Search Results (25)

Microplastic contamination in aquatic systems in urban areas is a cause for concern due to its ability to move from one location to another. This review investigates microplastic levels across different aquatic environments and its potential transport through the urban water cycle. This study explores current research on the presence and pathways of microplastics movement within the water cycle. It includes a comprehensive bibliometric analysis that identifies publication trends, dominant research themes, influential journals, and leading contributing countries. It covers microplastic occurrence across various natural environments, including marine, river, lake, and groundwater systems, and extends into the built environment such as water treatment facilities, wastewater systems, bottled water, and drinking water distribution networks. Results indicate that microplastic levels vary within the urban water cycle, with concentrations differing widely depending on geography, type of infrastructure, and sampling methodology. Despite some removal efficiency during treatment processes, residual microplastics remain prevalent in effluents and drinking water, posing potential ecological and health risks. This study identifies that some of the major challenges in determining the fate and transport of microplastics are inconsistent sampling methods, lack of standardization, and limited understanding of long-term impacts. This paper also identifies the necessity of coordinated global strategies that integrate policy, technology, and public awareness to mitigate microplastic contamination in urban water systems. Full article

According to Victor Ernest Shelford’s ‘Law of Tolerance,’ organisms within ecosystems thrive optimally when environmental conditions are favorable. Applying this principle to ecosystems and agro-ecosystems facing water scarcity or environmental challenges can significantly enhance their productivity. In these ecosystems, phytocenosis adjusts its conditions by utilizing water with varying salinity levels. Moreover, establishing optimal drinking water conditions for human populations within an ecosystem can help mitigate future negative succession processes. The purpose of this study is to evaluate the quality of two distinct water sources in the Amudarya district of the Republic of Karakalpakstan, Uzbekistan: collector-drainage water and groundwater at depths of 10 to 25 m. This research is highly relevant in the context of climate change, as improper management of water salinity, particularly in collector-drainage water, may exacerbate soil salinization and degrade drinking water quality. The primary methodology of this study is as follows: The Food and Agriculture Organization of the United Nations (FAO) standard for collector-drainage water is applied, and the water quality index is assessed using the CCME WQI model. The Canadian Council of Ministers of the Environment (CCME) model is adapted to assess groundwater quality using Uzbekistan’s national drinking water quality standards. The results of two years of collected data, i.e., 2021 and 2023, show that the water quality index of collector-drainage water indicates that it has limited potential for use as secondary water for the irrigation of sensitive crops and has been classified as ‘Poor’. As a result, salinity increased by 8.33% by 2023. In contrast, groundwater quality was rated as ‘Fair’ in 2021, showing a slight deterioration by 2023. Moreover, a comparative analysis of CCME WQI values for collector-drainage and groundwater in the region, in conjunction with findings from Ethiopia, India, Iraq, and Turkey, indicates a consistent decline in water quality, primarily due to agriculture and various other anthropogenic pollution sources, underscoring the critical need for sustainable water resource management. This study highlights the need to use organic fertilizers in agriculture to protect drinking water quality, improve crop yields, and promote soil health, while reducing reliance on chemical inputs. Furthermore, adopting WQI models under changing climatic conditions can improve agricultural productivity, enhance groundwater quality, and provide better environmental monitoring systems. Full article

The indoor environmental quality (IEQ) in buildings is vital for health, work efficiency, productivity, and the overall sustainability of buildings. IEQ is governed by four parameters: indoor air quality and thermal, acoustic, and visual comfort. The recent pandemic has compelled people to think beyond energy efficiency and refocus on the health, well-being, and productivity of building occupants. Despite numerous IEQ guidelines and standards, there remains a paucity of systematic research that critically examines the relationship between IEQ and building energy efficiency. This systematic review explores the existing equilibrium and identifies gaps between IEQ standards and building energy codes. Firstly, this review examined the status of the IEQ standards and identified that most of the North American IEQ guidelines cannot achieve energy efficiency targets. Secondly, existing building energy codes were reviewed to determine how well these codes fare with IEQ requirements. It was revealed that the expensive energy certification documents are more focused on IEQ than traditional energy codes. The identified factors indicate that most building energy codes can meet only indoor air quality thresholds (a subset of IEQ), while other parameters are inadequately addressed. This review revealed 19 relationships between IEQs and energy efficiency. Building energy code/IEQ guidelines developers could consider the identified 19 relationships to develop a combined set of guidelines/standards for future building stock. An integration model between IEQ and energy efficiency is proposed as a future research direction to contribute to the better design and construction of modern buildings. The findings will facilitate the construction of healthy and sustainable buildings, and they aim to generate new residential communities that achieve an optimal health–energy–carbon nexus. Full article

Metallic nanoparticles are very useful, effective, and usually synthesized by toxic and expensive chemicals. Silver nanoparticles (AgNPs), measuring less than 100 nm, have shown promising impact in several biomedical investigations. These can inhibit microbial growth and aid in medicine administration. Six substrates of Carica papaya were used to synthesize silver nanoparticles that can limit the growth of bacteria and fungi. In this article, we report the synthesis of AgNPs from the leaf, seed, callus, peel, fruit juice, and bark of Carica papaya. AgNPs synthesized from callus showed the most promising results when tested against the growth of bacteria like Xanthomonas campestris, Erwinia carotovera, Bacillus subtilis, and fungi (Aspergillus niger and Fusarium oxysporum) when compared with other extracts’ efficacy, and the callus was regenerated from petiole and midrib explants of Carica papaya in MS basal media supplemented with NAA and Kinetin (1 + 0.5 mg/L). A ratio of 1:20 of substrate extract to 1 mM AgNO₃ produced the most effective nanoparticles in terms of capping, quality, and stability when tested through surface plasmon resonance (SPR) within the 400–435 nm range. The nanoparticle sizes of all six types were measured using Image J software on micrographs of SEM at 200 nm resolution. The average diameters were analyzed through Origin software, and the finest AgNPs were observed to be synthesized from callus extract, i.e., 18.91 nm with rod-like morphology. Energy dispersive X-ray (EDX) at 2.6 keV revealed 43.38, 75.39, 70.611, 36.54, 58.57, and 45.94 percent elemental silver in AgNPs formed from the leaf, callus, juice, seed, bark, and peel extract, respectively. Silver nanoparticles synthesized from callus extract were smaller and exhibited the most effective antimicrobial potential, with the highest inhibitory zone of 19 mm against Xanthomonas campestris bacterium and up to 14 mm against Aspergillus niger fungus. Furthermore, the percentage of elemental Ag (measured through EDX) was found to be highest in the nanoparticles synthesized from callus compared to those synthesized from the leaf, seed, peel, fruit juice, and bark of Carica papaya. Hence, the callus extract is the most suitable substrate for the reduction of silver nitrate solution in 1:20 to form the finest silver nanoparticles in an effective biogenic way. Full article

Building energy retrofits can reduce emissions and increase cost savings. Some retrofits that can deliver higher emissions savings are not popular due to a lack of economic justifications. Financial incentives can be used to change buyer perception around such retrofits. This study proposes a framework to identify the best-performing retrofit strategies for a given building cluster and the optimal incentive amounts to promote the chosen strategies, accounting for uncertainties, stakeholder priorities, and budget constraints. The proposed framework was demonstrated using a case study complemented with policy insights. Life cycle cost savings and capital cost significantly impact retrofit purchase decisions. Case study results showed that retrofitting houses heated with electricity can produce significant cost savings. However, adopting energy-conscious behaviours in houses heated with natural gas and injecting renewable natural gas into the gas supply can produce two times more emissions savings achieved by any retrofit strategy applied to an electrically heated house. This indicates the need for adopting performance-based incentives over the prescriptive approach to reward occupant efforts in addition to asset performance. Despite potential life cycle cost savings, incentives must be complemented with low-interest loans to promote retrofit strategies carrying higher capital costs. Full article

Human papilloma virus (HPV) causes cervical and many other cancers. Recent trend in vaccine design is shifted toward epitope-based developments that are more specific, safe, and easy to produce. In this study, we predicted eight immunogenic peptides of CD4+ and CD8+ T-lymphocytes (MHC class I and II as M1 and M2) including early proteins (E2 and E6), major (L1) and minor capsid protein (L2). Male and female Sprague Dawly rats in groups were immunized with each synthetic peptide. L1M1, L1M2, L2M1, and L2M2 induced significant immunogenic response compared to E2M1, E2M2, E6M1 and E6M2. We observed optimal titer of IgG antibodies (>1.25 g/L), interferon-γ (>64 ng/L), and granzyme-B (>40 pg/mL) compared to control at second booster dose (240 µg/500 µL). The induction of peptide-specific IgG antibodies in immunized rats indicates the T-cell dependent B-lymphocyte activation. A substantial CD4+ and CD8+ cell count was observed at 240 µg/500 µL. In male and female rats, CD8+ cell count for L1 and L2 peptide is 3000 and 3118, and CD4+ is 3369 and 3484 respectively compared to control. In conclusion, we demonstrated that L1M1, L1M2, L2M1, L2M2 are likely to contain potential epitopes for induction of immune responses supporting the feasibility of peptide-based vaccine development for HPV. Full article

Historically, the combination of generous subsidies along with extreme climate has led to unsustainable domestic electricity consumption in Saudi Arabia. The residential sector constitutes a significant portion of this consumption. Amid the economic challenges, the country enforced a new electricity tariff for residential consumers in 2018. This study thus leverages change in 2018–2020 by collecting and analyzing the electricity consumption data of 73 households in the Eastern Province of Saudi Arabia. The energy consumption is modeled based on the households’ attributes (e.g., dwelling type, ownership, number of residents, rooms, ventilation type, etc.) and applied tariffs using a machine learning technique. The extreme learning machine (ELM) is employed in solving the overfitting problem due to low-volume data. The correlation matrix is also constructed to determine the relationship between the household attributes. The ELM model developed in this study extracts the correlation between the input variables in determining energy consumption and also predicts the energy consumption related to low consumption data. The findings indicated that the electricity consumption between the pre-revised tariff year and the revised tariff enforcement year saw a reduction which was consistent in the subsequent years. This was also validated by the paired sample t-test, which showed a significant decrease in electricity consumption for the study period. The analysis also revealed that several household attributes had a relatively high impact on the reduction in the electricity consumption level following the revised tariffs, whereas the majority of the attributes had a moderate impact. In addition to these key findings, the demonstrated pathway adopted in this study is itself a methodological contribution that provides critical information about the sensitivity of the impacts of tariffs on energy consumption with respect to different household attributes. Economic factors being the critical stress need to be blended with existing energy consciousness for positive changes in favor of energy-saving behavior of the household members. The study does not attempt to represent the population of concern, but demonstrates a methodology that would help unleash inherent energy consciousness in favor of sustainable and energy-efficient behavior. Full article

The construction industry is continuously searching for sustainable materials to combat the rapid depletion of global resources and ongoing ecological crises. Biocomposites have recently received global attention in various industries due to their renewability, low cost, and biodegradability. Biocomposites’ potential as a sustainable substitute in construction can be understood by identifying their diverse applications. Moreover, examining their life cycle environmental and economic impacts is important. Therefore, this study is a novel attempt to encompass biocomposites’ construction applications and their environmental life cycle performance. Statistical analysis is done related to the temporal distribution of papers, publishers, literature type and regions of studies. First, this paper reviews the latest research on the applications of natural fiber biocomposites in construction with their key findings. The applications include fiber reinforcements in concrete, external strengthening elements, internally filled hollow tubes, wood replacement boards, insulation, and non-structural members. The second part covers the life cycle assessment (LCA) and cost studies on biocomposites. The life cycle studies are currently rare and require more case-specific assessments; however, they highlight the benefits of biocomposites in cost savings and environmental protection. Finally, this study provides key suggestions for increasing the applicability of biocomposites as sustainable construction materials. Full article

Alzheimer’s disease (AD) is a global health issue that predominantly affects older people. It affects one’s daily activities by modifying neural networks in the brain. AD is categorized by the death of neurons, the creation of amyloid plaques, and the development of neurofibrillary tangles. In clinical settings, an early diagnosis of AD is critical to limit the problems associated with it and can be accomplished using neuroimaging modalities, such as magnetic resonance imaging (MRI) and positron emission tomography (PET). Deep learning (DL) techniques are widely used in computer vision and related disciplines for various tasks such as classification, segmentation, detection, etc. CNN is a sort of DL architecture, which is normally useful to categorize and extract data in the spatial and frequency domains for image-based applications. Batch normalization and dropout are commonly deployed elements of modern CNN architectures. Due to the internal covariance shift between batch normalization and dropout, the models perform sub-optimally under diverse scenarios. This study looks at the influence of disharmony between batch normalization and dropout techniques on the early diagnosis of AD. We looked at three different scenarios: (1) no dropout but batch normalization, (2) a single dropout layer in the network right before the softmax layer, and (3) a convolutional layer between a dropout layer and a batch normalization layer. We investigated three binaries: mild cognitive impairment (MCI) vs. normal control (NC), AD vs. NC, AD vs. MCI, one multiclass AD vs. NC vs. MCI classification problem using PET modality, as well as one binary AD vs. NC classification problem using MRI modality. In comparison to using a large value of dropout, our findings suggest that using little or none at all leads to better-performing designs. Full article

Recently, misinformation and disinformation, as well as fake news, have become global threats to public health owing to their role in spreading viral health hazard information. The growing explosive religious fatalistic views presented on social media and widespread misinformation, disinformation, and fake news can result in detrimental outcomes in adopting protective behavior. The moderating implications of misinformation and religious fatalism can be severe, leading to adverse effects on polio vaccine acceptance. Consequently, this research provides brief empirical evidence on the efficacy of risk communication strategies to address polio vaccine reluctance in a digital age landscape, an area that remains understudied. This research argues that the spread of misinformation, disinformation, fake news, and religious fatalism is not solely the bane of the polio vaccine, but rather represents the absence of risk communication strategies. The study opines that polio vaccine acceptance can be improved using risk communication strategies. Recognizing these risk factors and counter-risk communication strategies, this research tested a theoretical model using the cross-sectional survey design. Overall, data was collected from 2160 parents with children aged below five years. The results, based on structural equation modeling, revealed that public service advertisements are an effective tool to counter the inverse impacts of misinformation, disinformation, fake news, and religious fatalism. Furthermore, the inverse moderating role of misinformation, disinformation, fake news, and religious fatalism has been verified to potentially diminish polio vaccine acceptance. These results suggest that healthcare providers must identify and address all forms of digitally disseminated information that encumbers public health behaviors. Accordingly, this research recognized the utilization of evidence-based strategic communication campaigns to cultivate and encourage the literacy necessary to counter health hazard information, including misinformation. This study’s findings will benefit health and other concerned authorities in utilizing strategic communication on different media platforms to reduce or eradicate the polio endemic. Full article

Synthetic plastics are causing serious environmental and health problems due to which the concept of developing biodegradable food packaging has gained considerable attention. In this study, extraction of gelatin from chicken feet was optimized followed by characterization of gelatin. Chicken feet gelatin was used to develop biodegradable nanocomposite films by the incorporation of chitosan (CS) and zinc oxide (ZnO) nanoparticles (NPs). Gelatin nanocomposite films were used to increase the shelf-life of fresh grapes by determining the browning index, weight loss, and microbial profile of fresh grapes. A high yield (7.5%) of gelatin and Bloom strength (186 g) were obtained at optimized extraction conditions (pretreatment with 4.2% acetic acid and extraction at 66 °C for 4.2 h). Electrophoretic analysis of gelatin revealed the presence of α (130–140 kDa) and β chains (195–200 kDa), whereas a Fourier transformed infrared (FTIR) spectrometer confirmed the presence of amide A and B and amide I, II, and III. Incorporation of ZnO NPs in a gelatin–CS matrix improved the barrier and the mechanical and the thermal properties of films. Gelatin nanocomposite films with 0.3% ZnO NPs significantly reduced the weight loss (23.88%) and the browning index (53.33%) of grapes in comparison to control treatments. The microbial count in artificially inoculated grapes wrapped in gelatin nanocomposite films remained below 4 log CFU/mL until the fifth storage day in comparison to control treatments. The gelatin from poultry byproducts such as chicken feet can serve as an efficient biopolymer to develop biodegradable food packaging to enhance the shelf-life of perishable food products. Full article

Energy performance contracts (EPC) can address economic sustainability challenges associated with residential energy retrofitting projects, including funding limitations, poor quality of project delivery, and landlord-tenant dilemma. Literature has overlooked the impact of weighted average cost of capital (WACC) and funding sources in EPC planning. However, the WACC, stakeholder priorities, and uncertainties can alter the project outcomes. This study proposes a Monte-Carlo simulation based non-linear multi-objective optimization approach to address the aforementioned challenges. A case study conducted in British Columbia indicated that the maximum overall project profitability can vary between $18,035 and $20,626 with decision priorities. The overall project profitability can vary over 9% due to uncertainties. The project profits can change over $3000 due to changes in the WACC. These observations confirmed the criticality of accounting for WACC, stakeholder priorities, and uncertainties in EPC planning. The risk of compensating for the performance compromises and profits increases simultaneously for the energy services company with the increasing contract periods, while it is inverse for the owners. Therefore, the contract period must be decided considering the profit expectations and risk tolerance of the stakeholders. Extended contract periods allow lower capital contributions from the building owners, potentially solving the principal-agent disputes in rental buildings. Full article

Several factors over the years have contributed to stigma in public transport. Many studies have highlighted the need to make the transport system more equitable both from economic and gender perspectives. This study attempts to demonstrate how the perceptions of public transport users and non-users are stigmatized from social and cultural standpoints. Thus, it identifies the social and cultural stigma-induced barriers embedded with the use and people’s general perception about the public bus service, taking SAPTCO (Saudi Public Transport Company) as a case study. The study results suggest that privacy concern is the primary cause of stigma. Most of the users are unwilling to ride with their families as SAPTCO does not account for gender needs (e.g., privacy, travel convenience, safety, comfort, etc.). Moreover, people from the high-income classes are more stigmatized against this ridership. A fuzzy inference system (FIS) model is used to analyze the survey questionnaire responses and understand what stigma means for the public bus service. Expert opinions are employed to generate “if–then” rules of the FIS models. Sensitivity of the defined fuzzy model is conducted to different aspects of the ridership. The study results further suggest that “inconvenience” poses the highest impact while “feeling safe”, “privacy”, “fare”, “timing”, and “comfort” are found to be the medium impact-making variables for stigma. The stigma-defining variables would be critical for the public bus service to improve its service quality and help (re-)design the policies that would attract a high amount of ridership. Some solutions are suggested in the end that would complement, strengthen, and promote the current SAPTCO service. The demonstrated methodology of this study would be relevant and adaptive to any relevant context to improve public transportation service and pertaining policies. Full article

Water contaminated with highly hazardous metals including arsenic (As) is one of the major challenges faced by mankind in the present day. To address this pressing issue, hybrid beads were synthesized with various concentrations of zero valent iron oxide nanoparticles, i.e., 20% (FeCh-20), 40% (FeCh-40) and 60% (FeCh-60) impregnated into a polymer of chitosan. These hybrid beads were employed as an adsorbent under the optimized conditions of pH and time to facilitate the efficient removal of hazardous arsenic by adsorption cum reduction processes. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer- Emmett-Teller BET, a porosity test and wettability analysis were performed to characterize these hybrid beads. The porosity and contact angle of the prepared hybrid beads decreased with an increase in nanoparticle concentration. The effects of various adsorption factors such as adsorbent composition, contact period, pH value and the initial adsorbate concentration were also evaluated to study the performance of these beads for arsenic treatment in contaminated water. FeCh-20, FeCh-40 and FeCh-60 have demonstrated 63%, 81% and 70% removal of arsenic at optimized conditions of pH 7.4 in 10 h, respectively. Higher adsorption of arsenic by FeCh-40 is attributed to its optimal porosity, hydrophilicity and the presence of appropriate nanoparticle contents. The Langmuir adsorption kinetics described the pseudo second order. Thus, the novel beads of FeCh-40 developed in this work are a potent candidate for the treatment of polluted water contaminated with highly toxic arsenic metals. Full article

The energy consumption of buildings contributes significantly to global greenhouse gas (GHG) emissions. Energy use for space and water heating in buildings causes a major portion of these emissions. Natural gas (NG) is one of the dominant fuels used for building heating, emitting GHG emissions directly to the atmosphere. Many studies have been conducted on improving energy efficiency and using cleaner energy sources in buildings. However, implementing carbon capture, utilization, and storage (CCUS) on NG building heating systems is overlooked in the literature. CCUS technologies have proved their potential to reduce GHG emissions in fossil fuel power plants. However, their applicability for building-level applications has not been adequately established. A critical literature review was conducted to understand the feasibility and viability of adapting CCUS technologies to co-function in building heating systems. This study investigated the technical requirements, environmental and socio-economic impacts, and the drivers and barriers towards implementing building-level CCUS technologies. The findings indicated that implementing building-level CCUS technologies has significant overall benefits despite the marginal increase in energy consumption, operational costs, and capital costs. The information presented in this paper is valuable to academics, building owners and managers, innovators, investors, and policy makers involved in the clean energy sector. Full article