Films consisting of a silicon quantum dot superlattice were fabricated by alternating deposition of silicon rich silicon nitride and Si3N4 layers using an rf magnetron co-sputtering system. In order to use the silicon quantum dot super lattice structure for third generation multi junction solar cell applications, it is important to control the dot size. Moreover, silicon quantum dots have to be in a regularly spaced array in the dielectric matrix material for in order to allow for effective carrier transport. In this study, therefore, we fabricated silicon quantum dot superlattice films under various conditions and investigated crystallization behavior of the silicon quantum dot super lattice structure. Fourier transform infrared spectroscopy (FTIR) spectra showed an increased intensity of the 840 cm-1 peak with increasing annealing temperature due to the increase in the number of Si-N bonds. A more conspicuous characteristic of this process is the increased intensity of the 1100 cm-1 peak. This peak was attributed to annealing induced reordering in the films that led to increased Si-N4 bonding. X-ray photoelectron spectroscopy (XPS) analysis showed that peak position was shifted to higher bonding energy as silicon 2p bonding energy changed. This transition is related to the formation of silicon quantum dots. Transmission electron microscopy (TEM) and electron spin resonance (ESR) analysis also confirmed the formation of silicon quantum dots. This study revealed that post annealing at 1100˚C for at least one hour is necessary to precipitate the silicon quantum dots in the SiNx matrix.

Solar cells have been more intensely studied as part of the effort to find alternatives to fossil fuels as power sources.The progression of the first two generations of solar cells has seen a sacrifice of higher efficiency for more economic use ofmaterials. The use of a single junction makes both these types of cells lose power in two major ways: by the non-absorptionof incident light of energy below the band gap; and by the dissipation by heat loss of light energy in excess of the band gap.Therefore, multi junction solar cells have been proposed as a solution to this problem. However, the 1st and 2nd generation solarcells have efficiency limits because a photon makes just one electron-hole pair. Fabrication of all-silicon tandem cells using anSi quantum dot superlattice structure (QD SLS) is one possible suggestion. In this study, an SiOx matrix system was investigatedand analyzed for potential use as an all-silicon multi-junction solar cell. Si quantum dots with a super lattice structure (Si QDSLS) were prepared by alternating deposition of Si rich oxide (SRO; SiOx (x=0.8, 1.12)) and SiO2 layers using RF magnetronco-sputtering and subsequent annealing at temperatures between 800 and 1,100oC under nitrogen ambient. Annealing temperaturesand times affected the formation of Si QDs in the SRO film. Fourier transform infrared spectroscopy (FTIR) spectra and x-rayphotoelectron spectroscopy (XPS) revealed that nanocrystalline Si QDs started to precipitate after annealing at 1,100oC for onehour. Transmission electron microscopy (TEM) images clearly showed SRO/SiO2 SLS and Si QDs formation in each 4, 6, and8nm SRO layer after annealing at 1,100oC for two hours. The systematic investigation of precipitation behavior of Si QDsin SiO2 matrices is presented.

This study was performed with Korean adults to investigate Makgeolli drinking behavior, preference, and perception about Makgeolli and health, as well as Makgeolli complaints and prices. A survey questionnaire was formulated to obtain information on demographic variables, drinking habits, and perceptions about Makgeolli's function, price, and complaints. The questionnaire was distributed to 468 adults living in the capital area. The results are as follows. Makgeolli (16.1%) was third preferred, following Soju (45.1%) and beer (30.7%), and no significant differences were observed by gender and income, but the preference for Makgeolli increased with increasing age (p<0.001). According to the survey, the largest reason both genders drank Makgeolli was that it tastes good. Men preferred Makgeolli for its health effects and cheap price, while women preferred it for the atmosphere while drinking it. Also, older people and those with higher incomes preferred drinking Makgeolli for its health effect rather than its good taste (p<0.001 for each). No significant difference was observed by gender for the question "Do you think that Makgeolli has a health-promoting effect?" Overall, 51% of the subjects gave positive answers and only 5.9% gave negative answers. Significantly, older people and those with a higher income had a higher rate of answering positively to this question. Belching (45.1%) and headache (29.9%) were the most common symptoms among the side effects of drinking Makgeolli. No significant difference was observed by gender or income, but older people had a higher rate of belching and fewer headaches than younger people (p<0.001). Women had a significantly higher rate of perceiving that Makgeolli was cheap than men. Age and income differences did not influence price perception. To the question "What is the ideal price for high quality Makgeolli", 32.1% answered that the present rate (1,000 won) was ideal, and 59.4% answered that a price between 1,000 and 2,000 won was ideal. These results indicate that the high preference for Makgeolli is due to its good taste and health effects. However, belching and headache caused by drinking Makgeolli were the most common complaints and, thus, must be solved. Some opinions indicated that Makgeolli must eliminate its low-quality image, but, according to this survey, most subjects answered that the ideal price of higher-quality Makgeolli should be increased slightly, which would cause price resistance.

아세틸콜린에스터라아제(AChE) 저해제에 의한 아세틸콜린 분해 억제는 알츠하이머 질병의 가장 확실한 치료 방법 중의 하나로 알려져 있다. 본 연구는 최근 웰빙 건강 소재로 각광을 받고 있는 과일과 채소로부터 새로운 AChE 저해제를 개발하여 항치매 식품이나 대체 의약품 생산에 응용하기 위해 과일과 채소로부터 AChE 저해 활성이 우수한 시료를 선별하고, AChE 저해 물질의 추출조건을 최적화하였다. AChE 저해 활성은 호두의 메탄올 추출물에서 72.6%(IC50=14.2㎍)로 가장 높았고, 호두의 AChE 저해 물질은 80% 메탄올로 40℃에서 12시간 동안 처리하였을 때 가장 많이 추출되었다.

본 시험은 섬유질배합사료(TMR)의 에너지 및 단백질 수준이 다를 경우, 비유초기 유산양의 사료섭취량 및 유생산에 미치는 영향을 조사하기 위하여 수행하였다. 시험 동물은 자넨종 생후 16개월령 전후의 초산 착유양 24두를 시험구별 6마리씩 공시하였으며, TMR의 에너지와 단백질 수준은 대조구(Control)가 TDN 67.0%, CP 13.9% (NRC, 2007), 에너지 증량구(T1)는 TDN 73.7%, CP 13.9%, 단백질 증량구(T2)는 T

IPCC (Intergonvernmental Pane1 of Climate Change)에서 CO2의 23,900배에 해당하는 지구온난화지수를 가진 SF6 (Sulphur hexafluoride) 가스와 중전기 산업에서 아크 발생에 의해 생긴 SF6의 주요 분해 부산물 중 하나이며 CO2의 6,300배에 해당하는 지구온난화지수를 가진 CF4 (Tetrafluoromethane) 가스의 배출에 대한 규제가 적극 검토되고 있다. 본 연구는 O2, CF4에 대한 SF6의 분리 회수의 기초 연구로써, 상용화된 PSF (polysulfone), PC (tetra-bromo polycarbonate)와 PI (polyimide) 고분자 분리막을 사용하여 O2, CF4와 SF6 가스의 압력과 온도 변화에 따른 투과도 및 투과선택도 연구를 수행하였다. 압력 변화에 따른 O2의 투과도는 PSF 중공사 분리막에서 압력 1.1 MPa일 때, 37.5 GPU로 가장 높게 나타났고, SF6와 CF4의 경우 압력 1.1 MPa에서 PC 중공사 분리막이 각각 2.7 GPU와 2.5 GPU로 가장 높은 투과플럭스를 나타냈다. 온도 변화에 따른 O2의 투과플럭스는 막의 온도가 45℃일 때 PSF 중공사 분리막이 41.2 GPU로 가장 높게 나타났고, SF6와 CF4는 막의 온도가 25℃일 때, PC 중공사 분리막이 각각 2.4 GPU와 2.3 GPU로 가장 높은 투과플럭스를 나타냈다. 압력과 온도 변화에 따른 O2/SF6와 CF4/SF6의 투과선택도 결과, 높은 단일 기체 투과플럭스를 보인 PSF와 PC 중공사 분리막이 가장 낮은 투과선택도를 나타내고, 가장 낮은 투과플럭스를 보인 PI 중공사 분리막이 가장 높은 투과선택도를 나타냄을 확인할 수 있다.

In the environment of 450mm wafers production known as the next-generation semiconductor production process, one of the most significant features is the full automation over the whole manufacturing processes involved. The full automation system for 450mm

Purpose : In order to verify using Convergence Insufficiency Symptom Survey(CISS) is proper method to distinguish convergence insufficiency(CI) group and normal binocular vision(NBV) group in adults. Methods : 97 subjects 19 to 35 with normal VA and no strabismus participated in this study. Phoria, positive fusional vergence(PFV), nearpoint of convergence(NPC) and accommodation convergence/ accommodation(AC/ A) of 97 were measured. Results : According to criteria, 62 subjects were included in this study and analysed with CISS. Nine subjects had CI and 53 had NBV. General symptoms of CI group were significantly greater occurrence of Jose concentration, tiredness, sleepiness, uncomfort, double vision and blurring in that order. A significant difference between CISS seore of CI subjects (mean±SD: 25.67±7.67) and NBV group(l2.74 ±4.80) were found(p=O.OOO). The area under the ROC curve was 0.955 indicating outstanding discrimination using the CISS. Using seores of 21 or higher to denote CI, a sensitivity of 88.9% and specificity of 98.1% were obtained. Conclusions : The results suggest that the CISS is a valid instrument for differentiating adults with symptomatic CI from those with symptomatic NBV. Adopting score 21 as cutoff value, it is proved that distinguishing Cl from normal is most precise. Additionally, Adults in this age group were able to respond to a broad range of symptom questions associated with CI. It. therefore, demonstrates CISS is a valid preliminary examination to scan CI patient.

Indoor, outdoor, and personal nitrogen dioxide (NO₂) exposures were studied in a population of housewives. Daily Indoor and outdoor NO₂ concentrations were measured and compared with simultaneously personal exposures of 17 housewives for 7 consecutive days in 17 houses. In this study, indoor and outdoor NO₂ samples at home were collected only while the housewives were at home samples. Time activity patterns and house characteristics were used to determine the effects of these factors on personal exposure. Since housewives spent their times in indoor houses with mean of 78.3%, their NO₂ exposures were associated with indoor houses NO₂ levels (r= 0.89) rather than outdoor NO₂ level (r= 0.85). Contribution of indoor NO₂ concentration on personal exposure was estimated by 70.77% by using of mass balance model. The close association between measured indoor NO₂ concentrations and measured personal exposure and contribution of indoor NO₂ concentration suggests that measuring indoor concentrations of NO₂ in the home is sufficient to estimate personal exposure accurately.

Purpose : Many methods of residual astigmatism measurement are available clinically. In this study, residual astigmatism was examined and compared various tests of residual astigmatism measurement. Method : Subjects(54 males, 53 females) without ocular pathology and ocular surgical history were recruited from the college students. Noncycloplegic subjective and objective refraction were performed. And after wearing RGP lenses, objective refraction were performed. Result : The means Jo and J4s components of total astigmatism were +0.26±0.38D and -0.01±0.14D with subjective refraction. +0.29±0.39D and -0.03±0.17D with objective refraction and +0.34±0.51D and - 0.28±0.22D with Javal's rule, respectively, There was significantly difference in three methods measuring total astigmatism(p(O. 05) . Measuring the residual astigmatism with difference between total astigmatism and corneal astigmatism, the means Jo and J4s components of residual astigmatism were - 0.21±0.28D and +0.21±0.18D with subjective refraction, -0.17±0.32D and +0.20±0.17D with objective refraction, -0.13±0.10D and - 0.06± 0.04D with Javal's rule. and there was significantly difference(p(0.05). The means Jo and J4s components of residual astigmatism were - 0.18±0.25D and +0.20±0.16D with rest values reported auto- refractor and - 0,14±0.24D and - 0.06±0,17D after wearing RGP contact lenses. Conclusion : There were individual differences in means and standard deviations of residual astigmatism in each method. Therefore, it is important to consider residual astigmatism with total astigmatism and corneal astigmatism in clinic.

The objective of this study was to determine physiological and mechanical factors effecting on the pregnancy rates following artificial insemination in dairy cattle. Estrus for artificial insemination of cows was checked whether the outflow of mucus from the elements was out flow or not. There were no significant difference of gestation rates with mucus release (31.76%) and without mucus release (24.03%). The pregnancy rates were 39.02% in 10~20mm of follicle size group and 27.08% (p<0.05) in 20~30mm diameter of the follicles. There were not different pregnancy rates between twice inseminated dairy cattle and more than 3 times inseminated cattle. The pregnancy rate was 28.57% under automatic milking system. In contrast, under artificial milking system pregnancy rate was 56.85%. Two systems significantly (p<0.05) were different. These results suggest that pregnancy rates were not effected by physiological system, but mechanical condition.

본 연구는 콘크리트 슬래브 및 포장도로에 덧씌우기 포장으로 개발된 아크릴 폴리머 콘크리트의 물리 역학적 특성을 평가하기 위하여 수행되었다. 점도시험, 흐름시험, 압축강도시험, 휨 강도시험, 인장강도시험, 선 수축시험, 열팽창계수시험 및 온도변화에 대한 부착성 등 다양한 실내 시험을 실시하였다. 본 연구에서 개발된 아크릴 폴리머 콘크리트의 실내시험 결과 ACI에서 제시하는 모든 기준을 만족하는 것으로 평가되었다. 아크릴 폴리머 콘크리트의 공용성을 평가하기 위해 추가적으로 포장가속시험(APT)을 수행하였으나 등가 단축하중을 15,909,939회를 적용하는 동안 심각한 파손을 확인할 수 없었다. 마지막으로 현장 적용성을 평가하기 위하여 열화현상이 진행된 콘크리트 도로에 10mm의 폴리머 콘크리트 덧씌우기를 적용하였다. 현장 적용 후 미끄럼 저항성, 소음 및 평탄성을 측정한 결과 미끄럼 저항성 및 소음도는 상당히 개선되었으나 평탄성 측정치는 다소 증가하였다. 추후 현장에 적용된 아크릴 폴리머 콘크리트의 정기적인 조사를 통하여 장기 공용성 평가를 수행할 예정이다.