Journal articles on the topic 'Dwellings Thermal properties'
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1
Zhang, Tao, Jia Ping Liu, Jun Wang, and Qi Wei Zhang. "Evaluation for Climates Adaptive Capability of Traditional Tuzhang Dwelling." Advanced Materials Research 450-451 (January 2012): 1219–22. http://dx.doi.org/10.4028/www.scientific.net/amr.450-451.1219.
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Present study is concentrated on evaluating the climate adaptive capability of Tuzhang dwellings. The comparisons to different thermal physical properties such as thermal resistance R0, thermal inertia index data D, reduction coefficient of thermal wave transferring V0 and thermal transferring delaying time ξ0 have been performed between Tuzhang dwelling and normal brick house. Comparing results show that Tuzhang dwelling has much better thermal properties than normal brick house. Therefore, regarding to climate adaptive capability, traditional Tuzhang dwelling is vastly superior to brick house.
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Luo, Zhixing, and Yiqing Lu. "Multi-case study on the carbon emissions of the ecological dwellings in cold regions of China over the whole life cycle." Energy Exploration & Exploitation 38, no. 5 (July 2, 2020): 1998–2018. http://dx.doi.org/10.1177/0144598720934054.
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This study employed the bottom-up life cycle assessment method, examining the life cycle carbon emissions of three dwellings constructed at different times with different techniques in Yinchuan City, China, i.e. traditional earth brick dwelling (Case 1), brick–straw bale dwelling (Case 2), wood–straw solar energy dwelling (Case 3). The study aimed to find the methods of reducing carbon emissions, so as to slow down the global warming. The results showed that (1) with excellent thermal insulation properties, straw bale was remarkably effective in reducing carbon emissions from heating at the use stage; (2) 15 kWp solar photovoltaic panels contributed to offsetting the carbon emission of the dwelling; (3) straw bales and logs could store the carbon in building envelope, which partly offset the carbon emissions. The findings of this study have proved that ecological building materials and solar photovoltaic system have great potential in reducing carbon emissions of buildings, and can provide a basis for the design and material selection of future dwellings in order to promote the development of green dwellings.
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Rodríguez Jara, Enrique Ángel, Álvaro Ruiz-Pardo, Marta Conde García, and José Antonio Tenorio Ríos. "Effect of Wood Properties and Building Construction on Thermal Performance of Radiant Floor Heating Worldwide." Applied Sciences 12, no. 11 (May 27, 2022): 5427. http://dx.doi.org/10.3390/app12115427.
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Due to its relatively lower thermal conductivity, the suitability of wood is called into question when selecting the flooring material best suited to radiant heating systems. The European standard EN 1264 considers floorings with a thermal resistance over 0.15 m2 K/W to be out of scope. This belief was partially disproved in a previous article that studied wooden floors for Madrid’s climate. However, the effect of climate still needs to be addressed. The present study extends the previous research to worldwide climates and aimed to answer the following questions: (1) Do the lowest thermal conductivity woods present good thermal performance when used in radiant floors? (2) Should the flooring have a maximum thermal resistance value? (3) Is the standard thermal resistance limit of 0.15 m2 K/W objectively justified? And (4) Do the answers of the preceding questions depend on the climate and the construction characteristics? To answer these questions, 28 cities were selected according to the Köppen–Geiger climate classification. In each city, 216 different dwellings were simulated with 60 wood floorings and one of low thermal resistance as a reference, comprising a total of 368,928 cases. Thermal performance was evaluated in terms of three parameters: energy demand, thermal comfort, and start-up lag time. Consequently, the answers to the previous questions were: (1) The lowest thermal conductivity woods can be used efficiently worldwide in radiant floor heating systems with start-up lag times close to that of the reference flooring; (2) There is no limit value for thermal resistance for floorings that can be applied to all dwellings and climates; (3) No objective justification was found for establishing a thermal resistance limit for flooring of 0.15 m2 K/W; and (4) Climate and construction characteristics can play an important role in the correct selection of flooring properties, especially in severe winters and dwellings with the greatest outdoor-exposed envelope and the worst insulation.
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Du, Shu Ting, Jin Zhu Ma, and Dong Wang. "Experimental Research on Thermal and Mechanical Properties of Modified Rammed Earth Material." Advanced Materials Research 450-451 (January 2012): 773–77. http://dx.doi.org/10.4028/www.scientific.net/amr.450-451.773.
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Taking the mix proportion of rammed earth dwellings in Anji as the basic standard, the physical properties, thermal properties, mechanical properties of rammed earth in various mix proportion have been tested by means of experiments. The results showed that the proportion of hydrated lime added to the rammed earth have a direct influence on the thermal conductivity, specific heat, compressive strength and shear strength of rammed earth specimens, the thermal and mechanical properties of modified rammed earth material is better when hydrated lime in the proportion of 10%～20%.
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Ruiz-Pardo, Álvaro, Enrique Ángel Rodríguez Jara, Marta Conde García, and José Antonio Tenorio Ríos. "Influence of Wood Properties and Building Construction on Energy Demand, Thermal Comfort and Start-Up Lag Time of Radiant Floor Heating Systems." Applied Sciences 12, no. 5 (February 23, 2022): 2335. http://dx.doi.org/10.3390/app12052335.
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Radiant floor heating is becoming increasingly popular in cold climates because it delivers higher comfort levels more efficiently than conventional systems. Wood is one of the surface coverings most frequently used in radiant flooring, despite the widely held belief that in terms of thermal performance it is no match for higher conductivity materials if a high energy performance is intended. Given that the highest admissible thermal resistance for flooring finishes or coverings is generally accepted to be 0.15 m2K/W, wood would appear to be a scantly appropriate choice. Nonetheless, the evaluation of the thermal performance of wooden radiant floor heating systems in conjunction with the building in terms of energy demand, thermal comfort, and start-up period, has been insufficiently explored in research. This has led to the present knowledge gap around its potential to deliver lower energy consumption and higher thermal comfort than high-thermal-conductivity materials, depending on building characteristics. This article studies the thermal performance of wood radiant floors in terms of three parameters: energy demand, thermal comfort, and start-up lag time, analysing the effect of wood properties in conjunction with building construction on each. An experimentally validated radiant floor model was coupled to a simplified building thermal model to simulate the performance of 60 wood coverings and one reference granite covering in 216 urban dwellings differing in construction features. The average energy demand was observed to be lower in the wood than in the granite coverings in 25% of the dwellings simulated. Similarly, on average, wood lagged behind granite in thermal comfort by less than 1 h/day in 50% of the dwellings. The energy demand was minimised in a significant 18% and thermal comfort maximised in 14% of the simulations at the lowest thermal conductivity value. The vast majority of the wooden floors lengthened the start-up lag time relative to granite in only 30 min or less in all the dwellings. Wood flooring with the highest thermal resistance (even over the 0.15 m2K/W cited in standard EN 1264-2) did not significantly affect the energy demand or thermal comfort. On average, wood flooring lowered energy demand by 6.4% and daily hours of thermal comfort by a mere 1.6% relative to granite coverings. The findings showed that wood-finished flooring may deliver comparable or, in some cases, higher thermal performance than high-conductivity material coverings, even when their thermal resistance is over 0.15 m2K/W. The suggestion is that the aforementioned value, presently deemed the maximum admissible thermal resistance, may need to be revised.
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FRANQUELO SOLER, JUAN, ELIDIA BEATRIZ BLÁZQUEZ PARRA, OSCAR DE COZAR MACIAS, MANUEL DAMIAN MARIN GRANADOS, and FRANCISCO JAVIER SOTO VILLARAN. "LOW-VELOCITY AIR INFILTRATION IN BUILDINGS, DISPLACEMENT DIFFUSION AND EFFECTS ON THERMAL EFFICIENCY AND COMFORT: A CASE STUDY." DYNA ENERGIA Y SOSTENIBILIDAD 11, no. 1 (May 2, 2022): [12P.]. http://dx.doi.org/10.6036/es10448.
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ABSTRACT: In 1979, the Spanish government implemented the standard “Basic Building on Thermal Conditions in Buildings NBE-CT-79”. It was then that the first requirements regarding insulation and thermal properties of materials were established to reduce energy consumption. The Mediterranean climate has influenced that insufficient attention has been paid to building insulation. In dwellings before 1979, it was detected that there is a feeling of lack of comfort. However, it is not so well known that there is a lack of airtightness in these dwellings, which may contribute to discomfort. The aim of the article is to find out if the air that enters spontaneously by infiltration produces effects similar to those of a displacement diffuser and how it affects thermal comfort. Thus, cold air would flow down the walls and be evenly distributed on the floor in winter, creating a homogeneous layer and feeling discomfort. Air infiltration measurements were carried out in 5 dwellings with an anemometer and infrared thermography to support the initial hypothesis. The Fanger Method, provided by the Polytechnic University of Valencia, was used to determine the thermal sensation produced. It was found that the cold air descended slowly and continuously to the ground in a similar way to a displacement diffuser, remaining for hours and being influential in the thermal conditions of the rooms and the lack of comfort of its occupants. Keywords: air infiltration, discomfort, thermography, displacement difusión, energy efficiency.
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Flores-Alés, Vicente, Alexis Pérez-Fargallo, Jesús A. Pulido Arcas, and Carlos Rubio-Bellido. "Effect on the Thermal Properties of Mortar Blocks by Using Recycled Glass and Its Application for Social Dwellings." Energies 13, no. 21 (October 31, 2020): 5702. http://dx.doi.org/10.3390/en13215702.
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Including recycled waste material in cement mixes, as substitutes for natural aggregates, has resulted in diverse research projects, normally focused on mechanical capacities. In the case of recycled glass as an aggregate, this provides a noticeable improvement in thermal properties, depending on its dosage. This idea raises possible construction solutions that reduce the environmental impact and improves thermal behavior. For this research, an extended building typology that is susceptible to experiencing the risk of energy poverty has been chosen. The typology is typical for social housing, built using mortar blocks with crushed glass. First, the basic thermophysical properties of the mortars were determined by laboratory tests; after that, the dynamic thermal properties of representative constructive solutions using these mortars were simulated in seven representative climate zones in Chile. An analysis methodology based on periodic thermal transmittance, adaptive comfort levels and energy demand was run for the 21 proposed models. In addition, the results show that thermal comfort hours increases significantly in thermal zones 1, 2, 3 and 6; from 23 h up to 199 h during a year. It is in these zones where the distance with respect to the neutral temperature of the m50 solution reduces that of the m25 solution by half; i.e., in zone 1, from −429 °C with the m25 solution to −864 °C with the m50. This research intends to be a starting point to generate an analysis methodology for construction solutions in the built environment, from the point of view of thermal comfort.
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Santana, Bruno Oliveira, Jefferson Torres-Quezada, Helena Coch, and Antonio Isalgue. "Monitoring and Calculation Study in Mediterranean Residential Spaces: Thermal Performance Comparison for the Winter Season." Buildings 12, no. 3 (March 9, 2022): 325. http://dx.doi.org/10.3390/buildings12030325.
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In cold regions, the reduction in envelope thermal transmittance is often the dominant parameter in ensuring thermal comfort in buildings. However, countries in warmer climates have also adopted this same strategy, often neglecting other parameters that are more influential in their respective climate regions that can achieve thermal comfort. This study focuses on passive building strategies to ensure a building’s thermal comfort conditions in Mediterranean climates in the winter. This monitoring study compares two dwellings during the winter in Barcelona, Spain, in order to analyze the impact of not only the envelope’s thermal properties on indoor temperature, but also the role of other factors such as outdoor temperature and solar gains. The dwellings were built in different decades, each following distinct building technical codes, diverse construction techniques, and building materials. The methodology used in this study is based on thermal measurements, meteorological data, and spreadsheet calculations. Comparing these results with the recent updates in Spain’s technical code and other studies, the investigation demonstrates that to achieve a suitable indoor thermal temperature in a passive way, especially in Mediterranean climates, incorporating other factors such as the combination of thermal inertia and solar gains can be more effective than a strategy mainly focused on reducing thermal transmittance. This analysis demonstrates that a building’s thermal performance does not mainly depend on envelope thermal transmittance, but rather a complex system involving a set of variables such as thermal inertia as well as solar gains, based on parameters such as building orientation and urban context.
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Lakatos, Ákos, István Csarnovics, and Attila Csík. "Systematic Analysis of Micro-Fiber Thermal Insulations from a Thermal Properties Point of View." Applied Sciences 11, no. 11 (May 27, 2021): 4943. http://dx.doi.org/10.3390/app11114943.
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In the European Union, almost 40% of all energy consumption comes from buildings, while another 20–25% comes from transport. In the European Union, including Hungary, only buildings with almost-zero energy demand could be built after 2020, and the use of renewable energies must be strengthened. The Renewable Directive stipulated that by 2020, the share of renewable energy in buildings must be 25%, and in transport it must be 10%; the use of electric vehicles is vital. There are about four million dwellings in Hungary, of which approximately three million need to be renovated, and only some of these (a few hundred) meet the cost-optimized level of the 2020 directive. The use of insulation materials is very important in the transport sector, too. Insulation materials are also used by aircraft and electric vehicles. To reduce the energy loss from buildings, different insulation materials can be used; investigations of insulation materials are very important. This paper presents a comprehensive research report on insulation materials which could be used for building elements, HVAC (heating, ventilation, and air conditioning appliances) equipment, and vehicles. In this paper, laboratory investigations will be presented along with calculations to better understand the properties and behavior of these materials. For this, firstly structural analysis with scanning electron microscope will be presented. Moreover, the paper will present thermal conductivity and combustion heat measurement results. The sorption and hydrophobic behavior of the materials will be also revealed. Finally, the article will also display differential scanning calorimetry measurements and Raman spectroscopy results of the samples. The research was conducted on four different types of colorized microfiber lightweight wool insulation.
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Zakriya, G. Mohamed, G. Ramakrishnan, T. Palani Rajan, and D. Abinaya. "Study of thermal properties of jute and hollow conjugated polyester fibre reinforced non-woven composite." Journal of Industrial Textiles 46, no. 6 (July 28, 2016): 1393–411. http://dx.doi.org/10.1177/1528083715624258.
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Sandwich structure of non-woven composite is produced by using a compressive hot pressing method. It is ranging from 2500 grams per square meter (gsm) to 3500 gsm. Composite sample is designed using Box and Behnken model. Considering 50–70% weight of jute fibre content with 30–50% weight of hollow conjugated polyester fibre, ideal thickness of the composites is maintained in the range from 4 to 5 mm. Thermal properties such as thermal conductivity, thermal resistance, thermal transmittance and thermal diffusivity were evaluated by considering three factors: weight of jute (A), weight of hollow conjugated polyester (B) and thickness of the composite (C). The thermal conductivity of the composite material is determined by heat flow meter method ASTM C518. Experiment result will help to make a suitable standardized panel composite for thermal insulation. It requires 3600 gsm 51/49 parts of contribution of jute/hollow conjugated polyester fibre with 5.0 mm thickness and 3200 gsm 76.5/23.5 parts of contribution of jute/hollow conjugated polyester fibre with 4.5 mm thickness of the composites. The composite weight of 3280 gsm shown optimized thermal responses, it was predicted from response surface method graph. Contribution of jute/hollow conjugated polyester fibre of 54/46 parts with 5.0 mm thickness would be considered to make standardized composite panel. Mostly air conditioning process reduces the energy cost spent for the thermal stability in indoor climate of dwellings.
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Cui, Hai Hong. "Research on Amending the Energy Efficiency Provisions in the Building." Applied Mechanics and Materials 568-570 (June 2014): 1991–94. http://dx.doi.org/10.4028/www.scientific.net/amm.568-570.1991.
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The purpose of this paper is to identify the main requirements of the Building Regulations Part L1A for new dwellings. An explanation of the technical basis for energy rating is given including how they are calculated, how fuel costs are used, the role of the standard occupancy pattern, and an appreciation of the Building Research Establishment Domestic Energy Model (BREDEM). The aims and requirements of the European Directive on the Energy performance of Buildings and its implementation for new and existing domestic buildings is also considered. Design/methodology/approach – The requirements of Part L1A of the Building Regulations are developed. These relate to the thermal properties of the building fabric including insulation, thermal bridging, air tightness and glazing, the efficiency and responsiveness of heating and hot water systems, ventilation and lighting. The methodology for calculating thermal transmittance coefficients (U-values) is also demonstrated.
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Perez-Bezos, Silvia, Anna Figueroa-Lopez, Matxalen Etxebarria-Mallea, Xabat Oregi, and Rufino Javier Hernandez-Minguillon. "Assessment of Social Housing Energy and Thermal Performance in Relation to Occupants’ Behaviour and COVID-19 Influence—A Case Study in the Basque Country, Spain." Sustainability 14, no. 9 (May 6, 2022): 5594. http://dx.doi.org/10.3390/su14095594.
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Evidence shows that people have a major impact on building performance. Occupants’ impact is especially important in social housing, where their occupants may present greater vulnerabilities, and their needs are not always considered. This study aims to analyse the socio-demographic influence in social rental housing concerning hygrothermal comfort and energy consumption in a case study located in Vitoria, Spain during the first 4-month period of 2020 and 2021 (during and after COVID-19 lockdown). An innovative data management system is included, where the users and administration can see in real-time the temperature and consumption in the dwellings. A 2-phase method has been applied; phase 1 is associated with outdoor climate conditions, building properties and social profile. Phase 2 determined the results in energy consumption, indoor hygrothermal comfort and occupant energy-use pattern. The results show that the comfort levels and energy consumption vary according to the analysed social profiles, as well as the heating activation periods and domestic hot water system usage. In conclusion, socio-demographic characteristics of social housing households influence the hygrothermal comfort of their dwellings, occupants’ behaviour and heating and domestic hot water energy consumption.
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Ferreira, Camila Carvalho, Henor Artur de Souza, and Joyce Correna Carlo. "Variables of influence on thermal performance of buildings under transient conditions." PARC Pesquisa em Arquitetura e Construção 12 (August 28, 2021): e021023. http://dx.doi.org/10.20396/parc.v12i00.8661655.
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Residential buildings significantly increase electricity demand, especially in developing countries. In this case, the requirements addressed by the standards can ensure the climatic adequacy of the envelope, enhance thermal performance, and promote thermal comfort conditions while reducing energy consumption. However, the criteria for evaluating the thermal performance of a building’s envelope that is commonly adopted in energy performance standards and codes have proved to be inefficient in hot climates. The heat exchanges within buildings are dependent on solar radiation and ventilation. The purpose of this article is to establish the variables with the greatest influence on the thermal performance of naturally ventilated dwellings in hot climates (equatorial, tropical and subtropical). For this investigation, a factorial design was adopted for sensitivity analysis. The structure of the factorial experiment defined the simulations of four patterns of single-family and multifamily residential buildings. We varied the thermophysical properties of the external walls and roofs, the heat gain coefficient of the openings, and natural ventilation. Brazil was adopted as a basis for climate analysis, including equatorial, tropical and subtropical climates. The analyses were based on comfort hours in an adaptive model and statistically evaluated using Analysis of Variance (ANOVA) tests. In general, the absorption of the walls and cover, the thermal transmittance of the cover and the natural ventilation were the variables of greatest influence on thermal comfort in a hot climate.
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Kalair, Ali Raza, Mehdi Seyedmahmoudian, Muhammad Shoaib Saleem, Naeem Abas, Shoaib Rauf, and Alex Stojcevski. "A Comparative Thermal Performance Assessment of Various Solar Collectors for Domestic Water Heating." International Journal of Photoenergy 2022 (June 16, 2022): 1–17. http://dx.doi.org/10.1155/2022/9536772.
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Growing population, depleting fossil fuels, economic expansions, and energy intensive life style demand are resulting in higher energy prices. We use energy as of heat and electricity, which can directly be obtained from sun using thermal collectors and solar cells. Solar thermal systems are gaining attention for water and space heating applications due to green aspects of solar energy. A solar thermal collector is a vital part of solar thermal energy system to absorb radiant energy from the sun. In this study, a solar water heating (SWH) system has been designed and simulated in the TRNSYS ® software using thermal and chemical properties of heat transfer fluids using REFPROP for dwellings located on ±31° latitudes (+31 Lahore in Pakistan and -31° Perth in Australia). We present an efficiency parametric optimization-based model for water and space heating. Simulation results for four types of solar thermal collectors are presented, and performance is analyzed on the basis of output temperature ( T out ), solar fraction ( f ), and collector efficiency ( η ). This study evaluates the comparative performance of evacuated tube collector (ETC), flat-plate collector (FPC), compound parabolic concentrator (CPC), and thermosiphon-driven systems. Our findings conclude the evacuated glass tube collector achieves the highest solar fraction, i.e., 50% of demand coverage during August in Pakistan and February in Australia, with an overall average of 43% annually.
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Mokhtari, Flora, Tohid Hatami Khanghahi, and Bahram Gosili. "Comparative Analysis on Thermal Properties of Traditional and Present-Age Rural Dwellings' External Walls Located in Submontane Regions of Mazandaran Province." Journal of Architectural Engineering 27, no. 1 (March 2021): 05020012. http://dx.doi.org/10.1061/(asce)ae.1943-5568.0000450.
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Whitman, Christopher J. "Heritage Earth Construction and Hygrothermal Comfort: The Challenge of Rebuilding in Central Chile." Key Engineering Materials 600 (March 2014): 186–95. http://dx.doi.org/10.4028/www.scientific.net/kem.600.186.
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According to the latest official census of 2002, earth construction represented 5.5% of the Chilean building stock. These buildings of traditional construction techniques of unfired earth and straw blocks (adobe), rammed earth (tapial) or wattle and daub (quincha) form a large proportion of Chile’s National Monuments and heritage buildings. In addition to their heritage value, these buildings with their high thermal mass, respond well to the climate conditions of both the altiplano of northern Chile and the Central Valley, zones with high diurnal temperature oscillations, with typical daily temperature differences of up to 20°C. However following the 2005 earthquake in Tarapacá, northern Chile and that of the 27th February 2010 in Central Chile a serious rethink has been required as to the retention and restoration of adobe buildings. Public opinion has labelled earth construction as unsafe and most reconstruction to date has taken place with prefabricated timber solutions which lack the necessary thermal mass to respond well to the climatic conditions. At the same time research into the structural integrity, seismic resistance, maintenance and the living conditions provided by earth construction has been undertaken. In this wider context this paper presents the compilation of international and Chilean research into the hygrothermal properties of adobe construction, in addition to the authors insitu measurements of the temperature and relative humidity in two surviving adobe dwellings in the earthquake hit village of Chépica located in Chile´s Central valley. These measurements are compared with those of a dwelling rebuilt with straw bales and earth render in the same location. Based on this information the paper studies the challenge of rebuilding and restoring heritage buildings whilst providing occupants with the necessary levels of environmental comfort.
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Berbouche, Chafia, Leila Sriti, and Sihem Latreche. "Vernacular Features in Rural Housing of the Aurassien massif between Traditional Practices and Bioclimatic Aspect. Case study of Ain Zaatout (Algeria)." Technium Social Sciences Journal 39 (January 8, 2023): 730–41. http://dx.doi.org/10.47577/tssj.v39i1.8281.
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The rural habitat in the Aures region is an excellent example on vernacular and human architecture. It reflects how inhabitants of this region responded to their requirements in an ingenious way and how local builders have succeeded to respond to challenges of climate, building materials and cultural expectations despite the particularly harsh environmental conditions of the Aures. The aim of this study is to determine the strategies used in vernacular constructions to deal with the severe climatic conditions that prevail in the Aures region. Precisely, rural dwellings in Ain Zaatout village (Beni Ferah) were studied to emphasize the importance of the architectural properties of the traditional houses in terms of thermal performance and climatic adaptability. In this regard, an extensive literature review was carried out on previous studies that investigated the Aures settlements. Accordingly, a comprehensive knowledge on typical Aurassien village and various data including spatial organisation, architectural characteristics and construction materials and techniques have been gathered. Based on this background, a qualitative analysis supported by field measurements was conducted. Then, two representative houses were selected as case studies for monitoring comfort parameters in summer period. Finally, the traditional and contemporary houses were compared in terms of their thermal performance. Through this study, the most frequently used strategies and their effectiveness were derived. The results indicate that vernacular rural habitat in the Aurassien villages is creatively adapted to the environmental conditions and uses various climate responsive strategies. The study additionally reveals that vernacular constructions in the Aures are more adapted to the climate constraints and social needs than contemporary residential buildings. These results were confirmed by hydrothermal values where main indoor temperature in a traditional rural house was less than external values by 3 °C and more humidified, while in modern house indoor temperature records were more than the exterior by 1°C. Thus, vernacular climatic responsive strategies must be considered as a reference for nowadays environmental issues in rural areas. Moreover, they can be feasible for contemporary buildings and, consequently, they could contribute greatly towards improving indoor thermal comfort whilst reducing buildings energy demand.
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Peebo, Alo, and Madis Rennu. "Maakivi ehitusmaterjalina: töötlemine ja kasutus." Studia Vernacula 4 (November 5, 2013): 73–86. http://dx.doi.org/10.12697/sv.2013.4.73-86.
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Fieldstone has been used as a building material for many centuries. In Estonia, two large groups of stone suitable for building can be distinguished in terms of architectural outcome and construction technique: calcareous stones (mostly carbonate flagstone and dolomite) and granite boulders, or field stones. The latter cover a broad spectrum of natural igneous and metamorphic rocks (rapakivi granite, diabases, gneiss etc.). In this article, we focus on natural stone belonging to the second group: in particular how it can be processed – split with wedges or a sledgehammer – and historical means of transporting stones. We also take a look at the ethical, aesthetic and cultural aspects of fieldstone use.Field stones were carried to Estonia by the continental glacier. In general, it can be said that fieldstone is a hard and strong stone suitable for use as a building material, which due to its density and low porosity can be used in underground and other supporting structures. These properties mean that fieldstone’s thermal conductivity is high, which is why it is not suitable for building dwellings. It has most commonly been used to build stables, cellars, barns and, to a lesser extent, taverns and other public buildings.Fieldstone is a material with a small ecological footprint which does not participate directly in the carbon cycle, as does timber. Fieldstone processing and transport is relatively energy-intensive, but this is compensated for by the longevity of the structures made. Visually, fieldstone is a very strong and eye-catching material. The surface of each stone is different, making each structure unique. The strong visual message and the long tradition of using fieldstone as a building material are the main factors that guarantee that there are people in Estonia who still commission fieldstone buildings and smaller items.
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Peebo, Alo, and Madis Rennu. "Maakivi ehitusmaterjalina: töötlemine ja kasutus." Studia Vernacula 4 (November 5, 2013): 73–86. http://dx.doi.org/10.12697/sv.2013.4.73-86.
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Fieldstone has been used as a building material for many centuries. In Estonia, two large groups of stone suitable for building can be distinguished in terms of architectural outcome and construction technique: calcareous stones (mostly carbonate flagstone and dolomite) and granite boulders, or field stones. The latter cover a broad spectrum of natural igneous and metamorphic rocks (rapakivi granite, diabases, gneiss etc.). In this article, we focus on natural stone belonging to the second group: in particular how it can be processed – split with wedges or a sledgehammer – and historical means of transporting stones. We also take a look at the ethical, aesthetic and cultural aspects of fieldstone use.Field stones were carried to Estonia by the continental glacier. In general, it can be said that fieldstone is a hard and strong stone suitable for use as a building material, which due to its density and low porosity can be used in underground and other supporting structures. These properties mean that fieldstone’s thermal conductivity is high, which is why it is not suitable for building dwellings. It has most commonly been used to build stables, cellars, barns and, to a lesser extent, taverns and other public buildings.Fieldstone is a material with a small ecological footprint which does not participate directly in the carbon cycle, as does timber. Fieldstone processing and transport is relatively energy-intensive, but this is compensated for by the longevity of the structures made. Visually, fieldstone is a very strong and eye-catching material. The surface of each stone is different, making each structure unique. The strong visual message and the long tradition of using fieldstone as a building material are the main factors that guarantee that there are people in Estonia who still commission fieldstone buildings and smaller items.
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Chin, Huai-Shan, and Long-Sun Chao. "The Effect of Thermal Annealing Processes on Structural and Photoluminescence of Zinc Oxide Thin Film." Journal of Nanomaterials 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/424953.
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This study used radio frequency sputtering at room temperature to prepare a zinc oxide (ZnO) thin film. After deposition, the thin film was placed in a high-temperature furnace to undergo thermal annealing at different temperatures (300, 400, 500, and 600°C) and for different dwelling times (15, 30, 45, and 60 min). The objective was to explore the effects that the described process had on the thin film’s internal structure and luminescence properties. A scanning electron microscope topographic image showed that the size of the ZnO crystals grew with increases in either the thermal annealing temperature or the dwelling time. However, significant differences in the levels of influence caused by increasing the thermal annealing temperature or dwelling time existed; the thermal annealing temperature had a greater effect on crystal growth when compared to the dwelling time. Furthermore, the crystallization directions of ZnO (002), (101), (102), and (103) can be clearly observed through an X-ray diffraction analysis, and crystallization strength increased with an increase in the thermal annealing temperature. The photoluminescence measurement spectra showed that ultraviolet (UV) emission intensity increased with increases in thermal annealing temperature and dwelling time. However, when the thermal annealing temperature reached 600°C or when the dwelling time reached 60 min, even exhibited a weak green light emission peak.
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Chen, Yu Hui, Shun Cong Zhong, and Xiao Xiang Yang. "Nonlinear Thermo-Mechanical Coupled Modeling for the Analysis of Stress Distribution in Air-Plasma-Sprayed Thermal Barrier Coatings." Key Engineering Materials 577-578 (September 2013): 41–44. http://dx.doi.org/10.4028/www.scientific.net/kem.577-578.41.
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Thermo-mechanical coupled modeling of air-plasma-sprayed (APS) thermal barrier coatings (TBCs) on Ni-based alloy was investigated. In the computational models, the stress distribution in the depth direction of the TBCs and also the influence of mechanical properties in heating, dwelling and cooling thermal cycles, were investigated. Nonlinear relationship (e.g., convective heat transfer between surrounding environment and coatings, and thermal transfer between the different layers etc.) was considered in the modeling. The results showed that the stress significantly reduced in the dwelling stage because of stress relaxation. The maximum stress occurred in the peak at the BC/TGO interface and it was amplified at the cooling stage. Moreover, the internal stress in the BC and TGO layer had a slight increase when TGOs thickness increased whilst the stress in the TBC and Sub were essentially unchanged. In the present work, the cracks in BC coating and the BC/TGO interface cracks were simulated as well. The failure mechanism I/II of TBCs had been investigated and the results showed that there was no stress concentration in the vicinity of cracks near the peak at the top coating layer, however, due to crack propagation, factures happened near the peak at the BC/TGO interface.
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Fashuyi, Olugbenga S., and Mohammed T. Alfa. "User’s Lifestyle and the Thermal Performance of the Compound House: An Appraisal." Buildings 9, no. 7 (June 28, 2019): 155. http://dx.doi.org/10.3390/buildings9070155.
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This study examines the impact of thermal performance of Yoruba compound house on the user’s lifestyle to cope with discomfort hours. A compound house was simulated using Autodesk Ecotect software. The study found that the front and right sides of the building have the lowest temperatures due to the combined effects of indirect and interzonal heat transfers. The research highlighted that while the user’s lifestyle in the Yoruba compound house relies on the veranda to cope with discomfort hours, residents of multi-dwelling compound houses rely on a lifestyle of housing adjustments. The study concludes that the thermal properties of the Yoruba compound house are complemented by the user’s lifestyle to cope with the discomfort hours.
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Alzaharnah, Iyad T. "Thermal Stresses in Thick Walled Cylinders due to a Periodic Moving Heat Source: Effect of Material Properties." Advanced Materials Research 445 (January 2012): 627–30. http://dx.doi.org/10.4028/www.scientific.net/amr.445.627.
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nternal heating of hollow cylinders with moving periodic heat source is examined in relation to surface treatment applications. This study includes three different cylinder materials, namely aluminum, nickel and titanium. Effective stresses in the cylinder wall are found to be mainly attributed to longitudinal temperature gradients. The aluminum cylinder shows sharper longitudinal temperature gradients as compared to the nickel and the titanium cylinders, which is due to the high value of the aluminum specific heat capacity. However, the larger Eα (elasticity modulus × thermal expansion coefficient) values for nickel cylinder result in higher levels of stress although nickel and titanium cylinders exhibit similar longitudinal temperature profiles. During dwelling time for the heating source at a certain spot, titanium cylinder exhibits lower levels of temperature increase as compared to aluminum and nickel cylinders, due to its lower value of thermal conductivity.
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Bienvenido-Huertas, David, Miguel Oliveira, Carlos Rubio-Bellido, and David Marín. "A Comparative Analysis of the International Regulation of Thermal Properties in Building Envelope." Sustainability 11, no. 20 (October 10, 2019): 5574. http://dx.doi.org/10.3390/su11205574.
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To achieve the goals of reducing building energy consumption, regulations are being designed to guarantee the appropriate energy performance of buildings. Both European and South American countries establish requirements of thermal properties of building envelope according to the climate zone, thus implying notable differences in climate classifications and technical requirements. This research provides a general view of advantages and limitations between the different state regulations of three South American countries (Argentina, Brazil, and Chile) and three European countries (Spain, Portugal, and France). A total of 792 simulations were conducted with Energy Plus by considering 12 different dwelling typologies in 66 climate zones. Building envelopes were adapted to the regulations of the various countries. Results showed tendencies of performance clearly different between the South American and the European countries, with the latter being those with the lowest energy demands. The cluster analysis of distributions of energy demand revealed that buildings located in similar climates but in different countries present very different energy performances. This research opens up the discussion on the development of more demanding policies related to thermal properties of buildings. Also, the analysis at a continental scale could reduce the differences between countries and guarantee a more sustainable life for the building stock.
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Zatsepina, O. G., K. A. Ulmasov, S. F. Beresten, V. B. Molodtsov, S. A. Rybtsov, and M. B. Evgen'ev. "Thermotolerant desert lizards characteristically differ in terms of heat-shock system regulation." Journal of Experimental Biology 203, no. 6 (March 15, 2000): 1017–25. http://dx.doi.org/10.1242/jeb.203.6.1017.
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We compare the properties and activation of heat-shock transcription factor (HSF1) and the synthesis of a major family of heat-shock proteins (HSP70) in lizard species inhabiting ecological niches with strikingly different thermal parameters. Under normal non-heat-shock conditions, all desert-dwelling lizard species studied so far differ from a northern, non-desert species (Lacerta vivipara) in the electrophoretic mobility and content of proteins constitutively bound to the regulatory heat-shock elements in the heat-shock gene promoter. Under these conditions, levels of activated HSF1 and of both HSP70 mRNA and protein are higher in the desert species than in the non-desert species. Upon heat shock, HSF1 aggregates in all species studied, although in desert species HSF1 subsequently disaggregates more rapidly. Cells of the northern species have a lower thermal threshold for HSP expression than those of the desert species, which correlates with the relatively low constitutive level of HSPs and high basal content of HSF1 in their cells.
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Wang, Cao, Zhe Zhao, and Lai Fei Cheng. "Finite Element Modeling of Temperature Distribution in Spark Plasma Sintering." Key Engineering Materials 434-435 (March 2010): 808–13. http://dx.doi.org/10.4028/www.scientific.net/kem.434-435.808.
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A finite element model (FEM) is developed to simulate the temperature distribution in the sample/die/punch assembly during the spark plasma sintering (SPS) process. A thermal–electrical coupled model with temperature dependent thermal and electrical properties is implemented. The simulation studies were conducted using COMSOL and a range of heating-rates and die sizes were considered. Also, both temporary and equilibrium condition during heating process were evaluated in order to express the real temperature development in the sintering. During the spark plasma sintering process, the temperature difference between the sample center and the die surface depend on the heating-rate and die size. The simulation results also revealed that the temperature gradient during the heating process is much bigger than that in the dwelling period. It is necessary to consider the temporary state during the spark plasma sintering process in order to guarantee a well–controlled microstructure, especially in non-conductive ceramic materials.
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Vasco, Diego A., Manuel Muñoz-Mejías, Rodrigo Pino-Sepúlveda, Roberto Ortega-Aguilera, and Claudio García-Herrera. "Thermal simulation of a social dwelling in Chile: Effect of the thermal zone and the temperature-dependant thermophysical properties of light envelope materials." Applied Thermal Engineering 112 (February 2017): 771–83. http://dx.doi.org/10.1016/j.applthermaleng.2016.10.130.
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Kazemi, Mansure, Bahareh Nazari, Jafar Ai, Nasrin Lotfibakhshaiesh, Ali Samadikuchaksaraei, Seyed Mohammad Tavangar, and Mahmoud Azami. "Preparation and characterization of highly porous ceramic-based nanocomposite scaffolds with improved mechanical properties using the liquid phase-assisted sintering method." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 233, no. 9 (August 22, 2018): 1854–65. http://dx.doi.org/10.1177/1464420718795186.
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Recent advances in the field of biomaterials have led to the development of ceramic–matrix nanocomposites with enhanced mechanical properties, which is essential for hard tissue scaffolds. In this study, the improvement in mechanical and biological properties of β-tricalcium phosphate reinforced with 45S5 bioactive glass under different sintering conditions was studied. In order to improve the thermal stability and biological responses, β-tricalcium phosphate was doped with 5 mol% strontium ions. Highly porous nanocomposites, with different weight ratios of Sr-tricalcium phosphate/bioactive glass (75/25, 50/50, 25/75), were fabricated through the foam replication method by sintering samples under various thermal conditions (1200–1250 ℃/0–1 h). The effects of bioactive glass content and sintering parameters on microstructure and mechanical behaviors of the nanocomposites were assessed. The obtained results showed that increasing 45S5 bioactive glass content, sintering temperature, and dwelling time gradually improved the mechanical properties of final products which were ascribed to the improved ceramic densification. The composites with the optimal compressive strength were selected to apply in further characterization and cell culture experiments. The selected scaffolds showed excellent bioactivity since a continuous layer of minerals covered the entire surface of composites after immersion in simulated body fluid solution for two weeks. Moreover, the cell culture studies demonstrated that the composite scaffolds could well support the attachment and proliferation of MG-63 osteoblast-like cells. This investigation clearly concluded that the appropriate incorporation of 45S5 bioactive glass into the β-tricalcium phosphate matrix can effectively promote the mechanical behavior, bioactivity, and biocompatibility of the resultant composite scaffolds.
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SANIP, S. M., Z. R. Z. ABIDIN, N. BUANG, M. AZIZ, and A. F. ISMAIL. "EFFECTS OF HEAT TREATMENT ON SYNTHETIC GRAPHITES FOR CARBON NANOTUBES SYNTHESIS." International Journal of Nanoscience 03, no. 04n05 (August 2004): 671–75. http://dx.doi.org/10.1142/s0219581x04002516.
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Carbon materials are well known for their excellent adsorbent property towards gases. Much work has been done to improve the properties of carbon materials as to enhance their absorption capacity towards gases. Recent developments have resulted in the discovery of novel carbon materials such as carbon nanotubes. Numerous researches have shown that carbon nanotubes have excellent capacity for hydrogen storage. However, significant research has been undertaken to further improve the adsorption capacity through the advancement in synthesis methods for the fabrication of carbon nanotubes. Among the starting material widely employed for synthesis of carbon nanotubes is high purity graphite. Therefore, purpose of this work is to investigate the effect of thermal treatment on several synthetic graphites. Thermal treatment was conducted at temperatures ranging from 400–800°C at different dwelling times. The morphology and surface analysis of the graphites were examined using Scanning Electron Microscope and nitrogen gas adsorption techniques, respectively. It was found that temperature, time and conditions of treatment significantly change the surface structure of the graphites. A decrease in particle size was observed due to the release of internal surface area.
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Basir, Al, Abu Bakar Sulong, Nashrah Hani Jamadon, and Norhamidi Muhamad. "Physical Properties of Sintered Stainless Steel 17-4PH Micro-Part Processed by MicroPowder Injection Molding." Jurnal Kejuruteraan 34, no. 6 (November 30, 2022): 1209–14. http://dx.doi.org/10.17576/jkukm-2022-34(6)-21.
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Micro-powder injection molding (μPIM) is a modification of powder injection molding (PIM) process and a globally recognized manufacturing process route that can be used largely to produce sophisticated micro-sized components using a wide range of metals and ceramics. The demand of μPIM process is currently increasing in various applications in telecommunication, electronics, aerospace, biomedical, and automotive industries. In this research work, sintering at three different temperatures between 1250 °C and 1350 °C at a heating rate of 10 °C/min with a dwelling period of 3 h on micro-injection molded and debound (solvent and thermal) micro-sized components of stainless steel 17-4PH (SS 17-4PH) was carried out. After the sintering operation, defect-free SS 17-4PH micro-specimens were achieved. The relative density, which is referred to as an important physical property of SS 17-4PH micro-parts, increased substantially from 95.3% to 97.5% when the sintering temperature was enhanced from 1250 °C to 1350 °C. The maximum shrinkage of 12.9% was observed in micro-sized specimens at the sintering temperature of 1350 °C. After the completion of sintering process, the findings revealed that SS 17-4PH micro-parts can be produced successfully on the grounds of μPIM process employing the SS 17-4PH feedstock with powder loading of 69 vol.%.
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Hammas, Aghiles, Gisèle Lecomte-Nana, Imane Daou, Nicolas Tessier-Doyen, Claire Peyratout, and Fatima Zibouche. "Kaolinite-Magnesite or Kaolinite–Talc-Based Ceramics. Part II: Microstructure and the Final Properties Related Sintered Tapes." Minerals 10, no. 12 (December 1, 2020): 1080. http://dx.doi.org/10.3390/min10121080.
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In recent decades, talc and kaolinite have been widely used as raw materials for the ceramic industry. In this study, the final characteristics of kaolinitic clay mixed with 6 mass% of magnesite obtained in our previous work were compared with those obtained with mixtures of kaolin (kaolin BIP) and talc (as the source of magnesium oxide). However, different amounts of talc in the kaolin powder were studied, namely 10, 30, and 50 mass% of added talc (with respect to kaolin + talc). The tape casting process was used during this work in order to manufacture the green tapes in an aqueous system with 0.2 mass% of dispersant. Subsequently, the green tapes were heated to 1000 and 1100 °C with a dwelling time of 12 min. The green and sintering tapes were characterized using the following techniques: DTA/TG, X-ray diffraction, porosity, and flexural strength analyses. The results obtained from our previous work indicate that the specimen with 6 mass% of MgCO3 sintered at 1200 °C for 3 h exhibited the best performances, with high flexural strength and weak porosity value—117 MPa and 27%—respectively. As results from this study, the optimal mechanical and thermal properties of sintering tapes were obtained for the specimen with 10 mass% of added talc sintered at 1100 °C. Indeed, this specimen exhibited 50 MPa and 43% of stress to rupture and apparent porosity, respectively.
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Soto, Flavio Roberto Ceja, José de Jesús Pérez Bueno, Maria Luisa Mendoza López, Martín Hernández Chavela, Martha Elva Pérez Ramos, and Alejandro Manzano-Ramírez. "Hydrothermal Evaluation of Vernacular Housing: Comparing Case Studies of Waste PET Bottles, Stone, and Adobe Houses." Buildings 12, no. 8 (August 3, 2022): 1162. http://dx.doi.org/10.3390/buildings12081162.
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This work shows the humidity and thermal evaluation of different case studies of houses. The analyses focused on room prototypes and houses built in different regions of Querétaro, México. Three different climatic zones were included with the evaluations of houses and prototypes. The assessments of internal and external parameters in residential buildings are also shown. The internal parameter measurements were done with hydro-thermometers and thermography images. Six structures were evaluated, one of the conventional housing materials and five of alternative or vernacular materials. The predicted mean vote (PMV) and the predicted percentage dissatisfied (PPD) were determined using the average temperature and relative humidity values, and they were considered to be dynamic because they can change depending on many factors. The six dwelling insulating properties were associated with their construction materials, design, location, and other factors. The six houses have many differences, but considering their behavior in their location, the two floor porous stone house got the best results. On the contrary, the flagstone house with a gabled roof of galvanized sheets had a cold perception despite many advantageous elements, failing to provide comfort in such a cold location. Contrasting these with other adobe constructions, the analyzed one had low thermal insulation, which was explained by its characteristics. PET and adobe uninhabited prototypes had medium to cold perceptions. The PET prototype has excellent and adjustable insulations, both on temperature and RH, considering the passive illumination and ventilation of its glass bottle skylights.
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Salloomi, Kareem N., Furat I. Hussein, and Sanaa N. M. Al-Sumaidae. "Temperature and Stress Evaluation during Three Different Phases of Friction Stir Welding of AA 7075-T651 Alloy." Modelling and Simulation in Engineering 2020 (February 18, 2020): 1–11. http://dx.doi.org/10.1155/2020/3197813.
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The current study performs an explicit nonlinear finite element simulation to predict temperature distribution and consequent stresses during the friction stir welding (FSW) of AA 7075-T651 alloy. The ABAQUS® finite element software was used to model and analyze the process steps that involve plunging, dwelling, and traverse stages. Techniques such as Arbitrary Lagrangian–Eulerian (ALE) formulation, adaptive meshing, and computational feature of mass scaling were utilized to simulate sequence events during the friction stir welding process. The contact between the welding tool and workpiece was modelled through applying Coulomb’s friction model with a nonlinear friction coefficient value. Also, the model considered the effect of nonlinear material properties as well as heat transfer conditions such as heat losses due to convection and thermal contact conductance between the workpiece and the backing plate interface on the thermal history. To validate the computational model results, an experimental procedure was carried out to measure temperature history on both sides of the specimen as well as the plunging force throughout the whole process time. The results obtained showed that symmetrical temperature distribution throughout the workpiece width was distinguished, implying that the tool rotation has a minor effect on the final temperature distribution. In addition, asymptotic V shape with high gradient temperature value in the weld nugget region after the full plunging was distinguished. Mechanical stresses and related plastic deformations generated, while achieving the FSW samples were evaluated in addition to the tool reaction force and heat generated to protect against tool failure.
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Tsakiris, Violeta, Wilhelm Kappel, Georgeta Velciu, Cristian Seitan, Dorinel Talpeanu, Florentina Clicinschi, Carmen Hajdu, and Virgil Marinescu. "Joining of Y2O3-Doped Aluminum Nitride with High Density Graphite by Spark Plasma Sintering." Advanced Materials Research 1111 (July 2015): 260–65. http://dx.doi.org/10.4028/www.scientific.net/amr.1111.260.
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High density graphite disks and aluminum nitride ceramics powders have been utilized to obtain joints by Spark Plasma Sintering technique. The joining was carried out in vacuum, at temperatures of 1700°C, 1800°C and 1900°C, under the pressure of 50 MPa with a constant dwelling time of 5 minutes The AlN ceramics to be joined were also synthesized by ceramic technology standard route by using AlN powders and 2.5 % wt.Y2O3 powders as sintering additive, which were added in order to increase densification rate and by thus, thermal conductivity. The joining of AlN/C was performed both without and with the aid of a ceramic powder composite AlN+Y2O3+C film, as interlayer. Besides the crystalline phases (AlN and C), the Al5Y3O12 compounds with a cubic crystallographic structure were identified by X-ray diffraction. The optical microscopy images revealed that all samples, both without and with film as interlayer, had strong joined areas, without any defects and discontinuities at interfaces. The Vickers microhardness and Young Modulus values measured by nanoindentation have shown that using of the film as intermediary layer was leading to the highest values of mechanical properties (HV = 8 – 23 GPa and E= 227-512 GPa) at the AlN/C joints interfaces.
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Almeida, R. M. S. F., P. Paula, A. Santos, N. M. M. Ramos, J. M. P. Q. Delgado, and V. P. de Freitas. "Hygrothermal Performance and Degradation of Gypsum Houses in Different Brazilian Climates." Diffusion Foundations 3 (February 2015): 137–49. http://dx.doi.org/10.4028/www.scientific.net/df.3.137.
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This work consisted of two main lines of research: one of a literature review and other of simulation. In the first part, a modular constructive system based on gypsum blocks is presented. This constructive system reduces the manpower considerably, the time of execution and the final costs of construction. However, the durability assessment should be analysed but first its implementation and performance along the country must analysed.In this work a preliminary experimental characterization of the thermal conductivity, vapour permeability and water absorption coefficient of two different samples of gypsum plasters from the northeast Brazil (plaster pole of Araripe, Pernambuco) was performed. The experimental and analytical procedures followed either international standards or well-established methodologies, supporting the analysis of gypsum walls hygrothermal behaviour. The measured properties were adopted as inputs to hygrothermal simulation software and the analysis of gypsum based exterior walls was conducted for different climate zones and exposure conditions. The study demonstrates the durability issues that may arise in each location, due to differences in hygrothermal action.The other simulation part included hygrothermal advanced modelling, using the EnergyPlus software. The numerical results carried out allow a discussion over the interior comfort and durability of this modular constructive system. In this paper, the computer simulation model and the results of a parametric analysis of the dwelling performance on the eight climatic regions defined in Brazilian regulations are presented. The model was validated using the in situ measurements of air temperature.
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Bezerra de Sousa, Sabrina, and Paulo Henriques da Fonseca. "Analysis of the socio-environmental impact of abandoned property." REVISTA INTERDISCIPLINAR E DO MEIO AMBIENTE (RIMA) 4, no. 1 (March 4, 2022): e135. http://dx.doi.org/10.52664/rima.v4.n1.2022.e135.
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The study about absentee ownership, specifically about its impacts caused, as well the probable causes about this phenomenon represent a direct relation with human rights, especially those who protect the phenomenon of social inequality which will be the object of this scientific article. Thus, aimed to analyze a possible origin of the absentee ownership in context of human development with the nomadic lifestyle, characterized by the absence of fixed dwelling and a constant process of migration to another regions. Thereat and using the contemporary context as parameter, it was studied on legal texts aiming establish the nomenclatures adopted, as well to understand their insertion in the social environment, specifically in São Paulo and Rio de Janeiro using as a focus the right to housing as fundamental and inherent in the condition of the human person. Therefore, used as a methodology the bibliographical, documental and legislative reviews about the topic, concomitant with the empirical method that served to analyze the situation of the properties. In this way, observed along with the data released by the 2010 Census, over 200 thousand in the number of abandoned properties in relation to the Brazilian housing deficit. Therefore, some initial theses served as a parameter to guide the study on the owner's inertia, ranging from waiting for the property to appreciate to the migration of a portion of the population to neighboring regions, as they cannot afford the high cost of the central region of the city, which can justify the object-problem of the work.
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Rangiwhetu, Lara, Nevil Pierse, Helen Viggers, and Philippa Howden-Chapman. "Cold New Zealand Council Housing Getting an Upgrade." Policy Quarterly 14, no. 2 (May 14, 2018). http://dx.doi.org/10.26686/pq.v14i2.5096.
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As people spend most of their time at home, residential thermal conditions are important. Central government debate about minimum temperature requirements for rental properties requires an evidence base of indoor temperature data. We collected temperature, humidity and energy data from 49 council housing dwellings in Wellington over winter, and self-reported thermal comfort and heating behaviour. Mean indoor temperature was 14.9°C, colder than the national average, with 67% of readings under 16°C, which the World Health Organization associates with health implications. With New Zealand’s high rate of excess winter mortality and children hospitalised for housing-related diseases, cold housing should be addressed.
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Sinha, Arijit, Rakesh Gupta, and John A. Nairn. "Thermal degradation of bending properties of structural wood and wood-based composites." Holzforschung 65, no. 2 (March 1, 2011). http://dx.doi.org/10.1515/hf.2011.001.
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Abstract Wood and wood-based composites are being used extensi-vely in single-family residential dwellings. Therefore, it is important to categorize their response when exposed to elevated temperatures for a sustained period of time. In fire-resistant design for wood structures, the main goal is to ensure that enough structural integrity is maintained, during and after a fire, to prevent collapse and to maintain means of egress. Another goal is an ability to assess post-fire structural integrity and residual strength of an existing structure. The objectives of this study are: (a) to study the effect of temperature and exposure time on bending strength (MOR) and stiffness (MOE) of solid sawn lumber (SSL), laminated veneer lumber (LVL), oriented strand board (OSB) and plywood; and (b) to develop predictive relations between different temperatures and times of exposure and the thermal degradation of strength. A total of 1080 samples were tested in static bending under various heat treatments. The results indicated that exposure to elevated temperature caused significant degradation of bending strength and stiffness. A statistical regression-based model and a kinetics-based model were developed and evaluated for predicting the strength loss of wood and wood-based composites as a function of thermal exposure temperature and exposure time. The kinetics-based model fit the data better and predictions consistently matched the observed values, making the model preferred over the regression approach.
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Curiel-Sanchez, Francisco Gibranny, and Ixchel Astrid Camacho-Ixta. "Propuesta de materiales termoaislantes para desarrollo de casa-habitación adecuada a cambios climáticos con eficiencia energética." Revista de Arquitectura y Diseño, September 30, 2019, 1–5. http://dx.doi.org/10.35429/jad.2019.9.3.1.5.
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The condition of climate change is attributed directly or indirectly to activities related to the human being, as a more transcendental effect the increase of temperature is highlighted. Such a condition is not taken into account in the development of current constructions, so it is sought to propose the use of thermal insulating materials that will give a thermal comfort to the user and a reduction of energy use, which in turn will be an environmental advantage. There are various types of thermal insulating materials, however, it is proposed to be sustainable, as it is intended not to contribute to climate change and to meet the appropriate specifications of the building envelope, in order to ensure the users comfort of current and future dwellings, different factors, such as orientation, as well as specific parameters, will be taken into account as part of the development of the aforementioned ones. The construction development of the current house-room does not take into account the continuous thermal alterations that occur by the continuous climate change, ignoring the basic needs of the thermal comfort of the user; so sustainable materials are recommended, which meet thermoinsulating properties without causing an environmental impact.
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FLORES CONDORI, ARTURO. "CONSTRUCCIÓN DE UNA VIVIENDA SOLAR EN BASE A LAS PROPIEDADES TERMOFISICAS Y EVALUACIÓN EXPERIMENTAL DE SU CONFORT TÉRMICO EN ILAVE." Revista Investigaciones Altoandinas - Journal of High Andean Investigation 16, no. 01 (June 30, 2014). http://dx.doi.org/10.18271/ria.2014.101.
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<h4 class="text-primary">Resumen</h4><p style="text-align: justify;">El presente artículo consistió en la construcción de una vivienda solar pasivo a base de propiedades termofísicas (Conductividad térmica, calor específico, difusividad térmica y inercia térmica) y desarrollar una evaluación experimental del rendimiento térmico aportado por los elementos constructivos, en una comunidad rural Colloco - Ilave, provisto de adecuado aislamiento térmico en la envolvente (doble pared de adobe, en el cielo raso: pajacarrizo-yeso y en el piso: tierra apisonada-cama de piedra-plástico-paja y totora), ubicación, la orientación y un sistema de acumulación de energía adecuadamente diseñada a base a encapsulado de piedras andesitas porosas y de totora. La distribución de energía calorífica almacenada fue primordial al ambiente dormitorio que esto permite el aprovechamiento de la energía solar para lograr que la temperatura al interior de la vivienda sea más confortable. Se realizó el análisis del comportamiento térmico de la vivienda construida y la vivienda rural típica, para lo cual se tomaron los datos meteorológicos de la zona (temperatura, humedad relativa, velocidad del viento y radiación solar), también se registraron la temperatura y humedad relativa del aire en el ambiente interior y exterior de las viviendas desde 19 de junio al 02 de julio del 2013. Obteniéndose en la vivienda construida las temperaturas máximas y mínimas de 15.85ºC y 11.88ºC respectivamente. Según la evaluación de la vivienda construida se aprecia un incremento de temperatura mínimo de 6.26°C, respecto a la vivienda típica. Para validar estos resultados experimentales, se ha utilizado el programa de simulación térmica EnergyPlus para los datos meteorológicos de la zona (3 868 msnm), comprobándose por el método correlativo, el factor de correlación fue r=0.92575. Este incremento de la temperatura en el interior de la vivienda construida contribuye alcanzar un confort térmico, permitiendo una condición de vida saludable para el poblador rural.</p><p><strong>PALABRAS CLAVE: </strong>* confort térmico * energía solar * propiedades termofísica * simulación térmica</p><h4 class="text-primary">ABSTRACT</h4><p><strong>CONSTRUCTION OF A SOLAR DWELLING BASED ON THERMOPHYSICAL PROPERTIES AND EXPERIMENTAL EVALUATION OF THERMAL COMFORT - ILAVE, PUNO - PERU»</strong></p><p style="text-align: justify;">The present article consists in the construction of a passive solar house based on the study of thermophysical properties (thermal conductivity, specific heat, thermal diffusivity and thermal inertia). We developed an experimental evaluation of the thermal efficiency contributed by different constructive materials, In the rural community of Colloco - Ilave. Once adequate thermal insulation was provided in the enveloping surface (double wall construction of sun-dried adobe brick, a false ceiling with: straw, bamboo and plaster. In the floor: tamped soil, stone bed, plastic, straw and totora reed). Location and position of the solar home in coordination with an energy accumulation system adequately designed with an encapsulation of porous Andesitic stones and Totora reed. Distribution of the stored thermal energy was directed primarily to the main bedroom, this enabled adequate use of solar energy in order to achieve a comfortable temperature within the dwelling. We analyzed the thermal behavior of both this experimental structure and that of a common rural dwelling; taking the interior and exterior meteorological readings found in the two dwelling types. (temperature, relative humidity, wind velocity and solar radiation). Between June 19th and July 2nd, the temperature and relative humidity of the interior of the experimental structure measured a max. of 15.85ºC (60.53ºF) and 11.88ºC (53.384ºF) respectively. According to a general evaluation of the experimental structure, there was a temperature increment of 6.26°C (=¿?ºF) compared to the average temperature of a normal dwelling. In order to confirm these experimental results we used the thermic simulation software EnergyPlus, entering the meteorological data of the area (3,868 meters above sea level=12690.3 ft.) using the correlative method and a correlative factor of r=0.92575. This higher temperature inside of the experimental structure contributes to attaining a thermic comfort allowing for a healthy living condition for the rural inhabitant.</p><p><strong>KEY WORDS: </strong>* thermal comfort * solar energy * thermophysical properties * thermal simulation</p>
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Erzurumluoglu, Levent, Md Mahbubor Rahman, Tuba Demirel, and Ismail Karacan. "Fabrication of carbon fibers from the cupric ion impregnated and thermally stabilized poly(hexamethylene adipamide) precursor." Journal of Industrial Textiles, December 14, 2021, 152808372110569. http://dx.doi.org/10.1177/15280837211056984.
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The conversion of poly (hexamethylene adipamide) or polyamide 66 precursor fiber to carbon fibers was accomplished through thermal stabilization and carbonization processes. Thermal stabilization was conducted of cupric chloride (CuCl2)–ethanol-impregnated polyamide 66 (PA66) fibers in the air. To determine the influence of heating rate on the fiber structure and properties of the resultant carbon fibers, carbonization experiments were performed at selected temperatures of 500, 700, 900, and 1100°C using 2.5 and 5 °C/min heating rates with no dwelling. The results conclusively revealed that the volume density and tensile properties of the PA66 fiber were higher at 2.5 °C/min heating rate. After fixing the heating rate as 2.5°C/min, further carbonization experiments were conducted at temperatures from 500 to 1100°C, using increments of 100°C with no dwelling time. Linear density, volume density, fiber diameter, carbon yield, elemental composition, tensile, and electrical properties exhibited a strong dependence on the carbonization temperature. After taking into account the effects of structural defects (i.e., microvoids), tensile strength, and tensile modulus of the carbon fibers increased to 794 MPa and 92.4 GPa, respectively, when carbonized at 1100°C. X-ray diffraction analysis of the carbon fibers further revealed the existence of a greatly disordered (i.e., amorphous) structure, which developed during the carbonization process. FT-IR analysis confirmed the formation of highly aromatic carbon clusters at temperatures of 500°C and higher. The outcomes of electrical conductivity in this study confirm that the PA66 precursor was converted into a semi-conducting state once it was carbonized.
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Maziarz, Marta, Richard K. Broughton, Luca Pietro Casacci, Anna Dubiec, István Maák, and Magdalena Witek. "Thermal ecosystem engineering by songbirds promotes a symbiotic relationship with ants." Scientific Reports 10, no. 1 (November 23, 2020). http://dx.doi.org/10.1038/s41598-020-77360-z.
Full textAbstract:
AbstractNesting birds can act as thermal ecosystem engineers by providing warm habitats that may attract arthropods to colonise the nest structure. This cohabitation of birds and nest-dwelling invertebrates may foster symbiotic relationships between them, but evidence is lacking. We investigated whether ants are attracted to bird nests by the heat generated by the hosts, and/or the nests’ structural insulation properties, to raise their broods (larvae and/or pupae) in advantageous thermal conditions. We found that the endothermic activity of birds within their nests created ‘heat islands’, with thermal conditions potentially promoting the survival and development of ant larvae in cool environments. We experimentally confirmed that the presence of heat within bird nests, and not the structure itself, attracted the ants to colonise the nests. As ants might benefit from exploiting warm bird nests, this may be a previously overlooked commensal, mutualistic or parasitic relationship which may be ecologically significant and globally widespread among various nesting birds and reproducing ants. Similar interspecific interactions may exist with other arthropods that reproduce in avian and mammalian nests. Further research is needed to reveal the nature of these relationships between such taxa, and to understand the role of warm-blooded animals as thermal ecosystem engineers.
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Domingos, Renata, Emeli Guarda, Elaise Gabriel, and João Sanches. "Influence of trees on the energy consumption of a social housing in mid-western Brazil." WEENTECH Proceedings in Energy, September 8, 2019, 53–65. http://dx.doi.org/10.32438/wpe.4819.
Full textAbstract:
In the last decades, many studies have shown ample evidence that the existence of trees and vegetation around buildings can contribute to reduce the demand for energy by cooling and heating. The use of green areas in the urban environment as an effective strategy in reducing the cooling load of buildings has attracted much attention, though there is a lack of quantitative actions to apply the general idea to a specific building or location. Due to the large-scale construction of high buildings, large amounts of solar radiation are reflected and stored in the canyons of the streets. This causes higher air temperature and surface temperature in city areas compared to the rural environment and, consequently, deteriorates the urban heat island effect. The constant high temperatures lead to more air conditioning demand time, which results in a significant increase in building energy consumption. In general, the shade of the trees reduces the building energy demand for air conditioning, reducing solar radiation on the walls and roofs. The increase of urban green spaces has been extensively accepted as effective in mitigating the effects of heat island and reducing energy use in buildings. However, by influencing temperatures, especially extreme, it is likely that trees also affect human health, an important economic variable of interest. Since human behavior has a major influence on maintaining environmental quality, today's urban problems such as air and water pollution, floods, excessive noise, cause serious damage to the physical and mental health of the population. By minimizing these problems, vegetation (especially trees) is generally known to provide a range of ecosystem services such as rainwater reduction, air pollution mitigation, noise reduction, etc. This study focuses on the functions of temperature regulation, improvement of external thermal comfort and cooling energy reduction, so it aims to evaluate the influence of trees on the energy consumption of a house in the mid-western Brazil, located at latitude 15 ° S, in the center of South America. The methodology adopted was computer simulation, analyzing two scenarios that deal with issues such as the influence of vegetation and tree shade on the energy consumption of a building. In this way, the methodological procedures were divided into three stages: climatic contextualization of the study region; definition of a basic dwelling, of the thermophysical properties; computational simulation for quantification of energy consumption for the four facade orientations. The results show that the façades orientated to north, east and south, without the insertion of arboreal shading, obtained higher values of annual energy consumption. With the adoption of shading, the facades obtained a consumption reduction of around 7,4%. It is concluded that shading vegetation can bring significant climatic contribution to the interior of built environments and, consequently, reduction in energy consumption, promoting improvements in the thermal comfort conditions of users.