This research examines the moderating or buffering effects of two social support variables—support from the work group and from the supervisor—on the relationships of role conflict and ambiguity to intrinsic job satisfaction, job involvement and job anxiety. Data were collected from a sample of 89 middle-lower managerial personnel in a large, heavy equipment manufacturing firm in the Midwest. The moderated regression technique was used in data analysis. Significant interactions were obtained between the role variables and both social support variables. The results were in the predicted direction for positive work outcomes (i.e. job satisfaction and involvement) and contrary to prediction for negative work outcome (i.e. job anxiety). Implications of the findings for future research, the management of stress and leadership behaviour are discussed. 相似文献
Manufacturing systems evolution is afunction in multiple external and internal factors. With today’s global awareness of environmental risks as well as the pressing needs to compete through efficiency, manufacturing systems are evolving into a new paradigm. This paper presents a system model for the new green manufacturing paradigm. The model captures various planning activities to migrate from a less green into a greener and more eco-efficient manufacturing. The various planning stages are accompanied by the required control metrics as well as various green tools in an open mixed architecture. The system model is demonstrated by an industrial case study. The proposed model is a comprehensive qualitative answer to the question of how to design and/or improve green manufacturing systems as well as a roadmap for future quantitative research to better evaluate this new paradigm. 相似文献
Titanium dioxide nanoparticles(TiO_2 NPs) are subjected to various transformation processes(chemical, physical and biological processes) in the environment, potentially affecting their bioavailability and toxic properties. However, the size variation of TiO_2 NPs during aging process and subsequent effects in mammalian cells are largely unknown. The aim of this study was to illustrate the adverse effects of TiO_2 NPs in different sizes(5, 15 and 100 nm) during aging process on human-hamster hybrid(A_L) cells. There was an aging-time dependent enhancement of average hydrodynamic size in TiO_2 NPs stock suspensions. The cytotoxicity of fresh TiO_2 NPs increased in a size-dependent manner; in contrast, their genotoxicity decreased with the increasing sizes of NPs. No significant toxicity difference was observed in cells exposed to either fresh or 60 day-aged TiO_2 NPs. Both Fresh and aged TiO_2 NPs efficiently induced mitochondrial dysfunction and activated Caspase-3/7 in a size-dependent manner.Using mitochondrial-DNA deficient(ρ~0) ALcells, we further discovered that mitochondrial dysfunction made significant contribution to the size-dependent toxicity induced by TiO_2 NPs during the aging process. Taken together, our data indicated that TiO_2 NPs could significantly induced the cytotoxicity and genotoxicity in an aging time-independent and size-dependent manner, which were triggered by mitochondrial dysfunction. Our study suggested the necessity to include size as an additional parameter for the cautious monitoring of TiO_2 NPs disposal before entering the environment. 相似文献
A series of new biochar-supported composite based on the combination of biochar and metallic nanoparticles(NPs)were produced through single-step pyrolysis of FeCl_3–Ti(OBu)_4 laden agar biomass under NH_3 environment.The physiochemical properties of composites were characterized thoroughly.It has found that heating temperature and N-doping through NH_3-ambiance pyrolysis significantly influence the visible-light sensitivity and bandgap energy of composites.The catalytic activities of composites were measured by degradation of Methylene Blue(MB)in the presence or absence of H_2O_2 and visible-light irradiation.Our best catalyst(N–TiO_2–Fe_3O_4-biochar)exhibits rapid and high MB removal competency(99.99%)via synergism of adsorption,photodegradation,and Fenton-like reaction.Continuous production of O_2U~-and UOH radicles performs MB degradation and mineralization,confirmed by scavenging experiments and degradation product analysis.The local trap state Ti~(3+),Fe_3O_4,and N-carbon of the catalyst acted as active sites.It has suggested that the Ti~(3+)and N-doped dense carbon layer improve charge separation and shuttle that prolonged photo-Fenton like reaction.Moreover,the catalyst is highly stable,collectible,and recyclable up to 5 cycles with high MB degradation efficiency.This work provides a new insight into the synthesis of highly visible-light sensitized biocharsupported photocatalyst through NH_3-ambiance pyrolysis of NPs-laden biomass. 相似文献
Environmental Chemistry Letters - Microalgae are photosynthetic cell factories of global interest for fuels, food, feed, bioproducts, carbon sequestration, waste mitigation, and environmental... 相似文献
Environmental Science and Pollution Research - Effective design of ultrafast new-generation photocatalysts is a challenging task that requires highly dedicated efforts. This research focused on the... 相似文献
China and India are the largest coal consumers and the most populated countries in the world. With industrial and population growth, the need for energy has increased, which has inevitably led to an increase in carbon dioxide (CO2) emissions because both countries depend on fossil fuel consumption. This paper investigates the impact of energy consumption, financial development (FD), gross domestic product (GDP), population, and renewable energy on CO2 emissions. The study applies the long short-term memory (LSTM) method, a novel machine learning (ML) approach, to examine which influencing driver has the greatest and smallest impact on CO2 emissions; correspondingly, this study builds a model for CO2 emission reduction. Data collected between 1990 and 2014 were analyzed, and the results indicated that energy consumption had the greatest effect and renewable energy had the smallest impact on CO2 emissions in both countries. Subsequently, we increased the renewable energy coefficient by one and decreased the energy consumption coefficient by one while keeping all other factors constant, and the results predicted with the LSTM model confirmed the significant reduction in CO2 emissions. Finally, this study forecasted a CO2 emission trend, with a slowdown predicted in China by 2022; however, CO2 emission’s reduction is not possible in India until 2023. These results suggest that shifting from nonrenewable to renewable sources and lowering coal consumption can reduce CO2 emissions without harming economic development.
Environmental Science and Pollution Research - This current study review provides a brief review of a natural bee product known as propolis and its relevance toward combating SARS-CoV viruses.... 相似文献