• International Journal of Concrete Structures and Materials
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• 제4권1호
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• pp.55-62
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• 2010

The performance evaluation of a sodium lauryl sulfate to qualify as a foaming agent is presented in this paper. When new surfactants are used a systematic study of production parameters on the foam characteristics needs to be undertaken unlike proprietary foaming agents and foam generator for which manufacturer has predefined the parameters. The relative influence of the foam parameters and optimization of factors were carried out through a systematic experiment design. The foam production parameters namely foam generation pressure and dilution ratio of foaming agents are observed to have significant effect on all foam characteristics with the exception of foam output rate on which only foam generation pressure has influence. The foam with good initial foam density need not necessarily be stable foam. The optimum levels of foam production parameters are determined for the surfactant Sodium lauryl sulfate which can be used to produce stable foam for foam concrete production.

• 한국환경보건학회지
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• 제24권3호
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• pp.54-62
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• 1998

20 bacterial strains capable of growing on phenol minimal medium were isolated from soil and wastewater by the enrichment culture technique, and among them, one isolate which was the best in the cell growth was selected and identified as Bacillus sp. SH3 by its characteristics. Strain SH3 could grow with phenol as the sole carbon source up to 15 mM, but did not grow in minimal medium containing above 20 mM of phenol. The optimal conditions of temperature and initial pH for growth and phenol degradation were 30$^{\circ}$C and 7.5, respectively. This strain could grow on various aromatic compounds such as catechol, protocatechuic acid, gentisic acid, o-, m-, p-cresol, benzoic acid, p-hydroxybenzoic acid, anthranilic acid, phenyl acetate and pentachlorophenol, and the growth-limiting log P value of strain SH3 on organic solvents was 3.1. In batch culture, strain SH3 degraded 97% of 10 mM phenol in 48 hours. In continuous culture under the conditions of 20 mM of influent phenol concentration and 0.050 hr$^{-1}$ of dilution rate, the treatment rate of phenol was 94%.

• 물과 미래
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• 제20권4호
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• pp.279-284
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• 1987

해양방류구에서 연직밀도구배가 있고, 임의의 수류의 방향과 속도를 가지고 흐르는 주변수중으로 방류되는 폐수의 초기 최소 희석도와 최종상승고를 예측하는 개선된 수학적 모형을 제시하였다. 밀도구배가 없는 균일한 수중에서 선분플륨의 방류실험을 통하여 얻은 결과를 이용하여 선형밀도구배를 가진 수중으로 방류되는 경우에 대한 해가 유도되었다. 유속, 유향, 밀도의 성층화 및 노즐의 형태에 대한 영향이 고찰되었으며 계산결과는 실험치와 비교되었다.

• 대한의생명과학회지
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• 제11권1호
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• pp.85-88
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• 2005

Hemoglobin is oxygen carrier protein within erythrocyte in blood. Apoprotein of this, globin, is synthesized in the cytosol but it's cofactor, heme, is synthesized in the mitochondria. It has not been known very well how globin receives the heme from mitochondria and folds to hemoglobin. In this folding process, the initial structure of globin seems to be very important. A small volume of globin at acid pH was added rapidly into the bulk of an egg phosphatidylcholine $60\%$ liposome, containing hemins, at neutral pH according to the Rapid Dilution method. It was observed that an acid-induced unfolding structure of globin is initially needed to receive hemins from the lipid bilayer of liposomes. Also, this conclusion was confirmed with the absorption spectrum of the refolded globin separated by centrifugation.

• Journal of Microbiology and Biotechnology
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• 제3권3호
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• pp.204-208
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• 1993

A fully automatic image analysis method was applied to obtain detailed data on morphological parameters of a glucoamylase fermentation broth with Aspergillus niger No. PFST-38. a mutant strain for glucoamylase hyperproducer. In the initial stage of fermentation. there was an increase in hyphal length. whereas at the end of the fermentation a decrease in hyphal length and increase in hyphal thickness were observed. The percentage of clumps declined with dilution and the influence of shear stress upon hyphal length was negligible. It was found that the slower the decrease in the main hyphal length and the number of tips with the fermentation time. the higher the glucoamylase production rate was recorded. The production rate of glucoamylase was closely related to the increase in the hyphal thickness.

• KSBB Journal
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• 제14권6호
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• pp.742-746
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• 1999

새로운 형태의 내부조사형 광생물반응기에서 Chlorella sp. HA-1의 이산화탄소 고정화 특성을 살펴보았다. 높은 이산화탄소 농도에서 균체를 적응시켜 10%와 20%(v/v) 이산화탄소 농도 모두에서 내성을 가지도록 하였다. 그리고 조도, 초기균체농도, pH 등을 조절하여 이산화탄소 고정화양, 372 $gCO_2/m^2{\cdot}day$을 얻었다. 또한 장시간 동안 지속적으로 배출되는 이산화탄소를 제거하기 위한 운전 방법으로 반연속식 배양방법을 사용하여 희석비를 0.1씩 증가시켰을 때 각 단계마다 균체성장속도를 일정하게 유지하는 결과를 얻었다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권10호
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• pp.1475-1481
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• 2002

The study was conducted to evaluate the effect of early feed restriction on growth, fat accumulation and meat composition in unsexed broiler chickens. In experiment 1, three hundred and fifty one-day-old broiler chicks were divided into 7 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group and the other six groups were fed 25% ad libitum (25% multiplied by amount of feed intake of ad libitum chicks at the previous day) for 4 or 6 days, 50% ad libitum for 4 or 6 days, and 75% ad libitum for 4 or 6 days. In experiment 2, five hundred broiler chicks were divided into 10 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group. Three initial age at which broilers were restricted (2, 4 or 6 days of age) and three type of feed restriction (physical restriction, meal feeding and diet dilution) ($3{\times}3$) were examined. They were restricted feeding for 6 days. Experimental results showed that broilers fed 25% ad libitum for 4-6 days tended to reduce leg meat fat with lower abdominal fat (p<0.05) (experiment 1). Breast meat fat was significantly higher in restricted broilers (p<0.01). Plasma triglyceride was higher in broilers fed 75% ad libitum for 4-6 days. In experiment 2, abdominal fat was lower in restricted broilers (p<0.05). Breast meat fat was significantly higher (p<0.01), whereas leg meat fat was significantly lower (p<0.05) in restricted broilers. Plasma triglyceride was significantly higher in physical feed restriction for 4 days, meal feeding for 4 days and diet dilution for 6 days (p<0.05). In conclusion, to reduce fat accumulation in abdomen and leg meat, broilers should be fed 25% ad libitum for 6 days started at 4 days, or subjected to meal feeding (6 hours per day for 6 days) started at 6 days.

• Asian-Australasian Journal of Animal Sciences
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• 제15권9호
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• pp.1319-1325
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• 2002

Two experiments were conducted to evaluate the effect of early feed restriction on growth, feed conversion ratio (FCR) and mortality in unsexed broiler chickens. In Experiment 1, 350 one-day-old broiler chickens were divided into 7 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group and the other six groups were fed 25% ad libitum (25% multiplied by amount of feed intake of ad libitum chickens at the previous day) for 4 or 6 days, 50% ad libitum for 4 or 6 days, and 75% ad libitum for 4 or 6 days. In experiment 2, 500 broiler chickens were divided into 10 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group. Three ages of feed restriction initial timing (2, 4 or 6 days of age) and three types of feed restriction (physical restriction, meal feeding and diet dilution) were used ($3{\times}3$) in both experiments. They were feed-restricted for 6 days. Results showed that restricted broilers exhibited compensatory growth in both experiments except for diet dilution groups. In both experiments, FCR of restricted broilers was higher, whereas feed intake of them was lower during restriction period. FCR of restricted broilers was lower upon refeeding. Mortality was inconsistently affected by early feed restriction. Leg abnormality was lower in restricted broilers in both experiments. Level of feed restriction significantly influenced body weight, FCR and feed intake of restricted broilers (p<0.05), but duration of feed restriction had no effect. Type of restriction significantly affected body weight, feed intake and FCR (p<0.05). It appeared that to achieve the best result (complete compensatory growth and better FCR), broilers should be restricted at 25% ad libitum for 6 days (Experiment 1). Meal feeding started at 2 days of age would show the best performance (Experiment 2).

• 한국대기환경학회지
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• 제30권2호
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• pp.95-109
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• 2014

In this study, the concentration of odorants released from albumin (EA) and yolk (EY) portions of boiled egg samples were determined as a function of storage time. The concentrations were measured at storage days of 0, 1, 3, 6, and 9 under room temperature. As such, odorants produced during both fresh and decay conditions were measured through time. A total of 19 compounds were selected as the main target odorants along with 12 reference compounds. GC-MS (for VOC) and GC-PFPD system (for sulfur gases) equipped with thermal desorption (TD) system were employed for odorant analysis in this work. The initial concentrations measured from the chamber system were converted into flux terms ($ng{\cdot}g^{-1}{\cdot}min^{-1}$). The EA showed the highest concentration of $H_2S$ (234 $ng{\cdot}g^{-1}{\cdot}min^{-1}$) at EA-0, and the concentrations of AT (Acetone) was also seen clearly in the range of 11.7 (EA-0) to 58.6 $ng{\cdot}g^{-1}{\cdot}min^{-1}$ (EA-9). The EY showed similar patterns. EtAl (Ethyl alcohol) increased 9.47 (EA-1) to 96.7 $ng{\cdot}g^{-1}{\cdot}min^{-1}$ (EA-9) in EA samples. Ketone, alcohol, sulfur groups generally exhibited high concentrations compared to other odorants. These data were also compared in relation to olfactometry related dilution-to-threshold (D/T) ratio by air dilution sensory (ADS) test and sum of odor intensity (SOI).

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.461-465
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• 2005

Characteristics of biological $CO_2$ fixation by Chlorella sp. HA-1 were investigated in a semi-continuous and series reactor system using an internally illuminated photobioreactor to overcome shortcomings of physicochemical technologies such as adsorption and membrane separation. High $CO_2$ fixation rate was achieved in the semi-continuous reactor system, in which the dilution ratios of the culture medium were controlled. The average $CO_2$ fixation rate was maintained almost constantly when the dilution ratio increased by 0.1 increment from the initial value of 0.5. The total removal efficiency of $CO_2$ was enhanced by employing a series reactor system. The average $CO_2$ fixation rate increased until 4.013 g $CO_2\;day^{-1}$ in a series operation of four reactors, compared to 0.986 g $CO_2\;day^{-1}$ in a batch operation mode. The total $CO_2$ fixation rate was proportional to the number of reactors used in the series reactor system. In the series reactor system of semi-continuous operation, a large amount of $CO_2$ was removed continuously for 30 days. These results showed that the present reactor systems are efficient and economically feasible for a biological $CO_2$ fixation.