• 대한전자공학회논문지SD
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• 제49권6호
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• pp.25-34
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• 2012

본 논문에서는 near-field scanning (NFS) 시스템을 위한 새로운 보정 방법을 제시하였다. 제안된 교정 방법은 새로운 near-field probe (NFP)와 circular patch patterns (CPPs) and meander patterns (MPs) 같은 새로 고안된 패턴으로 구성되어 있다. 제안된 패턴들은 IEC61967-2과 6에 언급된 기존의 방법과 비교해 공간 해상도을 개선하고 NFP의 교정 절차를 단순화하기 위해 사용하였다. 또한 감쇄 특성에 대한 NFP의 길이 효과를 8mm와 30mm의 길이를 가지고 조사하였다. 이러한 특성을 위해 지름 (D)가 20, 40, 60, 그리고 100mm의 CPP를 만들었고 여러 가지 폭과 간격을 가지는 MP를 설계하고 제작하였다. 단순화된 교정 절차를 이용하여 공간 해상도와 측정 높이 사이의 역 관계를 발견하였다. 테스팅 결과는 측정 높이 $200{\mu}m$에서 $120{\mu}m$의 공간해상도를 복잡한 수정 알고리듬 없이 8GHz 아래에서 얻을 수 있음을 보였다. 제작 단가를 위해 모든 패턴과 NFP는 일반적인 고가의 LTCC 대신 저가의 PCB (FR-4)을 이용해 실현하였다. 이결과를 칩 수주 EMC 사용 가능성을 검증하기 Sub-micron scale 동작이 가능한 NFSS을 제작하였고, 제안된 NFP를 이용하여 사용 칩의 측정결과 $200{\mu}m$ 패턴의 형태를 정확하게 묘사가 가능한 수준의 해상도를 확보하여 칩 수준 EMC 검증에 사용 할 수 있음을 증명하였다.

• Journal of Korean Society for Atmospheric Environment
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• 제22권E2호
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• pp.78-88
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• 2006

In order to study the characteristics of cloud, a real-scale experiment for cloud generation was carried out using an extinct vertical mine (430 m height) located in the northeastern Honshu, Japan. The dry particles generated from the three-step concentrations of NaCl solutions were used for cloud generation. The number size distributions of initial dry particles and cloud droplets were monitored by Scanning Mobility Particle Sizer (SMPS) and Forward Scattering Spectrometer Probe (FSSP) at bottom and upper sites of pit, respectively. The polymeric water absorbent film (PWAF) method was employed to measure liquid water content ($W_L$) as a function of droplet size. Moreover the chemical properties of individual droplet replicas were determined by micro-PIXE. The CCN number concentration shows the lognormal form in dependence of the particle size, while the number size distributions of droplets are bimodal showing the peaks around $9{\mu}m$ and $20{\mu}m$ for every case. In comparison to background mineral particles, right shifting of size distribution line for NaCl particles was occurred. When NaCl solutions with three-step different concentrations were neulized, $W_L$ shows the strong droplet size dependence. It varied from $10.0mg\;m^{-3}$ up to $13.6mg\;m^{-3}$ with average $11.6mg\;m^{-3}$. A good relationship between $W_L$ and cloud droplet number concentration was obtained. Both chemical inhomogeneities (mixed components with mineral and C1) and homogeneities (only mineral components or C1) in individual droplet replicas were obviously observed from micro-PIXE elemental images.

• Asian-Australasian Journal of Animal Sciences
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• 제12권4호
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• pp.548-553
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• 1999

An experiment was conducted to study the effects of high dietary copper supplementation on the gastrointestinal tract morphology of broiler chickens. Eighty 3-week-old broiler chicks were divided randomly into eight groups of four dietary treatments and over three week were fed isoenergetic and isonitrogenous diets that contained 0, 100, 250, or 500 mg/kg of supplemental copper from cupric sulfate. The copper supplementation in the broiler diet up to 250 mg/kg did not significantly influence broilers' performance. A high dietary copper supplementation of 500 mg/kg did significantly depress growth and feed conversion in the broilers (p<0.05). Copper supplementation more than 250 mg/kg in the broiler diet significantly influenced the morphology of the GI tract, as shown by severe oral lesions and gizzard erosion. It also significantly depressed the villi height and significantly thickened the muscular layer in the duodenum (p<0.05). The severely damaged villi were observed by scanning electronic microscope from the duodenum samples of broilers fed a 500 mg/kg copper supplemented diet. The 500 mg/kg copper supplemented diet also significantly influenced the plasma constituents. Plasma glucose concentration was significantly depressed (p<0.05).

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.167-171
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• 2004

The electroless deposition of copper on the hydrogen-terminated Si(111) surface was investigated by means of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, scanning tunneling microscopy (STM), and energy-dispersive spectroscopy (EDS). The hydrogen-terminated Si(111) surface prepared was stable under air atmosphere for a day or more. It was found from ATR-FTIR that two bands centered at 2000 and 2260 $cm^{-1}$ appeared after the H-Si(111) surface was immersed in 40% $NH_4F$ solution containing 10 mM $Cu^{2+}$. On the other hand, STM image included the copper islands with a height of 5 nm and a diameter of 10-20 nm. The EDS data displayed the presence of copper, silicon and oxygen species. The results were rationalized in terms of the redox reaction of surface Si atoms and $Cu^{2+}$ ions in solutions, which are changed into $Si(OH)_x(F)_y$ containing $SiF_6^{2-}$ ions and neutral copper islands.

• ALGAE
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• 제23권1호
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• pp.83-90
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• 2008

Eelgrass beds are very productive and provide nursery functions for a variety of fish and shellfish species. Management for the conservation of eelgrass beds along the Korean coasts is critical, and requires comprehensive strategies such as vegetation mapping. We suggest a mapping method to spatial distribution and quantify of eelgrass beds using a digital echosounder. Echosounding data were collected from the northeast part of Kwangyang Bay, on the south of Korea, in March, 2007. A transducer was attached to a boat equipped with a DGPS. The boat completed a transect survey scanning whole eelgrass beds of 11.7 km2 with a speed of 1.5-2 m s-1 (3-4 knot). The acoustic reflectivity of eelgrass allowed for detection and explicit measurements of canopy cover and height. The results showed that eelgrass bed was distributed in depth from 1.19 to 3.6 m (below MSL) and total dry weight biomass of 4.1 ton with a vegetation area of 4.05 km2. This technique was found to be an effective way to undertake the patch size and biomass of eelgrass over large areas as nondestructive sampling.

• Applied Microscopy
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• 제42권3호
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• pp.124-128
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• 2012

Leaf surface structures were investigated in the Chinese juniper Juniperus chinensis by scanning electron microscopy. Adult scale leaves were collected from the tree, air-dried at room temperature, and sputter-coated with gold without further specimen preparation. Approximately fi ve stomata were locally distributed and arranged in clusters on the leaf surface. Stomata were ovoid and ca. 40 ${\mu}m$ long. The epicuticular wax structures of J. chinensis leaves were tubules and platelets. Numerous tubules were evident on the leaf regions where stomata were found. The tubules were cylindrical, straight, and ca. 1 ${\mu}m$ in length. They almost clothed the stomatal guard cells, and occluded the slit-shaped stomatal apertures. Moreover, the wax ridges were flat crystalloids that were connected to the surface by their narrow side. They did not have distinct edges, and their width/height ratio varied. In particular, the wax ridges could be discerned on the leaf regions where stomata were not present nearby. Since the wax ridges did not have distinct edges on their margin, they were identified as platelets. Instances were noted where platelets were oriented either parallel to each other or perpendicular to the cuticle surface. These results can be used in biomimetics to design the hierarchical structures for mimicking the plant innate properties such as hydrophobicity and self-cleaning effects of the leaf surface.

• 한국염색가공학회지
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• 제3권2호
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• pp.25-33
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• 1991

Poly(ethylene terephthalate)(PET) and nylon 6 films stretched uniaxially and biaxially were sputter etched in the presence of argon gas. The surface of the etched films was investigated using a scanning electron microscope(SEM). While cracks perpendicular to the stretched direction were observed in the uniaxil stretched films sputter etched for 30 min., many protrusions were formed in the biaxial stretched films at the height of 0.3-0.4 gm for PET and $0.1-0.2\mum$ for nylon 6. The tops of two or three protrusions merged etching time increased to 60 min. The contact angle to water of the sputter etched PET and nylon 6 films decreased steeply when etched for one to 3 min. In order to investigate chemical changes on the surface ESCA analysis was carried out. In both films sputter etched $C_{1s}$ intensity decreased and $O_{1s}$ intensity increased compared with the unetched ones.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2014년도 추계학술대회
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• pp.226-227
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• 2014

We demonstrate nanoscale local anodic oxidation (LAO) patterning on few layer graphene using atomic force microscope (AFM) at room temperature and normal atmosphere. We focus on the humidity dependency in nanoscale oxidation of graphene. The relationship between the oxidation size and the AFM setting values, such as set point, tip speed, and humidity are observed. By changing these values, proper parameters were found to produce features on demand size. This technique provides an easy way to form graphene oxide lithography without any chemical resists. We have obtained oxidation size down to 50-nm with 6-nm-height oxide barrier line with $0.1{\mu}m/s$ tip scanning speed and micrometer size symbols on a graphene flake. We attribute the bumps to local anodic oxidation on graphene surface and combination of oxygen ions into the graphene lattice.

• 대한치과기공학회지
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• 제36권3호
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• pp.179-184
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• 2014

Purpose: This study was performed to investigate the release behavior of bioactive materials as a BMP-2 embedding on the porous titanium implant. Methods: Porous Ti implant samples were fabricated by sintering of spherical Ti powders in a high vacuum furnace. Specimens diameter and height were 4mm and 10mm. Embedding materials were used to stamp ink. Sectional images, porosity and release behavior of porous Ti implants were evaluated by scanning electron microscope(SEM), mercury porosimeter and UV-Vis-NIR spectrophotometer. Results: Internal pore structure was formed fully open pore. Average pore size and porosity were $8.993{\mu}m$ and 8.918%. Embedding materials were released continually and slowly. Conclusion: Porous Ti implant was fabricated successfully by sintering method. Particles are necking strongly each other and others portions were vacancy. Therefore bioactive materials will be able to embedding to porous Ti implants. If the development of the fusion implant of the bioactive material will be able to have the chance to several patients.

• 한국식품영양과학회지
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• 제22권1호
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• pp.40-47
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• 1993

동부 앙금의 호화성질을 조사한 결과 물결합능력은 52$^{\circ}C$이후 급격히 증가하였고, 현탁액의 광투과도는 $65^{\circ}C$ 이후 직선적으로 증가하였으며 호화 온도는 63.4~76.$0^{\circ}C$이었다. 동부 앙금은 일단계의 팽윤과 용해도가 낮은 특징을 보였고, 호화에 필요한 수분 함량은 37%이었다. 아밀로그래프의 최고점도는 농도가 증가 할 수록 높아졌으나 일정한 농도에서 가열 온도에 따른 영향은 없었다. 각 가열 온도에서 20분 후의 점도와 3$0^{\circ}C$에서의 점도는 일정한 농도에서 가열 온도와 부의 상관관계 (p< 0.05)를, 냉각 점도는 20분 후의 점도와 농도에 관계없이 정의 상관관계 (p<0.05)를 보였다.