A Study on the Analysis of CO2 Emissions of Apartment Housing in the Construction Process

Recent research in the construction industry has focused on the reduction of CO2 emission using quantitative assessment of building life. However, most of this research has focused on the operational stage of a building’s life cycle. Few comprehensive studies of CO2 emissions during building construction have been performed. The purpose of this study is to analyze the CO2 emissions of an apartment housing during the construction process. The quantity of CO2 emissions associated with the utilization of selected building materials and construction equipment were used to estimate the CO2 emissions related to the apartment housing life cycle. In order to set the system boundary for the construction materials, equipment, and transportation used, 13 types of construction work were identified; then the CO2 emissions produced by the identified materials were calculated for each type of construction work. The comprehensive results showed that construction work involving reinforced concrete accounted for more than 73% of the total CO2 emissions. The CO2 emissions related to reinforced concrete work was mainly due to transportation from the supplier to the construction site. Therefore, at the time that reinforced concrete is being supplied, shipping distance and fuel economy management of concrete transportation vehicles should be considered thoroughly for significant reduction of CO2 emissions

Optical Properties of Crystalline α-Lactose Monohydrate in Terahertz Range

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Quantitative Analysis of Tris-HCl Buffer using THz Time Domain Spectroscopy

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THz Vibration Spectroscopy of Crystalline α-Lactose Monohydrate

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Study of Human Lymph Nodes using Terahertz Imaging

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Study of Human Articular Cartilage for THz Biomedical Sensing

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Improving the efficiency of homologous recombination by chemical and biological approaches in Yarrowia lipolytica.

Gene targeting is a challenge in Yarrowia lipolytica (Y. lipolytica) where non-homologous end-joining (NHEJ) is predominant over homologous recombination (HR). To improve the frequency and efficiency of HR in Y. lipolytica, the ku70 gene responsible for a double stand break (DSB) repair in the NHEJ pathway was disrupted, and the cell cycle was synchronized to the S-phase with hydroxyurea, respectively. Consequently, the HR frequency was over 46% with very short homology regions (50 bp): the pex10 gene was accurately deleted at a frequency of 60% and the β-carotene biosynthetic genes were integrated at the correct locus at an average frequency of 53%. For repeated use, the URA3 marker gene was also excised and deleted at a frequency of 100% by HR between the 100 bp homology regions flanking the URA3 gene. It was shown that appropriate combination of these chemical and biological approaches was very effective to promote HR and construct genetically modified Y. lipolytica strains for biotechnological applications

Efficiency of gene deletion.

<p>Cells treated or untreated with HU were transformed with a <i>pex10</i>-deletion cassette with 50 bp of homology arm to the <i>pex10</i> gene. The <i>pex10</i> deletion rates (%) are shown and the number of total transformants screened is included in parentheses. WT indicates the wild-type <i>Y</i>. <i>lipolytica</i> Po1f strain. The experiments were performed in duplicate.</p

Propionyl-CoA dependent biosynthesis of 2-hydroxybutyrate containing polyhydroxyalkanoates in metabolically engineered Escherichia coli

We have previously reported in vivo biosynthesis of 2-hydroxyacid containing polyesters including polylactic acid (PLA), poly(3-hydroxybutyrate-co-lactate) [P(3HB-co-LA)], and poly(3-hydroxybutyrate-co-2-hydroxybutyrate-co-lactate) [P(3HB-co-2HB-co-LA)] employing metabolically engineered Escherichia coli strains by the introduction of evolved Clostridium propionicum propionyl-CoA transferase (Pct(Cp)) and Pseudomonas sp. MBEL 6-19 polyhydroxyalkanoate (PHA) synthase I (PhaC1(Ps6-19)). In this study, we further engineered in vivo PLA biosynthesis system in E. coli to synthesize 2HB-containing PHA, in which propionyl-CoA was used as precursor for 2-ketobutyrate that was converted into 2HB-00A by the sequential actions of Lactococcus lactis (a)-2-hydroxybutyrate dehydrogenase (PanE) and Pct(Cp) and then 2HB-00A was polymerized by PhaC1(Ps6-19). The recombinant E. coli XL1-blue expressing the phaC1437 gene, the pct540 gene, and the Ralstonia eutropha prpE gene together with the panE gene could be grown to 0.66 g/L and successfully produced P(70 mol%3HB-co-18 mol%2HB-co-12 mol%LA) up to the PHA content of 66 wt% from 20 g/L of glucose, 2 g/L of 3 HB and 1 g/L of sodium propionate. Removal of the prpC gene in the chromosome of E. coli XLI -blue could increase the mole fraction of 2HB in copolymer, but the PHA content was decreased.The metabolic engineering strategy reported here suggests that propionyl-CoA can be successfully used as the precursor to provide PHA synthase with 2HB-CoA for the production of PHAs containing 2HB monomer. (C) 2013 Elsevier B.V. All rights reserved

Metabolic engineering of Escherichia coli for the production of 5-aminovalerate and glutarate as C5 platform chemicals

5-Aminovalerate (5AVA) is the precursor of valerolactam, a potential building block for producing nylon 5, and is a C5 platform chemical for synthesizing 5-hydroxyvalerate, glutarate, and 1,5-pentanediol. Escherichia coli was metabolically engineered for the production of 5-aminovalerate (5AVA) and glutarate. When the recombinant E. coli WL3110 strain expressing the Pseudomonas putida davAB genes encoding delta-aminovaleramidase and lysine 2-monooxygenase, respectively, were cultured in a medium containing 20. g/L of glucose and 10. g/L of l-lysine, 3.6. g/L of 5AVA was produced by converting 7. g/L of l-lysine. When the davAB genes were introduced into recombinant E. coli strainXQ56allowing enhanced l-lysine synthesis, 0.27 and 0.5. g/L of 5AVA were produced directly from glucose by batch and fed-batch cultures, respectively. Further conversion of 5AVA into glutarate could be demonstrated by expression of the P. putida gabTD genes encoding 5AVA aminotransferase and glutarate semialdehyde dehydrogenase. When recombinant E. coli WL3110 strain expressing the davAB and gabTD genes was cultured in a medium containing 20. g/L glucose, 10. g/L l-lysine and 10. g/L α-ketoglutarate, 1.7. g/L of glutarate was produced