Effects of Precipitation on the Air Quality Index, PM2.5 Levels and on the Dry Deposition of PCDD/Fs in the Ambient Air

The effects of 9 precipitation events in Suzhou City in Anhui Province, China, on the air quality index (AQI), PM2.5, and dry deposition flux of PCDD/Fs (polydibenzo-p-dioxins and polydibenzofurans) were investigated. A total of 7 precipitation events were positive contributes to the reduction of AQI;among them, the AQI were between 23 and 216, with an average of 75, the PM2.5 concentrations were between 5.0 and 169 mu g m-3, with an average of 25 mu g m-3, while the total-PCDD/F-TEQ dry deposition flux ranged from 149 to 1034 pg WHO2005-TEQ m-2 day-1 and averaged 315 pg WHO2005-TEQ m-2 day-1. By comparing the average AQI and PM2.5, respectively, during and after rainfall with that before rainfall, the results indicated that the average reduction fractions of AQI were 26% and 44%, respectively, while those of PM2.5 were 58% and 43%. In addition, the effect of precipitation on the average reduction fraction of total PCDD/F-TEQ dry deposition flux was 31%. However, in the other 2 AQI elevation events, the AQI were between 23 and 100, and averaged 51;when comparing the average AQI and PM2.5 concentrations, during and after the rain with that before the rain, the increases in AQI were 42% and 49%, respectively, while the increases in PM2.5 concentration were 26% and 29%, respectively. The above results show that, on the whole, rain and snow improved the air quality. This is because rainwater removes particles or dissolved gaseous pollutants from the atmosphere and brings aerosols to the ground. However, in some cases, the increase of source emissions and atmospheric vertical convection, the effect of precipitation or air humidity increased the AQI and elevated the concentration of PM2.5, and dry deposition flux of PCDD/Fs. The results of this study provide useful information for both scientific communities and air quality management.

Performance of the African stock market amid COVID-19 global health crisis: empirical analysis using four events

The study employs the market model and event study approach with four events to examine the performance of the African stock market amid COVID-19 global health crisis. We use daily stock market data from 14 African countries (as a proxy for the African market) spanning September 2019 to June 2021 and COVID-19 data to estimate average abnormal returns for Africa. The results show significant positive average abnormal returns in Africa when the WHO announced COVID-19 as a global health epidemic. The events of infections and deaths generated significant negative average abnormal returns while the event of vaccination did not generate any significant average abnormal returns in the market. In as much as pandemics are unpredictable, the African market quickly recovers as depicted by COVID-19;therefore, we recommend to investors, speculators, and portfolio managers not to quickly exit the continent during pandemics. Copyright © 2023 Inderscience Enterprises Ltd.

Impact of COVID-19 Pandemic on Indian Stock Market Sectors

The start of the COVID-19 pandemic and official lockdown announcements had created uncertainty in global business operations. For the first time, the Indian stock market has significantly impacted. India is one of the most important rising economies in the world and has seen the value of its crucial stock indices plummet by about 40%. There are several studies on the impact of the pandemic on the stock market, but very few studies have focused on a comparative analysis of the first and second COVID-19 pandemic waves. The Fama French model of an event study is used to analyze the response of various sectoral indices during the pandemic. Although all industries were briefly damaged, the financial industry was the hardest hit. Industries such as pharmaceuticals, consumer products, and information technology had favorable or minor effects in both waves. The second wave had an insignificant impact compared to the first one, clearly indicating optimism and normality in the market despite the looming pandemic threat. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Impact of the COVID-19 outbreak on stock returns of Indian healthcare and tourism sectors

The rapid spread of the novel coronavirus pandemic (COVID-19) has adversely impacted global economies and stock markets. This study employs an event study methodology to assess the impact of COVID-19 on stock returns in the healthcare (66 stocks) and tourism (39 stocks) sectors in Indian markets surrounding two events: a) the first COVID-19 case reported in India and b) the announcement of a nationwide lockdown. The findings indicate that investors' reactions to both events were distinct and asymmetric in healthcare and tourism sectors. The tourism sector stocks react more negatively to the second event than the first, with -2.46% vs. -0.59% event day abnormal returns, respectively. The corresponding figures for healthcare sector stocks are -0.68% and -0.16%, respectively. As expected, pandemic events had a minor negative impact on the healthcare sector. Surprisingly, the tourism industry did not react negatively to the first event. Investors in the tourism industry underreacted to the first reported case;they could not predict the potential consequences and then overreacted to the lockdown announcement. The findings support the behavioral finance theory of underreaction and overreaction, particularly in stressful situations. The study has implications for investors and money managers looking for profitable investment opportunities due to temporary dislocations in stock prices caused by investors' irrational reactions to certain black swan events. © Mayank Joshipura, Ashu Lamba, 2022.

Front-line employees' perceived COVID-19 event strength and emotional labor in the service industry: A moderated mediation model.

COVID-19 pandemic has brought enormous challenges to employees worldwide, and thus, it is important to understand whether, how, and when perceived COVID-19 event strength can influence employees' work-related outcomes. Drawing on event system theory and affective events theory, this study examined the effect of perceived COVID-19 event strength on front-line service employees' emotional labor, namely, surface acting and deep acting, through the mediating role of anxiety. In addition, it explored job insecurity as a moderator in the relationship between perceived COVID-19 event strength and anxiety. This study analyzed two-wave data (N = 191) collected from front-line employees in the service industry and found that anxiety mediated the relationship between perceived COVID-19 event strength and surface acting but not deep acting, and that job insecurity moderated the relationship between perceived COVID-19 event strength and anxiety and the indirect effect of perceived COVID-19 event strength on surface acting but not on deep acting via anxiety. Implications and directions for future research are also discussed.

The Paradoxical Effects of COVID-19 Event Strength on Employee Turnover Intention.

As a global pandemic, the novel coronavirus (COVID-19) has brought enormous challenges to employees and organizations. Although numerous existing studies have highlighted that the COVID-19 pandemic is a stressful event and empirically proved its detrimental effect on employee turnover intention, few scholars have noted that this pandemic can deteriorate the external economic and employment environment simultaneously, which may further complicate employees' intentions to leave or stay in the current organization. Drawing on event system theory and social cognitive theory, this study aims to uncover two potential cognitive mechanisms of the complex impact of COVID-19 event strength on employee turnover intention. To examine the proposed model, this study employed a three-wave and time-lagged research design and collected data from a sample of 432 employees of four Chinese companies from different industries. The findings indicated that COVID-19 event strength was negatively related to perceived external employability, and ultimately curbed employee turnover intention. Yet, COVID-19 event strength also negatively predicted perceived organizational growth, thus influencing employees to exhibit intentions to quit. Moreover, organizational identification not only attenuated the positive effect of perceived external employability on turnover intention but also amplified the negative impact of perceived organizational growth on turnover intention. Further, organizational identification moderated the indirect effects of COVID-19 event strength on turnover intention through perceived external employability and perceived organizational growth. This study provided a comprehensive insight into scholars' understanding of the COVID-19 downstream outcomes.

Effect of Reduced Emissions from Thermal Power Plants in China on Local Air Quality Improvement

In September 2021, China encountered the shortage of coal and emission activity shrunk to the lowest it had been since February 2020, when coronavirus lockdowns paralyzed the economy. Despite social and economic concerns, this event has brought unexpected positive consequences for environmental quality. In this study, we investigated the impact of restricted thermal power plants operations on local air quality is investigated. For this purpose, social statistics, satellite observations, ground-based air quality measurements, and meteorology data were analyzed to estimate the spatio-temporal characteristics of air pollutants. As a result, significant reductions in the concentrations of air pollutants were found. It was about 11.13% lower than the reduced concentration due to the coronavirus lockdowns period in China. Compared to the average value during the normal year for 2015-2019, large decreased values of SO2 (-38.81%), CO (-24.78%), NO2 (-54.26%), PM 10 (-51.60%), and PM2.5 (-56.35%) were measured in Seoul, Korea. Satellite observation data confirm that these large drop in air pollution levels occurred in both countries, serving as a valuable proof of the emission control impact on local air quality. Moreover, the easterly wind along with the increased precipitation rate in China could affect the wet deposition and dilution of air pollutants.

The impact of COVID-19 on turnover intention among hotel employees: A moderated mediation model

This study examines the influence of COVID-19 event strength on the turnover intention of hotel employees by incorporating perceived operating performance and job insecurity as mediators and hotel size as a moderator. A moderated mediation model was employed to test the relationship between COVID-19 event strength and turnover intention. The study reveals that COVID-19 event strength might not significantly affect turnover intention through perceived operating performance, likely affecting job insecurity perception. We infer that such a finding might result from a series of policies implemented by authorities to prevent job insecurity perception of hotel employees during the COVID-19 pandemic. Furthermore, we also reveal that small- and middle-sized hotels mitigate the effect of job insecurity on turnover intention somewhat different from our expectations. We infer that most of the entrepreneurs and employees in such hotels are from the same town and unlikely to intensify the effect of job insecurity on turnover intention because of close friendships among them. This finding is closely related to cultural factors in China and has rarely been discussed in the existing literature.

Spatio-Temporal Characteristics of Air Quality Index (AQI) over Northwest China

In recent years, air pollution has become a serious threat, causing adverse health effects and millions of premature deaths in China. This study examines the spatial-temporal characteristics of ambient air quality in five provinces (Shaanxi (SN), Xinjiang (XJ), Gansu (GS), Ningxia (NX), and Qinghai (QH)) of northwest China (NWC) from January 2015 to December 2018. For this purpose, surface-level aerosol pollutants, including particulate matter (PMx, x = 2.5 and 10) and gaseous pollutants (sulfur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O-3)) were obtained from China National Environmental Monitoring Center (CNEMC). The results showed that fine particulate matter (PM2.5), coarse particulate matter (PM10), SO2, NO2, and CO decreased by 28.2%, 32.7%, 41.9%, 6.2%, and 27.3%, respectively, while O-3 increased by 3.96% in NWC during 2018 as compared with 2015. The particulate matter (PM2.5 and PM10) levels exceeded the Chinese Ambient Air Quality Standards (CAAQS) Grade II standards as well as the WHO recommended Air Quality Guidelines, while SO2 and NO2 complied with the CAAQS Grade II standards in NWC. In addition, the average air quality index (AQI), calculated from ground-based data, improved by 21.3%, the proportion of air quality Class I (0-50) improved by 114.1%, and the number of pollution days decreased by 61.8% in NWC. All the pollutants' (except ozone) AQI and PM2.5/PM10 ratios showed the highest pollution levels in winter and lowest in summer. AQI was strongly positively correlated with PM2.5, PM10, SO2, NO2, and CO, while negatively correlated with O-3. PM10 was the primary pollutant, followed by O-3, PM2.5, NO2, CO, and SO2, with different spatial and temporal variations. The proportion of days with PM2.5, PM10, SO2, and CO as the primary pollutants decreased but increased for NO2 and O-3. This study provides useful information and a valuable reference for future research on air quality in northwest China.

The Curvilinear Relationship Between Career Calling and Work Fatigue: A Moderated Mediating Model.

Drawing on the job demands-resources (JD-R) model and event system theory (EST), this study constructed a moderated mediating model to investigate the direct effect of career calling on work fatigue, the mediating effect of role overload, and the moderating effect of COVID-19 event disruption in the above relationships. We administered an online questionnaire to 488 Chinese police officers who participated in frontline work to prevent and control the COVID-19 pandemic. The results showed a U-shaped curvilinear relationship of career calling with physical fatigue, mental fatigue, emotional fatigue, and role overload. Moreover, role overload partially mediated these curvilinear relationships. In addition, COVID-19 event disruption positively moderated the direct curvilinear effect of career calling on role overload, physical fatigue, and emotional fatigue, as well as the first stage of the mediating effect in the relationship between career calling and physical, mental, and emotional fatigue through role overload. Furthermore, the direct U-shaped curvilinear effects and the indirect effects were more significant when COVID-19 event disruption was high.

The Analysis Method of Changes in "Global-China" International Relations during the COVID-19 Event based on News Data

The outbreak of the COVID-19 event has been a major international concern since the first case was discovered in December 2019. After mid- to- late February 2020, the daily number of newly diagnosed cases abroad has increased rapidly, showing the characteristics of a pandemic disease. Under the deep impact of the COVID-19 event, the international relations are intricate and ever-changing. The instability and uncertainty of international relations have increased dramatically and have brought profound changes to the economy, security, and diplomacy. A comprehensive and timely analysis of "Global-China" international relations and its changing characteristics has important reference value for China's diplomatic development planning. Complex international relations can be split up into a series of event units. News data contains key information such as time, location, people, things, etc. It is the most direct and comprehensive source of information for constructing events. The GDELT ( Global Database of Events, Language, and Tone ) is a free and open news database which monitors news from print, broadcast, and online media in the world then analyzes the texts and extracts the key information such as people, location, organization, and event. From the perspective of "Global-China", this paper takes GDELT as the data source and uses global news data about the COVID-19 event from January to May 2020 to analyze the changes in international relations. First of all, the characteristics of international relations, such as intensity, similarity and polarity, are consistent with emotions. According to Plutchik's wheel of emotions, this paper provides a representation and calculation model of international relations to solve the problem of ambiguity in representation and the difficulty in calculation, using key variables including the number of events, the intensity of events, and the number of mentioned events. Then, the features of the changes in international relations are obviously displayed from the perspective of spatio-temporal visualization. Finally, this paper analyzes the causes of changes in international relations by important international events during the COVID-19 event. The results show that the analysis method can accurately reveal the development degree of the "Global-China" international relations during the COVID-19 event and find out the rules and causes of changes and has important application value. This paper can provide a new perspective for the exploration of international relations and a reference for the analysis of news data in the era of big data. And it shows the great potential and broad prospect of the research on international relations of big data. 2021, Science Press. All right reserved.

On being warm and friendly: The effect of socially responsible human resource management on employee fears of the threats of COVID-19

Purpose: This paper aims to investigate the influence of socially- responsible human resource management (SRHRM) on employee fears of external threats during the COVID-19 outbreak, based on social support and event system theories. COVID-19 caused sharp profit declines and bankruptcies of hotels, restaurants and travel agencies. In addition, employees faced threats to their health and job security. How to overcome employee anxieties and fears about the negative impacts of this crisis and promote psychological recovery is worthy of attention from researchers and practitioners. This research investigated the impacts of SRHRM on employee fears through organizational trust, with the COVID-19 pandemic playing a moderating role between SRHRM and employee fears. Design/methodology/approach: The hypotheses were tested through multiple linear regression analysis based on a survey of 408 employees in hospitality and tourism firms in China. Qualitative data were also gathered through interviews with selected managers. Findings: The results showed that SRHRM had a negative influence on employee fears of external threats by enhancing trust in their organizations. In addition, the strength of the COVID-19 pandemic positively moderated the effect of SRHRM on employee fears. When the pandemic strength was more robust, the negative effects of SRHRM on employee fears were more significant. Research limitations/implications: This research illustrated the contribution of SRHRM in overcoming employee fears of external threats in the context of COVID-19. It shed light on the organizational contribution of SRHRM to hospitality and tourism employee psychological recovery during the crisis. Originality/value: This research explored strategic HRM by examining the effects of SRHRM on employee fears in the midst of a severe crisis, specifically COVID-19. The moderation effect of event strength and mediation effect of organizational trust were tested. It is of great value for hospitality and tourism firms to foster employee psychological recovery during a crisis such as COVID-19. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

Assessment of PM2.5 Chemical Composition and Air Quality Monitoring: Implications of Air Pollutants Emissions from a Night Market in Kaohsiung City, Taiwan

There are around 300 night markets in Taiwan, and they have been drawing an increasing number of tourists in recent years. As a result, public awareness over air quality in the night markets has grown tremendously. In response to this, a specific night market in Kaohsiung City was chosen for this study in order to characterize the existing air quality in and around the night markets. In this present study, we employed an Industrial Source Complex Short-Term (ISCST3) air quality model for the simulation of PM2.5 diffusions. The model as a technique can simulate the pollutants emissions, diffusions, transportation, and pollution sources in specific areas and subsequently evaluate the influence between the source and the receiver. Therefore, we compared pollutants emissions data from several air quality monitoring stations with our sampling data of three different sampling sites in Kaohsiung City. The findings of this study showed that the average concentration of PM2.5 was in the range of 29-61 mu g m(-3) during opening hours of the night market, whereas the average concentration of PM2.5 range was between 22-38 mu g m(-3) before the night market opening hours. The concentration of metallic elements (ME) (Mg, Na, Cr, Mn, Fe, Cu, Al, Ba, Cd, Pb and Ca) was determined with the support of Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). During the night market opening hours, the result disclosed that the ME concentrations in PM2.5 was in an increasing order as follows: Na > Fe > Al > Ca. With respect to the concentration of carbonaceous species, our results showed that the highest total carbon (TC) concentration was found to be 6.52 mu g m(-3) during the downwind sampling interval. The highest elemental carbon (EC) and organic carbon (OC) concentration were found to be 6.53 mu g m(-3) and 2.70 mu g m(-3) of the PM2.5 concentration, respectively. This study's findings have significant consequences for Taiwan policymakers and urban planners, particularly those responsible for coordinating environmental protection and economic development in cities. Therefore, policy actions to abate urban air pollution can be attained on diverse governing echelons, resulting in synergistic effects such as a reduction in climate change impacts.

Growth Mindset and College Students' Learning Engagement During the COVID-19 Pandemic: A Serial Mediation Model.

Against the scourge of the COVID-19 pandemic, college students' learning engagement has become a key issue in universities and society. Guided by the theories of existential positive psychology and social perception, we explored the positive effect of a growth mindset on learning engagement during the COVID-19 pandemic. A total of 1,040 college students from universities in Henan Province of China effectively completed online questionnaires. The results showed that growth mindset was positively related to learning engagement and negatively associated with perceived COVID-19 event strength and perceived stress; perceived COVID-19 event strength was positively related to perceived stress, while perceived COVID-19 event strength and perceived stress were negatively associated with learning engagement. Growth mindset affected learning engagement through three indirect paths: the mediating role of perceived COVID-19 event strength, the mediating role of perceived stress, and the serial mediating role of both perceived COVID-19 event strength and perceived stress. The results indicated that the growth mindset could contribute to college students' learning engagement through the roles of perceived COVID-19 event strength and perceived stress during the COVID-19 pandemic. This study advances the understanding of the mechanism underlying the relationship between growth mindset and college students' learning engagement during the COVID-19 pandemic. Furthermore, the findings of the study have important implications for promoting college students' learning engagement during the pandemic.