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• Family caregivers of the surgical ICU patients whom we surveyed during COVID-19 pandemic reported worse anxiety and sadness than those who were surveyed during pre-pandemic period. • Supports are necessary to mitigate anxiety and sadness of family caregivers who are under visitation restriction due to COVID-19 pandemic. • During pandemics, ICU clinicians need to implement alternative strategies to provide sufficient information to family caregivers, especially on updates regarding their family members" medical conditions. Since the COVID-19 pandemic, restricting family visits in the ICU has increased concerns regarding negative psychosocial consequences to patients and families. To compare the quality of life, depressive symptoms, and emotions in family caregivers of ICU patients before and during the COVID-19 pandemic, and to explore families' perceptions and suggestions for the visitation. A cross-sectional descriptive survey was conducted in 99 family caregivers of adult surgical ICU patients from an urban academic medical center in South Korea (February to July 2021). The WHO's Quality of Life-BREF, Center for Epidemiologic Studies Depression, and Visual Analogue Scale were used to assess quality of life, depressive symptoms, and emotions, respectively. The Family Perception Checklist was used to assess families' perceptions and suggestions about the visitation restriction. Results were compared with the data from our previous survey (n = 187) in 2017. Family caregivers were mostly women (n = 59), adult children (n = 43) or spouse (n = 38) of patients with mean age of 47.34 years. Family caregivers surveyed during the pandemic reported worsening sadness (54.66 ± 28.93, 45.58 ± 29.44, P = 0.005) and anxiety (53.86 ± 30.07, 43.22 ± 29.02, P = 0.001) than those who were surveyed in. While majority of families were satisfied with the visitation restrictions (86.9%), only 50.5% were satisfied with the amount of information provided on the patient's condition. Visitation restriction is necessary during the COVID-19 pandemic despite sadness and anxiety reported in caregivers. Hence, alternative visitation strategies are needed to mitigate psychological distress and provide sufficient information to ICU family caregivers. [ABSTRACT FROM AUTHOR]

Hydrates and wax are common hazards for oil and gas pipelines. The formation of hydrates and wax can lead to pipeline blockage, which may cause accidents incurring significant assets, safety, and environmental losses. The current study aims to develop a risk-based flow assurance model for hydrates and wax. The probabilistic models are developed to assess the likelihood of hydrate formation, hydrate blockage, and wax blockage. The proposed models use thermo-hydraulic data to estimate the probability of pipeline blockage hazards. The developed models are tested against the published studies and lab data. Application of the models is demonstrated using case studies. The models would help develop and implement pipeline design and intervention strategies to ensure a safer continued operation pipeline system. [ABSTRACT FROM AUTHOR]

• This study investigates chemical accidents that occurred between January 2008 and June 2018 in South Korea. • 76.1% of chemical accidents were caused by human error in South Korea. • Large-scale enterprises experienced the largest number of industrial accidents during maintenance work. • Fire and explosion accounted for 72% of all CPI accidents, of which 32.4% were ignited by static electricity. • Chemical accidents mostly occurred in storage tanks, chemical reactors, and mixing tanks. Major accidents in the chemical process industries are relatively rare, but the resulting harm to workers, property loss, business interruption, and the environment are very serious. This study investigates chemical accidents that occurred between January 2008 and June 2018 in South Korea, and proposes ways to prevent similar accidents from occurring by analyzing the main causes of these accidents. Nine core concepts were drawn from the analyses comparing chemical accidents in South Korea: (1) current casualties by type of worker, (2) how the scale of the enterprise affects the disaster, (3) chemical accidents by type of occurrence, (4) analysis of ignition sources, (5) chemical accidents by CPI facilities, (6) human and technical error, (7) chemical accidents by work situation, (8) chemical accidents by non-compliance of process safety management (PSM) standards, and (9) chemical accidents by hazardous materials. Although there have been no recent occurrences of large chemical accidents since 2017 due to various factors, our results indicate that the past frequency of such accidents area serious concern in South Korea. Understanding the root causes of these accidents can help to prevent the recurrence of similar accidents and to strengthen preventative measures in chemical plants. [ABSTRACT FROM AUTHOR]

Carbon emissions are a significant driver of global climate change in today's world. A central concern in discussing carbon emissions is the level of uncertainty associated with them. This study aims to assess the feasibility of using the Mean Squared Error (MSE) as a point estimation measure and confidence interval (CI) as an interval estimation measure to quantify the uncertainty surrounding carbon emissions. To achieve this goal, the bootstrap and Markov Chain Monte Carlo (MCMC) sampling methods were used, utilizing both classical and Bayesian inference methods to uncover the true parameter value. In the context of Bayesian inference, a 2-chain MCMC method proved to be the optimal choice for generating posterior distributions and accurately estimating the true parameter of the distribution θ. The analysis also shows that, while a CI is valuable as an evaluative measure, it does not inherently provide a quantified form of uncertainty and should not be used for quantitative uncertainty assessment. Instead, the Relative Standard Error (RSE) emerges as a promising quantitative measure for capturing the uncertainty of θ , while the percentage uncertainty offers a qualitative perspective. These combined measures provide a comprehensive toolkit for computing and communicating the uncertainty in carbon emission and emission factor values. This reinforces a move towards incorporating transparent uncertainty metrics, ensuring that stakeholders have access to reliable and accurate carbon emission values. [ABSTRACT FROM AUTHOR]

There has been an increase in environmental degradation associated with the use of fossil fuels in an attempt to meet the ever-increasing demand for electricity. Therefore, alterative renewable energy sources have garnered the attention of many researchers globally; hydrogen is an important example due to its eco-friendly nature. For hydrogen to be used as an energy source, it has to first be compressed. The explosion of high-pressure hydrogen vessels has been the driver of most accidents associated with its use. To prevent explosions, thermally activated pressure relief devices (TPRDs) are used to release hydrogen. The TPRD release orientations in a tunnel, which is a confined space, were investigated in this study based on a high-pressure release of hydrogen. In addition, we also propose an evacuation and safety protocol in the event of such an accident. In addition, the dynamics associated with the release of hydrogen were analyzed based on vehicle type. We found that in passenger cars and buses, hydrogen is released from the bottom and top, respectively. The dispersion range in this study was simulated based on a hydrogen concentration of 4%, in which air currents, including those from jet fans in the tunnel, are considered. The results confirm that passenger cars are barely affected by the jet fan airflow, and backward release facilitates evacuation and secures a safety zone more effectively compared with vertical emission. Meanwhile, upward releases were significantly affected by the jet fan. Overall, release in the airflow direction, regardless of the tunnel location, was confirmed to be effective in the context of evacuation and securing safety zones for buses. • Consequence analysis for Thermally-activated Pressure Relief Devices of HFCVs. • Thorough CFD simulations to help the decision-making for emergency responders. • Open space and confined space hazards comparison for different vehicle types. • Open space and confined space hazards comparison for different TPRD release angles. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a new approach for the optimal facility siting considering the uncertainty of toxic release in one of the installed facilities. The proposed formulation incorporates the effect of wind speed, wind direction and atmospheric stability to calculate the risk of death via probit functions and Monte Carlo simulation. The overall problem is initially modeled as a disjunctive program where the Cartesian coordinates of each new facility for siting and cost-related variables are the main unknowns to determine. Then, the convex hull approach is used to reformulate the problem as a mixed integer nonlinear program (MINLP). The numerical difficulties are shown in a case study where multiple optimal layouts have been found. In general, the numerical results demonstrate the potential of this approach to improve the process layout design activity. [Copyright &y& Elsevier]

• Effectiveness of scrubbers to reduce explosion risk of ZrO 2 ALD by-product was evaluated. • Burn-wet scrubber makes the by-product more thermally stable. • Burn-wet scrubber treatment is to combust the organic residues remaining in the by-product. • Burn-wet scrubber was shown to be more effective at reducing the risk than dry scrubber. In processes of manufacturing semiconductors, reactive by-products (as a form of fine powder, i.e., dust) are deposited in pipes installed on post processing and exhaust systems, potentially involving a considerable explosion risk. In this study, the effectiveness of scrubber methods (e.g., dry scrubber and burn-wet scrubber) to mitigate the risk was evaluated. To this end, three by-products generated from a ZrO 2 atomic layer deposition (ALD) process were collected from semiconductor manufacturers, which were treated with different methods (i.e., no treatment, treatment using dry scrubber, and treatment using burn-wet scrubber), and their characteristics were analyzed and compared. Particle size measurements of the by-products proved that the burn-wet scrubber treatment less decreased their particle size than the dry scrubber treatment. The burn-wet scrubber treatment made the by-product thermally stable, confirmed by thermogravimetric analysis. Fourier-transform infrared spectroscopy of the by-products before and after the scrubber treatments showed that burn-wet scrubbing of the by-product decreases surface functionalities that play a role in explosion. Dust explosion testing proved that robustness of explosion of the untreated by-product is about 7 times higher than the by-product treated with the burn-wet scrubber. Based on the results of this study, it would be suggested that burn-wet scrubber is a useful treatment method to decrease the explosion risks caused by dust by-products generated from ALD in semiconductor manufacturing processes. [ABSTRACT FROM AUTHOR]