• 제목/요약/키워드: environmentally sustainable

검색결과 362건 처리시간 0.023초

고분자 전해질 막 연료 전지용 1차원 나노 구조 촉매의 연구 현황 (Current Status of One-Dimensional Nanostructured Catalysts for Polymer Electrolyte Membrane Fuel Cell)

  • 전기웅;정연식
    • 세라미스트
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    • 제21권4호
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    • pp.331-348
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    • 2018
  • With the expectation to overcome the problem of increasing energy consumption, polymer electrolyte membrane fuel cells are getting more attention as a promising environmentally friendly and sustainable next-generation energy conversion system. In spite of the rapid improvement of polymer electrolyte membrane fuel cells(PEMFCs), there are several critical issues still need to be resolved for practical commercialization. Out of the many issues, the main hurdle comes from oxygen reduction reaction(ORR), thus development of efficient ORR electrocatalysts is the main key for enhancing PEMFC performance. Among various catalysts, 1D nanostructured catalyst is a promising candidate because it holds many advantages that come from nanostructuring while supplementing the disadvantages of other nanostructures such as nanoparticles(0D) or gyroids(3D). This review focused on diverse 1D nanostructures and talks about their advantages as catalyst for ORR. Different 1D nanostructures will be introduced while applying the structures to different materials system showing the prospects of 1D nanostructures for improving PEMFC.

비점오염원관리를 위한 레인가든에서 식물과 토양의 영양물질과 중금속 농도변화 (Changes in Concentrations of Nutrients and Heavy Metals of Plants and Soils in Rain Garden Systems used for Non-point Source Pollution Management)

  • 김창수;성기준
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제17권4호
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    • pp.27-35
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    • 2012
  • Recently, there has been increasing interest in the use of rain garden systems as environmentally friendly ecological infrastructures for controlling stormwater runoff and managing non-point source pollution and information for the contamination of soil and plants can be essential for sustainable rain garden management. In this study, four rain garden mesocosms, namely single species planting with Rhododendron lateritium, single species planting with Zoysia japonica, mixed planting with R. lateritium and Z. japonica, and control without plants, were tested to investigate the change in concentrations of nutrients (N and P) and heavy metals (Cd, Cu, Pb, and Ni) in the soil and plants used in the rain garden system. The presence of plants resulted in greater nutrient retention in soil and lower potential leaching from the system. All systems showed an increase in the heavy metal concentrations in soil. The concentrations of most heavy metals were found to be higher in the herbaceous plants (Z. japonica) than in the shrubs (R. lateritium). The belowground part (root) had higher heavy metal concentrations than the aboveground part (leaf) but also showed a potential increase in leaves, and hence, careful plant management should be considered during rain garden operation.

Improving compressive strength of low calcium fly ash geopolymer concrete with alccofine

  • Jindal, Bharat Bhushan;Singhal, Dhirendra;Sharma, Sanjay K.;Ashish, Deepankar K.;Parveen, Parveen
    • Advances in concrete construction
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    • 제5권1호
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    • pp.17-29
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    • 2017
  • Geopolymer concrete is environmentally friendly and could be considered as a construction material to promote the sustainable development. In this paper fly ash based geopolymer concretes with different percentages of alccofine were made by mixing sodium hydroxide and sodium silicate as an alkaline activator and cured at ambient as well as heat environment in an electric oven at $90^{\circ}C$. Effects of various parameters such as the percentage of alccofine, curing temperature, a period of curing, fly ash content, was studied on compressive strength as well as workability of geopolymer concrete. The study concludes that the presence of alccofine improves the properties of geopolymer concrete during a fresh and hardened state of concrete. Geopolymer concrete in the presence of alccofine can be used for the general purpose of concrete as required compressive strength can be achieved even at ambient temperature. The 28 days compressive strength of 73 MPa, when cured at 90-degree Celsius, confirmed that it is also very suitable for precast concrete components.

Current Status and Future Prospects of White Root Rot Management in Pear Orchards: A Review

  • Sawant, Shailesh S.;Choi, Eu Ddeum;Song, Janghoon;Seo, Ho-Jin
    • 식물병연구
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    • 제27권3호
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    • pp.91-98
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    • 2021
  • The current social demand for organic, sustainable, and eco-friendly approaches for farming, while ensuring the health and productivity of crops is increasing rapidly. Biocontrol agents are applied to crops to ensure biological control of plant pathogens. Research on the biological control of white root rot disease caused by a soil-borne pathogen, Rosellinia necatrix, is limited in pears compared to that in apple and avocado. This pathogenic fungus has an extensive host range, and symptoms of this disease include rotting of roots, yellowing and falling of leaves, wilting, and finally tree death. The severity of the disease caused by R. necatrix, makes it the most harmful fungal pathogen infecting the economical fruit tree species, such as pears, and is one of the main limiting factors in pear farming, with devastating effects on plant health and yield. In addition to agronomic and cultural practices, growers use chemical treatments to control the disease. However, rising public concern about environmental pollution and harmful effects of chemicals in humans and animals has facilitated the search for novel and environmentally friendly disease control methods. This review will briefly summarize the current status of biocontrol agents, ecofriendly methods, and possible approaches to control disease in pear orchards.

Comparison of Bioethanol Production by Candida molischiana and Saccharomyces cerevisiae from Glucose, Cellobiose, and Cellulose

  • Zheng, Jianning;Negi, Abhishek;Khomlaem, Chanin;Kim, Beom Soo
    • Journal of Microbiology and Biotechnology
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    • 제29권6호
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    • pp.905-912
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    • 2019
  • Bioethanol has attracted much attention in recent decades as a sustainable and environmentally friendly alternative energy source. In this study, we compared the production of bioethanol by Candida molischiana and Saccharomyces cerevisiae at different initial concentrations of cellobiose and glucose. The results showed that C. molischiana can utilize both glucose and cellobiose, whereas S. cerevisiae can only utilize glucose. The ethanol yields were 43-51% from different initial concentrations of carbon source. In addition, different concentrations of microcrystalline cellulose (Avicel) were directly converted to ethanol by a combination of Trichoderma reesei and two yeasts. Cellulose was first hydrolyzed by a fully enzymatic saccharification process using T. reesei cellulases, and the reducing sugars and glucose produced during the process were further used as carbon source for bioethanol production by C. molischiana or S. cerevisiae. Sequential culture of T. reesei and two yeasts revealed that C. molischiana was more efficient for bioconversion of sugars to ethanol than S. cerevisiae. When 20 g/l Avicel was used as a carbon source, the maximum reducing sugar, glucose, and ethanol yields were 42%, 26%, and 20%, respectively. The maximum concentrations of reducing sugar, glucose, and ethanol were 10.9, 8.57, and 5.95 g/l, respectively, at 120 h by the combination of T. reesei and C. molischiana from 50 g/l Avicel.

The Influence of Environmental Concern and Green Fashion Advertisements on Consumer Behavior: Chinese vs. Korean

  • Shi, Hang;Cui, Yu Hua
    • 패션비즈니스
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    • 제22권6호
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    • pp.25-38
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    • 2018
  • Recently, issues on the environment, which have become key bottlenecks relative to sustainable economic development, have generated common concern. However, relatively scant research has been devoted to consideration of relations between consumers' environmental concern, green fashion advertisement value, and green consumption. In this study, using structural equation modeling (SEM), effects of environmental concern, perceived green fashion advertisement value, and attitude towards green fashion advertisements, on ecological purchases and their interrelationships are investigated. A model is constructed to link aforementioned constructs. Data, was collected through a questionnaire-based online survey (www.sojump.com) of 260 Korean consumers and 260 Chinese consumers. Findings suggest that environmental concern can improve their perception of green advertisement value. One of the findings showed strong positive relationship among green advertisement value, positive attitude, and purchase intention towards green fashion advertisement, while environmental concern negatively influenced their attitude towards green fashion advertisements. It suggests that if companies adopt green advertising strategies, environmentally-conscious consumers are willing to pay more, to purchase green fashion goods in to satisfy their needs. We should put more effort in educating consumers about environmental issues, to raise the level of environmental awareness and satisfy their concerns relative to green fashion goods. Conversely, there is significant positive relationship with the moderating effect of consumers' nationality in all paths, so results above would make significant contributions to green literature, and would also contribute to advertisement strategy implications as well. Especially fashion marketers, an use accurate and fair environmental claims in their advertisements to increase sale and profits.

내부 그린SCM실행이 외부 그린SCM실행과 국내 제조기업의 성과에 미치는 영향에 관한 연구 (A Study on the Effect of Internal Green SCM Implementation on External Green SCM Implementation and Performance of Korean Manufacturing Firms)

  • 윤석규;이문수;장익근
    • 대한설비관리학회지
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    • 제23권4호
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    • pp.5-19
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    • 2018
  • Recently, utilizing the supply chain among companies, major companies support their sub-vendors to establish an environmental management system and transfer the clean production technology(know-how) to them for strengthening of environmental competitiveness. Thus, Green Supply Chain Management(GSCM) became a key successful factor for companies to be environmentally sustainable. This research endeavors to identify the relationship among the inside and outside GSCM implementation activities of Korean manufacturing companies and their financial, operational and environmental performances. Based on a the review of previous research findings, twenty one hypotheses are developed and examined. Total 251 valid responses from 1,634 survey responses are identified and the structural equation models(SEM) are developed and analysed for examining our hypotheses. The result shows that inside GSCM has a positive effect on outside GSCM. Also, it reveals that companies' performances are more positively affected by inside GSCM than by outside GSCM.

Evaluation of Injection capabilities of a biopolymer-based grout material

  • Lee, Minhyeong;Im, Jooyoung;Chang, Ilhan;Cho, Gye-Chun
    • Geomechanics and Engineering
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    • 제25권1호
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    • pp.31-40
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    • 2021
  • Injection grouting is one of the most common ground improvement practice to increase the strength and reduce the hydraulic conductivity of soils. Owing to the environmental concerns of conventional grout materials, such as cement-based or silicate-based materials, bio-inspired biogeotechnical approaches are considered to be new sustainable and environmentally friendly ground improvement methods. Biopolymers, which are excretory products from living organisms, have been shown to significantly reduce the hydraulic conductivity via pore-clogging and increase the strength of soils. To study the practical application of biopolymers for seepage and ground water control, in this study, we explored the injection capabilities of biopolymer-based grout materials in both linear aperture and particulate media (i.e., sand and glassbeads) considering different injection pressures, biopolymer concentrations, and flow channel geometries. The hydraulic conductivity control of a biopolymer-based grout material was evaluated after injection into sandy soil under confined boundary conditions. The results showed that the performance of xanthan gum injection was mainly affected by the injection pressure and pore geometry (e.g., porosity) inside the soil. Additionally, with an increase in the xanthan gum concentration, the injection efficiency diminished while the hydraulic conductivity reduction efficiency enhanced significantly. The results of this study provide the potential capabilities of injection grouting to be performed with biopolymer-based materials for field application.

Hydrogen production in the light of sustainability: A comparative study on the hydrogen production technologies using the sustainability index assessment method

  • Norouzi, Nima
    • Nuclear Engineering and Technology
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    • 제54권4호
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    • pp.1288-1294
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    • 2022
  • Hydrogen as an environmentally friendly energy carrier has received special attention to solving uncertainty about the presence of renewable energy and its dependence on time and weather conditions. This material can be prepared from different sources and in various ways. In previous studies, fossil fuels have been used in hydrogen production, but due to several limitations, especially the limitation of the access to this material in the not-too-distant future and the great problem of greenhouse gas emissions during hydrogen production methods. New methods based on renewable and green energy sources as energy drivers of hydrogen production have been considered. In these methods, water or biomass materials are used as the raw material for hydrogen production. In this article, after a brief review of different hydrogen production methods concerning the required raw material, these methods are examined and ranked from different aspects of economic, social, environmental, and energy and exergy analysis sustainability. In the following, the current position of hydrogen production is discussed. Finally, according to the introduced methods, their advantages, and disadvantages, solar electrolysis as a method of hydrogen production on a small scale and hydrogen production by thermochemical method on a large scale are introduced as the preferred methods.

Preference for Green Packaging in Consumer Product Choices: Empirical Evidence from Gen Z Consumers in Vietnam

  • Lan, NGUYEN;Trang Minh, NGUYEN;Quyen, TRINH;Nhu Anh, DAO
    • The Journal of Asian Finance, Economics and Business
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    • 제10권2호
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    • pp.281-300
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    • 2023
  • Recently, the call for better accountability and social responsibility from corporations has been regularly voiced, both in the academic literature and in public discussions. This poses a challenge to the existing literature in understanding consumption behaviors to direct them toward sustainable development. This study investigates the purchase intention of Gen Z consumers in Vietnam with green packaging products. Data were collected from 914 respondents by online questionnaire and then analyzed using OLS. The results suggest the significant influence of customers' income and packaging in driving customers' intention to use environmentally-friendly products. Specifically, consumers in a higher income class participate more actively in green purchases. However, problems associated with inadequate packaging are also illustrated, resulting in the poor perception of green messages and poor practice of ecological actions. Besides, subjective norms and green trust are found to be adversely related to green consumer intention. In addition, gender disparity in green behavior is reported, where female consumers show a higher tendency to ecological consumption than their male counterparts. Other demographic factors are also included in the model as control variables, which are age, education, price, environmental literacy, environmental concern, and psychological awareness, but they do not have a significant impact on green purchase intention.