Search Results (26)

Despite the well-documented health risks of noise pollution, its impact remains overlooked mainly in life cycle assessment (LCA). This study introduces a methodological innovation by integrating both traffic and construction noise into the LCA framework for concrete construction, providing a more holistic and realistic evaluation of environmental and health impacts. By combining building information modeling (BIM) with LCA, the method automates material quantification and assesses both environmental and noise-related health burdens. A key advancement is the inclusion of health-based indicators, such as annoyance and sleep disturbance, quantified through disability-adjusted life years (DALYs). Two scenarios are examined: (1) a comparative analysis of concrete versus timber flooring and (2) end-of-life options (reuse vs. landfill). The results reveal that concrete has up to 7.4 times greater environmental impact than timber, except in land use. When noise is included, its contribution ranges from 7–33% in low-density regions (Darwin) and 62–92% in high-density areas (NSW), underscoring the critical role of local context. Traffic noise emerged as the dominant source, while equipment-related noise was minimal (0.3–1.5% of total DALYs). Timber slightly reduced annoyance but showed similar sleep disturbance levels. Material reuse reduced midpoint environmental impacts by 67–99.78%. Sensitivity analysis confirmed that mitigation measures like double glazing can cut noise-related impacts by 2–10% in low-density settings and 31–45% in high-density settings, validating the robustness of this framework. Overall, this study establishes a foundation for integrating noise into LCA, supporting sustainable material choices, environmentally responsible construction, and health-centered policymaking, particularly in noise-sensitive urban development. Full article

The fracturing pump serves as a critical piece of equipment in enhancing oil and gas recovery rates. However, under the coupled action of high-pressure fluid pulsation circulation in the pump body and the vibration of fracturing equipment, the bolts connecting the fracturing pump and fracturing manifold flange are prone to fatigue failure. In this paper, a three-dimensional finite-element model of the threaded bolt connection structure at the fracturing pump outlet end with a fine thread structure was established, and the measured vibrational displacement of the fracturing pump under different driven modes was used as the load to obtain the internal stress state of the full-thread bolt and the double-headed bolt used in the fracturing operation site. Based on the stress state, the fatigue life of the two types of bolts under various loading conditions was then simulated using the Brown—Miller fatigue damage criterion. The results indicate that for bolts of the same structural type, the maximum stress and stress variation amplitude increase in the sequence of the diesel-driven, single-motor-driven, and dual-motor-driven methods. Additionally, under the same load, the stress of the full-thread bolt is lower than that of double-headed bolt. The fatigue life analysis results show that under the vibrational load of diesel drive, the full-thread bolt can obtain a longer fatigue life of approximately 2042.89 h. However, under the load of dual-motor-driven method, the fatigue life of double-headed bolt is the lowest, only 717.46 h. A comparison with the fatigue life of bolts in actual engineering projects indicates that the predicted fatigue life of the bolts is consistent with the actual service life, which can provide effective guidance for the inspection and maintenance of fracturing pump equipment. Full article

Transformers in the distribution network must have their carbon emissions analyzed in order to meet the “double carbon” goal. Using an oil-immersed distribution transformer as the research object, this paper develops a “cradle-to-grave” carbon accounting model. A life cycle assessment (LCA)-based methodology is proposed to account for carbon emissions and total energy demand over the full life cycle and further analyze the carbon emissions within each stage. A case study is presented using data from a 200 kVA transformer manufactured by a transformer plant in Xinjiang. According to the data, there are 112.18 t of carbon emissions and 798.21 GJ of total energy consumed. Distribution network transformers have carbon emissions of 282 kg, 782 kg, 122.96 kg, 11,079.64 kg, and −88.6 kg throughout the manufacture and manufacturing stage, transportation stage, construction and installation stage, operation stage, and waste recycling stage, respectively. There are 4.12 GJ, 9.06 GJ, 1.34 GJ, 785.97 GJ, and −0.28 GJ in total energy requirements. According to the study, which covered 99.03% of the entire life cycle, the operation stage had the largest percentage of carbon emissions. In addition to streamlining the production process and using more energy-efficient equipment, the waste recovery stage successfully decreased the environmental impact of carbon emissions. Sensitivity analysis shows that the silicon steel sheet and transformer oil has a significant impact on the carbon emissions of distribution network transformers during the life cycle, and the higher the grade of silicon steel sheet, the lower the carbon emissions, and the synthetic ester transformer oil has the most comprehensive performance and the lowest carbon emissions. Full article

Background: This longitudinal study aimed to evaluate whether prior engagement in a physical exercise program correlated with enhanced perceptions of quality-of-life components among older adults during the COVID-19 lockdown period. Methods: The cohort comprised elderly individuals (aged ≥ 65 years) who had previously partaken in a 12-week randomized controlled trial investigating the effects of a mixed aerobic–anaerobic, moderate-intensity exercise program. Participants’ health-related quality of life was assessed using the Short Form Health Survey-12 item (SF-12) at the beginning of the initial trial and, again, one year later during the COVID-19 lockdown. In the exercise group, 44 participants were included, while the control group consisted of 49 participants, with computer-based, double-blind randomization conducted in Cagliari, Italy. The differences in scores for each SF-12 item between the two groups from T0 to T1 were compared using one-way ANOVA with Bonferroni corrections. Data were analyzed using the Statistical Package for Social Sciences (SPSS) version 27. Results: No statistically significant differences were observed on average by age (exercise group vs. control group 72.20 ± 4.78 vs. 72.91 ± 4.77; F = 0.513, p = 0.476). A decrease from T0 to T1 towards a better score on the SF-12 was observed in the exercise group compared to the control group in item 1 (F = 67.463, p < 0.0001); in item 5 (F = 4.319, p = 0.041); item 8 (F = 4.269, p = 0.041); item 9 (F = 10.761, p = 0.001); item 10 (F = 170.433, p < 0.001); and item 11 (F = 4.075, p = 0.046). Conclusions: The results suggest that participation in a moderate physical exercise program one year prior may have equipped older adults with better coping mechanisms to navigate the stress and isolation imposed by the COVID-19 lockdown, as reflected by their enhanced scores on quality-of-life components pertaining to mental well-being. Exercise may confer a protective effect against the adverse psychological impacts of stressful events like the pandemic, even among older adults with chronic conditions. This study underscores the potential benefits of exercise interventions for promoting quality of life and preventing mood disorders in the elderly population. Full article

The technology of obtaining porous nanostructures is based on ecological organosilicon materials and their uses in some spheres of human life, for example, for medical preparations, for thermal insulation of building structures and industrial equipment, and for cleaning. The purpose of this study was to establish correlations between various experimental parameters (shear stress, speed pulsations, temperature, viscosity, and processing time) and the rheological characteristics of suspensions obtained by the method of liquid-phase dispersion; it was a study of hydrodynamic effects and the processes of heat and mass exchange in liquid systems during the liquid-phase dispersion of hydrogel monoliths by means of discrete-pulse activation in a special rotary apparatus. The dehydration of hydrogels was carried out by two methods: convective drying in a layer and spraying in the coolant flow. Experiments have shown that the key parameters for obtaining stable homogeneous suspensions are a synergistic combination of concentration factors and processing time. To obtain adsorbents in the form of pastes with specified adsorption properties and a monolith size of up to 300 μm, the optimal parameters were a hydrogel concentration of 70% and a processing time in the double-recirculation mode. Xerogels obtained by convective drying are a polydisperse mixture of strong monoliths and fragile aggregates. In contrast, xerogel monoliths obtained by spray drying show great homogeneity in terms of dispersion and strength characteristics. The rheological parameters of the hydrogel dispersions, which depend on the concentration and hydrodynamic treatment modes, are the dominant factors affecting the moisture extraction during drying. This study marks the first investigation into the resilience of porous organosilicon structures against the influence of intense turbulence fields and mechanical stresses experienced within the rotor apparatus during suspension production. Full article

The rapid increase in the global population is contributing to the urgent challenges we face in ensuring the sustainability of our planet. This demographic shift, which gained momentum in the 1990s, is closely linked to a surge in natural disasters, both in terms of their frequency and severity. The quest for resources and improved quality of life, including the need for housing and essential services, has compounded these challenges. With the world’s population projected to double by 2050, and approximately two-thirds of this population expected to reside in urban areas, we are facing a complex web of interconnected issues that will significantly magnify the impacts of climate change-induced disasters. It is imperative that we build resilient cities capable of withstanding and adapting to these changes. However, the growing complexity of urban services and the necessity for integrated management raise questions about the preparedness of these resilient cities to comprehend and address the multifaceted challenges posed by climate change. In response to these critical concerns, this study endeavors to address the intersection of resilience and climate change. We propose the development of a Smart Resilient City Assessment Framework, comprising two core components: resilience re-evaluation and smartness evaluation. Each component consists of eight essential steps. The culmination of these steps results in a semi-quantitative index that accurately reflects the city’s position regarding resilience and smartness in the face of climate change-related disasters. To demonstrate the framework’s practicality and suitability, we present results from a hypothetical scenario focusing on water supply management, a critical aspect of climate change adaptation. The framework equips city managers with the necessary tools to re-evaluate their cities’ resilience, evaluate their capacity to address climate change-induced challenges, and make informed decisions on integrating resilience and smart solutions to pave the way for a more sustainable and climate-resilient future. Full article

The rising concerns about electric and electronic equipment waste (WEEE) come from the rapid increase in demand for appliances and the decreasing lifetimes of equipment. Setting a sustainable WEEE management system that exploits this secondary resource is paramount to maximize resource efficiency, mitigate its environmental impact, and stimulate the circular economy. This paper aims, for the first time, to quantify the material flow expected from recycling the generated WEEE, propose the number of plants required to recycle this secondary resource, and outline the expected economic and environmental benefits that could be achieved from recycling operations. The findings of material flow calculations show that the amount of steel, copper, and aluminum is predominant in the WEEE composition. Also, the expected metal content in WEEE in 2022 is approximately 26 kt, 3.3 kt, and 2.5 kt, respectively. These are expected to substantially increase to approximately 109 kt, 11.9 kt, and 9 kt for the three metals in 2050, respectively. Other valuable metals are doubling their quantities between 2022 and 2050 to reach approximately 1133 kg silver and 475 kg gold. Approximately, four treatment plants are required to recover these materials in 2030 with relative installation costs of USD 100 million. The forecasted financial revenues of recovering materials included in WEEE and indicators for environmental impact based on life cycle assessment (LCA) are calculated. The results of this study can serve as a preliminary reference for future usage in guiding effective planning for WEEE recycling and sustainable management in the country. Full article

Nosocomial coronavirus disease 2019 (COVID-19) is a major airborne health threat for inpatients. Architecture and ventilation are key elements to prevent nosocomial COVID-19 (NC), but real-life data are challenging to collect. We aimed to retrospectively assess the impact of the type of ventilation and the ratio of single/double rooms on the risk of NC (acquisition of COVID-19 at least 48 h after admission). This study was conducted in a tertiary hospital composed of two main structures (one historical and one modern), which were the sites of acquisition of NC: historical (H) (natural ventilation, 53% single rooms) or modern (M) hospital (double-flow mechanical ventilation, 91% single rooms). During the study period (1 October 2020 to 31 May 2021), 1020 patients presented with COVID-19, with 150 (14.7%) of them being NC (median delay of acquisition, 12 days). As compared with non-nosocomial cases, the patients with NC were older (79 years vs. 72 years; p < 0.001) and exhibited higher mortality risk (32.7% vs. 14.1%; p < 0.001). Among the 150 NC cases, 99.3% were diagnosed in H, mainly in four medical departments. A total of 73 cases were diagnosed in single rooms versus 77 in double rooms, including 26 secondary cases. Measured air changes per hour were lower in H than in M. We hypothesized that in H, SARS-CoV-2 transmission was favored by short-range transmission within a high ratio of double rooms, but also during clusters, via far-afield transmission through virus-laden aerosols favored by low air changes per hour. A better knowledge of the mechanism of airborne risk in healthcare establishments should lead to the implementation of corrective measures when necessary. People’s health is improved using not only personal but also collective protective equipment, i.e., ventilation and architecture, thereby reinforcing the need to change institutional and professional practices. Full article

Due to the operation conditions and system characteristics of the essential service water system of nuclear power plants, water hammer pressure fluctuates in each transient process. In order to further analyze the characteristics of the water hammer and the harm this can cause to system equipment, this paper uses one-dimensional transient computing software to simulate the water hammer characteristics of the system under different operating conditions and at different water levels. The instantaneous pressure data of water hammer in the essential service water system were used as input conditions for fatigue analysis of components, and the fatigue damage of at-risk parts was calculated. The results show that the pressure fluctuation due to single pump outage is greater than that due to single pump start-up and the start-up of double pumps. The maximum pressure of the system under the design flood level is greater than that of other water levels, and the maximum pressure of the system under each working condition is 3.87 MPa. The most at-risk part of the system pressure fluctuation is the return valve, followed by the valve after a bend in a pipe and the tee pipe fitting. In the whole system, the joint of the main branch of a tee pipe experiences the greatest fatigue damage, and the theoretical fatigue life is 127.55 years. Full article

The structural collapse of a street lighting pole represents an aspect that is often underestimated and unpredictable, but of relevant importance for the safety of people and things. These events are complex to evaluate since several sources of damage are involved. In addition, traditional inspection methods are ineffective, do not correctly quantify the residual life of poles, and are inefficient, requiring enormous costs associated with the vastness of elements to be investigated. An advantageous alternative is to adopt a distributed type of Structural Health Monitoring (SHM) technique based on the Internet of Things (IoT). This paper proposes the design of a low-cost system, which is also easy to integrate in current infrastructures, for monitoring the structural behavior of street lighting poles in Smart Cities. At the same time, this device collects previous structural information and offers some secondary functionalities related to its application, such as meteorological information. Furthermore, this paper intends to lay the foundations for the development of a method that is able to avoid the collapse of the poles. Specifically, the implementation phase is described in the aspects concerning low-cost devices and sensors for data acquisition and transmission and the strategies of information technologies (ITs), such as Cloud/Edge approaches, for storing, processing and presenting the achieved measurements. Finally, an experimental evaluation of the metrological performance of the sensing features of this system is reported. The main results highlight that the employment of low-cost equipment and open-source software has a double implication. On one hand, they entail advantages such as limited costs and flexibility to accommodate the specific necessities of the interested user. On the other hand, the used sensors require an indispensable metrological evaluation of their performance due to encountered issues relating to calibration, reliability and uncertainty. Full article

Due to various factors such as manufacturing, assembly and operation, the motor air gap will be uneven in the circumferential direction, resulting in the air gap eccentricity having a longer air gap on one side and a shorter air gap on the other side, which affects the normal operation and service life of the motor. This paper analyzed and compared the applicability of linear and nonlinear calculation methods of unbalanced magnetic pull. Based on the method of finite element analysis, the unbalanced magnetic pull of motor rotor under static eccentricity, dynamic eccentricity and compound eccentricity faults were calculated, and the influence of eccentricity on unbalanced magnetic pull was compared, respectively. The results showed that when the motor has static eccentricity, the main components of unbalanced magnetic pull on the rotor are zero frequency and twice the electrical frequency. When the motor has dynamic eccentricity, the unbalanced magnetic tension component of the rotor is mainly frequency conversion. When the motor has two faults at the same time, the unbalanced magnetic pull has zero frequency, rotating frequency and double electric frequency components at the same time. With the increase in the relative eccentricity, the frequency components of the unbalanced magnetic pull under the three faults increase. An air gap eccentricity fault widely exists in motor equipment. When the unbalanced magnetic pull increases to a certain extent, the rotor will be pulled towards the stator, causing the occurrence of rub-impact phenomenon, and seriously threatening the safe operation of the system. In this paper, the numerical analysis method and finite meta-computing method were used for the first time to analyze and compare the unbalanced magnetic pull on the rotor of permanent magnet synchronous motor under three kinds of air gap eccentricity faults. The results showed that the characteristic frequency amplitude of the unbalanced magnetic pull calculated by the two methods is relatively close. Therefore, it is of great significance to carry out calculation and analysis of the unbalanced magnetic pull force under the air gap eccentric fault of the motor. Full article

The Hellisheidi geothermal power plant, located in Iceland, is a combined heat and power double-flash geothermal plant with an installed capacity of 303.3 MW of electricity and 133 MW of hot water. This study aimed to elucidate the environmental impacts of the electricity and heat production from this double-flash geothermal power plant. In this vein, firstly, the most updated inventory of the plant was generated, and secondly, a life-cycle assessment approach based on the exergy allocation factor was carried out instead of applying the traditionally used allocations in terms of mass and energy. The functional unit was defined as the production of 1 kWh of electricity and 1 kWh of hot water for district heating. The life-cycle stages included the (i) construction, (ii) operation (including abatement operations and maintenance), and (iii) well closure of the geothermal plant. All of the life-cycle stages from construction to dismantling were considered. Finally, the results on the partitioning of the environmental impact to electricity and heat with exergy allocations showed that most of the impact should be charged to electricity, as expected. Furthermore, the distribution of the environmental impacts among the life-cycle stages determined that the construction stage was the most impactful for the electricity and heat production. This result was attributable to the large consumption of steel that was demanded during the construction of the geothermal power plant (geothermal wells, equipment, and buildings). Impacts due to the abatement stage demonstrated that this stage satisfactorily reduced the total impact attributed to the three life-cycle stages of the geothermal power plant. Full article

Echelon usage is an important usage and control method for double-life equipment considering calendar life, which can improve the utilization rate of equipment life and give full play to the economic benefits of the equipment. However, the life indicator considered by the most common echelon usage method is single, and most methods evaluate the echelon usage through the echelon uniformity of working life. The conclusions obtained are limited for the usage and control of double-life equipment, so it is necessary to study the life evaluation method considering calendar life. In this paper, by analyzing the life consumption law of double-life equipment, the recursive method is used to calculate the controllable life range in the process of echelon usage. The evaluation method of working life distribution considering calendar life is proposed. The equipment life reserve is evaluated according to the unit task quantity of the equipment. The results show that the new method can quickly analyze the equipment beyond the usage and control range, evaluate the distribution of working life more accurately, reflect the shortage of equipment reserve life, and has guiding significance for the usage and control of equipment. Full article

Advancements in energy technologies created a new application for gas turbine generators, which are used to balance load. This usage also brought new challenges for maintenance because of harsh operating conditions that make turbines more susceptible to random failures. At the same time, reliability requirements for energy equipment are high. Reliability-centered maintenance based on forecasting the remaining useful life (RUL) of energy equipment, offers improvements to maintenance scheduling. It requires accurate forecasting methods to be effective. Defining stages in energy equipment operation allows for the improvement of quality of data used for training. At least two stages can be defined: normal operation and degradation process. A new method named Head move—Head move is proposed to robustly identify the degradation process by detecting its starting point. The method is based on two partially overlapping sliding windows moving from the start of operation to the end of life of the energy equipment and Kruskal-Wallis test to compare data within these windows. Using this data separation, a convolutional neural network-based forecasting model is applied for RUL prediction. The results demonstrate that the proposed degradation process identification (DPI) method doubles the accuracy when compared to the same forecasting model but without degradation process identification. Full article

This research developed an effective environmental temperature control system for homes and buildings. The study used a photovoltaic panel (PV) and developed a solar installation with thermosiphon circulation, which has a flat solar collector and heat-insulating translucent glass with double glazing with reduced pressure. The coolant is made of thin-walled corrugated stainless pipe. The heat from the solar flux heats the liquid removed from the collector, and cold water from the siphon enters its place. There is a constant circulation of heat, which increases heat transfer efficiency by eliminating additional partitions between the panel and thermal insulation. We have also developed a solar system control controller, which includes an electronic unit with six sensors. The six sensors are controlled by the STM32 programmable Logistics Integrated circuit (FPGA), designed to monitor the entire solar system, and the drives include power relays. The performance of the photovoltaic panel and the room’s temperature change are calculated during both the simulation and testing of the controller. The standard error was 20% compared to other controllers. During the experiment, the consumption savings amounted to about 1% due to the control signal in the controller, which has a significant impact on the service life of the equipment. Full article