(001) SrTiO3(STO) 기판위에 고온초전도 YBa2Cu3O7-x(YBCO)박막을 이용한 계단형 모서리 임계접합을 제조하였다. STO (100) 단결정 기판위에 계단형 모서리(step-edge)를 제작하기 위한 이온밀링 마스크로 plasma enhanced chemical vapor deposition방법으로 증착된 diamond-like carbon (DLC) 박막을 사용하였고, oxygen reactive ion etch 방법으로 건식식각하였다. 이렇게 제작된 계단형 모서리 기판위에 c-축 수직한 YBCO 박막과 STO박막을 pulsed laser deposition방법으로 에피텍셜하게 증착하였다. 계단의 상층과 하층에서 모두 임계가 형성되었으며 이 접합의 임계온도는 77 K 이상이었고 16K에서 ICRnproducts가 7.5mV, 77 K에서 0.3mV의 값을 나타내었다. 이들 전류-전압 특성은 two noisy resistively shunted Josephson junction 모델을 잘 만족하였다.

본 연구의 목적은 장애물 높이에 따른 상지 팔운동 제한이 스텝안정화(stabilization step)에 영향을 주는지 알아보기 위하여 실시하였다. 연구대상자는 대학생 남자 14명, 여자 16명으로 총 30명이였으며, 평균 연령은 21.5세이었다. 스텝 안정화는 FASTEX(functional activity System for testing and exercise, Cybex Division of Lumex, Inc., USA)를 이용하여 측정하였다.

Ar 이온 식각법을 이용하여 (001) SrTiO3(STO) 단결정 기판 위에 200nm 높이의 계단형 모서리를 제작하였다. 계단식은 입사하는 Ar 이온 빔에 대한 Ar 이온 입사각과 마스크 회전각을 조절함으로써 38˚-70˚의 넓은 범위로 제어할 수 있었다. 초전도 YBa2Cu3O7-δ박막은 계단이 있는 STO 기판 위에 펄스레이저 증착법을 이용하여 증착하였으며, 박막의 두께는 계단 높이에 대한 박막의 두께비가 0.5-1.2가 되도록 하였다. 계단형 모서리 조셉슨 접합의 임계전류밀도와 IcRn값은 77K에서 각각 104A/cm2, 70-200μV이었다.

Bovine oocytes surrounded with compact cumulus cells were cultured for 20 to 22 hours(, 5% ) in modified TCM-199 medium supplemented with 5% superovulated cow serum(SCS) and inseminated by in vitro capacitated spermatozoa. Day 7 to 8 embryos were equilibrated for 10 minutes in 1.3M methyl cellosolve(MC) <1.1M diethylene glycol(DEG), 1.8M ethylene glycol(EG), 1.6M propylene glycol(PG) and 1.1 M 1,3-butylene glycol(BG) solutions. They were then loaded into 0.25ml straws, placed into an alcohol bath freezer at , cooled from to at /minute, seeded, held for 10 minutes, and stored in liquid nitrogen. After thawing in water, the embryos wee rehydrated in TCM-199 medium and then cultured for 48 hours in TCM-199 plus 5% SCS. Embryos were considered viable if they progressed to later developmental stages with a good morphology. Some of the embryos frozen in each cryoprotectant were thawed and transferred non-surgically without removing the cryoprotectant. Hatched embryos survived freezing and one-step dilution as follows : EG(50.0%), MC(53.6%), DEG(56.9%), PG(58.0%) and BG(11.5%). The survival rate of embryos cooled at vs. /minute was not significantly different(P<0.05), however, blastocysts hatched most often (P<0.01) in vitro when cooled at a rate of /minute(64.6%), 31/48) than at /minute(22.6%, 12/53). Pregnancy rates resulting from embryos frozen in the different cryoprotectants were as follows : MC(48%, 10/21); DEG(30%, 3/10); EG(74%, 20/27); and PG(40%, 4/10). These results indicate that MC, DEG, EG and PG have utility as cryoprotectants for the freezing and thawing of IVF Bovine embryos.

Physicochemical and sensory characteristics of Korean traditional alcoholic beverages, such as Kwahaju, Sokokju, Baikhaju, Samhaeju and Hosanchun were investigated during fermentation with the difference of input step and treatment of rice and Nuruk (Korean-style bran koji). pH values in all treatments were similar to be ranged 3.1~3.2, but acidity of the treatment brewed without seed mash was 1.5~2 times higher than that of the treatment brewed with seed mash. The concentration of alcohol in all treatments increased as the concentration of the Nuruk increased. The alcohol concentrations of Samhaeju and Hosanchun ranging from 6.5% to 7.7% were higher than those of Kwahaju, Sokokju and Baikhaju ranging from 7.9% to 10.6%. Residual reducing sugar contents of Kwahaju, Sokokju and Baikhaju ranging from 4.6 g/L to 9.7 g/L were lower than those of Samhaeju and Hosanchun ranging from 14.2 g/L to 15.5 g/L. The consumed total sugar contents of Kwahaju, Sokokju and Baikhaju ranging from 125.4 g/L to 159.2 g/L were higher than those of Samhaeju and Hosanchun ranging from 111.2 g/L to 123.8 g/L, and the treatments brewed with seed mash showed more sugar consumption than the treatments brewed without seed mash. Sensory quality in the treatments brewed with seed mash was better than those of without seed mash. Concentration of Nuruk and preparation of seed mash from it were critical factors compared to input step and treatment of rice in Korean traditional alcoholic beverage brewing.

반도체 소자가 점점 고집적회되고 고성능화되면서 Si 기판 세정 방법은 그 중요성이 더욱 더 커지고 있다. 특히 ULSI급 소자에서는 세정 방법이 소자 생산수율 및 신뢰성에 큰 영향을 끼치고 있다. 본 연구에서는 HF-last 세정에 UV/O3과 SC-1 세정을 삽입하여 그 영향을 관찰하였다. 세정 방법은 HF-last 세정을 기본으로 split 1(piranha+HF), split 2(piranha+UV/O3+HF), split 3(piraha+SC-1+HF), split 4(piranha+(UV/O3+HF) x3회 반복)의 4가지 세정 방법으로 나누어 실험하였다. 세정을 마친 Si 기판은 Total X-Ray Fluorescence Spectroscopy(AFM)을 사용하여 표면거칠기를 측정하였다. 또한 세정류량을 측정하고, Atomic Force Microscopy(AFM)을 사용하여 표면거칠기를 측정하였다. 또한 세정후 250Å의 gate 산화막을 성장시켜 전기적 특성을 측정하였다. UV/O3을 삽입한 split 2와 split 4세정방법이 물리적, 전기적 특성에서 우수한 특성을 나타냈고, SC-1을 삽입한 split 3세정 방법이 표준세정인 split 1세정 방법보다 우수하지 못한 결과를 나타냈다.

본 연구에서는 PET(PentaEthoxy Tanatalum:Ta(OC2H5)5) 유기금속 화합물 전구체를 사용하여 차세대 초고집적회로 제조시 고유전체 물질로 유망한 Ta2O5 박막을 열화학증착 방법에 의하여 증착하였다. 본 증착실험을 통하여 여러 가지 운속기체, 기판온도, 반응압력 등의 공정변수가 층덮힘에 미치는 영향을 고찰하였으며 Monte Carlo 전산모사 결과와 기판온도 변화에 따른 층덮힘 패턴의 변화에 대한 실험결과를 비교하여 부착계수를 산출하였다. 운송기체로는 N2, Ar, He을 바꿔가며 실험하였으며 He>N2>Artns으로 층덮힘이 양호한 것으로 나타났다. 이는 운송기체의 종류에 따라 운동량 확산도, 열 확산도, 물질 확산도 등의 이동현상 특성값들이 다르기 때문이라 생각된다. 기판온도의 증가는 운송기체의 종류에 관계없이 층덮힘을 악화시켰으며 도랑내부에서의 Knudsen 확산과 표면반응물의 탈착에 비해 표면반응이 보다 지배적인 역할을 담당함을 알 수 있었다. 또한 질소를 운송기체로 사용한 경우에 부착계수의 겉보기 활성화 에너지는 15.9Kcal/mol로 나타났다. 그리고 3Torr 이하에서 반응압력이 증가하는 반응압력이 증가하는 경우에는 물질 확산도의 감소 효과 때문에 층덮힘이 악화되었다. 본 연구결과 3Torr, 350˚C에서 He 운송기체를 이용한 경우가 가장 우수한 층덮힘을 얻을 수 있는 최적 공정 조건임을 알 수 있었다.

It is well known that visual cues can improve the motor performance of Parkinsonian patients. Previous laboratory studies have examined the effects of visual cueing to the floor. This case study examined the effects of using a visual cue above eye level on the gait of a Parkinsonian man. It was found that cueing the patient to a target above eye level while waking not only improved the kinematic parameters of the gait cycle but also facilitated a more functional gait pattern with re-intergration of arm swing, rhythm, heel strike and a more erect posture. Visual targeting above eye level may serve as an important clinical tool for physiotherapists treating Parkinsonian patients.

For more than a decade components of low alloy iron powder with nickel and/or molybdenum for general engineering applications have been manufactured from powder metal. In the time to come such PM steel components will gain increasing significance. Because of various manufacturing difficulties they are mostly produced in two separate steps - sintering and hardening - which means high energy and labour requirements. The paper describes how such PM components are produced in just one run through a conveyor belt furnace with automatic atmosphere control and gas quenching zone. Energy and labour costs are low and reproducible quality is exceilent. The mechanical properties obtained with some powder alloys are presented as well.

This study were carried out to investigate the effective concentration of cryoprotectant agents and sucrose by one-step straw method, and to determine the optimum thawing temperature and equilibration time of frozen bovine embryos. The bovine embryos following dehydration by cryoprotective agents and a various concentration of sucrose were directly plunged into liquid nitrogen and thawed in 3O water. Survival rate was defined by FDA test. The results are summarized as follows : 1. The survival rate of bovine embryos thawed after rapid freezing in the freezing medium containing a various kinds of cryoprotective agents added 0.25M and O.50M sucrose were 28.6% and 25.0%, 35.1% and 31.6%, 32.4% and 24.4%, 34.2% and 28.2%, 18.9% and 17.6%, 14.7.% and 21.6%, respectively. 2. The survival rate of bovine embryos thawed after rapid freezing in the freezing medium containing a various concentration of sucrose added 1.5M and 2.OM glycerol, i.5M and 2.OM DMSO and 1.5M and 2.OM propanediol were 22.9~37.8%, 2O.7~31. 3%, 19.2~30.0% and 17.2~25.0%, respectively. 3. The temperature thawed at 2 after rapid freezing of bovine embryos resulted in a significantly higher embryos survival rate than did at 3 and 35. 4. The equilibration time on the survival rate of bovine embryos was attained after short period of time(2.5~5 min.) in the freezing medium higher than long period of time (1O~20 min.).

서브마이크론 설계규칙을 갖는 소자의 이층 배선 공정에서 다챔버 장비를 이용한 금속 층간절연막의 공극없는 평탄화를 위하여 PECVD와 O3 ThCVD산화막의 증착시 층덮힘성을 연구하였다. 산화막의 두께가 증가됨에 따라 변화되는 순간단차비의 개념을 도입하여 공극형성의 개시점을 예측할 수 있는 관계식을 모델링하였고, 금속배선간격의 초기 단차비가 다양한 패턴에서 산화막의 두께에 따른 순간 단차비의 변화를 조사하였다. 모델링 검정결과 5˚이하의 re-entrant각을 갖는 TEOS에 의한 PECVO 산화막의 순간단차비가 모델링에 잘 일치하였다. 공극없는 평탄화는 제1층의 PECVD 산화막의 순간 단차비를 0.8이하로 유지하거나 Ar sputter식각을 통하여 산화막의 모서리에 경사를 준후 층덮힘성이 우수한 O3 ThCVD산화막을 증착함으로써 가능하였다. O3 ThCVD산화막의 etchback이 non etchback공정에 비하여 via접쪽저항체인에서 높은 수율을 보였으며, via접촉저항은 0.1~0.3Ω/μm2로 나타났다.

This study were carried out to investigate the effective concentration of cryoprotective agents and sucrose by one-step straw method, and to determine the optimum thawing temperature and equilibration time of frozen porcine embryos. The porcine embryos foflowing dehydration by cryoprotective agents and a various concentration of sucrose were directly plunged into liquid nitrogen and thawed in 3 water. Survival rate was defined by FDA test. The results are sunnnarized as follows : 1. The survival rates of porcine embryos after ultrarapid frozen4hawing in the freezing medium with a various concentration of glycerol, DMSO and propanediol added 0.25M sucrose were higher survival rate than those of sucrose concentration of 0.50M. 2. The survival rates of porcine embryos after ultrarapid ftozen4hawing in the freezing medium added 0.25M and 0.SOM sucrose were higher survival rate than those of sucrose concentration of 0.75M and 1.00M. 3. The temperature thawed at 2 and 3 resulted in a significantly higher embryos survival rate after 72 hrs in culture than did at 35. 4. The equilibration time on the survival rate of porcine embryos was attained after short period of time(2.5~5 min.) in the freezing medium higher than long period of time(10~20 min.).

The objective of this experiment was to study some possibilities to simplify freezing, thawing and transfer procedure of one-step straw method comparing with the conventional methods using bovine embryos. The previous work are also designed to investigate the thawing effect by development stage and its quality using the embryos. Results obtained were summarized as follows: 1. A total of 87 embryos from 14 donor cows were frozen-thawed and an average of frozen embryo/donor was 6.2. 2. The survival rates of morula stage(65.4%) were higher than those of blastocyst stage(57.l%) and vice versa in rate of morphological recovery (80% vs 95.4%). However. no significant difference was denoted between them. 3. In difference between the groups of good quality and poor quality. good quality was resulted in a significantly higher embryo survival rate(75%) and recovery rates(95%) than poor quality(P<0.0l). 4. In effects of non-permeable sugar dilution in added to l.0M glycerol. higher survival rates were orderd in sucrose. lactose, raffinose and xylose. But lactose-raffinose, sucrose-trehalose and xylose in added to 2.OM glycerol. 5. The highest survival rates were obtained by direct plunge into the liquid nitrogen with 3.OM concentration both of glycerol and trehalose. 6. The survival rates in vitro condition of one-step and direct plunge methods(75%-87.5%) were significantly higher than those of multiple steps (21.4-52.6%) in in vitro (P<0.0l). However, the results of single-step were critical in comparing to other steps of final pregnant conformation.

There is a need for a method that can effectively remove wastewater containing small-sized particles such as TiO2. In this study, we attempted to remove TiO2 wastewater using electrocoagulation-electroflotation two-step separation. The TiO2 wastewater was effectively removed via batch electrocoagulation-electroflotation separation. However, in the batch process, the simultaneous operation of electrocoagulation and electoflotation was challenging due to the high residual turbidity. In the continuous operation, electrocoagulation and electoflotation reactors were kept separate. The turbidity removal in continuous operation was similar to that in the batch process, nevertheless, the residual Al concentration was high, leading to the conclusion that counterterm ensures against residual Al were necessary.

Shape memory materials are widely used in high-tech industries. Although shape memory polymers have been developed, they have a disadvantage, only unidirectional resilience. Shape memory polymers with bi-directional recovery resilience have been actively studied. In this study, a bidirectional shape memory polyurethane was synthesized using poly(ε-caprolactone) diol, methylene dicyclohexyl diisocyanate, and hydroxyethyl acrylate. The first physical curing occurred between hard segments and hydrogen bondings when the solution was dried. The second curing in acrylate groups was performed by UV exposure. A degree of curing was analyzed by infrared spectroscopy. The shape memory properties of 2 step-cured polyurethanes were investigated as a function of UV curing time.

Step의 높이는 하상재료 입경의 크기와 거의 같은 상관관계가 있으며, 하도경사에 따라 증가하고, 하도 폭과 step 파장은 거의 같은 크기로서 하도경사가 증가하면 step 파장은 감소하는 것으로 분석되었다. 하도 폭과 step 폭은 뚜렷한 상관관계가 있으며, 하도 폭의 증가에 따라 step 폭도 증가하는 것으로 분석되었다. 또한, step 파장은 하도 폭에 의하여 규모가 정해지고, step 높이는 step을 형성하는 암석의 크기에 의해 지배되기 때문에 step-pool의 종단면의 하상구조는 하도경사에 따라 변화하는 것으로 판단된다. Pool의 규모는 하도 폭, 입경 및 하도경사와 상관성이 큰 것을 확인하였다. 따라서 하천의 step-pool 구조 특성은 다양한 인자들의 영향을 받지만 대표적으로 입경, 하도 폭 및 하도경사로서 설명할 수 있는 것으로 분석되었다.

최근 들어 보의 환경적인 측면을 고려한 저낙차형 구조물 설치가 요구되면서 고정보의 형태도 다양하게 제안되고 있다. 그러나 실무에 적용하기 위한 횡단구조물의 설계 가이드라인은 매우 한정적이다. 따라서 본 연구는 국내 중소하천에 설치된 고정보의 물리적 제원 변경에 의한 수리적 특 성을 분석함으로써 환경적인 측면을 고려한 저낙차형 고정보의 유량계수 산정을 위한 기초자료를 제공하는데 목적이 있다. 이를 위해 경사형 및 계 단형 보에 대해 crest 변화에 따른 기본적인 유량계수를 도출하였으며 수위-유량 관계 곡선을 개발하였다. 또한 유량과 crest 등과 같은 수리학적 조건을 변화시켜 자유 흐름 조건 및 잠긴 흐름 조건의 흐름특성을 분석하였다.