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        검색결과 149

        101.
        2022.07 KCI 등재 서비스 종료(열람 제한)
        In this study, the effect of different reaction times for thermal-alkaline pretreatment on the solubilization and biogasification of polyhydroxybutyrate (PHB) were evaluated. Thermal-alkaline pretreatment tests were performed at 73 °C and pH 13 at 0-120 h reaction times. The mesophilic anaerobic batch tests were performed with untreated and pretreated PHB samples. The increase in the pretreatment reaction time results in a 52.8-98.8% increase of the abiotic solubilization efficiency of the PHB samples. The reaction time required to achieve solubilization efficiencies of 50%, 90%, and 95% were 10.5, 52.0, and 89.6 h, respectively. The biogasification of the untreated PHB samples achieved a specific methane production rate of 3.6 mL CH4/g VSS/d and require 101.3 d for complete biogasification. The thermal-alkaline pretreatment significantly improved specific methane production rate (10.2-16.0 time increase), lag time (shortened by 76-81%), and time for complete biogasification (shortened by 21-83%) for the biogasification of the PHB samples when compared to those of the untreated PHB samples. The improvement was higher as the reaction time of the thermal-alkaline pretreatment increased. The findings of this study could be used as a valuable reference for the optimization of the biogasification process in the treatment of PHB wastes.
        102.
        2018.05 서비스 종료(열람 제한)
        석탄은 탄화정도에 따라 고품질의 무연탄 및 역청탄(Hard coal)과 아역청탄과 갈탄(Brown coal)으로 크게 분류한다. 무연탄은 고정탄소 함량(85~95%)과 발열량이 높고 수분함량이 낮아 화력발전소 및 연탄 재료로 활용된다. 하지만 저품위 석탄은 발열량이 4,000~6,000kcal/kg으로 낮고, 수분 함량이 30~70%로 높으며, 산소 관능기가 함유된 탄화수소가 높으므로 자연발화 위험성이 높은 등 많은 단점들 때문에 전체 석탄매장량 중 약 절반가량(45%)이나 되지만 상당량이 채굴되지 않고 남아있다(2007, 세계에너지 위원회). 본 연구에서는 풍부한 매장량을 가진 갈탄 등의 고 수분 저급석탄으로부터 바이오메탄을 생산하고자 생물학적 분해효율을 증가시키기 위하여 펜톤산화 및 고전압펄스(High voltage electrical pulses) 전처리를 수행하였다. 실험을 위하여 호주산 갈탄, 캐나다산 갈탄, 러시아산 이탄을 이용하였으며, 펜톤산화 전처리는 석탄을 1mm이하의 입자로 분쇄하여 H2O2/Fe2+비를 75%, 30, 15, 10, 7.5%로 주입하여 120rpm에서 Jar-Tester로 1시간 반응시켰다. 고전압전기충격 전처리는 펜톤산화 전처리실험 조건과 동일하게 시료를 준비하여 고전압 펄스장치를 이용하여 출력전압 40kV에서 15분간 처리하였다. 전처리를 끝낸 시료는 용액의 SCOD와 석탄의 처리 전, 후의 표면분석과 화학조성 변화를 관찰하기 위하여 적외선 흡수 스펙트럼분석(FT-IR)을 수행하였다. 펜톤산화 처리 후 용액의 SCOD농도변화와 SEM촬영 및 FT-IR 분석결과, 전처리 후의 석탄은 바이오메탄 전환율이 높아질 수 있을 것으로 평가되었다.
        103.
        2018.04 KCI 등재 서비스 종료(열람 제한)
        Background: The demand of recycling renewable agricultural by-products is increasing. Radiation breeding is a method used to improve saccharification efficiency. Thus, we investigated the effect of gamma ray irradiation on the pretreatment and enzymatic hydrolysis of the stalks of Senna tora, an important medicinal plants. Methods and Results: S. tora seeds were irradiated with gamma ray at doses of 100, 200, 300, and 400 Gy. In the pretreated biomass, glucan and lignin content were higher in the M1 (1st generations of irradiation) S. tora stalks than in the M2 (2nd generations of irradiation) stalks, this can be explained by the higher degradation rate in M1. After oxalic acid pretreatment, the concentration of total phenolic compounds (TPCs) in the hydrolysate increased in the gamma ray treated seeds. The highest relative increase rate in crystallinity in the pretreated biomass was observed in M1-400 Gy and M2-100 Gy. The cellulose conversion rate was higher in M1 than in M2, except for 200 Gy. Conclusions: Gamma ray irradiation at an appropriate dose can be used to improve the efficiency of pretreatment and enzymatic hydrolysis, thereby increasing biomass availability.
        105.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to examine the effects of NaOCl, sucrose, and BA concentration as pretreatment solution on quality and vase life of cut flowers in Dendranthema grandiflorum ‘Jinba’. Flower diameter, fresh weight, and vase life in control and 0 mg・L -1 NaOCl treatments decreased, and the treatment with 100~200 mg・L -1 NaOCl was more effective in the quality and vase life. In pretreatment with 2.5% sucrose solution, flower diameter and fresh weight decreased and vase life was shortest due to the rapid leaf wilting. However, pretreatment with 0.1% sucrose solution increased the flower diameter and fresh weight, and showed the longest vase life. When more than 80 mg・L -1 BA was treated with pretreatment solution, flower diameter and fresh weight decreased, and vase life was shortened. With pretreatment of 20 mg・L -1 BA, the flower diameter was bigger than in the other treatments, but it was no effect on fresh weight and vase life. Therefore, it was suggested that pretreatment solution mixed with 200 mg・L -1 NaOCl, 0.1% sucrose, and 20 mg・L -1 BA was the most effective for the quality and vase life of cut flowers in standard chrysanthemum ‘Jinba’.
        108.
        2016.04 KCI 등재 서비스 종료(열람 제한)
        In this study, the COSLIF method for the pretreatment of lignocellulose biomass was employed to overcome the disadvantages of the conventional DA method. When lignocellulose biomass was hydrolyzed by the COSLIF method, dried rice straw produced glucose corresponding to 60.1%, while herbal medicine waste was found in 25.2%. The optimum conditions of the COSLIF method for the pretreatment of biomass were as follows: 84% phosphoric acid, 50oC, and 45 min. The COSLIF method for corn stover showed more lignin-removal characteristics than the DA method. Glucan digestibility in the COSLIF method at a high enzyme dosage was found to be 97% and at least 90% in 12 h and 24 h, respectively, while in the DA method, it was 84% in 72 h. In addition, at a low enzyme dosage, glucan digestibility was 93% in 24 h in the COSLIF method and 60% in 72 h in the DA method. This demonstrates that the COSLIF method is more efficient than the DA method.
        109.
        2016.01 KCI 등재 서비스 종료(열람 제한)
        CT 조영검사 예약환자의 원활한 검사 진행과 조영검사로 인한 부작용을 줄일 수 있는 전처치 프로세스 시스템을 개발 및 적용하여 CT 조영검사 예약환자의 검사 만족도를 높이고자 하였다. 2014년 1월부터 201 4년 2월까지 CT 조영검사를 예약하여 추적검사를 시행했던 2,846명의 환자들 중 예약시간에 검사를 시행 하지 못하고 지연된 214명의 환자들을 대상으로 지연사유를 분석한 후 전처치 프로세스 시스템을 구상 및 개발하여 2015년 1월부터 2015년 2월까지 전처치 프로세스 시스템을 이용하여 전처치가 필요한 644명을 대상으로 SMS 전송 시행율, SMS 전송내역, 예약시간 준수율, 예약시간 지연 사유, 예약 시간보다 지연된 시간 등을 분석하였다. 2014년 1~2월 외래 CT 조영검사 예약환자는 2,846명이었고, 그 중 예약시간에 검사 를 시행하지 못한 환자는 214건으로, 약 7.52%의 비중을 차지하고 있었다. 예약시간보다 지연된 세부적인 사례는 creatinine 미확인이 98건(46%), creatinine 1.3 이상이 40건(19%), 과거조영제부작용이 34건(16%), 금 식 등 전처치 미흡이 25건(11%), 메트포민제제 당뇨약 복용이 4건(2%), 기타 이유가 13건(6%)으로 나타났 으며, 평균 지연시간은 creatinine 미확인이 120분, creatinine 1.3이상이 30분, 과거조영제부작용이 40분, 금식 등 전처치 미흡이 120분, 메트포민제제 당뇨약 복용이 30분, 기타 사유가 60분으로 나타났다. 2015년 1월~2 월 전처치 프로세스 시스템을 적용하여 전처치가 필요한 대상자 644명중 SMS 전송시행율은 515건(80%)으 로 나타났으며, SMS 전송내역을 분석한 결과 당일 검사가 283건(44%), 진료과 방문이 185건(29%), 전처치 불필요가 47건(7%), 외래과에서 전처치 프로세스 시스템 미확인으로 SMS 전송이 안 된 건수가 129(20%)건 으로 나타났다. CT 조영검사 예약시간 준수율은 전체 644건 중 560건(87%)이 예약시간 안에 검사를 시행 하였으며, 예약시간보다 지연된 세부적인 사례는 creatinine 미확인이 23건(28%), creatinine 1.3이상이 11건(1 3%), 과거조영제부작용이 7건(8%), 금식 등 전처치 미흡이 30건(36%), 메트포민제제 당뇨약 복용이 6건( 7%), 기타 이유가 7건(8%) 이었다. 예약시간보다 평균 지연된 시간은 creatinine 미확인이 90분, creatinine 1. 3이상이 20분, 과거조영제부작용이 30분, 금식 등 전처치 미흡이 120분, 메트포민제제 당뇨약 복용이 30분, 기타 사유가 60분으로 나타났다. 조영제 부작용의 효율적인 관리적 측면과 CT 조영검사 예약시간에 검사가 원활하게 진행될 수 있도록 전처치 프로세스 시스템을 적용해본 결과 적용 전에 비해 전처치 준비 시간이 줄어들고 CT실, 진료실, 채 혈실, 주사처치실 등의 방문횟수 및 동선이 줄어들어 CT실을 찾는 고객들의 검사만족도와 의료서비스 향 상에 기여가 될 것으로 사료된다.
        110.
        2015.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        부추를 활용한 가용성 분말 제조에 적합한 공정 개발의 일환으로, 부추원료의 증숙처리 유무와 착즙액의 분무건조 부형제 종류에 따른 분말제품의 품질특성을 조사하였다. 생부추를 세척, 탈수, 절단 후 증숙처리(100℃, 3분)하거나 무처리한 다음 착즙하여 액을 얻고 여기에 부형제로 dextrin(DE=10)이나 β-cyclodextrin를 5% 첨가하고 분무건조하여 분말을 각각 제조하였다. 부추의 증숙처리는 착즙액 분무건조 분말의 L*값은 높게 하였지만 -a*값, b*값, C*값, ho값은 낮게 하는 효과를 보였다. 분말의 수분함량과 수용성지수는 증숙처리와 부형제의 영향을 받지 않았지만, 입자크기는 증숙처리와 dextrin 첨가구에서 가장 적은 것으로 나타났다. 분말의 클로로필, 총페놀, 비타민 C 함량은 증숙처리구보다 무처리구에서 유의적으로 높은 수준을 보였으나 부형제 종류별로는 유의적인 차이를 보이지 않았다. DPPH 유리기 소거능은 증숙처리에 의해 낮아지며 무처리구에서는 β-cyclodextrin 첨가구가 다소 높은 경향을 보였다. 증숙처리구의 관능적 색, 냄새, 종합 기호도는 무증숙처리구보다 유의적으로 높게 평가되었으며 부형제의 영향은 크게 보이지 않았다. 이로써 부추 착즙액의 분무건조 분말의 품질은 착즙 전 증숙처리의 영향을 크게 받는 것으로 확인되었고, 부추 고유의 이화학적 품질 특성유지에는 무처리가, 관능적 기호도를 고려할 경우에는 증숙처리가 유효한 방법으로 판단되었다.
        111.
        2014.09 서비스 종료(열람 제한)
        Chemoresistance is one of the main problems to treat different kinds of cancers or cancer cells. Therefore, it is necessary to find out the strategies to make the cancer cells sensitive to chemotherapy along with optimal dosage of drugs. We examined sensitivity of MCF7 cells through pretreating with an epigenetic modulator, azacytidine (AzaC) to doxorubicin (Dox). The cells were treated with 5 and 10 mM of AzaC for a week, subsequently with 50, 100 and 500 nM of doxorubicin for 24 and 48h. It was found that pretreatment of AzaC significantly enhance the sensitivity of MCF7 cells to Dox, inducing cell death. After 24h 15% cells underwent apoptosis in 500 nM dox treatment group while 23.4% cells death occurred in AzaC pre treatment group. After 48h MCF7 cells treated with Dox showed 19.0% cell death while AzaC sensitized cells showed 50.0% cells death when exposed to 500 nM of Dox for 48h. Western blot analysis showed the upregulations in the expression of bax, caspase-3, caspase-9 and p53 in AzaC-sensitized MCF7 cells treated with Dox as compared to those treated with only Dox. There was no clear indication for pro-apoptosis genes in the cells treated with individual drugs. These results showed that pretreatment with the epigenetic modulator significantly increased the sensitivity of MCF7 cells to Dox. Therefore it is concluded that demethylation event might enhance the activity of DNA intercalating agents to induce DNA damage in breast cancer cells.
        112.
        2014.04 KCI 등재 서비스 종료(열람 제한)
        Anaerobically treated food wastewater still contains high concentration of organic carbon and nitrogen. Consequently,subsequent treatments are needed to meet the effluent criteria of wastewater. Injection of treated food wastewater into awaste landfill body could be one alternative for its subsequent treatment. In this study, preliminary experiments wereconducted to inject treated food wastewater into waste landfill body. Firstly, Biochemical Methane Potential (BMP) testwas conducted to evaluate the methane generation potential of the injected food wastewater. Secondly, anaerobicallytreated food wastewater showed clogging problem during the initial stage of laboratory scale lysimeter injectionexperiment. Accordingly, pretreatments were needed, and we experimented the change of viscosity of the wastewater afterchemical injection (1N acid or base solution) or aeration of wastewater. From the results, BMP for the treated foodwastewater showed 373.8mL CH4/g VS, which was 53% of untreated food wastewater’s. Practically feasible solution toreduce the viscosity of treated food wastewater was 1 day aeration before injection into the waste landfill body.
        113.
        2013.10 KCI 등재 서비스 종료(열람 제한)
        This study was carried out in order to examine the germination characteristics of Atractylodes japonica seeds, and it was to develop the more efficient pre-treatment and production system of the seeds. Experiment was performed by two ways-temperature control (10, 15, 20, 25℃) and shading treatment (full sunlight, 35, 50, 75, 95% of full sunlight). Seed pre-treatment before the each experiment was carried out by temperature (with low temperature and wetting treatment (LTW) for 0, 15, 30, 45 and 60 days) and shading treatment (with drying at room temperature (DRT), drying at low temperature (DLT) and water soaking (WS) for 48 hours). Seeds of A. japonica were germinated well under temperature control (overall 85.3~100%), especially high temperature. And, the seeds pre-treated with LTW for 45 days germinated with a 100% success rate. Under the surveying shading treatment, the highest germination rate was 95.8% with DRT and overall 63.2~95.8%. Germination rate under seeds with WS was 63.2~7.8%. As a result of surveying the whole experiment, A. japonica seeds don't need to pre-treat cause of high germination, but if it is performed with LTW for a certain period of time, it would be more productive.
        114.
        2013.07 KCI 등재 서비스 종료(열람 제한)
        To produce bioethanol from cellulosic biomass, the cellulosic biomass needs pretreatments for high efficiency saccharification. This study, thus, aims to evaluate the efficiency of several pretreatments using vegetables as a cellulosic biomass among food wastes. The evaluated pretreatment methods were acid treatment, ammonia treatment and hydrogen peroxide treatment, which were used by individual and/or incorporating method. As a result, the concentration of reducing sugar increased 4 ~ 15 times and that of glucose increased 5 ~ 26 times compared to the samples without pretreatment. The acid treatment as an individual treatment was the most efficient, and the efficiency of incorporating treatment showed higher than that of individual treatment. Besides, there were differences in the composition and content of hydrolyzed sugars although the saccharification efficiency was similar by the method of each pretreatment.
        115.
        2013.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study was conducted to investigate the effects of pretreatment and different packaging methods on the physicochemical properties of cold vacuum-dried peaches. All the dried peach samples were stored such as N2 gas substitution, vacuum and passive packaged with polyethylene (PE) film and oriented polypropylene (OPP)/aluminum (Al)/PE film at 40℃ for 50 days. The weight change, pH, soluble solids content, titratable acidity, soluble solid-acid ratio (SS/TA), delta E, browning degree and phenolic compounds were analyzed. The weight change and pH were lower in the 0.1% vitamin C-treated group and were significantly lowest in the vacuum-treated OPP/AL/PE. The soluble solids content and the SS/TA were higher in the non-treated groups than in the vitamin C-treated groups. According to the packaging methods, the L* values were higher in the vacuum, N2 gas and passive package, in that order. In addition, the browning degree and the delta E value were lower in the pretreated groups and significantly lowest in the vacuum-treated OPP/AL/PE with 0.1% vitamin C group. The phenolic compounds were high for the pretreated groups, according to the packaging methods (vacuum > N2 gas> passive), and the OPP/AL/PE was significantly higher than the PE. These results suggest that different packaging materials and pretreatment methods affected the quality of the dried peaches, and the vacuum- OPP/AL/PE film packaging group showed a high quality.
        117.
        2013.03 KCI 등재 서비스 종료(열람 제한)
        금정광에 함유된 금, 은 및 유용금속을 효과적으로 용해시키기 위해서 비가시성 금정광을 소성 및 소금소성처리하였다. 이들 소성처리 생성물에 대하여 왕수분해 결과 금, 은 및 유용금속 함량은 비가시성 정광에서보다 소성정광에서, 그리고 소성정광에서 보다 소금소성정광에서 더 많이 용해되었다. 금과 은이 최대로 용해되는 입도는 181~127μm, 750℃의 소성온도, 그리고 20%의 소금첨가량에서였다. XRD 분석을 수행한 결과, 석영과 황철석은 750℃의 소성처리, 그리고 왕수분해에도 불구하고 분해되지 않았다. 황철석은 소금소성처리에 의하여 완전하게 분해되었지만 석영은 파괴되지 않았다. 따라서 석영에 함유된 금은 소금소성처리나 왕수분해를 수행해도 용해되지 않을 것으로 예상된다.
        118.
        2013.01 KCI 등재 서비스 종료(열람 제한)
        The most effective chemical pretreatment method for Scenedesmus dimorphus was evaluated based on solubilization rate and saccharification yield. When 1% of S. dimorphus with 0.5 N of chemicals such as HCl, H2SO4, HNO3, NaOH and KOH was autoclaved at 120oC and 1.1 atm for 60 min, the solubilization rate was high with alkali chemicals while the saccharification yield was low compared to that with acid chemicals. The pretreatment efficiency was significant in order in HNO3, HCl and H2SO4, however, HCl would be effective for field application considering the cost. The proper concentration and time to treat with HCl were concluded in 1 N and 10 min. In the conditions with 1 : 1 mixed acid chemicals such as H2SO4+ HNO3, HCl + HNO3 and HCl + H2SO4, the solubilization rate was similar to that with single acid treatment, while the saccharification yield was enhanced about 34% in the mixed condition with H2SO4 and HNO3 compared to that treated with H2SO4.
        119.
        2012.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study was conducted to determine the effects of the pretreatment and infrared drying methods on the physicochemical properties and antioxidant activities of dried peaches. The pretreatment methods were the 30 min treatment of NaCl, vitamin C, and soluble Ca (1:5 w/v immersion ratio), and leaving them untreated before infrared drying at 55℃ for 20 hr. The moisture content was lower in the pre-treated group and was significantly lowest in the 0.3% NaCl. The titratable acidity and soluble solid content and acid ratio (SS/TA) were high for the vitamin C and soluble Ca groups. The browning degree and cutting strength of the dried peach were lower in the pre-treated group. The total sugar content in the 0.3% NaCl group was significantly higher than those in the vitamin C and soluble Ca groups. The Ca contents were more effective in the soluble Ca treated group and increased with higher Ca concentration. The sensory evaluation results indicated that the organoleptic scores for the overall preference were higher in the 0.1% vitamin C treated group. The phenolic compounds and ABTS radical scavenging ability were high for the 0.1% vitamin C and 0.1% soluble Ca treated groups. These results suggest that pretreatment affected the qualities of the dried peaches, showing that infrared drying can be applied to the production of high quality dried peach products.
        120.
        2012.11 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to improve the analytical method of siloxanes in biogas. Methanol and hexane were tested as absorption solvents of the impinger absorption method, and also the hexane extraction for pretreatment of sample was evaluated. Manufactured gas contained siloxanes of 50 ppm was completely absorbed by the methanol impinger absorption. The absorption efficiency of biogas containing only 2 ppm, however, was maximum 84%. As the condensate on the first impinger increased, the absorption rate of methanol was decreased. The hexane extraction method of the sample was considered to proper the method of moisture removal. The hexane extraction result showed the high recovery factor and the low relative standard deviation. It is suggested that the suitable choice of solvent and pretreatment is required, as the analysis result of siloxane sample may be differentiated depending on the type of biogas or the sampling point.
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