• 분석과학
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• 제35권3호
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• pp.129-135
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• 2022

본 연구는 alumina, leucine, alumina와 leucine을 9:1로 혼합한 분말(이하 Al-Leu (9:1)), alumina와 leucine을 5:1로 혼합한 분말(이하 Al-Leu (5:1)), alumina와 sodium lactate를 5:1로 혼합한 분말(이하 Al-Lac (5:1))을 자연상태 시료지문을 남긴 후 1, 7, 14, 30일로 노화시킨 잠재지문에 전처리한 후 cyanoacrylate fuming(이하 CA 훈증법)으로 현출 증강을 시도하였다. 전체적으로 미처리한 후 CA 훈증한 잠재지문보다 alumina, leucine, Al-Leu (9:1), Al-Leu (5:1), Al-Lac (5:1) 분말로 전처리한 잠재지문의 면적값과 특징점 개수가 향상되었다. 따라서 5종류의 개시제가 CA 훈증 시 현출 증강을 향상시키는 것을 확인하였다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.811-813
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• 2008

To see the effect of magnesium on adhesion to natural zeolites, a series of batch tests were performed in this research. Mixed bacteria were sampled from the digestion tank at a local sewage treatment plant in Seoul. Magnesium-zeolites were synthesized by mixing natural zeolites with 0.096 M, 0.24 M, and 0.48 M of MgCl2 solution. For comparison, manganese and trivalent ferric zeolites were also prepared. Two grams of 0.2 mm $\sim$ 0.3 mm sized zeolites(non-treated, Mg, Mn and Fe(III) treated zeolites) and 20 mL of water were mixed in a Corex 25 mL tube. Five milliliters of culture solution including bacteria was added to the tube. The tubes were equilibrated in a shaking incubator at mesophilic temperature $(30{\pm}2^{\circ}C)$. The bacterial concentrations were measured with a Microluminometer (New Horizons 3550i) and total organic carbon (TOC) spectrophotometer (Multi NC-3100).

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.440-444
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• 2003

본 연구에서는 난분해성 물질인 액상의 TCE가 영가철 표면에서 반응시 완전히 분해가 되지 않은 상태에서 생성되어지는 부산물인 Cis-DCE와 VC의 톨루엔 분해균주에 의한 처리 가능성을 회분식 실험으로 관찰하였다. 각각 2ppm의 Cis-DCE와 VC에 톨루엔 균주를 주입한 결과 1차기질로 톨루엔을 사용하고 그후에 Cis-DCE와 VC를 제거 하는 것으로 나타났다. 또한 동시에 주입시 1차기질로 톨루엔을 사용하는 것은 동일하나 VC를 먼저 사용하고 그후에 Cis-DCE를 제거하며 제거 속도 또한 줄여드는 것으로 나타났다.

• 한국환경보건학회지
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• 제20권4호
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• pp.36-44
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• 1994

A study was carried out in order to investigate the removal efficiencies and removal characteristics of heaw metals such as Pb, Cd, Cr, Cu in raw water by one of conventional water treatment processes. The coagulants used in this study were Alum and PAC. Three kinds of water samples were provided: kaolin water, kaolin water mixed with humic acid and raw water from Han River mixed with suspended matter deposited on raw water inlet pipe. Heaw metals were added to the water samples with their respective turbidity, and jar tests were performed. In the results from heaw metal removal studies, lead might be adsorbed or exchanged on the particle surface (SS) rather than react with organic matter added. Cadmium was affected on the dissolved organic matter. Chromium was affected by the both dissolved organic matter and SS concentration, and the restabilization and the enmeshment appeared at moderate (50~80 NTU) and high (100 NTU) turbidity as defined in this experimenL The removal efficiency of copper was relatively little affected by the dissolved organic matter but by SS concentration in comparison with other heavy metals. In these studies as to the raw water turbidities and concentration of heaw metals, it is proved out that the removal efficiency on heaw metals in both cases of PAC and Alum as coagulants was not significantly different.

• 한국환경과학회지
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• 제26권8호
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• pp.967-976
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• 2017

In this study, the effect of probiotic supplementation on growth performance, blood metabolites, and meat quality of Hanwoo steer was investigated. A total of 32 Hanwoo steers (15-17 months, average body weight $462{\pm}37.9kg$) were randomly allotted to 4 dietary treatments (0, 0.5, 1.0, and 1.5% mixed probiotics), with four Hanwoo steers per pen (two replicates per treatments), and reared for 12 months. There were no differences among treatments in growth performance of Hanwoo steer (P>0.05); however, feed intake decreased linearly with increasing levels of mixed probiotics. Growth hormone and Blood Urea Nitrogen (BUN) levels responded linearly with increasing levels of dietary mixed probiotics (P<0.05), but not insulin and blood glucose did not. In particular, total cholesterol was significantly lower for the 1% mixed probiotic treatment in comparison with that of the other treatments (P<0.05). The pH, Thiobarbituric Acid Reactive Substances (TBARS), cooking loss, and meat color were influenced by increasing levels of mixed probiotics (P<0.05), but the carcass characteristics and shear force were not. Regarding sensory evaluation, the addition of mixed probiotics resulted in significant difference in meat color, tenderness, aroma, off-flavor, juiciness, and marbling score, but not in overall acceptability. In addition, fatty acid profiles indicated no differences between control and mixed probiotic treatments. In conclusion, mixed probiotic treatment at 1% levels can enhance consumer preferences possibly by reducing cholesterol and TBARS.

• Asian-Australasian Journal of Animal Sciences
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• 제14권4호
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• pp.501-506
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• 2001

This experiment was conducted to evaluate the effects of supplemental unsaturated fatty acids (UFA) on fermentation characteristics, especially on gas production, cellulose degradation and volatile fatty acid (VFA) concentration by mixed ruminal microorganisms. In order to attain this objective, unsaturated fatty acids including oleic acid (C 18:1), linoleic acid (C18:2) and arachidonic acid (C22:4) were added at varying level. Mixed ruminal microbes used in this experiment were obtained from the rumen of a cannulated Holstein cow. Medium pH values after 7 d incubation were significantly affected by type and level of unsaturated fatty acids (p<0.01). All of UFA inhibited total gas production, and especially treatment of arachidonic acid at the levels of 0.01% gave the lowest gas. production after 7 d incubation (p<0.01). Comparison of the population of protozoa revealed that UFA did not have any significant effect on the total protozoa number. The addition of UFA did not effect dry matter degradation. Volatile fatty acid (VFA) composition of the culture was influenced little by UFA, although the considerable amount of iso-type VFA were detected in UFA supplemented incubations. The ratio of acetic acids to propionic acids, however, was lower than control in all the treatments after 7 d incubation (p<0.01).

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.229-241
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• 2008

In order to investigate stabilization effect on As-contaminated soils treated by zero-valent iron(ZVI) and industrial by-products, batch tests and column tests were carried out with As-contaminated soils collected from farmland around the abandoned mine site. In batch tests, ZVI and industrial by-products(blast furnace slag, steel refining slag and oyster shell powder) were used as treatment materials to reduce As. Industrial by-products were mixed with As-contaminated soils, in the ratio of 1%, 3%, 5% and 7% on the weight base of dried soil. After incubation, all samples showed the reduction of As concentration and it was expected that ZVI and steel refining slag were effective treatment materials to remove As among treatment materials used in batch test. In column tests, columns were made by acrylic with the dimension of diameter=10cm, height=100cm, thickness=1cm and these columns were filled with untreated soils and treated soils mixed with ZVI and steel refining slag(mixing ratio=3%). Distilled water was discharged into the columns with the velocity of 1 pore-volume/day. During test, pH, EC, Eh and As concentration were measured in the regular term(1 pore-volume). As a result, ZVI and steel refining slag were shown 93%, 62% reduction of As concentration respectively by comparison with untreated soils. Therefore, if ZVI and steel refining slag are used as treatment materials in As-contaminated soils, it is expected that the As concentration in soils is reduced effectively.

• 한국수처리학회지
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• 제26권6호
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• pp.53-59
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• 2018

Water pollution is drastically increasing day by day, because of the enhancement in use of livestock, urban sewage detergents and fertilizers. Moreover increase in concentration of phosphorous and nitrogen contained in sewage, leads to green tide problem in the rivers and causes marine pollution. For this problem to solve, several technologies are being researched and developed. Among them, this experiment is a study on Bench-scale STP based on internationally certified sewage treatment equipment by MEPC. 227(64) of IMO. The purpose of this study is to compare the biological treatment efficiency of phosphorus of Bench-scale STP. The ratio of C : N : P was set to 10 : 5 : 3 and 10 : 3 : 1 as the operating conditions. And the operation cycle was set to anoxic(mixed) 70 min - aeration 50 min (70-50), anoxic(mixed) 90 min - aeration 60 min (90-60). As a result, the phosphorous treatment efficiency was 88% at average, and the treatment efficiency was steady at 90-60 better than 70-50. The efficiency of the bench-scale STP has been verified through this experiment and additional experiments are required to derive the optimal operating conditions.

• 한국환경과학회지
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• 제24권4호
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• pp.549-554
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• 2015

This study was conducted to determine the effects of mixed Korean red ginseng marc with aluminum sulfate on gas concentration and volatile fatty acid (VFA) in poultry litter during 4 weeks in terms of livestock and environment managements. A total of 240 broiler chicks were randomly allocated to four treatments in four replications and 15 birds per replicate. The four treatments was mixed to rice hull under each pen at 0, 10 g or 20 g red ginseng marc + 90g aluminum sulfate, and 100g aluminum sulfate per kg poultry litter (rice hulls). Carbon dioxide, methane, acetic acid, and propionic acids were measured weekly. The results that could be available include: First, during the experimental period, carbon dioxide emissions were not remarkably different among treatments. Second, no differences were observed among treatments in methane emissions at 2 weeks through 4 weeks, but at 1 week, the reduction in methane emissions was in following order: 100 g aluminum sulfate > 20 g red ginseng marc + 90 g aluminum sulfate > 10 g red ginseng marc + 90 g aluminum sulfate > control. Third, in spite of statistically differences, treatment with 10 g or 20 g red ginseng marc + 90g aluminum sulfate, and 100g aluminum sulfate reduced acetic acid and propionic acid as a function of time, except acetic acid in aluminum sulfate treatment at 2 and 4 weeks. In conclusion, the results indicated that like aluminum sulfate, using 10 g or 20 g red ginseng marc with aluminum sulfate was effective in decreasing methane and propionic acid released from poultry litter.

• 한국염색가공학회지
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• 제10권6호
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• pp.55-66
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• 1998

In order to investigate the detergency effects of various detergents to stained polyester & cotton fabric with solid soils such as carbon black, liquid paraffin and fat, the optimum washing conditions according to the types of washing agent, the assesment of detergency effect by the measurement of reflectance after and before washing were studied. The detergency effect of various detergents to stained polyester and cotton fabric increased by using the mixtures of bleaching and enzyme detergent. In order to obtain the excellent detergency effect, 2-step treatment, the pre-washing with bleaching agent and bleaching-enzyme mixture detergent treatment is preferred. In comparison of the detergency to polyester and cotton fabric, it is assumed that the detergency to polyester stained fabric was superior than that to cotton stained fabric because of the difference of adhesive force between soil material and fabric in preparing solid stained fabric.