• 셀메드
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• 제2권4호
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• pp.37.1-37.4
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• 2012

In the present study, the volatile oil, chloroform extract and methanol extract of the woods of the plants Cedrus deodara and Pinus roxburghii were screened for their antibacterial and antifungal activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Streptococcus pyogenes, Candida albicans, Aspergillus niger, and Aspergillus clavatus using the Agar diffusion method. The susceptibilities of the microorganisms to the extracts were compared with each other and with a selected standard antibiotic. It was observed that the volatile oil and chloroform extracts showed the significant antibacterial activities while the least antibacterial activity was recorded with the methanolic extracts. The higher Minimum Inhibitory Concentration value of the extracts and oils against fungus suggested that the plants may possess less antifungal activity. Phytochemical analysis and thin-layer chromatography profiling revealed the presence of flavonoids and terpenoids in the oil and chloroform extracts, which could explain the antimicrobial activity. The findings suggest that the Cedrus deodara and Pinus roxburghii have antimicrobial properties and they can be used in the treatment of infectious diseases. However, further work is required in order to isolate the active constituents of the plants responsible for the antibacterial activity.

• Journal of Electrical Engineering and Technology
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• 제4권3호
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• pp.323-329
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• 2009

This paper presents a new approach for thermal unit commitment (UC) using a differential evolution (DE) algorithm. DE is an effective, robust, and simple global optimization algorithm which only has a few control parameters and has been successfully applied to a wide range of optimization problems. However, the standard DE cannot be applied to binary optimization problems such as UC problems since it is restricted to continuous-valued spaces. This paper proposes binary differential evolution (BDE), which enables the DE to operate in binary spaces and applies the proposed BDE to UC problems. Furthermore, this paper includes heuristic-based constraint treatment techniques to deal with the minimum up/down time and spinning reserve constraints in UC problems. Since excessive spinning reserves can incur high operation costs, the unit de-commitment strategy is also introduced to improve the solution quality. To demonstrate the performance of the proposed BDE, it is applied to largescale power systems of up to 100-units with a 24-hour demand horizon.

• Nuclear Engineering and Technology
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• 제36권6호
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• pp.559-570
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• 2004

A computational fluid dynamics model for predicting moderator circulation inside the Canada deuterium uranium (CANDU) reactor vessel has been developed to estimate the local subcooling of the moderator in the vicinity of the calandria tubes. The buoyancy effect induced by the internal heating is accounted for by the Boussinesq approximation. The standard $k-{\varepsilon}$ turbulence model with logarithmic wall treatment is applied to predict the turbulent jet flows from the inlet nozzles. The matrix of the calandria tubes in the core region is simplified to a porous media in which the anisotropic hydraulic impedance is modeled using an empirical correlation of pressure loss. The governing equations are solved by DFX-4.4, a commercial CFD code developed by AEA technology. The resultant flow patterns of the constant-z slices containing the inlet nozzles and the outlet port are "mined-type", as observed in the former 2-dimensional experimental investigations. With 103% full power for conservatism, the maximum temperature of the moderator is $82.9^{\circ}C$ at the top of the core region. Considering the hydrostatic pressure change, the minimum subcooling is $24.8^{\circ}C$.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2002년도 춘계 학술대회지
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• pp.53-57
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• 2002

Quality evaluation must be more developed in order to offer the sufficient information for producer, distribution centers buyer, consumer. There are many parameters which influence the rice quality and cooked rice. It is difficult to evaluate the quality of rice and cooked rice by only some parameters. In the case of rice quality evaluation in Korea, physicochemical inspection is performed by examining the minimum and maximum limits of brown rice recovery, moisture content, damaged kernel, and colored kernel as inspection standard. Marketing standard of rice defines the limits of perfect, white core and belly, colored, damaged kernels, and broken rice, classifying into special, excellent, and normal grades. As a research direction for the development of rice quality evaluation, establishment as parts of technical field, must be further developed as follows : more detailed measure of characters, search of unknown taste-related components, creation and grade classification of quality evaluation factors at each management stages of treatment after harvesting, evaluation as food material as well as cooking rice, method development for simple evaluation and establishment of equation for palatability. In the side of policy, the following concerns must be conducted: price discrimination in conformity to rice cultivar and grade under the basis of qualify evaluation method developed, fixation of head rice branding, and introduction of low temperature circulation.

• Journal of Veterinary Science
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• 제23권1호
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• pp.1.1-1.11
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• 2022

Background: The poor bioadhesion capacity of tilmicosin resulting in treatment failure for Staphylococcus aureus small colony variants (SASCVs) mastitis. Objectives: This study aimed to increase the bioadhesion capacity of tilmicosin for the SASCVs strain and improve the antibacterial effect of tilmicosin against cow mastitis caused by the SASCVs strain. Methods: Tilmicosin-loaded chitosan oligosaccharide (COS)-sodium carboxymethyl cellulose (CMC) composite nanogels were formulated by an electrostatic interaction between COS (positive charge) and CMC (negative charge) using sodium tripolyphosphate (TPP) (ionic crosslinkers). The formation mechanism, structural characteristics, bioadhesion, and antibacterial activity of tilmicosin composite nanogels were studied systematically. Results: The optimized formulation was comprised of 50 mg/mL (COS), 32 mg/mL (CMC), and 0.25 mg/mL (TPP). The size, encapsulation efficiency, loading capacity, polydispersity index, and zeta potential of the optimized tilmicosin composite nanogels were 357.4 ± 2.6 nm, 65.4 ± 0.4%, 21.9 ± 0.4%, 0.11 ± 0.01, and -37.1 ± 0.4 mV, respectively; the sedimentation rate was one. Scanning electron microscopy showed that tilmicosin might be incorporated in nano-sized crosslinked polymeric networks. Moreover, adhesive studies suggested that tilmicosin composite nanogels could enhance the bioadhesion capacity of tilmicosin for the SASCVs strain. The inhibition zone of native tilmicosin, tilmicosin standard, and tilmicosin composite nanogels were 2.13 ± 0.07, 3.35 ± 0.11, and 1.46 ± 0.04 cm, respectively. The minimum inhibitory concentration of native tilmicosin, tilmicosin standard, and tilmicosin composite nanogels against the SASCVs strain were 2, 1, and 1 ㎍/mL, respectively. The in vitro time-killing curves showed that the tilmicosin composite nanogels increased the antibacterial activity against the SASCVs strain. Conclusions: This study provides a potential strategy for developing tilmicosin composite nanogels to treat cow mastitis caused by the SASCVs strain.

• 환경영향평가
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• 제27권4호
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• pp.394-401
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• 2018

본 연구는 환경영향평가의 생태면적률의 인구, 지역, 사업 유형, 총 사업면적에 따른 경향성을 분석하였다. 생태면적률은 총대지면적 중 생태적 기능이 있는 토지면적의 비율로, 생태계 보존과 개발된 단지에서 생활하는 시민들의 건강과 삶의 질에 중요한 요소이다. 현재 환경영향평가에서는 가중치가 고려된 생태면적과 총 사업면적의 비로 생태면적률을 산출하며, 각 사업 유형 별로 최소 목표 생태면적률을 제시하여 최소한의 생태면적을 확보하도록 하고 있다. 경향성에 대한 평가는 도시의 개발, 산업입지 및 산업단지 조성, 관광단지 개발, 폐기물처리시설 및 분뇨처리시설의 설치 사업 등 총 4가지 사업에 대하여 총 55개의 표본을 근거로 하였다. 본 연구는 경향성을 분석한 결과 인구에 대한 고려가 반영된 척도, 사업빈도와 지역 전체를 고려한 생태면적률 조정, 그리고 최소달성치 달성 여부에 대한 규제 강화를 통해 현 제도를 개선해야 한다는 결론을 얻었다. 본 연구 이후로 더 많은 수의 데이터를 포함한 광범위한 연구와, 구체적 제도개선에 대한 연구가 후속되어야 한다.

• 상하수도학회지
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• 제27권3호
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• pp.313-324
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• 2013

It is widely known that untreated Combined Sewer Overflows (CSOs) that directly discharged from receiving water have a negative impact. Recent concerns on the CSO problem have produced several large scale constructions of treatment facilities, but the facilities are normally designed under empirical design criteria. In this study, several criteria for defining CSOs (e.g. determination of effective rainfall, sampling time, minimum duration of data used for rainfall-runoff simulation and so on) were investigated. Then this study suggested a standard methodology for the CSO calculation and support formalized standard on the design criteria for CSO facilities. Criteria decided for an effective rainfall was over 0.5 mm of total rainfall depth and at least 4 hours should be exist between two different events. An Antecedent dry weather period prior to storm event to satisfy the effective rainfall criteria was over 3 days. Sampling time for the rainfall-runoff model simulation was suggested as 1 hour. A duration of long-term simulation CSO overflow and frequency calculation should be at least recent 10 year data. A Management plan for the CSOs should be established under a phase-in of the plan. That should reflect site-specific conditions of different catchments, and formalized criteria for defining CSOs should be used to examine the management plans.

• 자원리싸이클링
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• 제29권4호
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• pp.45-50
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• 2020

전기·전자제품 생산업자와 판매업자는 자신이 배포한 장비가 속하는 등급에 해당하는 폐전기·전자제품을 직접 수거하거나 한국전자제품자원순환공제조합에 가입하여 공제조합이 대리할 의무를 이행하도록 할 수 있다. 본 연구에서는 분담금의 요율체계를 검토하고, 파악한 문제점과 이에 대한 개선방안을 제시한다. 첫째, 수집비 및 운반비에 대해 회수유형별 작업을 고려하여 표준작업 및 시간을 설정해야 한다. 둘째, 리사이클링센터의 선별방식에 차이가 있으므로, 이들 방식의 차이와 처리하는 제품군 특성을 반영하여 할당인자에 대한 표준원가를 설정해야 한다. 셋째, 방문수거비 예측모형에서 최소값이 아닌 중앙값 또는 평균값으로 결정하여 충분한 규모의 예산을 확보해야 한다. 본 연구는 공제회원이 공제조합에 납부하는 분담금의 문제점을 살펴보고 이에 대한 개선방안을 제시하였다.

• 한국치위생학회지
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• 제6권4호
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• pp.419-436
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• 2006

PURPOSE: The purpose of this study was to explore dental hygiene treatment fear and anxiety in dental patients. METHODS: The sample consisted of 466 dental patients who had received the dental hygiene treatment at 8 Dental Hospitals and Clinics in Daegu city between March and August 2006 studied. Dental hygienists recruited a questionnaire, which includes generalized anxiety sub-scale(4 items), specific fear sub-scale(5 items), distrust sub-scale(5 items), and catastrophic anxiety sub-scale(4 items). Minimum score is 1, and maximum score is 5. The research was designed to be a cross-sectional measured study. SAS statistical software was used for the analysis. The characteristics of the study sample were described by mean and standard deviation(SD) for continuous variables and by frequency and percentage for categorical variables. The Student's t-test and analysis of variance(ANOVA) were used to compare fear and anxiety score in demographic variables. A Pearson's correlation analysis was conducted for relationship among values of fear and anxiety for dental hygiene. Multiple regression analysis was performed to determine the factors associated with fear and anxiety related with dental hygiene. RESULTS: A total of 466 dental patients were analyzed, their average age${\pm}$SD was $37.7{\pm}12.9$ years(range: 15-79 yr). The mean value for dental hygiene fear and anxiety was 2.70(generalized anxiety 2.65, specific fear 2.93, distrust anxiety 2.72, and catastrophic anxiety 2.42, respectively). There was a statistically significant difference in gender(p<0.05), 2.81 for women was higher than 2.55 for men(p=.0000). The older we are, the higher fear and anxiety for dental hygiene treatment were. that is, under age of 20 years 2.49, 20 years 2.59, 30 years 2.69, 40 years 2.77, 50 years 2.88, 60 years 2.69, and over age of 70 2.45, respectively(p=.0321). Factors related to dental hygiene treatment fear and anxiety by multiple regressions were gender(${\square}$=0.18, p=0.0001), age(${\square}$=.07, p=.0058), and the time when visits dentist recently(${\square}$=.07, p=.0058). CONCLUSIONS: In conclusion, gender, age and the time when visits dentist recently were significantly associated with dental hygiene treatment fear and anxiety. We recommend that further research should investigate a dental hygiene treatment fear and anxiety by using more follow-up study.

• 한국식품위생안전성학회지
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• 제38권3호
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• pp.123-130
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• 2023

본 연구에서는 수산물 시료 중 Salmonella spp. 검출을 위해 단시간의 전배양(2시간 이내)과 탈염과정을 포함한 DNA 추출법을 사용하여 분자생물학적 검출을 위한 수산물 전처리 방법에 대해 연구하였다. 배양 시간에 따른 증균 효율을 탐색하기 위해 10⁰, 10¹ 및 10² CFU/mL농도의 Salmonella spp. 5종을 NB 0.5에 접종하여 증균 전, 1시간 및 2시간 동안의 증균 효율을 비교하였다. 그 결과, 2시간 동안 모든 농도에서 약 1 log CFU/mL가 증균되어 초기 농도와 유의적인 차이가 나타났다. 또한 지역별 패류시료에 S. Typhimurium을 인위적으로 감염시킨 뒤 DNA를 추출하여 염농도를 측정한 결과, 모든 시료의 염농도가 0%로 DNA 추출과 동시에 탈염이 이루어진 것을 확인하였다. 이후 추출한 DNA를 사용하여 PCR을 수행한 결과 모든 시료에서 S. Typhimurium의 특이적 양성밴드가 확인되었다. 다음으로 수산물 시료 중 Salmonella spp. 검출을 위한 증균 과정과 탈염을 포함한 DNA 추출방법의 검증을 위해 멸균 홍합시료 및 비멸균 홍합시료에 Salmonella spp. 5종을 인공적으로 약 10⁰, 10¹, 10² CFU/g의 농도로 오염시켜 전배양과 DNA를 추출하여 PCR로 특이적 증폭 밴드의 여부를 확인한 결과, 모든 농도의 Salmonella spp. 5종에서 특이적 밴드가 확인되었다. 결과적으로 본 연구에서 제시한 전배양 및 DNA 추출방법을 포함한 전처리 방법과 PCR을 사용하여 수산물 시료에서 10 CFU/g 미만의 Salmonella spp.를 검출하였으며, 시간과 비용면에서 효율적이며 과정이 복잡하기 않기 때문에 수산물의 처리 현장에 활용될 수 있을 것으로 기대된다.