• Journal of Acupuncture Research
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• v.36 no.1
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• pp.38-44
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• 2019

Background: The phrase "Nine Needles" refers to the 9 types of acupuncture needles describing their shapes, sizes, and uses in Huangdi's Internal Classic Ling-shu. The aim of this study was to present 3D illustrations of the "Nine Types of Needles" based on Huangdi's Internal classic Ling-shu, taking into consideration the conformation and application of the Nine Needles. Methods: Sketches of the "Nine Needles" were based on references to those needles cited in Huangdi's Internal Classic Ling-shu, the Great Compendium of Acupuncture and Moxibustion, and the Golden Mirror of Medicine. The computer programs Creo 3.0, Keyshot 5, Adobe Photoshop CS5, and Adobe Illustrator CS5 were used for 3D modelling and visualization. Results: Based on a review of Huangdi's Internal Classic Ling-shu, illustrations of the Spade needle, Round-Pointed needle, Pressure needle, Sharp-Edged needle, Sword-Shaped needle, Round-Sharp needle, Fine needle, Long needle, and Large needle, 3D models were created. The Spade needle had a sharp, large head, the Round-Pointed needle had an egg-shaped tip, and the Pressure needle had a blunt head like a grain of millet. The Sharp-Edged needle had a sharp blade with a triangular edge for bloodletting. The Sword-Shaped needle resembled a sword. The Round-Sharp needle resembled a horse's tail. The Fine needle and the Long needle had sharp points and thin bodies. The Large needle had a cylindrical shaft and rounded tip. Conclusion: This study demonstrated that 3D illustrations could be generated for the Nine Needles according to the descriptions and figures provided in the ancient literature.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.315-318
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• 2004

We developed a vapor induced crystallization (VIC) process for the first time to obtain high quality polycrystalline Si films by sublimating the mixture of $AlCl_3$ and $NiCl_2$. The VIC process enhanced the crystallization of amorphous silicon thin films. The LPCVD amorphous silicon thin films were completely crystallized after 5 hours at 480 $^{\circ}C$. It is known that needle-like grains with very small width grow in the Ni-metal induced lateral crystallization. In our new method, the width of grains is larger because the grain can also grow perpendicular to the needle growth direction. Also the interface between the merging grain boundaries was coherent. As the results, a polycrystalline film with superior microstructure has been obtained.

• Journal of the Korean Electrochemical Society
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• v.16 no.4
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• pp.191-197
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• 2013

The one of the cathode material, $Li(Ni_{0.5}Co_{0.2}Mn_{0.3})O_2$, was synthesized by the precursor, $Ni_{0.5}Co_{0.2}Mn_{0.3}(OH)_2$, from the co-precipitation method and the morphologies of the primary particle of precursors were flake and needle-shape by controlling the precipitation parameters. Identical powder properties, such as particle size, tap density, chemical composition, were obtained by same process of lithiation and heat-treatment. The relation between electrochemical performances of $Li(Ni_{0.5}Co_{0.2}Mn_{0.3})O_2$ and the primary particle morphology of precursors was analyzed by SEM, XRD and EELS. In the $Li(Ni_{0.5}Co_{0.2}Mn_{0.3})O_2$ cathode from the needle-shape precursor, the primary particle size was smaller than that from flake-shape precursor and high Li concentration at grain edge comparing grain center. The cycle and rate performances of the cathode from needle-shape precursor shows superior to those from flake-shape precursor, which might be attributed to low charge-transfer resistance by impedance measurement.

• Journal of the Korean Ceramic Society
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• v.25 no.3
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• pp.268-276
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• 1988

Ba or La-Substituted lead niobate $(Pb_{1-x}Ba_x)_{1-y}La_{2y/3}Nb_2O_6$(PBLN), powders having needle shape are prepared by flux method using KCl and the effect of Ba or La substitution on morphology of obtained powders is examined. From these needle shape powders, grain-oriented ceramics are made by doctor-blade method and two-stage hot-pressing technique. The dielectric, piezoelectric and optical properties of the ceramics are also investigaated. Heating condition and the amount of substituted Ba or La have remarkable effects have large anisotropy in both permittivity and coupling factor depending on the pressing direction.

• Journal of Power System Engineering
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• v.10 no.3
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• pp.51-57
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• 2006

The effect of grain size on corrosion resistance and high temperature oxidation behavior was studied in 22Cr-15Ni-5W super austenitic stainless steels for desulfurization equipment as a heat power station. In the high temperature oxidation test, oxidation rate was increased as the temperature increased from $600^{\circ}C\;to\;800^{\circ}C$. In vapor, oxidation rate was faster than that in air. Because the vapor was inhibited nucleation of $Cr_2O_3$ film. And the high temperature oxidation resistance at $600^{\circ}C{\sim}800^{\circ}C$ was excellent from all specimens and specimen of the smallest grain size was the most excellent. Because increasing of diffusion course through the grain-boundary was promoted nucleation and growth of $Cr_2O_3$ film. In the test temperature at $600^{\circ}C{\sim}800^{\circ}C$, Cr rich round particle oxide was formed in air, whereas Fe rich needle type oxide was developed in vapor.

• Journal of the Korean Society for Heat Treatment
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• v.24 no.6
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• pp.327-337
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• 2011

Effects of microstructural change, tensile properties and impact property according to the change of austenitizing temperature and tempering temperature of AISI 51B20 steel were examined. Regardless of austenite grain size, lath martensite with needle and packet shapes was found at tempering temperature of $300^{\circ}C{\sim}400^{\circ}C$. The needles of lath martensite changed to parallel packet at tempering temperature of $450^{\circ}C{\sim}600^{\circ}C$. As tempering temperature increased, tensile strength, yield strength and hardness decreased, while elongation, ratio of reduction area and Charpy impact energy increased. Grain size increased when quenching temperature was $930^{\circ}C$. Grain size had prominent effect on the mechanical properties of AISI 51B20 steel. Ratio of tensile strength/yield strength and yield strength autenitized at $880^{\circ}C$ followed by tempering at $350^{\circ}C{\sim}450^{\circ}C$ showed higher values than that of autenization at $930^{\circ}C$ due to fine grain size.

• Plant Disease and Agriculture
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• v.5 no.2
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• pp.111-114
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• 1999

A bacterial disease of rice plant that rotted the sheath to brown was found in rice plants at Tanbuk Uisong Kyungbuk in June 1999, When the bacterial isolates from the diseased rice plants were inoculated to health plant by the artificial needle prick method the same symptoms were examined. According to its characteristics and pathogenicity on the his plant the causal bacterium was identified as Burkholderia glumae which is known as the pathogen of bacterial grain rot of rice.

• Journal of the Korean Society for Heat Treatment
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• v.5 no.2
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• pp.85-94
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• 1992

Microstructural evolution of wrought Inconel 718 superalloy with different heat treatment conditions was studied. Heat treatment was performed via conventional(CHT), modified(MHT), Merrick(MeHT) and modified Merrick (MMeHT) methods. The size of ${\gamma}^{\prime}$ and ${\gamma}^{\prime\prime}$ precipitates which are principal strengthening phases in Inconel 718 superalloy increase in order of CHT, MHT, MeHT. For the case of MMeHT, a coexistence of fine ${\gamma}^{\prime\prime}$ precipitate and very coarse particles due to exess growth of ${\gamma}^{\prime\prime}$, which is called bimodal distribution, was observed. CHT gave the finest grain size. (Ti, Nb)C carbide and needle-like ${\delta}$ phase were formed together at grain boundaries for CHT, and were formed both inside and at boundaries of grains for MHT, MeHT and MMeHT. Morphology of partially serrated grain boundaries was developed in all heat treatment conditions except CHT.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.395-396
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• 2011

본 논문에서는 30% 내외의 평균반사율을 가지는 다결정 실리콘 태양전지의 입사광 손실을 최소화하여 광전변환효율 극대화를 구현하기 위해서 SF6/O2 혼합가스를 이용한 RIE 표면 texturing 공정을 수행하였다. 현재 다결정 실리콘 태양전지는 다양한 방향의 grain을 가지기 때문에 단결정 실리콘에 적용되는 습식 식각 방식이 다결정 실리콘 표면 texturing에 적절하지 않은 것으로 알려져 있다. 이를 개선하기 위해서 이방성 식각 특성을 가지는 다양한 texturing 방법이 시도되고 있다. 대표적으로 기계적인 방식의 V-grooving, 레이저 grooving, 플라즈마 건식식각을 이용한 texturing 및 산 용액을 이용한 texturing 등의 연구가 보고되고 있다. 그 중에서 플라즈마 건식식각 방식의 하나인 RIE를 이용한 표면 texturing 공정이 간단한 공정과 산업계 응용의 용이성 때문에 활발히 연구되어 왔다. 특히 Sandia group과 일본 Kyocera사의 연구 결과에서는 그 가능성을 입증하고 있다. 본 연구에서는 공정의 단순화와 안전한 공정을 위해서 SF6/O2 혼합 가스를 이용하여 마스크 패턴 공정없이 RIE texturing 공정을 수행하였으며, RIE-textured 다결정 실리콘에 대해서 태양전지를 제작하여 표면 texturing이 광전변환효율에 미치는 영향에 대해서 분석하였다. 그 결과 SF6/O2 혼합 가스를 이용한 RIE texturing은 다결정 실리콘 표면에 주로 needle 구조를 형성하는 것을 확인하였다. 각 texturing 조건별 반사율의 차이는 needle 구조의 조밀도와 관련되는 것을 알 수 있었으며, 동일 공정 parameter 상에서 식각 시간 1, 2, 3, 4, 5분 기준 시간에 따른 표면 구조 분석 결과 seed 가 형성되고 그에 따라서 needle 형태로 식각되는 과정을 관찰하였다. 반사율은 분당 약 4%씩 낮아져 5분 식각 후 14.45% 까지 낮아졌으며, 표면 구조에서 폭은 약 30 nm로 모두 일정하며, 길이가 약 20, 30, 50, 80, 100 nm으로 증가되었다. 이 결과로 보아 seed로부터 needle 구조가 심화되어가는 것을 알 수 있었다. 시간에 따른 RIE texturing 후 제작된 태양전지는 효율이 1분 식각 기준 15.92%에서 약 0.35% 씩 낮아져 5분 식각 후 14.4%로 낮아졌다. Voc 는 texturing 시간에 관계없이 일정하며 Isc가 점점 감소되는 것으로 확인되었다. EQE 결과도 이와 동일하게 RIE texturing 시간이 길어질수록 전체 파장 범위에서 일정하게 낮아지는 것이 관찰되었다. Electroluminescence(EL) 이미지 결과 texturing 시간이 길어진 태양전지일수록 점점 어두운 이미지가 나타나 5분 식각의 경우 가장 어두운 결과를 나타내었다. 이런 결과는 한 가지 이유보다는 복합적인 문제로 예상되는데 궁극적으로는 RIE 공정 후 표면에 쌓인 charged particle들이 trap 준위를 형성하여 효율 및 공정상에 영향을 미친 것으로 보이며, 특히 잔류 O기가 불균일한 산화막을 형성하는 것으로 예상된다. 또한 EL 분석 결과를 볼 때 RIE texturing 공정이 길어질수록 불안정한 pn-junction을 형성하는 것을 확인하였으며, emitter 층 형성 후 PSG (phosphorous silica glass) 공정에서 needle의 상부 구조가 무너지면서 면저항이 증가된 결과로 분석된다. PSG 제거 후 측정된 면저항의 경우 3분 texturing 샘플부터 면저항이 약 4${\Omega}/sq$ 정도 증가됨을 확인하였다.

• Journal of the Korean Ceramic Society
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• v.36 no.4
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• pp.432-443
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• 1999

The self-toughened Si3N4 ceramics where needle-like coarse ${\beta}$-Si3N4 grains were dispersed within fine-grain-ed matrix were prepared via hot-prssing at 1730$^{\circ}C$ for 2 h using 5 vol% ${\beta}$-Si3N4 whiskers as a seed. In this study the microstructures and mechanical properties of self-toughened Si3N4 ceramics were investigated. The flexural strength of self-toughened Si3N4 ceramics was increased from 600-800 MPa of the Si3N4 monolith to 830-1025 MPa. The KIC was also increased from 4.0-5.0MPa$.$m1/2 of the Si3N4 monolith to 5.8-6.5MPa$.$m1/2$.$The needle-like coarse Si3N4 grains in self-toughened ceramics were considered to induce various toughening mechanisms including the crack deflection pull-out and bridging and to contribute to KIC improvement. In ad-dition to toughening mechanisms the KIC improvement was considered to be partially indebted also to the orien-tation of large ${\beta}$-Si3N4 grains and to the promoting effect of ${\beta}$-Si3N4 whiskers on the ${\alpha}$ to ${\beta}$ transtion.