• Restorative Dentistry and Endodontics
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• 제21권2호
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• pp.470-488
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• 1996

The end products of the metabolism of the oral microorganism, organic acids, are an element that produces dental caries. Four organic acids in plaque fluid, lactic acid, acetic acid, succinic acid, propionic acid which take the important role in producing dental caries, were chosen to evaluate the effect of acid type and concentration. The subject, $100{\mu}m$ in thickness, were immersed in acid-buffer solution which has the different acid concentration of 10mM, 25mM, 50mM, 100mM and pH 4.3 and degree of saturation was $0.153{\pm}0.003$ kept in constant and were operated to produce artificial caries under different demineralization time (1, 2, 3 day) at x25. The results were obtained by observing under polarizing microscope at x25. 1. The subsurface lesion, specific finding of incipient enamel caries, showed positive birefringence. but surface zone and sound enamel showed negative birefringence. 2. The demineralization rate of enamel was increased as the acid concentration increased. 3. The subsurface lesion showed increasing depth in the order of lactic, acetic, propionic acid, succinic acid. 4. The concentration of organic acid in artificial caries system had an independent effect on demineralization rate in enamel under the constant pH and degree of saturation. The result of this study showed that not only pH and the acid strength but the concentration of organic acid had an independent effect on demineralization rate in early enamel caries. And through the further research on the factors influencing enamel demineralization, it will be necessary to develop an effective caries preventive therapy.

• 한국사회복지학
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• 제63권2호
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• pp.133-154
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• 2011

본 연구는 자녀와 동거하지 않는 65세 이상 노인을 대상으로 노년기 독립적인 삶의 기대감과 노인의 하향이전의 관계를 실증적으로 검토하여 분석하였다. 분석에 사용된 자료는 "2008년도 전국 노인생활실태 및 복지욕구조사"자료이며, 자료분석은 다중회귀분석을 이용하였다. 분석결과, 노인의 독립적인 삶의 기대감 정도는 노인의 하향이전 정도에 정적(+)인 영향을 주는 것으로 나타났으며, 구체적으로 경제적 신체적 독립적인 삶의 기대감은 노인의 경제적 서비스 하향이전에 정적(+)인 영향을 주는 것으로 나타난 반면, 심리적 독립적인 삶의 기대감은 노인의 서비스 하향이전에는 정적(+)인 영향을 주는 것으로 나타났지만 경제적 하향이전에는 영향을 주지 않는 것으로 나타났다.

• Journal of Advanced Marine Engineering and Technology
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• 제34권2호
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• pp.282-288
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• 2010

본 연구는 전자팽창밸브의 개도변화에 따른 가변속 수냉각기의 용량제어 특성에 관한 논문이다. 인버터에 의한 가변속 압축기를 사용한 냉각기를 최적으로 제어하기 위한 선행 연구이며 압축기 회전수별로 제어대상인 전자팽창밸브를 조절하여 증발기 출구의 과열도를 일정한 값으로 제어함으로써 최적의 냉각능력을 얻을 수 있는 과열도 값을 찾는 것을 목표로 하였다. 본 실험의 결과 압축기 회전속도가 일정할 때 팽창 밸브의 개도변화에 따라서 냉각능력이 최대가 되는 지점의 개도량을 실험을 통해서 파악할 수 있었다.

• 한국식생활문화학회지
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• 제11권1호
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• pp.53-59
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• 1996

This study was conducted to standardize the cooking methods of Omija-Pyuns and to investigate the effect of different starch densities (6% 7%, 8%, 9%) on the texture and taste of Omija-Pyuns. The results of these studies were as follows: 1) It was better for Omija to soak for 18 hours. The most favorite Mungbean starch density of 7% of Omija-Pyuns has the degree of lightness of 18.90, the degree of redness of 19.18, and the degree of yellowness of 3.98. 2) The Brix of syrup used for Omija-Pyuns was 49.4%. 3) As a result of the measurement of texture through Instron, if Mungbean starch density is increased, its hardness also increase. Each of the Omija-Pyuns (6%, 7%, 8%, 9%, in density) has showed its effection (p<0.05). 4) The result of the sensory evaluation showed that the Omija-Pyuns produced with Mungbean starch density of 7% was most preferred in appearance and overall taste, but it did not show the statistical effection (p<0.05) from the Omija-Pyuns produced with Mungbean starch density of 8%. The flavour was highest in Omija-Pyuns of 6%, and as the density was increased, the flavour decreased.

• Archives of Plastic Surgery
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• 제32권4호
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• pp.496-502
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• 2005

This study was performed to compare the effect of external ultrasound assisted PAL(power assisted liposuction) with that of PAL alone. We performed 17 cases of liposuction from January 2003 to June 2003. For comparing both systems, we treated the right side(study group) with external ultrasound assisted PAL and the left side(control group) with PAL alone. To evaluate the difference in results between two groups, we surveyed three objective and four subjective items. Objectives were categorized as "Reduction rate of postoperative swelling", "Efficiency of suction" and "Histologic finding of aspirated fat tissue". Subjectives were also filed as "Degree of postoperative bruising", "Cannula resistance that operator felt", "Degree of postoperative pain" and "Patient's satisfaction". We assessed by questionnaire three times at 1day, 7 days and 30 days after operation. There were statistically significant differences in two of the subjective items; "Degree of postoperative pain at postoperative 1 day" and "Cannula resistance that operator felt". This study concludes that external ultrasound PAL is more effective high mobility of fat tissue and low tension of surrounding tissue. External ultrasound PAL will be more useful in case of large volume liposuction and revision procedures.

• 대한가정학회지
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• 제18권1호
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• pp.41-46
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• 1980

In order to verify to what extent the rancidity of the soybean oil is occurred and how the various metal ions effect on the rancidity-as a result of applying heat to the soybean oil-the followings are obtained through experiments : 1. From analyzing the refractive index of soybean oil, The results are: the specific gravity-0.925 refractive index-1.475, saponification value-190, acetyl value-5.0, iodine value-120, peroxide value-5.0. 2. The degree of expediting rancidity take the following order : $Cu^{++}$/$Fe^{++}$/$Cr^{++}$/$Zn^{++}$/$Ni^{++}$/$Al^{+++}$. 3. The degree of expediting rancidity of $Cu^{++}$and $Fe^{++}$ is showed the abrubt increase of peroxide value in accordance with the increase of densidity. The most abrubt increase of peroxide show when the duration of heating reaches to the range between 20 minutes and 30 minutes. After heating for 60 minutes no definite variation is showed. 4. The degree of rancidity in heating the soybean oil added $Cu^{++}$, Fe and BHA shows the decrease of peroxide value by 2, 3 after adding $Cu^{++}$0.5 ppm. and heating for 30 minutes. As the result of measuring the value of peroxide after adding $Cu^{++}$ by 1.0 ppm and BHA by 0.01% and heating, peroxide shows the decrease by 7.8 when adding anti-oxidant. $Fe^{++}$ as well as $Cu^{++}$ shows that BHA prevents the metal ions from the expedition of rancidity.

• 한국약용작물학회지
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• 제23권4호
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• pp.271-276
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• 2015

This study was conducted to investigate the effect of shading degree and rooting media on the growth of Caragana sinica and Sedum middendorffianum after cutting. In C. sinica, the highest rooting rate was obtained in cuttings planted in horticultural soil (Sunshine Mix #1) and peat moss mixture (peat moss : perlite = 1 : 1, v/v) under one layer of 35% shading and in cuttings planted in kanumatsuchi soil mixture (kanumatsuchi soil : decomposition of granite = 1 : 1, v/v) under non-shading. Whereas, regardless of shading degree, most cuttings of S. middendorffianum rooted in both horticultural soil and peat moss mixture. Cuttings of C. sinica showed the highest root length, 10.4cm in kanumatsuchi soil mixture under one layer of 35% shading but the highest fresh and dry weight of roots in kanumatsuchi soil mixture under non-shading. In S. middendorffianum, the highest root length, fresh and dry weight of root were obtained in cuttings planted in horticultural soil under non-shading. With these results, we recommended that cuttings of C. sinica should be propagated in kanumatsuchi soil mixture under non-shading and cuttings of S. middendorffianum in horticultural soil under non-shading.

• 성인간호학회지
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• 제26권1호
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• pp.98-106
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• 2014

Purpose: The purpose of this study was to explore the effect of glove changing during surgery for colon cancer on reducing the degree of contamination of surgical gloves. Methods: The randomized posttest control group design was used. Total 72 surgeries of colon cancer in the K University Hospital in Seoul performed by the team of A-Surgeon and B-Scrub nurse were randomly assigned to one of the three groups. Glove changing with single-gloved state was implemented in the Experimental Group I and outer glove changing with double-gloved state was executed in the Experimental Group II. Single-gloved state was carried in the Control Group. Following the surgical procedure, specimens for bacterial culture were collected the from scrub nurse's gloves to compare the degree of contamination among the three groups. Data were analyzed with One-way ANOVA and the Scheff$\acute{e}$'s multiple comparison test. Results: The degrees of contamination of the Experimental Group I and II were significantly lower than that of the Control Group. There was no significant difference between Experimental Group I and II. Conclusion: Glove changing during surgery with either single or double-gloved state is effective in reducing the degree of contamination of surgical gloves, therefore these methods should be utilized in clinical practice.

• 펄프종이기술
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• 제38권2호
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• pp.9-15
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• 2006

Neutral sizing is required for linerboard to solve the troubles in strength and process caused by recycled raw materials. AKD sizing efficiency can be influenced by process condition like white water quality, fines retention and so on. Therefore, this study was aimed to evaluate sizing performance of general and fast cure type AKDs using process water obtained from linerboard mill. To evaluate effect of process water quality on AKD sizing, white water was diluted with tap water at the different dilution ratios and UKP slurry was sized using the prepared water. Also, effects of inorganic and organic ion material on sizing were examined. When white water was used for stock forming, UKP sheet showed very low sizing degree. Sizing degree of sheet was increased with increase of dilution ratio because water quality was improved. Especially anionic organic material had a greater influence on AKD sizing than inorganic material. When white water quality was deteriorated, fast cure type AKD showed superior sizing performance to general type AKD.

• 대한인간공학회지
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• 제29권2호
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• pp.183-188
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• 2010

The purpose of this study is to investigate the stationarity of the electromyographic signal in various flexion angles, loads, and window sizes, which influence the result of the mean power frequency (MPF) and median frequency (MNF) analysis. Six healthy subjects participated in the experiment. They were tested in the combination of 3-level flexion angles (0 degree, 22.5 degree, 45 degree) and 3-level loads (0Nm, 30Nm, 60Nm). Electromyographic data were collected for 20 seconds during isometric contraction. The stationarity of collected data were analyzed with four different window sizes including 250, 500, 1000 and 2000ms. Two test methods for stationarity such as Reverse Arrangements Test and Modified Reverse Arrangements Test were used. In order to show the effect of nonstationarity, the increasing/decreasing trend of MPF and MNF trend were discussed. In results, the stationarity of the electromyographic signal decreased as flexion angle increased and load decreased while window size decreased based on Reverse Arrangements Test. The highest stationarity was shown at 500 ms window in Modified Reverse Arrangements Test. The inclination of MNF and MPF indicated 3.6-6.3%, 3.8-5.1% discrepancy compared to the result from stationary data.