• 오토저널
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• 제14권6호
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• pp.74-80
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• 1992

The purpose of this study is to improve the performance of gasoline engine. Combustion-characteristics orignated from supplying cylinder with fuel-air mixture which was formed by the rise of oxygen-concentration in air with oxygen-enriching membrane have been investigated. The results showed that the poor-limit of oxygen-concentration was increased by shortening combustion-duration because the rise of oxygen-concentration in fuel-air mixture resulted in the promotion of combustion-velocity. Also, the generation of large output of power was expected from combustion in proportion as the amount of oxygen was increased.

• 한국의류산업학회지
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• 제6권3호
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• pp.393-398
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• 2004

This research offers recycling method of NaOH from mercerizing process of cotton fabric. The measuring system of NaOH concentration was designed for the mercerizing process and tested for various conditions which can be occurred in factory. The accuracy of the system was varied as the testing condition was changed. As the concentration of sulfuric acid used for titrating NaOH decreased, the accuracy of measuring system increased. The concentration of NaOH for waste water collected from mercerizing process was measured by 5.2%. As the ratio of newly mixed NaOH increased, moisture regain. water absorbency and whiteness of the specimen increased. The bending rigidity(B) and shear rigidity(G) decreased, as the ratio of newly mixed NaOH increased.

• 멤브레인
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• 제14권3호
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• pp.192-200
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• 2004

본 연구에서는 유기질막에 비해 안정성이 우수하고 사용수명이 긴 세라믹 막을 이용하여 혐기성 Lactobacillus 균주의 농축에 관해서 연구하였다. Cell harvesting (CH)에 영향을 주는 인자로 막투과 압력, 온도, 선속도 등에 대해 조사하였으며 세라믹 막을 이용하여 농축율 변화에 따른 플럭스와 TMP (transmembrane pressure)의 변화, 일정 VCF(volumetric concentration factor)에서 TMP변화 등의 최적조건에 관해 알아보았다. 그 결과 플럭스는 TMP, 선속도, VCF가 증가함에 따라 투과수량도 증가함을 알 수 있었다. 온도가 증가할수록 점도에 의해 초기 플럭스도 증가하지만 시간이 경과함에 따라 막 표면의 겔층의 형성으로 온도의 영향은 미미하였다. 또한 농축비 이하의 일정한 VCF에서 운전할 경우 플럭스가 안정적임을 알 수 있었다. 선속도 5 m/s, 공급액의 온도 $37^{\circ}C$, TMP 1 bar에서 6∼8 h 운전할 경우 PS 406 원액의 생균수는 4.9{\times}10^9$으로 약 8배 농축됨을 알 수 있었다.

• 한국환경과학회지
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• 제19권8호
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• pp.1013-1023
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• 2010

The purpose of this study was to analyze the characteristics of spacio-temporal variation for $PM_{10}$ and $PM_{2.5}$ concentration in Busan. $PM_{10}$ concentration has been reduced for the past three year and exceeded $50\;{\mu}g/m^3$ of the national standard for $PM_{10}$. $PM_{2.5}$ concentration showed gradual decrease or stagnant trends and exceeded the U.S. EPA standard. Seasonal analysis of $PM_{10}$ and $PM_{2.5}$ suggested spring>winter>fall>summer(by Asian dust) and winter>spring>summerenlifall(by anthropogenic effect) in the order of high concentration, respectively. Characterization of diurnal variations suggests that $PM_{10}$ levels at all the three sites consistently exhibited a peak at 1000LST and $PM_{2.5}$ at Jangrimdong experienced the typical $PM_{2.5}$ diurnal trends such that a peak was observed in the morning and the lowest level at 1400LST. In the case of seasonal trends, the $PM_{2.5}/PM_{10}$ ratio was in the order of summer>winter>fall>spring at all the study sites, with a note that spring bears the lowest concentration. During AD events, $PM_{10}$ concentration exhibited the highest level at Jangrimdong and the lowest level at Joadong. And $PM_{2.5}/PM_{10}$ ratio in AD was 0.16~0.28.

• 한국자원식물학회지
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• 제10권3호
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• pp.221-226
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• 1997

Improvement of seed protein quality might be an essential issus in soybean and would give more profit directly to both farmers and users. This study was carried out to investigate the effects of reduced-S form(s) on seed storage protein components in soybean during seed filling stages. The reduced-S forms during seed fill were sodium thiosulfate, sodium sulfite, sodium sulfide, thioaceteat, $\beta$-mercaptoethanol, thiourea, thiamine-HCI, L-cysteine, L-cystine, and L-methionine. Seed storage protein concentration did not appear to be affected by any reduced-S forms. However, glycinin and $\beta$-conglycinin concentration seemed to be changed greatly by L-methionine. This resulted in the increase in the 11S/7S ratio(3.58). Among the $\beta$-conglycinin, $\beta$-subunit was not accumulated at all. $\alpha$-subunit concentration appeared to be decreased and $\alpha'$-subunit concentration was not altered in comparison with sulfate control. Also, $\beta$-conglycine concentration, especially $\beta$-subunit concentration, tended to be decreased with L-cystine treatment, resulting in an increase in the 11S/7S ratio(1.83). The glycinin concentration tended to be increased at the expense of the decrease in the $\beta$-conglycinin concentration. Therefore, it is suggested that enhancing soybean protein quality would be achieved by improving metabolic pathways of S assimilation in soybean plants during seed filling period under sulfate-sufficient condition.

• 한국환경보건학회지
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• 제17권2호
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• pp.127-139
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• 1991

Four group(Control I II, Treatment I II ) of Rats, each consisting of 10 rats, were studied Methylmercury Chloride MMc was orally given to Sprague-Dawley male at does of 10mg/kg (5 mg/kg $\cdot$ day), 10mg/kg after two weeks. This study was designed to investigate the distribution, the difference and the ratio of organic mercury, total mercury, zinc and copper in tissue, in each others group. The result were as follows: 1. There was no significantly difference in the body weight between two groups( p > 0.05). 2. There was significantly difference in the distribution of zinc concentration in liver, kidndey, blood, spleen between control I and treatment I, and in blood, spleen between control II and treatment II (P < 0.05). 3. There was significantly difference in the distribution of copper concentration in kidney, blood between control I and treatment I, and in spleen brain between control II and treatment II. 4. The ratio of zinc concentration in treatment/control was high at spleen. 5. The ratio of methylmercury/totalmercury was high at spleen.

• 오토저널
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• 제7권4호
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• pp.49-56
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• 1985

This study consists of instrumenting and running tests on variable compression engines and measuring the following combustion characterics: (a)flame speed, (b) emission and (c)performance parameter such as power and economy. The results were as follows: 1) The phase separation diagram of substitute fuels were obtained from phase separation experiment. 2) The flame propagation speed of substitute fuels were higher than gasoline and increased with increasing methanol weight percent of substitute fuels. 3) BEMP of substitute fuels was slightly less than that of gasoline but in the range of small weight percent, BEMP was compatible to gasoline. 4) Concentration of NOx decreased significantly with delaying spark advancing time. Also, it decreased for rich equivalence ratio but increased with high compression ratio. In general, NOx concentration was much lower than that of gasoline. 5) Concentration of HC and CO increased for rich equivalence ratio. Also it was lower than that of gasoline.

• Journal of Microbiology and Biotechnology
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• 제4권3호
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• pp.191-194
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• 1994

Acetoin and ammonia, the precursors of tetramethylpyrazine (TMP) having "nutty " or "roasted" flavors, were produced by cultivating Lactococcus lactis ssp. lactis biovar. diacetilactis FC1. The effects of the volume concentration ratio (VCR) of cell-free medium on the formation of TMP were investigated using a rotary evaporator at $70^{\circ}C than at 80^{\circ}C$. As the VCR increased, the formation of TMP and the conversion ratio of acetoin to TMP increased. More TMP were formed at $70^{\circ}C than at 80^{\circ}C$. As the VCR increased, the concentration of acetoin decreased implying the formation of TMP from acetoin and ammonia.

• Smart Structures and Systems
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• 제17권5호
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• pp.725-742
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• 2016

This paper is focused on stiffness ratio effect and a new method to specify the best pattern of piezoelectric patches placement around a hole in a plate under tension to reduce the stress concentration factor. To investigate the stiffness ratio effect, some different values greater and less than unity are considered. Then a python code is developed by using particle swarm optimization algorithm to specify the best locations of piezoelectric actuators around the hole for each stiffness ratio. The results show that, there is a line called "reference line" for each plate with a hole under tension, which can guide the location of actuator patches in plate to have the maximum stress concentration reduction. The reference line also specifies that actuators should be located horizontally or vertically. This reference line is located at an angle of about 65 degrees from the stress line in plate. Finally two experimental tests for two different locations of the patches with various voltages are carried out for validation of the results.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 제7회 압연 심포지엄
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• pp.13-16
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• 2009

In order to investigate the effects of geometry factors such as a roil diameter ratio and backup roll crown of the stress concentration factor on the edge of backup roil end, 3-dimensional FEM analyses of stress at the contact of backup roll and work roll assembled in a 4-high strip mill were carried out, It was made clear that the peak stress at the edge is about 2 to 3 times of that at the longitudinal center of the roll barrel and the peak stress proportionally increase with decreasing the ratio of backup roll diameter to work roll diameter Furthermore a crowning on the backup roll is effective to decrease the maximum edge stress.