• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2403-2407
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• 2013

The hybrid density-functional (B3LYP/6-31G(d,p)) method was used to analyze the substitution effect on the $C_{20}H_{20}$ cage based on calculation of the frontier orbitals of fifteen $C_{20}H_{17}(OH)_3$ derivatives. All substitution products were geometrically optimized without constraints and confirmed by frequency analysis. The results suggest that the cis-1 cis-1 cis-2 regioisomer is the most stable isomer, which implies that hydrogen bonding exerts a stronger effect on the relative energies of the trihydroxide than long-range interactions. Thus, this supports the experimental result in which the bisvicinal tetrol was of particular preparative-synthetic interest. While the LUMO of each of the $C_{20}H_{17}(OH)_3$ regioisomers was equivalently delocalized over the void within the cage, the HOMO was limitedly delocalized on substituents and carbons in close proximity to the substituents. The characteristics of the HOMO of each of the regioisomers vary based on the substitution sites. This indicates that the 15 regioisomers of each $C_{20}H_{20}$ trisubstituted derivative might undergo an entirely different set of characteristic chemical reactions with electrophilic reagents. The results further suggest that the penta-substituted OH groups on the surface of the fullerene cage are more likely to be localized on a pentagon than to be homogeneously delocalized.

• Korean Journal of Construction Engineering and Management
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• v.15 no.1
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• pp.78-86
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• 2014

Modular system is a construction method which installs factory-manufactured units on site. It enables to reduce the duration and improve the quality of the construction. Nevertheless, the unit modular system is restrictively applied to domestic market such as barracks, education facilities, low-rise housing. To motivate the application of unit modular system, this study figures out important attributes of the unit modular system in a domestic construction market. Finally this study suggest marketing strategies and influential factors by Importance-Performance Analysis(IPA) based on those attributes focusing on the apartment housing. As a result, Unit modular System in the domestic market has strength on constructability, but it show weakness on usability and economic aspects which are more important in apartment housing market. Thus an improved technology in usability and economic aspects are required to activate the market.

• Applied Chemistry for Engineering
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• v.30 no.3
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• pp.331-336
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• 2019

In this study, required properties and optimized procedure conditions for the pitch based soft carbon anode of lithium ion battery was investigated for improving the initial efficiency and rate performance. Each petroleum residue was thermally treated at 360, 370, and $410^{\circ}C$ for 3 hours to synthesis a pitch and the corresponding pitch shows the softening point of 86, 98, and $152^{\circ}C$, respectively. The elemental analysis and thermal characteristics of the pitch were investigated by EA analysis and TGA. It was noted that the low H/C and improved thermal stability were obtained with the high softening point. The obtained pitch was carbonized at $1,200^{\circ}C$ for 1 hour to produce a soft carbon based anode. As a result of investigating the crystal structure by XRD analysis, it was found that the crystallinity of soft carbon increased with increasing the softening point. It was considered that relatively higher boiling components and decreases in the evaporation component resulted the components participation for cyclization during the heat treatment process. The soft carbon based anode with an improved crystallinity shows the enhanced initial efficiency and rate performance. The mechanism of both improvements was also discusssed based on the developed crystal structure of soft carbon based anode materials.

• Advances in Energy Research
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• v.4 no.4
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• pp.275-284
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• 2016

In the present work, ZnO nanoparticles (NPs) have been dispersed alone in the same solvent of the active layer for improving performance parameters of the organic solar cells. Different concentrations of the ZnO NPs have been blended inside active layer of the solar cell based on poly(3-hexylthiophene) (P3HT), which forms the hole-transport network, and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), which forms the electron-transport network. In the present investigations, the ZnO NPs may represent an efficient tool for improving light harvesting through light scattering inside active layer, electron mobility, and electron acceptance strength which tend to improve photocurrent and performance parameters of the investigated solar cell. The fill factor (FF) of the ZnO-doped solar cell increases nearly 14% compared to the non-doped solar cell when the doping is 50%. The present investigations show that ZnO NPs improve power conversion efficiency of the solar cell from 1.23% to 1.64% with increment around 25% that takes place after incorporation of 40% as a volume ratio of the ZnO NPs inside P3HT:PCBM active layer.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.235-243
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• 2010

For decades, traditional mutation breeding technologies using spontaneous mutation, chemicals, or conventional radiation sources have contributed greatly to the improvement of crops and microorganisms of agricultural and industrial importance. However, new mutagens that can generate more diverse mutation spectra with minimal damage to the original organism are always in need. In this regard, ion beam irradiation, including proton-, helium-, and heavier-charged particle irradiation, is considered to be superior to traditional radiation mutagenesis. In particular, it has been suggested that ion beams predominantly produce strand breaks that often lead to mutations, which is not a situation frequently observed in mutagenesis induced by gamma-ray exposure. In this review, we briefly describe the general principles and history of particle accelerators, and then introduce their successful application in ion beam technology for the improvement of crops and microbes. In particular, a 100-MeV proton beam accelerator currently under construction by the Proton Engineering Frontier Project (PEFP) is discussed. The PEFP accelerator will hopefully prompt the utilization of ion beam technology for strain improvement, as well as for use in nuclear physics, medical science, biology, space technology, radiation technology and basic sciences.

• Asia-Pacific Journal of Business
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• v.10 no.2
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• pp.1-12
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• 2019

Collaborative research and development (R&D) has been encouraged based on the belief that knowledge spill-over is mutually beneficial for partners. Although the benefits are supported by science and technology policy research, the risk of R&D collaboration has not been extensively discussed. Two independent studies suggest that there are risks associated with the overuse of collaborative research frameworks. Two sets of R&D collaboration data were analyzed: between the national bio-technology research program and 1) Data Envelop Analysis (DEA), and 2) between Stochastic Frontier Analysis (SFA). In the case of SFA, output measures were integrated into a single output, with weights extracted from research programme managers' responses to the questionnaire. While the DEA result demonstrated the inefficiency of collaborative research, SFA did not. Unlike previous research highlighting risks associated with disclosing proprietary R&D and potential conflict of interest, our study indicates that the transaction's social cost affects collaborative research efficiency. Therefore, governments promoting R&D collaborations should be carefully managed, and policy makers must reconsider the strict conditions governing compulsory collaborative R&D programs.

• Asian Journal of Atmospheric Environment
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• v.5 no.3
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• pp.164-171
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• 2011

This work focuses on the analysis of bioaerosols in the atmosphere at higher altitudes over Noto Peninsula, Japan. We carried out direct sampling via aircraft, separated cultures, and identified present isolates. Atmospheric bioaerosols at higher altitudes were collected using a Cessna 404 aircraft for an hour at an altitude of 3,500 m over the Noto Peninsula. The aircraft-based direct sampling system was devised to improve upon the system of balloon-based sampling. In order to examine pre-existing microorganism contamination on the surface of the aircraft body, bioaerosol sampling was carried out just before takeoff using the same method as atmospheric sampling. Identification was carried out by a homology search for 16S or 18S rDNA isolate sequences in DNA databases (GenBank). Isolate sampling just before takeoff revealed Stretpomyces sp., Micrococcus sp., and Cladosporium sp. One additional strain, Bacillus sp., was isolated from the sample after bioaerosol collection at high altitude. As the microorganism contamination on the aircraft body before takeoff differed from that while in the air, the presence of additional, higher atmosphere-based microorganisms was confirmed. It was found that Bacillus sp. was floating at an altitude of 3,500 m over Noto Peninsula.

• Journal of Energy Engineering
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• v.26 no.3
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• pp.97-104
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• 2017

In this study, waste tire rubbers were pyrolyzed in a lab-scale pyrolysis plant equipped with a fluidized bed reactor in a temperature ranges of $450-650^{\circ}C$. The main object of this work is to investigate the properties of pyrolysis oil with reaction temperatures and the behavior of sulfur in the products when waste polypropylene was added for co-pyrolysis. The maximum yield of oil was about 52wt.% at the reaction temperature of $456^{\circ}C$. From GC-MS analysis, the pyrolysis oils consisted mainly of limonene, toluene, xylene, styrene, trimethylbenzene, methylnaphthalenes and some heteroatom(sulfur and nitrogen)-containing compounds. The addition of waste polypropylene resulted in decrease in sulfur contents of the pyrolysis oils.

• Transactions of the KSME C: Technology and Education
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• v.5 no.1
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• pp.69-77
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• 2017

Nanotechnology, along with Information Technology (IT) and Bio-technology (BT), has been regarded as a core area that will drive technological revolution of $21^{st}$ century. South Korea and other countries with advanced scientific and technological research programs are investing heavily in the field, and among its various aspects, nanomaterial industry is considered to be at the heart of this global competition. In this review, we look at nanomaterials industry from the perspective of mechanical engineering. Nanomaterials exhibit unique characteristics differing from those of micron, or sub-micron sized materials, and hence are potentially able to open up new opportunities. Specifically, environmental and biological sciences, energy, and catalysis are areas that are expected to benefit from these developments.

• Journal of Microbiology and Biotechnology
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• v.22 no.7
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• pp.902-906
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• 2012

Expressed sequence tags (ESTs) from the Antarctic green algae Pyramimonas gelidicola were analyzed to obtain molecular information on cold acclimation of psychrophilic microorganisms. A total of 2,112 EST clones were sequenced, generating 222 contigs and 219 singletons, and 200 contigs and 391 singletons from control ($4^{\circ}C$) and cold-shock conditions ($-2^{\circ}C$), respectively. The complete EST sequences were deposited to the DDBJ EST database (http://www.ddbj.nig.ac.jp/index-e.html) and the nucleotide sequences reported in this study are available in the DDBJ/EMBL/GenBank. These EST databases of Antarctic green algae can be used in a wide range of studies on psychrophilic genes expressed by polar microorganisms.