• Journal of Nutrition and Health
• /
• 제29권3호
• /
• pp.260-266
• /
• 1996

Eighteen crossbred pigs were weaned at 4 days of age and fed up to 28 days of age to examine the effect of sulfur amino acid content of three diets upon plasma taurine concentration and hepatic cysteinesulfinate decarboxylase activity. The experimental diets consisted of either whey protein (W) or partialy hydrolyzed soy protein (S) as the source of protein. 0.25% methionine was added to the S diet for the third dietary regimen (SM). Sulfur amino acid content(methionine plus cystine)of the three diets was 1.53%, 1.34% and 1.09% for the W, SM and S diet, respectively. Plasma taurine concentration from the pigs fed the three experimental diets reflected the total sulfur amino acid content of the diet. The S diet resulted in a significantly lower plasma tarrine level than the W and SM diets throughout the experiment. After three weeks, pigs fed the W diet had significantly higher plasma taurine concentration than those fed SM diet. Therfore it appears that taurine requirement of the pig depends on the sulfur amino acid contents of the diets and the conversion o sulfur amino acid to taurine seemed not to be limited by any factor when sulfur amino acid was below 1.53% of the diet. There was no significant difference between three dietary groups in hepatic cysteinesulfinate decarboxylase activity and this suggests that the reduced cysteinesulfinate decarboxylase activity due to high sulfur amino acid in the diet may not occur in the pig liver.

• Journal of Nutrition and Health
• /
• 제37권2호
• /
• pp.100-107
• /
• 2004

This study was performed to evaluate the effect of dietary protein source and sulfur amino acid content on bone metabolism in ra. Thirty male rats (body weight 145$\pm$2g) were divided into three groups. The rats in the first group were fed on casein 20% diet as animal protein source and those in the second group were fed on soy 20% diet as plant protein source. Sulfur amino acid ratio of these group was 1.07:1. The rats in the third group were fed on soy 20% diet and the sulfur amino acid were supplemented with the amount contained as much in the soy 20% diet. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks, The total body, spine, femur bone mineral density and bone mineral content were measured using Dual Energy X-ray Absorptiometry Calcium, phosphate, pyridinoline, creatinine in urine and calcium, phosphate, alkaline phosphatase, osteocalcin in serum were measured. During the experimental period, plant protein (soy protein) group had a lower urinary Ca excretion, urine pyridinoline ＆ crosslinks value and had a higher Ca efficiency in total bone and femur bone mineral density than animal protein (casein) group. There were no significant differences in serum calcium, phosphate, alkaline phosphatase and osteocalcin among the three groups of the rats. The findings from this study demonstrated that plant protein (soy protein) is beneficial of bone mineral density because it had a higher Ca efficiency in total bone and femur bone mineral density than animal protein (casein). However, the supplementation of sulfur amino acid on soy results were consistent with prior studies that dietary sulfur amino acid load had a negative effect on calcium balance. The rats fed sulfur amino acid supplementation diet increased urinary calcium excretion and decreased calcium efficiency for total and femur mineral density. Therefore, dietary protein source and sulfur amino acid content influence bone metabolism. (Korean J Nutrition 37(2): 100-107, 2004)

• 산업기술연구
• /
• 제15권
• /
• pp.175-185
• /
• 1995

Under the new environmental regulations announced by the government, utilities will have to cut their sulfur dioxide emissions by 60% from 1991 levels by the year of 1999. Sulfur dioxide emissions can be reduced prior to combustion by physical, chemical or biological coal cleaning. The new technology of high gradient magnetic separation (HGMS) offers the potential of economic separatoins of a variety of fine, weakly magnetic minerals including inorganic sulfur and many ash-forming minerals from coals. In the present paper, magnetic separation tests have been conducted on Korean anthracite and high-sulfur Chinese coal to investigate the feasibility of these techniques for reducing sulfur content from coals. In wet magnetic separation, the studied operating parameters include particle size, pH, matrix types, feed solids content, feed rate, number of cleaning stages and etc. The results shows that for wet separation, 60~70% of total sulfur was removed from coals with over 80% combustible recovery, on the other hand, for dry separation, 47.6% of total sulfur was removed from coals with 75% recovery.

• 한국작물학회지
• /
• 제38권6호
• /
• pp.499-506
• /
• 1993

콩의 함황아미노산 함량의 향상을 위한 유전육종학적 기초연구의 일환으로 서울대학교 농학과에서 유지해오고 있는 품종 및 계통과 국내 수집 계통 등 518점을 공시재료로 하여 황함량을 분석조사하고 아울러 함황단백질, 함황아미노산과의 관계를 알아보고 황함량의 유전현상과 잡종초기세대에 있어서의 황함량의 선발효과를 분석조사하였다. 종실중의 황함량은 재배중은 0.20～0.45%의 변리로 평균함량은 0.33%였고 국내 수집 야생콩(30계통)은 0.19～0.62%의 변이로 평균 0.35%였다. 종실중의 황함량은 함황단백질 및 함황아미노산과 각각 r=0.924$^{**}$, r=0.974$^{**}$의 높은 상관관계를 보였고 종실 특성 및 생육 특성 구분에 의한 품종 또는 계통군의 황함량은 성숙이 늦은 것, 종피에 피분이 존해하는 것, 푸른 자엽색인 것들의 황함량평균이 높았으며 종실중의 황함량과 당함량 및 100립증과는 각각 r=-0.312$^{**}$, r=-0.383$^{**}$의 유의상관을 나타냈다. 종실중 황함량의 유전현상은 양적형질의 유전현상을 나타냈으며 황함량을 높이는 상가적효과가 우성효과보다 큰 것으로 나타났고 종실중의 황함량을 높게하는 유전자와 낮게하는 유전자의 분포비율은 비슷한 것으로 추정되었다. 그리고 추정된 협의의 유전력과 광의의 유전력은 0.75(Hn), 0.88(Hb)로 나타났고 선발효율은 고, 저 양방향으로의 조기세대 선발에 의해 높은 방향의 선발에서 14.7～18.8%가 높아졌고, 낮은 방향의 선발에서 8.8～15.6%가 저하되었으며 모든 경우 유의하게 선발효과가 있었다.

• 미생물학회지
• /
• 제7권2호
• /
• pp.57-62
• /
• 1969

The experiments attempted to basic studies on the atmospheric dioxide in Korea and on the elimination of sulfur in oil Thiobacilli in order to control of atmospheric sulfur dioxide. The results of experiments are following as : 1) Content of atmospheric sulfur dioxide in industrial zone which used kerosene for fuel was 0.092 ppm(average) and 0.16ppm(maximum). 2) Content of sulfur dioxide at room air which used briquet for stove fire was 0.44ppm (average) adn 0.50 pp,(maximum). 3) Thirteen strains of thiobacilli were isolated from Korean soil and sewage and they were identified with T. thiooxidans (5strains), T. thioparus(3strains), T.ferrooxidans 3 man's observation and the description in Bergey's manual. 4) Two promising strains, one of T. thiooxidans and one of T. ferooxidans. were selected for elimieation of in kerosene.

• 한국대기환경학회지
• /
• 제14권4호
• /
• pp.387-392
• /
• 1998

Recently, among after-treatment devices which have high possibility of utility, diesel oxidation catalyst (DOC) is concerned over the world. DOC oxidizes pollutants by means of activate-reaction during by -passing in the catalyst, in doing so, conversion efficiency of PM, CO and HC is high, and this device does not have an effect on engine performance because back pressure is not nearly increased. But, as a small amount of sulfur content in fuel is oxidized, it makes sulfate, which is absorbed on the surface of catalyst. So, in this study, the experiment is carried out by means of using ordinary fuel (0.1wt%) and low sulfur fuel (0.05wt%) with DOC, and the emission gas of diesel engine is measured.

• 한국환경농학회지
• /
• 제14권2호
• /
• pp.144-154
• /
• 1995

울산지역내 23개의 배나무 조사구를 선정하여 조사장소의 재배환경과 배나무잎의 수용성 황 함량, 광합성 속도 및 가시피해도지수를 측정, 분석하여 울산지역의 대기오염 평가를 시도할 결과는 다음과 같다. 1. 배나무잎의 평균 수용성 황 함량은 0.201%였으며, 오염지역 조사구는 $0.220{\sim}0.496%$로 높았다. 또한 오염배출원을 중심으로 거리가 멀어짐에 따라 수용성 황 함량은 감소되었다. 2. 배나무의 광합성 속도는 수용성 황 함량이 축적됨에 따라 감소되었고, 오염배출원을 중심으로 반경 5km까지는 거리가 멀어짐에 따라 광합성 속도가 증가되었다. 3. 1993년 배나무의 가시피해도를 산정한 결과 오염배출원으로부터 5km 이내에서는 60% 이상의 피해율을 나타냈으며, 피해도지수 각 항목간에는 고도의 정의 상관이 인정되었다. 또한 1988년과 비교해 보면, 1988년에는 여천동과 야음동을 중심으로 피해율이 높았으나 1993년에는 용잠동과 부곡동을 중심으로 피해의 중심지가 이동하였다. 4. 수용성 황 함량과 피해도지수, 수용성 황 함량과 광합성속도 간에는 고도의 상관이 인정되어 배나무를 이용한 대기중 $SO_2$평가에 활용될 수 있는 가능성을 보였다.

• Tribology and Lubricants
• /
• 제31권3호
• /
• pp.86-94
• /
• 2015

We perform lacquer formation experiments with various combinations of marine fuel oils and lubricant oils. We also investigate the influences of base number (BN) in lubricant oil and sulfur content in fuel oil. A dissolution test with 10% dilute sulfuric acid and pull-off force test are accomplished to distinguish whether the residual layers are lacquering or not. The lacquering layers are dissolved by dilute sulfuric acid and have a strong pull-off force. Moreover, the calcium content detected in the residual layers is compared by energy dispersive x-ray spectroscopy (EDS). More calcium is detected in the lacquer layers than in other residual layers. Distillate fuels containing low sulfur levels are more prone to lacquering when mixed with lubricant oil with a high BN. On the other hand, residual fuels with a high sulfur content do not form lacquer. We investigate the effect of mixture volume ratio. The mixture with higher fuel oil content is more prone to generate lacquer. These experiments indicate that a lubricant with an appropriate BN should be used to prevent lacquer forming on the surfaces such as cylinder liners depending on the sulfur content of fuel oil.

• Elastomers and Composites
• /
• 제56권1호
• /
• pp.32-42
• /
• 2021

The vulcanizate structure of silica-filled compounds is affected by the filler-rubber interaction (FRI) due to the silica-rubber coupling reaction and the chemical crosslink density (CCD) of the matrix rubber. In this study, the vulcanizate structure changes of silica-filled compounds according to the silane and sulfur variation were quantitatively analyzed using the Flory-Rehner and Kraus equations. In efficiency vulcanization (EV) conditions with low sulfur content, FRI increased when the bis-[3-(triethoxysilyl)propyl]tetrasulfide (TESPT) content increased, and the CCD clearly decreased. By contrast, in semi-EV conditions with high sulfur content, as TESPT content increased, the FRI increased the same way EV conditions, but the CCD was unchanged. Based on these results, it was confirmed that FRI of the silica-filled compounds increased as TESPT content increased, but CCD decreased or retained similar values according to the vulcanization system, indicating that the formation reaction of FRI was preferred over CCD.

• 한국자동차공학회논문집
• /
• 제6권3호
• /
• pp.138-142
• /
• 1998

Among aftertreatment devices which reduce exhaust gas of diesel engine, diesel oxidation catalyst(DOC) with high reduction efficiency for gaseous matter and particulate matter is now being studied actively. In this study, an experiment was conducted to analyze the effects of low sulfur diesel fuel in heavy duty diesel engine equipped with DOC. We tested to estimate change of engine performance for the low and high sulfur diesel fuels in a 11,000cc diesel engine equipped with DOC. We conducted test to estimate the reduction efficiency of exhaust gas in D-13 mode of heavy duty diesel regulation mode and in smoke opacity mode for two samples of high sulfur content (0.2%) and low sulfur content(0.05%)