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        검색결과 18

        1.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Occupational safety and health management expenses in the construction industry are statutory and separately included in the cost statement to prevent occupational accidents and health problems. The expenses are determined by multiplying the standard amount by the rate decided according to construction types and scales. However, the current expense appropriation method does not properly reflect the recent changes in the construction industry such as industry size, industry diversification, and social atmosphere about safety reinforcement. This study surveyed 1579 questionnaires in total and analyzed expense execution rate and proportion of each expense category. The expense execution rate was relative higher in complex construction (e.g., heavy construction = 126%, civil engineering = 125%) and long-period project (equal to or over 48 months construction = 133%) compared to general construction (98~116%) and short-period project (less than 48 months construction = 115%). The proportion of spending expenses was higher in the category of safety manager labor costs (25~52%), safety facility costs (22~40%), and personal protective equipment costs (10~25%). The analysis results of the study can be utilized in revising the standard expense appropriation method by reflecting the current usages of the occupational safety and health management expenses in the construction industry.
        4,000원
        3.
        2022.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Percutaneous balloon dilation with or without placement of an external biliary drain is a nonoperative alternative method for treating benign bilioenteric anastomotic strictures. Although this procedure has a high technical success rate, outcomes are less optimal when attempting to dilate refractory tight strictures. For the stricture, cutting balloon can be an option. We present four patients with benign bilioenteric anastomotic strictures refractory to conventional balloon dilation. To the patients, a peripheral cutting balloon over-the-wire system was inflated, following subsequent conventional non-compliant balloon dilation. After the balloon dilation treatment, an external drainage catheter was placed through the stricture site and maintained for up to 30 days. Technical and end-treatment success was achieved in all four patients. In conclusion, the use of cutting balloon dilation may appear to be a safe and effective alternative method of treatment in patients with benign bilioenteric anastomotic strictures refractory to conventional balloon dilation.
        4,000원
        5.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Researcher of this study improved conventional circle secondary settling basin, through the way such as extend of inlet pipe length, introduction of device for inducting uniforming of flow, keeping of height of sludge interface. Also, we compared conventional circle settling basin to improved circle settling basin the water treatment efficiency. Result of research, when SVI is average 117, improvement rate of SS and BOD were 51.0%, 37.0% approximately compared to conventional settling basin. And when SVI is average 178, improvement rate of SS and BOD were 22.7%, 36.0% approximately. Also when SVI is average 196, improvement rate of SS and BOD were 24.7%, 30.3% approximately. When it’s winter, improvement rate of SS, BOD, COD, TN and TP were 20.6%, 17.9%, 13.9%, 13.5%, 12.4% approximately. Therefore, we can be the judge, this improved settling basin can be used as the final settling basin in the waste water treatment plant.
        4,000원
        11.
        2011.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        쌀부산물인 탈지미강을 상업적으로 사용되는 8가지 protease를 최적화된 조건에서 단일 혹은 혼합 처리하여 수용성 단백질을 분리하였다. 이렇게 분리된 단백질을 Lowry, Kjeldahl 그리고 Gravimetric method 등 총 3가지 방법으로 분석을 한 결과 Protamex, Alcalase, Protease N이 가장 높은 분해율을 나타냈다. 3가지 방법에서 모두 Protamex, Alcalase, Protease N이 가장 높은 분해율을 나타내었고, Gravimetric method의 경우 다른 두 분석방법인 Lowry, Kjeldahl method에 비해 더 높은 단백질 함량을 보였다. 또한 위의 단일처리결과를 바탕으로 3가지 protease를 혼합하여 처리하였을 때 단일효소처리에 비해 상승효과가 나타나는 것을 알 수 있었는데, 이것은 protease의 경우 가수분해 할 수 있는 특정 peptide 혹은 amino acid가 있는데 각각의 protease가 분해하지 못하는 peptide 혹은 amino acid를 서로 분해해줌으로써 상승효과가 나타난 것으로 생각된다. 효소처리를 하여 얻어진 단백질의 사이즈를 알아보기 위해 SDS PAGE를 한 결과 어떠한 밴드도 형성이 되지 않았고 이는 분해된 단백질이 marker의 최소 사이즈인 15 kDa보다 작기때문인 것으로 생각된다. 따라서 일반 단백질보다 사이즈가 작은 polypeptide나 amino acid로써 분해된 것을 뜻하고 실제로 섭취하였을 때는 신체에서 생성되는 단백질 분해효소인 trypsin이나 chymotrypsin의 분해 없이도 쉽게 흡수 할 수 있을 것이라 판단된다. 또한 효소의 종류가 많을수록 총 아미노산의 함량이 높아짐으로써 식품첨가물로써 활용도가 높은 단백질가수분해물로 분해되었음을 확인할 수 있었다.
        4,000원
        12.
        1994.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was carried out to clarify the pedigree identification from blood typing of 301 Hoisteins in National Animal Breeding Institute(N.A.B.I.). Twenty kinds of standard reagent standardized by Insternational Society for Animal Blood Group Research provied from KNC improvement center, N, L, C, F. were used as the reference reagents in this study. The highest frequency of antigenic facfors was obtained from Xin blood typing of 301 Holsteins. The frequency of X was 0.714.In A blood system, four kinds of phenogroups were observed. The gene frequencies of Al and Z' phenogroups were equally 0.027.This frequency was greatly lower than those of breeds of Southern European and Zebu cattle. In B blood Systern, nineteen kinds of blood type were appeared. The appearance frequency of Gx blood type was 0.259, whish was higher than the others. In C blood system, thirty kinds of blood type were observed. The appearance frequency of X blood type was the highest(0.189). In F blood system, three kinds of alleles were detected. The gene frequency of F allele was higher than that of V(0.105). However, the frequency of F allele(0.327) was greatly lower than that of "- /- " allele. In S blood system, twelve kinds of blood type were appeared and showed sirnilar appearance frequencies except " - / - " allele. From the results of the pedigree identification from 8 sires and 28 progenies of them, the accuracy of pedigree identification was 92.9%.ification was 92.9%.
        4,000원
        13.
        2004.10 KCI 등재 서비스 종료(열람 제한)
        The purpose of this research was evaluated economical effect to apply alternative external carbon source. Conventional activated sludge process in municipal wastewater treatment plant was adapted and introduced to Biological nutrient removal processes to meet the newly enforced effluent quality standard for nutrient removal in Korea. Low COD/NH4+-N ratio and higher nutrient concentration of influent characteristics force to inject external carbon source for denitrifying recycled nitrate. In the most case, methanol was used as external carbon source. But Methanol is expensive and very dangerous in handling. So we could find cheaper and safer external carbon source substituted methanol in last study. This alternative external carbon source is named RCS(recoverd carbon source) and a by-product of fine chemical product at chemical plant. When RCS was applied real municipal wastewater treatment plant, average 55~65% of T-N removal efficiency, 8.8mg/l of effluent T-N concentration, 11.3mg/l of effleunt COD concentration were obtained without effluent COD increase as against used methanol. To apply RCS in municipal wastewater treatment plant obtain approximately 74.5% expenditure cost reduction in comparison with methanol dosage cost.
        14.
        2004.03 KCI 등재 서비스 종료(열람 제한)
        The SBR(Sequencing Batch Reactor) process is ideally suited to treat high loading wastewater due to its high dilution rate. SBR operates by a cycle of periods consisting of filling, reacting, settling, decanting and idling. The react phases such as aeration or non-aeration, organic oxidation, nitrification, denitrification and other biological reactions can be achieved in a reactor. Although the whole reactions can be achieved in a SBR with time distributing, it is hard to manage the SBR as a normal condition without recognizing a present state. The present state can be observed with nutrient sensors such as NH4+-N, NO2--N, NO3--N and PO43--P. However, there is still a disadvantage to use the nutrient sensors because of their high expense and inconvenience to manage. Therefore, it is very useful to use common on-line sensors such as DO, ORP and pH, which are less expensive and more convient. Moreover, the present states and unexpected changes of SBR might be predicted by using of them. This study was conducted to get basic materials for making an inference of SBR process from ORP(oxidation reduction potential) of synthetic wastewater. The profiles of ORP, DO, and pH were under normal nitrification and denitrification were obtained to compare abnormal condition. And also, nitrite and nitrate accumulation were investigated during reaction of SBR. The bending point on ORP profile was not entirely in the low COD/NOx ratio condition. In this case, NOx was not entirely removed, and minimum ORP value was presented over -300mV. Under suitable COD/NOx ratio which complete denitrification was achieved, ORP bending point was observed and minimum ORP value was under -300mV. Under high COD/NOx ratio, ORP bending point was not detected at the first subcycle because of the fast denitrification and minimum ORP value was under -300mV at the time.
        16.
        1997.12 KCI 등재 서비스 종료(열람 제한)
        Sequencing Batch Reactor(SBR) experiments for organics and nutrients removal have been conducted to find an optimum anaerobic/anoxic/aerobic cycling time and evaluate the applicability of oxidation-reduction potential(ORP) as a process control parameter. In this study, a 6 ℓ bench-scale plant was used and fed with night-soil wastewater in K city which contained TCODcr : 10,680 ㎎/ℓ, TKN : 6,893 ㎎/ℓ, NH_4^+ -N : 1,609 ㎎/ℓ, PO_4^3- -P : 602 ㎎/ℓ on average. The cycling time in SBRs was adjusted at 12 hours and 24 hours, and then certainly included anaerobic, aerobic and anoxic conditions. Also, for each cycling time, we performed 3 series of experiment simultaneously which was set up 10 days, 20 days and 30 days as SRT. From the experimental results, the optimum cycling time for biological nutrient removal with night-soil wastewater was respctively 3hrs, 5hrs, 3hrs(anaerobic-aerobic-anoxic). Nitrogen removal efficiency was 77.9%, 77.9%, 81.7% for each SRT, respectively. When external carbon source was fed in the anoxic phase, ORP-bending point indicating nitrate break point appeared clearly and nitrogen removal efficiency increased as 96.5%, 97.1%, 98.9%. Phosphate removal efficiency was 59.8%, 64.5%, 68.6% for each SRT. Also, we finded the applicability of ORP as a process control parameter in SBRs.
        17.
        1997.10 KCI 등재 서비스 종료(열람 제한)
        In the study, we investigated the behavior and removal efficiency of organics, nitrogen, phosphorus with operating conditions in SBRs. Substrate used was synthetic wastewater in which the ratio of COD_cr : N : P was 100 : 12 : 2. The cycling time in SBRs was adjusted at 6 hours and 8 hours, and then certainly included anaerobic and aerobic conditions. Also, for each cycling time, we performed 2 series of experiment simultaneously which was set up 10 days and 20 days as SRT. The removal efficiency of COD_cr, was over 97% in all operating conditions. In the 6 hours cycling time, the removal efficiency of PO_4^3- -P reached almost 100% in steady state. And then we could observe a typical phenomena of phosphorus release and uptake, and the removal efficiency of N was 67%. Residual N source was almost TKN and most of the rest remained as NO_2^- -N. Also the difference in both SRTs was not observed practically. In the 8 hours cycling time, dissolution of sludge appeared. and, PO_4^3- -P was not nearly removed but nitrogen was removed up to 75%. And the residual nitrogen was accumulated as NO_2^- -N.