• 펄프종이기술
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• 제41권4호
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• pp.43-51
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• 2009

Paper mill sludges are discharged around 870,000 M/T annually. Only 30% of the paper mill sludge have been recycled and the rest has been disposed by land fill, incineration, ocean abandonment and other ways. Because of overall prohibition of sludge disposal by London Dumping Convention in 2012, a urgent counter measure for paper mill sludge must be provided. In this paper, some basic experiments were carried out to develop a tray cell pot using paper mill sludge for increasing the recycling potential of the wasted sludge. To establish the manufacturing parameters, the tray cell pots were made with three types of materials including virgin pulp, old news paper and corrugated board mixed in a blend tank of a molding machine. The bending force and moisture content of the produced tray cell pots was measured to confirm the application capability. The tray cell pot could be manufactured under the condition of over 20% of virgin pulp, 40% of old news paper added. However, the corrugated board could not be used because of the glutinous substance included. The produced tray cell pot absorbed water very easily and the bending force decreased rapidly. The waterproof material must be used to applicate the produced tray cell pot in plant growing fields.

• 한국포장학회지
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• 제22권1호
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• pp.1-6
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• 2016

빵을 발효하는 과정에서 반죽을 담는 용기를 기존에 사용하는 스테인레스 용기 대신 옹기를 이용하면 어떨까? 빵을 굽는 과정에서 철판이 아닌 옹기판을 사용하면 빵 맛에 영향을 미칠까? 하는 고민을 해보았고 이를 확인하기 위해 실험을 하였다. 결과는 발효실에서 옹기의 특성이 그대로 반죽에 긍정적인 영향을 주고 있었다. 옹기의 장점 중 하나인 보온성이 발효실 내부 온도와 더욱 가깝게 유지되며 반죽의 표면온도와 중심온도가 일치되는 시간이 스테인레스 용기를 사용하는 것보다는 짧은 시간에 이루어진다. 따라서 반죽의 전체온도를 낮은 편차에서 일정하게 유지됨으로써 발효시간을 단축시켜 줄 수 있는 장점을 가질 수 있다. 그리고 구운 후 제품의 부피와 표면 색상이 철판보다는 옹기판에서 좋은 결과를 보였으며 관능평가 역시도 기호도 면에서 우수한 평가를 받았다. 옹기를 사용함으로써 발효식품에 긍정적인 효과를 주듯이 빵을 만드는 과정에서도 옹기를 적절하게 활용한다면 더욱 더 좋은 품질을 생산할 수 있을 것으로 기대한다.

• 대한기계학회논문집B
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• 제34권8호
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• pp.775-782
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• 2010

본 연구는 대형 석탄 화력 발전소 탈황설비 내 흡수탑의 성능향상을 위하여 Tray 설치 가능성을 검토하기 위한 연구로 전산 유체역학(CFD) 기법을 이용하여 탈황설비 내 흡수탑의 내부유동을 전산해석 하였다. 흡수탑 내의 Gas와 Slurry의 거동에 대한 사실적 묘사를 위해 Euler-Lagrangian 기법을 이용한 전산해석을 수행하였다. 기존 흡수탑 내에 Tray를 설치함에 따라 탈황설비 내에서 Slurry의 체공시간 증가로 인한 펌프동력 절감과 압력강하 증가로 인한 Fan의 소요동력 증가에 대하여 중점적으로 비교 및 고찰하였다. 그 결과 Tray를 설치함에 따라 흡수탑 내에 Slurry의 체공시간과 배기가스의 압력강하가 증가되는 것을 확인할 수 있었다. 체공시간 증가로 인하여 절약된 동력이 압력강하에 의한 동력 소모량 증가보다 더 큰 것으로 확인되었다.

• 대한치과보철학회지
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• 제34권4호
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• pp.755-779
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• 1996

This study was designed to development of stock tray for Korean. The subjects for this study were 374 persons(male : 204, female : 170) with age $19{\sim}28$. The study models were made with irreversible hydrocolloid impression material and conventional stock tray, Individual trays were made on the study model and the master models were made after impression with polysulfide rubber impression material. Each of the master models measured 12 measuring points on the maxillary model and 13 measuring points on the mandibular model with digital sliding caliper. The values were analyzed statistically by SAS analysis. The measuring points were analysed and were consulted for the development of new stock tray for Korean. Maxillary models were divided into four groups acceding to the width between buccal alveolar ridges below the contact point of first molar and second molar. The size of new tray of the upper first group was 82mm (width), 60mm(length). That of the upper second group was 77mm (width), 59mm (length). That of the upper third group was 72mm (width), 58mm (length). And that of the upper fourth group was 67mm (width), 57mm (length). Mandibular models were devided into three group according to the width between lingual alveolar ridges below the second molar. The size of new tray on lower first group was 40mm (width), 55mm (length). That of the lower second group was 36mm (width), 55mm (length). And that of the third group was 32mm (width), 55mm (length). The author tested the fitness of newly designed stock tray in 52 subjects with normal occlusion and obtained good results that the problems of conventional stock tray were worked out.

• 대한치과보철학회지
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• 제39권3호
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• pp.282-296
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• 2001

The accuracy of master cast reproduction by a polyvinylsiloxane impression material using two visible-light curing resin and autopolymerizing polymethyl methacrylate resin custom tray material was investigated. Custom trays were fabricated from a master cast that had three index points marked on both inner and outer vestibules and then poured in yellow stone. The distance between the reproduced index points were measured to be ${\pm}0.001mm$ with a measuring microscope and the algebraic norms calculated for each tray material. No differences were found in the algebraic norms of inner and outer dimensions for upper tray impressions by ANOVA(p>0.05). However, T-test revealed that there were differences between upper and lower impressions and Tukey's hsd test revealed that in lower tray impressions, the Palatray in inner, the Lightplast in outer dimensions respectively were different from other materials. The index points reproduced on the casts compared with the master cast, were closer together for upper tray impressions. All four tray materials produced acceptable casts, 1. Algebraic norms of inner and outer dimensions of the test casts for upper trays were not statistically different irrespective of materials.(P>0.05) 2. T-test showed that there were differences between means with upper and lower trays especially in outer dimension.(P>0.05) 3. But, algebraic norms of inner and outer dimensions of the test casts for lower trays were statistically different between materials. 4. Palatray XL in inner, Lightplast-platten in outer dimensions respectively for lower trays were different from other materials, but, the nearest to the original model.

• The Journal of Advanced Prosthodontics
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• 제2권1호
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• pp.25-31
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• 2010

PURPOSE. This study compared the accuracy of an abutment-framework (A-F) taken with open tray impression technique combining cement-on crown abutments, a metal framework and resin cement to closed tray and resin-splinted open tray impression techniques for the 3-implant definitive casts. The effect of angulation on the accuracy of these 3 techniques was also evaluated. MATERIAL AND METHODS. Three definitive casts, each with 3 linearly positioned implant analogs at relative angulations 0, 30, and 40 degrees, were fabricated with passively fitted corresponding reference frameworks. Ten impressions were made and poured, using each of the 3 techniques on each of the 3 definitive casts. To record the vertical gap between reference frameworks and analogs in duplicate casts, a light microscope with image processing was used. Data were analyzed by two-way analysis of variance and the Tukey test. RESULTS. The open tray techniques showed significantly smaller vertical gaps compare to closed tray technique (P < .05). The closed tray and the resin-splinted open tray technique showed significantly different vertical gaps according to the angulation of implant (P < .05), but the A-F impression technique did not (P > .05). CONCLUSION. The accuracy of the A-F impression technique was superior to that of conventional techniques, and was not affected by the angulation of the implants.

• 한국식품위생안전성학회지
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• 제22권4호
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• pp.279-287
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• 2007

본 연구에서는 $1^{\circ}C$ 및 $5^{\circ}C$의 냉수와 $10^{\circ}C$의 지하수를 이용하여 세척한 후 PP film bag과 PETE tray로 포장하여 $4^{\circ}C$ 및 $10^{\circ}C$에서 9일간 저장하며 품질을 비교하였다. $10^{\circ}C$에서 저장하고 PP film bag에 보관한 세척하지 않은 치커리는 9일째 1.58%로 감모율이 가장 높았으나 $1^{\circ}C$ 냉수로 세척 처리한 후 PETE tray에 담아 $4^{\circ}C$에서 저장한 치커리는 0.14%로 감모율이 가장 낮게 나타났다. $1^{\circ}C$ 냉수로 세척처리한 후 PEIT tray에 담아 $4^{\circ}C$에서 저장한 경우 9일째 치커리의 호흡속도는 20.34 mg $CO_2/kg/hr$로 동일한 세척처리 후 PP film bag에 저장한 치커리의 호흡속도 26.12 mg $CO_2/kg/hr$보다 낮게 나타났다. 표면색의 변화에 있어서 시료별 개체차이가 심하여 L, a, b값의 유의적인 변화는 없었지만 저장 초기와 9일째를 비교하였을 경우 값이 전반적으로 다소 증가하였음을 알 수 있었고, 비타민 C는 $4^{\circ}C$의 저장고에서 저장한 경우가 $10^{\circ}C$에서 저장한 경우보다 비타민 C함량이 높게 유지되었다. 미생물에 있어서는 $1^{\circ}C$ 냉수로 세척 처리하고 PETE tray로 포장하여 $4^{\circ}C$에서 저장한 후 9일째의 치커리는 총균수 $2.59{\times}10^5CFU/g$, 대장균군수 $6.80{\times}10^2CFU/g$로 미생물수의 증식속도가 가장 느렸다. $1^{\circ}C$ 냉수로 세척하고 PETE tray로 포장하여 $4^{\circ}C$로 저장한 경우 치커리 고유의 초록색과 아삭한 조직감을 유지하고 있어 저온냉수 세척과 tray 포장이 세척 청경채의 선도 유지에 효과가 있는 것으로 나타났다.

• 대한치과보철학회지
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• 제39권5호
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• pp.492-501
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• 2001

The use of alginate impression materials today is prevalent because of its efficiency and simplicity in clinical settings. Unfortunately, the simplicity of the procedure tends to lull the dentist into a sense of well-being, and lead him into using careless or sloppy technique. Alginate impression materials are used to fabricate diagnostic and preliminary casts, and the final cast. Incorrect use of this material is known to affect the accuracy of the final prosthesis. The purpose of this study was to compare the effect of different mixing methods of alginate impression material and tray adhesive on the accuracy of the stone cast produced by each method. A total of 30 stone casts were produced by using 3 different types of mixing methods (10 stone cast for each mixing method, respectively). The first method utilized an automatic-mixing machine to mix alginate while the second method was carried out manually, strictly following manufacturer's instructions. The third method also involved manual mixing, but did not follow the manufacturer's instructions and was done in a random fashion. Also, 20 additional stone casts were produced by using alginate with or without tray adhesives were included in the study to evaluate effects of tray adhesives on the accuracy of alginate impression. 10 stone casts were produced by adding tray adhesives to the interior surface of the impression tray prior to taking the impression. The other 10 excluded this step. A total of 50 stone casts were analyzed by the three-dimensional measuring machine to measure and compare the dimensional changes of the impression material of each group. The results are as follows. 1. No significant difference was found between the automatic mixing group and the manually-mixing group(p>0.05). 2. For the group that followed manufacturer's instructions, less dimensional changes were record ed than the group that didn't in measuring distanced 4(p<0.05). 3. The group that used tray adhesives showed less dimensional changes(p<0.05). The findings revealed that mechanical methods of mixing alginate impression materials had little influence on dimensional changes. However, it is proven that following manufacturers instructions in alginate impression taking is an important step in acquiring accurate impressions and tray adhesives may play an important role in enhancing the results.

• 한국식품영양과학회지
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• 제37권2호
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• pp.231-238
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• 2008

본 연구에서는 1 및 $5^{\circ}C$의 냉수와 $13^{\circ}C$의 지하수를 이용하여 세척한 후 PP film bag과 PETE tray로 포장하여 4 및 $10^{\circ}C$에서 9일간 저장하며 품질을 비교하였다. $1^{\circ}C$ 냉각수로 세척하고 PETE tray로 포장한 경우 0.25%로 감모율이 가장 낮았고 이는 같은 냉수로 세척한 후 PP film bag로 포장한 0.39%보다 더 낮게 나타났다. 호흡속도는 $1^{\circ}C$ 냉수세척 처리하여 PETE tray로 포장하고 4 및 $10^{\circ}C$에서 저장한 9일 후 각각 45.71 및 53.15 mg $CO_2/kg/hr$로 PP film bag으로 포장한 경우보다 낮은 호흡률을 나타내었다. 표면색 변화에 있어서는 L 및 b값이 크게 변하지 않았고 비타민 C의 경우 초기 35 mg% 내외에서 저장 9일째에 $12{\sim}20\;mg%$로 감소하였으며, 1 및 $5^{\circ}C$의 세척수 온도별 유의적인 차이는 5 mg% 정도로 크지 않았다. 저장 9일째 $4^{\circ}C$에서 $1^{\circ}C$ 세척 처리하고 PETE tray로 포장하여 저장한 깻잎의 총균수는 $6.25{\times}10^4\;CFU/g$, 대장균군수는 $5.95{\times}10^2\;CFU/g$로 미생물수의 증식속도가 가장 느렸다. $1^{\circ}C$ 냉수로 세척하고 PETE tray로 포장하여 $4^{\circ}C$로 저장한 경우 깻잎 고유의 초록색과 향을 유지하고 있어 저온냉수 세척과 tray 포장이 세척 청경채의 선도 유지에 효과가 있는 것으로 나타났다.

• Current Research on Agriculture and Life Sciences
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• 제20권
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• pp.19-24
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• 2002

건전묘 생산을 위한 육묘 콘테이너의 선반 간격과 상자간의 배치간격을 달리하여 육묘하면서 이들이 모 생육에 미치는 영향을 조사하여 얻어진 결과를 요약하면 다음과 같다. 콘테이너의 선반 간격이 17 cm 에서 23 cm로 넓어짐에 따라 묘초장이 증가하였고 그 증가폭은 6월 10일 파종에서보다 5월10일 파종에서, 육묘일수가 길어질수록 큰 편이었다. 콘테이너의 선반간격뿐만 아니라 상자간의 배치간격도 모의 생장에 미치는 영향이 매우 컸으며 상자의 배치간격이 넓을수록 초장이 짧아지고 묘충실도는 증가하는 경향이었다. 육묘 콘테이너에 치상된 육묘상자의 위치에 따른 조도는 하단에서 상단으로 올라갈수록 높아졌고, 묘초장은 상단에서 하단으로 갈수록 큰 편이었다. 육묘콘테이너의 선반간격을 20 cm로 하고 육묘상자와 상자사이를 3 cm 정도 띄웠을 때 모의 황화현상은 크게 감소하였다.