• 대한화학회지
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• 제54권6호
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• pp.749-754
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• 2010

본 연구에서는 IR과 CR의 블렌딩을 통하여 물성 개선 및 내구 성능 개선을 목적으로 IR/CR의 비율을 다양하게 블렌딩하여 제조한 고무시료의 가교 특성, 물성 변화, Morphology의 변화 및 화학적 특성을 조사하였다. 한편으로 블렌딩 된 고무에 다양한 조건으로 염소 표면처리를 하였을 때 고무시료의 Morphology를 관찰하고 마찰 시험을 통해 염소의 표면처리가 마찰계수에 미치는 영향을 조사하였다. 고무의 가교특성에서는 CR의 함량이 증가할수록 가교 속도가 감소하였으나 가교밀도는 일정하였고,경도, 모듈러스가 증가하였는데 이것은 가교특성의 변화와 밀접한 관계가 있으며, 가교 반응의 활성화에 의한 결정화 영향으로 기계적 강도가 증가하는 것으로 나타났다. 노화 후 물성 변화는 IR/CR Blend가 상호 기계적 물성의 단점을 보완하여 노화에 의한 물성 변화를 감소시키는 역할을 하는 것으로 나타났다. 염소 표면처리 한 시료의 노화 전, 후 상태물성의 변화는 감소하였다. 현미경 사진 관찰 결과 CR 함량 증가에 따라 표면 분산도가 증가함을 알 수 있었다. 염소 표면처리된 고무의 표면은 일정한 방향으로 균일하게 표면처리되었고 매끄러움과 광택이 증가하였다. 고무 표면의 개질 정도는 표면염소잔류량으로 확인할 수 있었으며, 마찰계수는 고무와 결합된 염소함량에 의존하는 것으로 나타났다. CR 함량이 10 - 40 phr까지는 표면처리 초기단계에서 마찰계수가 급격히 감소하였으나, 처리용액의 염소농도가 증가할수록 마찰계수의 감소는 둔화되었고, CR 함량이 50 phr에서는 처리용액의 염소농도 변화에 따라 마찰계수의 감소가 둔화되었다.

• 종양간호연구
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• 제5권2호
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• pp.136-145
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• 2005

Purpose: To investigate the degree and relationship of the quality of life(QOL) and family burden in hematopoietic stem cell transplantation recipients(HSCTr) at admission and discharge to isolation unit. Method: Data were obtained by interviewing from 60 HSCTr and 50 of their primary caregivers' and were analyzed by SAS program. Result: The degree of quality of life in pre and post HSCTr was significantly lower in the group who had physical discomfort compared with those who had no physical discomfort. The mean score of quality of life in pre HSCTr was significantly lower compared with in post HSCTr. Objective burden of family was higher than subjective one. Conclusion: QOL in HSCTr showed lower in the group of who had medical history, physical discomfort, no hope for cure and more than 5 weeks of length of stay. On the basis of these results, it is necessary to develop nursing intervention and to apply nursing care for improving their quality of life.

• Asian-Australasian Journal of Animal Sciences
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• 제5권4호
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• pp.733-736
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• 1992

Different parameters of subclinical mastitis were compared in 327 cattle and 493 buffaloes and the effect of immunopotentiating agents on subclinical mastitis in these animals was studied. Subclinical mastitis was detected in 8.2 percent buffalo and 24.0 percent cow quarter by modified whiteside test (MWT). In both the species there was decrease in lactose contents with increase in the degree of MWT reactivity i.e. $4.8{\pm}1.14$ to $2.31{\pm}0.82$ in cattle and $5.01{\pm}1.47$ to $2.36{\pm}1.02$ in buffaloes. While the chloride contents of the milk increased with increase in the MWT reactivity i.e. $0.19{\pm}0.4$ to $0.30{\pm}0.06$ in cattle and $0.20{\pm}0.04$ to $0.31{\pm}0.13$ in buffaloes. Micro-organisms belonging to Staphylococcus, Micrococcus, Bacillus, Streptococcus, Enterobacteria, Corynebacterium groups and yeasts were isolated from subclinical mastitis cases. Vitamin E and Levamisole cured 64.5 and 60.0 percent cases of subclinical mastitis in buffaloes but only 32.0 and 24.0 percent cases in cattle. Cure was not affected by the degree of MWT and the type of organisms involved.

• 응용화학
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• 제9권2호
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• pp.25-28
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• 2005

To evaluate the dental restorative application of polymer composites filled with hydroxyapatite (HAP) which is an inorganic component of human bone material, dental properties of the polymer composites were investigated. A visible light system was utilized to activate the acrylate resin matrix of the composites. Maximum loading percentage of HAP in composite was 65 wt% and the depth of cure was 6.0 mm which can be applicable for dental restoration. With increasing the HAP content, degree of conversion of polymer composites was slightly decreased, however, polymerization shrinkage value was not varied. Diametral tensile strength value was enhanced with an increase of HAP content, however, there was no strict trend between flexural strength and HAP concentration. Anyhow, polymer composites prepared herein have superior mechanical properties sufficient specifications applicable to dental materials.

• 산업기술연구
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• 제35권
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• pp.35-39
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• 2015

One of the purposes of the study was to investigate and compare the physical properties(depth of light cure, degree of conversion, water absorption) of 4 kinds of composit resins prepared in this lab; Bis-GMA based, Bis-EMA based, Bis-GMA/UDMA based, and Bis-EMA/UDMA based composit. Another aim was to compare the physical properties of the composit resins with those of the commercialized products(Charmfil flow(Denkist), Quadrant flow(CAVEX)) in market. All of the composit resins and the commercialized products showed almost same values of the physical properties. It was found that all of the composit resins prepared in this lab satisfied the physical properties specified in ISO 4049.

• Design & Manufacturing
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• 제16권2호
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• pp.60-65
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• 2022

In the pultrusion process for the CFRP (Carbon fiber reinforced plastic) rectangular pipe, the drawing device is eseential which can continuously produces products and draws the carbon fiber tow. In addition, since the degree of cure changes depending on the temperature and the temperature ditribution of the curing mold changes depending on the pultrusion speed, the temperature distribution of the curing mold under certain conditions must be studied before processing. In this study, in the pultrusion process using a closed impregnation method, which has several advantages compared to the general pultrusion process using a open bath impregnation method, the drawing force required to pull the carbon fiber tows and the temperature distribution of the curing mold was analyzed to design the drawing device and the curing mold efficiently.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 1999년도 춘계학술발표대회 논문집
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• pp.103-108
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• 1999

A synthesized model of pultrusion process considering thermally induced deformatiion was established. The model was composed of liquid resin flow model thermo-chemical analysis and linear elastic analysis. in order to verify the above-mentioned models several experiments were performed. A laboratory scale pultrusion line was established and glass/polyester composites were fabricated. the experimental results were compared with the calculated ones. The model successfully could estimate degree of cure pulling force and amount of process-induced deformation.

• 인터넷정보학회논문지
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• 제4권2호
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• pp.61-67
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• 2003

최근 섭취열량의 증가 및 운동부족으로 인한 비만이 사회적인 문제로 되었으며, 여러 가지 성인병의 위험인자로 알려져있다. 비만을 예방하고 치료하기 위해서는 우선적으로 비만평가가 이루어져야 하며, 이러한 평가에는 BMI, WHR, 허리둘레 등이 이용되고 있다. 본 논문에서는 제안되는 비만평가 시스템에서는 BMI와 허리둘레를 가지고 퍼지추론을 하여 비만을 평가하였다. 이를 위하여 BMI와 허리둘레에 대한 소속함수와 추론규칙을 결정하였으며, 추론 결과는 서술식 문장으로 나타냈다.

• Parasites, Hosts and Diseases
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• 제42권1호
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• pp.19-26
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• 2004

We investigated the induction of resistance to Clonorchis sinensis infection by prior infection in rat and hamster models. Animals were challenged with C. sinensis metacercariae, then treated with praziquantel and reinfected. Worm recovery rate in reinfected animals was used to estimate resistance to reinfection. The determined resistance rates to reinfection in rats and hamsters were 97.7% and 10.3%, respectively. In rats, cure from the primary infection of C. sinensis increased resistant to reinfection, and the greatert the worm burden and the longer the duration of primary infection, the higher was the resistance rate. For primary infection doses of 10, 40 and 100 metacercariae per rat, the resistance rates were 87.4%, 93.8% and 98.4%, respectively. The resistance rates in rats after 2 or 8-week primary infection were 78.7% and 95.3%, respectively. All worms recovered from reinfected rats were immature. When cured rats were administered with methylprednisolone, resistance to reinfection became impaired. These findings indicate that rats develop a high degree of resistance to reinfection by C. sinensis after cure. The growths and maturations of reinfected worms were also impaired.

• 대한한방내과학회지
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• 제29권3호
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• pp.621-628
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• 2008

Objectives : The aim of this study was to investigate changes of gastric vagal nerve activity and pyloric valve function after execution of combination treatments of both electroacupuncture at Zusanli(ST36) and manual acupuncture at other acupoints in patient with functional dyspepsia. Methods : Bowel sounds of 49 patients (18 male, 31 female) were recorded and their % of bowel sound (%BS) and ratio of dominant frequency (DF) were analyzed. Postprandial %BS was used to indicate the gastric vagal activity after eating. Ratio of postprandial/fasting dominant frequency was used to present the degree of pyloric valve function. According to values of %BS and DF ratio, each patient was classified into normal or abnormal (<6 %BS, hypoactivity: <1 DF ratio, dysfunction) group. For 2 weeks, patients received a treatment consisting of both electroacupuncture stimulation at Zusanli (ST36) and acupuncture at other meridian points. Variation of parameters shifting normal to abnormal or abnormal to normal was observed, and total cure rate was calculated. Results : Total cure rate of %BS was 16%, and that of DF was 37%. Patients who improved to normal value from abnormal or aggravated to abnormal level showed both significant difference in both vagal nerve hypoactivity and pyloric valve dysfunction, respectively. Conclusions : Analysis of bowel sound might be useful to evaluate both gastric vagal nerve activity and pyloric valve function. Combination effects of Zusanli (ST36) electroacupuncture and manual acupuncture of other acupoints showed a bidirectional effect in which their activity and function were in general improved. sometimes from aggravated to abnormal level.