We report a superspreading event of severe acute respiratory syndrome coronavirus 2 infection initiated at a bar in Vietnam with evidence of symptomatic and asymptomatic transmission, based on ...ministry of health reports, patient interviews, and whole-genome sequence analysis. Crowds in enclosed indoor settings with poor ventilation may be considered at high risk for transmission.
Addition of flow fields to carbon paper electrodes in a vanadium redox flow battery (VRFB) can improve the peak power density through uniform distribution of electrolyte in the electrodes. However, ...it is unclear whether flow fields have a similar effect with graphite felt electrodes, as VRFBs with felt electrodes reported in literature show a large anomaly in obtained power density. In this work, we evaluate three flow fields; viz. serpentine, interdigitated and conventional (without flow pattern) type with felt electrodes and compare their performance with a serpentine flow field using carbon paper electrodes under identical experimental conditions. The conventional flow field provides highest energy efficiency (75%) followed by serpentine (64%) and interdigitated (55%) at 0.2 A cm−2 attributable to the deteriorating electrolyte distribution in the electrodes. Computation fluid dynamic simulations confirm the experimental finding of worsening electrolyte distribution (conventional < serpentine < interdigitated). A power density of 0.51 W cm−2 at 60 mL min−1 flow rate is obtained for serpentine and conventional flow fields with felt electrodes; comparable to the highest power density reported in literature for high performing zero-gap flow field architecture. This paper gives comprehensive insights on flow fields for VRFBs that can be extended to other flow batteries.
•Graphite felts with/without flow field show high power density like carbon papers.•Mass transport issues in VRFBs with various flow fields have been quantified.•SFF offers better depth of discharge at low SOC.•IFF performs better at low flows and currents and exhibits lowest pressure drop.•CFF shows least mass transport resistance and has the highest pressure drop.
The construction site layout planning is an activity that establishes the temporary facility location, thereby enhancing the efficiency of the construction. Recently, safety enhancement plays a ...significant role in construction site layout planning. This paper aims in developing an optimal construction site layout planning by fulfilling three main objectives, namely minimum cost facility, minimum risk of safety facility and minimum noise pollution. In addition to this, this paper also proposes a fuzzy-based bee colony optimization (FBCO) algorithm for tuning
ρ
and
τ
parameters so as to obtain a feasible and optimal solution. Also, this FBCO algorithm is employed to solve the construction site layout problem by satisfying the multi-objective function. Then, an FBCO-CLP approach is employed in obtaining a final optimal construction site layout plan. Moreover, the performance analysis of FBCO employs five benchmark functions to examine the effectiveness of the system for numerous aspects. Finally, a case study utilizes a residential building for verifying the proposed approach containing 13 temporary facilities. The experimental result reveals that the proposed FBCO-CSLP approach provides an optimal layout plan with minimum cost, noise pollution and safety risk facilities. Moreover, the comparative analysis is done by comparing the proposed approach with various other approaches such as ANN, GA, PSO, ABC and DE for three different types of facilities, namely cost facility, safety facility risk and noise facility. The experimental analysis reveals that the proposed approach provides better performances when compared with all other approaches.
This research examines the role of hotel employees' satisfaction with their organization's COVID-19 responses in reducing their perceived job insecurity (PJI) and maintaining their job performance ...(JP). We conducted two studies using an explanatory sequential mixed-methods design. The results indicated that employees' satisfaction with organization COVID-19 responses (SOCV19R) positively influences JP and moderates (1) the positive association between perceived health risk associated with COVID-19 (PHRCV19) and PJI and (2) the negative link between PJI and JP. Unexpectedly, PHRCV19 was found to positively affect JP, and the moderating effect of SOCV19R on the relationship between PHRCV19 and JP was significant and positive. We also found that PJI has a mediating role in the PHRCV19-JP relationship. This study fills a significant gap in hospitality research by exploring the role of the organization's crisis responses in tempering the impact of perceived health risk of a global health crisis on hotel employees. Theoretically, this research revealed that employees' SOCV19R helps raise JP, mitigate the positive influence of PHRCV19 on PJI and the negative impact of PJI on JP, and strengthen the positive effect of PHRCV19 on JP.
Under the lens of conservation of resources and social exchange theories and job demands-resources model, this research aimed at advancing the knowledge regarding the role of trade union support ...(TUS) in tempering the impact of perceived health risk of COVID-19 (PHRCV19) on frontline hotel employees (FHEs)' job insecurity and emotional exhaustion (EE), a research topic that is thus far overlooked. An explanatory sequential mixed-method design was adopted. Quantitative data collected through a two-wave survey from 291 FHEs were performed to test the hypotheses using SmartPLS, and 16 in-depth interviews were then analyzed to gain a deeper understanding of the quantitative study's findings and identify the right ways to enhance employee resilience during COVID-19. We found that (1) TUS directly reduces perceived job insecurity (PJI), (2) PHRCV19 has a positive effect on PJI and EE, and (3) PJI positively influences EE; at the same time, PJI partially mediates the PHRCV19-EE relationship. However, the moderating role of TUS on the impact of PHRCV19 on PJI, and that of PJI on EE, is insignificant. This research also provided practical implications helping reduce FHEs' PJI and EE.
Due to globalization expansion, corporate social responsibility (CSR) is no longer an unfamiliar concept in emerging markets. In the case of Vietnam, its implementation will be influenced by several ...factors, including ethical leadership. Drawing upon the stakeholder theory, this study develops and tests a serial mediation model to explain how CSR and firm reputation can connect ethical leadership to enhanced firm performance. The PLS-SEM results from survey data collected from 653 mid- and top-level managers from large companies in Vietnam indicate that ethical leadership positively influences CSR, which, in turn, results in enhanced firm reputation and firm performance. This study contributes to research on the intersection between CSR and leadership in the context of emerging markets. This study also provides some managerial implications for Vietnamese firms striving to promote ethical leadership to achieve CSR outcomes.
Ethical leadership, corporate social responsibility, firm reputation, firm performance, Vietnam
•Perceived risk associated with COVID-19 positively affects employees’ OCB.•Workplace safety management practices (WSPs) positively influence employees’ OCB.•WSPs negatively impact on employees’ ...perceived job insecurity.•WSPs do not decrease the employees’ perceived risk associated with COVID-19.•Emphasize the power of WSPs as well as measures to reassure employees psychologically.
How do organizations and employees react to the COVID-19 pandemic? Can workplace safety management practices (WSPs) maintain employees’ organizational citizenship behavior (OCB) in this time of global health crisis? Can employees’ perceptions of the risk associated with COVID-19 and job insecurity mediate the WSPs–OCB relationship? Drawing upon social exchange and protection motivation theories, this research aims to answer such questions. Analyzing the survey data from 501 Vietnamese employees using SmartPLS software, we find that WSPs positively influence the OCB and negatively influence the perceived job insecurity. Furthermore, the perceived risk associated with COVID-19 positively affects perceived job insecurity and OCB. Unexpectedly, in the context of Vietnam, a developing country with a collectivist culture, WSPs increase the employees’ perceived risk associated with COVID-19 instead of reducing their fear. Also, employees’ perceptions of job insecurity are not statistically correlated with OCB. In addition, we reveal a partial mediating role of the perceived risk associated with COVID-19 in the WSPs–OCB relationship. This research highlights the power of WSPs as well as measures to psychologically reassure employees during the pandemics.
•A novel combined cooling and power generation system is presented.•Application of the Low-Temperature Heat Source for cogeneration purposes is stated.•Energy and exergy analysis is conducted for the ...combined system.•Exergoeconomic analysis for the proposed system is carried out.•Key parameters influence on the cycle performance is conducted.
The energy consumption and the emission of greenhouse gases have been motivated researchers toward using renewable energy sources for the development of a sustainable society. Low-temperature heat sources like geothermal sources can be a desirable option to produce the demanded power, cooling, heating, and other byproducts. In the present literature, a novel combined cooling and power generation system is presented which is an internal integration of the Kalina Cycle and the absorption refrigeration cycle. The system operates using the low-temperature heat source. The thermodynamic and thermoeconomics analysis is carried out using Engineering Equation Solver software. Besides, considering the mathematical modeling, the parametric investigation is implemented to evaluate the effect of the key parameters on the sum unit cost of the products. Based on the obtained results, the cooling and power generation system can provide the net output power of 158.3kW and the cooling capacity of 1084kW. The results indicate that the system is most appropriate for cooling provision rather than for power generation aims. The energy and the exergy efficiencies and the net power of the combined cycle obtained 41.33%, 27.47%, and 158.3kW respectively. The sum unit cost of the product cooling, power, and total system are respectively evaluated 148.5$/GJ, 97.16$/GJ, and 19.44$/GJ. The minimum and maximum values for the rate of exergy destruction cost belong to the pump and absorber, respectively. The parametric analysis delivered some valuable results such as a drop in the sum unit cost of the net power, cooling output, and overall system by increasing the generator hot pinch point temperature difference, an increase in the overall system sum unit cost of the products with increment in the low-temperature heat source inlet temperature, and rising in the sum unit cost of the net power, cooling output, and the overall system with an increase in the evaporator temperature.
The insect bacterium Wolbachia pipientis is being introgressed into Aedes aegypti populations as an intervention against the transmission of medically important arboviruses. Here we compare Ae. ...aegypti mosquitoes infected with wMelCS or wAlbB to the widely used wMel Wolbachia strain on an Australian nuclear genetic background for their susceptibility to infection by dengue virus (DENV) genotypes spanning all four serotypes. All Wolbachia-infected mosquitoes were more resistant to intrathoracic DENV challenge than their wildtype counterparts. Blocking of DENV replication was greatest by wMelCS. Conversely, wAlbB-infected mosquitoes were more susceptible to whole body infection than wMel and wMelCS. We extended these findings via mosquito oral feeding experiments, using viremic blood from 36 acute, hospitalised dengue cases in Vietnam, additionally including wMel and wildtype mosquitoes on a Vietnamese nuclear genetic background. As above, wAlbB was less effective at blocking DENV replication in the abdomen compared to wMel and wMelCS. The transmission potential of all Wolbachia-infected mosquito lines (measured by the presence/absence of infectious DENV in mosquito saliva) after 14 days, was significantly reduced compared to their wildtype counterparts, and lowest for wMelCS and wAlbB. These data support the use of wAlbB and wMelCS strains for introgression field trials and the biocontrol of DENV transmission. Furthermore, despite observing significant differences in transmission potential between wildtype mosquitoes from Australia and Vietnam, no difference was observed between wMel-infected mosquitoes from each background suggesting that Wolbachia may override any underlying variation in DENV transmission potential.
While prior studies in human resource management have investigated how employee outcomes have been affected in high‐risk workplaces, this study stands out by examining this issue through the role ...played by COVID‐19 as a specific stressor. We explained how employees' perceived health risks due to COVID‐19 (CV19PHR) and perceived workplace safety practices (PWSPs) affected job performance via burnout and how PWSPs moderated the CV19PHR–burnout and CV19PHR–JP relationships. We also examined how mindfulness moderated the direct effects of CV19PHR and PWSPs on burnout and JP and the indirect effects of CV19PHR and PWSPs on JP via burnout. We performed three studies using an explanatory sequential mixed‐method design. In study 1, a three‐phase survey with 987 respondents was conducted to test the hypotheses. In study 2, by analyzing verbatim from 22 informants, the findings of study 1 and some main points concerning mindfulness and PWSPs were explained. In study 3, using data from 12 informants, we investigated how COVID‐19 affected individuals differently compared with other high‐risk workplaces and whether the impact of COVID‐19 on individuals was curvilinear. We demonstrated that employees' CV19PHR was positively correlated with burnout, negatively influencing JP. Moreover, PWSPs reduced burnout, which adversely affected JP. Interestingly, PWSPs positively moderated the CV19PHR–burnout relationship but not the CV19PHR–JP relationship. We also found that mindfulness moderated the CV19PHR–burnout and PWSPs–burnout relationships. Furthermore, mindfulness significantly moderated the mediating effects of burnout on the CV19PHR–JP and PWSPs–JP relationships.
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