• Fisheries and Aquatic Sciences
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• 제9권4호
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• pp.160-166
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• 2006

We explored the possibilities of using the freshwater rotifer Brachionus angularis as a live food for small fishes cultured in fresh- or brackish waters. Brachionus angularis were collected from a reservoir for isolation and laboratory culture. Length and width of the lorica were $102.3{\mu}m$ and $76.6{\mu}m$, respectively, and those of amictic eggs were $64.4{\mu}m\;and\;47.9{\mu}m$, respectively. When their growth rates were examined at six different temperatures, i.e., 15, 20, 25, 30, 35, and $40^{\circ}C$, the highest daily growth rate of 0.801 was observed at $35^{\circ}C$, and growth was lower with decreasing temperature. Adaptation to salinity change was evaluated with two different modes of salinity increase: step-wise elevation lasting for short durations of 5 to 30 min or a long duration of 24 h. With the short duration modes, no individuals survived salinity higher than 10 psu, and the number of live individuals did not increase throughout the experiment. However, in the 24-h elevation, the number of individuals increased when salinity was elevated by 1 to 2 psu per day for the first 2 or 3 days, while no increase in number occurred at salinity increments higher than 3 psu per day. In addition, to assess the effect of different diets, four single-component diets (Chlorella vulgaris, Nannochloris sp., baker's yeast, or dry yeast) and three combination diets (C. vulgaris + Nannochloris sp. + baker's yeast + dry yeast; C. vulgaris 70% + baker's yeast 30%; C. vulgaris 30% + baker's yeast 70%) were used. The specific growth rates of B. angularis fed combination diets were higher than those of rotifers fed any single-component diet, with the highest rate of 0.648 in B. angularis fed a mixture of C. vulgaris, Nannochloris sp., baker's yeast, and dry yeast, and the lowest rate of 0.200 in those fed dry yeast only. Our results indicate that the freshwater rotifer B. angularis can be used for seedling production of both freshwater and brackish-water fishes that require small (less than about $120{\mu}m$) live food during their early stages.

• KSBB Journal
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• 제18권6호
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• pp.529-535
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• 2003

본 연구에서는 등$.$경유 혼합물을 Pseudomonas aeruginosa F722를 이용하여 분해시킬 때 생분해율에 미치는 생물계면활성제, 화학계면활성제 및 공기 공급량의 영향을 조사하였다. 그 결과, 탄화수소 분해율은 0.01%와 0.15% 농도의 생물계면활제를 첨가하였을 때가 0.05%, 0.1% 및 0.2%농도의 생물계면활제를 첨가하였을 때보다 최고 6.2% 높은 94.3, 94.2% 제거율을 나타냈다. 하지만, 0.15% 생물계면활제를 첨가하였을 때가 0.01% 생물계면활제를 첨가하였을 때보다 탄화수소 분해율이 더 안정적이었다. 그리고 생물계면활성제 (surface tension; 30mN/m)와 화학계면활성제 (Tween 80;39mN/m, detergent;31mN/m)를 0.15% 농도로 첨가하여 배양하였을때, 탄화수소 분해율은 94.2, 93.5, 93.4%로 비슷하였다. 하지만, P. aeruginosa F722의 개체수는 생물계면활성제를 첨가했을 때가 화학계면활성제를 첨가했을 때보다 2배 이상 증가된 19 ${\times}$ $10^{7}$ cfu/$m\ell$로 조사되었다. 0.5vvm으로 공기를 공급하면서 교반을 수행하였을 때, 배양 3일 후, 사용균주를 접종하지 않은 공시험에서 탄화수소 분해율은 68.8%였으며, P. aeruginosa F722를 접종하였을 때는 94.8%이었다. 0.5 vvm으로 공기를 공급하였을 때가 공기를 공급하지 않았을 때보다 배양시간이 1/3로 단축되었다. 그리고 교반배양 (3일)과 정치배양 (10일)에서 탄화수소 분해율은 각각 94.8, 93.7%였다.

• 한국건축시공학회지
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• 제20권4호
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• pp.331-338
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• 2020

본 연구는 CGS를 콘크리트용 혼합골재로서 활용성을 검토하기 위하여 양호한 입도분포의 부순잔골재(CSa) 및 미립자인 해사와 굵은 입자의 부순잔골재를 혼합한 혼합골재(MS)에 CGS의 치환율 변화에 따른 콘크리트의 기초적 특성 및 내구성을 분석하였다. 실험결과, 슬럼프 및 슬럼프 플로는 CSa 및 MS 모두 CGS 치환율이 증가할수록 증가하였으며, 공기량은 반대로 감소하였다. 압축강도는 CSa를 사용한 경우 CGS 치환율이 증가할수록 저하하였지만, MS를 사용한 경우는 CGS 50 %에서 최대치를 나타내었다. 콘크리트 내구성을 검토한 결과로, 건조수축 및 탄산화 깊이측정의 경우는 CGS 치환율에 따라 양호한 성능을 나타내었다. 하지만, 내동해성에서는 전반적으로 CGS 치환율이 증가할수록 감소하는 것으로 나타났다. 따라서, CGS를 치환 사용하는 혼합잔골재 콘크리트의 경우는 공기량 감소를 보완할 수 있도록 AE제 추가 투입 등의 대책을 수립한다면, 큰 문제 없을 것으로 판단된다.

• 대한치과보철학회지
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• 제44권3호
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• pp.284-294
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• 2006

Statement of problem. Proliferation of Candida albicans is primarily within the plaque on the fitting surface of the denture rather than on the inflamed mucosa. Consequently, the treatment of the denture is equally important as treatment of the tissue. Cleansing and disinfection should be efficiently carried-out as the organisms can penetrate into the voids of the acrylic resin and grow in them, from which they can continue to infect and reinfect bearing tissues. Purpose. The purpose of this study was to evaluate the applicability of photocatalytic reaction to eliminate Candida albicans from acrylic resin denture base, and to investigate the anti-fungal effect with various UVA illumination time. Materials and Methods. The specimens were cured by the conventional method following the manufacturer's instruction using thermal polymerized denture base resin (Vertex RS: Dentimex, Netherlands). $TiO_2$ photocatalyst sol(LT), which is able to be coated at normal temperature, was made from the Ti-alkoxide progenitor. The XRD patterns, TEM images and nitrogen absorption ability of the $TiO_2$ photocatalyst sol(LT) were compared with the commercial $TiO_2$ photocatalyst P-25. The experimental specimens were coated with the mixture of the $TiO_2$ photocatalyst sol(LT) and binder material (silane) using dip-coater, and uncoated resin plates were used as the control group. Crystallinity of $TiO_2$ of the specimen was tested by the XRD. Size, shape and chemical compositions were also analyzed using the FE-SEM/ EDS. The angle and methylene blue degradation efsciency were measured for evaluating the photocatalytic activity of the $TiO_2$ film. Finally, the antifungal activity of the specimen was tested. Candida albicans KCTC 7629(1 ml, initial concentration $10^5$ cells/ ml) were applied to the experiment and control group specimens and subsequently two UVA light source with 10W, 353 nm peak emission were illuminated to the specimens from 15cm above. The extracted $2{\mu}l$ of sample was plated on nutrient agar plate ($Bacto^{TM}$ Brain Heart Infusion; BD, USA) with 10 minute intervals for 120 minute, respectively. It was incubated for 24 hours at $37^{\circ}C$ and the colony forming units (CFUs) were then counted. Results. Compared the characteristics of LT photocatalyst with commercial P-25 photocatalyst, LT were shown higher activity than P-25. The LT coated experimental specimen surface had anatase crystal form, less than 20 nm of particle size and wide specific surface area. To evaluate the photocatalytic activity of specimens, methylene blue degradation reaction were used and about 5% of degradation rate were measured after 2 hours. The average contact angle was less than $20^{\circ}$ indicating that the LT photocatalyst had hydrophilicity. In the antifungal activity test for Candida albicans, 0% survival rate were measured within 30 minute after irradiation of UVA light. Conclusion. From the results reported above, it is concluded that the UVA-LT photocatalytic reaction have an antifungal effect on the denture surface Candida albicans, and so that could be applicable to the clinical use as a cleaning method.

• Asian-Australasian Journal of Animal Sciences
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• 제31권8호
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• pp.1221-1229
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• 2018

Objective: A study was conducted to evaluate the varietal differences among faba bean straws and also to assess the potentials of faba bean straws supplemented with concentrate fed at the rate 70% straws and 30% concentrate mixture on feed intake, digestibility, body weight gain and carcass characteristics of the animals. Methods: Forty yearling Arsi-Bale sheep with initial body weight of $19.85{\pm}0.29kg$ (mean${\pm}$standard deviation) were grouped in a randomized complete block design into eight blocks of five animals each based on their initial body weight. Straws included in the study were from Mosisa (T1M), Walki (T2W), Degaga (T3D), Shallo (T4S), and local (T5L) varieties of faba bean and concentrate (2:1 ratio of wheat bran to "noug" seed cake). The experiment consisted of seven days of digestibility and 90 days of feeding trials followed by evaluation of carcass parameters at the end. Results: Local variety had lower (p<0.05) in grain and straw yield compared to improved varieties but higher in crude protein, metabolizable energy contents and in vitro organic matter digestibility. The apparent digestibility of dry matter and crude protein of sheep fed Walki and Mosisa straws were higher than (p<0.05) straws from Shallo varieties. Sheep fed Walki straw had greater (p<0.05) dry matter intake, average daily gain and feed conversion efficiency than sheep fed local and Shallo straws. Slaughter body weight and empty body weight were higher (p<0.05) for sheep fed Mosisa and Walki straws as compared to sheep fed Shallo straws. Apart from this, the other carcass components were not affected (p>0.05) by variety of the faba bean straws. Conclusion: There is significant varietal differences between faba bean straws both in quality and quantity. Similarly, significant variation was observed in feed intake, digestibility, body weight gain and feed conversion efficiency among sheep fed different straws of faba bean varieties with concentrate supplement. Based on these results, Walki and Mosisa varieties could be recommended as pulse crop rotation with cereals in the study area.

• 보존과학연구
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• 통권33호
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• pp.5-17
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• 2012

Ola 잎에 글씨를 새긴 다음 그 홈을 Vateria acuminata Hyne의 뿌리로 만든 식물성 오일과 탄소 가루를 섞어 채운 올라 잎 기록물은 스리랑카에서 사용되는 기록 방법 중의 하나이다. 문헌상에 따르면 올라 잎 기록물은 1세기부터 18세기까지 사용되었다. Ola 잎 기록물이 400여 년 동안 보관되어 왔다는 최근의 발견과 좋은 보존 상태로 보아 이 식물성 오일이 올라 잎을 곰팡이와 곤충 같은 생물학적 요인과 환경 요인으로부터 보호해 주는 것으로 보인다. 이 식물성 오일의 항균 활성을 측정하기 위하여 해인사 장경판전에서 분리한 곰팡이와 올라 잎에서 분리한 균을 배양한 후 억제 효과를 확인하였다. 균 현탁액을 평판배지에 도말한 다음 식물성 오일을 흡수시킨 페이퍼 디스크를 평판배지에 올린다. 이 실험에서 식물성 오일은 육안 상 분명한 투명환을 형성하였으며 곰팡이나 세균과 같은 미생물의 성장을 저해하는 것을 확인하였다. 이 결과로 보아 Vateria acuminata Hyne의 식물성 오일은 항세균 및 항진균 활성을 가지고 있다는 것을 나타낸다.

• Restorative Dentistry and Endodontics
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• 제22권2호
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• pp.670-679
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• 1997

The pH changes in 4 small cavities prepared at the facial inner dentin and lingual outer dentin of the cervical and apical portion of root filled with calcium hydroxide pastes were investigated. Forty extracted permanent teeth with single canal were instrumented with step-back method, and then 4 small cavities were prepared. Two inner dentin cavities were cut a distance of about 1.0mm from the canal wall and two outer dentin cavities were cut to a depth of about 0.5mm from the root surface. Root canals and prepared cavities were flushed with 17% EDTA, and then irrigated with 5% NaOCl to remove smear layer. Teeth were randomly divided into four groups. Control group was not filled and the remaining other groups were filled with mixture of calcium hydroxide and distilled water, Vitapex$^{(R)}$ paste and Pulpdent$^{(R)}$ paste respectively. The pH change of the dentin in each cavity was measured at 0, 1, 3, 7, 14, 21, 28, 60, 90 days with pH microelectrode(WPI Co., USA). The results were as follows : 1. The groups obturated with Pulpdent$^{(R)}$ paste and Aqueous calcium hydroxide produced the increased pH level at 1 day and maintained plateau over next 3weeks and decreased after 3weeks. 2. The group obturated with Vitapex$^{(R)}$ paste observed no significant pH change until 2weeks and slight increased pH at 3weeks and sequential increasing after 3weeks. But, the pH in the group obturated with Vitapex$^{(R)}$ paste remained significantly below the pH measured in the other two experimental groups(P<0.05). 3. All experimental groups showed pH level similar to control group after 28 days. 4. The pH of outer dentin is slightly higher than that of inner dentin. There is no significant difference in pH level between apical and cervical dentin throughout the duration of the experiment, though apical dentin showed slightly higher pH than cervical dentin at 1 day(P<0.05).

• 한국수학교육학회지시리즈A:수학교육
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• 제42권2호
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• pp.203-218
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• 2003

The purpose of this study is to see what the essential characteristics are in teaching probability and statistics among various mathematical fields. we also tried to connect the study of probability and statistics education with what is needed for a science be synthetic to have its own identity as a unique research field. Since we searched for the future direction of the pedagogic study in the probability and statistics we first selected papers on probability and statistics published in (Series A), the Journal of Korea Society of Mathematical Education, and establish the following research questions. What kinds of characteristics can be found when papers on probability and statistics published in (Series A) are classified into low categories; contents of probability and statistics education, research method of the mathematics education, methods of teaming and teaching, and finally measurements and evaluation\ulcorner We classified papers into two kinds. One is related to the educational contents, consisting of the methods of learning and teaching, and of the measurement and evaluation. The other is reined to the methods of research, which is not a part of the educational curriculum but is essential for establishing the identity of mathematics education. According to the periods, papers on the curricular contents in 1960s were influenced by the New Mathematics, and papers on the curricular contents in 1980s were influenced by 'back to basic'. In 1990s, papers on methods of learning and teaching, and measurement md evaluation were increasing in number. Besides, (series A) from the Journal of Korea Society of Mathematical Education covers contents, methods of Loaming and teaching, and measurement and evaluation. And when I examined the papers on the contents of textbook of a junior high school related to the probability and statistics education and on methods of learning and teaching, 1 found that those papers occupy 1.84% in . When it comes to the methods of loaming and teaching, most of studies in (series A) are about application of concrete implement like experiment and practical application of computer programs, Through this study, I found that over-all and more active researches on probability and statistics are required and that the studies about methods of loaming and teaching must be made in diverse directions. It is needed that how students recognize probability and statistics, connection, communication and representation in probability and statistics context, too. (series A) does not have papers on methods of study. Mathematics pedagogy is a mixture of various studies - mathematical psychology, mathematical philosophy, the history of mathematics and Mathematics. So If there doesn't exist a proper method of study adequate in the situation for the mathematics education the issue of mathematics pedagogy might be taken its own place by that of other studies'. We must search for the unique method of study fur mathematics education so that mathematics pedagogy has its own identity as a study. The study concerning this aspect is needed.

• 한국식품영양학회지
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• 제10권4호
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• pp.544-548
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• 1997

인산염의 첨가가 조기 및 갈치연육의 보수력 및 단백질의 용출성에 미치는 영향과 가열처리 후에 조기육을 원료로 가공한 어묵의 texture에 미치는 영향을 조사하기 위하여 인산염을 첨가하지 않은 대조구와 4종의 시판 복합 인산염을 첨가수준별로 사용했을 때의 기능적 성질을 분석 검토하였다. 연육의 보수력 및 염용성 단백질량은 조기연육에는 인산염 B(sodium pol-phosphate 50%, sodium pyro-phosphate 20%, sodium tetra meta-phosphate 20%, sodium acid pyro-phosphate 5%, sodium ultra meta-phosphate 5%)를, 갈치연육에는 인산염 C(sodium poly-phosphate 40%, sodium pyro-phosphate 30%, potassium pyro-phosphate 15%, sodium tetra meta-phosphate 10%, hexa meta-phosphate 5%)를 각각 0.4% 첨가한 경우가 가장 효과적이었고 그 때의 염용성 단백질의 용출량은 조기연육이 954mg%, 갈치연육이 686mg%였다. 조기육을 원료로 하여 가공한 어묵의 적정 가열조건은 85$^{\circ}C$에서 45분간 가열한 것이 조직감이 양호하였다. 한편 121$^{\circ}C$에서 10분간 가열한 경우는 C 인산염이 다른 인산염에 비하여 어육 단백질의 열안 정성이 높은 것으로 나타났다.

• 대한약리학회지
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• 제14권1_2호
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• pp.47-54
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• 1978

Recently, a major resection of the pancreas has been carried out not only to treat carcinoma of pancreas but also chronic pancreatitis. But limited and often contradictory reports have been made on the exocrine effects after partial surgical pancreatectomy in mammals. It was suggested that the growth of the residual tissue in pancreatectomized rat is very active, because pancreas has the great power of regeneration after partial pancreatectomy, while others observed that rat pancreas after partial surgical resection revealed a perplexing mixture of atrophy and regeneration of acinar tissue. On the other hand, another results showed that the amount of insulin required to control diabetes after partial resection of pancreas is much greater than that needed after total pancreatectomy. Because the anti-insulin system, such as glucagon secretion and hypophyseoadrenal function, is probably depressed after total pancreatectomy. Furthermore, minimal resection line which will not influence the normal function of pancreas is not agreeable, such 75%, 80% or 95% resection of the total pancreas in rat. So far, studies on the exocrine function other than endocrine function after partial pancreatectomy have been limited. Therefore, the main purpose of this study is to examine the changes of exocrine as well as endocrine function of pancreas at the different time interval after 60% or 80% pancreatectomy in rats. The results summerized as follow: 1) In both 60% and 80% resected groups, a slight decrease of the total body weight was observed at a day after partial pancreatectomy in rats, but the body weight was continued to increase for following 100 days. 2) The weight of residual pancreas was continuously increased during experiment in both 60% and 80% resected groups. But the content of tissue protein in residual pancreas was significantly decreased comparing with those of resected pancreas. 3) The flow rate of pancreatico-biliary juice was significantly decreased immediately after pancreatectomy in both resected groups. But it was recovered to control level after a day in 60% resected group, after 30 days in 80% resected group. 4) The output of amylase and lipase in resected groups were significantly decreased right after pancreatectomy comparing with control group. In the 60% resected group, the output of amylase was recovered during the following 100 days after pancreatectomy, while lipase output in 3 days. However, in the 80% resected group, the output of amylase and lipase were not recovered during 100 days after pancreatectomy. 5) In order to examine the endocrine function, blood sugar level were examined at all experimental periods after partial pancreatectomy. There was no difference between control and 60% resected group in the sugar level. But in the 80% resected group the level was significantly incresed immediately after pancreatectomy, and reached the highest level at 3 days. Then it was decreased to control level during the next 10 days after pancreatectomy. The above results showed that in 60% resected group little changes were observed on pancreatic function, but severe functional impairments were observed in 80% resected group. This results suggested that the endocrine function was recovered within a short period, although the exocrine function was not recovered for a long time after 80% pancreatectomy in rats.