scholarly journals A Heterodimeric Reduced-Ferredoxin-Dependent Methylenetetrahydrofolate Reductase from Syngas-Fermenting Clostridium ljungdahlii

2021 ◽  
Author(s):  
Jihong Yi ◽  
Haiyan Huang ◽  
Jiyu Liang ◽  
Rufei Wang ◽  
Ziyong Liu ◽  
...  
Keyword(s):  
Methylenetetrahydrofolate Reductase ◽  
Environmental Benefits ◽  
Steel Mill ◽  
Domestic Waste ◽  
Content Type ◽  
Waste Gas ◽  
Clostridium Ljungdahlii ◽  
Main Component ◽  
Mill Waste

Syngas, a mixture of CO, CO 2 , and H 2 , is the main component of steel mill waste gas and also can be generated by the gasification of biomass and urban domestic waste. Its fermentation to biofuels and biocommodities has attracted attention due to the economic and environmental benefits of this process. Clostridium ljungdahlii is one of the superior acetogens used in the technology.

scholarly journals Lactose-Inducible System for Metabolic Engineering of Clostridium ljungdahlii

2014 ◽  
Vol 80 (8) ◽  
pp. 2410-2416 ◽  
Author(s):  
Areen Banerjee ◽  
Ching Leang ◽  
Toshiyuki Ueki ◽  
Kelly P. Nevin ◽  
Derek R. Lovley
Keyword(s):  
Ethanol Production ◽  
Genetic Manipulation ◽  
Electron Flow ◽  
Model Organism ◽  
Inducible Expression ◽  
Carbon Flow ◽  
Wild Type ◽  
Content Type ◽  
Microbial Electrosynthesis ◽  
Clostridium Ljungdahlii

ABSTRACTThe development of tools for genetic manipulation ofClostridium ljungdahliihas increased its attractiveness as a chassis for autotrophic production of organic commodities and biofuels from syngas and microbial electrosynthesis and established it as a model organism for the study of the basic physiology of acetogenesis. In an attempt to expand the genetic toolbox forC. ljungdahlii, the possibility of adapting a lactose-inducible system for gene expression, previously reported forClostridium perfringens, was investigated. The plasmid pAH2, originally developed forC. perfringenswith agusAreporter gene, functioned as an effective lactose-inducible system inC. ljungdahlii. Lactose induction ofC. ljungdahliicontaining pB1, in which the gene for the aldehyde/alcohol dehydrogenase AdhE1 was downstream of the lactose-inducible promoter, increased expression ofadhE130-fold over the wild-type level, increasing ethanol production 1.5-fold, with a corresponding decrease in acetate production. Lactose-inducible expression ofadhE1in a strain in whichadhE1and theadhE1homologadhE2had been deleted from the chromosome restored ethanol production to levels comparable to those in the wild-type strain. Inducing expression ofadhE2similarly failed to restore ethanol production, suggesting thatadhE1is the homolog responsible for ethanol production. Lactose-inducible expression of the four heterologous genes necessary to convert acetyl coenzyme A (acetyl-CoA) to acetone diverted ca. 60% of carbon flow to acetone production during growth on fructose, and 25% of carbon flow went to acetone when carbon monoxide was the electron donor. These studies demonstrate that the lactose-inducible system described here will be useful for redirecting carbon and electron flow for the biosynthesis of products more valuable than acetate. Furthermore, this tool should aid in optimizing microbial electrosynthesis and for basic studies on the physiology of acetogenesis.

Tribological behaviors of some novel dimercaptothiadiazole derivatives containing hydroxyl as multifunctional lubricant additives in biodegradable lithium grease

2014 ◽  
Vol 66 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Huan Chen ◽  
Junhui Jiang ◽  
Tianhui Ren ◽  
Lei Zheng ◽  
Yidong Zhao
Keyword(s):  
Lubricant Additives ◽  
Short Chain ◽  
Lithium Grease ◽  
Edge Structure ◽  
Content Type ◽  
Organic Sulfide ◽  
Ferrous Sulfide ◽  
Heterocyclic Derivatives ◽  
Main Component ◽  
Thermal Films

Purpose – In order to meet the requests of exploring environmental-friendly and multifunctional lubricant additives, some novel dimercaptothiadiazole derivatives containing hydroxyl are prepared and used as antiwear (AW) and extreme-pressure (EP) additives in biodegradable lithium grease. The paper aims to discuss these issues. Design/methodology/approach – The tribological performances of the grease samples containing these derivatives are evaluated by using a four-ball tester. X-ray absorption near edge structure (XANES) spectroscopy is used to analyze the chemistry of tribofilms under AW/EP regime, and thermal films are also considered for comparison. Findings – The tribological tests show that these derivatives are all effective in reducing wear, especially at lower additive concentrations, but they are basically failed in reducing friction. They are also helpful in improving the EP characteristic of the base grease. The thermal films generated by these derivatives are composed of adsorbed organic sulfide and ferrous sulfate, though for short-chain derivatives, organic sulfide is the only component at 5.0 wt.%. Ferrous sulfide is the main component of the tribofilms formed by these derivatives at various additive concentrations. But for short-chain derivatives, these tribofilms consist of ferrous sulfide and ferrous disulfide at 5.0 wt.%, and the appearance of disulfide suggests that the interfacial temperature between the upper ball and three lower balls under these conditions is considerably low. The EP films generated by short-chain derivatives are all composed of organic sulfide and ferrous sulfide, while for long-chain derivatives, ferrous sulfide is the main component. Originality/value – These low-toxic and oil-soluble dimercaptothiadiazole derivatives are effective in improving the tribological characteristic of the biodegradable lithium grease, and these heterocyclic derivatives may be good substitutes for some harmful traditional additives.

Residents’ attitudes toward tourism development at Al-Juhfa, Saudi Arabia

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ali Ahmad Algassim ◽  
Akhmad Saufi ◽  
Diswandi Diswandi ◽  
Noel Scott
Keyword(s):  
Saudi Arabia ◽  
Social Exchange ◽  
Social Exchange Theory ◽  
Tourism Development ◽  
Structured Interview ◽  
Environmental Benefits ◽  
Structured Interviews ◽  
Content Type ◽  
Negative Impacts ◽  
Residents Attitudes

Purpose Al-Juhfa is a small village located near Rabigh City, between Makkah and Madinah, Saudi Arabia, with significant archaeological and religious resources. The purpose of this paper is to examine residents’ attitudes toward tourism development at Al-Juhfa. Design/methodology/approach The qualitative study uses purposive interviewing to recruit informants. Data was collected using semi-structured interview and open-ended questions. Eight semi-structured interviews were made and a list of open-ended questions was distributed to 134 informants. All data were analysed and no new codes were found after the answer of the first 49 informants analysed. Findings The results show that residents’ attitudes toward tourism development in general were positive with residents expecting to receive economic, social and environmental benefits. Residents were aware of potential positive and negative impacts of tourism development and appeared to balance these in developing their attitudes. Tourism was seen to empower residents and the religiosity of the community influenced their perception of tourism development. Originality/value This study contributes to the literature by supporting the use of social exchange theory in this context and by recommending the inclusion of religiosity in further studies.

scholarly journals Comparison of Conventional and Novel Pre-treatment Methods for Bioethanol Production from Fruit and Vegetable Wastes

2020 ◽  
Vol 33 (4) ◽  
pp. 471-483
Author(s):  
Tugba Keskin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
The Other ◽  
Yeast Fermentation ◽  
Bioethanol Production ◽  
Fruit And Vegetable ◽  
Bacterial Fermentation ◽  
Waste Gas ◽  
Clostridium Ljungdahlii ◽  
Vegetable Wastes ◽  
Pre Treatment

In this study, novel and conventional techniques for the production of bioethanol from fruit and vegetable wastes (FVWs) by yeast and bacterial fermentation were investigated experimentally. Different pretreatment techniques (acid, heat, acid/heat, and microwave) for yeast fermentation were compared. Maximum ethanol concentrations of 11.7 and 11.8 g L–1 were observed from acid/heat and microwave pretreatment, respectively, by using Saccharomyces cerevisiae. On the other hand, biochar production from FVWs and syngas fermentation from the waste gas of this process were integrated. From waste gas with 12 % CO content, 5.5 g L–1 and 2.5 g L–1 ethanol production was observed by using anaerobic mixed culture and Clostridium ljungdahlii, respectively. The overall results emphasize the potential of bioethanol production from FVWs by economically feasible and environmentally friendly methods.

scholarly journals Prospects of applying 3-D printing to economics of remote communities

2018 ◽  
Vol 12 (4) ◽  
pp. 488-509 ◽  
Author(s):  
Svetlana Obydenkova ◽  
Nicholas C. Anzalone ◽  
Joshua M. Pearce
Keyword(s):  
Open Source ◽  
Case Studies ◽  
Raw Materials ◽  
Economic Feasibility ◽  
Environmental Benefits ◽  
Remote Communities ◽  
Fused Filament Fabrication ◽  
Content Type ◽  
Climate Conditions ◽  
Reindeer Herder

Purpose Isolated communities face a variety of inconveniences including severe remoteness, poor roads and extreme climate conditions, resulting in the lack of security of supply chains and exorbitant prices for cargo delivery. This paper aims to investigate the present advantages and prospects of applying 3-D printing to improve economics and everyday life of remote communities, reindeer herder case taken as an example. Design/methodology/approach This study covers the use of a low-cost open-source 3-D printer (RepRap) capable of fused filament fabrication to reduce operating costs for nomadic reindeer herder groups. Three case studies are provided for reindeer-specific applications to probe economic and technical viability of the technology, namely, ear-tags, electric fence components and lasso accessories. Findings 3-D printed objects feature technical characteristics similar to those of analogues available on the market while reducing the price by 63 per cent. Distributed 3-D printing reduces the cost of raw materials by 68 per cent and shipping costs by 50 because of lower trip frequency. If all reindeer herders globally were to adopt distributed manufacturing of the three aforementioned sample items only, their annual savings from such solution would amount to US$2m. The paper discovers other economic, entrepreneurial, technical and environmental opportunities offered by 3-D printing put to service the needs of remote communities. Research limitations As the paper is the first-ever study of 3-D printing potential applied to the reindeer husbandry case, it is based on a more thorough analysis of the techno-economic feasibility of the technology, while cultural and entrepreneurial factors have been discussed as preconditions only. Practical implications The paper might serve as a valuable source of information for entrepreneurs, as well as for students and academics for further case studies in this area. Originality/value In remote conditions, 3-D printing offers a more sustainable way of good manufacturing. Numerous open source designs already available for specialists, financial effectiveness, environmental benefits and vast opportunities for entrepreneurs are among the most promising advantages of the technology.

Urban afforestation and its ecosystem balance contribution: a bibliometric review

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Patrik Gustavo Wiesel ◽  
Elias Dresch ◽  
Eduardo Rodrigo Ramos de Santana ◽  
Eduardo Alcayaga Loboestan
Keyword(s):  
Bibliometric Analysis ◽  
Well Being ◽  
Urban Trees ◽  
Environmental Benefits ◽  
Urban Centers ◽  
Content Type ◽  
Heat Islands ◽  
Ecological Relationships ◽  
Bibliometric Review ◽  
The City

PurposeUrbanization is characterized mainly by changes in land use and conversion of natural areas into built environments, as well as by a series of impacts, such as loss of biodiversity, which interfere with the proper functioning of ecological networks.Design/methodology/approachThus, the authors apply a bibliometric analysis using the term “Urban Trees” in the “Web of Science” database, between 2009 and 2019, as a keyword to include all urban green structures and identify the main aspects of urban ecological relationships. They found 8,367 published articles.FindingsThis review identified the main countries and research institutions that operate in urban afforestation. In general, developing countries seek to understand the environmental benefits that urban afforestation can provide, demonstrating the importance of maintaining existing green areas in urban centers to promote the balance of the ecosystem. It depends directly on the flow of ecosystem services provided by green infrastructures in the city, contributing significantly to carbon sequestration, retention of particulate matter, mitigation of heat islands and reduction of surface runoff, directly favoring the health and well-being of the population. The authors conclude that the actions currently implemented in urban afforestation, especially to increase the richness and abundance of species, will be decisive for the future of urban centers and the construction of more sustainable and egalitarian cities.Originality/valueThis work sought to develop a bibliographic research based on information obtained by bibliometric analysis that has the ability to identify trends and volumes of scientific production in a given area of knowledge.

Printability of bio-composite sheets made from paper mill and cardboard mill waste sludge

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hüseyin Yüce ◽  
Garip Genç ◽  
Sinan Sönmez ◽  
Öznur Özden ◽  
Ahmet Akgül ◽  
...  
Keyword(s):  
Design Methodology ◽  
Screen Printing ◽  
Polyester Resin ◽  
Composite Plates ◽  
Paper Mill ◽  
Content Type ◽  
Waste Sludge ◽  
Water Solvent ◽  
Paper Mill Waste ◽  
Mill Waste

Purpose The purpose of this study is to reveal the usability of waste paper sludge on the production of composite materials and the printability of their surfaces were investigated. Design/methodology/approach First, composite plates were produced by using dried and milled waste sludge together with polyester resin and epoxy. Screen printing using water, solvent and UV-based inks were carried out. Findings It was determined that UV and solvent-based inks in both resin groups were permanently attached to the surface of composite plates produced using paper mill waste sludge, while it was found that the adhesion was not achieved sufficiently in cardboard factory waste sludge. Originality/value The unique aspect of this study is obtained the composite plates from paper mill and cardboard mill waste sludge and improved the printability of them.

Deterrents to the adoption of green walls: a hybrid fuzzy-based approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sanaz Tabatabaee ◽  
Mojtaba Ashour ◽  
Saeed Reza Mohandes ◽  
Haleh Sadeghi ◽  
Amir Mahdiyar ◽  
...  
Keyword(s):  
Architectural Design ◽  
Environmental Benefits ◽  
Local Context ◽  
Maintenance Cost ◽  
Analytic Hierarchy ◽  
Content Type ◽  
Fuzzy Delphi ◽  
Wide Range ◽  
Green Walls ◽  
Hierarchy Process

PurposeGreen walls (GWs), comprising living walls and green facades, have been touted as environmentally friendly products in architectural design. GWs can be viable in every aspect of sustainability; they provide residents of buildings with a wide range of economic, social and environmental benefits. Despite this, the adoption rate of GW is still in its infancy stage, and the existing literature concerning the hindrances inhibiting GW adoption is very limited. To address these gaps, the aim of this paper is to identify and prioritize the hindrances to GW adoption in Hong Kong.Design/methodology/approachAfter identifying 17 hindrances through an in-depth review of literature, the fuzzy Delphi method (FDM) is employed to refine the hindrances based on the local context with the help of 21 qualified experts in the field. Subsequently, Fuzzy Parsimonious Analytic Hierarchy Process (FPAHP) is exploited as a recently developed technique to prioritize the identified hindrances.FindingsResults reveal that the most significant hindrances to the adoption of GW are maintenance cost, high installation cost, difficulties in maintenance, sophisticated implementation and inducement to fire. Findings call for scholars to address ways to improve GW installation practices and methods in order to eradicate the hindrances and provide lessons for policymakers, assisting them in facilitating the larger-scale adoption of GW.Originality/valueConsidering the dearth of studies on hindrances to the adoption of GWs, this paper provides a comprehensive outlook of the issue, providing knowledge that can be used as a building block for future scholars within the field. It also provides valuable insights for stakeholders within the construction industry about the hindrances to the adoption of GWs which could direct their efforts toward better implementation of it.

Antecedents of hedonism affecting memorable tourism experience (MTE) leading to revisit intention in tourists

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abhijeet Vikramaditya Tiwari ◽  
Naval Bajpai ◽  
Deependra Singh ◽  
Vishal Vyas
Keyword(s):  
Structural Equation ◽  
Sampling Technique ◽  
Mediating Effect ◽  
Content Type ◽  
Significant Relationships ◽  
Revisit Intention ◽  
Tourism Experience ◽  
Main Component ◽  
Relationship Of ◽  
The Relationship

Purpose This study aims to examine the hedonism attributes, memorable tourism experience (MTE), revisit intention and their relationships. This study explores the antecedents of hedonism as physical environment, shopping at the destination, service quality, personalisation and exclusivity that influence MTE. The relationship of hedonism factors with revisit intention is also investigated in light of the mediation of MTE between them. Design/methodology/approach For this study, a sample of 600 tourists is collected by using the convenience sampling technique. The collected data is analysed by using the confirmatory factor analysis-structural equation modelling approach. Findings The empirically validated model recommends the significant relationships between the hedonism elements and revisits intention with the mediating effect of MTE. The findings suggest that tourists who positively perceive hedonism attributes are more likely to have positive MTEs, and they revisit the destination. Originality/value This research study examines the relationship of hedonism determinants with MTE of the tourists leading to their revisit intention for a tourism destination. It helps to understand MTE as the main component to affect tourists’ revisit intention for a destination and make sustainable tourism.

Development of an integrated framework of LGSS strategies for Indian manufacturing firms to improve business performance: an empirical study

2020 ◽  
Vol 33 (1) ◽  
pp. 257-291 ◽  
Author(s):  
Lokpriya Gaikwad ◽  
Vivek Sunnapwar
Keyword(s):  
Six Sigma ◽  
Positive Impact ◽  
Manufacturing Sector ◽  
Manufacturing Firms ◽  
Manufacturing Industries ◽  
Environmental Benefits ◽  
Future Research ◽  
Continuous Growth ◽  
Content Type ◽  
Indian Industries

PurposeThis article aims to explore synergies between Lean, Green and Six Sigma practices in order to propose an integrated LGSS framework for continuous and incremental improvement in the Indian manufacturing industries. The three-dimensional LGSS framework seeks to provide various combinations and support operational, financial, environmental and social needs.Design/methodology/approachIn the research method, first, the current problems faced by Indian manufacturing industries are considered and proposition of a conceptual framework that qualitatively integrates synergistic aspects of Lean, Green and Six Sigma practices, and second, the framework is checked by a survey taken from 203 Indian firms by using SPSS-AMOS.FindingsThe hypothesized result suggests that the positive impact of integrated practices on firm performance in terms of operational, financial, social and environmental outcomes. It also provides a systemic and holistic approach to problem-solving through constant and incremental enhancement in the manufacturing sector.Research limitations/implicationsIn this research, only Indian manufacturing industries have been studied but can be extending into different geographical areas and sectors. Future research is also possible for different behavior and characteristics of companies that can lead to recommending strategies on how companies can improve performance. Most importantly, future research can try to understand which specific practice can contribute to competitive advantage and business success.Practical implicationsManufacturing firms that want to improve environmental sustainability should implement integrated LGSS practices into their supply chain. The set of combined practices improves operational, social, economical and environmental benefits.Social implicationsThe research presents an integrated approach of LSS for the manufacturing industry which leads their business processes to achieve economic sustainability through continuous growth and improved operational efficiency. Manufacturing industries result in outcomes like reduced cost, lead time, improved quality, sustainable market position, profitability, customer satisfaction, etc.Originality/valueThis research is different from previous studies because it integrates Lean, Green and Six Sigma practices into a unique framework that fulfills a specific need of the Indian manufacturing sector that guides operational, social, environmental and financial issues in Indian industries.

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