Roofing Sheets Research Articles

Introduction of RISCC model for a sustainable business risk management and control

This article evaluates traditional strategic management frameworks, such as SWOT, Porter’s Five Forces, and Blue Ocean Strategy, for their limitations in addressing regulatory compliance and environmental sustainability. While these models offer insights, they often lack a holistic, actionable strategy. The RISCC Model (Regulations, Internal Capability, Supplier, Customer, and Competitor) is introduced to fill these gaps by integrating regulatory requirements and sustainability considerations into strategic management. A case study of the asbestos fiber cement roofing sheets industry illustrates how this model enhances organizational resilience and competitive advantage by emphasizing compliance and sustainability in a rapidly evolving market.

Optimizing roofing efficiency: utilizing GGBS and coir fibre in cement tile production

Abstract The roof of a dwelling is the most significant and expensive. Low-cost heavy roofing construction frequently resulted in higher costs. The potential usage for coir, an eco-friendly building material, is as a raw material for corrugated roofing sheets and tiles. This study deals with the effects of using Ground Granulated Blast Furnace Slag (GGBS) as a partial replacement in cement roof tile production. The work is based on an experimental study of roofing tiles produced with Ordinary Portland Cement (OPC) and 10%, 20%, 30%, 40%, and 50% (OPC) replaced by GGBS (Ground Granulated Blast furnace slag). The optimum combination of fibre of 0.8% and replacement of GGBS of 40% in tiles was found optimum.

Hygrothermal Effect on Glass Fiber Reinforced Plastic (GFRP) Under Seawater Immersion

Glass Fiber Reinforced Plastic (GFRP) is extensively used for corrugated roofing sheets and gutters in Indonesia, especially in corrosive environments, due to its superior corrosion resistancecompared to steel. Despite its widespread application in coastal areas, limited studies have examined the durability of GFRP when exposed to seawater and heat. This research investigates the influence of hygrothermal conditions on the physical and mechanical properties of GFRP. Samples were immersed in seawater at temperatures of 30°C, 40°C, and 60°C for 3 and 6 months. Results show that hygrothermal exposure leads to degradation in physical but notmechanical properties. Physical properties were evaluated using mass gain measurements, hardness testing, and Scanning Electron Microscopy (SEM), while mechanical properties were assessed via tensile testing.The result shown all specimen have increased mass up to 3,8% and decrease in hardnessup to 56%. SEM also shown several dark spot which indicatevoid. SEM analysis revealed the presence of dark spots, indicating void formation. These findings underscore the vulnerability of GFRP to hygrothermal conditions, raising concerns about its long-term durability in coastal applications.

The Inflation Rate and the Prices of Roofing Sheets in Benin City

This research aimed to examine the correlation between the inflation rate and the cost of roofing sheets in Benin City to help minimize the negative impact of inflation on the construction sector. The study analyzed the inflation rate and the prices of selected roofing sheets from 2017 to 2022, and the link between the inflation rate and the prices of these roofing sheets was determined using Spearman’s correlation coefficient and Regression analysis. Inflation rate data was sourced from the Central Bank of Nigeria, while the prices of the selected roofing sheets were gathered through a market survey. The study found that the inflation rate reached its peak in 2022. Additionally, the prices of the selected building materials showed an increasing trend from 2017 to 2022. Through the percentage deviation of the variables, it was established that a 1% rise in the inflation rate would result in a 5.27% increase in the price of Corrugated Zinc roofing sheet, a 6.79% increase in the price of Corrugated Zinc roofing sheet from Ghana, a 1.40% increase in the price of Shortspan Aluminium roofing sheet, a 3.16% increase in the price of Coloured longspan roofing sheet, a 4.93% increase in the price of Stucco longspan roofing sheet, and a 2.24% increase in the price of Stone coated roofing sheet. Correlation analysis confirmed the existence of a relationship between inflation and the prices of roofing sheets. Furthermore, Regression analysis indicated that the prices of Corrugated Zinc roofing sheets, Corrugated Zinc roofing sheets from Ghana, Shortspan Aluminium roofing sheets, Coloured Longspan Aluminium roofing sheets, Stucco Longspan Aluminium roofing sheets, and Stone Coated roofing sheets would increase by ₦65.73k, ₦57.89k, ₦63.97k, ₦193.2k, ₦286.6k, ₦62 respectively for every unit increase in the inflation rate. It was recommended that the Government should provide subsidies and tax incentives that will promote the local production of roofing sheets to reduce dependency on imports and effects from inflation fluctuations.

Effect of Various Roofing Materials on Physiological Response of Osmanabadi Kids

The present study was carried out at Osmanabadi goat unit of Red Kandhari Research and Instructional Farm, College of Veterinary and Animal Sciences, Parbhani, MAFSU, for a period of 90 days. Eighteen Osmanabadi kids were divided into three treatment groups viz T0 (Thatch roof) T1 (Asbestos roof) T2 (FRP sheet roof). The variation in weekly pulse rate, respiration rate and body temperature were recorded in the morning and evening throughout the experiment. The results revealed that the thatch roof shed significantly (P<0.05) reduced pulse rate, respiration rate and body temperature of kids. The study concluded that thatch roof effectively improves environmental temperature and humidity than asbestos roof and FRP sheet roof shed.

Evaluation of the Impact of Temperature on the Performance of Photovoltaic Solar Panels Installed on Various Roofing Sheets

The performance and efficiency of Photovoltaic (PV) Modules are usually rated under standard test conditions (STC). However, PV modules operate over a wide range of environmental conditions at the field, which are further affected by the method of installation, especially when it comes to roof-mount systems, as different roofing materials are used for roofing houses and solar modules are mounted on them directly. In this study the effect of temperature on the output performance of photovoltaic modules mounted on four different roofing materials (stone coated, long span aluminum, corrugated zinc and short span aluminum) is investigated. Solar panels are separately installed directly on, and then elevated over, different types of roofing sheets. Results show that module installed directly on stone coated roofing material had an overall output performance of 89.52% followed by short span, long span aluminum, and corrugated zinc roofing materials with performances of 89.40%, 89.32%, and 85.54%, respectively. For the elevated set up, the same modules showed improved output performances of 96.16%, 90.30%, 89.30% and 87.84% for stone coated, long span, short span aluminum and corrugated zinc, respectively. The best output performance by the elevated stone coated roof type may be attributed to the fact that the roofing material absorbs nearly all the solar radiation thereby reflecting very little radiation back on the module. The converse is also true for the corrugated zinc material, which had the least output performance. Modules mounted directly on the roof show a strong correlation between the roof and module temperatures with the corrugated zinc roofing sheet showing the strongest correlation with a coefficient of 0.980 while for modules elevated above the rooftop the stone coated roofing sheet showed the strongest correlation with a coefficient of 0.888. For optimum performance, it is recommended that panels mounted on rooftops be elevated above the roof.

Solar Disinfection of Drinking Water in Semi-Temperate Rural Community of Jos, Nigeria

A significant number of the world’s population lacks access to safe drinking water, relying mostly on wells and streams, which are usually contaminated with faeces and other pollutants, as sources of drinking water. This results in many diseases that plague these communities, predominantly in rural areas of developing countries where there is abundant solar radiation all year round. SODIS is a popular method of disinfecting water with remarkable success in many rural areas globally. This method was used in Maza community of Jos North Local Government area of Plateau state in the current study. 2-liter PET bottles, differently modified, were filled with water and placed on corrugated roofing sheets for direct exposure to solar radiation. Some of the bottles were modified by painting them white, white with insulation, half black, black with insulation, and plain with insulation. Delagoa test kits applied to contaminated SODIS bottle showed rapid decrease in the concentration of pathogen at about 40 0C. The Black painted Insulated modified bottle presented the highest maximum temperature of 62.0 0C, which occurred around 2 pm, while the least maximum temperature (53.0 0C) was obtained at the same time for the white modified bottle. Though the plain unmodified bottle showed the least temperature the value was higher than the ambient temperature of Maza. Contrasting the maximum SODIS temperature of the black modified bottle to the corresponding maximum value for the ambient temperature indicates a 29 0C (96.7 %) rise in temperature within 6 hours. SODIS modification, therefore, enhances the temperature of water by several degrees, and can, therefore, be deployed as an alternative means for households in Maza community to access safe drinking water.

Impact of air quality on the health of present-day workers in an Asbestos roof manufacturing industry, Sri Lanka.

The study's objective was to determine the air quality in an asbestos-related industry and its impact on current workers' respiratory health. Seventy-seven air and 65 dust samples were collected at 5-day intervals in an asbestos roofing sheets production factory in Sri Lanka having two production facilities. Sampling was performed in ten sites: Defective sheets-storage, Production-plant, Pulverizer, Cement-silo, and Loading-area. A detailed questionnaire and medical screening were conducted on 264 workers, including Lung Function Tests (LFT) and chest X-rays. Asbestos fibres were observed in deposited dust samples collected from seven sites. Free chrysotile fibres were absent in the breathing air samples. Scanning Electron Microscopy confirmed the presence of asbestos fibres, and the Energy Dispersive X-ray analysis revealed Mg, O, and Si in depositions. The average concentrations of trace metals were Cd-2.74, Pb-17.18, Ni-46.68, Cr-81.01, As-7.12, Co-6.77, and Cu-43.04mg/kg. The average Zn, Al, Mg, and Fe concentrations were within 0.2-163g/kg. The highest concentrations of PM2.52.5 and PM1010, 258 and 387µg/m3, respectively, were observed in the Pulverizer site. Forty-four workers had respiratory symptoms, 64 presented LFT abnormalities, 5 indicated chest irregularities, 35.98% were smokers, and 37.5% of workers with abnormal LFT results were smokers. The correlation coefficients between LFT results and work duration with respiratory symptoms and work duration and chest X-ray results were 0.022 and 0.011, respectively. In conclusion, most pulmonary disorders observed cannot directly correlate to Asbestos exposure due to negligible fibres in breathing air, but fibres in the depositions and dust can influence the pulmonary health of the employees.

Atmospheric Corrosion of Al-Zn Coated Steel Sheets Exposed under Marine Environments in Kenya

Corrosion contributes to multibillion USA dollar loses due to deterioration, weakening and ultimate failure of engineering infrastructure globally necessitating further research to build more corrosion resistant materials. The aim of this study was to investigate atmospheric corrosion of aluminium-zinc coated steel roofing sheets exposed to outdoor marine environment in Kenya at Diani and Mariakani sites, representing severe marine and urban marine environments respectively. Al-Zn coated sheets measuring 130 mm x 190 mm coated with masses ranging from 60-150 gm2 were exposed for 2 years. The specimens were collected at periodic intervals following ASTM G1-90 standard method and corrosion products analyzed by Raman spectroscopy, while corrosion rate was determined by weight loss method. Corrosion rate ranged from 0.03 to 0.05 mmpy and increased with decreasing masses coating materials from 150 to 60 (gm2). Diani site recorded higher corrosion due to severe marine conditions characterized by high chlorides, RH of 81%, UV of 12mW/cm2 and a temperature of 27 ℃. Dominant rust constituents were goethite (a-FeOOH) and lepidocrocite (g-FeOOH), while ferrihydrite and maghemite (a-Fe2O3) were measured at low levels suggesting the influence of suphur dioxide and chloride pollution on corrosion rate at both sites. Corossion rates ˂ 0.15 mmpy at both sites suggest excellent protection by the formulated coating media. The results of this contribute to improving the quality of the AZ metal coating media under marine environments.

Roosting and nesting ecology of house sparrow (\(\textit{Passer domesticus}\)) in Guwahati city, Assam

Aves are unique in having a coat of feathers and in balancing on the hind limbs alone. They are known as the feathered bipeds. Roosting, nest building in birds has been considered a remarkable behaviour in aves. The nesting ecology of birds is likely the most important component of its life history and it is affected by several ecological and environmental factors. Guwahati city, a rapidly growing city in northeast India inhabits a lot of species of birds. It is located between the Brahmaputra River’s southern bank and the Shillong plateau’s foothills. Total of the 57 nests, 28% were discovered in the rolling shop shutters, followed by 27% in the tin sheet roofs of homes, followed by 19% in building crevices, 9% in building holes, 7% in advertisement hoarding and 5% in AC outdoor units and 5% in unused building pipes. It is also observed that 49% of the nests are located at a height between 2–4 metres from the ground level, 70% of the nests are located between 1–5 metres from the nearest food source, and 58% of the nests are located between 1–5 metres from the nearest water source. Out of the 57 nests observed, 50 were found to be solitary, 5 were found to be Pair, and 2 were found to be cluster type. The study found that choosing a nest is influenced directly by the location of the nearest food source and nearest water source in Guwahati city. The study presents the merit and needs for studying the nesting ecology of birds in India, also suggests best practices to conserve bird’s nest specific to the Indian context which might provide important information for the nesting ecology of House Sparrows (Passer domesticus).

Characterization of Village Chicken Production Systems in Three Agro-climatic Zones of Western Tigray, Northern, Ethiopia

A survey was conducted in Tigray, Northern Ethiopia, to characterize village chicken production systems using a questionnaire and group discussions. Data was analyzed using SPSS 22. Respondents provided supplementary feeds to chickens to improve yields and health. Sorghum, maize, sesame, tomato, onion, barley, and household food leftovers were the main supplementary feeds, although the types of cereal crops produced varied across agro-climates. Harvest and purchase were main sources of cereal and non-cereal chicken feeds, respectively. 50.4% considered summer, 48.8% winter as critical feed seasons. Farmers provided feeds to their chickens in the morning (98.7%), afternoon (69.6%), and evening (81.3%), and on the ground for collective feeding (97.9%). 59.5% of respondents constructed separate chicken houses, with 56.1% being permanent structures and 3.4% temporary. Chicken houses were constructed using materials such as mud, wood, iron sheet roofing, bamboo, grass, and plastic. 57.7% cleaned chicken houses, 66% once daily, and 2.1% not at all. Water was provided ad libitum (70.9%), once a day (7.5%), or twice a day (21.6%) from wells, taps, or rivers using various waterers. Eighty-six percent of the respondents cleaned chicken waterers, while the remaining 14% did not. Training is needed for house construction, feeding, watering, cleaning, and disinfection of feeders and waterers to prevent waterborne diseases.

Effect of Different Storage Vessels on the Microbiological and Physicochemical Properties of Rainwater Harvested from Different Rooftops in Owerri, Nigeria

This study evaluated the effect of different storage vessels on the microbiological and physicochemical properties of rainwater harvested from different rooftops in Owerri. Different storage vessels were assembled and used to stored rainwater delivered by using different catchments. The catchments used were corrugated iron sheet roof, asbestos roof, stone coated roof, aluminum roof, and thatched roof. Rainwater was also collected directly from rainfall, in the open environment and stored in the vessels. The storage vessels were plastic contain, metal tank, earthen ware pot, and block/cemented tank. The study was designed in such a way that each of the storage vessels received water from each of the catchments for storage. In all, a total of 24 storage vessels were used. Each of the catchment delivered rainwater to a peculiar plastic container, metal samples were allowed to stay in the vessels for some days before they were taken to the laboratory for analysis using standard methods. From the results observed, the storage vessels made more microbial impact on the stored rainwater samples that physicochemical impact. Six bacterial and mould organisms were isolated from the stored rainwater samples. However, the molecular identification study for the bacterial organisms revealed plasmid possessed E. coli, P. aeruginosa, and Enterobacter sp., which made them resistant to the antibacterial drugs. From the observation of the present study, storage vessels may impact more on bacterial contamination than physicochemical or metal contamination. This study has shown the effect of different storage vessels on the microbiological and physicochemical properties of rainwater harvested from different rooftops in Owerri, Nigeria.

Minimization of Root Causes of Declining Productivity in a Manufacturing Company: A Case Study of Jocalis Company

This presents a comprehensive methodology employed to identify and address declining productivity issues within the JOCALIS Aluminium Roofing Sheet Manufacturing Company Limited, situated in Onitsha, Nigeria. The study encompasses various manufacturing divisions, with a primary focus on aluminium roofing sheet production of three lines involve in production of red, black, and milk colour coated roofing sheet. The research aims to uncover the root causes of defects in the manufacturing process and develop effective strategies for improvement. Key methods include data collection through interviews, company records, library research, and internet sources, followed by data analysis and root cause identification. From the result obtained, the average availability of critical machine like the roller machine after root cause analysis is increased by 10.62%. Also, the average MTBF (mean time between failure) of the critical machine after root cause analysis is increased by 13.66% and MTTR (mean time to repair) is decreased to 46.42% respectively. The applications and general impact of this study includes enhancing machine availability, reducing downtime, increasing efficiency, optimizing maintenance practices, implementing preventive maintenance schedules, improving equipment diagnostics, and prioritizing root cause analysis to reduce breakdowns.

Analysis Based on Ecotect Software of the Energy Consumption and Economic Viability of Solar Collector Pig Houses with Different Roof Forms and Translucent Materials

This study investigated improvements in solar energy efficiency in pig houses with different roof types and translucent materials using Ecotect simulation software v2011. An experimental pig house in Qian Guo County, Songyuan City, was selected as the research object. First, the optimal building orientation for pig houses was explored by analysing the solar irradiance received as a primary indicator. Next, the energy consumption of pig houses was simulated using various translucent materials in the roof. Various roof types were designed based on the optimal translucent material. The energy consumption of these designs was compared with that of the experimental pig house. Finally, the economic viability of the different pig houses was analysed. The results showed that the optimal building orientation for a pig house was south by west 25°. Among the pig houses with equal-slope roofs using FRP daylighting boards, double-layer polycarbonate (PC) sheets, flat glass, and organic glass as translucent materials, the pig house using double-layer PC sheets required the least amount of additional heat during the heating season (62,109 kWh). For pig houses with double-layer PC sheets, four roof designs were assessed (equal-slope roof, front and rear roofs with unequal slopes, upper and lower staggered unequal-slope roof, and four-equal-slope roof), and it was found that the pig house with a four-equal-slope roof required the least amount of additional heat during the heating season (48,138 kWh). The economic analysis indicates that the combination of a four-equal-slope roof and double-layer PC sheets is the most cost-effective option, with the lowest total life cycle cost. This design saves 9521 USD compared with the experimental pig housing, effectively improving solar energy utilisation efficiency. These analyses provide a reference for exploring the thermal performance of pig houses.

Laboratory tests to understand tephra sliding behaviour on roofs

Following explosive eruptions, loading from tephra fall deposits can lead to roof collapse. However, the load may be reduced significantly by tephra sliding on pitched roofs. We present small-scale laboratory tests to investigate tephra sliding behaviour on metal, fibre cement sheet and tile roofing. We tested 10–30 cm thicknesses for dry and wet deposits of pumice, scoria and basaltic ash. We found that tephra did not slide on roof pitches ≤ 15° for coarse-grained deposits and ≤ 12° for dry ash. Thin deposits of wet ash were stable at pitches ≤ 30°. In addition, tephra was mainly shed on pitches ≥ 32° for metal roofs and ≥ 35° for fibre cement and tiles. Using these results, we have produced an initial set of sliding coefficients for tephra for simply pitched roofs that can be used to help prioritise roofs for clearing during an eruption and assist in designing roofs to withstand tephra fall.

The Impact of Roof Material Profile and Pigmentation on the Performance of Photovoltaic Modules

This study combines simulations and experiments to study the heat interactions between various types of roofs and the photovoltaic (PV) modules installed on them. Specifically, the performance of PV modules on a clay roof was compared with their performance on two types of metal roofs, a Box-profile metal roof and an Orientile metal roof, which differ in shape and geometry. Additionally, this study examined the cooling potential of three common metal roof pigments, iron (iii) oxide (Fe2O3), titanium dioxide (TiO2) and basalt, on roof-installed PV modules. An unpigmented roof was also studied for comparison purposes. Model development and simulation were implemented in COMSOL Multiphysics, and the simulation results were validated and compared with field experiments. The maximum open-circuit voltages of the PV installations were found to be 21.096 V for the clay roof, 20.945 V for the Box-profile metal roof and 20.718 V for the Orientile metal roof. This study revealed that the unpigmented roof had higher solar cell temperatures compared to the pigmented models, with temperature gains ranging from 2.2 °C to 2.71 °C. Moreover, the unpigmented model displayed significantly higher surface radiosity than the pigmented models. The performance output of the modules also varied depending on the metal roof sheet shape and geometry, with the Box-profile metal roof yielding better results than the Orientile metal roof sheet. These results indicate that a specific roof pigmentation may have a small impact on a single PV module, but it can become significant in a large array of modules, especially if cooling through natural convection is hindered.

Kitchen fine particulate matter (PM2.5) concentrations from biomass fuel use in rural households of Northwest Ethiopia.

Combustion of solid biomass fuels using traditional stoves which is the daily routine for 3 billion people emits various air pollutants including fine particulate matter which is one of the widely recognized risk factors for various cardiorespiratory and other health problems. But, there is only limited evidences of kitchen PM2.5 concentrations in rural Ethiopia. This study is aimed to estimate the 24-h average kitchen area concentrations of PM2.5 and to identify associated factors in rural households of northwest Ethiopia. The average kitchen area PM2.5 concentrations were measured using a low-cost light-scattering Particle and Temperature Sensor Plus (PATS+) for a 24-h sampling period. Data from the PATS+ was downloaded in electronic form for further analysis. Other characteristics were collected using face-to-face interviews. Independent sample t-test and one-way analysis of variance were used to test differences in PM2.5 concentrations between and among various characteristics, respectively. Mixed fuels were the most common cooking biomass fuel. The 24-h average kitchen PM2.5 concentrations was estimated to be 405 μg/m3, ranging from 52 to 965 μg/m3. The average concentrations were 639 vs. 336 μg/m3 (p < 0.001) in the thatched and corrugated iron sheet roof kitchens, respectively. The average concentration was also higher among mixed fuel users at 493 vs. 347 μg/m3 (p = 0.042) compared with firewood users and 493 vs. 233 μg/m3 (p = 0.007) as compared with crop residue fuel users. Statistically significant differences were also observed across starter fuel types 613 vs. 343 μg/m3 (p = 0.016) for kerosene vs. dried leaves and Injera baking events 523 vs. 343 μg/m3 (p < 0.001) for baked vs. not baked events. The average kitchen PM2.5 concentrations in the study area exceeded the world health organization indoor air quality guideline value of 15 μg/m3 which can put pregnant women at greater risk and contribute to poor pregnancy outcomes. Thatched roof kitchen, mixed cooking fuel, kerosene fire starter, and Injera baking events were positively associated with high-level average kitchen PM2.5. concentration. Simple cost-effective interventions like the use of chimney-fitted improved stoves and sensitizing women about factors that aggravate kitchen PM2.5 concentrations could reduce kitchen PM 2.5 levels in the future.

Optimization using Taguchi Method to Investigate the Effects of Process Parameters on the Hardness of Developed Aluminium Roofing Sheets

This study focused on the optimization using taguchi method to ınvestigate the effects of process parameters on the hardness of developed aluminium roofing sheets. Maximizing process variables like manufacturing temperature, manufacturing pressure, cooling time, and percentage of magnesium in aluminium, the Taguchi Method, a statistical method, was used to enhance the manufacturing quality of aluminium roofing sheets. Using an orthogonal array, a signal-to-noise ratio, and an analysis of variance, the effects of process variables on the hardness of the produced aluminium roofing sheets were examined. In this analysis, four factors; manufacturing temperature, manufacturing pressure, cooling time, and the precentage of magnesium in the aluminium roofing sheet were investigated. Thus, a suitable orthogonal array was selected, and experiments were conducted. Following the trial, the process parameters were evaluated, and the signal-to-noise ratio was calculated. The best parameter values were determined with the use of graphs, and confirmation trials were performed. The results showed that an aluminium roofing sheet's maximum hardness of 65.0kgf was obtained at a manufacturing temperature of 1250 °C, a manufacturing pressure of 65 GPa, a cooling period of 95 seconds, and a magnesium content of 0.5%. The most important influences on the hardness of aluminium roofing sheets was found to be the precentage of magnesium in aluminium roofing sheets followed by manufacturing pressure and manufacturing temperature. The cooling time was found to be the least efficient one. The obtained results in this study were used to improve the material property (hardness) of aluminum roofing sheet and investigate the effects of production factors in aluminum production industries.

Experimental Investigation on Mechanical Characterization, Ranking and Water Absorption Behavior of RHA/WDA/RHAWDA Filled Epoxy Based Glass Fiber Reinforced Hybrid Composites

In the present research work, a novel class of epoxy built hybrid combinations strengthened with E-Glass woven rowed mat and occupied with rice husk ash (RHA), wood dust ash (WDA) and a mixture of RHA &amp; WDA has been developed and structural mechanical properties were determined and the results were matched with the non-filled composites. The studies on these composites reveal that the tensile strength (TS) of the composites is decreased by the escalation in weight percentage of the filler material and the rest of the mechanical properties were increased with the increase in weightiness proportion of RHA, WDA and RHAWDA. TOPSIS and VIKOR’S ranking methods are applied to know the best composite from 16 alternative composites having 6 attributes. From the results, the composite filled with RHA at 5 wt% is selected as the best composite based on mechanical characteristics. Water absorption behavior of the composites at various time intervals for RHA, WDA and RHAWDA filled hybrid composites has been studied and it is concluded that the composites occupied with RHA at 12.5 wt% have given the minimum water absorption rate (WA) compared to other filled composites immersed in distilled and mineral waters and the composite filled with WDA at 2.5 wt% has exhibited the minimum water absorption rate (WA) when it is immersed in ground water for 144 hours of a time interval. Based on the results of water absorption rate (WA) and mechanical characteristics (impact strength and Vickers hardness) the composites filled with RHA at 5 wt% and RHA at 12.5 wt% can be used for the manufacturing of roof sheets and water tanks.

Quantifying the benefits of PV module shading for building heat gain reduction: A machine learning approach

This study investigates the indirect benefit due to the shading effect from PV rooftop systems installed on building envelopes by proposing a new method based on a machine-learning algorithm. The study gathered a year of data from a 25 kWp PV rooftop system installed on a metal sheet roofing. It classifies the dataset into four categories based on solar irradiance and ambient temperature to represent Thailand's climate. There evaluated the RTTV and case study from implemented projects with metal sheet roofing in Thailand to estimate the potential electricity bill savings from the PV module shade effect. The results reveal an inverse relationship between the percentage of heat reduction and heat gain reduction, with the most significant reduction occurring under high solar irradiance and ambient temperature conditions. The shading effect caused by the PV modules provides an indirect benefit of approximately 38 kWh/kWp/year from electricity bill savings. In contrast, the PV system production yields around 1401 kWh/kWp/year based on radiation of about 1839 kWh/m2/year. The study estimates that energy-saving possibilities range from 0.038 to 0.052 kWh/m2/day, depending on the weather conditions, equivalent to an electricity saving of approximately 6.33 kWh/m2/year from air conditioner use.