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        검색결과 331

        321.
        1998.02 KCI 등재 서비스 종료(열람 제한)
        The effects of organophosphorus and carbamate pesticides were examined inhibition of the acetylcholinesterase activity in the chicken brain with enzyme - inhibition methods. The acetylcholinesterase activity in chicken brain determined by the Ellman method was 167 μmol/min/g protein. The optimum pH of acetycholinesterase was 8.2. pI_50 of acetycholinesterase by some organophosphorus were 3.80M of phosphorodithioate, 4.04M of phosphorothioate, 6.33M of phosphate, and 6.60M of phosphrothiolate. pI_50 of acetycholinesterase by some carbamates were 5.10M of XMC, 5. 90M of carbofuran, 6.16M of isoprocarb, 6.30M of carbaryl, 6.47M of BPMC, and 6.77M of propoxur. pI_50 of carbamates selected was similar to that of phosphorothioate and phosphate organophosphates
        323.
        1997.12 KCI 등재 서비스 종료(열람 제한)
        High pressure X-ray diffraction study was carried out on a natural FeO(OH)-goethite to investigate its compressibility at room temperature. Energy dispersive X-ray diffraction method was employed using Mao-Bell type diamond anvil cell with Synchrotron Radiation. MgO powder was compressed together with goethite for the high pressure determinations. Bulk modullus was determined to be 147.9 GPa by the Birch-Murnaghan equation of state under assumption of K0' of 4. This value was subjected to compare with its structural analogs and related materials.
        324.
        1997.06 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to investigate the treatment of wastewater from acetaldehyde manufacturing plant by activated sludge process with Micrococcus roseus AW-6, Micrococcus luteus AW-22, Microbacterium lacticum AW-38 and Microbacterium laevaniformans AW-41. The COD_Mn and BOD_5 of the wastewater were 5,260㎎/L and 6,452㎎/L, respectively. pH was 1.85. The main organic component in the wastewater was acetic acid which was contained 67,600㎎/L. Optimum dilution time for activated sludge process was shown 10 times. The specific substrate removal rate(K_e) was 1.95day^-1 and the nonbiodegradable matters(S_n) were 23.2㎎/L. Saturation constant (K_e) and maximum specific growth rate(q_max) were 1,640㎎/L and 2.33day^-1, respectively. Sludge yield coefficient(Y) and endogenous respiration coefficient(K_d) were 0.28㎎ MLVSS/㎎COD and 0.02day^-1, respectively. COD_cr removal efficiency was 91% for 1.95day of hydraulic retention time.
        325.
        1997.06 KCI 등재 서비스 종료(열람 제한)
        the crystal structure of pale green gem-quality olivine from Bisbee mine,Arizona, (Mg1.83Fe0.18)Si0.99O4, a=4.7608(4)a, c=5.9903(6)a, c=5.9903(4)a, V=291.49(1)a, Pbnm, Z=4 has been refined by both single-crystal and Rietveld methods to R(%) indices of 2.20 and 9.07, respectively. Comparison of site occupancies, cell dimensions, atomic coordinations, and interatomic distances/angles obtained from both methods shows that the Rietveld method produces more accurate site scattering values, cell dimension, and atomic positions than the single-crystal method. This indicates that the Rietveld method is a useful technique for the structural characterization and crystal-chemical study of powdered samples of natural minerals and synthetic materials.
        327.
        1996.12 KCI 등재 서비스 종료(열람 제한)
        Early weathering products of anorthosite were investigated by using scanning electron microscopy in order to trace the development of halloysite particles and aggregates. Tiny short tubes or spheres precipitate on the plagioclase surface in the initial stage of weathering and form the compact globular aggregates. With continued growth, several globules are coalesced into wrinkled halloysite aggregates, and short tubes or spheres in globules grow into long tubes forming sheaf-like aggregates. Particle shape of halloysite varies with changing supersaturation degree of weathering solution, and determines the morphology of halloysite aggregates.
        328.
        1996.06 KCI 등재 서비스 종료(열람 제한)
        Polycrystalline ZrH2 in tetragonal crystal system has been compressed in a modified Bassett-type diamond anvil cell up to 36.0 GPa at room temperature. X-ray diffraction data did not indicate any phase transitions at the present pressure range. The pressure dependence of the a-axis, c-axis, c/a and molar volume of ZrH2 was determined at pressures up to 36.0 GPa. Assuming the pressure derivative of the bulk modulus (K0') to be 4.11 from an ultrasonic value on Zr, bulk modulus (K0) was determined to be 160Gpa by fitting the pressure-volume data to the Birch-Murnaghan equation of state. Same sample was heated at 500℃ at the pressure of 9.8 GPa in a modified Sung-type diamond anvil cell. Unloaded and quenched sample revealed that the original tetragonal structure transforms into a hexagonal structured phase with a zero-pressure molar volume change of ~115.5%.
        329.
        1995.06 KCI 등재 서비스 종료(열람 제한)
        회장암에 함유된 흑운모의 풍화작용을 고령토에 함유된 캐올리나이트의 기원과 관련하여 연구하였다. 흑운모는 사장석이나 각섬석 등 다른 모암광물에 비하여 빠른속도로 풍화되어 고령토화 초기에 흑운모/버미큘라이트 혼합층광물, 버미큘라이트로 변질된다. 버미큘라이트는 계속하여 캐올리나이트로 변질되어 최종적으로 원 흑운모 입자에 비하여 크게 팽창된 캐올리나이트의 가상을 고령토 내에 형성한다. 변질 중인 흑운모에서 방출된 K와 Ti는 각각 일라이트와 아나타제로 침전되며 일라이트는 다시 캐올리나이트로 변질된다. 흑운모가 캐올리나이트의 유일한 모물질이라고 할 수 없으나 풍화과정에서 상당산 양의 캐올리나이트의 생성을 유도하여 고령토내 캐올리나이트 함량 증가에 크게 기여하는 것으로 보인다.
        330.
        1992.12 KCI 등재 서비스 종료(열람 제한)
        지구외핵은 순수한 철원소 이외에, 철보다 원자량이 낮은 원소가 상당량 포함되어 있다. 수소도 외핵내에 존재할 가능성이 있는 성분 중의 하나로 인식되고 있다. 따라서, 철수화물에 대한 압력에 따른 수소의 용해도에 대한 연구와 병행하여, 기타 금속수화물에 대한 연구의 확대 또한 중요하다. 수소는 또한 석유의 대체물질로써 그 가능성이 매우 높으며, 금속수화물상태로 수소를 보다 효율적으로 저장할 수 있는 설정구조에 대한 연구 역시 요구된다. 이러한 두가지 이류로, TiH2를 철수화물의 결정구조적 유사물로 선택하여, 고온-고압하에서 특성화 현상을 연구하였다. 결정질 TiH2 분말시료에 대하여 두가지 다른 온도-압력 조건하에서 고온-고압실험이 시해되었다. 이러한 실험 중 하나는 소형 고온 발생장치가 부착된 피스톤-실린더 다이아몬드 앤질기기를 이용하여 압력은 최고 15 GPa 까지, 온도는 500˚에 고정시킨 상태에서 처리한 시료를 상온-상압상태로 변환시켜 X-선 회절실험을 하였다. 이러한 실험에서, 11.3 GPa 압력 이상에서 고온-고압처리한 시료로 부터 사방정계 결정구조를 보이는 비가역성의 새로운 광물상을 발견하였는데 이는 Ti수화물이 고압하에서 안정한 결정 격자구조를 보이는 새로운 것이다. 이 상변이에 따른 몰부피의 변화는 약 10%이다.
        331.
        1984.06 KCI 등재 서비스 종료(열람 제한)
        All over the world, one finds different types of dues, charges and fees imposed for the use of port facilities. The positiion is further confused by the fact that different names are often used for the same charge in different ports and again the same name can be used for different types of charge. For instance, in some places "tonnage" dues can be dues on cargo tonnage and in others are dues on shipping tonnage. Charges made by port authorities can be of two kinds; charges on ships and charges on goods. One of the abiding complaints of all port tariffs is that they are too complicated. The plea is for simplicity and comprehension. The purpose of this study is to elucidate and to criticize principles for guiding port pricing policy.ng policy.
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