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        검색결과 85

        41.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In general, water treatment sludge (WTS) had high concentration of heavy metal, thus it made the reuse or recycling of WTS difficult. The optimal solidification conditions for maximum suppression of heavy metal elution from WTS were decided in this study. Under the optimal solidification conditions (i.e., temperature, 320℃; ratio of WTS and MgO, 9:1; solidification time, 1hr), all of heavy metal including aluminum were not detected. Therefore there are no problems for reuse or recycling of WTS which was solidified under the optimal solidification conditions found in the study.
        4,000원
        42.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Copolymers (HSA-98-20, HSA-98-0, HSA-98+20) which are acrylic resin containing 80% solid content were synthesized by the reaction of monomers, including methyl methacrylate, n-butyl acrylate, and 2-hydroxyethyl acrylate with a functional monomer, such as acetoacetoxyethyl methacrylate (AAEM), which may improve in cross-linking density and physical properties of films. The physical properties of prepared acrylic resins, containing AAEM, are as follows : viscosity, 1420~5760cps ; number average molecular weight, 2080~2300 ; polydispersity index, 2.07~2.19 ; conversions, 88~93%, respectively. To prepare acryl resins, four kinds of initiators including α,α'-azobisisobutyronitirile (AIBN), di-tert-butyl peroxide (DTBP), t-amylperoxy-2-ethyl hexanoate (APEH), benzoyl peroxide (BPO) were used. The viscosity of the acrylic resins prepared with these initiators was increased in the order of DTBP〉APEH〉AIBN〉BPO. APEH was proved as a suitable initiator in this study. Shear rates of acrylic resins were constant in respect to viscosity. From these results, it would appear that the resins have Newtonian flow characteristics and good workability.
        4,000원
        43.
        2005.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was focused on the maximization of flame-retardancy of polyesters by a synergism of simultaneously introduced chlorine and phosphorus into polymer chains of modified polyesters. To prepare modified polyesters, reaction intermediates, TD-adduct (prepared from trimethylolpropane /2,4-dichlorobenzoic acid (2,4-DCBA)) and TMBO (prepared from tetramethlene bis (orthophosphate)), were prepared first, then condensation polymerization of the prepared intermediates, adipic acid, and 1,4-butanediol were carried out. In the condensation polymerization, the content of phosphorus was fixed to be 2wt%, and the content of 2,4-DCBA that provides chlorine component was varied to be 10, 20, and 30wt%, and we designated the prepared modified polyesters containing chlorine and phosphorus as ABTTs. The prepared intermediates and modified polyesters were characterized with FT-IR, NMR, GPC, and TGA analysis. Average molecular weight and polydipersity index of the preparation of ABTTs were decreased with increasing 2,4-DCBA content because of the incease in hydroxyl group that retards reaction. We found that the thermal stability of the prepared ABTTs increased with chlorine content at high temperatures.
        4,500원
        44.
        2005.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper presents applicability of Fenton oxidation to perchloroethylene(PCE) contaminated soil. The initial concentration of PCE was 187mg/kg and Fenton oxidation conditions were 1.0M H2O2 and 0.5M Fe2+. More than 97% of PCE decomposition and 98% of dechlorination were obtained within 5 hrs. It was found that the decomposition of PCE by Fenton oxidation was followed pseudo first order and its reaction coefficient was 0.78 hr-1. GC-MS and GC-ECD analysis of reaction intermediates confirmed only the presence of trichloroacetic acid(i.e., 1.0% of initial PCE concentration). Under Fenton oxidation conditions, it was proposed that PCE was decomposed not simultaneously but one by one.
        4,000원
        45.
        2005.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Room temperature cure type of acryl-urethane coatings with high solid content were prepared in this study. Acrylic resins with 80% solid content were cured with hexamethylene diisocyanate (Desmodure N-3600). The cure time of prepared coatings BEHCC-84 (BEHC-84 : Tg=0℃) and BEHCC-87 (BEHC-87 : Tg=30℃), measured by rigid-body pendulum method, was recorded 8.3 hours and 3.8 hours, respectively. Dynamic viscoelastic experiment also revealed the glass transition temperature of BEHCC-84 and BEHCC-87 to be Tg=40.3℃ and Tg=43.3℃, respectively. It was found that the adhesion and flexural properties among various propeties of coatings were enhanced by the incorporation of caprolactone acrylate monomer into the acrylic resins.
        4,000원
        46.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ethanol washing with distillation as a cleanup process of polycyclic aromatic hydrocarbon(PAH)-contaminated soil was investigated in this study. A multistage ethanol washing with distillation process was applied to three different types of soil, i.e., sandy soil, alluvial soil, and clay with the initial concentration of benzo(a)pyrene 10 mg/kg, benz(a)anthracene 250 mg/kg, and pyrene 100 mg/kg soil. Ethanol was selected as washing solvent because of its high PAH removal efficiency, low cost, and non-toxicity comparing to the other solvent such as isopropyl alcohol and sodium dodecyl sulfate. The satisfactory results (i.e. lower than benzo(a)pyrene 1 mg/kg, pyrene 10 mg/kg, benz(a)anthracene 25 mg/kg, which are the Canada or the Netherlands soil standard) for three types of soils were obtained by at most five-six times washing. It was suggested that organic content in soil decreased the removal efficiency by ethanol washing.
        4,000원
        47.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, hetero-electrode structures have been fabricated to increase luminescence efficiency. The presence of a thin layer of Sn or Ag at the organic-aluminum interface enhanced both electron injection efficiency and electroluminescence when compared to OLEDs using homogeneous electrode. In this paper, the effect of the cathode using Sn/Al hetero electrode structure is observed. Electric properties of the OLED using Sn/Al hetero cathode are improved in comparison of only Al cathode. The hetero-electrode existing different energy level induces the advanced structure of OLED can accumulate electron density. The luminescence efficiency of OLED with Sn/Al of Ag/Al cathode is higher because of their higher electron injection efficiency. And, the turn on voltage of the OLED device using Sn thin layer is lowest as about 10 V.
        4,000원
        48.
        2003.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        두부, 콩나물, 된장에서 유전자재조합 대두의 혼입여부를 판별하기 위해 가장 적합한 PCR 프라이머의 선택과 생산 고정에서 물리?화학적인 변성을 재조합 DNA의 손실정도를 공정단계별로 비교 분석하였다. 내재유전자인 β-actin은 600, 495, 250, 160bp을 비교한 결과 160bp에서 가장 광범위하게 검출되었으며, 35S promotor는 130bp, NOS terminator 132bp의 작은 사이즈 프라이머가 유효하였다. 가공공정별로 유전자의 손실정도를 팡가한 결과 두부는 대부분 DNA가 잘 보존되어 가공공정에 따른 DNA의 손실은 거의 관찰되지 않았다. 콩나물은 대부분의 DNA가 발아직후 줄기로 이동하여 적절한 분석부위는 줄기로 판단되었으며, 된장은 효소의 작용에 의하여 유통기간내에 DNA의 검출차이를 보였다. 20일 후 삽입유전자는 소실되었고 특히 50일 이후에는 대부분의 내재유전자 뿐만 아니라 분해되어 검출이 어려운 것으로 판단되어다. 가공처리조건인 열에 의한 DNA의 변성은 100℃에서 40분간 가열하여도 DNA의 손실되지 않고 보존됨을 알 수 있었다.
        4,000원
        49.
        2003.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Neogrammarian regularity hypothesis represents the phonetically gradual, lexically abrupt sound change. Lexical diffusion, on the contrary, supposes the phonetically abrupt, lexically gradual sound change. According to Labov, neogrammarian change type and lexical diffusion change type coexist in sound change, so these two seemingly oppositional theories, in fact, mutually complementary. In this respect, lexical diffusion contributed to the study of sound change by fundamentally broadening its horizons.
        4,900원
        50.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PCR법은 특정 유전자를 증폭하는 기술로 작물 및 식품에서 유전자 변형체 함유 여부를 가리는 효과적인 방법이다. 그러나 핵산의 추출법에 따라 PCR의 감도가 크게 달라지므로 정확한 추출법의 선정이 매우 중요하다. 본 연구는 현재 컬럼형 상용화 키트와 기존의 용매 추출방법을 이용하여 콩과 옥수수가공식품에 대한 각 유전자 부위의 검출감도를 비교 분석하였다. 핵산의 추출효율과 도입유전자의 증폭효율면 모두 상용화 키트인 Wizard™, DNeasy™ 추출법이 우수하였다. DNeasy법은 대부분의 식품에서 우수한 추출효율을 보였으나, 옥수수가공식품에서 수율이 감소하는 단점을 나타내었다. Wizard법은 모든 가공식품에서 고른 추출효율을 보였으며, PCR반응에 의한 증폭산물도 잘 보존되어 가공식품의 GMO검출에 적합한 것으로 나타났다. 한편 CTAB법은 콩가공식품에서 약간 효율이 좋은 것으로 나타났으나 대부분의 경우 효율이 낮았으며, 식품의 종류에 따라 편차가 심하게 나타났다. pheno/chloroform법은 대부분의 식품에서 핵산의 분리가 어려운 방법으로 나타나 GMO분석에는 적합하지 않은 방법으로 확인되었다.
        4,000원
        51.
        2002.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1999년 6월부터 2002년 4월까지 총 2년 11개월 간 전국에서 발생한 소 유조사산에 대한 임상학적 연구결과는 다음과 같았다. 1. 계절별 소 유조사산 발생은 여름에 다른 계절에 비해 많이 발생하였다. 이는 여름철의 고온 다습한 기후와 낮은 우군관리 집중도에 기인한다고 사료된다. 2. 임신우의 산차별 유조사산 발생 비율을 조사한 결과 산차가 낮은 소에서 많이 발생하였다. 이는 유조사산의 원인이 임신우의 산차수에 있기보다는 산차수가 높은경우 사육되는
        4,000원
        52.
        2001.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. In this study, red-sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-4,5-naphthothiazolium(inner salt) with triethyl orthoacetate in the presence of triethylamine. The product was identified by using various analytical tools such as Elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, Mass spectrometer, 1H-NMR spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 573nm. Therefore, it was concluded that naphthothiazolo carbocyanine dye can be used as red0sensitizing dye for the spectral sensitization of photographic emulsion.
        4,000원
        53.
        2001.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A survey was conducted to investigate consumers' attitudes toward the foods developed by gene recombination techniques from December, 1999 to April, 2000. The questionnaires were mailed to 1,500 people, and the 1,101 people responded. The consumers were asked about knowledge, acceptance, intention of purchasing, and labeling information. Although the portion of the consumers (88.8%) knowing the genetically modified foods (GMF) was lower than that of the food expert group (98.7%), many consumers had some knowledge on the GMF, which may be influenced by news released from mass media. Seventy-nine percent of the consumers responded that gene recombination technology is necessary in food production, which is similar to the findings on the survey of the expert group. The portion of the consumers responding that these foods are potentially hazard was 88.1 %, which is a little higher than the data (80.9%) from the expert group. The consumers having greater knowledge less worried about a potential hazard of the gene recombinant foods (p<0.01). Although 62.9% of the consumers responded to be willing to purchase those foods, only 16.2% of them responded to purchase the foods with no conditions, which is lower to that from the expert group (23.5%). There was no statistically significant relationship between the knowledge and the intention of purchasing. The ninety point three percent of the consumers wanted the information on gene recombination to be labeled on the foods. The data from this survey suggest that knowledge of the consumers on the GMF are not accurate, so proper strategy for consumer education may need to be developed. In addition, it is necessary to improve safety assessment sys0etn and analytical techniques for genetically modified foods (GMF) and to build pre- and post-market surveillance system for efficient implementation of the GMF labeling.
        4,000원
        54.
        1999.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A survey was conducted to investigate the attitudes of the food specialist to the food developed by gene recombination. The mail survey was distributed to 1,400 food specialists and received 464, a response rate of 33.1%. Respondents were asked about knowledge, concerns of potential hazards, purchasing and labeling of the gene recombination foods. Most respondents (98.7%) have some knowledge on the gene recombination foods. 91.3% of respondents recognized necessity of gene recombination technology. However, they also point out its potential hazards (80.9%). The groups with less knowledge showed their increased worry on the hazard in comparison with ones of having more knowledge(p$lt;0.01). The result indicated that there was negative relationship between knowledge and worry on the gene recombination foods. The groups with more knowledge showed their increased purchasing on gene recombination foods in comparison with ones of having less knowledge(p$lt;0.01). The result indicated that there was positive relationship between their purchase intent for gene recombination foods and knowledge. 68.4% of respondents showed their interest on purchasing the gene recombination foods. In this group, most of them (44.9%) has on condition that low cost (27.0%). In addition, they also have not use the foods for their children (17.9%) if they buy it. Most respondents (85.3%) want labeling on the gene recombination foods.
        4,200원
        55.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Mo(V) di-μ-oxo type [Mo2O4(H2O)2L]Cl2 complexes(L: 4,4'-Diphenyl-2,2'-dipyridyl, 4,4'-Dimethyl-2,2'-dipyridyl, 4,7-Diphenyl-1,10-phenanthroline) have been prepared by the reaction of [Mo2O4(H2O)6]2+ with a series of chelate ligands. These complexes are completed by two terminal oxygens arranged trans to one another and each ligand forms a chelate types. In Mo2O4(H2O)2L two H2O coordinated at trans site of terminal oxgens. The prepared complexes have been characterized by elemental analysis, infrared spectra, electronic spectra, 1H nuclear magnetic resonance spectra, and thermal analysis(TG-DTA). In the potential range -0.00V to -1.00V at scan rate of 50mVs-1, a cathodic peak at -0.83V ~ -0.88V (vs SCE) and an anodic peak at -0.54V ~ -0.88V (vs SCE) have been observed in aquous solution. The ratio of the cathodic to anodic current(Ipc/Ipa) is almost 2, we infer that redox is irreversible as dimer forms broken.
        4,000원
        56.
        1999.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The symmetric benzoxazolo carbocyanine is of industrial importance as green-sensitizing dye in the spectral sensitization of emulsion microcrystals in positive paper and negative film-making. The stability on the solvents of benzoxazolo carbocyanine dye was measured by UV-Vis spectrophotometer, and then all of solvents were stabilized sensitizer. The maximum absorption peak range in methanol, acetonitrile, acetone, DMF, dichloromethane, chloroform solvents was 501nm~511nm. But it was identified that only methanol can be used to photographic emulsion. The photographic characteristics have contrast of 2.8, speed of 50-55(lux·sec)-1, fog of 0.07-0.08, respectively.
        4,000원
        57.
        1999.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A survey was conducted to investigate the attitudes of public officials related to food hygiene toward food safety. The official groups were divided into four sub-groups based on their area, agency, gender and age. Response of each group to the survey was statistically analysed. The survey's results showed that most of them (87.0%) were satisfied with a domestic level of food hygiene. But, some of them (29.8%) considered unsatisfactoryly on safety of the food they eat. Their response to food safety did not statistically significant between each group of area, agency and age but, in case of gender, female group showed stastically more negative attitude to food safety than male one (P$lt;0.05). All groups chose residues of chemical substances such as pesticides and food additives as the most potential food risk factor followed by foodborne pathogens, heavy metals and animal drug residues. The results are not consistent with the scientific judgement. Therefore, more education and information were needed for these groups. They pointed out food manufacturer as a responsible group for poor food hygiene (48.7%). In addition, food manufacture and processing were selected as main business types with the lowest level in the food hygiene but official, working in the area of the central government and Seoul metropolitan city, pointed out food services establishments as the poorest hygiene one (P$lt;0.01). This result suggested that education and information to let mind of responded groups change, working in this part, and governmental financial support are needed to improve hygiene level of food manufacture and processing (70.3%). They also chose HACCP as the most effective way for improving the level of food hygiene followed by Recall, PL (Product Liability), monitoring, labeling and increasing of number of company with good manufacture and processing (GMP).
        4,200원
        58.
        1998.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The hardening test of gelatin with 2,4-dichloro-6-hydroxy-1,3,5-triazine mono sodium salt was studied at pH 5, 7, 8 and about increasing temperature, respectively. The hardener was prepared by the reaction of cyanuric chloride with sodium hydroxide, disodium hydrogenphosphate-12-water and trisodium phosphate-12-water in the presence of water. The product was identified by elemental analyzer. IR spectrophotometer. Novel hardener can be used in photographic emulsion and showed very good hardening effect.
        4,000원
        59.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The symmetric naphthothiazolo carbocyanine is of industrial importance as red-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. The stability on the solvents of naphthothiazolo carbocyanine dye was measured by UV-Vis spectrophotometer, and then all of solvents were stabilized sensitizer. The maximum absorption peak range in various solvents was 600nm~612nm. But it was identified that only methanol can be used to photographic emulsion.
        4,000원
        60.
        1997.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The symmetric naphthothiazolo carbocyanine is of industrial importance as green-sensitizing dye in the spectral sensitization of emulsion microcrystals in negative film-making. In this study, green-sensitizing dye was prepared by the reaction of 2-methyl-3-sulfopropyl-5-phenyl-benzoxazolium(inner salt) with triethyl orthoacetate in the presence of triethylamine. The product was identified by using various analytical tools such as Elemental analyzer, IR spectrophotometer, UV-Vis spectrophotometer, 1H-NMR spectrometer, TGA and DSC. The maximum absorption peak in methanol solvent was 502nm. Therefore, it was concluded that benzoxazolo carbocyanine dye can be used as green-sensitizing dye for the spectral sensitization of photographic emulsion.
        4,000원
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