• 한국식품저장유통학회지
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• 제8권4호
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• pp.356-361
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• 2001

양파 간이저장시 노지야적에 의해 발생하는 부패를 감소시켜 망과의 안전저장을 위하여 조립식 간이하우스를 이용하여 통풍조건 및 통풍구 재료의 크기에 따른 저장성을 조사한 결과는 다음과 같다. 평균온도는 노지야적에 비해 강제통풍에서 0.3~3.6$^{\circ}C$높았고, 무통풍에 비해서는 1.4~8.2$^{\circ}C$가 낮았다. 그러나 처리간 유의차는 없었다. 상대습도는 통풍처리구에서 무통풍 및 노지야적에 비해 약간 높았다. 구중감소율은 노지야적에서는 2.5%, 무통풍에서는 2.9%, 자연통풍 2단에서는 3%, 강제통풍 2단에서는 4.3%였다. 8월 하순까지의 부패율은 자연통풍 2단 27.7%, 강제통풍 2단 25.4%,인데 비해 무통풍 34.6%, 노지야적 37.8%로 통풍처리구에서 부패가 적었다. 통붕구 재료의 크기가 클수록 평균기온은 조금 낮았고, 상대습도는 7월에 조금 높은 경향을 보이다가 8월 이후에는 차이가 거의 없었다. 통풍 파이프 표면의 풍속은 통풍구의 크기가 작을수록 강했으며, 부위별로는 중간부위가 양끝쪽보다 낮았다. 부패율은 75mm통풍구 17.9%, 100mm통풍구 15.3%, 125mm통풍구 14.1%로 통풍구 크기가 클수록 부패는 적었다.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.670-674
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• 2012

The photovoltaic performance of solid-state dye-sensitized solar cells employing hole transport material (HTM), 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene (spiro-MeOTAD), has been investigated in terms of HTM overlayer thickness. Two important parameters, soak time and spin-coating rate, are varied to control the HTM thickness. Decrease in the period of loading the spiro-MeOTAD solution on $TiO_2$ layer (soak time) leads to decrease in the HTM overlayer thickness, whereas decrease in spin-coating rate increases the HTM overlayer thickness. Photocurrent density and fill factor increase with decreasing the overlayer thickness, whereas open-circuit voltage remains almost unchanged. The improved photocurrent density is mainly ascribed to the enhanced charge transport rate, associated with the improved charge collection efficiency. Among the studied HTM overlayer thicknesses, ca. 230 nm-thick HTM overlayer demonstrates best efficiency of 4.5% at AM 1.5G one sun light intensity.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.247-247
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• 2012

Plasmon subwavelength nanostructures enable the structurally modulated color due to the resonance conditions for the specific wavelength range of light with the nanoscale hole arrays on a metal layer. While the unique properties offered from a single layer of metal may open up the potential applications of integrated devices to displays and sensors, fabrication requirements in nanoscale, typically on the order of or smaller than the wavelength of light in a corresponding medium can limit the cost-effective implementation of the plasmonic nanostructures. Simpler nanoscale replication technologies based on the soft lithography or roll-to-roll nanoimprinting can introduce economically feasible manufacturing process for these devices. Such replication requires an optimal design of a master template to produce a stamp that can be applied for a roll-to-roll nanoimprinting. In this paper, a master mold with subwavelength nanostructures is fabricated and optimized using focused ion beam for the applications to nanoimprinting process. Au thin film layer is deposited by sputtering on a glass that serves as a dielectric substrate. Focused ion beam milling (FIB, JEOL JIB-4601F) is used to fabricate surface plasmon subwavelength nanostructures made of periodic hole arrays. The light spectrum of the fabricated nanostructures is characterized by using UV-Vis-NIR spectrophotometer (Agilent, Cary 5000) and the surface morphology is measured by using atomic force microscope (AFM, Park System XE-100) and scanning electron microscope (SEM, JEOL JSM-7100F). Relationship between the parameters of the hole arrays and the corresponding spectral characteristics and their potential applications are also discussed.

• Structural Engineering and Mechanics
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• 제49권2호
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• pp.225-235
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• 2014

Cold expansion is an efficient way to improve the fatigue life of an open hole. In this paper, three finite element models have been established to bind the crack growth from an expanded hole and simulated. Expansion and its degree influence are studied using a numerical analysis. Stress intensity factors are determined and used to evaluate the fatigue life. Residual stress field is evaluated using a nonlinear analysis and superposed with the applied stresses field in order to estimate fatigue crack growth. Experimental tests are conducted under constant loading. Results of this investigation indicate expansion and its degree are beneficial to fatigue life and a good agreement was observed between FEM simulations and experimental results.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1434-1437
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• 2003

Sometimes open holes are required for the function and the weight reduction of structure and machinery. However, the serious stress concentration occurs because of the geometric discontinuity caused by the holes and cutting section. In this study, it is attempted to obtain the stress concentration coefficients of the inner surface of the hole boundary by changing the position and the shape of holes on the homogeneous isotropic plate. And the effects on the plate are investigated. The results show that the stress level becomes low and the distribution area widens the position of stress concentration changes as the ratio a/b increases and change to a circle. And as the ratio a/l decreases, the stress concentration reduces. As the plate with three holes. the stress $\sigma$$\_$x/ and $\tau$$\_$xy/ of hole 1,3 becomes high, especially $\sigma$$\_$x/ dominant and high.

• 한국자동차공학회논문집
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• 제3권6호
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• pp.123-133
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• 1995

An injection control valve(ICV) was designed to control the fuel flow between a common rail and an injector with two commercial solenoids. To improve the performance of ICV, the characteristic method was applied. With this method, the flow characteristics in the ICV and the injector were studied and the parameters which affect the injection characteristics were also studied. From this study, following results were obtained. The injection duration can be controlled and with modifications of the effective valve stroke of ICV, the injection quantity and duration can be reduced to desired amount. Also the injection quantity and pressure can be controlled by reducing the hole size of the injector without the variation of the injection duration. For some conditions, the desired injection characteristics can be obtained by the changes of the valve timing, the effective valve stroke, the open pressure of the injector and the hole size of the injector.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.93-96
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• 1996

We developed three dimensional Monte carlo ion implantation simulator which simulate distributions of impurities under the ion implantation on the tilted multi-layered layer. Our simulation reveals three dimensional shadow effect and sidewall scattering effect due to the geometrical shapes. For the evaluation of the developed three dimensional Monte carlo ion implantation simulator, calculations with 100,000 ions have been performed for the island and hole structures with a thin oxide of 100$\AA$ and nitride of 2000$\AA$. The simulation results showed that the distribution of ion decreases near the conner of the hole structure covered with a nitride layer and increases near the conner for the island structure open to oxide. Moreover, three dimensional distributions of ions were obtained with varying incident energy, tilt and rotation angle, mask depth and three-dimensional structure geometry.

• Advanced Composite Materials
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• 제16권2호
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• pp.115-134
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• 2007

This study proposes two new approaches for identifying damage patterns in a holed CFRP cross-ply laminate using an embedded fiber Bragg grating (FBG) sensor. It was experimentally confirmed that the reflection spectrum from the embedded FBG sensor was significantly deformed as the damage near the hole (i.e. splits, transverse cracks and delamination) extended. The damage patterns were predicted using forward analysis (a damage analysis and an optical analysis) with strain estimation and the proposed damage-identification method as well as the forward analysis only. Forward analysis with strain estimation provided the most accurate damage-pattern estimation and the highest computational efficiency. Furthermore, the proposed damage identification significantly reduced computation time with the equivalent accuracy compared to the conventional identification procedure, by using damage analysis as the initial estimation.

• 터널과지하공간
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• 제19권3호
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• pp.248-260
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• 2009

직접 개발 형식의 해외자원개발과 관련하여 단순 자본 투자에서 직접 개발로 변화하고 있다. 대규모 노천 석탄광산에서의 사면 안정성과 관련하여 지하수 유동 체계 분석과 사면 보강공으로서의 수평 배수공 타당성을 인도네시아 Pasir 탄광을 대상으로 검토하였다. 본 연구에서는 지하수 체계를 특징짓기 위해 지하수 수위 분석, 현장 투수 시험, 추적자 실험 등 다양한 현장 실험 및 계측을 수행하였다. 특히, 중부 지역의 상부에 위치한 SM강과의 연계성을 분석에 중점을 두었다. Guelph 투수계수를 활용하여 투수계수를 측정하였으며, 사암이 이암이나 탄층보다 투수성이 매우 높은 것으로 나타났다. 지하수 수위 분석 결과 사암층과 협재되어 많은 균열을 포함한 얇은 탄층이 주된 지하수 유동 경로 역할을 히는 것으로 나타났다. 추적자 시험 결과 SM강이 인근 지하수계에 미치는 영향은 강 바닥의 지층구조에 따라 다른 것으로 파악되었다. 수평 배수공의 효과를 파악하기 위한 2차원 지하수 유동 해석 결과는 폭이 좁은 탄층이 협재되어 있는 지층과 사암층이 주된 지하수 유동 경로이며, 충분한 심도로 수평 배수공 시공시 사면 안정화에 효과가 있는 것으로 파악되었다. 따라서 수평 배수공의 시공 위치와 시공 심도의 결정을 위해서는 지층 구조의 파악이 선행되어야 한다.

• 전자공학회논문지A
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• 제32A권8호
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• pp.47-55
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• 1995

Proximity-coupled open-end microstrip interconnections in bilevel planar structures are investigated through three-dimensional finite-difference time-domain(3D-FDTD) method. Three types of EMC (electromagnetically coupled) microstriplines are considered, collinear lines, transverse lines and modified EMC structure. From the analyzed results, it is found that these EMC interconnections have the coupling coefficient enough to interconnect lines in bilevel structures over a broad-band. The computed results of the modified EMC structure was compared with measurement from physical model and the computed results of via hole interconnection.