• 한국식품영양과학회지
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• 제45권8호
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• pp.1153-1161
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• 2016

흡습이 방지된 발효홍삼 농축액 알갱이를 제조하기 위해 홍삼의 지용성 추출액인 PSE(perfect soluble part in 70% ethanol)와 NSHW(not soluble part in hot water)를 70% 주정에 고형분 함량이 10%가 되도록 한 후 발효홍삼 농축액 알갱이를 유동하면서 이들을 발효홍삼 농축액 알갱이의 5%가 되도록 코팅하였다. PSE로 발효홍삼 농축액 알갱이를 코팅할 때 가장 중요한 인자는 feeding rate(FR)였고, NSHW는 FR${\times}$atomization air pressure(AP)임을 알 수 있었다. PSE와 NSHW를 이용하여 코팅된 발효홍삼 농축액 알갱이 제조 방법의 최적화 조건은 각각 FR 0.49 mL/min, AP 2.14 bar, product temperature(PT) $48.96^{\circ}C$에서 수율이 96.39%, FR 0.61 mL/min, AP 2.75 bar, PT $46.30^{\circ}C$에서 수율이 95.36%였다. 발효홍삼 농축액 알갱이의 용해성은 NSHW와 PSE로 코팅한 발효홍삼 농축액 알갱이가 코팅하지 않은 것보다 낮음을 알 수 있었다. 홍삼의 지용성 성분의 코팅이 발효홍삼 농축액 알갱이의 흐름성(편리성)에 크게 영향을 미치지 않았으나 흡습성은 방지되는 것을 알 수 있었으며 PSE보다 NSHW가 더 흡습방지에 효율적이었다. 총진세노사이드 함량은 홍삼의 지용성 성분으로 코팅하였을 때와 하지 않았을 때 통계적으로 차이가 없었지만, 지용성 성분을 코팅한 발효홍삼 농축액 알갱이의 진세노사이드 함량이 코팅하지 않은 발효홍삼 농축액 알갱이보다 진세노사이드 Rb1 함량은 높고 진세노사이드 Rg1의 함량은 낮은 값을 나타내었다. 관능특성 분석 결과 홍삼에서 분획된 지용성 추출물의 코팅은 손에 잘 묻지 않고 입안에서 잘 안 녹으며, 쓴맛이 오래가는 특징을 갖는 것을 알 수 있었다. 기호도 평가 결과 홍삼에서 분획된 지용성 추출물로 코팅한 발효홍삼 농축액 알갱이를 선호하지 않음을 알 수 있었다. 홍삼의 지용성 성분을 분획하여 제조한 PSE와 NSHW로 발효홍삼 농축액 알갱이를 코팅하였을 때 소비자들의 선호도는 낮았지만 흡습방지 효과는 높은 것을 알 수 있었다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.132-137
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• 2005

The burning characteristics of interacting spherical droplet in a turbulent flow are numerically investigated. The transient combustion of 3-dimensionally arranged droplets, both the fixed streamwise droplet distances of 3 radii and 10 radii and different turbulence intensities, is studied. The results obtained from the present numerical analysis show that droplet vaporization rate for heptane droplet is insensitive to turbulence intensity, and that the transient flame configuration and retardation of droplet surface temperature augmentation with streamwise droplet spacing substantially influence vaporization process of interacting droplets. Single flame mode in which individual flames are merged into single flame, with decreasing streamwise droplet spacing, becomes faster. Therefore, vaporization rate of the second droplet with decreasing streamwise droplet spacing decreases remarkably with flame movement.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.161-161
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• 2008

The oxide film of silicon wafer has been mainly polished by fumed silica, colloidal silica or ceria slurry. Because colloidal silica slurry is uniform and highly dispersed composed of spherical shape particles, by which the oxide film polished remains to be less scratched in finishing polishing process. Even though the uniformity and spherical shape is advantage for reducing the scratch, it may also be the factor to decrease the removal rate. We have studied the correlation of silica abrasive particles and CMP characteristics by varying pH, down force, and table rotation rate in polishing. It was found that the CMP polishing is dependent on the morphology, aggregation, and the surface property of the silica particles.

• 한국주조공학회지
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• 제23권3호
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• pp.130-136
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• 2003

Rheocasting of AZ91D magnesium alloys yielded the microstructure consisted of the spherical primary particles in the matrix which is different from conventional casting. Rheocast ingots were produced under various processing conditions using batch type rheocaster. Morphology of primary particles was changed from rosette-shape to spherical shape with increasing stirring rate$(V_s)$ and decreasing isothermal stirring temperature$(T_s)$. With increasing $V_s$, more effective shearing between the particles occurred rather than the agglomeration and clustering, so the primary particle size decreased. But with decreasing $T_s$, primary particle size increased mainly due to sintering and partially Ostwald ripening. The sphericity of primary particles increased with increasing $V_s$ and decreasing $T_s$ due to enhanced abrasion among the primary particles. The uniformity of primary particle size increased with increasing Vs and $T_s$.

• 한국세라믹학회지
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• 제45권11호
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• pp.725-733
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• 2008

In this study the preparation method of the spherical ADU droplets, intermediate compound of a HTGR nuclear fuel, was detailed-reviewed and then, the characteristics on an ageing and a washing steps among the wet process and the thermal treatment process on the died-ADU${\rightarrow}UO_3$ conversion with the high temperature furnaces were studied. The key parameters for spherical droplets forming are a precise control of feed rate and a suitable viscosity value selection of a broth solution. Also, a harmony of vibrating frequency and amplitude of a vibration dropping system are important factor. In our case, an uranium concentration is $0.5{\sim}0.7mol/l$, viscosity is $50{\sim}80$ centi-Poise, vibration frequency is about 100Hz. In thermal treatment for no crack spherical $UO_3$ particle, the heating rate in the calcination must be operated below $2^{\circ}C$/min, in air atmosphere.

• 한국세라믹학회지
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• 제51권4호
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• pp.243-247
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• 2014

Spherical NiO-YSZ particles were synthesized by ultrasonic spray pyrolysis (USP). The morphology of the synthesized particles can be modified by controlling parameters such as precursor pH, carrier-gas flow-rate, and temperature of the heating zone. The synthesized spherical NiO-YSZ particles have rough surface morphology at high carrier-gas flow-rates due to rapid gas exhaustion and insufficient particle ordering. The Ni-YSZ cermet anode synthesized by ultrasonic spray pyrolysis at a flow rate of l L/min, with precursor solution at pH4, showed a higher maximum power density of 256 $mW/cm^2$ compared to a conventionally mixed Ni-YSZ anode (185 $mW/cm^2$) at $800^{\circ}C$. While the area-specific resistance of conventionally mixed Ni-YSZ anodes increases gradually with operation time (indicating performance degradation), the Ni-YSZ anode synthesized by USP does not exhibit any performance degradation, even after 500 h.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.317-317
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• 2010

This paper reports syntheses of $TiO_2$ nanocubes and theirs application to DSSC. We synthesized $TiO_2$ nanocubes via solvothermal method using titanium isopropoxide (TTIP) and tetramethylammoiumhydroxide (TMAH). By adding longer alkyl chain ammonium hydroxide that slowed down the growth rate of the crystal, $TiO_2$ nanocubes were obtained with average particle size in the range of 40 nm to 70 nm. By TEM investigation, each particle was found to be single crystal of anatase having six-faces of (001) and {100} crystallographic planes truncated by {101} series of planes, which are clearly distinguishable from spherical nanoparticles. Among various application, utilizing nanocubes as photo-electrode in dye-sensitized solar cell, we investigated photo-electron conversion performances in comparison with spherical shaped $TiO_2$ nanoparticles by I-V characteristics and IPCE measurements, etc.. Photocurrent-transient analysis revealed that $TiO_2$ nanocubes have a higher transient electron transfer rate by more than 10 times compared with spherical particles of similar size. Fast electron transport along the cube edges having small curvature was suggested as a plausible origin of high diffusion coefficient of electron in nanocube $TiO_2$.

• 멤브레인
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• 제28권1호
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• pp.62-66
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• 2018

본 연구에서는 순수와 유사한 밀도의 세척형 구형 입자를 제작하고 순수 수조 내에서 산기량 및 입자 농도에 따른 입자의 유동 속도를 측정하였다. 세척형 구형 입자 1~3%를 MLSS 8,000 mg/L인 활성슬러지 용액에 주입하고 20 LMH 및 산기량 500 mL/min 조건에서 FR 및 SFCO 모드로 동시에 투과 실험하였다. 사용한 분리막은 유효 막면적이 $90cm^2$, 공칭 세공크기가 $0.4{\mu}m$인 평막이다. 입자 농도가 증가할수록 TMP가 감소하였으며 FR 모드, 입자 농도 2%일 때 가장 효과적인 것으로 확인되었다.

• 대한기계학회논문집B
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• 제22권8호
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• pp.1152-1163
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• 1998

In the present work, the image processing technique for measurement of drop sizes has been improved. Firstly, the local processing concept was adopted in addition to the global processing technique to take account of non-uniformity of the illumination intensity ; thereby, basically, the measurement error can be reduced. Also, the unfocussed image of drops can be eliminated more precisely since the elimination process is based on the local normalized contrast. Secondly the algorithms to process the partially detected or overlapped drop images and the non-spherical drop images were developed. Finally, the improved algorithm was tested by using an artificially prepared image-frame, where the partial or overlapped particles and the non-spherical particles are mixed with the normal spherical ones (with their true size-distributions known a priori). The results showed that both the recognition rate of the number of particles and the measurement accuracy were improved prominently.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.266-271
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• 2001

Spherical indentation technique was developed to evaluate the flow properties of metallic materials in carbon steel, stainless steel and alloys, etc. Through the spherical indentation test, differently degraded 1Cr-1Mo-0.25V steel's mechanical properties were observed and compared with conventional standard test data. The flow properties of 1Cr-1Mo-0.25V steels were estimated by analyzing the indentation load-depth curve. To characterize the flow property, we used material yield slope and constraint factor index rather than strain-hardening exponent because the variation of strain-hardening exponent was very little and the data showed irregularly. And the constraint factor's effect was small when the material yield slope was taken into account.