• 한국식품과학회지
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• 제16권4호
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• pp.429-436
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• 1984

스낵가공을 위한 보리의 압출성형특성을 조사하였고 가공조건이 제품의 품질에 미치는 영향을 분석하여 다음과 같은 결과를 얻었다. 압출성형을 위한 원료 보리의 적정 수분함량은 20%였으며 extrudate의 수분함량은 extrusion 온도가 증가할수록 die 크기가 감소할수록 낮았으며 Harper의 실험식에 의한 예측수분함량과 잘 일치하였다. Die swell은 0.98-2.18 정도의 값을 나타내었으며, $150^{\circ}C$ 이상에서 온도가 증가함에 따라 감소하였다. Extrudate의 밀도는 온도가 높을수록 die 크기가 작을수록 감소하였다. 또한 색택은 온도가 증가함에 따라 L, a, b 치가 큰 값을 나타내었다. 흡수율과 용해율은 $180^{\circ}C$에서 최대치를 나타내었으며 호화도는 온도가 증가함에 따라 증가하였다. Extrudate의 파괴응력, 영률, 최대응력은 온도가 높을수록 die 크기가 작을수록 감소하였으며 파괴점까지의 변형은 반대양상을 나타내었다. 또한 온도가 증가함에 따라 extrudate의 내부기공의 크기 및 비율이 증가하였다. 이상의 결과를 종합하여 볼때, 보리 스낵가공을 위한 최적 extrusion 조건은 스크류 회전속도 160 rpm에서 원료수분함량 20%, 온도 $180^{\circ}C$, die 크기 4.5 mm인 경우이었다.

• 한국식품영양과학회지
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• 제33권5호
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• pp.899-904
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• 2004

압출성형공법을 이용한 수삼의 전처리를 통한 추출수율의 향상과 최적조건에서 열수 추출한 인삼추출액의 첨가량을 달리하여 저온압출공정으로 제조한 구형과립의 입자분포, 마모율, 용적밀도, 진동밀도, 압축지수와 용출패턴을 결정하였다. 열수추출수율에서 수삼을 압출성형할 때 수분함량이 가장 유의적으로 영향을 미쳤다. 수분함량의 감소와 함께 스크류 회전속도가 증가할수록 압출성형 수삼의 추출수율이 크게 증가하였다. 추출수율이 최대가 되는 압출성형 공정변수는 수분함량 15%, 스크류 회전속도 250 rpm, 사출구 부위온도 13$0^{\circ}C$였다. 동일한 추출조건에서 15개 압출성형 수삼 시료의 평균 추출수율(43.5%)은 홍삼(38.3%)과 백삼(29.0%) 추출수율과 비교하여 크게 향상되었다. 저온압출공정으로 압출성형 수삼농축액(고형분함량 59.2%)의 농도를 5, 20, 30, 40, 50, 60%로 각각 증류수에 희석한 용액 200 mL과 200 g 미세결정 셀룰로오즈를 이용하여 과립화시킬 수 있는 압출성형 수삼추출액의 최대 농도는 60%였으며 추출액의 증가와 함께 입자수율의 증가, 마모율의 감소, 압출지수의 감소 등으로 입자의 물리적 특성은 구형과립을 젤라틴 캡슐에 포장하여 제품화할 수 있었다. 또한 압출성형 수삼 추출액을 포함한 구형과립으로부터 농축액 성분이 10분 이내에 쉽게 용출되므로 구형과립은 젤라틴 캡슐에 적합하다는 결론을 내릴 수가 있었다.

• Archives of Plastic Surgery
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• 제35권5호
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• pp.597-602
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• 2008

Purpose: Presently, silicone rubber is chosen most frequently for nasal augmentation. However, there is a possibility of extrusion with this material. Sometimes, noses are prone to be traumatized, and then silicone rubber has a possibility of deformity or deviation resulting in trauma. We experienced cases with complications and traumatic deformities after the augmentation rhinoplasty. Methods: A retrospective review was performed to determine the characteristics of the implanted nasal silicone prosthesis after trauma. The patients' data such as deviation of implant, shape of fracture, age and sex of the patient, time of treatment, operative methods were reviewed. From March 2001 to March 2008, this study was performed in 30 patients. The patients were 25 females and 5 males, from 24 to 60 years of age, with an average of 42. All patients had previous augmentation rhinoplasty with silicone implant. Results: All of the 30 patients were confirmed as deviation of silicone and nasal bone fractures in the facial bone CT scan. The most common cause of fracture was traffic accident. The classification of nasal trauma after augmentation was done by facial bone CT. Class I: Deviation of silicone without nasal bone fracture without extrusion(12 cases, 40%), Class II: Deviation of silicone without nasal bone fracture and with extrusion(4 cases, 13%), Class III: Deviation of silicone with nasal bone fracture and without extrusion(8 cases, 27%), Class IV: Deviation of silicone with nasal bone fracture and with extrusion(3 cases, 10%), Class V: Mild deviation of silicone with nasal bone fracture(3cases, 3%). Specially, the comminuted or trapezoid nasal fracture was confirmed in 11 cases(Class III, IV). Conclusion: The problems of silicone implant have generally been related to foreign body reactions, rigidity of the material, encapsulation, infections, and extrusion. We experienced 11 cases of comminuted or comminuted trapezoid shaped fracture below nasal implant. So, we think this phenomenon could be used in late problem of silicone implant.

• Journal of Ginseng Research
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• 제29권2호
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• pp.107-112
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• 2005

본 실험은 수분함량 $15\%$로 건조한 수삼을 사출구온도($100^{\circ}C$와 $120^{\circ}C$), 스크루 회전속도(200과 300 rpm)에서 압출성형처리하여 조사포닌,진세노사이드, 말톨, 환원당, 색도와 같은 홍삼성분의 변화를 분석하였다. 압출성형공정을 통해 조사포닌 함량이 증가하는 것으로 보아사포닌의 압출성형공정동안 생성되는 것을 알 수가 있었다. 홍삼에 존재하는 진세노사이드 $Rg_l$과 $Rg_2$는 사출구온도를 $100^{\circ}C$에서 $120^{\circ}C$로 증가함에 따라 0.227 mg/g에서 0.2835 mg/g$(Rg_l)$, 0.1164 mg/g에서 0.2230 mg/g$(Rg_2)$증가하였고, 스크루 회전속도를 300rpm에서 200rpm으로 감소시켰을 때 진세노사이드 $Rg_1$ 과 $Rg_2$는 증가하는 경향을 나타내었다. 또한 수삼이나 백삼에는 함유되지 않고 홍삼에만 함유된 특이성분으로 알려진 말톨을 압출성형 수삼에서 확인할 수가 있었다. 사출구의 온도가 $100^{\circ}C$에서 $120^{\circ}C$로 증가함에 따라 총당의 함량은 크게 변화가 없었지만 환원당은 온도가 증가할수록 감소하는 경향을 보였다. 결론적으로 사출구온도와 스크루 회전속도 이외의 압출성형 공정변수의 조절을 통해 압출성형공정을 홍삼제조 공정에 적용할 수 있는 가능성을 알 수가 있었다.

• 한국약용작물학회지
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• 제22권5호
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• pp.349-362
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• 2014

This study was designed to maximize extract yields of functional components in Angelica gigas Nakai by extrusion process. In addition, the optimizing condition of the extrusion process was established to increase the extraction of the functional components in A. gigas. The total polyphenol was increased by 40% compared to a control. And the optimizing condition was that the screw speed was 62.76 rpm, the amount of A. gigas powder was 34.79 kg/h, and the amount of water was 4.44 kg/h. The result of antioxidant activities of A. gigas extrusion, the inhibition of oxidization had the effect of 10.29 ~ 14.59% compared to a control. The content of decursin and decursinol angelate, which were index components, was 6.37%; it was increased by 16.64% compared to a control (5.31%) and showed a significantly difference (p < 0.05). And the optimizing condition was the screw speed 93.71 rpm, the amount of A. gigas powder was 28.67 kg/h, and the amount of water was 9.9 kg/h.

• Macromolecular Research
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• 제16권1호
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• pp.6-14
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• 2008

Polypropylene (PP)-layered silicate nanocomposites were developed using a new processing method involving a supercritical carbon dioxide ($scCO_2$)-assisted co-rotating twin-screw extrusion process. The nanocomposites were prepared through two step extrusion processes. In the first step, the PP/clay mixture was extruded with $CO_2$ injected into the barrel of the extruder and the resulting foamed extrudate was cooled and pelletized. In the second step, the foamed extrudate was extruded with venting to produce the final PP/clay nanocomposites without $CO_2$. In this study, organophilic-clay and polypropylene matrix were used. Maleic anhydride grafted polypropylene (PP-g-MA) was used as a compatibilizer. This study focused on the effect of $scCO_2$ on the dispersion characteristics of the clays into a PP matrix and the rheological properties of the layered silicate based PP nanocomposites. The dispersion properties of clays in the nanocomposites as well as the rheological properties of the nanocomposites were examined as a function of the PP-g-MA concentration. The degree of dispersion of the clays in the nanocomposites was analyzed by X-ray diffraction and transmission electron microscope. Various rheological properties of the nanocomposites were measured using a rotational rheometer. In the experimental results, the $scCO_2$ assisted continuous manufacturing extrusion system was used to successfully produce the organophilic-clay filled PP nanocomposites. It was found that $scCO_2$ had a measurable effect on the clay dispersion in the polymer matrix and the melt intercalation of a polymer into clay layers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1989년도 춘계학술대회 논문집
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• pp.77-80
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• 1989

The aim of the study is to develope the processing technique of PZT-Polymer piezoelectric composite materials for ultrasonic transducer application such as biomedical probe and hydrophone. Piezoelectric composite of PZT and polymer with 1-3 connectivity patterns have been fabricated by dicing-filling method and extrusion forming method. In this study processing forming method. In the study processing steps by extrusion forming method in the preperation of PZT/polymer piezoelectric composites are described. The PZT powder used in the study is commercial powder which is prepared by mixing PbO, TiO$_2$ and ZrO$_2$. The binder, water and plasticizer are mixed with the PZT powder to form a slip. It is necessary to adjust the viescosity of slip according on the PZT rod diameters to be extruded. The electromechanical properties of the piezoelectric composites are characterized in terms of the thickness resonance mode. The pulse response characteristics by the ultrasonic transducer analyzer and osciloscope are evaluated.

• 대한기계학회논문집A
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• 제24권8호
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• pp.2042-2049
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• 2000

This paper is concerned with the comparison of forging characteristics between forward and backward processes, through the three-dimensional finite element simulation, for the aluminum powder forging of engine pistons. Starting from the theoretical formulation of velocity and temperature fields in the sintered preform during the process, we examine the comparative distributions of relative density, effective stress and temperature as well as the variations of total forging load and total volume reduction. Through the comparative results, we find out that the forward method provides better forging characteristics than the backward method.

• 한국공작기계학회논문집
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• 제17권2호
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• pp.114-120
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• 2008

This study is to compare and analyze the material flow, deformation characteristics, and forming load of flange by means of similitude experimental method of model material using plasticine. In order to find optimal forming conditions, prototype experiments were designed to investigate forming characteristics of general-purpose flange under various working conditions. As a result of prototype experiments, billet thickness and gap-height ratio was found to be the most influential experimental parameter in flange forming. Forming loads from prototype experiments were compared to the results of finite element analysis after conducting estimation of forming loads of real material. Results of prototype experiments based on model material techniques are expected to be used as a basic data of die design f3r the development of products and process.

• 한국가스학회지
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• 제16권5호
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• pp.52-57
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• 2012

본 연구에서는 유한요소해석법을 사용하여 다접오링의 밀봉특성에 관련된 변형률, 응력, 접촉법선응력을 해석하였다. 밀봉특성에 관한 FEM 해석결과에 의하면, 다접오링에 작용하는 최대 변형률, 최대압축응력, 최대접촉 법선응력은 기존의 오링에 비해 약 1.7배나 더 높게 나타났다. 이것은 다접오링의 절단면에 U홈을 형성하였기 때문이고, 다접오링은 고압가스 용기, 밸브, 가스기기의 밀봉을 유지하는데 매우 유용할 것으로 판단된다. 그리고, 다접오링에서 가스압력을 높여도 압출파손 현상이 발생되지 않았는데, 이것은 U홈이 있기 때문인 것으로 판단된다. 따라서, 다접오링은 기존의 오링에 비해 밀봉수명을 길게 연장시킬 수 있다.