Roof Types Research Articles

PHYSIOLOGICAL RESPONSES OF FEMALE BEEF CATTLE AGAINST PEATLAND MICROCLIMATE STRESS IN CENTRAL KALIMANTAN

This study aimed to evaluate the physiological response of female beef cattle to peatland microclimate stress in Central Kalimantan. This study used direct observation on small holder beef cattle farm. Microclimate data on 41 units cattle barns and physiological parameters of female cattle were collected in the morning, at noon and in the afternoon. The physiological parameter measurements involved 215 female beef cattle, consisting of 119 Bali and 96 crossbred cattle with different physiological stages including pregnant cows, lactating cows, dry cows, heifers and calves. The microclimate condition within cattle barns on peatland of Central Kalimantan is not the comfort zone for beef cattle. It is characterized by high air temperature and relative humidity, and low wind speed, which result in high temperature humidity index (THI). The barn with gable roof type and asbestos materials gave the lowest THI. This Microclimate caused heat stress to beef cattle reared on the peatlands, indicated by the high rectal temperature, heart rate, respiratory rate, and heat tolerance coefficient, although it was still categorized as mild to moderate stress. Bali cattle showed better physiological responses to microclimate stress than crossbred cattle. Pregnant crossbred cows were the most susceptible to peatland microclimate stress.

On the identification of most appropriate green roof types for urbanized cities using multi-tier decision analysis: A case study of Istanbul, Turkey

Green roofs (GRs) have gained considerable attention in recent years as a sustainable solution for densely urbanized cities to mitigate the negative impacts of urbanization on the environment. Hence, this research proposed a hybrid multi-criteria decision-making scheme aiming to determine the best-matched GR formation for metropolitan city of Istanbul. Therefore, fuzzy AHP and TOPSIS were adopted for weighting a total of 16 criteria and performing binary prioritization of intensive GRs (IGRs) and extensive GRs (EGRs) for the focalized region, respectively. Two GR types were examined based on four major dimensions, i.e., financial, technical, knowledge, and environmental aspects. The results highlighted the vitality of financial (35.01%) and environmental (34.91%) facets, followed by the technical (21.83%) dimension, whereas knowledge (8.24%) was the least significant aspect. Also, initial and operational costs (global weight: 17.37%) and stormwater retention capacity (global weight: 16.98%) outperformed their counterparts. Combining the criteria weight computed and the average scores of each factor with regard to the city further illustrated that EGR (CCi: 0.7442) was found as the optimal GR configuration for Istanbul. The key findings of this research aimed to contribute to the growing GR literature by exploring the paradigms regarding the sustainability and resilience of urbanized cities.

Input data requirements for daylight simulations in urban densifications

One of the biggest challenges in urban densifications is securing adequate daylight access. This study examines the potential of using semantic 3D city models as input to daylight simulations. It is focusing on investigating input data requirements to these simulations from a geodata, 3D city model specification and measuring guideline perspective. To achieve this, geodata simulation input requirements for the most common daylight metrics are documented. Next, 3D city model data from two Swedish municipalities along with 3D data constructed by ourselves in CAD- and GIS-environments are utilized to explore the impact of using 3D city models of different levels of detail (LOD) and positional accuracy in daylight simulations linked to Swedish and European laws and recommendations. Similarly, the measuring guidelines and 3D city model specification requirements related to balconies and other façade accessories are also evaluated along with the utilization of façade reflectance properties and colour. It is found that LOD1 is sufficient for the obstruction angle metric for most roof types but for e.g., gabled roofs LOD2 should be used. A positional accuracy on a decimetre-level is accurate enough for the aforementioned metric. Daylight factor simulations require that balconies and façade accessories protruding more than a couple of decimetres must be represented in the 3D city model along with information on façade material and colour. The outcome of the study is expressed in the form of a list of recommendations for the creation of national profiles of 3D city models supporting daylight simulations.

Modeling green roofs in tropical housing to support micro-scale food security

Research on green roofs in tropical residential buildings has the opportunity to be a substitute for productive green spaces. This research implements several vegetable plants as building roof covering elements, i.e., peanut, eggplant, chili, and tomato. Experimental research was applied jointly for six months on four types of vegetables on a green roof covering an area of sixteen square meters. The green roof model consists of a green roof model on concrete and corrugated zinc through a floating technique as a roof model engineering. The aim of this research is to examine the roof as a substitute for green space in buildings. The results showed that the four types of vegetables could grow well on both roof models, both types of green roof have the opportunity to be implemented in residential areas, resulting in fruit that could be consumed on a household micro scale.

Air Temperature Variations Due to Different Roofs and Their Impact on Energy Consumption and Emissions: Mexicali University Campus Case Study

Roof surfaces on which air conditioning equipment is installed cause significant air temperature increases around the condensers due to roof thermal properties, resulting in excess electrical energy consumption and greenhouse gas (GHG) emissions. An experiment to quantify such excesses during the summer was conducted at a university campus in Mexicali, Mexico. The air temperatures and surface temperatures for three types of roofs were recorded. Temperatures (condenser inlet air temperatures) were used as the input data to a priori estimate the electrical consumption of a 5-ton A/C equipment working over these different roofs. Temperatures recorded by a nearby meteorological station were used as a reference. The results indicate a differential of up to 4.81 °C, resulting in an excess of electricity consumption of 5.55 kWh and an additional 3.9 kg of CO2 emissions, representing an 8.2% energy surplus and differences of up to 2.1% in electricity consumption provoked by microclimate.

Parametric Assessment of Building Heating Demand for Different Levels of Details and User Comfort Levels: A Case Study in London, UK

The Level of Detail (LoD), a parameter used to define the information contained in building models, is an important factor to consider in modeling building energy at the urban scale. In this research, we conducted a parametric study regarding the data requirements for the estimation of the annual residential heat demand in London. More particularly, the requirement of the observation of the actual roof type (LoD2) and the window-to-wall ratio (LoD3) was examined in two different case study areas. Meanwhile, an adaptive comfort level study was implemented using LoD5 models, and its results were assessed holistically with the heat demand to reveal the energy performance of the buildings. The results showed that there was a minor difference in the upgrade of a lower to higher LoD regarding these parameters. At an urban scale, the energy demand of buildings could be estimated using an assumption of archetypes and building ages. However, with a scalable parametric script developed in places, models with a high LoD could provide more detailed insights in the energy performance assessment without generating excessive workload.

Acid Mine Drainage Discrimination Using Very High Resolution Imagery Obtained by Unmanned Aerial Vehicle in a Stone Coal Mining Area

Mining of mineral resources exposes various minerals to oxidizing environments, especially sulfide minerals, which are decomposed by water after oxidation and make the water in the mine area acidic. Acid mine drainage (AMD) from mining can pollute surrounding rivers and lakes, causing serious ecological problems. Compared with traditional field surveys, unmanned aerial vehicle (UAV) technology has advantages in terms of real-time imagery, security, and image accuracy. UAV technology can compensate for the shortcomings of traditional technology in mine environmental surveys and effectively improve the implementat ion efficiency of the work. UAV technology has gradually become one of the important ways of mine environmental monitoring. In this study, a UAV aerial photography system equipped with a Red, Green, Blue (RGB) camera collected very-high-resolution images of the stone coal mining area in Ziyang County, northwest China, and classified the very-high-resolution images by support vector machine (SVM), random forest (RF), and U-Net methods, and detected the distribution of five types of land cover, including AMD, roof, water, vegetation, and bare land. Finally, the accuracy of the recognition results was evaluated based on the land-cover map using the confusion matrix. The recognition accuracy of AMD using the U-Net method is significantly better than that of SVM and RF traditional machine-learning methods. The results showed that a UAV aerial photography system equipped with an RGB camera and the depth neural network algorithm could be combined for the competent detection of mine environmental problems.

A STUDY ON TRADITIONAL HOUSES OF LAFTAN VILLAGE IN FARAH PROVINCE, AFGHANISTAN

This study examines the features of the traditional houses of Laftan village in Farah Province, Western Afghanistan. The composition of the Laftan village was found to be strongly related to the local climate, topography, and the mosques as the center of the community. All the houses in the village are one-story buildings constructed with pakhsa (pressed mud) wall and domical vault roofs of sun-dried bricks. The plans, cooling systems, and roof types of houses depend on the age of the houses.

Typology of Malay Traditional Building Construction Case Study: Bawi Malay House In Kampung Empat Balai, Kampar

Kampung Empat Balai is one of the old villages in Kuok District, Kampar Regency. The kampung comprises traditional Malay houses as cultural heritages that urge to preserve. The house has a unique roof shape and carvings pattern. However, the house is endangering due to a lack of maintenance. This research has aimed to identify the construction of houses that belong to the Bawi ethnic group people. A qualitative descriptive approach has been carried out to investigate and analyse this Malay house. This research found that the Bawi's house has a curving roof type which is known as part of the Lotiok roof type. This stilt house has a structural system in the form of a series of line elements with non-rigid joints that bind each other using notches and pegs as a connection system that is anticipated for earthquakes. Materially, this Bawi'House uses wooden-based materials throughout its construction systems, such as floors, walls, columns, girder beams and roof trusses.Malay house; traditional construction; lontiok roof; wooden-based materials

The Stoa of Eumenes in Athens: Theoretical Restoration

Abstract The article offers a detailed discussion of the outline and all essential elements of the Stoa of Eumenes at Athens. It is a preliminary study for a more trustworthy reconstruction of this central architectural monument. Themes discussed are Doric columns, Ionic columns, Pergamene columns, double half-columns, examines the height of all architectural orders, prefabrication with Prokonnesian marble, and issues of transport, letters as mason marks, important horizontal dimensions, construction of the floor, particularities of the roof geison, roof type, diagonal beams, corner supports under diagonal beams, alterations on the stoa’s west end, and the reuse of geison blocks on the proskenion of the Dionysos Theater.

Green Spaces over a Roof or on the Ground, Does It Matter? The Perception of Ecosystem Services and Potential Restorative Effects

Cities are becoming more vulnerable to climate change and need appropriate adaptation measures. Previous studies demonstrated that urban green spaces provide multiple ecosystem services, improving the health and well-being of urban residents. Yet different urban green spaces provide different services—provisioning, regulating, cultural, or supporting ones. This work aims first to understand if urban green space users perceive the different supplies of provisioning and regulating services offered by different types of urban green spaces. Second, this work seeks to determine if green roof type conditions, as well as vegetation type and access, affect the users’ perceptions of the cultural ecosystem services. This work presents the results of an image-based online survey performed among 376 Portuguese undergraduate students between March and April 2021. The survey is based on nine alternative urban space designs, varying the roof access type and vegetation types. The results show a general preference for urban green spaces with more vegetation, regardless of the type of roof, and a general preference for green spaces with better accessibility. In addition, users’ preference for no-roof conditions appears to be linked to the abundance of vegetation and quality of urban design and not to awareness of an existing roof structure and its influence on the natural processes.

GR2L: A robust dual-layer green roof water balance model to assess multifunctionality aspects under climate variability

Urban blue-green infrastructures (BGIs) fulfill a variety of functions that enable cities to cope with climate change and additional urban anthropogenic pressures such as increasing population density, heat island effects, biodiversity loss, and progressive sealing of permeable surfaces. In the urban water cycle, BGIs can play an important role when it comes to both managing and mitigating the direct effects of ever-increasing periods of extended drought as well as the temporary excess of stormwater during and after heavy rainfall events. Although BGIs are multifunctional in principle, the individual infrastructure has to be designed and operated toward achieving a set of specific objectives, e.g., stormwater retention, infiltration, or storage for increased overall water resilience. In this study, we focus on green roofs as a key BGI for water resilient urban spaces. Green roofs have the advantage of unlocking underutilized roof space for urban water management and additional co-functions, avoiding additional urban land use conflicts at ground level. Green roofs are available in a multitude of design types based on the selection of vegetation, the make and thickness of the substrate layer, and the absence or presence of additional retention space. With GR2L, we present a robust dual-layer green roof water balance model that is able to cope with a variety of design aspects and was validated and calibrated using a data set of four green roof types with varying technical specifications and different vegetation cover. We used the calibrated models to assess how different green roof types operate under variable climatic conditions using meteo ensembles that consist of dry and wet years as well as a suite of randomly selected years. Calibration results indicate that a green roof factor (based on the classic crop factor) largely depending on the retention capacity of green roofs, makes the results widely applicable in planning. The results provide information on how green roof designs can be optimized for fulfilling a given set of water balance-driven multifunctionality objectives under varying climatic conditions and enabling an assessment of the performance of existing green roof designs against these conditions.

Experimental study on traditional timber-concrete hybrid house with different types of roofs using shake table

Buildings with different roofing systems possess different seismic performance during earthquake. Most of the traditional buildings are susceptible to earthquake disaster due to no seismic loading is considered in the design. In addition, irregular buildings have been proven to perform badly during earthquake events. Due to lack of investigations on asymmetrical timber-concrete hybrid building under earthquake loading, a ¼ of this type of building model was tested seismically using a unidirectional shake table. Four structural models with frequencies 3.85 Hz, 3.33 Hz, 2.70 Hz and 2.50 Hz varied using diagonal wooden braces and different roof materials namely heavy metal roof and clay roof tile. The models were subjected to El Centro ground motion excitations scaled to 0.08 g, 0.16 g, 0.24 g and 0.32 g PGA resembling 25%, 50%, 75% and 100% of the actual ground motion strength, respectively. Nine accelerometers and seven LVDTs were used to measure the seismic response of the models during shake table test for acceleration and displacement, respectively. Heavier roof material shows a different trend in the amplitudes across the maximum displacement time history, but a clear decrease in acceleration response for the roof level as compared with lighter roof material.

The Effects of Roadside Buildings Roof Shapes and Tree Plantings on the Vehicle Exhaust Gas Pollution Dispersion in the Urban Street

In this study, the effects of roadside building roof shapes and roadside tree plantings on the dispersion of vehicle exhaust gas pollution in the urban street have been carefully explored. Three typical roof shapes, i.e., flat, triangle and round shapes, are considered in the present work. Firstly, the numerical simulations of air pollution transport in the atmospheric turbulent boundary layer with/without the vegetation canopy have been performed using Computational Fluid Dynamics (CFD). Secondly, the mean flow patterns and the distribution of turbulent kinetic energy (TKE) are then examined. Finally, the concentrations of the air pollution have been carefully explored. It is found that the triangle roof could result in a lower concentration of air pollution in the street canyon. The existence of the roadside trees could decrease the air pollution concentration, although its influence is much weaker than the roof shape. It is also found that the concentration of air pollution is quite related to the flow pattern and TKE distribution. This study could provide helpful guidance on the urban planners on the design of the urban street in the future.

Comprehensive analysis of tropical rooftop PV project: A case study in nanning

Solar photovoltaic (PV) is favored by the market because of its clean and renewable characteristics. There are abundant solar resources in the tropical regions of China. It is important and necessary to carry out comprehensive analysis of rooftop PV projects for tropical regions for scientific policy-makings. Here, we select Nanning as a case study to analyze the optimal options for PV installation on different roof types and estimate the electricity generation potential of rooftop PVs and its additional returns. Our analysis shows that: 1) the annual optimal azimuth and tilt angle in Nanning are 245° and 32.5°, respectively; 2) the tilt angle in southwest orientation has more space for adjustment, while that in the opposite orientation should remain horizontal; 3) for flat roofs, being fixed at the annual optimal angles is practical, while for gable roofs, the east-west direction is favorable; 4) the total potential of rooftop PV projects in Nanning can reach 19.99 TWh/year, resolving 76.1% of the social electricity demand. This research is valuable for rooftop PV installation and optimization in the tropical regions of China, which also could provide reference for other regions.

Analysis of the 2017 Knysna fires disaster with emphasis on fire spread, home losses and the influence of vegetation and weather conditions: A South African case study

Wildland-Urban Interface (WUI) fires are becoming more common globally. However, most research has been focused on developed regions such as North America and Australia, exposing a lack of geographical diversity in the field. This paper presents an analysis of South Africa's largest WUI fire disaster, in terms of the number of structures lost and the economic losses, the 2017 Knysna fires. The data used in this report is based on aerial reconnaissance conducted immediately after the event, a geo-located database identifying homes that were destroyed, satellite imagery and site visits. The analysis includes the fire spread mechanisms, firebreak efficiency, the influence of roof and wall types, vegetation, and weather conditions. The Canadian Fire Weather Index (FWI) values on the day of ignition were unprecedented in the 1979–2021 period, the culmination of a clear multi-decadal trend towards greater fire weather risk. Due to the combination of severe medium-term drought and extreme fire weather conditions homes up to 1 km inside the WUI were destroyed. The high wind speeds allowed the fire to cross natural and artificial barriers such as rivers and highways, allowing the ignition of several secondary fires due to ember attacks. Construction materials and fire exposure, which is influenced by the presence of vegetation, affected home survivability. Combustible materials (thatch and timber) typically made homes more susceptible to fire damage. It was found that in the areas where more structures were affected the vegetation were dense, highly flammable stands of alien invasive vegetation.

Automatic 3D Building Reconstruction from OpenStreetMap and LiDAR Using Convolutional Neural Networks

This paper presents the implementation of an automatic method for the reconstruction of 3D building maps. The core innovation of the proposed method is the supplementation of OpenStreetMap data with LiDAR data to reconstruct 3D urban environments automatically. The only input of the method is the area that needs to be reconstructed, defined by the enclosing points in terms of the latitude and longitude. First, area data are requested in OpenStreetMap format. However, there are certain buildings and geometries that are not fully received in OpenStreetMap files, such as information on roof types or the heights of buildings. To complete the information that is missing in the OpenStreetMap data, LiDAR data are read directly and analyzed using a convolutional neural network. The proposed approach shows that a model can be obtained with only a few samples of roof images from an urban area in Spain, and is capable of inferring roofs in other urban areas of Spain as well as other countries that were not used to train the model. The results allow us to identify a mean of 75.57% for height data and a mean of 38.81% for roof data. The finally inferred data are added to the 3D urban model, resulting in detailed and accurate 3D building maps. This work shows that the neural network is able to detect buildings that are not present in OpenStreetMap for which in LiDAR data are available. In future work, it would be interesting to compare the results of the proposed method with other approaches for generating 3D models from OSM and LiDAR data, such as point cloud segmentation or voxel-based approaches. Another area for future research could be the use of data augmentation techniques to increase the size and robustness of the training dataset.

Effect of the CHS on Seismic Responses of the Single-Layer Spherical Reticulated Shell under Vertical Seismic Motions

Single-layer spherical reticulated shells are typical roof structures for the gymnasiums. The center-hung scoreboard (CHS) is large weight display device which is usually suspended on the roof of the gymnasium. The effect of the CHS on the dynamic characteristics and seismic responses of the single-layer spherical reticulated shell (SPRS) is not fully clear. In this paper, the effect of the CHS on the SPRS under vertical seismic action is investigated. Two kinds of FE models are built with Abaqus software, including the flexibly suspended model and the simplified model. In a simplified model, the CHS is simplified as four fixed masses on the four CHS suspension nodes. The dynamic explicit method is used for the seismic responses, and the Lanczos method is used for the dynamic characteristics. The influence of the CHS weight and the sling length of on dynamic characteristics and seismic responses are analysed. It turns out that in the flexibly suspended model, the first three vibration modes are free swing of the CHS, and the CHS weight and the sling length have a significant impact on the fourth and subsequent modes. The length of the sling has a large impact on some low-order frequencies, but has little impact on the high-order frequencies. Compared with the simplified model, the axial forces of some structural members and some nodal acceleration in the flexibly suspended model under vertical seismic motions would increase by as high as 523% and 564%, respectively. It turns out that the seismic responses of the SPRS would be underestimated if a simplified model is used for analysis. The region in the central of the SPRS, the hoop members of the SPRS, and the support platform are the most affected regions in terms of both axial force and nodal acceleration.

Experimental Study on Aerodynamic Forces of a Suspended Arch Roof

With the development of building materials, construction technology, and design concepts, suspended arched roofs (SARs) are becoming increasingly popular. The wind loads of arched roofs springing from ground level (ARSGL) and vaulted roofs on side walls (VRSW) have already been studied; however, the wind loads of SARs, which are very different from those of ARSGL or VRSW, have not received adequate attention. Based on the wind tunnel tests of a rigid model of an actual SAR design scheme, the mean value, root mean square (RMS) value, and most unfavorable value of the wind pressure coefficient and overall lift coefficient of this type of roof are analyzed. Furthermore, the influence of the buildings below or surrounding it is investigated and discussed. The test results indicate that the net wind pressure of the SAR is affected by the upper- and lower-surface wind pressures. Both the most unfavorable wind pressure (positive pressure) and suction (negative pressure) coefficients of the SAR are larger near the edge (arch foot) and smaller in the internal area. The maximum values of the most unfavorable pressure and suction coefficients of the tested SAR are 4.5 and 8.0, respectively, and these values are larger than those of ARSGL and VRSW. The buildings below cause airflow congestion under the SAR and eventually increase the net pressure coefficients near the windward edge of the SAR. The shielding effects of the surrounding buildings of the tested SAR reduce the wind pressure coefficient; however, the wind pressure in some areas of the tested SAR increases because of the narrow tube effects between surrounding buildings. The lift coefficient of the tested SAR significantly increases because of the presence of buildings below in some cases.

A Comparative Experimental Study of Green Roofs Based on Radiation Budget and Surface Energy Balance

One of the major benefits of a green roof is its thermal performance compared to a conventional concrete roof building; it maintains indoor temperatures under varying outdoor temperatures. In this study, data were collected from four newly built detached buildings with a bare concrete roof, a highly reflective roof, and two green roofs, respectively. The results showed that the green roofs lowered the maximum indoor temperature by 6.83? on average compared to a bare concrete roof building, which potentially saves a substantial amount of energy required for cooling buildings. The surface energy balance analysis using the flux profile method showed that the difference in ground heat flux depending on roof type is crucial for determining the indoor temperature of a building. Moreover, the green roof consumed a considerable fraction of net radiation for the latent heat (70.7%), whereas the bare concrete roof used a larger fraction of net radiation for the sensible heat flux (45.3%) and ground heat flux (16.2%). the green roof consumed a considerable amount of net radiation for the latent heat flux, but little ground heat flux. By contrast, the bare concrete roof used a larger fraction of the net radiation for the ground heat flux and the sensible heat flux, which increased the temperature of both the indoor building and the air close to the surface. These results demonstrate that a green roof not only reduces indoor temperature fluctuation but also helps mitigate the heat island effect directly.