Augmented human thermal discomfort in urban centers of the Arabian Peninsula.

Anthropogenic climate change has amplified human thermal discomfort in urban environments. Despite the considerable risks posed to public health, there is a lack of comprehensive research, evaluating the spatiotemporal changes in human thermal discomfort and its characteristics in hot-hyper arid regions, such as the Arabian Peninsula (AP). The current study analyzes spatiotemporal changes in human thermal discomfort categories and their characteristics in AP, using the newly developed high-resolution gridded ERA5-HEAT (Human thErmAl comforT) dataset for the period 1979-2022. In addition, the study assesses the interplay between the Universal Thermal Climate Index (UTCI) and El Niño-Southern Oscillation (ENSO) indices for the study period. The results reveal a significant increase in human thermal discomfort and its characteristics, with higher spatial variability in the AP region. The major urban centers in the southwestern, central, and southeastern parts of AP have experienced significant increases in human thermal discomfort (0.4-0.8 °C), with higher frequency and intensity of thermal stress during the study period. The temporal distribution demonstrates a linear increase in UTCI indices and their frequencies and intensities, particularly from 1998 onward, signifying a transition towards a hotter climate characterized by frequent, intense, and prolonged heat stress conditions. Moreover, the UTCI and ENSO indices exhibit a dipole pattern of correlation with a positive (negative) pattern in the southwestern (eastern parts) of AP. The study's findings suggest that policymakers and urban planners need to prioritize public health and well-being in AP's urban areas, especially for vulnerable groups, by implementing climate change adaptation and mitigation strategies, and carefully designing future cities to mitigate the effects of heat stress.

Comprehensive Analysis of Geopolymer Materials: Properties, Environmental Impacts, and Applications.

The advancement of eco-friendly technology in the construction sector has been improving rapidly in the last few years. As a result, multiple building materials were developed, enhanced, and proposed as replacements for some traditional materials. One notable example presents geopolymer as a substitute for ordinary Portland concrete (OPC). The manufacturing process of (OPC) generates CO2 emissions and a high energy demand, both of which contribute to ozone depletion and global warming. The implementation of geopolymer concrete (GPC) technology in the construction sector provides a path to more sustainable growth and a cleaner environment. This is due to geopolymer concrete's ability to reduce environmental pollutants and reduce the construction industry's carbon footprint. This is achieved through its unique composition, which typically involves industrial byproducts like fly ash or slag. These materials, rich in silicon and aluminum, react with alkaline solutions to form a binding gel, bypassing the need for the high-energy clinker production required in OPC. The use of such byproducts not only reduces CO2 emissions but also contributes to waste minimization. Additionally, geopolymer offers extra advantages compared to OPC, including improved mechanical strength, enhanced durability, and good stability in acidic and alkaline settings. Such properties make GPC particularly suitable for a range of construction environments, from industrial applications to infrastructure projects exposed to harsh conditions. This paper comprehensively reviews the different characteristics of geopolymers, which include their composition, compressive strength, durability, and curing methods. Furthermore, the environmental impacts related to the manufacturing of geopolymer materials were evaluated through the life-cycle assessment method. The result demonstrated that geopolymer concrete maintains positive environmental impacts due to the fact that it produces fewer carbon dioxide CO2 emissions compared to OPC concrete during its manufacturing; however, geopolymer concrete had some minor negative environmental impacts, including abiotic depletion, human toxicity, freshwater ecotoxicity, terrestrial ecotoxicity, and acidification. These are important considerations for ongoing research aimed at further improving the sustainability of geopolymer concrete. Moreover, it was determined that silicate content, curing temperature, and the proportion of alkaline solution to binder are the major factors significantly influencing the compressive strength of geopolymer concrete. The advancement of geopolymer technology represents not just a stride toward more sustainable construction practices but also paves the way for innovative approaches in the field of building materials.

Exploring urban growth-climate change-flood risk nexus in fast growing cities.

This study looks at the nexus between urban growth, climate change, and flood risk in Doha, Qatar, a hot-spot, climate change region that has experienced unprecedented urban growth during the last four decades. To this end, this study overviews the main stages of Doha's urban growth and influencing climatic factors during this period. A physically-based hydrological model was then built to simulate surface runoff and quantify flood risk. Finally, the Pearson correlation was used to verify the potential nexus between flood risk, climate change, and urban growth. Surveying showed that, between 1984 and 2020, urban areas grew by 777%, and bare lands decreased by 54.7%. In addition, Doha witnessed various climatic changes with a notable increase in air temperature (+ 8.7%), a decrease in surface wind speed (- 19.5%), and a decrease in potential evapotranspiration losses (- 33.5%). Growth in urban areas and the perturbation of climatic parameters caused runoff to increase by 422%, suggesting that urban growth contributed more than climatic parameters. Pearson correlation coefficient between flood risk and urban growth was strong (0.83) and significant at p < 0.05. Flood risk has a strong significant positive (negative) correlation with air temperature (wind speed) and a moderate positive (negative) correlation with precipitation (potential evapotranspiration). These results pave the way to integrate flood risk reduction measures in local urban development and climate change adaptation plans.

Computational analysis of solar thermal system with Prandtl nanofluid.

The solar thermal system can address a large amount of heating and cooling load required by buildings and industry. To enhance the absorption efficiency in solar thermal systems, nanofluids are considered as promising heat transfer medium. The study presents a numerical study to investigate physical feature of the entropy production in hydro-magnetic reactive unsteady flow of Prandtl nanoliquid over an infinite plate. The heat expression is modeled subject to thermal radiation and magnetic field. Innovative characteristics slip mechanisms i.e., thermophoresis diffusion and Brownian motion are also accounted. Mathematical modeling of entropy production is described by employing thermodynamics law (second law). Furthermore chemical reactions takes place at surface of plate are implemented. Nonlinear system are converted to dimensionless form via suitable transformation. The resultant system is solved by numerical approach (finite difference method). Characteristics of thermal field, entropy rate, fluid flow and concentration are physical discussed through sundry parameters. The outcomes display that the maximum velocity field exists near the center of the surface, whereas the average time flow enhances the velocity distribution. An augmentation in thermal field is distinguished versus magnetic parameter, while reverse behavior holds for fluid flow. An increase in the thermal field with respect to the magnetic variable is noted, while the opposite effect is observed for the fluid flow. A larger approximation of radiation rises entropy rate and thermal field. Increasing the Brownian motion variable increases concentration, while reverse impact is observed for Schmidt number.

Assessing the impact of climate conditions on the distribution of mosquito species in Qatar.

Qatar is a peninsular country with predominantly hot and humid weather, with 88% of the total population being immigrants. As such, it leaves the country liable to the introduction and dissemination of vector-borne diseases, in part due to the presence of native arthropod vectors. Qatar's weather is expected to become warmer with the changing climatic conditions across the globe. Environmental factors such as humidity and temperature contribute to the breeding and distribution of different types of mosquito species in a given region. If proper and timely precautions are not taken, a high rate of particular mosquito species can result in the transmission of various vector-borne diseases. In this study, we analyzed the environmental impact on the probability of occurrence of different mosquito species collected from several different sites in Qatar. The Naive Bayes model was used to calculate the posterior probability for various mosquito species. Further, the resulting Naive Bayes predictions were used to define the favorable environmental circumstances for identified mosquito species. The findings of this study will help in the planning and implementation of an active surveillance system and preventive measures to curb the spread of mosquitoes in Qatar.

Life-Cycle Assessment of Polypropylene Production in the Gulf Cooperation Council (GCC) Region.

The environmental impacts of the polypropylene (PP) manufacturing process are not fully understood in the Gulf Cooperation Council (GCC) region. There is a growing interest in assessing the environmental impacts of this highly demanded product, especially for the petrochemical industry sector. This research examines the environmental impacts of the polypropylene manufacturing process using a life cycle assessment (LCA) approach. Gabi software is selected to carry out this research study and quantify the risks associated with manufacturing one ton of polypropylene, chosen as the functional unit for this LCA study. This work has the following merits: (i) an evaluation of environmental impacts specific to GCC region based on actual plant data; (ii) the results in this work can be used to evaluate LCA impacts of PP based products; and (iii) emphasizing the importance of waste management in reducing environmental impacts. This study shows that the polypropylene manufacturing process releases numerous pollutants into the environment, as the gross CO2 emissions for the manufacturing process of PP in the plant located in the GCC region were estimated to be 1.58 kg CO2 eq./kg-PP. The manufacturing process of propylene has extremely high impacts on global warming potential, fossil resource depletion (1.722 kg Oil eq./kg-PP), human toxicity (0.077 kg 1,4-DB eq./kg-PP), acidification (0.0049 kg SO2 eq./kg-PP), and petrochemical oxidant formation (0.0042 kg NMVOC/kg-PP). Additionally, based on the results of this present research, this study proposes possible improvements and alternative solutions such as applying advanced technologies, clean energy, and safe recycling processes in the GCC that are environmentally friendly.

Indoor Air Quality in Buildings: A Comprehensive Review on the Factors Influencing Air Pollution in Residential and Commercial Structure.

Worldwide people tend to spend approximately 90% of their time in different indoor environments. Along with the penetration of outside air pollutants, contaminants are produced in indoor environments due to different activities such as heating, cooling, cooking, and emissions from building products and the materials used. As people spend most of their lives in indoor environments, this has a significant influence on human health and productivity. Despite the two decades of indoor air quality (IAQ) research from different perspectives, there is still a lack of comprehensive evaluation of peer-reviewed IAQ studies that specifically covers the relationship between the internal characteristics of different types of building environments with IAQ to help understand the progress and limitations of IAQ research worldwide. Therefore, this review of scientific studies presents a broad spectrum of pollutants identified in both residential and commercial indoor environments, highlighting the trends and gaps in IAQ research. Moreover, analysis of literature data enabled us to assess the different IAQs in buildings located in different countries/regions, thus reflecting the current global scientific understanding of IAQ. This review has the potential to benefit building professionals by establishing indoor air regulations that account for all indoor contaminant sources to create healthy and sustainable building environments.

Sustainability Assessment and Techno-Economic Analysis of Thermally Enhanced Polymer Tube for Multi-Effect Distillation (MED) Technology.

Metal-alloys tubes are used in the falling-film evaporator of the multi-effect distillation (MED) that is the dominant and efficient thermal seawater desalination process. However, the harsh seawater environment (high salinity and high temperature) causes scale precipitation and corrosion of MED evaporators' metal tubes, presenting a serious technical challenge to the process. Therefore, the metal/metal alloys used as the material of the MED evaporators' tubes are expensive and require high energy and costly tube fabrication process. On the other hand, polymers are low-cost, easy to fabricate into tubes, and highly corrosion-resistant, but have low thermal conductivity. Nevertheless, thermally conductive fillers can enhance the thermal conductivity of polymers. In this article, we carried out a feasibility-study-based techno-economic and socioeconomic analysis, as well as a life-cycle assessment (LCA), of a conventional MED desalination plant that uses titanium tubes and a plant that used thermally enhanced polymer composites (i.e., polyethylene (PE)-expanded graphite (EG) composite) as the tubes' material. Two different polymer composites containing 30% and 40% filler (expanded graphite/graphene) are considered. Our results indicate that the MED plant based on polymer composite tubes has favored economic and carbon emission metrics with the potential to reduce the cost of the MED evaporator (shell and tubes) by 40% below the cost of the titanium evaporator. Moreover, the equivalent carbon emissions associated with the composite polymer tubes' evaporator is 35% lower than titanium tubes. On the other hand, the ozone depletion, acidification, and fossil fuel depletion for the polymer composite tubes are comparable with that of the titanium tubes. The recycling of thermally enhanced polymers is not considered in this LCA analysis; however, after the end of life, reusing the polymer material into other products would lower the overall environmental impacts. Moreover, the polymer composite tubes can be produced locally, which will not only reduce the environmental impacts due to transportation but also create jobs for local manufacturing.

Properties and Microstructure Distribution of High-Performance Thermal Insulation Concrete.

The aim of this experimental study is to develop high strength and lightweight concrete mixture suitable for structural applications. This work investigates the effect of replacing normal aggregate either partially or totally with expanded perlite aggregate. This material allows for better thermal insulation properties, thus decreasing the energy usage within the life cycle of the concrete structure. Expanded perlite aggregate was used in concrete by 20%, 40%, 60%, 80%, and 100% in replacement of the natural aggregate. Material characterization tests of compressive strength, flexural strength, and thermal conductivity were carried out for six concrete mixtures. In addition, microstructure analysis was performed with the aid of a micro-computed tomography system to investigate the effects and relation of microstructure quantities on material properties. The proposed concrete mixture, which has 100% of expanded perlite aggregate, has a unit weight of 1703 kg/m3 and achieved reduction percentage of thermal conductivity around 62% (1.81 to 0.69 W·m-1·K-1) and a compressive strength of 42 MPa at 28 days; and thus is ideal for structural applications with enhanced properties.

Environmental impact of water-use in buildings: Latest developments from a life-cycle assessment perspective.

Globally, buildings are recognized as one of the highest users of freshwater resources. Consuming enormous amounts of constructional and operational water deplete water resources and ultimately generates a high environmental impact. This is mainly due to the energy required for the water cycle of built environments, which involves raw water treatment and distribution, use within buildings, and wastewater treatment. Moreover, the impact of water use varies significantly among countries/regions, due to different water use cycles. For example, many countries use conventional water treatments, while others rely on advanced desalination. Unlike building energy use, the impact of water use in buildings has not been captured fully in research. Given the significant impact of water use in buildings and global environmental degradation, we aimed to review studies concentrating on constructional and operational water use and associated environmental impacts, as well as studies that employed life cycle assessment (LCA) on this topic. The review indicated that a limited number of studies have focused on this serious issue in recent years, and their aims differed greatly. Therefore, there is a notable research gap in comprehensive environmental impact assessment including the total human water use cycle. Complete environmental assessment through LCA enables building professionals to understand the wide-ranging impact of water use in a building's life cycle from the environmental perspective in a given region. Additionally, this approach can benefit policymakers setting guidelines for new sustainable water strategies aimed at reducing environmental impacts.

Environmental performance of building integrated grey water reuse systems based on Life-Cycle Assessment: A systematic and bibliographic analysis.

The increasing demand for fresh water has been a global concern for decades. Desalination and water transportation systems consume an ample amount of energy, which also adds to the environmental pollution. This has led to a constant look-out for more viable options to conserve freshwater resources without compromising the environmental quality. The building sectors are remarkably the largest consumers of fresh water in the world; thus, the reclamation and reuse of greywater for non-potable purposes helps to reduce a significant amount of water consumed within a building. This study critically reviews the environmental performance of building-integrated greywater treatment systems compared to the conventional treatment systems deployed. Life-Cycle Assessment (LCA) is the method used to identify the environmental impacts associated with both the systems during their entire life span. The greywater treatment techniques and the guidelines for its reuse are also investigated. The bibliographic analysis was systematic, and the resources for this study were chosen after three stages of quality assessment. The study found physical and biological treatment techniques to be beneficial as they produce excellent quality of treated greywater for reuse. The environmental assessment by various studies prefers the reuse of greywater over its disposal. Guidelines for the reuse of treated greywater have recently been proposed by various countries and building rating systems. This study aims to address the policymakers, governmental and environmental organizations, mainly situated in the water-stressed areas such as the Middle East and North Africa (MENA) region, to raise awareness and initiate greywater reuse techniques within residential and commercial building sectors.

Performance evaluation of various individual and mixed media for greywater treatment in vertical nature-based systems.

Nature-based systems (NBS) are a cost-effective, energy efficient and aesthetically pleasing approach for greywater treatment, but they are space intensive. Vertical NBS overcome this issue but must utilize lightweight media to reduce their construction costs. This study evaluates four common plant growing media: perlite, coco coir, LECA and sand, and compares them with two new media derived from local waste materials: date seeds and spent coffee grounds (SCG). The media are characterized and tested for their removal of various greywater pollutants. Further tests are conducted comparing mixtures of perlite-coco coir and date seeds-SCG. SCG was found to be an excellent media for greywater treatment, providing a similar degree of treatment as the best traditional media, coco coir and providing improved drainage. Drainage was further improved by mixing SCG with date seeds, which performed better than any mixture of perlite and coco coir. Most pollutants showed a slight deterioration in treatment performance with this mixture, although the removal of suspended solids and chemical oxygen demand was improved. An increased bed height improved the treatment performance with SCG, while increased hydraulic loading resulted in decreased treatment performance for all media. This study demonstrates the potential of date seeds and SCG as locally recycled waste materials to realize treatment of greywater in vertical NBS.

Monitoring Electromagnetic Radiation Emissions in Buildings and Developing Strategies for Improved Indoor Environmental Quality.

Electronic devices have become ubiquitous in daily life, but they emit electromagnetic radiation, which may have negative health impacts at excessive levels. Little is known regarding the impact of radiation emissions on building occupants or strategies for reducing its intensity. This study applied a novel approach using system analysis to quantify radiation exposure in building spaces, examine building material responses to radiation propagation, and investigate risks to human health in the country of Qatar. Radiation intensity levels varied based on the location and type of building space. Different types of construction materials showed varied responses to electromagnetic field wave propagation. Drywall exhibited the best blocking effect, whereas glass and lumber walls exhibited poor blocking effects. The field strengths quantified in this study are less than the corresponding reference values specified by some jurisdictions, but they are still significantly higher than the safety levels defined in many other countries, which could result in significant health risks. The key strategies for improving indoor environmental quality include the use of shielding materials, spatial design, reduction of exposure time, increased exposure distance, and complete avoidance of exposure in sensitive areas.

Greywater recycling in buildings using living walls and green roofs: A review of the applicability and challenges.

Living walls and green roofs offer numerous benefits to densely populated urban areas such as cooling, air filtering and improved aesthetics. However, plants in these two systems are high water consumers making such systems particularly unsuitable for water-scarce arid environments most at need of passive cooling and urban greening. Integrated greywater treatment in these structures provides a possible solution, providing plants not only with water but other required nutrients and organics. However, greywater treatment by living wall and green roof systems is still lacking. This review summarizes the few studies exploring this new integrated technology and provides an in-depth analysis of existing literature on vegetated building structures and greywater treatment to reveal benefits and potential pitfalls of this technology. Appropriate selection of plants and media are essential to successful system design and must meet competing demands compared to those used in existing vegetated building structures for cooling/greening and constructed wetlands for greywater treatment. A variety of operational and user-interaction issues are also explored and will be key areas of future research to enable full-scale implementation. Integrated greywater treatment using green building vegetated structures appears a promising method for dual purpose water recycling and urban cooling, and various future research needs are emphasized to realize this.

Reducing electric energy consumption in linear Fresnel collector solar fields coupled to thermal desalination plants by optimal mirror defocusing.

In many parts of the world, desalination is the only viable and economic solution to the problem of fresh water shortage. The current commercial desalination technologies rely on fossil fuels and are thus associated with high greenhouse gas emissions that are a major cause of climatic changes. Solar thermal-driven multi-effect distillation with thermal vapor compression is a clean alternative to conventional desalination technologies. To comprehend this process, as well as its features and limitations, extensive modeling is required. In this work, we proposed a plant design based on a solar field with a linear Fresnel collector that supplies heat to a multi-effect distillation plant with thermal vapor compression. The solar desalination plant model is implemented in the Engineering Equation Solver (EES). The system performance is investigated and a control strategy for reducing electric pumping is proposed. Results showed that 1 m2 of the solar field produces 8.5 m3 of distillate per year. The proposed control strategy resulted in a 40% reduction in electric pumping energy. Our results highlight the versatility of the linear Fresnel collector when coupled with thermal desalination.

On-Site Renewable Energy and Green Buildings: A System-Level Analysis.

Adopting a green building rating system (GBRSs) that strongly considers use of renewable energy can have important environmental consequences, particularly in developing countries. In this paper, we studied on-site renewable energy and GBRSs at the system level to explore potential benefits and challenges. While we have focused on GBRSs, the findings can offer additional insight for renewable incentives across sectors. An energy model was built for 25 sites to compute the potential solar and wind power production on-site and available within the building footprint and regional climate. A life-cycle approach and cost analysis were then completed to analyze the environmental and economic impacts. Environmental impacts of renewable energy varied dramatically between sites, in some cases, the environmental benefits were limited despite the significant economic burden of those renewable systems on-site and vice versa. Our recommendation for GBRSs, and broader policies and regulations, is to require buildings with higher environmental impacts to achieve higher levels of energy performance and on-site renewable energy utilization, instead of fixed percentages.

Life-cycle thinking and the LEED rating system: global perspective on building energy use and environmental impacts.

This research investigates the relationship between energy use, geographic location, life cycle environmental impacts, and Leadership in Energy and Environmental Design (LEED). The researchers studied worldwide variations in building energy use and associated life cycle impacts in relation to the LEED rating systems. A Building Information Modeling (BIM) of a reference 43,000 ft(2) office building was developed and situated in 400 locations worldwide while making relevant changes to the energy model to meet reference codes, such as ASHRAE 90.1. Then life cycle environmental and human health impacts from the buildings' energy consumption were calculated. The results revealed considerable variations between sites in the U.S. and international locations (ranging from 394 ton CO2 equiv to 911 ton CO2 equiv, respectively). The variations indicate that location specific results, when paired with life cycle assessment, can be an effective means to achieve a better understanding of possible adverse environmental impacts as a result of building energy consumption in the context of green building rating systems. Looking at these factors in combination and using a systems approach may allow rating systems like LEED to continue to drive market transformation toward sustainable development, while taking into consideration both energy sources and building efficiency.