• Korean Journal of Construction Engineering and Management
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• v.8 no.6
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• pp.150-158
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• 2007

As the amount of $CO_2$ emission in Korea is ranked 9th and the increasing rate of $CO_2$ emissions highest in the world, it is strongly necessary to devise methods to decrease the amount of $CO_2$ in each industry as the basis of establishing environmentally sustainable production system. This paper aims to identify the characteristics of $CO_2$ emissions from construction wastes throughout the simplified LCA (Life Cycle Assessment) and suggest the strategic guideline for the construction waste management plan to decrease $CO_2$. As a result of LCA on the case of a high-rise residential building project, total sum of $CO_2$ emission generated from construction wastes appeared as 6,818,123kg-$CO_2$ and $CO_2$ emission per unit floor area as 21.01kg-$CO_2/{\beta}{\ge}$. The principal waste materials generating more than 95% of $CO_2$ are materials such as reinforcing bar, temporary materials, cement, ready-mixed-concrete, concrete products, and tile, which have relatively high unit emission rate of $CO_2$ in the process of production. Besides, more than 92% of $CO_2$ was generated from the activities such as structure work, plaster work, temporary work, and tile and stone work, which are generally executed in the early phase of the whole construction period. Reflecting these results, the guideline for the construction waste management plan was recommended. If the waste management plan is established considering the guideline suggested, there would be high potential to decrease the amount of $CO_2$ generated from construction wastes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.7
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• pp.801-808
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• 2017

The present study investigated the protective effects of Bifidobacterium bifidum culture supernatants (BbSC) and intracellular cell-free extracts (BbICFE) on human dermal fibroblasts (HDFs) against ultraviolet-B (UV-B) irradiation. HDFs were treated with UV-B, UV-B+BbCS, and UV-B+BbICFE. Treatment of UV-B-irradiated HDFs with BbCS and BbICFE significantly increased cell viability compared to UV-B-irradiated HDFs. BbCS treatment reduced senescence in HDFs by approximately 40.0%. Moreover, sub-G1 phase was significantly reduced in BbCS- and BbICFE-treated HDFs (3.3% and 4.5%, respectively). The effect of UV-B on oxidative damage of HDFs was measured by dichlorofluorescin diacetate. Fluorescence intensity significantly increased in UV-B-irradiated HDFs. Inhibition of cellular reactive oxygen species in HDFs treated with 0.01% BbCS was the highest at 34.1%. Levels of p21 and p53 protein expression induced by UV-B irradiation were reduced by treatment with BbCS and BbICFE (47.0% and 35.6%, respectively). These results show that BbCS and BbICFE reduce UV-B-induced cellular senescence and apoptosis in HDFs. Thus, BbCS and BbICFE can be used as potential agents for protection of UV-B-induced skin cell damage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6C
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• pp.505-511
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• 2008

The global navigation satellite system (GNSS) is using a direct sequence/spread spectrum (DS/SS) modulation. In order to recover the information data, the DS/SS system first performs a two-step synchronization process: acquisition and tracking. The acquisition process adjusts the phase difference between the received and locally generated acquisition sequences within ${\pm}T_c/2$ or less, where $T_c$ is the chip period. The tracking process performs fine synchronization. In this paper, we focus on the tracking issue. The single delta delay locked loop($\Delta$-DLL) is the optimal tracking scheme for a GNSS in the absence of multipath signals, where $\Delta$ means the spacing between the early and late correlation time offset. In the multipath environments, however, the $\Delta$-DLL suffers from huge estimation bias(denoted by $\beta$) caused by distorted correlation values. Although some modified schemes such as a $\Delta$-DLL with a narrow $\Delta$ and a double delta DLL (${\Delta}^{(2)}$-DLL) were proposed to reduce the estimation bias, they cannot remove the estimation bias completely and need more accurate acquisition process. This paper proposes a novel tracking scheme that can dramatically reduce the estimation bias, using the maximum slope change among the correlation outputs.

• Current Photovoltaic Research
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• v.1 no.1
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• pp.38-43
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• 2013

$Cu(In,Ga)_3Se_5$ is a candidate material for the top cell of $Cu(In,Ga)Se_2$ tandem cells. This phase is often found at the surface of the $Cu(In,Ga)Se_2$ film during $Cu(In,Ga)Se_2$ cell fabrication, and plays a positive role in $Cu(In,Ga)Se_2$ cell performance. However, the exact properties of the $Cu(In,Ga)_3Se_5$ film have not been extensively studied yet. In this work, $Cu(In,Ga)_3Se_5$ films were fabricated on Mo-coated soda-lime glass substrates by a three-stage co-evaporation process. The Cu content in the film was controlled by varying the deposition time of each stage. X-ray diffraction and Raman spectroscopy analyses showed that, even though the stoichiometric Cu/(In+Ga) ratio is 0.25, $Cu(In,Ga)_3Se_5$ is easily formed in a wide range of Cu content as long as the Cu/(In+Ga) ratio is held below 0.5. The optical band gap of $Cu_{0.3}(In_{0.65}Ga_{0.35})_3Se_5$ composition was found to be 1.35eV. As the Cu/(In+Ga) ratio was decreased further below 0.5, the grain size became smaller and the band gap increased. Unlike the $Cu(In,Ga)Se_2$ solar cell, an external supply of Na with $Na_2S$ deposition further increased the cell efficiency of the $Cu(In,Ga)_3Se_5$ solar cell, indicating that more Na is necessary, in addition to the Na supply from the soda lime glass, to suppress deep level defects in the $Cu(In,Ga)_3Se_5$ film. The cell efficiency of $CdS/Cu(In,Ga)_3Se_5$ was improved from 8.8 to 11.2% by incorporating Na with $Na_2S$ deposition on the CIGS film. The fill factor was significantly improved by the Na incorporation, due to a decrease of deep-level defects.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.236-242
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• 2005

To develop a new detection method using irradiation-induced volatile marker compounds of red pepper powder (RP), the volatile compounds of irradiated RP (0, 1, 3, 5, and 10 kGy) were analyzed by purge and trap (P&T)/solid phase microextraction (SPME)/gas chromatography/mass spectrometry (GC/MS) methods. A total of 51 and 31 compounds were detected in IRP by SPME and P&T methods, respectively. Among these, 25 compounds, which were composed of 4 hydrocarbons, 7 aldehydes, 1 ketone, 3 alcohols, 4 aromatic compounds, 2 esters and 4 miscellaneous compounds, showed irradiation dependent manner with significant positive correlation (p<0.01 or p<0.05) between irradiation dose and relative concentration. However, all compounds except 1,3-bis(1,1-dimethylethyl)benzene were not suitable as marker compounds because of their low determination coefficients ($R^2$<0.80) between irradiation dose and their concentrations, and detectablilty in nonirradiated sample. Therefore, only one compound, 1,3-bis(1,1-dimethylethyl)benzene, was tentatively identified as a volatile marker compound to detect irradiated RP.

• Clinical and Experimental Reproductive Medicine
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• v.15 no.2
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• pp.135-147
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• 1988

To compare the stimulation effect of the ratio in follicle stimulating hormone and luteinizing hormone in induction of multiple follicular growth, the serum $E_2$ level, the diameter of follicle, number of aspirated follicles and cleavage rate of in vitro fertilized preovulatory oocytes as well as the pregnancy rate were evaluated. Forty one patients with irreparable tubal disease were stimulated by hMG(n=24) or FSH/hMG(n=17) for the purpose of in vitro fertilization and embryo transfer. The following results were obtained. 1. Serum estradiol($E_2$) levels on the day of hCG administration were $921.0{\pm}353.3\;pg/ml$ in hMG group and $1272.9{\pm}1060.6\;pg/ml$ in FSH/hMG group. The serum $E_2$ value of hMG group was significantly lower than that of FSH/hMG group. 2. The diameter of leading follicle by ultrasonogram on the day of hCG administration were $16.2{\pm}2.0\;mm$ in hMG group and $16.2{\pm}2.6\;mm$ in FSH/hMG group. No significant difference of follicle diameter between two groups was demonstrated. 3. The number of follicles with diameter above 10 mm by sonogram on the day of hCG injection were $3.91{\pm}2.32$ in hMG group and $6.52{\pm}3.86$ in FSH/hMG group. There was significant difference of number of follicles between two groups, (p< 0.01). 4. The number of oocytes found per patient at aspiration were $2.59{\pm}1.00$ in hMG group and 3. $76{\pm}2.31$ in FSH/hMG group. There was significant difference of number of aspirated oocytes between two groups. (p< 0.05). 5. The detection rate of preovulatory oocyte at aspiration were 68.4%(39/57) in hMG group (n=22) and 77.6%(38/49) in FSH/hMG group (n=13). 6. The cleavage rate of preovulatory oocyte at 44 hours after insemination were 74.4%(29/39) in hMG group(n=22) and 81.6%(31/38) in FSH/hMG group (n=13). When only hMG was used, one pregnancy was established in 15 patients to whom 29 zygotes were transferred. And a full term normal female baby was delivered by elective cesarean section. In the FSH/hMG group, five pregnancies out of 9 transferred patients were confirmed by serum ${\beta}-hCG$. Two pregnancies were spontaneously aborted before the 6th week of pregnancy. One patient aborted her baby at the 18th week of pregnancy because of incompetent internal os of the cervix. Two patients delivered two full term babies by elective cesarean section. From the above findings, paralell with the increase in the ratio of exogenous follicle stimulating hormone to luteinizing hormone, an increase in oocyte recovery was observed as well as an improvements in pregnancy rate. It was concluded that FSH enrichment early in the follicular phase had a beneficial effect in the controlled ovarian hyperstimulation.

• Proceedings of the Ginseng society Conference
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• 1988.08a
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• pp.122-128
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• 1988

Several major polyacetylene compounds were isolated from the petroleum-ether fraction of fresh Korean ginseng roots through solvent fractionation. partition and silica gel column chromatography. Further separation of acetylenic compounds was accomplished by bonded normal phase HPLC utilizing a moderately nonpolar microparticulate column. The preparative separation for the various spectral measurements was carried out by low pressure preparative liquid chromatography. The chemical structure of these polyacetylenes separated was determined by UV. IR/FTIR. $^{1}H$ NMR. mass spectral and elemental analysis. These are identified to be heptadeca-1-en-4.6-diyn-3.9.l0.-triol [1] heptadeca-1.9-dien-4.6-diyn-3-ol. heptadeca-1.8-dien-4.6-diyn-3.10-diol and the 4th was denatured polyacetylene. heptadeca-1.4-dien-6.8-diyn-3.10-diol. Two different p-substituted benzoates of panaxynol were synthesized for the determination of exciton chirality. The circular dichroism spectra in the UV region show that panaxynol p-bromobenzoate and p-dimethyl-aminobenzoate constitute negative exciton chirality [2]. Isolated major polyacetylene compounds were irradiated in aerated solution with 300 nm UV light to obtain the oxidized product at the allylic alcohol center to corresponding carbonyl compounds such as heptadeca-1-en-4.6-diyn-9.10-diol-3-one and heptadeca-1.9-dien-4.6-diyn-3-one. These photooxidation compounds have en-on-diyne chromophore and undergo nucleophilic addition reaction with methanol to yield ${\beta}-methoxy$ carbonyl compounds such as heptadeca-9-en-4.6-diyn-1-methoxy-3-one and heptadeca-4.6-diyn-1-methoxy-9.10-diol-3-one.

• Journal of the Korean institute of surface engineering
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• v.52 no.6
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• pp.283-288
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• 2019

MCrAlY overaly coatings are used as oxidation barrier coatings to prevent degradation of the underlying substrate in high temperature and oxidizing environment of the hot section of gas turbines. Therefore, oxidation resistance in high temperature is important property of MCrAlY coatings. Also, coefficients of thermal expansion (CTE) of MCrAlY have middle value of that of Ni-based superalloys and oxides, which have the effect of preventing the delamination of the surface oxides. Cyclic oxidation test is one of the most useful methods for evaluating the high temperature durability of coatings used in gas turbines. In this study, NiCoCrAlY overlay coatings were formed on Inconel 792(IN 792) substrates by vacuum plasma spraying process. Vacuum plasma sprayed NiCoCrAlY coatings and IN 792 susbstrates were exposed to 1000℃ one-hour cyclic oxidation environment. NiCoCrAlY coatings showed lower weight gain in short-term oxidation. In long-term oxidation, IN 792 substrates showed higher weight loss due to delamination of surface oxide but NiCoCrAlY coatings showed lower weight loss. X-ray diffraction (XRD) analysis showed α-Al2O3 and NiCr₂O₄ was formed during the cyclic oxidation test. Through cross-section observation using scanning electron microscopy (SEM) and electron back scatter diffraction (EBSD) analysis, thermally grown oxide (TGO) layer composed of α-Al₂O₃ and NiCr₂O₄ was formed and the thickness of TGO increased during 1000℃ cyclic oxidation test. β phase in upper side of NiCoCrAlY coating was depleted due to oxidation of Al and outer beta depletion zone thickness also increased as the cyclic oxidation time increased.

• Journal of Veterinary Clinics
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• v.15 no.1
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• pp.131-139
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• 1998

Progesterone을 함유하고 있는 CIDR(Controlled Internal Drug Release)의 질내삽 입은 황체기를 인위적으로 연장시킬 수 있다. CIDR의 삽입이,삽입시 존재했던 우세난포 (dominant follicle)의 반응과 난포의 발육반응 그리고 2회 또는 3회의 난포주기를 가지고 있는 처려우에서 CIDR의 삽입기간동안 난포의 성장 및 발육에 어떠한 영향을 미치는가를 비교검 토하기 위하여 배란후 16일째의 처녀우 4마리에 7일동안 CIDR를 삽입하였다. CIDR의 삽입 은 발정의 발현을 억제시켰으며 그리고 발정주기의 길이를 정상 발정주기보다 유의성있게 연 장시켰다($26.3{\pm} 0.5 vs 20.8{\pm}$ 1.5일, p<0.05). CIDR의 삽입시 혈장 progesterone 농도는 $3.6{\pm}$ 2.7 ng/ml 이었으며, 17일과 23일 사이에는 2.1-4.4 ng/ml($3.6{\pm}1.2 ng/ml$) 사이를 유지했다. 혈 장 estradiol-179의 농도는 난포의 발육 및 배란전 배란난포의 성숙을 나타내는 특징적인 변화 양상을 나타래었다. 4마리의 처녀우중 2마리는 CIDR 삽입전 발정주기당 2회의 난포주기를 가진 반면, 나머지 2마리는 주기당 3회의 난포주기를 가졌다. 그렇지만 CIDR의 삽입기간동안 모든 처녀우는 주기당 3회의 발정주기를 가졌다. CIDR의 삽입전 발정주기당 3회의 난포주기 를 갖는 처녀우에서 CRR의 삽입은 세 번째 난포주기에서 배란성 우세난포의 우세기 (dominant phase)를 연장시켰다. 3회의 난포주기를 갖는 2마리에서 CIDR의 삽입후 배란난포 는 존속시간과 우세기가 유의성있게 연장되었다. CIDR의 삽입전 발정주기당 2회의 난포주기 를 갖는 다른 2마리의 처녀우에서 CIDR의 삽입후 우세난포는 곧바로 퇴행되었고 새로운 난 포주기를 형성하였으며, 우세난포의 우세기와 배란난포의 존속기간을 연장시키지 않았다. CRR의 삽입은 CIDR의 삽입후 이어지는 발정주기동안 난포의 발육 및 성장에 영향을 미치 지 않았으며 발정주기의 길이, 난포주기, 혈장 progesterone 및 estradiol-179 농도에 영향을 미치지 않았다. 결과적으로 황체기 후반부에 CIDR의 삽입은 CIDR삽입전 발정주기동안 3회 의 난포주기를 갖는 처녀우에서 배란성 우세난포의 발육과 배란까지의 기간을 연장시켰고 2회 난포주기를 갖는 처녀우에서는 우세난포를 곧바로 퇴행시킨후, 새로운 난포주기를 형성 하였다.

• Korean Journal of Microbiology
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• v.34 no.4
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• pp.212-218
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• 1998

An obligately methylotrophic bacterium which produces extracellular polysaccharide (EPS) was isolated through methanol-enrichment culture technique. The isolate was aerobic, nonmotile, and gram negative rod and exibited catalase, but no oxidase, activity. Plasmid, carotenoid, and poly-${\beta}$-hydroxybutyric acid were not found. The guanine plus cytosine content of DNA was 52-56%. The isolate was found to grow only on methanol and monomethylamine. Growth was optimal ($t_d=2.4h$) at $35^{\circ}C$ and pH 6.5 in a mineral medium containing 0.5% (v/v) methanol, 25 mM phosphate, and 0.212% ammonium sulfate. Methanol was assimilated through the ribulose monophosphate pathway. Maximun amount of EPS was produced in cells growing at the mid-stationary growth phase at $30^{\circ}C$ in a mineral medium (PH 6.5) containing 1.0% (v/v) methanol in the CIN ratio of 54.7. Thin-layer chromatographic and high performance liquid chromatographic analysis revealed that the EPS was composed of glucose and galactose. EPS which was not treated with ethanol (Pbe) exhibited stable viscosity under various concentrations of salts and temperatures hut showed high viscosity at low pH. EPS precipitated with ethanol (Pae) was found to be more stable in viscosity than the Pbe at various salt concentrations, temperatures, and pH. The Pae also exhibited higher viscosity than the Pbe and xanthan gum. Scanning electron microscopy revealed that the lyophilized Pbe and Pae have a multi-layered structure and a structure of thick fibers, respectively.