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        검색결과 312

        261.
        2003.09 서비스 종료(열람 제한)
        체외에서 한우 난포란의 감수분열과 배발달 능력의 획득에는 단백질 합성이 수반되어야 한다. 그러나 이러한 변화와 관련된 연구 보고는 거의 전무한 실정이다. 본 실험은 난자의 핵성숙과 관련된 세포질내 단백질 변화를 파악하기 위하여, 체외성숙 시간에 다른 배발달율과 세포질내 단백질을 비교하여 배발달능력 획득과 관련 있는 단백질을 규명하고자 실시하였다. 한우 난소에서 2-8mm의 가시난포로부터 난포란을 회수하였다. 회수된 난포란은 10% FBS와 호르몬이 첨가
        263.
        2002.12 서비스 종료(열람 제한)
        This study was performed to investigate the effect of Perilla frutescens Herba extract on the treatment of chromaticity and colorfastness. Perilla frutescens Herba has been used as a Korean medicine. It is effective in removing dangerous for an unborn child and suppressing pain. It is also good as a detoxification and in treating cold. In the long history of Korea, dyeing has been applied for a means representing the grace of natural and inner esthetic consciousness of man. Vegetable dyes give us such great benefits, diversified color, but no pollution. And ramie fabric has distinctive features such as beautiful brilliance, elegance, and strong durability. So, it is regarded as a special product of Korea traditionally. These studies were carried out to treat with acetate iron, dichloride copper and alum with a mordant to ramie fabric. The ramie fabric was died with Perilla frutescens Herba extract. The results of experiment showed as follows: First, the chromophoric degree was the highest in acetate iron but not distinction in another mordants. Second, the light colorfastness was the highest in non treated and dichloride copper, but alum was the lowest. Third, the discoloration was alum and dichloride copper showed first grade in washing colorfastness. Abrasion colorfastness was not significant in this test. According the previous results, Perilla frutescens Herba has an efficiency in removing skin disorders and suppressing pain. So it considered that Perilla frutescens Herba can be applied effectively to theraphy of detoxification and in treating cold.
        265.
        2000.12 KCI 등재 서비스 종료(열람 제한)
        Before some experiments were carried out with analog bandpass filter which used for filtering the noise included in sound source signal. And this filter was constituted by condenser, register and operational amplifier. Hut these elements made the phase characteristics to differentiate in each sensing channel and cause a little of measurement error. We made new measurement system that was substituted digital filter for the analog filter in order to develop the optimal system which could find the time delay between each sensors with high accuracy. This paper describes the new system's constitution and the function of each parts. Specially three digital filters were designed and applied to the digital signal processing Part. And a series of experiments were carried out with the source's distance 9.53meters and the random bearing interval within the limits of 0˚ ~ 180˚. As a result, we have recognized that the accuracy of measurements were differentiated by the methods what kind of digital filter were adopted. And we have confirmed the facts that IIR LPF was suitable for sound source's bearing measurement and FIR LPF reduced the range measurement error.
        267.
        2000.04 KCI 등재 서비스 종료(열람 제한)
        A kinetic study for anion exchange was performed for commercially available Cl- type anion exchange resin in use to remove nitrate in water. The obtained results from the batch reactor were applied to the Langmuir and Freundlich models. The constants for Langmuir model were qmax=29.82 and b=0.202, and for Freundlich model were K=5.509 and n=1.772. Langmuir model showed better fit than Frendlich model for the experimental results. Ion exchange reaction rate was also calculated and the approximate first-order reaction, rate constant k1 was 0.16 L/㎎·hr. Effective diffusion coefficient was obtained in the range from 9.67×10 exp (-8) to 1.67×10 exp (-6) ㎠/sec for initial concentration change, and from 6.09×10 exp (-7) to 3.98×10 exp (-6) ㎠/sec for reaction temperature change. Activation energy during the diffusion was calculated as 36 ㎉/㏖.
        268.
        1999.12 KCI 등재 서비스 종료(열람 제한)
        This experiment was performed on three parts with prepared coagulants. (1) The characterization of coagulation for PACl coagulants. (2) Comparison of the characterization of coagulation with PAS and PACl coagulants. And (3) Comparison of the characterization of coagulation for the addition of calcium with PACl. Coagulation experiments were conducted with several dosages and pH for each coagulants. For the characterization of coagulation with PACl coagulants, coagulation of Nakdong river waters with three PACls (r=2.0, 2.2, 2.35) showed that the effectiveness of the three coagulants can be considered as r=2.2 > 2.0 > 2.35 which are also the order of higher polymeric aluminum contents. For the comparison of the characterization of coagulation for PAS and PACl coagulants, PAS (r=0.75) coagulants was more effective than other coagulant for the removal of organic matters by sweep floc mechanism with Al(OH)3(s). For comparison of the characterization of coagulation for the addition of calcium with PACl, the presence of divalent cation like Ca2+ was supposed to influence the complex formation of organic anions. From the result of test on coagulation at various pH ranges, the PACl was least affected by the coagulation pH, and the addition of calcium to PACl was very effective for the removal of turbidity and organic materials over broader pH range (pH 4-9).
        269.
        1999.12 KCI 등재 서비스 종료(열람 제한)
        This research explored the feasibility of preparing and utilizing a preformed polymeric solution of Al(Ⅲ) for coagulation in water treatment. Slow base(NaOH) injection into supersaturated aluminum chloride and aluminum sulfate solutions did produce high yields of Al polymers useful to water treatment applications. The method of characterization analysis was based on timed spectrophotometer with ferron as a color developing reagent. The hydrolytic Al species were divided into monomeric(Ala), polymeric(Alb), and precipitate(Alc) from the difference in reaction kinetics. The analysis of PACㅣ's characteristics showed that the quantity of polymeric Al produced at value of r(OHadded/Al) = 2.2 was 83% of the total aluminum in solution, as showing maximum contents and precipitated Al was dramatically increased when r was increased above 2.35. In addition, the characteristics of polyaluminum sulfate (PAS) showed that polymeric Al contained at r = 0.75 was 18% of the total aluminum in solution. The synthesized PACl and PAS were stable during storing period, as indicating negligible aging effect. The effect of sulfate ion on PACl was dependent on the concentration of sulfate ion. That is, polymeric species decrease and precipitate species increase as sulfate ion concentration increased. It can be concluded that the sulfate cause the formation of Al(OH)3(s) at low pH. However, The effect of calcium ion was negligible for distribution of Al species.
        270.
        1999.08 KCI 등재 서비스 종료(열람 제한)
        Removal of Pb(Ⅱ), Cu(Ⅱ), Cr(Ⅲ) and Zn(Ⅱ) ions from aqueous solutions using the adsorption process on domestic loess minerals has been investigated. Variations of contact time, pH, adsorption isotherms and selectivity of coexisting ions and leachate were experimental parameters. YDI, YPT and KRT samples diluted in 1% aquous solution which was adjusted pH 10.8, 8.0 and 6.50, respectively. The result of XRD measurement, Quartz was mainly observed in all samples. In the case of KRT sample, Kaolinite, Feldspar, Chlorite consisting of clay minerals shows almost same pattern with YPT samples. Different properties showed from the YDI sample containing Iillite, remarkably.For all the metals, maximum adsorption was observed at 30min ∼ 60min. Adsorption of metal ions on loess minerals were reached an equilibrium by shaking the solution for about 30min. Removal efficiency of Pb(Ⅱ) ion for KRT, YPT and YDI were 84.7%, 92% and 100%, respectively. The Cu(Ⅱ) and Zn(Ⅱ) adsorptivity on KRT showed the low in various pH solution However, those on YPT and YDI were high than 90% except for the pH 2 solution. The orders of adsorptivities for domestic loess minerals showed as following : YPT>KRT>YDI. The adsorption isotherms of Cu(Ⅱ) and Zn(Ⅱ) ions on clay minerals were fitted to a Freundlich's. Freundlich constants(1/n) of KRT and YPT domestic loess minerals were 0.63, 0.97 and 0.36, 0.25, respectively.
        271.
        1999.04 KCI 등재 서비스 종료(열람 제한)
        Iron hydroxides are good adsorbents for uncomplexed metals, some metal-ligand complexes and many metal oxyanions. However, their adsorption properties of these precipitations are not fully exploited in wastewater treatment operations because of difficulties associated with their separation from the aqueous phase. This study describes experiments in which iron hydroxides were coated onto the surface of ordinary adsorbents(Sea sand) that are very resistant to acids, The coated adsorbents were used in adsorption of oxyanionic metals. The process was successful in removing some anions such as SeO3(-Ⅱ) over a wide range of metal concentrations and sorption of oxyanionic metals increased with decreasing pH. Formation of two surface complexes for oxyanionic metals adsorption on iron hydroxides comprise (1) complexation of the free anion by a positively charged surface site, and (2) protonation of the adsorbed anion (or alternatively adsorption of a protonated form from solution) The coated adsorbents are inexpensive to prepare and could serve as the basis of a useful oxyanionic metal removal.
        272.
        1999.03 KCI 등재 서비스 종료(열람 제한)
        지모의 고품질 품종 육성 및 재배법 개선과 유통중인 생약으로서의 안전성을 위한 품질 평가 기준을 설정하기 위해 지모의 지표성분의 HPLC 분석법을 확립하고자 하였다. 먼저 지모의 유효성분을 분리하고 지표성분화 한 후 HPLC 분석 정량법을 검토하므로써 지모의 품질 분석법을 구명한 결과는 다음과 같다. 지모를 MeOH로 대량 추출하여 계통 추출법으로 용매분배 후 조사포닌 분획인 n-BuOH ext.를 얻었으며 이 n-BuOH ext. 을 silica gel 컬럼 크로마토그래피를 수행하여 화합물 1를 순수 분리 정제하였다. 화합물 1의 1H, 13C NMR spectra 등을 검토한 결과 화합물 1은 지모의 주요 약효성분인 timosaponin A III로 확인되었다. Timosaponin A III은 지모의 주요 성분이자 혈당 강하작용과 항암활성 등의 주요 약효를 보이는 성분으로 지모의 품질 평가 기준으로서 지모의 지표성분으로 하기에 적합하였다. Timosaponin A III의 HPLC 분석법 확립을 위해 ELSD 검출기 가 사용되었으며 ODS계 컬럼을 사용하고 60% acetonitrile를 이동상으로 하여 0.9ml/min의 유속으로 분석을 한 것이 가장 적절한 timosaponin AIII의 HPLC 분석 조건이었다. Timosaponin AIII의 HPLC 분석을 위한 지모 시료의 추출조건 검토에서는 1g 분말시료를 80% MeOH를 추출용매로 할 때 80℃에서 총 2회 환류 추출하는 것이 성분의 총 회수율을 가장 높이는 추출조건이었다.
        273.
        1998.06 KCI 등재 서비스 종료(열람 제한)
        A study was carried our to investigate the characteristics of physico-chemical components palatability of cooked rice accoring to different transplanting time. The treatments were consisted of five transplanting time, from May 5 to July 5 at 15 -day intervals, and six cultivars ; two early-maturing, two mid-maturing and two late-maturing cultivars which are clearly identified by evaluation of cumulative temperature and growth duration from seeding to heading of rice plants. In gelatinization characteristics of rice grain, alkali digestion value was low in the earlier transplanting regardlessof maturing types. Initial pasting temeprature maximum viscosity and breakdown as amylogram charcteristics were high at the transplanting of June 5. The palatability of cookedrice was evaluated that early-maturing cultivars were much better in early transplanting than in late transplanting . The optimum transplanting time for palatibility was the periods from May 5 to 20 in early maturing varieties, May 20 to June 5 in mid-maturing and June 5 to June 20 in late-maturing ones at Honam district in Korea.
        274.
        1998.03 KCI 등재 서비스 종료(열람 제한)
        This study, a sub-one of comprehensive research works titled under "Rural Resources Evaluation System", tried to propose a rational methodology for development of rating tabulation on evaluation items. Firstly, the database system for handling of original/processed data of each evaluation items was constructed, being mainly focussed on the possibilities of data acquisition and statistical treatment. The rating tabulation system developed in the study has the formalized evaluation classes as 2 or 5 for convenience/simplification of analysis works. For each evaluation item in lower step of the goal system, 5 types of rating technique were arranged, which were based on statistical analysis using mean and standard deviation values(Type I), its existence or not(Type II), relative significance of its holding volume(Type III), synthesized weighting scale of its quality and quantity(Type IV), and the others(Type V). And, standardized 4-steps procedure for rating tabulation was proposed. Finally, the rating tabulation system developed in the study was applied to each evaluation item of goal system, from which the numerically-valued ranking criteria was obtained.
        275.
        1997.09 KCI 등재 서비스 종료(열람 제한)
        Many higher fungi of ascomycetes were collected at Mt. Jiri National Park from May to October 1996. They were identified and according to the results, Orbilia, Pezicula, Creopus, and Lasiospheria were new genera to Korea. Dasyscyphus bicolor, Orbilia coccinella, Pezicula acercicla, Mollisia revincta, Hypocera citina, Creopus gelatinosus, Lasiospheria ovina, and Rosellinia thelena were newly to Korea.
        276.
        1997.03 KCI 등재 서비스 종료(열람 제한)
        마 식물체(植物體)를 장일(長日) 및 단일(短日) 조건(條件)으로 일장처리(日長處理)한 각각의 잎으로부터 분리(分離) 정제(精製)한 추출물(抽出物)을 microtuber test로 검정(檢定)하였다. 1. 단일처리(短日處理) 잎에서 얻어진 추출액(抽出液)의 산성(酸性)충과 중성(中性)충의 추출물(抽出物)은 소괴경(小塊莖)의 비대생장(肥大生長)을 촉진(促進)하는 강(强)한 활성(活性)이 인정(認定)되었다. 그리나 장일처리(長日處理) 잎에서는 추출물 활성이 나타나지 않았다. 2. 산성층(酸性層)의 추출물(抽出物)을 활성탄(活性炭) 흡착(吸着) column 으로 정제(精製)하여 각농도의 활성(活性)을 생물검정(生物檢定) (microtuber test)한 결과(結果) 40% 에탈올 용출구의 추출물에서 가장 큰 촉진활성(促進活性)이 나타났다. 3. 포장(圃場)에서 재배(栽培)중인 식물(植物)에서 경시적(經時的)으로 잎을 채취(採取)하여 추출물(抽出物의 활성(活性) 변화(變化)를 검정(檢定)했을 때 괴경(塊莖)의 생장(生長)이 정체(停滯)해 있는 시기(時期)(9월 상순)까지는 활성(活性)이 나타나지 않았으나 9월 중순 이후 활성(活性)이 나타나 10월 상순에는 강한 활성(活性)이 인정(認定)되었다. 이 활성(活性)의 변화(變化)는 괴경(塊莖)의 비대생장(肥大生長) 패턴과 거의 일치(一致)했다. 4. 단일처리(短日處理)한 일에서 얻어진 산성층(酸性層)의 추출물(抽出物)에 다량(多量)의 JA산이 함유(含有)되어 있는 것이 밝혀졌다. 잎 1kg에 포함된 JA산의 양(量)은 290μg/kg으로 추정(推定)되었다. 이상(以上)의 결과(結果)에서 마 괴경(塊莖)의 비대생장(肥大生長)은 단일조건하(單一條件下)의 엽(葉)에 형성(形成)되어진 생리활성물질(生理活性物質)에 의해 기인(起因)될 가능성(可能性)이 큰 것으로 추정(推定)되었다.
        277.
        1995.10 KCI 등재 서비스 종료(열람 제한)
        The study of flocculation kinetics is of fundamental interest in the field of water treatment, because rational study of the factors affecting the coagulation process should be based on the rate of particle growth. The effect of sulfate on flocculation kinetics were examined using ferric nitrate as a coagulant to coagulate kaolin clay in water under several experimental conditions. Both the particle size distribution data obtained from the AIA and the on-line measurement of turbidity fluctuation by the PDA were used to measure flocculation kinetics. Results show that sulfate ion added to the kaolin suspension played an important role in the flocculation process, not only improving flocculation kinetics at more acidic pH levels but also changing surface charge of particles. The kinetics of flocculation were improved mainly by the enhanced rate and extent of Fe(Ⅲ) precipitation attributed to the addition of sulfate, and thereby, better interparticle collision frequency, but little by the charge reductions resulting from the sulfate addition. The increase in sulfate concentration beyond 3×10 exp (-4)M (up to 2×10 exp (-3)M) did not induce further improvement in flocculation kinetics, although the higher concentrations of sulfate ion substantially increased the negative ZP value of particles.
        278.
        1995.06 KCI 등재 서비스 종료(열람 제한)
        Flocculation kinetics using ferric nitrate as a coagulant to coagulate kaolin clay in water was examined as a tool to investigate the effect of low temperature under tightly controlled treatment conditions. Both the particle size distribution data obtained from Automatic Image Analysis (AIA) system and the on-line measurement of the degree of turbidity fluctuation in a flowing suspension by Photometric Dispersion Analyzer (PDA) were used to measure flocculation kinetics. Results show that cold water temperature had a pronounced detrimental effect on flocculation kinetics. For improving flocculation kinetics at low water temperature, maintaining constant pOH to adjust water chemistry for temperature changes was found to be partially effective only in the more acidic pH range studied.
        279.
        1994.11 KCI 등재 서비스 종료(열람 제한)
        The plants medicinal resouces of middle area of Korea were investigated 10 times from May 1, 1993 to November 30. 1994. In order to analyze the vegetation of middle wild plants structure and distribu-tion. Medical wiId plants of middle southern area consisted of 100 familis, 380 specis in all. Theresources of important herb drugs were Polypodiaceae, Graminae, Liliaceae, Polygonaceae,Ranunculaceae, Brassicaceae, Rosaceae, Fabaceae, Apiaceae, Labiatae, Solanaceae, Scrophulariaceae,Campanulaceae, Compositae. The herb drugs were comparatively more than in other mountains in ourcountry.
        280.
        1993.12 KCI 등재 서비스 종료(열람 제한)
        A mathematical model for organic removal efficiency was investigated in a fluidized bed biofilm reactor by changing the feed flow rate, the residence time and the recycle flow rate. In batch experiment, organic removal could be assumed as first order and an intrinsic first order rate constant(kl) was found 6.4 x 10 exp (-6) ㎤/㎎ sec at influent COD range of 3040 - 6620 ㎎/L. In continuous experiment, at the condition of the influent COD, 3040 ㎎/L, the superficial upflow velocity, 0.47 ㎝/sec, the biofilm thickness 336 ㎛ and the biofilm dry density 0.091 g/mL, the calculated COD removal efficiency from the mathematical model gave 60 % which was very close to the observed value of 66 %. As the feed flow rate was increased, the COD removal efficiency was sharply decreased and at constant feed flow rate, the COD removal efficiency was decreased also as the residence time being decreased.