• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.632-640
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• 2002

The objective of the study was to apply the vibration technique to reduce the viscosity of bonding adhesives and thereby compare the bond strength and resin penetration into dentinal tubules achieved with those gained using the conventional technique. Eighty-eight noncarious extracted human permanent molar teeth were sectioned to remove the coronal enamel and were embedded in 1-inch PVC pipe with acrylic resin. The occlusal surfaces were placed so that the tooth and the embedding medium were at the same level to form one flat surface, and the samples were subsequently polished with silicon carbide abrasive papers. The samples were randomly assigned to 4 groups(n=22). On Group 1 and 2, Single Bond(3M-ESPE, St. Paul, USA) was used, and on Group 3 and 4, One-Step(Bisco Inc., Schaumburg, USA) was used, and each was applied according to its manufacturer's instructions. For Group 2 and Group 4, vibration was applied with ultrasonic scaler for 10 seconds, and the adhesive was light-cured for 10 seconds. Resin composite was condensed on to the prepared surface in two increments using a mold kit(Ultradent Products Inc., USA) and each was light-cured for 40 seconds. After 24 hours in tap water at room temperature the specimens were thermocycled, and shear bond strengths were measured with a universal testing machine(Instron 4465, Canton, USA). To investigate infiltration patterns of the adhesive materials, the surface of specimen was examined with scanning electron microscope. The results were as follows. 1. The shear bond strengths of vibration groups(Group 2, Group 4) were significantly greater than those of the non-vibration groups(Group 1, Group 3)(p<0.05). 2. The shear bond strengths of Single Bond and One-Step were not significantly different (p>0.05). 3. The vibration groups showed greater number of resin tags in tubules and lateral branches under SEM.

• The Korean Journal of Nuclear Medicine
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• v.7 no.2
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• pp.43-46
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• 1973

이 논문(論文)은 1969년(年) 9월(月) 부터 시작된 IAEA, Internal Society of Hematology 후원(後援)인 ICSH(International Committee for Standardization of Haematology 주최로 열린 제5차 ICSH Panel에서 거론된 Ferrokinetics에 관한 몇 가지 문제점을 초록한 것이다. 1973년 11월 19일 IAEA/ICSH는 Ferrokinetics의 수기(手技)상의 문제점에 관한 토론이 있었다. 즉 혈청철(血淸鐵)이나 총철결합능(總鐵詰合能)을 검사용 혈액 채취시마다 매번 측정해야 되는지에 관한 문제, 환자(患者)의 총철결합능(總鐵詰合能)이 낮을 때 $^{59}Fe$를 주사(注射)하기전 직업적 공혈자(供血者)의 혈장(血漿)과 미리 incubation한 후 주어야 하는지의 문제, 검사용 혈액채취시 그 혈액양, 주입하는 방사성동위원소의 양(量), 항응고제(抗凝固劑)로 Heparin 대신 ACD를 사용할 수 있는지 여부, 통상(通常)의 주사기(注射器)를 사용할 때 그 오차를 줄이는 방법에 관한 문제 방사능(放射能) 계측시(計測時) 혈장(血漿) 대신 전혈(全血)을 사용채도 좋은가에 관한 문제점등이 토론되었다. 여기서 대체로 의견이 일치된 점으로는 주입(注入)하는 $^{59}Fe$는 비방사능(比放射能)이 $5{\mu}Ci/{\mu}g$이상일 것, 이의 양(量)은 체중당(體重當) 얼마로 표시할 것, 방사능계측(放射能計測)에 사용되는 혈액(血液)은 반드시 혈장(血漿)으로 통일할 것, 혈청철(血淸鐵)의 측정(測定)에는 첫번째 및 네번째의 검사용 혈액(血液)을 사용할 것, 혈액(血液)채취후 즉시 혈장(血漿)을 분리(分離)하여 보관할 것, 등(等)에 의견을 모았으며 앞으로 이에 관한 상보(詳報)를 마련하기로 하였다.各) 검사(檢査)에서 계산(計算)된 측정치(測定値)에 차이(差異)가 있어 그 결과(結果)의 해석(解釋) 및 비교(比較) 검토(檢討)에 적지않은 난점(難點)이 생겨 표준화(標準化)된 공통적(共通的)인 방법(方法)의 사용(使用)이 중요(重要)하다는 사실(事實)이 인식(認識)되게 되었다. 1966년(年) 호주(濠洲)의 Sydney에서 개최(開催)되었든 제11차(第11次) 국제혈액학회(國際血學會)때 열린 제4차(第4次) International Committee for Standardization in Haematology(ICSH)에서 Diagnostic Applications of Radioisotopes in Haematology에 관(關)한 expert panel을 갖을것을 의결(議決)하여 다음과 같은 12명(名)의 위원(委員)이 결정(決定)되었으며 위원회(委員會)의 의장(議長)에 Dr. Szur, 총무(總務)에 Dr. Glass가 각각(各各) 선임(選任)되었다. 그간(間) 1967년(年) 영경(英京) London에서 첫 회합(會合)이 있은후(後) New York, Vienna(IAEA후원(後援)) Brthesda(NIH후원(後援))에서 전문위원회(專門委員會)를 갖고 적혈구수명측정법(赤血球壽命測定法)에 관(關)한 의견(意見)의 일치(一致)를 보았다. ICSH와 국제혈액학회(國際血學會)에서는 이번에 결정(決定)된 적혈구수명측정법(赤血球壽命測定法)을 널리 소개(紹介)하며, 측정법(測定法)과 얻어진 결과(結果)의 해석(解釋)에 표준화(標準化)를 기(期)할 목적(目的)으로 이에 연관성(聯關性)있는 전문지(專門誌)에 게재(揭載)할 것을 요청(要請) 받었기에 이에 전문(全文)을 소개(紹介)하는 바이다. 이들은 방사성(放射性) chromium 법(法)의 모든 세부적(細部的)인 면(面)을 표준화(標準化)하고 있으며 그간(間) 가장 논란(論難)의 대상(對象)이 되었던,

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.1
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• pp.1-6
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• 1977

Fifteen soils including volcanic ash, acid sulfate and degraded saline soils were investigated for Languir adsorption isotherm of ammonium using $NH_4H_2PO_4$. The results are as follows. Languir adsorption maxima of ammonium (LAMA) ranged from 2.4me/100g soil to 12.3 and the average was 5.3. Initial concentration of 30 to 60 or 40 to 80 ppm(as N) appears to be suitable for LAMA measurement. There were two LAMA in some soils. Difference between adsorption constants (bonding energy) was mostly greater than that between LAMA. LAMA ranged from 9.4% to 72% of cation exchange capacity and average was 47%. It did not show any clear tendency with CEC, pH, organic matter content, base saturation percent, P, K, Ca, Mg, Na and Si. Except volcanic ash soils which were grouped into two groups according to ammonium adsorption LAMA was significantly (r=0.951 at 1%) correlated with adsorption at 200ppm. This single concentration seems suitable for LAMA measurement. Probable mechanism of ammonium adsorption was discussed, in which the associated anions were combined with iron and aluminum and then ammonium was bound to phosphorus. Applicability of Langmuir adsorption isotherm model to the soils under field condition was also discussed.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.8
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• pp.886-891
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• 2005

In this study, a novel bioreactor system using a submerged hollow fiber membrane module (so called hollow fiber membrane bioreactor, HFMB) was applied to investigate feasibility and biodegradation capacity of the system for the treatment of gaseous toluene. First an abiotic test was conducted to determine the mass transfer coefficient, showing the value was similar to that obtained from a diffuser system using fine bubbles. Second, in the presence of toluene-degrading microorganisms, the HFMB was operated at different inlet toluene loading rates of 50, 100, $500\;g/m^3/hr$, and overall removal efficiencies were maintained in the range of $70{\sim}80%$. In addition, elimination capacities(EC) were increased up to $800\;g/m^3/hr$, which was substantially higher than maximum ECs for toluene reported in the biofiltration literature. Consequently, the HFMB was considered as an alternative method over other conventional VOC-treating technologies.

• Economic and Environmental Geology
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• v.49 no.2
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• pp.89-95
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• 2016

Mo isotope, one of highly redox-sensitive isotopes, has been shown to be useful tracers of geochemical processes. Many studies for Mo isotope have documented with the help of recently developed analysis tools, but it has not yet been documented in the Korea. In this study, we introduce two-stage column separation method of Mo using column tube (BioRad PolyPrep(R) column, 10 ml) and anion exchange resin (BioRad Resin AG(R) 1-X8, 200-400 mesh). Mo isotope ratios in the solid SRMs (BHVO-2, SDO-1, PACS-2) and liquid SRM (IAPSO) were measured on MC-ICP-MS (Multi-collector Inductively Coupled Plasma Mass Spectrometer) and then compared with reference Mo isotope ratios. Mo isotope ratios in our study overlap with reference Mo isotope ratios within analytical error.

• Journal of the Korean Society of Hazard Mitigation
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• v.7 no.3
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• pp.19-31
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• 2007

Humidity and strain were estimated for understanding the relation between humidity change by self-desiccation and shrinkage in high-performance concrete with low water binder ratio and containing fly ash and blast furnace slag. Internal humidity change and shrinkage strain were about 10%, 10%, 7%, 11%, 11% and $320{\times}10^{-6}$, $270{\times}10^{-6}$, $231{\times}10^{-6}$, $371{\times}10^{-6}$, $350{\times}10^{-6}$ respectively on OPC30, O30F10, O30F20, O30G40, O30G50 and from the results, fly ash made humidity change and strain decrease but slag increase comparing with ordinary portland cement. Considering only relation internal humidity and shrinkage by self-desiccation, humidity change and shrinkage represented the strong linear relation regardless of mineral admixture. For specifying the relation on internal humidity change and autogenous shrinkage strain, shrinkage model was established which is driven by capillary pressure in pore water and surface energy in hydrates on the assumption of a single network and extended meniscus in pore system of concrete. This model and experimental results had a similar tendency so it would be concluded that the internal humidity change by self-desiccation in HPC originated in small pores less than 20nm, therefore controlling plan on autogenous shrinkage might be focused on surface tension of water and degree of saturation in small pore.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.96-96
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• 1999

CdTe는 일반적으로 광전 소자나 Xtjs 및 λ선 감지 소자로서 많은 연구가 되어지고 있는 물질이다. 특히 적외선 감지 소자로 쓰이고 있는 HgCdTe 물질의 기판으로서도 많은 연구가 진행되고 있다. 이러한 여러 가지 목적으로 사용함에 있어서 CdTe 내에 가지고 있는 여러 가지 불순물에 의한 영향으로 각종 결함밴드들이 형성됨으로서 소자로서의 응용에 많은 지장을 주고 있다. 이러한 이유로 여러 가지 방법으로 불순물 및 결합에 의한 준위에 관한 연구들이 진행되고 있다. 본 실험에서는 MBE 법으로 성장된 In 도핑된 CdTe 박막의 광학적 성질을 관찰하기 위하여 수소화 및 열처리를 하여 PL 법을 이용하여 관찰하여 보앗다. 열처리는 Cd 분위기의 50$0^{\circ}C$에서 5시간 동안 수행하였으며 수소화는 rf plasma 장치를 이용하여 8$0^{\circ}C$에서 50mW/c2의 출력으로 1시간동안 수행하여 주었다. 열처리한 시료의 경우 PL 신호는 갓 성장한 시료와 비교하여 깊은 준위에 관련된 신호들만 변화가 있었을뿐 그리 큰 변화가 있지는 않았다. 그러나 수소화시킨 시료의 경우 전체적으로 피크의 크기가 5배정도 감소하는 것을 볼 수 있었는데 이것은 수소에 의하여 passivation된 효과로 볼 수 있다. 정량적인 passivation 효과를 보기 위하여 온도의존성 PL 측정을 하여 보았다. 측정에서 관측된 (D,h) emission lines의 FWHM을 비교하여 본 결과 FWHM 온도가 증가함에 따라 선형적으로 증가하는 것이 아니라 급격한 증가를 q이는 구간을 관착할 수 있었다. 이것은 CdTe내에 존재하는 전하를 띠고 있는 주게와 받게의 결합의 결과로 나타나는 현상으로 보여진다. 이러한 결과를 통하여 얕은 준위에 있는 주게 불순물의 농도를 계산해 보았고 Hall 측정을 얻은 결과와 비교하여 보았다.판단된다. 따라서 이 기술은 기존의 광소자 제작을 위한 IFVD 방법의 문제점을 해결할 뿐만 아니라 결정 재성장 없이 도일한 기판상에 국부적으로 상이한 bandgap 영역을 만들 수 있기 때문에 광소자 제작에 적극 이용될 수 있다.나지 않았으며 BST 박막에서는 약 1.2V의 C-V이력현상이 보였다.를 이용하였으며, 이온주입후 열처리 온도에 따른 활성화 정도의 관찰을 위하여 4-point probe와 Hall measurement를 이용하였다. 증착된 다결정 SiGe의 두게를 nanospec과 SEM으로 분석한 결과 Gem이 함량이 적을 때는 높은 온도에서의 증착이 더 빠른 증착속도를 나타내었지만, Ge의 함량이 30% 되었을 때는 온도에 관계없이 일정한 것으로 나타났다. XRD 분석을 한 결과 Peak의 위치가 순수한 Si과 순수한 Ge 사이에 존재하는 것으로 나타났으며, ge 함량이 많아짐에 따라 순수한 Ge쪽으로 옮겨가는 경향을 보였다. SEM, ASFM으로 증착한 다결정 SiGe의 morphology 관찰결과 Ge 함량이 높은 박막의 입계가 다결정 Si의 입계에 비해 훨씬 큰 것으로 나타났으며 근 값도 증가하는 것으로 나타났다. 포유동물 세포에 유전자 발현벡터로써 사용할 수 있음으로 post-genomics시대에 다양한 종류의 단백질 기능연구에 맡은 도움이 되리라 기대한다.다양한 기능을 가진 신소재 제조에 있다. 또한 경제적인 측면에서도 고부가 가치의 제품 개발에 따른 새로운 수요 창출과 수익률 향상, 기존의 기능성 안료를 나노(nano)화하여 나노 입자를 제조, 기존의 기능성 안료에 대한 비용 절감 효과등을 유도 할 수 있다. 역시 기술적인 측면에서도 특수소재 개발에 있어 최적의 나노 입자 제어기술 개발 및 나노입자를 기능성 소재로 사용하여 새로운 제품의 제조와 고압 기상 분사기술의 최적화에 의한 기능성 나노 입자 제조 기술을 확립하고 2차 오염 발생원인 유

• Applied Microscopy
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• v.29 no.1
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• pp.105-124
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• 1999

Histological and ultrastructural differentiations of the neuroepithelial cells in the mouse embryo during neurulation were observed. The neural plates and grooves consisted of pseudostratified columnar epithelium in the embryonic day (ED) 8 embryo were developed. In the ED 9 embryo, the neural tube was developed in all body length of embryo except both the cephalic and caudal ends. Secondary neurulation was shown at the tail bud of the ED 10 embryo. In the ED 8 embryo, the primitive streak was shown in the posterior end of the embryonic disc. The neuroepithelium, notochord and mesenchyme were well differentiated in the cephalic and cervical portions. In the ED 9 and 10 embryos, the roof plates of neural tubes were constituted of the closing of the surface ectodermal cells in the hindbrain and the neuroepithelial cells in the spinal cord. The floor plate of neural tube were consisted of the low pseudostratified columnar epithelium. The spinal motor nerve fibers were initially differentiated in the ED 10 embryo. According to the electron density of the cell and the differentiation of tell organelles, the neuroepithelial cells in the ED 9 and 10 embryos were classified into three types: dark, intermediate and light types. All types in the ED 9 embryo were observed but the dark cell in the ED 10 embryo was not done. The free ribosomes and polysomes in all neuroepithelial cells were developed. The RER and lipid droplets in the dark cell and the Golgi complex in the intermediate and light cells were observed. Many microfilaments in the cytoplasmic processes of intermediate cell and the microfilaments and microtubules in the light cell processes were observed to be well differentiated.

• Korean Journal of Heritage: History & Science
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• v.48 no.1
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• pp.148-165
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• 2015

Iron was one of the most influential factors for formation and development of ancient countries. The diffusion of ironware had increased agricultural productivity and brought about military technical revolution. Needless to say, the rise and fall of the countries depended on the possession of stable iron production. Raw materials and fuels are the key factors for mass production of iron and a transportation route is essential to supply the goods. Jungwon area satisfies the three factors. There are many iron manufacture sites such as Jincheon Seokjang-ri Gusan-ri, and Chunju Chilgeum-dong Tangeumdae earthen ramparts in the Jungwon area. In order to study the ancient iron manufacture technique, reconstitution experiment was carried out using restored furnace which was made based on the Jincheon Seokjang-ri B-23 furnace. Some notable results were identified with the experiment as in the followings. Firstly, a roasting process has a connection with the decrease of hardness of the iron ore. Secondly, melting of the blast pipe as well as the formation of product within the furnace had a crucial effect on the cessation of the experiment. Thirdly, reduced iron in various locations within the furnace prove that there was enough reducing environment during the working. Not only melting point but also properties of iron can vary depending on the carbon contents. For the reason, formation of approximate environment in which iron can react to the chalcoal is the most important factor in terms of iron manufacture.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.12
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• pp.1902-1918
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• 1993

Parallel architecture based on the von Neumann computation model has a limitation as a massively parallel architecture due to its inherent drawback of architectural features. The data-flow model of computation has a high programmability in software perspective and high scalability in hardware perspective. However, the practical programming and experimentaion of date-flow architectures are hardly available due to the absence of practical data-flow, we present a programming environment for performing the data-flow computation on conventional parallel machines in general, loosely compled multiprocessor system in particular. We build an emulator for tagged token data-flow architecture on the iPSC/2 hypercube, a loosely coupled multiprocessor system. The emulator is a shallow layer of software executing on an iPSC/2 system, and thus makes the iPSC/2 system work as a data-flow architecture from the programmer`s viewpoint. We implement various numerical and non-numerical algorithm in a data-flow assembler language, and then compare the performance of the program with those of the versions of conventional C language, Consequently, We verify the effectiveness of this programming environment based on the emulator in experimenting the data-flow computation on a conventional parallel machine.