Search Results (4,623)

Thermal insulation is a reliable strategy for achieving optimal thermal comfort in built environments and is among the most effective energy-saving measures. Currently, environmentally friendly insulation materials produced from plant and animal fibers constitute a significant component of the building industry, largely due to their minimal embodied energy and concerns about certain synthetic insulation materials’ potential adverse health effects. The main objective of the present study is to encourage and facilitate the utilization of environmentally friendly thermal insulation materials derived from biological sources, including vegetal and animal fibers, to improve thermal comfort and consequently reduce energy consumption in buildings. The study attempts to simulate the indoor air temperature profiles of a single building constructed using locally sourced materials and insulated in a series of stages with the aforementioned insulation materials. Firstly, insulation is applied exclusively to the roof. Secondly, the insulation is applied to the remaining wall surfaces. Alternatively, the insulation is applied to both the roof and the wall surfaces simultaneously. The objective is to ascertain the optimal combination of bio- and geo-insulating materials to achieve thermal comfort in buildings constructed with local materials in tropical climates. The Gauss-Seidel iterative method was employed to solve the energy equations that had been written on the walls and roof of the building. The equations were then discretized using the nodal method. To ascertain the thermal comfort of the simulated buildings, a comparison was made of the indoor air temperatures. The results of the simulations demonstrated that the utilization of wood fiber, reed panels, and straw bales as insulation materials led to a notable enhancement in comfort levels across all five building types, with an average increase of 17.5%. Among these materials, wood fiber emerged as the most effective insulation option, reducing temperatures by up to 19%. Its integration into the sheet metal-clad Banco building would be particularly advantageous. The findings demonstrate that the simultaneous insulation of walls and roofs with natural fiber thermal insulation materials markedly reduces indoor air and wall temperatures in buildings by up to 19% in comparison to uninsulated walls and roofs. Full article

This study focused on the novel ventilation solution used in the control room of an electric submersible pump on a jack-up offshore platform, with the core objective of exploring the advantages of tunnel ventilation over the traditional ceiling-mounted ventilation system. At the beginning of the research, a three-dimensional physical model of the room’s air conditioning and ventilation system was constructed using Rhino 7 software. Subsequently, the computational fluid dynamics software Airpak 3.0 was employed to conduct detailed thermodynamic calculations on the model. Based on this, the study meticulously compared the performance of the two ventilation systems from multiple perspectives: one aspect examined the airflow and temperature distribution through temperature contour maps, velocity vector maps, and airflow streamlines; another focused on the comfort level of personnel, as reflected in the key indicators of the predicted mean vote and predicted percentage dissatisfied. The results demonstrated that tunnel ventilation is highly effective in reducing the indoor temperature and significantly improving personnel comfort. Further optimization analysis revealed that, under specific inlet conditions, namely when the inlet velocity reaches 1.16 m/s and the inlet temperature is 17 °C, the most ideal ventilation effect can be achieved, thereby fully and effectively meeting human thermal comfort requirements. Overall, the findings of this study not only provide a novel solution for the environmental control system design of offshore platforms but also lay a solid scientific foundation for continued exploration in related fields, offering a reliable reference for future research. Full article

Several guidelines provided by the World Health Organization as well as frameworks in the scientific literature suggest focusing on the built environment, i.e., indoor and outdoor spaces, including urban furniture, for promoting public health as it acts as a promoter of healthy lifestyles. The paper presents part of the results emerged from the HNH research project, which addresses the topic of neighborhood health at a systemic transdisciplinary and trans-scalar level of the project (macro-, meso-, up to micro-level). In particular, the results at the micro-scale of the urban furniture design are presented, which are related to the following research questions: (i) what are the strategic design requirements of street furniture for a healthy neighborhood and (ii) what are the micro-scale design scenarios for orienting the choices of the public administration in the creation of a healthy neighborhood. Through the use of a conceptual framework developed in the research, as a tool both to measure the quality of the built environment and to develop participatory design activities and co-design workshops, the research arrives at the categorization of urban furniture into domains, sub-domains, and related products categories, for each of which design strategies and scenarios are defined. The results highlight the potential and importance of urban furniture design in promoting a healthy built environment, underlining the strategic role of tangible products as healthy touchpoints to promote healthy lifestyles. Full article

Optimising existing knowledge sets and encouraging the integration of interdisciplinary study findings can facilitate the advanced functions of biodiversity required for sustainable urban landscapes. Urban Green Spaces (UGS) can reach across an urban landscape, including indoor environments. The existing and traditional knowledge sets and practices for urban development and greening provide extensive and pertinent guidance; they are however variably implemented. More recent and advanced knowledge sets where properly utilised can optimise and provide advanced function. When adequately brought together, advanced sustainability for urban landscapes can significantly improve global sustainability performance. This article uses the final step of classic grounded theory to contextualise, verify and define refined wilding as a substantiating concept for functional biodiversity as theory for urban landscapes and for sustainable urban development. Refined wilding works toward wild refined UGS that functionally connect across an urban space and landscape, including positive influential flows with grey and transparent spaces. Where used to guide urban design, strategies, vision and goals this concept can provide (i) a conceptual framing that optimises and encourages an organisation of interdisciplinary and advanced knowledge, improving and advancing sustainable urban development, and (ii) a specificity, and overarching and comprehensive guidance for various UGS types toward the positive outcome of functional biodiversity. Functionally biodiverse UGS and landscapes require lower maintenance and perform at an advanced level for human health, economic development, the natural environment, and built or paved environments and landscapes. In turn, addressing how human activity and modification of urban landscapes can significantly degrade human health and the natural environment, or underachieve. Refined wilding (i) substantiates functional biodiversity as a positive outcome for urban landscapes, with a balance between ecological functions and functions for human populations; (ii) considers quality, function, and connectivity of and between UGS and spaces where UGS could be introduced or improved; (ii) enables an improvement, and addresses common barriers to UGS accomplishing advanced functions for urban sustainability; (iii) encourages urban wilding by functional native and non-native selections, and natural and semi-natural UGS; (iv) positively influences and is influenced by grey (built environment) and transparent spaces (blue/aquatic and air). Full article

Aspergilli and other molds are prevalent in the environment and are an important cause of opportunistic infections and seasonal allergies in susceptible patients. This study determined species distribution of various molds in outdoor/indoor air in and around a major hospital and performed antifungal susceptibility testing and molecular fingerprinting of environmental and clinical Aspergillus fumigatus isolates in Kuwait. Sampling for the isolation of molds was performed for a 17-month-period from the water/indoor air of medical/surgical wards/ICUs and outdoor air. Molds were identified by phenotypic characteristics and/or by the PCR-sequencing of rDNA/β-tubulin/calmodulin genes. Antifungal susceptibility testing was done by Etest. Fingerprinting was performed by nine-loci-based microsatellite analysis. A total of 6179 isolates were obtained from outdoor (n = 4406) and indoor (n = 1773) environments. These included Cladosporium spp. (n = 2311), Aspergillus spp. (n = 1327), Penicillium spp. (n = 1325), Paecilomyces spp. (n = 473), Alternaria spp. (n = 218), Bipolaris spp. (n = 133), and other molds (n = 392). Fingerprinting data revealed heterogeneity among clinical and environmental A. fumigatus and shared genotypes among outdoor air and hospital environmental isolates. Itraconazole-resistant A. fumigatus isolates with TR₃₄/L98H mutations in Cyp51A were also recovered from outdoor air (n = 1), a hospital environment (n = 3), and clinical samples (n = 2). More than 15 fungal genera and all four Aspergillus (Nigri, Flavi, Fumigati, and Terrei) sections and nine rare aspergilli were detected. The isolation frequency was higher during the peak allergy season of October/November. The presence of shared genotypes among outdoor air and the hospital environment including triazole-resistant A. fumigatus suggests a reservoir for invasive infections among susceptible hospitalized patients. Full article

The Malaysian Department of Occupational Safety and Health (DOSH) reported that noise-induced hearing loss (NIHL) accounted for 92% of occupational diseases in 2019. To address this, accurate risk assessment is crucial. The current noise evaluation methods are complex and time-consuming, relying on manual calculations and field measurements. An easy-to-use, open-source noise simulator that directly compares the output with national standards would help mitigate this issue. This research aims to develop an advanced noise evaluation tool to assess and predict unregulated workplace noise, providing tailored safety recommendations. Using a representative plant layout, the Sound Pressure Level (SPL) is calculated using MATLAB’s ray tracing propagation model. The model simulates all possible transmission paths from the source to the receiver to derive the resultant SPL. A noise simulation application featuring a graphical user interface (GUI) built with MATLAB’s App Designer (version: R2024a) automates these computations. The simulation results are validated against the DOSH’s safety standards in Malaysia. Additional safety metrics, such as the recommended maximum exposure time and the required Noise Reduction Rating (NRR) for hearing protection, are calculated based on the SPLs for hazardous locations. The simulation algorithm’s functionality is validated against manual calculations, with an average deviation of just 3.06 dB, demonstrating the model’s precision. This tool can assess and predict indoor noise levels, provide information on optimal exposure limits, and recommend necessary protective measures, ultimately reducing the risk of NIHL in factory environments. It can potentially optimise plant floor operations for existing and new facilities, ensuring safer shift operations and reducing worker noise hazard exposure. Full article

In recent years, repeated outbreaks of airborne viruses have normalized human coexistence with these viruses. The complex turbulence and vortices generated by different fan types and operation modes affect virus removal effectiveness. This paper reviews the potential impact and actual effectiveness of different fans in mitigating indoor virus transmission, highlighting their advantages and limitations. Downward rotating ceiling fans can rapidly dilute virus concentration (21–87%) in the breathing zone due to jet cores, with efficiency depending on rotational speed and particle diameter. However, the reprocessing problems of large particles being deposited on surfaces, and small particles settling and rebounding into the air remain unresolved. Upward-rotating ceiling fans do not contribute to indoor virus removal. Exhaust fans generate a negative-pressure environment, which helps expel viruses quickly. But improper vortex zones can increase virus retention time 16–40 times. Air-apply fans effectively dilute and transport viruses only when delivering airflow exceeding 0.5 m/s directly into the breathing zone. Additionally, combined fan strategies remain underexplored, despite potential benefits. This review underscores the need for standardized definitions of particle removal effectiveness and calls for further research on how climatic conditions and thermal comfort influence fan-based interventions. Full article

Thermal comfort is a fundamental goal of architecture aiming at protecting individuals from harsh weather conditions. In Nigeria’s savanna climate zone, such as Kaduna, poor indoor thermal comfort leads to over-reliance on air-conditioning systems. There is limited research on the application of passive design strategies in the Nigerian savanna climate, which creates a barrier to their widespread implementation in residential buildings. In response to the increased awareness of climate change and the need for sustainable design, this study explores the potential of passive design strategies, focusing on the combination of rooftop insulation and reflective materials with mechanical ventilation as a means of improving indoor thermal comfort solutions. This study conducted a 3-day field experiment of typical dwellings in Kaduna, a major city in the Nigerian savanna climate zone. The data collected from this experiment served as the basis for a simulation study using EnergyPlus software, which tested and evaluated 3 different strategies: passive design (roof insulation + reflective materials), mechanical ventilation, and a combination of passive design and mechanical ventilation. This study highlights the potential for passive design strategies to provide a more sustainable, cost-effective solution, reducing dependence on air conditioning while supporting indoor comfort. Additionally, the research methodology and insights gained offer a basis for developing future building codes in Nigeria that emphasize sustainable practices. Such codes would guide architects, builders, and policymakers in designing homes that respond to local climate needs and align with broader sustainability goals. Further research could explore additional passive measures, including advanced window technologies, shading, and natural ventilation, to maximize sustainable residential design potential in tropical savanna climates. Full article

Large-scale engineering projects frequently involve pit excavation and wetland landfill operations, resulting in significant silt accumulation that occupies land and adversely affects the environment. Curing technology offers a solution for reusing this waste silt. In this study, straw ash and calcium carbide slag are proposed as effective curing agents for silt soil. Various indoor tests were conducted to evaluate the mechanical properties of the cured silt soil, while X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze its mineral composition and micro-morphology. The results showed that increasing the curing agent dosage significantly improved soil strength. Specifically, at a 10% dosage, the California bearing ratio (CBR) value increased to 18.7%, which is 13.4 times higher than untreated silt soil and exceeds road specifications by 8%. At a 20% dosage, the unconfined compressive strength (UCS) value reached 1.38 MPa, meeting the ≥0.8 MPa requirement for roadbeds. Based on economic considerations, a 20% dosage of straw ash–calcium carbide slag was selected as optimal. Microscopic analysis revealed that the addition of these agents promoted the formation of hydrated calcium silicate, filling pores and enhancing the mechanical properties of the cured soil, resulting in a more dense and stable structure. Full article

The negative ion air purifier (NIAP) has been used for capturing particulate matter. Nevertheless, the knowledge on its effectiveness in removing other air pollutants such as ammonia gas remains limited. In this study, the effect of an NIAP for indoor ammonia gas removal was evaluated through a series of experimental studies. The applicability and different influencing, operating, and environmental factors on the ammonia gas removal performance were firstly investigated by conducting a series of experiments. Then, in order to understand the performance of the NIAP and the spatial distribution of ammonia gas and other by-products, indoor field measurements of ammonia gas, ozone, and negative ion concentrations in a real bathroom were performed for different cases with the NIAP turned on and off. The results indicated that negative ions were effective in reducing ammonia gas concentration. The operating and environmental factors including upstream wind speed, degree of operating voltage, and initial ammonia gas concentration have great influences on the ammonia gas removal efficiency of the NIAP. The highest removal efficiency can reach to 95.8%, when the upstream wind speed was 0.8 m/s and the degree of operating voltage was at gear 3 (3.0 kV). The purification efficiency of ammonia gas for the NIAP could reach up to 80%. Full article

Topography estimation is essential for autonomous off-road navigation. Common methods rely on point cloud data from, e.g., Light Detection and Ranging sensors (LIDARs) and stereo cameras. Stereo cameras produce dense point clouds with larger coverage but lower accuracy. LIDARs, on the other hand, have higher accuracy and longer range but much less coverage. LIDARs are also more expensive. The research question examines whether incorporating LIDARs can significantly improve stereo camera accuracy. Current sensor fusion methods use LIDARs’ raw measurements directly; thus, the improvement in estimation accuracy is limited to only LIDAR-scanned locations The main contribution of our new method is to construct a reference ground plane through the interpolation of LIDAR data so that the interpolated maps have similar coverage as the stereo camera’s point cloud. The interpolated maps are fused with the stereo camera point cloud via Kalman filters to improve a larger section of the topography map. The method is tested in three environments: controlled indoor, semi-controlled outdoor, and unstructured terrain. Compared to the existing method without LIDAR interpolation, the proposed approach reduces average error by 40% in the controlled environment and 67% in the semi-controlled environment, while maintaining large coverage. The unstructured environment evaluation confirms its corrective impact. Full article

Objectives: The objective of this narrative literature review was to highlight all dental procedures attributable to sectoral waste and to consider possible alternatives in line with the concept of sustainable development. Methods: An extensive search of electronic databases, including the Cochrane Oral Health Group Specialized Register, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, PubMed, EMBASE, and Google Scholar. Search words included ‘Green Dentistry’, ‘Dental Pollution’, ‘Pollutants and Dentistry’, ‘Disinfectants and Dentistry’, and ‘High-tech Dentistry’. All of them allowed an assessment of the impact of dental practice on the external environment, and new frontiers currently applied or possibly applicable for green dentistry were included in the study. Non-full-text papers, animal studies, studies in languages other than English, and studies not related to the topic under consideration were excluded. Results: According to the inclusion criteria, 76 papers were selected for the study. The topics analyzed were the impact of dental practice on the outdoor environment, currently applied and potentially applicable principles of green dentistry, and the ‘Four Rs’ model (Rethink, Reduce, Reuse, and Recycle). Conclusions: With the limitations of the present study, the concept of green dentistry could be applicable provided that the measures already taken to reduce indoor and outdoor risk factors are continued and improved. Full article

Biocontrol microbes are environment friendly and safe for humans and animals. To seek biocontrol microbes effective in suppressing Fusarium oxysporum is important for tomato production. F. oxysporum is a soil-borne pathogen capable of causing wilt in numerous plant species. Therefore, we found a biocontrol bacterium with an excellent control effect from the rhizosphere soil of plant roots. In this work, we focus on two parts of work. The first part is the identification and genomic analysis of the biocontrol bacterium Y-4; the second part is the control efficiency of strain Y-4 on F. oxysporum. For this study, we identified strain Y-4 as Bacillus velezensis. It is an aerobic Gram-positive bacterium that can secrete a variety of extracellular enzymes and siderophores. Strain Y-4 also contains a large number of disease-resistant genes and a gene cluster that forms antibacterial substances. In addition, we found that it significantly inhibited the reproduction of F. oxysporum in a culture dish. In the indoor control effect test, after treatment with strain Y-4 suspension, the disease index of tomato plants decreased significantly. Furthermore, the control efficiency of the plants was 71.88%. At the same time, Y-4 bacterial suspension induced an increase in POD and SOD enzyme activities in tomato leaves, resulting in increased plant resistance. Taken together, strain Y-4 proves to be an effective means of controlling F. oxysporum in tomatoes. Full article

Carbon monoxide (CO) is a toxic gas, and faulty gas appliances or solid fuel burning with incomplete combustion are possible CO sources in households. Evaluating household CO exposure models and measurement studies is key to understanding where CO exposures may result in adverse health outcomes. This assists the assessment of the burden of disease in high- and middle-income countries and informs public health interventions in higher-risk environments. We conducted a literature review to identify themes that characterise CO exposure in household dwellings. A keyword-structured search using literature databases was conducted to find studies published in the period of 1 January 2010–5 June 2024. We focused on studies from high- and middle-income countries, excluding animal and biomass studies, and narratively synthesised themes. We identified 5294 papers in the literature search and included 22 papers from thirteen countries in the review. Most measured CO levels were below the WHO or country guidance levels, with sporadic peaks of measured CO linked to fuel-burning activities. To understand CO exposure in households, we identified sixteen themes grouped into five main categories: dwelling characteristics, source characteristics, temporal variation, environmental characteristics, and socioeconomic status of occupants. Seasonal variation (temporal variation), size of room and ventilation (dwelling characteristics), and cooking and outdoor CO levels (source characteristics) had the most evidence. These themes characterising CO exposure in household dwellings are important to aid the development of indoor exposure models and for understanding where CO exposures result in adverse health outcomes. These themes should be validated by household CO monitoring studies, which will enable the identification of higher-risk household dwellings and inform public health actions. Full article

This paper presents a detailed step-by-step design and construction of an indoor and outdoor air quality monitoring device, composed of electronic sensors capable of measuring gases such as Carbon Monoxide (CO), Nitrogen Dioxide (NO₂), Ozone (O₃), in addition to measuring temperature and humidity, as well as concentrations of PM2.5 and PM10 particulate matter suspended in the environment. The device features the ESP32 microprocessor board that integrates IoT wireless connectivity via Wi-Fi, which allows for longer processing time and wireless communication. To evaluate the accuracy of the Q-air device, measurements were taken at strategic sites in the city of Barranquilla, which were compared with data from stationary monitoring stations in the city, the results obtained by Q-Air showed a margin of error less than 1.6%, demonstrating accuracy and efficiency. Full article