Kinds Of Roofs Research Articles

Wind Load Analysis on Gable Roof of Low-Rise Building

The effect of pressure because of the winds on the exterior of gable roof of a low-rise single-storey building has been analyzed in present research using CFD simulation. Roof slope, which is most important factor for safety of structure was taken into consideration. Many past researchers have studied roofed structures but the majority of these researches have been carried on flat roofs, hip roof, spherical roofs, pyramidal roofs. There is need of researches that analyses effect of winds on gable roofs as these kinds of roofs are generally more susceptible to wind damage. ANSYS ICM is used for modeling and meshing and ANSYS Fluent for simulation. Results are extracted here using CFD post. In this very study three models with slope ang 10°, 20° and 30° with same incidence angle 0° were examined. This study analyses the effect of slope of the roof and angle of incidence of wind. The streamlines of velocity around the building model and pressure coefficient (Cp ) contours on the surfaces of the roof are opted here to represent the results. When results were plotted it was found that pressure coefficients were switching from negative to positive as the slope of the roof increases and the formation of vortex on leeward gets complicated as we go on increasing the slopes.

‘Homeless in their own home’: the case of home-deprived single mothers

Abstract Institutional statistics and academic research in Israel tend to present a partial description of the gender characteristics of the problem of Israeli homelessness. They often focus on the manifest aspect of the phenomenon, which essentially characterizes homelessness as men living on the streets. By doing so, they ignore its hidden aspect, especially its feminine characteristics. Based on 10 interviews that I conducted with Jewish and Arab women, who are home-deprived single mothers, the article reveals how these women, who have some kind of roof over their heads, have living arrangements that are characterized by a lack of stability and security. The women engage in a number of strategies, which include, for example: living with family and friends, constantly moving from one apartment to another, refusing to evacuate, and squatting in empty apartments, which make them invisible homeless, hidden from the public eye. The analysis of the women's coping strategies reveals that the women are not passive objects of the hegemonic discourse, but rather active members of society. The women engage in resistance and redefine the boundaries of the social problem of homelessness, in order to meet their parental obligations and ensure that their children will have a roof over their heads. Keywords: hidden homelessness; women; feminism; social problem, resistance, Israel

The Impact of Green Roofs on the Parameters of the Environment in Urban Areas—Review

This study presents the results of a review of publications conducted by researchers in a variety of climates on the implementation of ‘green roofs’ and their impact on the urban environment. Features of green roofs in urban areas have been characterized by a particular emphasis on: Filtration of air pollutants and oxygen production, reduction of rainwater volume discharged from roof surfaces, reduction of so-called ‘urban heat islands’, as well as improvements to roof surface insulation (including noise reduction properties). The review of the publications confirmed the necessity to conduct research to determine the coefficients of the impact of green roofs on the environment in the city centers of Central and Eastern Europe. The results presented by different authors (most often based on a single case study) differ significantly from each other, which does not allow us to choose universal coefficients for all the parameters of the green roof’s impact on the environment. The work also includes analysis of structural recommendations for the future model green roof study, which will enable pilot research into the influence of green roofs on the environment in urban agglomerations and proposes different kinds of plants for different kinds of roofs, respectively.

Integrating conventional and green roofs for mitigating thermal discomfort and water scarcity in urban areas

This paper aims to evaluate the possibility of using the roofs of habitations in Caruaru city in the semiarid region of Pernambuco, Brazil, for two purposes: as green roofs to mitigate extreme temperatures inside the houses and for rainwater harvesting and storage for potable purposes. For this, a preliminary study was carried out with inside and outside temperature monitoring of rooms with a green roof and conventional roof to verify the thermal variation in a real situation. Furthermore, the potential of rainwater harvesting for Caruaru city was evaluated based on precipitation data provided by the Water National Agency and an estimation of the available roof area (buildings and houses). In this context, two scenarios were analysed: (scenario 1) the whole roof surface was used for rainwater harvesting and saving and (scenario 2) green roofs were implanted in part of the roofs.The results of this preliminary study indicated that the use of green roofs resulted in lower temperature variations throughout the day, decreased internal temperatures, and decreased thermal amplitude in relation to a conventional roof (with tiles). Regarding the reduction of the catchment area because of the recommended use of green roofs in a semiarid region, considering green roof application just over the bedrooms (which was considered to cover 16 m2 in total), the water saving potential of the public supply system decreased, with a monthly average of 23.13% versus 28.43% (without green roofs). Implanting green roofs in part of the roofs of houses, although there is a reduction in the rainwater volume that can be harvested, can result in an increase in thermal comfort, whereas this is not feasible with the use of the entire roof area to harvest potable water. Thereby, the results indicate that the simultaneous use of the two kinds of roofs (conventional and green) is feasible even in a semiarid climate.

Thermal performance and energy savings of white and sedum-tray garden roof: A case study in a Chongqing office building

This study presents the experimental measurement of the energy consumption of three top-floor air-conditioned rooms in a typical office building in Chongqing, which is a mountainous city in the hot-summer and cold-winter zone of China, to examine the energy performance of white and sedum-tray garden roofs. The energy consumption of the three rooms was measured from September 2014 to September 2015 by monitoring the energy performance (temperature distributions of the roofs, evaporation, heat fluxes, and energy consumption) and indoor air temperature. The rooms had the same construction and appliances, except that one roof top was black, one was white, and one had a sedum-tray garden roof. This study references the International Performance Measurement and Verification Protocol (IPMVP) to calculate and compare the energy savings of the three kinds of roofs. The results indicate that the energy savings ratios of the rooms with the sedum-tray garden roof and with the white roof were 25.0% and 20.5%, respectively, as compared with the black-roofed room, in the summer; by contrast, the energy savings ratios were −9.9% and −2.7%, respectively, in the winter. Furthermore, Annual conditioning energy savings of white roof (3.9 kWh/m2) were 1.6 times the energy savings for the sedum-tray garden roof. It is evident that white roof is a preferable choice for office buildings in Chongqing. Additionally, The white roof had a reflectance of 0.58 after natural aging owing to the serious air pollution worsened its thermal performance, and the energy savings reduced by 0.033kWh/m2·d. Evaporation was also identified to have a significant effect on the energy savings of the sedum-tray garden roof.

Numerical analysis on thermal performance of roof contained PCM of a single residential building

The phase change material (PCM) applied in the roof can decrease the building energy consumption and improve the thermal comfort by enhancing the thermal energy storage capacity of building envelope. In the present work, the thermal performance of different kinds of roofs with and without PCM in Northeast and cold area of China, i.e. common roof and PCM roofs, have been investigated numerically. This study also explored the influencing factors of thermal behavior of the roofs, such as solar radiation intensity, transition temperature and latent heat of PCM, roof slope, PCM layer thickness, and absorption coefficients of external roof surface. The results show that the PCM roofs effect on the temperature delay in the room is very strong and the delay time of temperatures peak of base layer in PCM roofs are beyond 3h than common roof. The effect of transition temperature and latent heat of PCM on the thermal performance of roofs is relatively weak, compared with the roof slope, PCM layer thickness and absorption coefficients of external roof surface.

A novel solar multifunctional PV/T/D system for green building roofs

A novel transparent roof which is made of solid CPC (Compound Parabolic Concentrator) PV/T/D (Photovoltaic/Thermal/Day lighting) system is presented. It combines the solar PV/T/D system with green building design. The PV/T/D system can achieve excellent light control at noon and adjust the thermal environment in the building, such that high efficiency utilization of solar energy could be achieved in modern architecture. This kind of roof can increase the visual comfort for building occupants; it can also avoid the building interior from overheating and dazzling at noon which is caused by direct sunlight through transparent roof. Optical simulation software is used to track the light path in different incidence angles. CFD (Computational Fluid Dynamics) simulation and steady state experiment have been taken to investigate the thermal characteristic of PV/T/D device. Finally, the PV/T/D experimental system was built; and the PV efficiency, light transmittance and air heating power of the system are tested under real sky conditions.

Hubungan Kepadatan Hunian dan Kualitas Fisik Rumah Desa Penda Asam Barito Selatan

Abstract: Residential density and housis physical quality in the Penda Asam Village of district South Barito 2014. A house that doesn’t meet the physical requirements can cause immune deficiencies so that the diseases so easily affected. This research aims to know the physical quality’s house and residential density in the Penda Asam’s village of South hamlet subdistrict South Barito regency 2014. This research design was cross sectional with observation method, and measurement. The research population is 195 head of family with 51 houses sample. Data analysis was based on Kepmenkes RI No.829/Menkes/SK/VII/1999 about health housing requirements. The research result showed physical quality’s house: the kind of zinc roof as many as 35 houses 68,6% and 11,8% multiroof. The lighting eligible as 74,5%; ineligible as 25,5%, the temperature eligible as 7,8%; ineligible as 92,2%, the humidity eligible as 17,6%; ineligible as 82,4%, the residential density not solid’s category as 45%; solid’s category as 55%. The effort to overcome the problem: open the window in the morning, keep the ventilation system so that air circulation can be fluently, do reforestation around the house so that the environment condition becomes cool. Keywords: Residential Density, House Physical (the kind of roof; lighting; temperature; humidity)

Evaluación científico-técnica de la Ley General para el Control del Tabaco de México

The General Law for Tobacco Control, signed in February 2008, aims to protect the Mexican population against the negative effects associated with tobacco consumption and to guarantee the non-smoker's rights to live and relate in 100% smoke-free environments. The Law supports the development of smoke-free areas, but it also allows for indoor smoking areas. The present essay examines the Law and its Rule of Procedure, article by article, evaluating its capability to assure the protection of the population against the effects of environmental tobacco smoke. The analysis reveals conceptual and operative important imprecision, but mainly, discusses in detail the reasons why indoor smoking areas represent a health risk for the population. It concludes that the Law must be reformed, eliminating the provision of indoor smoking areas, any kind of roof in outdoor smoking areas and establishing a minimum distance between these areas and the 100% smoke-free environments.

Influence of Heating on Snow Sliding Characteristics of Resin-Coated Roofs

Five kinds of roofs were prepared and snow sliding characteristics for each roofs were observed from January 8th, 1986 to March 6th, 1986. The results obtained in this study were as follows:(1) On roofs without a heater, snow sliding occurred at the temperature above -2°C. The roof coated with the resin including high fulorine content was most effective for snow sliding, but the maximum snow weight accumulated on the roof reached 53kg/m2.(2) On roofs with a heater, it was found that snow sliding occurred in small blocks.

Catches in pitfall traps in relation to mean densities of carabid beetles

Based on continuous pitfall catches summed over the whole activity period for the carabid beetles Pterostichus versicolor Sturm and Calathus melanocephalus L., a satisfactorily linear relationship is presented between the mean densities in several habitats and in different years and the numbers of beetles trapped. This means that with the help of continuous pitfall sampling a reliable relative measure of the sizes of carabid populations can be obtained.Simulation experiments show that for individuals of P. versicolor the distances covered each day should be represented by strips of some width instead of by lines to obtain numbers trapped that equal the field data. The influence on numbers trapped of the high mobility of beetles in unfavorable habitats is probably not significant. Simulation experiments with C. melanocephalus indicate that a much lower capture efficiency than for P. versicolor has to be programmed to fit the simulation results with the field data.The catch from different types of pitfalls is not always proportional to trap perimeter due to different vegetation cover of the immediate trap surroundings and to different kinds of roofs placed over the pitfalls. For the same species the capture efficiency of a pitfall can also change throughout the season.Simulation experiments show that the number and shape of the pitfalls need not influence the catches, provided that the traps keep the same total perimeter and are broadly spaced.Remodelling of some data from the literature reveals that the linear relationship between mean densities and year-catches in pitfalls is probably a general one among carabid species. This leads to the hypothesis that carabid beetles have to work through a fixed reproductive program each year by means of an almost constant total amount of locomotory activity which is realized step by step during spells of suitable weather.Some recommendations are given for intraspecific and interspecific comparisons of pitfall catches between sites and years.