Search

Monitoring of powered roof supports is an area for research. External factors have a significant impact on the operation of powered support in a longwall excavation, therefore the use of solutions that will counteract these factors is an area for improvement. The article presents studies related to the adaptation of the measuring and recording system for the geometric parameters of the section and its compatibility with the powered roof support. Each of the presented stages consisted of a series of analyses based on computer simulations using the finite element method (FEM), as well as bench tests and real-life tests. The tests included defining the geometric parameters of the powered roof support's work in the test site and the mining wall. These studies allowed for the development of guidelines for the monitoring system. The results and analysis allowed for the formulation of two crucial conclusions. The use of a measuring system is a tool that allows monitoring the geometric parameters of the powered roof support during the coal mining process. The system monitors the transverse and longitudinal inclinations of the canopy, base floor, shield and the lemniscate, as well as the operating height of the support. The structure of the powered support can also be improved to improve operational safety by installing innovative mounting brackets for the monitoring system. The holders will allow for safer and more precise installation of the sensors and will make calibration of the system easier. [ABSTRACT FROM AUTHOR]

This study aimed to assess the quality of harvested rainwater from two (aluminum and corrugated zinc) commonly used roof materials in several urban and rural parts of Africa, and particularly in Nigeria for potable use, and to identify and select appropriate water quality indicator sensitive to variations in response to roof types and precipitation sampling time regimes. A total of 36 samples (first-flush and post-flush) were taken from two different urban residential roofs during six rainfall events, within the months of June (3events) and July (3events), and analyzed for selected water quality parameters. The results showed that concentrations were far below recommended guidelines (WHO and NSDWQ). However, concentration levels in First-flush samples for the two roofs were relatively higher than Post-flush. This implies that quality improves with initial roof washoff as traditionally practiced. Results also showed that sampling (interval) time had significant influence on quality parameters than roof material. Multivariate statistical tool was employed to identify a sensitive quality indicator. Factor analysis (FA) was used to group parameters into significant factors that explained over 72% of variations in water quality parameters. Discriminant analysis identified Sulphate and Chloride as the most sensitive parameters for residential roof harvested rainwater, and therefore, may be applied for water quality monitoring in the region. [ABSTRACT FROM AUTHOR]

To address the issues of excessive heat loss from the roofs of multi-span greenhouses and high energy consumption for heating during winter production, we propose an approach for the external insulation of the roof of multi-span glass greenhouses and have developed an external insulation system (EIS) to practice this approach. The system achieved full coverage of the greenhouse roof through mechanized unfurling and furling of external thermal blankets, thereby achieving energy-saving insulation. This paper describes the overall design and working method of the EIS, providing detailed design and structural parameters for critical components such as the traction rope transmission mechanism and the rail-type sealing structure. Through a system verification experiment, the specifications of the traction rope were determined and the rationality of the EIS's thermal blanket unfurling and furling time was confirmed. An insulation performance experiment indicated that the average heat flux of the greenhouse roof covered with the external thermal blanket over 14 continuous nights was 54.2 W/m2, compared with 198.6 W/m2 for a single-layer glass roof. Covering the roof with the external thermal blanket reduced heat loss from the glass roof by 72.7%. The average heat flux of the roof of the Venlo-type multi-span greenhouse with double-layer internal insulation was 99.9 W/m2 during the same period, indicating that the heat loss from the roof using external insulation was only 50.3%. This study provides a novel thermal insulation approach and an energy-saving system for multi-span greenhouses. [ABSTRACT FROM AUTHOR]

Longwall powered roof supports have been used to protect mine workings for over 70 years. Their design and especially technological parameters, have evolved significantly. These changes were dictated, on the one hand, by the need to meet the growing functional requirements and, on the other hand, by the increasingly difficult natural operating conditions. Conditions of interaction of the roof support with the surrounding rocks, which determine not only operational safety, also impact of the structural form of the roof support and its assemblies. Powered roof support is an important part of the longwall system, not only separating the working area of the longwall panel from the rocks forming the roof and the caving, but also ensuring the advance of the longwall system as the longwall advances and realization of each operation of the technological cycle. The need to meet these functional requirements means that technical factors such as: the method of managing the roof of the working, height of the wall, its inclination, the method of mining and the planned advancement of the wall significantly impacts the structural form and technical parameters of the roof support. The main purpose of this article is to present the method of modernization of a gob shield which is a part a powered longwall roof support. [ABSTRACT FROM AUTHOR]

Forensic engineers are commonly asked to develop conceptual scopes of repair as part of their work. Many factors impact these recommendations, including building codes, construction feasibility, manufacturer assessment, and installation requirements. In addition, the conditions present on and within the existing roof surfaces can limit the repairability of a commercial roof assembly such that removal and replacement of the entire roof section is the appropriate or only feasible repair option. This paper will focus on common limitations to be considered when developing a conceptual scope of repair for common commercial roof systems, including single-ply membranes, built-up roofing, metal panel roofing, spray polyurethane foam roofing, and the application/maintenance of roof coatings. It will also discuss an assessment methodology that can assist in developing a broader understanding of the condition of the roof surfaces. [ABSTRACT FROM AUTHOR]

There is a trend to roof over the courtyards of historical palaces and similar great buildings with an eye to conservation or to expanding their range of functions. This tendency is being popularized by major architects and barely a voice is raised against it. However, from the viewpoint of theory and heritage, such actions are not to be recommended. In line with some international documents on cultural heritage, several architectural, perceptual and functional arguments show that, in order to preserve the cultural authenticity of courtyards, it would be advisable to avoid covering them. A courtyard is by definition an open space. Covering it, even with an apparently harmless glazed roof, radically affects its architectural essence and how it is experienced. Hence, such projects should not be accepted in a generalized and uncritical manner. It is best for courtyards to be left as courtyards, not as rooms with skylights.

Ningbo's seaport hydrogen refueling station was used as the research object. The effects of different leakage angles, wind direction, roof shape, leakage hole diameters, temperature, and humidity on the diffusion of hydrogen leakage were studied by numerical simulation. The influence of leakage angle on hydrogen leakage is mainly reflected in the presence or absence of obstacles. The volume of the flammable hydrogen cloud was reduced by 31.16%, and the volume of the hazardous hydrogen cloud was reduced by 63.22% when there was no obstacle. The wind direction can significantly impact hydrogen leakage, with downwind and sidewind accelerating hydrogen discharge and reducing the risk. At the same time, headwind significantly increases the volume of the flammable hydrogen cloud. Compared with no wind, the volume of the flammable hydrogen cloud increased by 71.73% when headwind, but the volume of the hazardous hydrogen cloud decreased by 24.00%. If hydrogen shows signs of accumulation under the roof, the sloping roof can effectively reduce the hydrogen concentration under the roof and accelerate the hydrogen discharge. When the leakage angle θ = 90°, the sloping roof reduced the volume of the flammable hydrogen cloud by 11.74%. The leakage process was similar for different leak hole diameters in the no wind condition. The inverse of the molar fraction of hydrogen on the jet centerline was linearly related to the dimensionless axial distance of the jet in different cases. Using a least squares fit, the decay rate was obtained as 0.0039. In contrast, temperature and humidity have almost no effect on hydrogen diffusion. Hydrogen tends to accumulate on the lower surface of the roof, near the roof pillars and the hydrogen dispenser. In this paper, a set of hydrogen detector layout schemes was developed, and the alarm success rate was verified to be 83.33%. •CFD numerical model for hydrogen refueling station at seaport is developed. •Pseudo-diameter model is used to describe simplified high-pressure hydrogen jet. •Effects of roof, leakage angles and wind on hydrogen diffusion are studied. •Recommendations on hydrogen detector layout are given based on parametric study. [ABSTRACT FROM AUTHOR]

Copyright of CienciAmérica is the property of Revista Cienciamerica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The installation of photovoltaic (PV) panels on building roofs has seen a significant increase in recent years due to the rising cost of conventional energy sources. This shift towards renewable energy sources has been driven by the urgent need to mitigate the effects of climate change. PV applications is one of the most sustainable and cleanest sources of renewable energy, producing no greenhouse gas emissions during operation. By reducing reliance on fossil fuels, the use of PV panels can help to reduce carbon emissions and lower the overall carbon footprint of buildings. In addition to the environmental benefits, the installation of PV panels can also provide economic benefits, such as reduced energy costs and increased property value. In the past, installations were mostly made in the direction of the south, but now the roofs of the buildings facing west, east, and even north are also considered for PV panel installations. In this study, a grid-connected PV system with an installed power of 148 kWp at the Konya Technical University (KTUN) campus is modeled by PVsyst software. The PV systems' performance on building roofs oriented in different geographical directions (north, south, east, and west) with a 30° fixed tilt angle was investigated. In the modeling, the solar irradiation coming to the surfaces of the PV panels, electricity production values, performance ratios, and their economic feasibility were calculated. The highest effective irradiation value on the panel surface was obtained from the system facing south, found as 1964.4 kWh/m². It is 20.77%, 22.87%, and 73.48% higher than the solar irradiation obtained at -90°, +90°, and 180° azimuth angles, respectively. It is concluded that the electricity generation amounts of PV systems highly depend on the azimuth angle. Similarly, the highest annual electricity production was obtained from the system installed in the 0° azimuth angle found as 254.77 MWh. The annual total electricity generation is 19.66%, 22.55%, and 69.41% higher in systems modeled toward the east, west, and north, respectively. Performance ratio, defined as the ratio of radiation coming to the panel surface and the electricity produced, has relative values between 0.843 and 0.862 for four different azimuth angles. Furthermore, as an economic analysis, the Basic Payback Period (BPP) of the projects was found as 6.92 years, 4.08 years, 4.88 years, and 5.00 years for the systems modeled in the north, south, east, and west directions, respectively. It can be concluded that the most suitable orientation is south, and the other two directions, east, and west, can also be considered feasible. [ABSTRACT FROM AUTHOR]

Detecting asbestos-containing roofs has been of great interest in the past few years as the substance negatively affects human health and the environment. Different remote sensing data have been successfully used for this purpose. However, RGB and thermal data have yet to be investigated. This study aims to investigate the classification of asbestos-containing roofs using RGB and airborne thermal data and state-of-the-art machine learning (ML) classification techniques. With the rapid development of ML reflected in this study, we evaluate three classifiers: Random Forest (RF), Support Vector Machine (SVM), and eXtreme Gradient Boosting (XGBoost). We have used several image enhancement techniques to produce additional bands to improve the classification results. For feature selection, we used the Boruta technique; based on the results, we have constructed four different variations of the dataset. The results showed that the most important features for asbestos-containing roof detection were the investigated spectral indices in this study. From a ML point of view, SVM outperformed RF and XGBoost in the dataset using only the spectral indices, with a balanced accuracy of 0.93. Our results showed that RGB bands could produce as accurate results as the multispectral and hyperspectral data with the addition of spectral indices. [ABSTRACT FROM AUTHOR]

The caving characteristics of the goaf significantly impact the mining stability of the working face. The coal-forming environment of the steeply dipping coal seam is complex. After mining, the caving rock mass rolls to the lower part of the working face due to gravity, and the caving compaction characteristics of the working face are different from those of the flat and gently inclined working face, taking Huainan Xinji No. 2 Mine 211112 high-angle composite roof working face large-area gang roof fall area as the engineering background. To safely pass through a large roof fall area, a FLAC3D numerical simulation method considering the goaf's compaction effect and the excavation's additional damage is proposed. The Weibull distribution function is introduced to modify the elastic modulus parameters of the rock mass after excavation, which more accurately reflects the damage process of the rock mass after hole. Based on the goaf compaction theory, the elastic model is developed for the second time, and the accurate simulation of the caving rock mass is realized. On this basis, the proposed numerical simulation method is used to simulate the large-area roof caving of the large-angle working face, a scheme to control the stability of the working face by using the paste filling technology is proposed, and the material parameters of the filling body are determined. The research results show that when the water-cement ratio of the backfill is 3 : 1, the simulation and field trial results are good, and the safe and efficient mining of the large-angle composite roof working face is realized, which verifies the feasibility and correctness of the coupled simulation method. At the same time, the research results can provide a reference for controlling the roof fall area of the working face with a large inclination angle. [ABSTRACT FROM AUTHOR]

Recently, Phase Change Materials (PCM) have become more prevalent in improving buildings' thermal management. The relative location of the PCM layer is a valuable measure for assessing the thermal performance of building envelopes, in addition to meteorological circumstances and PCM qualities. The optimum air layers between the PCM layer and roof may significantly reduce energy consumption in buildings. In this regard, the influence of air gap layer thickness on the thermal performance of a PCM (HS 29) integrated roof of the test room is investigated experimentally. Experiments are carried out for an unconditioned test room located on the terrace of a laboratory in Surat, India, considering various air layer thickness values (0, 2, 4, and 6 cm) and a fixed PCM layer thickness. Different configurations within the research, including no- PCM and PCM with 0, 2, 4, and 6 cm air layer thickness, are investigated for the effects of diurnal change in room temperature. Results are evaluated based on the peak value, valley value temperatures of different roof layers, and an index (MKR, Measure of Key Response). It is observed that the maximum temperature difference between the PCM-integrated test room and the non-PCM test room is 4 °C to 7 °C. Results showed that, with a higher MKR index of 8.83, a PCM-integrated roof with a 2 cm air layer thickness could reduce the diurnal room temperature variations compared with the non-PCM test room. This conclusion from the current research demonstrates the significance of an air layer provided between the PCM layer and the roof of the building. [ABSTRACT FROM AUTHOR]

Copyright of Acta Scientiarum Polonorum: Architectura is the property of Wydawnictwo SGGW and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the domestic sector, buildings contribute to about 55% of the total energy consumption for space heating and cooling. In this study, an experiment was carried out using a square shape building prototype made up of laminated plywood with Reinforced Cement Concrete (RCC) roof. Surface treatment of four types of reflective paints was applied on the RCC roof slab. Their performance was monitored in the summer season (April and May). Based on the peak temperature of interior and exterior roof layers, several important parameters, such as temperature, indoor thermal amplitude, time lag, decrement factor, thermal damping, thermal performance index, peak degree hours and thermal performance of each roof slab, were analysed. The application of cool roofs (CR-1, CR-2, CR-3, and CR-4) shows a significant reduction in indoor temperature (2.1°C–3.2°C), and indoor thermal amplitude (16.10%–27.94%) compared to a standard RCC roof. The drops in peak temperature of exterior and interior roof layers were 4.8°C–6.8°C and 3.9°C–6.3°C, respectively. A significant improvement was achieved in time lag and decrement factor (3–4 h more than the reinforced concrete roof), with energy savings varying from 10.58% to 13.73%. [ABSTRACT FROM AUTHOR]

Cycladic architecture has been the focus of archaeological, ethnographic and architectural studies, which have produced significant knowledge about the islands’ built environment. Despite the number of published studies, there is little archaeological evidence related to the parts of buildings, such as roofs and second storeys made of degradable materials (i.e. sediments and organic materials), which are nowadays lost or poorly preserved. On the other hand, ethnographic and architectural studies lack the details of local variabilities regarding the construction of the fragile architectural components. This geo-ethnoarchaeological study applied a high-resolution analysis including soil micromorphology and phytoliths to the roofs of abandoned traditional farmsteads (mitata) on two islands, Kato Kouphonisi and Naxos in the Cyclades, supplemented by oral testimonies from elderly residents and published ethnographic information. This was combined with comparable microstratigraphic analysis conducted on sediments from the nearby Early Bronze Age site of Dhaskalio, Keros. The analysis of abandoned farmsteads generated a high-resolution dataset of micro-characteristics linked to known practices and materials of traditional roof construction. These were then traced into our archaeological samples to detect similar features and ultimately improve on contextual interpretation beyond field observations. We therefore suggest that this geo-ethnoarchaeological approach is useful in the identification of roof sediments in archaeological deposits, enhancing the ability to recognise such events in the field and demonstrating that a signature of collapse events can be defined. [ABSTRACT FROM AUTHOR]

Abstract Background In rural sub-Saharan Africa, thatch roofs are being replaced by metal roofs. Metal roofing, however, increases indoor temperatures above human comfort levels, and thus makes it more likely that residents will not use an insecticide-treated bed net (ITN) at night. Whether the colour of a metal roof affects indoor temperature and human comfort was assessed. Methods Two identical, experimental houses were constructed with metal roofs in rural Gambia. Roof types were: (1) original bare-metal, (2) painted with red oxide primer or (3) white gloss, to reflect solar radiation. Pairwise comparisons were run in six, five-night blocks during the malaria season 2018. Indoor climate was measured in each house and multivariate analysis used to compare indoor temperatures during the day and night. Results From 21.00 to 23.59 h, when most residents decide whether to use an ITN or not, the indoor temperature of a house with a bare metal roof was 31.5 °C (95% CI 31.2–31.8 °C), a red roof, 30.3 °C (95% CI 30.0–30.6) and a white roof, 29.8 °C (95% CI 29.4–30.1). During the same period, red-roofed houses were 1.23 °C cooler (95% CI 1.22–1.23) and white roofs 1.74 °C cooler (95% CI 1.70–1.79) than bare-metal roofed houses (p

• Examines the effect of financial inclusion on roof quality among Chilean slums. • Utilizes satellite data to provide a method for assessing permanent materials among slum roofs. • Presents empirical evidence indicating a reduction in transaction costs as a relevant benefit resulting from financial inclusion for families residing in slums. • Identifies a positive effect of financial inclusion on roof quality among Chilean slums. • Provides evidence supporting entrepreneurship activities as a potential transmission channel through which financial inclusion affects slum-roof quality. Although not all residents of slums are necessarily poor, and conversely, not all low-income individuals live in slums, housing precarity is a distinctive feature of these communities. This paper examines the relationship between financial inclusion and roof quality improvements for individuals living in slum settlements in Chile. We use satellite images to measure the quality of dwelling roofs as well as the CajaVecina initiative to measure the level of financial inclusion of the families that live there. Our results reveal that a higher level of financial inclusion results in an expanded presence of permanent-material roofs within slums. Moreover, we provide evidence that financial inclusion encourages self-employment activities among low-income individuals which is evidence of a transmission channel for the effect studied. [ABSTRACT FROM AUTHOR]

In underground engineering, the deformation and failure process of the surrounding rock of the roadway is always accompanied by the occurrence of energy. The study of the energy distribution law of the surrounding rock of the roadway plays an important role in its stability. This paper first theoretically analyzes the stress and energy distribution law of the surrounding rock of the roadway, then with the help of numerical simulation method, combined with the existing physical and mechanical parameters, based on the existing support parameters of Dongrong No. 2 Mine, gradually compares and analyzes the distribution of vertical stress and energy under the three support methods of no support, original support, and combined support, and the results found that the vertical stress distribution law under the three support methods is basically the same. High-stress areas appear on the two ribs of the roadway, and low-stress areas appear on the roof and floor. The range of high-stress areas from no support to combined support continues to decrease and becomes more evenly distributed. The energy distribution pattern is basically the same. The overall energy of the coal seam is high. There are high-energy areas at 2 m left and right of the roadway, and the roof and floor energy of the roadway is the smallest. The low energy area extends 5 m up and down, respectively. The range of high-energy areas from no support to combined support is shrinking, and the energy distribution is more uniform. [ABSTRACT FROM AUTHOR]

The substantial increase in extreme weather events in recent decades, especially hurricanes and tropical cyclones, constitutes a threat to the Caribbean region. The impact of these phenomena on houses and buildings with light roofs has increased considerably in recent years. The objective of this research is to describe a procedure that allows the numerical simulation of light metal roofs in the aspect of static and dynamic loads typical of extreme winds, in order to obtain criteria about the limit stresses and deformations to which they are subjected, which facilitate the decision-making process. Systems analysis and synthesis methods were used, as well as finite element modeling and simulation. The dynamic analysis of the wind loads made it possible to simulate the real behavior of the light roofs. It was shown that the highest stress values are concentrated in the area near the holes in the roof, constituting the weakest point where the failure of the metallic light roof begins. The results show that the proposed procedure facilitates decision making in the search for constructive solutions that minimize these effects. [ABSTRACT FROM AUTHOR]

The article analyses the appearance of this type of vertical development, known as mansardization and mansarda is almost exclusively used to refer to the internal roof space, rather than the structure itself. It mentions mansard roof was popularized by the seventeenth-century French architect François Mansart. It also mentions architectural features of the mansard can be seen in some of St Petersburg, Russia's early historical buildings.

Energy efficient is becoming a significant subject to investigate within the Architecture Engineering and Construction (AEC), as a result of the expanding heating and energy usage problem. Lack of interoperability has been identified as a hurdle to increased efficiency in the AEC. In order to fulfil the expanding demands around the world, the energy analysis must be incorporated into the building's planning section. Predicting a building's energy use and establishing an energy-saving life and style are both required. To conduct an energy study of a G+3 residential structure, the article uses Autodesk (BIM) capabilities. The goals of this project are to find BIM energy analysis into calculating a building's energy consumption, as well as to conclude the life cycle cost and energy cost over time, in same building. This study's primary focus is on roof materials and alternatives accomplished with the use of Autodesk Revit software and Green Building Studio, a cloud-based energy analysis application. [ABSTRACT FROM AUTHOR]

Copyright of Studia Academica Šumenensia is the property of Konstantin Preslavsky University of Shumen and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The crown-post roof appeared in England in the second half of the thirteenth century and persisted until the early sixteenth century in the south-east of England. Rafter holes are found in these roofs near to the feet of the rafters on their lower faces. They are blind holes typically 75 mm to 100 mm deep by about 25 mm in diameter. Various theories have been put forward over the years to explain their function. This paper reviews the evidence found on the rafters and integrates it into a revision of one of the earlier theories which suggested that rafter holes formed part of a jig or templet. This jig was used to ensure that the collars were at the correct height relative to the crown plate (or collar purlin). These ideas have been applied in the prefabrication of a new crown-post roof. Evidence is also presented showing how the practice of using jigs to help prefabricate rafter cross-frames may also have been applied to some other roof types such as scissor-braced and side-purlin roofs, in south-east England. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering Management / Gongcheng Guanli Xuebao is the property of Journal of Engineering Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The roof is the component of the envelope more subjected to climatic excitations, and it contributes to a significant part of the total building's cooling load in hot climates. Therefore, the thermal optimization of hollow concrete blocks for roofing can considerably reduce the enormous energy consumption used for cooling buildings. For this purpose, the thermal inertia of different configurations of roofs built with traditional concrete blocks used in Morocco with three and six cavities was studied numerically. First, a two-dimensional coupled heat transfer by conduction, convection, and radiation was investigated in the steady-state using the Galerkin finite element method to generate an equivalent homogeneous monolayer block with similar thermal behaviour to the original hollow-block roof. After that, the transient heat conduction equation under real thermal solicitations is solved using a numerical inversion of the Laplace domain solution by utilizing the De Hoog algorithm to evaluate the dynamic thermal characteristics of the roofs. The results report that the emissivity and inside combined convection and radiation heat transfer coefficients significantly impact the roof's thermal inertia. In addition, it is shown that the configuration based on using a low emissivity coating and inserting an insulating material between the outer surface of the block and the slab could reduce the total thermal load over 24-hours by about 93.1% compared to the traditional configuration, which is beneficial to minimize the energy consumption used for cooling buildings.