• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.166-171
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• 2008

We cannot imagine any more the environment and energy problems are separated from our lives. The various attempts to solve these problems are made all over the world. In this study it was performed to analyze a different heating and cooling load depending on the earth-sheltering method and kind of soils by using TRNSYS 16 as the first step to establish the design guidelines for earth-sheltered architecture, one of the eco-friendly and low energy consuming building types. After performing this simulation, we found the result like this. It is the most lowest load in case of all of walls and roof being earth-sheltered. But considering of the load reduction rate, the effect of earth-sheltering the exterior vertical wall is more efficient for load reduction than the one of earth-sheltering a roof. And we got a lower thermal load in case of a lower heat conductivity of soil. Afterwards we will conduct a further study for boundary condition at earth-sheltered surface and the simulation analysis about the sensitivity variables. The final goal of this study is preparing the design guidelines for earth-sheltered architecture. so we will contribute to building energy saving.

• 대한화학회지
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• 제35권2호
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• pp.158-164
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• 1991

염기성용액 중의 수은전극에서 o-cresolphthalexon(OCP)의 전기화학적 거동을 직류, 펄스차이 폴라로그래피, 정전위 전해 및 순환 전압전류법으로 조사하였다. OCP는 NaCl 지지전해질에서 1전자 2단계 환원반응을 하였으며, 반파전위는 pH에 따라 변화하였다. 순환 전압전류법에 따라 고찰한 결과 첫번째 1전자 환원반응을 뒤에 형성된 라디칼은 이합체화 반응을 하였으며, 표준 속도상수는 $3.27{\times}10^{-2}$ cm/sec로 가역반응을 나타냈다. 두번째 환원반응은 전자전이반응에 이어 생성된 carbanion의 빠른 양성자화 첨가반응으로 비가역적 거동을 나타냈다. OCP의 농도(<$1{\times}10^{-4}$M)가 낮은 경우 흡착현상이 현저하게 일어났으며, -1.85V에서 정전위 전해시 전해시간이 증가함에 따라 OCP의 자주색은 점점 옅어져서 무색이 되었으며, 최종생성물은 전기적으로 불활성이 되었다. 따라서 OCP의 단계적인 전극반응은 ECEC 메카니즘으로 제안된다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권10호
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• pp.1580-1590
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• 2019

Objective: The aims of this study were to select one strain of Lactobacillus plantarum (L. plantarum) for a potential indigenous safe starter culture with low level antibiotic resistant and low biogenic amine production and evaluate its effect on biogenic amines reduction in Moo som. Methods: Three strains of indigenous L. plantarum starter culture (KL101, KL102, and KL103) were selected based on their safety including antibiotic resistance and decarboxylase activity, and fermentation property as compared with a commercial starter culture (L. plantarum TISIR543). Subsequently, the effect of the selected indigenous safe starter culture on biogenic amines formation during Moo som fermentation was studied. Results: KL102 and TISIR 543 were susceptible to penicillin G, tetracycline, chloramphenicol, erythromycin, gentamycin, streptomycin, vancomycin, ciprofloxacin and trimethoprim (MIC90 ranging from 0.25 to $4{\mu}g/mL$). All strains were negative amino acid-decarboxylase for lysis of biogenic amines in screening medium. For fermentation in Moo som broth, a relatively high maximum growth rate of KL102 and TISIR543 resulted in a generation time than in the other strains (p<0.05). These strain counts were constant during the end of fermentation. Similarly, KL102 or TISIR543 addition supported increases of lactic acid bacterial count and total acidity in Moo som fermentation. For biogenic amine reduction, tyramine, putrescine, histamine and spermine contents in Moo som decreased significantly by the addition KL102 during 1 d of fermentation (p<0.05). In final product, histamine, spermine and tryptamine contents in Moo som inoculated with KL102 were lower amount those with TISIR543 (p<0.05). Conclusion: KL102 was a suitable starter culture to reduce the biogenic amine formation in Moo som.

• 드라이브 ㆍ 컨트롤
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• 제18권1호
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• pp.1-8
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• 2021

This paper presents research on methods for the reduction of forklifts' noise level for the increased comfort and safety of its operator. A cooling fan with a high air volume flow rate installed in the forklift acts as an important design parameter which efficiently cools the heat exchanger system, helping to transfer internal heat from the engine room to the outdoors with both transmitted and diffracted opening noises. The cooling fan contributes significantly to both the forklift's emitted sound power and the operator room's noise level, thereby necessitating research on the forklift's reduction of acoustic power level and transmission. A noise analysis for various fan models with a biomimetic design based on eagle-wing geometry was conducted. In addition to the acoustic power generation, the aerodynamic performance of the cooling blade is also strongly influenced by the design of airfoil distribution, thereby requiring optimization. The cooling fans were fabricated and installed in the forklift in order to check the efficacy of the forklift engine's cooling, and the final version of the fan was measured for its ability to lower acoustic power level and cool the engine room. This study explains the aerodynamic and acoustic features of the designed fans with the use of BEM analysis and forklift test results.

• 가족자원경영과 정책
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• 제12권2호
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• pp.15-30
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• 2008

According to the research taken by the National Statistical Office, the fertility rate of a Korean fertile female is 1.17. This figure is the lowest in the world, and the reduction in the fertility rate over the last 30 years was the biggest in the world. It can be seen as a warning alarm about the effects of a low birth rate and a silver society. Assuming that there are several factors involved in this phenomenon, this study inquired into the attitude towards children, attitude towards nourishing children, attitude towards sex roles and the harmony between the jobs and families of married females, and examined the factors that influence the willingness to give birth. Final 581 copies of the survey questionnaire were used for analysis and the collected data were analysed by SPSS, Pearson's correlation analysis, t-test, ANOVA, and Duncan's Multiple Range Test. Three main conclusions were reached: Firstly, the value variables, such as sex-role attitudes and the preference for work or home, affect the willingness to give birth. Therefore, it can be said that one's values have a significant effect on these variables and the willingness to give birth. Secondly, both working morns and housewives have a strong tendency to give a birth if they are supported on child rearing. Finally, the employment of the married women itself can be a variable that can affect childbirth. In other words, the working hours affect employed married women so as sex-role attitudes, the preference between work and home, ideal number of children, and the income to housewives. Also, even in whole married women, the employment itself can be a major factor of the willingness to have a baby. Therefore, unemployed married women have more of a tendency to have children than employed married women.

• Archives of Hand and Microsurgery
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• 제23권4호
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• pp.248-253
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• 2018

목적: 변형-내초점 핀 고정술을 통한 골성 망치 수지의 해부학적인 직접 정복에 대한 임상적 결과를 알아보고자 한다. 방법: 2014년 3월부터 2017년 10월까지 18명의 골성 망치 수지 환자를 대상으로 K-강선을 이용하여 골편을 직접 정복하는 방법인 변형-내초점 핀 고정술을 시행하였다. 수술 후 통증, 관절 운동 범위, 방사선적인 평가를 시행하였다. 또한 골유합 시기, 기능 회복 정도, 합병증 발생률을 평가하였고, 수술 후 기능적 예후를 판정하기 위해 Crawford의 평가 기준을 이용하였다. 결과: 평균 6주(5-7주)에 방사선적 골유합을 얻었다. 전체 환자에서 평균 $2.8^{\circ}$ ($0^{\circ}-10^{\circ}$)의 신전 소실(extension loss)이 발생하였다. 모든 환자에서 관절면의 일치와 만족스러운 관절면의 재형성이 관찰되었으며, 최종 외래 추시에서 원위지간 관절의 평균 굴곡각은 $72.2^{\circ}$ ($70^{\circ}-75^{\circ}$)였다. Crawford의 평가 기준으로 아주 만족이 12명(66.7%), 만족이 6명(33.3%)이었다. 결론: 변형-내초점 핀 고정술은 골편을 직접 정복 후 고정하여 해부학적 정복을 얻는 방법으로 기존의 다른 경피적 핀 고정술들과 결합하여 적절한 적응증에 적용한다면 좋은 결과를 얻을 수 있을 것으로 기대한다.

• 한국토양비료학회지
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• 제44권1호
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• pp.22-28
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• 2011

With the increasing cultivation of acid-loving plants such as blueberries, the artificial acidification of soils is frequently required. This research was conducted to determine the application rates of elemental sulfur (S) required in the soil acidification for blueberry cultivation. Laboratory incubation experiment was conducted to acidify three arable soils (pH 6-7) of different texture to pH 4.5-5.0 by the addition of varying amounts of elemental S. All rates of elemental S addition reduced soil pH, although the efficacy of acidification was related to the application rate and soil characteristics. pH reduction was slow in sandy loam soil, and the final equilibrium pH was obtained after 60, 43, and 30 days of incubation in sandy loam, loam, and silty clay, respectively. Although the final pHs obtained after 93 days of incubation were not significantly different among the three soils, the equilibrium pH was relatively higher in soil of higher clay content in the application rates of 1.5-2.0 g S $kg^{-1}$ soil. The estimated amounts of elemental S required in lowering pH to 4.5-5.0 were 0.59-1.01, 0.67-1.03, and 0.53-0.88 g S $kg^{-1}$ for sandy loam, loam, and silty clay, respectively. The lowest estimated amount of elemental S in the acidification of silty clay soil was attributable to the low organic matter content. For clay soils containing optimum level of organic matter, the application rates of elemental S should be much higher than those values estimated in this research. Soil acidification did not significantly increase the available concentrations of Ca, Mg and K. Extractable Cu and Zn was not greatly affected by the acidification, but extractable Fe, Mn, and Al in the acidified soils were higher than those found in non-acidified soils. Such increases in solubility are attributable to the dissolution of oxides and hydroxides of the elements.

• 환경생물
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• 제17권2호
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• pp.183-190
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• 1999

The bioleaching of heavy metals from fly ash was performed by Thiobacillus thiooxidans MET isolated from the enrichment culture of an anaerobically digested sludge. The effect of solid concentrations on the efficiency of metal leaching was studied in shaken flasks. In the range of solid concentrations 20 g.L­$^1$to 100 g.L­$^1$T. thiooxidans MET oxidized S$^{0}$ to sulfate without any lag period. The final pH of slurry solution was decreased to below pH 1, and the final oxide-redox potential (ORP) was increased to over 420 mV in the solid concentrations below 100 g.L­$^1$. However, the initial lag period of 4 to 8 days was required to obtain the pH reduction and ORP increase of the slurry solutions in the range of solid concentrations 150 g.L­$^1$to 300 g.L­$^1$. The sulfur oxidation rate of T. thiooxidans MET in 20~100 g.L­$^1$solid concentrations was 0.70~0.75 g-S.L­$^1$ㆍ d­$^1$, but its sulfur oxidation activity was remarkably inhibited with increasing solid concentration over 150 g.L­$^1$. Increasing fly ash solids concentration in the range of solids concentration 20 g.L­$^1$ to 200 g.L­$^1$decreased the removal efficiency of Zn, Cu, Mn, Cr and Pb. The solubilization of heavy metals from fly ash was strongly correlated with the pH value of slurry solution. When the pH of slurry solution was reduced to 3, the solubilization process of Zn, Cu and Mn started, and their solubilization efficiency of Zn, Cu and Mn was progressively increased below pH 2. However, the solubilization process of Cr and Pb started at pH 2.5 and 2.0, respectively.

• 한국재료학회지
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• 제18권6호
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• pp.307-312
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• 2008

In this study, a new cleaning process with a low cost of ownership (CoO) was developed with ozonated DI water ($DIO_3$). An ozone concentration of 40 ppm at room temperature was used to remove organic wax film and particles. Wax residues thicker than $200\;{\AA}$ remained after only a commercial dewaxer treatment. A $DIO_3$ treatment in place of a dewaxer showed a low removal rate on a thick wax layer of $8000\;{\AA}$ due to the diffusion-limited reaction of ozone. A dewaxer was combined with a $DIO_3$ rinse to reduce the wax removal time and remove wax residue completely. Replacing DI rinse with the $DIO_3$ rinse resulted in a surface with a contact angle of less than $5^{\circ}$, which indicates no further cleaning steps would be required. The particle removal efficiency (PRE) was further improved by combining a SC-1 cleaning step with the $DIO_3$ rinsing process. A reduction in the process time was obtained by introducing $DIO_3$ cleaning with a dewaxing process.

• 생명과학회지
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• 제29권3호
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• pp.362-368
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• 2019

Pseudomonas sp. GP32가 생산하는 생물고분자 응집제 Biopol32의 실제 응용, 개발을 위하여 식품폐수, 도축폐수, 염색폐수에 대하여 응집효과를 검토하였다. 식품폐수의 경우 pH 6.0에서 70%의 화학적산소요구량(COD) 감소율과 49%의 부유고형물(SS) 제거율을 나타내었다. 도축폐수에서는 pH 4.0에서 61%의 화학적산소요구량 감소율과 91%의 부유고형물 제거율을 보였으며, 염색페수의 경우 pH 5.0에서 72%의 화학적산소요구량 감소율과 92%의 부유고형물 제거율을 보였다. 응집과정에서 형성되는 floc의 크기는 Biopol32 용액을 최종농도 20 ppm으로 첨가하였을 때 10 mm였고 이때 탈수효율은 62%였다. 생물응집제 Biopol32 첨가구와 합성응집제 PAA 첨가구에서 탈수효율이 전반적으로 가장 좋은 응집제 첨가 농도는 20 ppm으로 나타났으며, 또한 이때 자연한계함수율(78.1%)에 이르는 최단의 여과시간을 얻을 수가 있었다.