Suchergebnisse

In the wake of increasing challenges of high prices of oil and gas and uncertainties about political stability in many oil and gas producing countries, coal becomes more and more important in the coming years for its vast reserves and wide distribution all over the world. The technology of Underground Coal Gasification (UCG), converting in-situ, unmined coal into combustible gases, has continued to attract worldwide interest because of its ability to exploit coal which is otherwise unminable by conventional mining techniques due to deep deposit depths, thin seam thickness or low quality, in an economical, safe and environmentally friendly manner. Ground subsidence seems to be an inevitable consequence of underground cavities formed by a commercial-scale UCG project. Unlike other mining methods (longwall mining, room-and-pillar mining, etc.), the rocks and coal in the vicinity of a UCG reactor are subjected to high temperatures which may be in excess of 1000°C. Thus, the purpose of this thesis was to predict UCG-induced ground subsidence by application of a thermo-mechanical rock failure criterion which involves high-temperature influences on rocks. An extensive literature review on sedimentary rocks and a suite of laboratory experiments on claystone after thermal treatment have been conducted to study temperature-dependent physical, mechanical and thermal properties, especially rock strength. These research efforts indicate that rock strength changes with temperature, and the varying characteristics can be generally categorized into three types. Based on this categorization, the thermo-mechanical Hoek-Brown (TMHB) and Mohr-Coulomb (TMMC) rock failure criteria were developed. The corresponding constitutive relations combined with the TMHB criterion were also developed by means of the incremental theory of thermo-plasticity. In addition, using the closest point projection method (CPPM), a subroutine of this constitutive model was implemented into Abaqus/Standard. Furthermore, potential ground subsidence in a ...

The potential contribution of nutritionally fortified foods to the improvement of public health has been recognized internationally; however, the extent of people's preferences for functional foods and the influence of information intervention on consumers' acceptance and selection of nutritious foods have not been comprehensively studied in China. The main purposes of this study are to assess Chinese consumers' perceptions towards nutritionally fortified eggs and to explore the ways in which information about the health benefits and the international market status quo of functional eggs impacts Chinese consumers' preferences and their willingness to pay (WTP) for nutritional fortification. Discrete choice experiments were used to elicit the preferences of 740 egg consumers from four cities in China, and a mixed logit model subsequently utilized to interpret the results. It was found that the provision of comprehensive information regarding the health benefits of trace elements and unsaturated fatty acids, as well as insight into the current market status quo, significantly improved participants' preferences and their WTP for functional eggs. Furthermore, the heterogeneous effects of demographic and sociocultural factors on consumers' treatment of this information were explored. It was found that the study participants with children and those with prior purchase experience exhibited a relatively stronger response to the information, while those who had expressed trust in the human health benefits of the nutritional content of functional eggs were not as sensitive as expected to the additional information. Therefore, if the government and enterprises design appropriate information treatment and nudging methods according to the current consumption characteristics of nutritionally fortified eggs, this will help to improve consumers' purchase confidence in the health efficacy of functional food and play a positive role in promoting people's healthy food consumption.

Realistic environmental problems drive the growth of pro-environment behavior research, among which the most important progress is about the theoretical innovation and development of pro-environmental behavior. Thus, the main purpose of this paper was to review the literature and help researchers to understand the theoretical progress of pro-environmental behavior. This study systematically analyzed 1806 papers published in SCI-EXPANDED and SSCI databases. It presented the research overview of pro-environmental behavior in terms of status of literature publication, research hotspots and topics. On this basis, this paper further focused on key theoretical papers and summarized three paths of theoretical progress for pro-environmental behavior: theoretical development, theoretical exploration and theoretical integration. Along the theoretical development path, studies mainly apply theories of psychology, sociology and economics to analyze and explain the formation and consequences of pro-environmental behavior. In terms of theoretical exploration, existing studies propose and develop value-belief-norm theory, behavioral theories related to contexts and pro-environmental behavior decision models. Theoretical integration is the direction of future research, such as the combination of rationality and sensibility, and the combination of external and internal causes. Therefore, this paper summarized the theoretical progress of pro-environmental behavior and proposed future research directions, which contribute to its theoretical development.

AbstractThe need for organizations to safeguard and advance environmental sustainability has recently become imperative due to mounting pressures from various stakeholder groups. However, a significant research gap remains regarding how these pressures influence enterprises' green practices and performance. The aim of this study is to examine the impact of green market pressure exerted by customers and competitors on firm performance, taking into account the multiple mediating effects of green value co‐creation and green dynamic capability. Questionnaire survey data collected from 274 high‐tech manufacturing companies in the Yangtze River Delta of China were used to test the proposed relationships. By testing the mediation effects based on stakeholder theory and dynamic capability view, the results show that green market pressure positively affects firm performance, while both green value co‐creation and green dynamic capability play as an individual mediator between green market pressure and firm performance. Moreover, green value co‐creation and green dynamic capability sequentially mediate the link between green market pressure and firm performance. These findings provide valuable suggestions for improving firm performance under the background of environmental protection.

AbstractConsumers' product‐disposal behaviors impact the environment, businesses, society, and consumer well‐being. This research explores if and how consumers' disposal behaviors are influenced by sentiments of nostalgia. Four experimental studies are conducted, two on student samples and two on general population, to test our hypotheses. Study 1 shows that compared with collective nostalgia, personal nostalgia elicits higher intention to keep and reuse products. In contrast, collective nostalgia elicits higher intention to donate and recycle products. Both personal nostalgia and collective nostalgia reduce intention to throw away. Study 2 further corroborates the negative impact of personal nostalgia and collective nostalgia on throw away intention. Study 3 finds that the positive effect of personal nostalgia on keep and reuse intention is mediated by self‐continuity. Finally, study 4 demonstrates that collective efficacy mediates the positive effect of collective nostalgia on donate and recycle intention. This study has theoretical contributions and practical implications for scholars and policy makers.

We integrated certainty effect and noninteractive social influence into impulse buying, and explored the relationships between impulse buying tendency and intention in regard to the impacts of certainty effect and social influence. We selected 2 certainty effects (1-phase and 2-phase
discounts) and 3 social influences (number, proximity, and strength) that stimulate consumers' impulse buying intention for a unique product. The participants were 416 students at 5 universities in northern Taiwan. Results of structural equation modeling indicated that impulse buying tendency
positively influenced impulse buying intention in terms of certainty effects and social influences; there was a positive relationship between certainty effects and social influences in impulse buying intention; the students preferred 2-phase to 1-phase discounts; and, in descending order,
the social influences of strength, number, and proximity impacted impulse buying intention. We concluded that marketers can use certainty effects and noninteractive social influences to stimulate consumers' buying intention.

The formation kinetics of browning products (BPs) derived from the self-degradation of L-ascorbic acid (AA) and the reaction between AA and glycine (Gly) were investigated at pH 6.8 and various other parameters, such as temperature, time, and molar concentration ratio of AA/Gly. The temperature ranged from 110 to 150°C, the time ranged from 10 to 240 min, and the molar concentration ratios of AA to Gly were 4:1, 2:1, 1:1, 1:2, and 1:4. The results suggested that the formation rate of BPs was promoted by increasing the temperature, prolonging the time, and augmenting the molar ratio of AA. Based on the assumption of a kinetic model and a possible reaction pathway, the formation rate of BPs followed a pseudo-first order, and the rate was primarily dependent on the consumption of AA. The formation activation energies (Ea) for the BPs were 60.76 and 70.16 kJ/mol with AA/Gly ratios of 4:1 and 1:4, respectively.