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        검색결과 22

        2.
        2022.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 하수 재이용을 위한 역삼투막 공정에서 전처리 정밀여과막(MF) 손상에 대한 누출되는 다양한 수 질변화로써 막 손상 검지 방안을 제시하였다. 이를 위하여 역삼투막 유입수질 적합성 평가지표인 SDI (silt density index)를 3에서 5의 범위 내에서 막 손상 시 검지 감도를 정량화하기 위하여 전처리 분리막이 1에서 3가닥 파단에 따라 SDI는 1.92에 서 6.11까지 증가한 결과를 확인할 수 있었다. 일반적으로 3을 기준으로 역삼투막 유입수질로 설정하였을 때 분리막이 3가닥 까지 파단이 되어야만 막 손상 검지가 가능하다는 것을 의미하며 역삼투막의 오염은 잠재적으로 가속화되어 효율을 저하시 킬 수 있다. 또한 이때 누출되는 입자성과 유기물질에 대하여 0.45 μm 이상의 크기만 걸러주는 입자계수는 입도분포별 막 파 단 개수에 따라 일정한 패턴을 확인할 수 없었으며, TOC 농도는 약 2배의 변화패턴으로써 SDI와의 상관관계로써 TOC가 막 손상 수질지표로써 신뢰성이 높은 것으로 확인되었다. 수질분석결과와 더불어 USEPA에서 제시하는 막 손상 검지 방법 중 압력손실시험과 이를 기반으로 LRVDIT 모델의 적합성 평가를 한 결과 막 손상 또는 역삼투막 공정으로 유입되는 막오염물질 을 신속하게 확인할 수 있는 SDI 및 TOC를 포함한 LRVDIT 모니터링과 UCL 설정을 병행해야 한다.
        4,200원
        4.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The impact of sodium hydroxide, which is one of chemicals of clean in place (CIP) for removing membrane fouling, on the PVDF membrane is reviewed with respect to physical/chemical structural change, the permeability affected therefrom. Based on the cleaning concentration applied in membrane water treatment facilities, 10% of accumulated defluorination was confirmed up to 166g.hr/L which reflects the exposure time. However, membrane resistance was confirmed to be reduced by about 10%. Through FT-IR and EDS analysis, reduction of F and change of are confirmed as factors that affect the permeability of membrane. Membrane resistance, which affects permeability, is affected by loss of additives for hydrophilicity, rather than defluorination of PVDF material. Therefore, in order to check membrane degradation degree, an accelerated test by NaOH was carried out, loss of additives was confirmed, and then PVDF inherent characteristic was observed.
        4,000원
        5.
        2018.05 구독 인증기관·개인회원 무료
        다양한 활용용수 생산을 위한 막 소재 및 막여과 공정개발이 고도화됨에 따라 점차적으로 유지관리 측면의 연구개발 필요성이 부각되고 있다. 그 중에서 유지관리 측면의 막 손상 검지와 수명예측은 제도적으로 정립이 미흡한 실정이며, 막여과 공정 운영에서 경제성과 안정성을 고려한 막 손상 검지 기술개발은 막 특성 및 시설규모에 따른 오차보상이 불가피하게 수반되어야 하는 연구이다. 따라서 분리막의 물리/화학적 노출강도에 따른 특성 변화를 관찰하여 내구년한 산정 및 수명예측 알고리즘을 구축하고자 한다. 또한 분리막의 특성과 모듈의 배열에 따라 최적화된 막 손상 검지를 위한 기체-액체 치환율을 기반으로 물리적 한계도출과 병행하여 이를 극복하기 위한 센싱융합 기술을 소개하고자 한다.
        6.
        2017.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        중공사형 정밀여과(MF)와 한외여과(UF)를 포함한 가압식 막여과 시스템은 높은 수준의 병원균 제거 효율로 인해 음용수 처리에 점점 더 많이 사용되고 있다. 그러나 가압식 막여과 시스템에서 분리막의 손상으로 인한 막완결성의 문제가 발생 시 병원체가 유출될 수 있으므로, 효과적인 온라인 또는 오프라인 방식의 막 완결성 모니터링 방법을 통해 수질의 안정성을 보장하여야 한다. 최근 막 완결성 시험 중 하나 인 압력손실시험(pressure decay test, PDT)이 가압식 분리막 모듈을 이용한 음용수 처리 시설에 적용되고 있다. 이 논문에서는 PDT의 기체 주입방법에 따른 세 가지 조건으로 원수 측, 여과수 측, 원수 여과수 양 뱡향 측 세 가지 조건을 선정 후 이에 따른 감지감도를 이론값과 실험값을 적용하여 비교하였다. 실험결과 가압되는 측의 부피와 감도는 반비례함을 확인하였고, 주입부의 반대방향에 부압을 형성 시에도 감도가 증가함을 확인할 수 있다. 즉 막 손상의 감 지감도는 주입되는 부분의 체적이 작아질수록, 분리막을 경계로 유입과 여과 측의 압력차가 클수록 높아짐을 알 수 있었다.
        4,000원
        7.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        내염소성 원생동물인 크립토스포리디움, 지아디아 등 병원성 미생물의 제거에 대한 신뢰성을 확보하기 위해 정수 처리 공정에서 막여과 시스템이 각광받고 있으며, 이러한 신뢰성을 보증하기 위해 막 완결성에 대한 연구가 중요시되고 있다. 막 완결성 시험은 크게 직접법과 간접법으로 분류되는데, 직접법 중 압력기반의 시험은 버블포인트 이론을 근간으로 병원성 미생물의 최소 크기인 3 μm 크기 이상을 감지할 수 있는 감도로 USEPA Guidance Manual에서 제시하고 있다. 간접법은 온라 인 상태에서 연속적인 운전이 가능하다는 점에서 널리 사용되지만, 직접법에 비해 현저히 낮은 막 손상 감지 감도를 가지고 있 으며, 손상 부위를 특정 지을 수 없는 한계가 있기에 이러한 감지 감도를 개선해야 할 필요가 있다. 따라서 본 연구에서는 압 력 손실 시험에 의한 막 완결성 시험을 통해 막 파단 형태별, 파단 개수, 초기설정압력값에 따른 압력손실률과 LRVDIT 신뢰 성 범위를 상호 비교함으로써 막 손상에 따른 감도의 결과를 정량화하여 UCL 기준을 나타내어 비교 평가하였다.
        4,000원
        8.
        2016.10 구독 인증기관·개인회원 무료
        Embryo transfer (ET) has been applied to many species, which also useful tools for genetic improvement in horses. ET enables to produce a multiple foals from one donor mare in the same breeding season. However, there have been no reports describing equine embryo transfer performed in Korea. In the present study, we performed an equine embryo collection and transfer procedure for the first time. We examined the embryo collection and pregnancy, size of embryo during the incubation period after collection, and progesterone (P4) and estradiol-17ß (E2) concentrations in mare’s serum at embryo collection and transfer. A total of 16 donors responded to estrus synchronization; estrus was induced in 12 donors and 4 recipients, and artificial insemination was successful in 10 donors and six blastocysts were collected from donors. Of these blastocysts, we monitored the size of blastocysts for 3 day during incubation and transferred 2 blastocysts to a recipient, with 1 successful pregnancy and foal achieved. The dimensions of equine embryo at day 7 to day 9 were 409 μm, 814 μm and 1,200 μm. The serum P4 and E2 concentrations were 7.91±0.37 ng/μL and 45.45±12.65 ng/μL in the donor mare, and 16.06±3.27 ng/μL and 49.13±10.09 ng/μL in the recipient mare.
        9.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study is to improve safe execution of the management plan in Construction Technology Promotion Act. This research addresses the issue how to prevent the collapse of facilities under construction and after completion, improve the examination system, and execute Improvement of Safety Management Plan. To achieve this goal, research providing insights into understanding the ways in which creating and presenting safety checks and deploying safety training measures effectively is imperative.
        4,000원
        10.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is focused on manganese (Mn(II)) removal by potassium permanganate (KMnO4) in surface water. The effects of bicarbonate on Mn(II) indicated that bicarbonate could remove Mn(II), but it was not effectively. When 0.5 mg/L of Mn(II) was dissolved in tap water, the addition of KMnO4 as much as KMnO4 to Mn(II) ratio is 0.67 satisfied the drinking water regulation for Mn (i.e. 0.05 mg/L), and the main mechanism was oxidation. On the other hand, when the same Mn(II) concentration was dissolved in surface water, the addition of KMnO4, which was the molar ratio of KMnO4/Mn(II) ranged 0.67 to 0.84 was needed for the regulation satisfaction, and the dominant mechanisms were both oxidation and adsorption. Unlike Mn(II) in tap water, the increasing the reaction time increased Mn(II) removal when KMnO4 was overdosed. Finally, the optimum conditions for the removals of 0.5 - 2.0 mg/L Mn(II) in surface water were both KMnO4 to Mn(II) ratio is 0.67 - 0.84 and the reaction time of 15 min. This indicated that the addition of KMnO4 was the one of convenient and effective methods to remove Mn(II).
        4,000원
        11.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        First of all, Fe or/and Mn immobilized granular activated carbons (Fe-GAC, Mn-GAC, (Fe, Mn)-GAC) were synthesized and tested to remove arsenate (As(V)). The results in batch test indicated that Fe-GAC removed As(V) effectively, even though the surface area of Fe-GAC was reduced largely. Moreover, adsorption isotherm test indicated that the experimental data fit well with Langmuir model and the maximum adsorption capacity (qmax) of Fe-GAC for As(V) was 3.49 mg g-1, which was higher than GAC (2.24 mg g-1). In column test, the simulated water, which consisted of As(V), Fe(III), Mn(II) and Ca(II) in tap water, was used. Fe-GAC column with 1 hr of pre-washing time treated As(V) effectively while GAC column removed Fe(III) better than Fe-GAC column. Moreover, the increasing pre-washing time from 1 to 9 hour in Fe-GAC column enhanced Fe(III) removal with little negative impact of As(V) removal. Mostly, the column filled with Fe-GAC and GAC (i.e. the mass ratio of Fe-GAC:GAC = 2:8) showed the higher treatability of both As(V) and Fe(III), even it operated with 1 hr pre-washing time.
        4,200원
        12.
        2013.10 구독 인증기관·개인회원 무료
        Chungbuk province has number of management honey bee(Apis cerana) colonies. A. cerana produce honey, and are pollinators with in agricultural crops and natural environmental ecosystems. Korean Sacbrood Virus(SBV) causes colony collapses of A. cerana Feb. in Korean apiaries from 2009 years. It causes a fatal disease(sacbrood) of honeybee larvae, which fail to pupate, change color and shape, and finally die. We thus conducted a molecular survey of honey bee RNA viruses, Nosema microsporidia, Foul broods and fungal disease(Chalk brood and Stone brood) associated with environmental conditions in apiaries and differential type(Traditional and Modern) of A. cerana hives in Chungbuk province. We found the presence of Israel Acute Paralysis Virus(IAPV), Nosema apis, and Sacbrood virus(SBV) was detected in the tested samples. IAPV were detected from mordern hive. Nosema apis, and Sacbrood virus(SBV) was detected from traditional hives. Our results demonstrate that honey bee RNA viruse(SBV) and N. apis are present in Traditional hives. It can suggest SBV and other disease might be related environment conditions(Type of hives).
        13.
        2013.10 구독 인증기관·개인회원 무료
        This is the first record of endoparasitic Hymenoptera Apanteles galleriae recorded from Apis cerana colonies in Korea. A simple rearing protocol was established to allow the morphology, mating behavior and infestation rate of A galleriae. In total, 55 lesser wax moth fresh cocoons were kept in the tissue culture test plate at room temperature (25.6 ± 1.5˚C, RH 21 ± 3.7%). The females were 3.4 ± 0.3 longer than male 3.3 ± 0.2. The male antenna was longer than females. The copulation lasts 24.4 ± 2.4 seconds. The larvae of A. galleriae were pupated inside the cocoons of lesser wax moth. Ninety percent of adults A. galleriae was successfully emerged from the lesser wax moth cocoons. A. galleriae can be used as bio-logical control in store and in live colonies to control lesser wax moth.
        14.
        2013.10 구독 인증기관·개인회원 무료
        We investigated the duration of laying worker oviposition and egg-laying behavior in three queenless colonies of A. cerana by in situ video recording. Egg load was determined by dissecting laying workers in September 2012. Egg size, length and breadth, shape index and egg elongation were calculated. To determine the number of eggs laid by laying workers per cell at 24, 53, 74, 120 and 171 hours was also monitored. To estimate the number of eggs per cell per week, a small comb was squeezed between two frames. The combs were collected at given hours and weekly to count the number of eggs, respectively. The results showed that the duration of oviposition of laying workers on average was 109.2 ± 67.5 seconds per cell. During oviposition, egg-laying workers showed two types of behaviors, viz; a still phase, where the egg-laying workers did not move, and a recovery phase, where the egg-laying workers vigorously wagged their abdomens after oviposition. The results showed that on average, 4.0 ± 5.1 of worker eggs per cell per week was recorded. The highest number of eggs was recorded at 120 hours compare to at 24, 53, 74 and 171 hours. Three different shapes of the eggs namely oval, elongated long and elongated curve shaped was laid by workers. The results showed that the laying worker carried 1 to 4 mature eggs in her ovaries and may lay from one to four per oviposition. In conclusion, the laying worker shows a still and a recovery phase during and after laying the eggs. The laying workers retain 1 to 4 eggs in their ovaries. The breadth of eggs is strong positive relationships with length. One worker cell can accumulate up to 33 eggs in queenless colonies.
        15.
        2013.10 구독 인증기관·개인회원 무료
        Ovarioles are smooth, gradually widening white tubes with different stages of eggs. The ovarioles were gently removed, and the right and left ovarioles were separated and counted the ovarioles. We observed that the ovaries of laying queens were extended from second abdominal up to fourth abdominal segments. Each ovariole is supplied with tracheae. The tracheae are auriferous types characterized by coating spiracle tubules with permeable cuticle, which may bring the tracheal air into close contact with haemolymph.
        16.
        2013.09 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to compare the effects of the levels of inbreeding on body weight traits between two breed populations, Hanwoo and Korea Brindle cattle. Birth weight (BW), weaning weight (WW), body weight at 6 months of age (W6) and yearling weight (YW). Records of 1,745 calves (1,513 from Hanwoo, and 232 from Korea Brindle calves) were collected from Livestock Research Institutes in Kangwon, Gyeongbuk and Chungbuk provinces. The least squares means (LSM) and their standard errors for BW, WW, W6 and YW were 25.4±0.1 kg, 81.0±1.8 kg, 146.1±3.7 kg and 291.5±2.4 kg, respectively in Hanwoo calves and 22.6±0.3 kg, 79.9±2.3 kg, 137.6±4.6 kg and 249.3±6.6 kg, respectively in Korea Brindle calves. Pedigree data showed that 14.8% (316 out of 2131) of Hanwoo was inbred and the average inbreeding coefficient was 0.0209 (2.09%). Inbreeding coefficients of ten calves out of 316 total inbred Hanwoo calves were 12.5% or higher, whereas those of the other 306 calves were less than 12.5%. In both breeds, calves were divided into three groups of inbreeding classes - highly inbred group(F≥ 0.125), lowly to medially inbred group(0<F<0.125) and no inbred group(F=0). In Korea Brindle calf populations, 12.2% of the calves observed (57 out of 467 calves) were inbred and the average inbreeding coefficient was 0.1367(13.67%). Forty four calves out of 57 inbred Korea Brindle calves had inbreeding coefficients of 12.5% or higher and the other 13 calves had less than 12.5% of inbreeding coefficients. Average inbreeding coefficient and the number of calves with greater than 12.5% inbreeding coefficient were higher in Korea Brindle calf groups than in Hanwoo calf groups. On the average, body weight growth of Korea Brindle calves was slower than that of Hanwoo calves. This would be due to very small breeding population structure of Korea Brindle cattle as compared to Hanwoo cattle, which would lead to rapid increase in inbreeding coefficients in the population. In conclusion, our study suggests that planned mating system is needed to control inbreeding in Korea Brindle population.
        4,000원
        17.
        2013.04 구독 인증기관·개인회원 무료
        We compared the grafting success in total of 107 rearing Apis carana queens cells, to which we grafted 540 larvae. The wax for cups we prepared from A. mellifera and A. cerana wax. The A. cerana wax cups were found that artificial queen cell cups with the internal diameter of 8.0 mm at the mouth and 8.0 mm depth were highly preferred by the bees for rearing of queens from the grafted larvae. From the 210 grafted larvae into A. mellifera wax bees accepted 30 queens cells, only (16.67 %) ; A. cerana wax bees accepted 59 queens cells (33 %) ; plastic cup bees accepted 18 queens cells, only (10 %). In the preference test the grafting success in the A. cerana wax cups were better than in the A. mellifera wax and plastic cup. The results show better acceptance of larvae grafted into the pure A. cerana wax cups for rearing A. cerana queen. A new method for rearing honey bees, A. cerana, in vivo was developed and the effects of royal jelly from A. mellifera. We used royal jelly diluted 50:50 with sterile water (The royal jelly is kept frozen until used). A small amount of royal jelly is placed at the center of each cell cup. Young A. cerana larvae were transferred into the queen cups containing ± 10 ㎍ of the Royal jelly from A. mellifera and A. cerana. The average rates of acceptance were affected significantly due to the royal jelly source in the queen cell cups. It is so workable first to produce pure A. cerana wax for making the queen cups before a beekeeper starts with grafting.
        19.
        2010.09 구독 인증기관 무료, 개인회원 유료
        Nanotechnology is currently receiving considerable attention in various fields of biotechnology. The uptake of nanoparticles by cells for labeling and tracking is a critical process for many biomedical therapeutic applications. However, nanoparticle labeling of porcine hematopoietic cells has not been demonstrated so far. In the present study, silica-coated nanoparticles conjugated with rhodamine B isothiocyanate (SR-RITC) were used to investigate the uptake of nanoparticles by porcine hematopoietic cells. Flow cytometric and confocal microscopic analyses reveled that the cells were efficiently internalized by the silica-coated nanoparticles. Furthermore, biocompatibility tests demonstrated that the SR nanoparticles were not cytotoxic, and they had no impact on proliferation. Our study demonstrates that silica-coated nanoparticles are taken up very rapidly and with high efficiency into porcine hematopoietic cells, with no apparent deleterious effects. Therefore, silica-coated nanoparticles appear to be a promising tool for tracking porcine hematopoietic cells.
        4,000원
        20.
        2008.03 구독 인증기관 무료, 개인회원 유료
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