête de terrain est menée en trois phases, avec des enfants « d’âge moyen» choisis au hasard, entre cinq et douze ans. Elle comprend des observations comportementales structurées centrées sur le comportement de l’enfant. Ces observationssont complétées par une étude des activités cognitives perceptuelles engagée dans l’effectuation de dessins et de photographies, et par la réalisation d’entretiens informels associés occasionnellement à des parcours commentés. Les données recueillies ont été analysées dans le cadre de la « théorie du triptyque de l'espace » et de la « théorie des affordances ». Ce cadre a pour objet de clarifier les écarts de perception et de représentation entre celles qui appartiennent au concepteur de l’environnement urbain et celles qui appartiennent à l’enfant dans son expérience physique et culturelle de l’espace. Il est possible d’extraire de cette étude des thèmes capables de renouveler certaines orientations de la fabrique de la ville. Ces thèmes convergent pour repenser à la fois la place de l’enfant dans la ville, et la manière dont celle-ci peut générer des environnements intergénérationnels favorisant le bien-être des citadins.« Une ville où l’enfant serait le prince et le père de l’homme » (Aillaud, 1972)
Play is a freely chosen process that is important for the overall children development. A relatively large amount of research efforts have investigated the impact of play, particularly outdoor play in natural environments, on children's play behavior and the consequent impact on their development. However, in the recent decades, modern societies have noticed an intense declination of play opportunities in outdoor spaces especially in the local everyday community urban spaces, as living streets, neighborhoods, and recreational public spaces, due to the imposed structured activities, adult supervision, and poor playing environments such as enclosed playgrounds.To date, relatively few studies have investigated children's lived experiences in their daily urban spaces, where they can play freely. Although they have their own way of perceiving, experiencing, and living the daily urban spaces, different from adults that results in creating a gap. Thus, in order to fill in the resulted gap, this study aims to investigate the potential impact of the urban transformation of daily urban spaces on children presence and their play behavioral patterns. The second objective is to explore the associations between specific spatial physical characteristics as well as functional qualities, or “spatial potentialities” that form different configurations, and children play opportunities (Breviglieri, 2014(.The study relies on a “causal comparative survey research approach” and an “intrinsic case study” (Groat & Wang, 2013). It involves the investigation of four selected urban spaces, with different spatial configuration, (recreational and residential urban functional categories), in Paris, France and Cairo, Egypt. Fieldwork is conducted through three phases, with randomly selected “middle-aged” children, between 5 to 12 years. It included structured child-centered behavioral observations complemented with behavioral qualitative observations, perceptual cognitive skill activities as drawings as well as photography, and informal interviews associated occasionally with child- led walks.Collected data is analyzed within the shadow of both “Trialectic of Space Theory” (Lefebvre, 1992) and “Affordances theories”, (Gibson, 1979, Norman 1988, Bohme, 2017), to fill in the problematic gap. This created gap is situated between the designed spaces by adult so as designers, children perceptions depending on their capabilities, cultural, social background, as well as their previous experience, and the resulted lived space with its specific ambiance adopting children’s needs and behaviors.The study strongly suggests that spatial porosity of daily urban spaces, influence children's presence and the occurrence of different play behavior types. In addition, different spatial typologies seemed to promote different play patterns that may enhance different children’s spatial perceptions and preferences. Moreover, the study identified and outlined a set of specific spatial potentialities aspects, forming different spatial configurations, which appeared to be associated to children's sensory experiences, play opportunities, and the resulted lived ambient envelop.This study tended to enable urban planners and landscape architects to extract the essential characteristics that help creating child-friendly spaces. In order to encompass children with diversity of cultures and origins from all over the world. Hereafter, it will open a new perspective in the design, by proposing a design approach and guidelines to articulate children's spaces in the city; it is not a question of thinking of these spaces, as closed islands, but rather as child-friendly environments within intergenerational cities.“A city where the child would be the prince and the father of Man” (Aillaud, 1972)

Esta tesis se plantea, como objetivo principal, definir un modelo de evaluación de los impactos ambientales vinculados a la envolvente de los edificios, para poder asignarles una valoración mediante indicadores de sostenibilidad reconocidos. Estos indicadores podrían incrementar la información que los catálogos aportan al diseñador en la selección de soluciones constructivas. Así mismo, con este modelo de evaluación, se pretende contribuir al desarrollo de una herramienta, de aplicación en España, que apoye al diseñador, para que éste pueda valorar el comportamiento medioambiental de las diferentes alternativas en la fase inicial del diseño. El diseñador dispone mediante el análisis de ciclo de vida (ACV) de una metodología que le permite evaluar los impactos ambientales del edificio en las primeras etapas del diseño, pero su aplicación requiere mucho tiempo y una cualificación que normalmente resulta incompatible con sus condiciones de trabajo. Además, para poder valorar las diferentes opciones, el diseñador no solo precisa conocer todos los impactos considerados en función de las múltiples variables; sino que necesita poder comparar los diferentes valores entre sí. Y para ello, lo ideal es disponer de esta información antes de seleccionar una opción u otra, es decir, antes de realizar su proyecto. La metodología planteada en esta tesis se basa en la aplicación de un ACV simplificado a un caso de estudio considerando diferentes combinaciones de la envolvente, diferentes orientaciones del edificio y distintas zonas climáticas para calcular los indicadores ambientales, previamente seleccionados, en todas las fases del ciclo de vida del edificio. Para proceder a la selección de los indicadores, ha resultado necesario establecer claramente los objetivos de sostenibilidad y determinar cuáles son los criterios de selección a utilizar. La información obtenida al evaluar múltiples opciones de la envolvente es cuantificable y ha permitido disponer de suficientes datos estadísticos para la construcción de los indicadores ambientales basándose en un sistema de regresión múltiple. A partir del valor asignado a cada uno de los indicadores en las diferentes fases del ciclo de vida del edificio, el proyectista puede disponer de información medioambiental en tiempo real de cada solución constructiva en la fase inicial del diseño. Los impactos se han calculado en función de la proporción geométrica de los elementos que integran cada solución constructiva, lo que permite al diseñador adaptar los datos para la obtención de resultados según su proyecto. El modelo definido ha permitido asignar valores a los indicadores desarrollados: emisiones de CO2, consumo de energía, consumo de agua potable, residuos generados peligrosos y no peligrosos y costes de inversión, mantenimiento y uso. Estos resultados, una vez ponderados se han plasmado en una matriz de Excel. La herramienta permite modificar los parámetros implicados a fin de efectuar estudios de sostenibilidad y extraer conclusiones.
The aim of this thesis is to define an evaluation model of environmental impacts of building envelopes, which allows to estimate scientifically recognized sustainability indicators for different assemblies. These indicators will increase the information that existing catalogues show to support designers in the selection of constructive assemblies. Additionally, this evaluation model is aimed to be useful for the development of a future tool which allows designers to evaluate the environmental behavior of different alternatives from the initial phases of design. Life Cycle Analysis (LCA) represents a means to evaluate the environmental impacts of buildings in the early stages of design, but its use requires much time and a qualification that normally turns out to be incompatible with designers’ work conditions. In addition, to be able to evaluate the different alternatives, designers not only need to investigate all the possible impacts depending on the multiple variables; but it is also necessary to compare the different results between them. This implies that this information should ideally be at disposal of designers before they embark upon the development of their projects. The methodology developed in this thesis is based on a simplified LCA which is applied to a case of study considering different envelope assemblies, building orientations and climatic zones. Environmental indicators are calculated for the envelope assemblies, considering all the phases of the building life cycle. A previous selection of environmental indicators was made for which it was necessary to clearly establish the aims of sustainability and determine a set of selection criteria. The evaluation of the different envelope assemblies produced enough numerical data for statistical treatment, and the environmental indicators model was built based on a system of multiple regressions. From the value assigned to each of the indicators in the different phases of the building life cycle, designers dispose of environmental real time information of every constructive assembly from the initial phases of design. Impacts are calculated depending on the geometry of the different elements that constitute each constructive assembly; what allows designers to obtain project-related results by simply providing geometric information for the different materials involved. The defined model allowed to determine values for the developed indicators: CO2 emissions; energy consumption; consumption of drinking water; hazardous and nonhazardous waste; and investment, maintenance and use costs. These results, once weighted, were plot in an Excel matrix. The tool allows the modification of parameters in order to conduct studies and draw conclusions.

Dissertação de Mestrado em Energia para a Sustentabilidade apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra
As alterações climáticas representam atualmente um dos maiores desafios ambientais para qualquer empresa. As variações climáticas e os eventos extremos podem afetar a atividade comercial; no entanto, este setor contribui para essas alterações climáticas, uma vez que todas as operações inerentes à transação de produtos pressupõem o consumo de energia e combustíveis para transportes, para além de emissões de gases com efeito de estufa. O presente trabalho foi realizado no contexto de um estágio efetuado na Direção Conceção Loja da Sonae MC e tem como objetivo dar resposta ao desafio lançado, que se centrou na questão “Como potenciar o desenvolvimento do Supermercado Sustentável do Futuro?”. Com uma perspetiva abrangente, no âmbito das soluções arquitetónicas dos edifícios de supermercados, pretende-se explorar materiais e soluções construtivas sustentáveis, minimizando o impacto no ambiente e comunidade. Em resposta a este desafio, e depois de detetado um conjunto de pontos-chave ao longo da análise aos projetos desenvolvidos pela equipa de acolhimento, propõem-se formas de mitigação do impacto ambiental e de otimização da eficiência energética dos edifícios, abordando critérios arquitectónicos como a orientação dos edifícios, iluminação e ventilação naturais, materiais de construção e ainda a área exterior envolvente ao edifício. Dentro do conjunto de propostas, a análise das características do comportamento térmico da envolvente dos edifícios assume particular importância, por representar o maior impacto na redução dos consumos energéticos das lojas. Centrando-se na envolvente opaca em contacto com o exterior, pretendeu-se estabelecer um termo comparativo entre várias soluções de tipo e espessura de isolamento térmico, de forma a perceber qual a solução ótima para cada loja. Criou-se, pois, uma folha de cálculo denominada de U-SUPER, cujo propósito é o de se constituir como ferramenta de apoio aos projetos futuros da equipa, de forma intuitiva, no que concerne ao cálculo do coeficiente de transmissão térmica, perdas energéticas pela envolvente e custos anuais em energia para diversas soluções construtivas. A adoção das recomendações apresentadas propõe-se melhorar o desempenho ambiental dos edifícios de supermercados, contribuindo assim para a assunção da sustentabilidade ambiental como uma responsabilidade social da empresa.
Climate change currently represents one of the greatest environmental challenges for any company. Climate variability and extreme events can affect commercial activity; however, this sector helps these climate changes, since all operations related to the sale of products require the consumption of energy and transport fuels, as well as emissions of greenhouse gases. This work was done in the context of an internship made in Store Concept in Sonae MC, the greatest Portuguese retail company. It aims to respond to the challenge focused on the question “How to boost the development of the Sustainable Supermarket of the Future?”. With a comprehensive perspective, in the context of architectural solutions of supermarket buildings, it is intended to explore materials and sustainable building solutions, minimizing the impact on the environment and community. In response to this challenge, and after detect a set of key points throughout the analysis to projects developed by the team, it is proposed several ways to mitigate the environmental impact and maximizing energy efficiency of buildings with an architectural approach, such as orientation of buildings, natural lighting and ventilation, building materials and landscape. Within the set of proposals, analysis of the thermal behaviour of the buildings envelope is particularly important, since it represents the greatest impact on reducing energy consumption in stores. Focusing on opaque envelope in contact with the outside, it was intended to establish a comparison between various solutions of type and thickness of thermal insulation, in order to find out the optimal solution for each store. It was created a worksheet called U-SUPER, whose purpose is to provide a tool to assist team’s future projects, intuitively, in regard to the calculation of the heat transfer coefficient, energy losses and annual energy costs for various constructive solutions. The adoption of the proposals presented intends to improve the environmental performance of supermarket buildings, thus contributing to the assumption of environmental sustainability as a corporate social responsibility.

Tese de doutoramento em Sistemas Sustentáveis de Energia, apresentada ao Departamento de Energia Mecânica da Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Residential buildings are accountable for a significant share of final energy consumption and environmental impacts. Although new houses are expected to hold significantly lower impact than existing dwellings, Portuguese building regulations and most actions at building level still focus mainly on operational energy reduction, disregarding building embodied impacts. Aiming to transition to more sustainable new building practices, a life cycle (LC) perspective is needed and has been advocated by LC studies of dwellings. Generally LC studies of new houses acknowledge the importance of building construction options, the envelope thermal performance, and energy systems, which jointly characterize the embodied and the operational impacts. But new houses in south Europe and Portugal have seldom been addressed from a LC perspective, and the few existing LC studies fail to consider that, in mild Mediterranean climate, the operational impact (for heating and cooling) may be highly dependent on user behavior. Additionally architectural design options have not been addressed from a LC perspective. This thesis goal is to assess the influence of alternative building envelope, design, and operational conditions on the environmental impact of new single-family houses in Portugal considering alternative user behavior. A framework combining life cycle assessment (LCA) and building dynamic simulation was developed and implemented to investigate how operational and embodied impacts of Portuguese single family houses vary among options at different levels: building envelope (insulation thickness, ventilation level, building components), design (orientation, window sizing and placement, and building shape), and operation (user operational pattern, heating systems selection, electricity generation mix). Insulation thickness tipping points that reduce the house LC impact were identified for different Portuguese locations. The results showed that embodied energy of new houses (construction and maintenance) can represent two to seven times the operational heating and cooling energy (operational pattern OP50, with heat pump or wood pellets boiler, respectively) for most locations (Coimbra, Lisboa, Porto and Faro). Even under more demanding Portuguese weather conditions (e.g., Évora, Bragança) embodied impacts are likely to surpass operational impact due to user behavior (OP25-OP50, using a heat pump system). Therefore, careful attention should be paid to building design and building components selection. Comparative results showed that design options can have a higher influence in the overall impact of new houses than changing the envelope insulation or ventilation levels. Additionally selecting building components with lower embodied impact and similar thermal performance (e.g., wooden exterior wall instead of a double brick wall) can have a higher influence on reducing overall impacts than focusing only on envelope thermal improvement. Results also showed that the LC impact of new Portuguese dwellings is very sensitive to operational conditions, namely operational patterns and the heating system selected. But, based on the potentially small contribution of thermal energy requirements, current building regulations might miss important LC impacts when focusing only on operational energy, especially for new houses in Portugal, and in other south European locations with mild Mediterranean climate.
Os edifícios de habitação são responsáveis por uma parte significativa do consumo energético e dos impactes ambientais. Embora se espere que os novos edifícios de habitação tenham um impacte ambiental significativamente menor do que os edifícios existentes, em Portugal, a regulamentação existente e a maioria das ações são focadas principalmente no desempenho térmico do edifício e na fase de utilização, não tendo em conta os impactes ambientais incorporados no próprio edifício (na sua construção e manutenção). Para apoiar a conceção de edifícios de habitação com menor impacte ambiental, é importante considerar uma perspetiva de ciclo de vida (CV), a qual tem sido defendida por estudos de CV de edifícios. Em geral, os estudos CV de novos edifícios habitacionais identificam as opções construtivas, o desempenho térmico da envolvente, e os sistemas energéticos, como opções relevantes que influenciam os impactes incorporados no edifício e os impactes da fase de utilização. No entanto, apenas alguns estudos de CV abordam edifícios de habitação em Portugal, e os poucos estudos existentes para novos edifícios não consideram que, em clima Mediterrânico moderado, os impactes ambientais da fase de utilização podem ser significativamente dependentes do comportamento dos habitantes. Adicionalmente, os estudos existentes não consideram opções de desenho arquitetónico numa perspetiva de ciclo de vida. O objetivo desta tese é avaliar a influência de diferentes opções construtivas da envolvente do edifício, do desenho arquitetónico, e das condições operacionais no impacto ambiental de moradias unifamiliares em Portugal considerando diferentes padrões de utilização. Um modelo de CV que combina a metodologia de Avaliação de Ciclo de Vida (ACV) com a simulação dinâmica de edifícios foi desenvolvido para analisar como variam os impactes ambientais incorporados e os impactes ambientais da fase de utilização de uma moradia unifamiliar em Portugal, considerando diferentes opções construtivas da envolvente (nível de isolamento térmico, nível de ventilação, e paredes exteriores), alternativas arquitetónicas (orientação, tamanho e localização dos vão envidraçados, e forma do edifício), e condições operacionais (padrão de utilização, sistemas de climatização e mix energético). Com base no modelo desenvolvido foram identificados níveis de espessura do isolamento térmico que reduzem o impacte ambiental de ciclo de vida da moradia para diferentes localizações em Portugal. Os resultados da ACV mostraram que a energia incorporada em edifícios de habitação unifamiliar (construção e manutenção) pode representar duas a sete vezes a energia operacional de climatização (padrão operacional OP50, com bomba de calor ou caldeira a pellets, respetivamente) para a maioria das localizações (Coimbra, Lisboa, Porto e Faro). Mesmo sob condições climáticas mais exigentes (por exemplo, Évora ou Bragança), é provável que os impactes incorporados ultrapassem o impacte operacional graças aos padrões de utilização (OP50-OP25, e um sistema de bomba de calor). Por conseguinte, deve ser dada especial atenção ao desenho arquitetónico e à seleção dos elementos construtivos. Os resultados mostraram que, em moradias novas, as opções arquitetónicas podem ter uma maior influência no impacte ambiental do que alterar o nível de isolamento térmico da envolvente ou o nível de ventilação. Adicionalmente, a seleção de componentes de construção com menor impacte ambiental incorporado e com desempenho térmico semelhante (por exemplo, uma parede exterior de madeira em vez de uma parede de tijolo dupla) pode ter uma maior influência na redução de impacte ambiental global do que focar apenas na melhoria do desempenho térmico da envolvente. Os resultados mostraram também que o impacte ambiental de ciclo de vida de novas moradias em Portugal é muito sensível às condições operacionais, nomeadamente aos padrões de utilização e ao sistema de aquecimento selecionado. Mas, com base na potencialmente pequena contribuição das necessidades de aquecimento e arrefecimento, os regulamentos de construção atuais que se focam na energia operacional, não contabilizam uma parte significativa do impacte ambiental de ciclo de vida, especialmente para novas moradias em Portugal e em outros locais do sul da Europa com clima mediterrâneo moderado.
SABIOS - (Sustainability assessment of bioenergy systems: a life-cycle multi-criteria decision-support approach, including land use change) FEDER/FCT | PTDC/AAG-MAA/6234/2014 (POCI-01-0145-FEDER-016765)

AbstractThe South African Lowveld is a region of land that lies between 150 and 2000 m above sea level. In summer the region is characterized by the maximum mean daily ambient temperature of 32 °C. The purpose of the study was to characterize indoor thermal environments in low-cost residential dwellings during summer seasons as climate is changing. Indoor and ambient air temperature measurements were performed at a 30-min temporal resolution using Thermochron iButtons in the settlement of Agincourt. 58 free running low-cost residential dwellings were sampled over the summer seasons of 2016 and 2017. Complementary ambient air temperature data were sourced from the South African Weather Service (SAWS). Data were transformed into hourly means for further analysis. It was found that hourly maximum mean indoor temperatures ranged between 27 °C (daytime) and 23 °C (nighttime) for both living rooms and bedrooms in summer 2016 while in 2017, maximum mean indoor temperatures ranged between 29 °C (daytime) and 26 °C (nighttime) in living rooms and bedrooms. Pearson correlations showed a positive association between indoor and ambient temperatures ranging between r = 0.40 (daytime) and r = 0.90 (nighttime). The association is weak to moderate during daytime because occupants apply other ventilation practices that reduce the relationship between indoor and ambient temperatures. The close association between nighttime ambient and indoor temperature can also be attributed to the effect of urban heat island as nighttime ambient temperature remain elevated; thus, influencing indoor temperatures also remain high. These findings highlight the potential threat posed by a rise in temperatures for low-cost residential dwellings occupants due to climate change. Furthermore, the high level of sensitiveness of dwellings to ambient temperature changes also indicates housing envelopes that have poor thermal resistance to withstand the Lowveld region’s harsh extreme heat conditions, especially during summer. The study findings suggest that a potential risk of indoor overheating exists in low-cost dwellings on the South African Lowveld as the frequency and intensity of heat waves rise. There is therefore a need to develop immediate housing adaptation interventions that mitigate against the projected ambient temperature rise for example through thermal insulation retrofits on the existing housing stock and passive housing designs for new housing stock.

One of the most pressing problems of textualism is the “noise aesthetics” of the increasingly complex acoustic ecologies of modern cinema. In order to develop a narrative theoretical framework capable of integrating “noise”—understood as “insignificant” sounds that define the ambience or acoustic ecology of the diegesis—this chapter employs the notion of the soundscape to enrich our understanding of narrative space beyond its textual confinement as the container of the characters and events. Spurred by the rich sound ecologies of contemporary cinema, this chapter provides a revaluation of narrative space as a dynamic agency that implies the recipients’ material, bodily, sensorimotor, and affective engagements. Essential thus becomes the immediacy of the mediated environment. To capture this paradox at the heart of the cinematic experience, it is argued that the notion of the soundscape should be given analytical precedence over the diegetic/nondiegetic binary that has long inhibited scholars from understanding cineacoustics as more than an accompaniment to the fictional world of the film. As part of the film’s overall affective assemblage, the notion of the soundscape can be employed to understand the narrative rhetoric of films that communicate through “insignificant” noises. As an example of this, this chapter examines the use of “sonic envelopes” and “noise aesthetics” in A Quiet Place (directed by Krasinski 2018) to conclude that cinematic signification cannot be reduced to its “literal” denotations but emerges on the basis of a resonance effect. Cinematic signification thus requires the embodied spectator to partake of the film’s orchestrated flows of movements.

Because aircraft gas turbine operates under various flight conditions that changes with altitude, flight velocity and ambient temperature, performance estimation that considers the flight conditions must be known before developing or operating the gas turbine. More so, for the UAV (Unmanned Aerial Vehicle) where the engine is activated by an onboard engine controller in emergency, the precise performance model including the estimated steady-state and transient performance data should be provided to the engine control system and the engine health monitoring system. In this study, a GUI (Graphic User Interface) type steady-state and transient performance simulation model of the PW206C turbo shaft engine that was adopted for use on the Smart UAV was developed using SIMULINK for performance analysis. For the simulation model, firstly the component maps including compressor, gas generator turbine and power turbine were inversely generated from manufacturer’s limited performance deck data by Hybrid Method. For the work and mass flow matching between components of the steady-state simulation, the state-flow library of SIMULINK was applied. The proposed steady-state performance model can simulate off-design point performance at various flight conditions and part loads, and in order to evaluate the steady-state performance model their simulation results were compared with manufacturer’s performance deck data. According to comparison results, it was confirm that the steady-state model well agreed with the deck data within 3% in all flight envelop. In the transient performance simulation model, the CMF (Continuity of Mass Flow) method was used and the rotational speed change was calculated by integrating the excess torque due to the transient fuel flow change using Runge-Kutta method. In this transient performance simulation, the turbine overshoot was predicted.

Building lighter and thinner has conceptually targeted the reduction of energy and labor in processes of construction and material production. However, this thinning does not always mean a reduction in energy use as shown by the expenditure of energy required to control a thin envelope’s ambient sequestration or the production of the preferred materials for the thin envelope. Despite these considerations, architectural production has evolved from thick enclosures to thin solutions. The pattern that is predicated on minimum material envelopes and energy-dependent standardized ambient conditioning requirements has produced an energy-hungry building stock. Reversing the typical constructive paradigm from thinness to thickness poses reversals of norms, with the potential to manage carbon emissions through production, maintenance, and conditioning. The preferred ratio of thin enclosure and large interior volume is redefined in favor of a performative thick boundary layer and a less energy-hungry interior. Terra Cotta Grotto proposes a return to mass in architecture, rede¬fined through the contemporary lens of thermodynamic and ambient processes that, at certain scales, dematerializes the very solid boundary layer and provokes a critical discussion around how thickness can redefine our carbon footprint.

A aplicação dos materiais frios na envoltória é uma técnica passiva que pode contribuir na eficiência energética de edificações. A fim de avaliar o desempenho térmico de tintas frias nacionais, mediu-se a refletância solar em laboratório e a temperatura superficial de amostras expostas ao Sol. Os resultados indicaram diferenças significativas de refletância para tintas de mesma cor, porém com menor variação de temperatura entre elas. Contudo, a reflexão no infravermelho próximo mostrou-se mais relevante para reduzir a absorção de calor nas superfícies, comprovando-se a importância da obtenção de dados medidos em laboratório para a escolha adequada de revestimentos para edifícios.

Na construção civil, a escolha das cores que constituirão o envelope construtivo muitas vezes são determinadas seguindo apenas fatores estéticos. Porém, em decorrência da propriedade superficial dos materiais de absortância solar, as cores das edificações também influenciam o desempenho térmico das mesmas. O objetivo principal deste trabalho foi analisar os impactos do envelhecimento natural em telhas cerâmicas e de concreto, sobre suas características de parâmetros de cor e temperatura superficial; ambos associados à variação de absortância solar. Para isso, 25 telhas foram selecionadas e expostas às intempéries, por um período de 24 meses, em uma estação de envelhecimento natural, localizada na cidade de São Carlos, SP. Verificou-se que o parâmetro de cor com maior correlação em relação à absortância solar (αsolar) é a luminosidade (L*), e que, de forma geral, quanto maior a luminosidade (L*), menor é a absortância solar (αsolar) da telha. Além disso, altos valores de absortâncias solares (αsolar), implicam em baixos valores de luminosidade (L*), o que de certa forma explica a associação visual, muitas vezes equivocada, entre as cores “claras” e sua baixa absorção de radiação solar. A telha com maior luminosidade (L*) e menor absortância solar iniciais (αsolar) foi a amostra que sofreu maior variação percentual de absortância solar ao final da exposição. No entanto, apesar de ter sido a amostra mais impactada pela degradação natural, esta continuou apresentando as menores temperaturas superficiais dentre todas as amostras selecionadas, mesmo após os 24 meses de intemperismo. Portanto, pode-se concluir que nem sempre a amostra com menor degradação percentual ao longo do tempo é mais recomendada quando se pensa em conforto térmico nas edificações. Em relação às cores, não foi possível determinar uma linha de tendência para as alterações dos parâmetros a*, b*, C e h ao longo de 24 meses de exposição ao tempo, para as 25 telhas selecionadas neste trabalho. Por fim, conclui-se que a correta especificação das cores e o controle das propriedades ópticas dos materiais do envelope construtivo é uma estratégia de baixo custo e eficiente para se controlar os ganhos térmicos de uma edificação.

A compreensão do comportamento dos materiais que compõem o envelope construtivo em relação ao ganho térmico é de extrema importância. Nesse sentido, este trabalho analisa o desempenho térmico pela metodologia de simulação da ABNT NBR 15.575/2013 de uma habitação unifamiliar térrea, localizada na cidade de Curitiba/PR, inserida na Zona Bioclimática Brasileira 1 (ZB1). A análise compara os resultados de desempenho térmico de cinco combinações diferentes de valores de absortância da cobertura, através do software EnergyPlus 8.7, da interface gráfica Sketchup 2017 e do plugin Euclid 0.9.3. Com este estudo, observou-se que a absortância solar das telhas de cobertura apresenta influência significativa no aumento da carga térmica interna. Em relação à análise do desempenho térmico, apenas um dos valores de absortância não obteve condições de temperaturas internas aceitáveis. No entanto, salienta-se que, no verão, até mesmo o caso que apresentou uma temperatura interna de 30,4°C, passou nos critérios da norma e, no inverno, os níveis de desempenho foram facilmente atingidos, uma vez que a temperatura mínima foi extrema de 3,9°C.

Economic and regulatory requirements have transformed today’s power plant operations. High reserve margins and increased fuel costs have driven combined cycle plants that were once dispatched primarily at base-load to be cycled off during off-peak hours. For many plants, the increased cycling has contributed to shorter maintenance intervals and higher overall operating costs. Technology advancements in combustion system design and in gas turbine control systems has led to extensions in the emissions-compliant operating window of gas turbines, also known as turndown. With extended turndown capability, customers are now able to significantly reduce fuel consumption during minimum load operation at off-peak hours, while simultaneously minimizing the number of shutdowns. Extended turndown reduces operational costs by offsetting the fuel consumption costs against the costs associated with starting up and the maintenance costs associated with such starts. Along with the increased emphasis on turndown capability, there has been a rising need to develop and standardize methods by which turndown capability can be accurately measured and reported. By definition, the limiting factor for turndown is the exhaust gas emissions, primarily CO and NOx. A concurrent and accurate measurement of performance and emissions is an essential ingredient to the determination of turndown capability. Of particular challenge is the method by which turndown results that were measured at one set of ambient conditions can be accurately projected to a specific guarantee condition, or to a range of ambient conditions, for which turndown capabilities have been guaranteed. The turndown projection methodology needs to consider combustion physics, control system algorithms, and basic cycle thermodynamics. Recent advances in the integration of empirically tuned physics-based combustion models with control system models and the gas turbine thermodynamic simulation, has resulted in test procedures for use in the contractual demonstration of turndown capability. A discussion of these methods is presented, along with data showing the extent to which the methods have provided accurate and repeatable test results.

O baixo desempenho termoenergético das edificações está diretamente relacionado a um inadequado planejamento arquitetônico. No caso de edificações escolares, a padronização do projeto pode gerar uma problemática ainda maior e não apenas relacionada ao seu desempenho energético. Com metodologias que combinam simulação computacional e motores de otimização, é possível que se identifique possíveis parâmetros de melhoria do desempenho desses edifícios através de um ou mais objetivos, como no caso das soluções multiobjetivas. Neste estudo, será apresentada a análise do desempenho de uma estratégia de otimização multiobjetivo, com alteração dos parâmetros de transmitância térmica das paredes externas, do piso e da cobertura, assim como, a orientação solar da edificação e as absortâncias das paredes externas e da cobertura. Esse recorte corresponde a parte inicial de uma pesquisa que visa a definição de medidas de adaptação do envelope térmico do projeto-padrão Proinfância tipo 2, para implantação na zona bioclimática 2. Na análise de resultadas foi possível observar um princípio de convergência em direção ao ponto ótimo já entre as primeiras gerações do algoritmo, onde os melhores casos foram constatados. Além disso, também foram identificadas questões de aperfeiçoamento da técnica de otimização, para que resultados ainda mais eficientes sejam futuramente alcançados.

A presença de umidade nos materiais da envoltória da edificação pode alterar as características internas de conforto e consumo de energia elétrica dos ambientes internos. O estudo sobre umidade é fundamental para o correto dimensionamento dos sistemas de condicionamento de ar e para estimativas de consumo de energia elétrica mais precisas. Assim sendo, esse artigo tem como objetivo apresentar o consumo de desumidificação de uma edificação com elevado nível de isolamento térmico no envelope, comparando 7 estratégias de desumidificação. A análise foi desenvolvida com o uso da ferramenta Passive House Planning Package (PHPP), com uma edificação atendendo os requisitos da certificação Standard Passive House, a partir da definição de diversos cenários de análise os quais poderiam diminuir o consumo de energia de desumidificação. Os cenários analisados foram ventilação mecânica noturna, abertura noturna de janelas, e variação da vazão da ventilação noturna. Em relação aos resultados, as menores vazões testadas, as quais possibilitam a manutenção da qualidade do ar interior, obtiveram os melhores resultados em termos de consumo de resfriamento, envolvendo calor sensível e calor latente. Outro aspecto que ficou evidente nas simulações é o peso do processo de desumidificação no contexto geral do consumo de energia de climatização artificial no período de verão, a desumidificação impactou em 54,3% o consumo total de resfriamento, destacando a importância do calor latente no contexto total.

Abstract In this paper, the thermal performances of a Chiplet module with different numbers of dies were studied. The Chiplet module was assumed to be placed in the same server system, with the same ambient condition, and using the same heat sink. A thermal simulation was conducted to obtain the junction temperatures of dies using different power magnitudes. With the change of power magnitudes of the dies, a thermal resistor matrix was calculated. Finally, with the calculation of the thermal resistor matrix, a unique power envelope plot was developed to determine if the power magnitudes of the chips on the Chiplet module caused any reliability concern. A risk factor was calculated to determine if the power magnitude of the die is within the safe region. With risk factors, we will be able to quantify the differences of applied powers with respect to the maximum allowed limits. We have expanded the usage of the power envelope plots to the Chiplet modules having more than three dies. The power envelope plots are a good tool for designers to optimize the power magnitudes, especially at the early stage of the Chiplet module design.

Offshore pipelines installed in moderate to deep water depths (1,500 ft. and beyond) must, by necessity, be designed to withstand ambient external pressure. Improper design can lead to catastrophic collapse of large sections of the structure. During the installation process the line can experience significant bending and tension loads in addition to external pressure. These additional loads can significantly reduce the collapse pressure of the pipe. Special purpose combined loading test facilities were designed and built in which pressures equivalent to 10,000 ft. and beyond were simulated. The test facilities were used to establish load interaction collapse envelopes for the two types of combined loading mentioned. Bending/pressure collapse envelopes were generated for tubes with diameter to thickness ratios of 34.7, 24.5, 18.2 and 17.3. Tension/pressure collapse envelopes were generated for tubes with diameter to thickness ratios of 38.3, 24.5, 18.2 and 12.2. The geometric imperfections and material parameters were recorded for all test specimen's prior to collapse. Under bending/pressure loading the tube response, the critical collapse loads and the nature of the instabilities observed were found to depend on the loading path. Collapse was found to be relatively insensitive to the history for tension/pressure loading.

In response to ozone and nitrogen dioxide (NO2) National Ambient Air Quality Standards (NAAQS), it is anticipated that there will be continued pressure for retrofit NOx control of existing slow speed integral reciprocating engines. This will likely require the retrofit of many additional legacy lean burn pipeline engines over the next decade, and emissions controls will require compliance verification which has been historically based on periodic emission tests. However, agencies also desire continuous "monitoring" of an operating parameter or parameters indicative of engine status. This document describes a method for ensuring a reciprocating engine with emission controls is operating properly. Continuous engine performance monitoring (CEPM) using on-engine sensors can provide early identification of potential engine operational issues, while also assuring the engine is operating within an acceptable operating envelope consistent with acceptable emissions performance. CEPM can reduce maintenance and compliance costs. This report provides the foundation for lower cost compliance assurance using CEPM.