• 한국재료학회지
• /
• 제27권1호
• /
• pp.48-52
• /
• 2017

In this study, we used I-V spectroscopy, photoconductivity (PC) yield and internal photoemission (IPE) yield using IPE spectroscopy to characterize the Schottky barrier heights (SBH) at insulator-semiconductor interfaces of Pt/$HfO_2$/p-type Si metal-insulator-semiconductor (MIS) capacitors. The leakage current characteristics of the MIS capacitor were analyzed according to the J-V and C-V curves. The leakage current behavior of the capacitors, which depends on the applied electric field, can be described using the Poole-Frenkel (P-F) emission, trap assisted tunneling (TAT), and direct tunneling (DT) models. The leakage current transport mechanism is controlled by the trap level energy depth of $HfO_2$. In order to further study the SBH and the electronic tunneling mechanism, the internal photoemission (IPE) yield was measured and analyzed. We obtained the SBH values of the Pt/$HfO_2$/p-type Si for use in Fowler plots in the square and cubic root IPE yield spectra curves. At the Pt/$HfO_2$/p-type Si interface, the SBH difference, which depends on the electrical potential, is related to (1) the work function (WF) difference and between the Pt and p-type Si and (2) the sub-gap defect state features (density and energy) in the given dielectric.

• 한국임상수의학회지
• /
• 제29권2호
• /
• pp.173-176
• /
• 2012

6 년령의 수컷 시츄 견이 복부 팽만을 주 호소로 내원하였다. 복부 방사선 검사와 초음파 검사에서 많은 양의 액체를 포함하고 있는 연부조직 밀도의 종괴가 발견되었다. 종괴의 세포학적 검사를 위해 초음파 유도 세침흡인을 실시하였으며, 세포학적 검사 결과 섬유화가 동반된 육아조직이 의심되었다. 종괴의 확인과 수술적 제거를 위해 진단적 개복술을 실시하였다. 개복시 원위 공장부위에 인접한 장간막의 뿌리에서 유래한 종괴가 확인되었고 종괴는 원위공장 부위에 부착되어 있었다. 종괴와 부착 부위의 분리가 어려웠기 때문에 종괴와 부착 부위를 모두 수술적으로 제거하였으며 장문합술을 실시하였다. 종괴의 조직병리학적 검사 결과 저 악성도 점액육종이 진단되었으며, 종양 세포는 알시안 블루 염색에 양성 반응을 보였다. 추가로 실시한 Ki67 항체를 이용한 면역조직화학 염색 결과 Ki-67 지수는 2.5 였다. 환축은 절제술 실시 후 현재까지 30개월 동안 전이와 재발의 증거 없이 살고 있다.

• 기술사
• /
• 제2권6_7호
• /
• pp.12-23
• /
• 1969

The purpose of this study is to find out the reasonable amount of evapo-transpiration required for the paddy rice plant during the whole growing season. So, on the basis of the 3year experimental data concerning the evapo-transpiration from 1966 to 1968, the author obtained the following results. 1) The leaf area index in the densely planted plot is generally higher than that in the conventionally planted one during the first half of growing season. So, the coefficient of transpiration in the former plot is some what higher than in the latter, and the coefficient of water surface evaporation under the plant cover has the inverse relation between both plots. 2) It is unreasonable that coefficient of evapo-transpiration is applied to the calculation of the evapo-transpiration requirments of each growing stage, because a certain degree of variation in meteorological factors and in the thickness of the plant growth is involved in it. 3) It is most reasonable that the rate of transpiration and of the water surface evaporation is applied to the calculation of the transpirated amount and evaporated one in each growing stage because it shows almost constant value in spite of any meteorological conditions in so far as the variety of rice, planted density and control of applying fertilizer are same and the disease and blight are negligible. 4) The ratio of the amount of transpiration to the weight of the whole air dried yields has the tendency of decreasing as that of the yields increase, having almost constant value despite the amount of pan evaporation; and the value is about 210 when the weight of root parts is included to that of the yields. 5) Although the required amount of transpiration during the whole growing season can be calculated with the above ratio, fig. 7 showing the relation between the amount of transpiration and the weight of the yields is more reasonable and will be convinient to find it. And the requirements of water surface evaporation during the same season can also be directly found with the weight of air dried straw refering to fig.8.

• 대한본초학회지
• /
• 제35권5호
• /
• pp.1-12
• /
• 2020

Objectives : Phyllostachys pubescens and Scutellaria baicalensis are considered to be effective in promoting blood circulation in traditional medicine. In this study, we examined whether a mixture of P. pubescens leaves and S. baicalensis root (BS21) had any anti-obesity, anti-hyperlipidemia, or anti-hyperuricemia effects and the possible mechanisms of action. Methods : We examined the effects of BS21 in high-fat diet (HFD)-induced obese mice. Mice were fed HFD with BS21 (75, 150, or 300 mg/kg) or Garcinia cambogia extracts (245 mg/kg) as a positive control for 8 weeks. At the end of 8 weeks, body weight, liver and adipose weight, adipocyte size, plasma lipid profiles, adipokine and uric acid levels, and adipose tissue expression levels in obesity and uric acid production-related genes were examined. Results : BS21 decreased body weight gain, white adipose tissue, liver weight, adipocyte size, and liver triglyceride accumulation. It also reduced levels of plasma glucose, triglycerides, non-esterified fatty acids, total cholesterol, low-density lipoprotein cholesterol, alanine transaminase, leptin, and uric acid. In contrast, BS21 increased adiponectin levels. Furthermore, BS21 decreased the expression levels of adipogenesis-related genes, such as peroxisome proliferator-activated receptor γ, sterol regulatory element binding protein-1c, and fatty acid synthase, as well as xanthine oxidoreductase, which is involved in uric acid production. Conclusions : These results suggest that BS21 may exert anti-obesity, anti-hyperlipidemia, and anti-hyperuricemia effects in HFD-induced obese mice by regulating the expression of xanthine oxidoreductase and adipogenesis-related genes.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제55권10호
• /
• pp.461-466
• /
• 2006

In the present work, we investigated the photodissolution and photodiffusion effect on the interface of Ag/chalcogenide $As_{40}Ge_{10}Se_{15}S_{35}$ thin film by measuring the absorption coefficient, the optical density, the resistance change of Ag layer. It was found that the photodissolutioniphotodiffution ratio depends on the magnitude of photon energy absorbed in the chalcogenide thin film and the depth of photodiffution was proportional to the square root of the exposed time. Also, we have investigated the holographic grating formation with P-polarization states on chalcogenide $As_{40}Ge_{10}Se_{15}S_{35}$ thin film and $As_{40}Ge_{10}Se_{15}S_{35}/Ag$ double layer structure thin film. Holographic gratings have been formed using He-Ne laser (632.8 nm) which have a smaller energy than the optical energy gap, $E_g\;_{opt}$ of the film, i. e., an exposure of sub-bandgap light $(h{\upsilon} under P-polarization. As the results, we found that the diffraction efficiency on $As_{40}Ge_{10}Se_{15}S_{35}/Ag$ double layer structure thin film was more higher than that on single $As_{40}Ge_{10}Se_{15}S_{35}$ thin film. Also, we obtained that the maximum diffraction efficiency was 0.27 %, 1,000 sec on $As_{40}Ge_{10}Se_{15}S_{35}\;(1{\mu}m)/Ag$ (10 nm) double layer structure thin film by (P: P) polarized recording beam. It will offer lots of information for the photodoping mechanism and the analyses of chalcogenide thin films.

• Smart Structures and Systems
• /
• 제17권2호
• /
• pp.209-230
• /
• 2016

The Canton Tower is a high-rise slender structure with a height of 610 m. A structural health monitoring system has been instrumented on the structure, by which data is continuously monitored. This paper presents an investigation on the identified modal properties of the Canton Tower using ambient vibration data collected during a whole day (24 hours). A recently developed Fast Bayesian FFT method is utilized for operational modal analysis on the basis of the measured acceleration data. The approach views modal identification as an inference problem where probability is used as a measure for the relative plausibility of outcomes given a model of the structure and measured data. Focusing on the first several modes, the modal properties of this supertall slender structure are identified on non-overlapping time windows during the whole day under normal wind speed. With the identified modal parameters and the associated posterior uncertainty, the distribution of the modal parameters in the future is predicted and assessed. By defining the modal root-mean-square value in terms of the power spectral density of modal force identified, the identified natural frequencies and damping ratios versus the vibration amplitude are investigated with the associated posterior uncertainty considered. Meanwhile, the correlations between modal parameters and temperature, modal parameters and wind speed are studied. For comparison purpose, the frequency domain decomposition (FDD) method is also utilized to identify the modal parameters. The identified results obtained by the Bayesian method, the FDD method and a finite element model are compared and discussed.

• Wind and Structures
• /
• 제13권6호
• /
• pp.529-556
• /
• 2010

This paper investigates the correlation of wind characteristics monitored on a cable-stayed bridge. Total five anemoscopes are implemented into the bridge. Two out of 5 anemoscopes in inflow and two out of 5 anemoscopes in wake-flow along the longitudinal direction of the bridge are installed. Four anemoscopes are respectively distributed at two cross-sections. Another anemoscope is installed at the top of the tower. The correlation of mean wind speed and direction, power spectral density, the turbulent intensity and integral length of wind in flow at two cross-sections are investigated. In addition, considering the non-stationary characteristics of wind, the spatial correlation in time-frequency is analyzed using wavelet transform and different phenomenon from those obtained through FFT is observed. The time-frequency analysis further indicates that intermittence, coherence structures and self-similar structures are distinctly observed from fluctuant wind. The flow characteristics around the bridge deck at two positions are also investigated using the field measurement. The results indicate that the mean wind speed decrease when the flow passing through the deck, but the turbulence intensity become much larger and the turbulence integral lengths become much smaller compared with those of inflow. The relationship of RMS (root mean square) of wake-flow and the mean wind speed of inflow is approximately linear. The special structures of wake-flow in time-frequency domain are also analyzed using wavelet transform, which aids to reveal the forming process of wake-flow.

• 한국기계가공학회지
• /
• 제11권6호
• /
• pp.16-21
• /
• 2012

Magnesium alloy has been focussed as lightweight material owing to its high strength even though low density with aluminum alloy, titanium alloy and plastic material. Friction stir welding technique was performed by rotating and plunging a shouldered tool with a small diameter pin into the joint line between two butted plates and useful to join magnesium alloy. In this paper, the experiments of friction stir welding were done to investigate the joint characteristics of AZ31 magnesium alloy. For its evaluation, the orthogonal array method$(L_{27}(3^{13}))$ was applied with four factors of pin diameter, shoulder diameter, travel speed and rotation speed of tool and also three levels of each factor. Nine tools were worked through shoulder diameter of 9, 12, 15mm and pin root diameter of 3, 4, 5mm. In addition tensile tests were excuted for the assessment of mechanical properties for joint conditions. From the results, pin diameter, shoulder diameter, and rotating speed of tool influenced on the tensile strength meaningful, but welding speed did not influence on that by the variance analysis. Beside of that, optimum condition of tensile strength was estimated as following ; shoulder diameter:15mm, welding speed:200mm/min, rotating speed:200rpm.

• Journal of Ginseng Research
• /
• 제42권3호
• /
• pp.304-311
• /
• 2018

Background: Ginseng black spot disease resulting from Alternaria panax Whuetz is a common soil-borne disease, with an annual incidence rate higher than 20-30%. In this study, the bacterial strains with good antagonistic effect against A. panax are screened. Methods: A total of 285 bacterial strains isolated from ginseng rhizosphere soils were screened using the Kirby-Bauer disk diffusion method and the Oxford cup plate assay. We analyzed the antifungal spectrum of SZ-22 by confronting incubation. To evaluate the efficacy of biocontrol against ginseng black spot and for growth promotion by SZ-22, we performed pot experiments in a plastic greenhouse. Taxonomic position of SZ-22 was identified using morphology, physiological, and biochemical characteristics, 16S ribosomal DNA, and gyrB sequences. Results: SZ-22 (which was identified as Brevundimonas terrae) showed the strongest inhibition rate against A. panax, which showed 83.70% inhibition, and it also provided broad-spectrum antifungal effects. The inhibition efficacies of the SZ-22 bacterial suspension against ginseng black spot reached 82.47% inhibition, which is significantly higher than that of the 25% suspension concentrate azoxystrobin fungicide treatment (p < 0.05). Moreover, the SZ-22 bacterial suspension also caused ginseng plant growth promotion as well as root enhancement. Conclusion: Although the results of the outdoor pot-culture method were influenced by the pathogen inoculum density, the cropping history of the field site, and the weather conditions, B. terrae SZ-22 controlled ginseng black spot and promoted ginseng growth successfully. This study provides resource for the biocontrol of ginseng black spot.

• 한국자원식물학회지
• /
• 제28권1호
• /
• pp.93-100
• /
• 2015

유채 종자에서 기름을 착유한 후 부산물인 유채박을 토양에 처리하여 토양 내 선충을 친환경적으로 방제하기 위하여 실험한 결과를 보면, 유채박을 혼합한 토양이 OM, $Av.P_2O_5$, Ca, Mg, CEC 등의 수치가 증가하였으며, 유기물함량은 무처리 토양보다 3배가량 높게 나타났다. 또한 유채박의 glucosinolate 함량은 제주재래종 유채박이 $199.97{\mu}mol/g$로 선망 유채박의 함량보다 $76.62{\mu}mol/g$ 더 많았으며, 특히 progoitrin, gluconapin, glucobrassicanapin, 및 sinigrin 등의 함량이 높게 나타나기 때문에 유채박의 선충밀도 감소에 효과가 있으며 '선망' 유채박보다 제주재래종 유채박이 선충밀도를 더 줄여주었지만 유의적인 차이는 아니었다.