• Title/Summary/Keyword: Key green technology

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Policies to Promote Green Economy Innovation in East Asia and North America

  • Barbier, Edward B.
    • STI Policy Review
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    • v.6 no.1
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    • pp.54-69
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    • 2015
  • Although there is progress in developing green sectors in North America and East Asia, the key challenge facing the expansion of economy-wide green innovation and structural change in these regions is the absence of relevant policy follow-up to the green stimulus enacted during the Great Recession. The boost to green sectors provided by such measures is waning quickly, given that much of the green stimulus focused on energy efficiency. The biggest obstacles to sustaining green growth in North America and East Asiaare major market disincentives, especially the under-pricing of fossil fuels and market failures that inhibit green innovation. A three-part strategy to overcome these obstacles would involve: first, removing fossil fuel subsidies; second, employing market-based instruments to further reduce the social costs of fossil fuel use; and third, allocating any resulting revenue to public support for green innovation and investments. Such a strategy would ensure that green growth is not about promoting niche green sectors but instigating economy-wide innovation and structural transformation in North America and East Asia.

Acid-Base Bifunctional Metal-Organic Frameworks: Green Synthesis and Application in One-Pot Glucose to 5-HMF Conversion

  • Zhang, Yunlei;Jin, Pei;Meng, Minjia;Gao, Lin;Liu, Meng;Yan, Yongsheng
    • Nano
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    • v.13 no.11
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    • pp.1850132.1-1850132.14
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    • 2018
  • The direct synthesis of metal-organic frameworks (MOFs) with acidic and basic active sites is challenging due to the introduction of functional groups by post-functionalization method often jeopardize the framework integrity. Herein, we report the direct synthesis of acid-base bifunctional MOFs with tuning acid-base strength. Employing modulated hydrothermal (MHT) approach, microporous MOFs named $UiO-66-NH_2$ was prepared. Through the ring-opening reaction of 1,3-propanesultone with amino group, $UiO-66-NH_2-SO_3H-type$ catalysts can be obtained. The synthesized catalysts were well characterized and their catalytic performances were evaluated in one-pot glucose to 5-HMF conversion. Results revealed the acid-base bi-functional catalyst possessed high activity and excellent stability. This work provides a general and economically viable approach for the large-scale synthesis of acid-base bi-functional MOFs for their potential use in catalysis field.

Styrene Epoxidation over Cobalt Cyclam Immobilized SBA-15 Catalyst

  • Sujandi;Prasetyanto, Eko Adi;Han, Sang-Cheol;Park, Sang-Eon
    • Bulletin of the Korean Chemical Society
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    • v.27 no.9
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    • pp.1381-1385
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    • 2006
  • Cobalt (cyclam) complex has been successfully immobilized onto SBA-15, and proven to be an active catalyst for the epoxidation of styrene with tert-butyl hydroperoxide as a terminal oxidant. The selectivity for styrene oxide was observed to be up to 66% with 40% styrene conversion after 12h reaction time. The reversible redox cycle between Co(III) and Co(II) couple which was supposed to play key role during the epoxidation reaction was supported by a cyclic voltametry analysis. The textural properties of the catalyst was characterized by XRD, N2 adsorption-desorption, and TEM analysis.

The Green Cement for 3D Printing in the Construction Industry

  • Park, Joochan;Jung, Euntae;Jang, Changsun;Oh, Chaewoon;Shin, Kyung Nam
    • Journal of Energy Engineering
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    • v.29 no.3
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    • pp.50-56
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    • 2020
  • Currently, 3D printing technology is a new revolutionary additive manufacturing process that can be used for making three dimensional solid objects from digital films. In 2019, this 3D printing technology spreading vigorously in production parts (57%), bridge production (39%), tooling, fixtures, jigs (37%), repair, and maintenance (38%). The applications of 3D printing are expanding to the defense, aerospace, medical field, and automobile industry. The raw materials are playing a key role in 3D printing. Various additive materials such as plastics, polymers, resins, steel, and metals are used for 3D printing to create a variety of designs. The main advantage of the green cement for 3D printing is to enhance the mechanical properties, and durability to meet the high-quality material using in construction. There are several advantages with 3D printing is a limited waste generation, eco-friendly process, economy, 20 times faster, and less time-consuming. This research article reveals that the role of green cement as an additive material for 3D printing.

Acid green-25 removal from wastewater by anion exchange membrane: Adsorption kinetic and thermodynamic studies

  • Khan, Muhammad Imran;Ansari, Tariq Mahmood;Zafar, Shagufta;Buzdar, Abdul Rehman;Khan, Muhammad Ali;Mumtaz, Fatima;Prapamonthon, Prasert;Akhtar, Mehwish
    • Membrane and Water Treatment
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    • v.9 no.2
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    • pp.79-85
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    • 2018
  • In this work, batch adsorption of anionic dye acid green-25 (AG-25) from aqueous solution has been carried out at room temperature using anion exchange membrane (DF-120B) as a noval adsorbent. The effect of various experimental parameters such as contact time, membrane dosage, ionic strength and temperature on the adsorption of dye were investigated. Kinetic models namely pseudo-first-order, pseudo-second-order, Elovich, liquid film diffusion, Bangham and modified freundlich models were employed to evaluate the experimental data. Parameters like adsorption capacities, rate constant and related correlation coefficients for every model are calculated and discussed. It showed that adsorption of AG-25 onto DF-120B followed pseudo-first-order rate expression. Thermodynamic study indicates that adsorption of AG-25 onto DF-120B is an exothermic and spontaneous process.

Green Cooperative Sensing Scheme in Heterogeneous Networks

  • Shen, Lifei;Liu, Jian;Tan, Xinxin;Wang, Lei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.2
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    • pp.550-565
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    • 2018
  • Cognitive radio technology is still the key technology of future mobile communication systems. Previous studies have focused on improving spectrum utilization and less energy consumption. In this paper, we propose an Overhead Reduced Scheme (ORS) for green cooperative spectrum sensing. Compared to traditional cooperative sensing scheme, ORS scheme divides the sensing time into three time slots and selects the best multi-mode user to report decisions. In consideration of reporting channel deviation, we derive closed-form expressions for detection probability and false alarm probability of ORS scheme based on Rayleigh fading channel. Simulation results show that ORS scheme can improve the perception accuracy while reducing the perceived delay and energy consumption in the process of perception, so as to realize the green communication.

Construction and Analysis of Food-Grade Lactobacillus kefiranofaciens β-Galactosidase Overexpression System

  • He, Xi;Luan, MingJian;Han, Ning;Wang, Ting;Zhao, Xiangzhong;Yao, Yanyan
    • Journal of Microbiology and Biotechnology
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    • v.31 no.4
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    • pp.550-558
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    • 2021
  • Lactobacillus kefiranofaciens contains two types of β-galactosidase, LacLM and LacZ, belonging to different glycoside hydrolase families. The difference in function between them has been unclear so far for practical application. In this study, LacLM and LacZ from L. kefiranofaciens ATCC51647 were cloned into constitutive lactobacillal expression vector pMG36e, respectively. Furtherly, pMG36n-lacs was constructed from pMG36e-lacs by replacing erythromycin with nisin as selective marker for food-grade expressing systems in Lactobacillus plantarum WCFS1, designated recombinant LacLM and LacZ respectively. The results from hydrolysis of o-nitrophenyl-β-galactopyranoside (ONPG) showed that the β-galactosidases activity of the recombinant LacLM and LacZ was 1460% and 670% higher than that of the original L. kefiranofaciens. Moreover, the lactose hydrolytic activity of recombinant LacLM was higher than that of LacZ in milk. Nevertheless, compare to LacZ, in 25% lactose solution the galacto-oligosaccharides (GOS) production of recombinant LacLM was lower. Therefore, two β-galactopyranosides could play different roles in carbohydrate metabolism of L. kefiranofaciens. In addition, the maximal growth rate of two recombinant strains were evaluated with different temperature level and nisin concentration in fermentation assay for practical purpose. The results displayed that 37℃ and 20-40 U/ml nisin were the optimal fermentation conditions for the growth of recombinant β-galactosidase strains. Altogether the food-grade Expression system of recombinant β-galactosidase was feasible for applications in the food and dairy industry.

Behaviour of FRP composite columns: Review and analysis of the section forms

  • Rong, Chong;Shi, Qingxuan;Zhao, Hongchao
    • Advances in concrete construction
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    • v.9 no.2
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    • pp.125-137
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    • 2020
  • As confining materials for concrete, steel and fibre-reinforced polymer (FRP) composites have important applications in both the seismic retrofit of existing reinforced concrete columns and in the new construction of composite structures. We present a comprehensive review of the axial stress-strain behaviour of the FRP-confined concrete column. Next, the mechanical performance of the hybrid FRP-confined concrete-steel composite columns are comprehensively reviewed. Furthermore, the results of FRP-confined concrete column experiments and FRP-confined circular concrete-filled steel tube experiments are presented to study the interaction relationship between various material sections. Finally, the combinations of material sections are discussed. Based on these observations, recommendations regarding future research directions for composite columns are also outlined.

Association of Methylation of the RAR-β Gene with Cigarette Smoking in Non-Small Cell Lung Cancer with Southern-central Chinese Population

  • Li, Wen;Deng, Jing;Wang, Shuang-Shuang;Ma, Liang;Pei, Jiang;Zeng, Xiao-Xi;Tang, Jian-Xin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.24
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    • pp.10937-10941
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    • 2015
  • Pathogenesis of lung cancer is a complicated biological process including multiple genetic and epigenetic changes. Since cigarette smoking is confirmed as the most main risk factor of non-small cell lung cancer (NSCLC), the aim of this study was to determine whether tobacco exposure plays a role in gene methylation. Methylation of the RAR-${\beta}$ gene were detected using methylation-specific polymerase chain reaction in DNA from 167 newly diagnosed cases with NSCLC and corresponding 105 controls. A significant statistical association was found in the detection rate of the promoter methylation of RAR-${\beta}$ gene between NSCLC and controls ($x^2$=166.01; p<0.01), and hypermethylation of the RAR-${\beta}$ gene was significantly associated with smoking status (p=0.038, p<0.05). No relationship was found between RAR-${\beta}$ gene methylation and pathologic staging including clinical stage, cell type, gender and drinking (p>0.05), and the methylation of RAR-${\beta}$ gene rate of NSCLC was slightly higher in stages III+IV (80.0%) than in I+II (70.8%). Similar results were obtained for methylation of the RAR-${\beta}$ gene between squamous cell carcinoma (77.9%) and other cell type lung cancer (73.9%). These results showed that the frequency of methylation increased gradually with the development of clinical stage in smoking-associated lung cancer patients, and tobacco smoke may be play a potential role in RAR-${\beta}$ gene methylation in the early pathogenesis and process in lung cancer, particularly squamous cell carcinoma. Aberrant promoter methylation is considered to be a promising marker of previous carcinogen exposure and cancer risk.

Schedule Management for Green Building Projects in Singapore: Schedule Delay, Causal Factors and Solutions

  • Hwang, Bon-Gang;Zhao, Xianbo;Leong, Lay Peng
    • International conference on construction engineering and project management
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    • 2015.10a
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    • pp.527-531
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    • 2015
  • With the mounting concerns over environmental issues, green construction is gaining a place in the global construction industry. However, rare research has been conducted to analyze green construction projects, especially in the aspect of project schedule performance. As a result, this study aims to investigate the degree of project delay in green building construction, analyze the factors affecting schedule delay of green building projects, and finally provide recommendations to improve schedule performance of green building project. To achieve the objectives, a comprehensive literature review was carried out, followed by a survey conducted with 30 companies that provided data from 220 traditional and 96 green building projects. The analysis of the responses identified that 15.9% of the traditional building projects were delayed while 32.3% of the green building projects were completed behind schedule. Furthermore, the amount of the delays in green building projects was an average of 4.8% of their planned schedule. The top 5 critical factors that can cause delay in green building projects were identified as: (1) speed of decision-making by clients; (2) speed of decision-making involving all project teams; (3) communication/coordination between key parties; (4) level of experience of consultants; and (5) difficulties in contractors' project financing. Lastly, a list of recommendations was introduced, aiming to reduce schedule delay in green building construction projects based on the observations. This study will serve as s a base for further research on the enhancement of green building project schedule performance.

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