• The Journal of the Korean dental association
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• v.24 no.3 s.202
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• pp.199-203
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• 1986

치과용 인상재는 구강내에서 치아나 주위조직을 정확히 인기하여야 하며 조작이 간편하고 유동성이 충분하며 경화시간이 적당하고 값도 저렴해야 한다. 또 구강내에서 제거할 때 영구변형이나 파절되지 않는 충분한 강도와 크기의 정확성도 있어야 하며 자극이나 독성이 없고 인체에 안정성이 있고 모형재와 친화성이 있으며 보관중에도 변질해서는 안된다. 그러나 인상재는 서로 상이한 특성이 있고 장단점이 각각 다르므로 모든 조건에 일치하는 인상재는 거의 없다. 따라서 여러 인상재중에서 가장 적합한 인상재를 선택하는 것이 중요한 과정이다. 즉 인상재의 특성과 응용을 알고 선택할땐 보다 정밀한 모형을 얻을 수 있다. 기록에 의하면 18~19세기경에 최초로 인상용 왁스를 사용한 이래 19세기 중엽에 인상용 석고, 1925년에 agar, 1930년 ZOE, 1945년 앨지네이트, 1957년 실리콘, 1967년 polyether 및 1975년 부가중합형 실리콘이 사용되었으며 인상재가 유연성과 탄성이 있는가 경고하며 비탄성인가 또는 온도변화와 화학반응으로 경화되는 가에 따라서 ZOE paste, 인상용 석고, 인상용 왁스, 인상용 콤파운드, 수성콜로이드(agar, 앨지네이트), polysulfide, 실리콘(축중합형, 부가중합형) 및 polyether 인상재등 10여종으로 분류된다.

• Food Science and Preservation
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• v.10 no.1
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• pp.1-5
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• 2003

This study was carried out to extend a marketing shelf-life of the Jeju greenhouse mandarin fruits. Total soluble solids were not showed any significant differences by the temperatures and pre-treatments during the marketing period. Acid content and firmness of the fruits were gradually decreased, which were better in cold than in room temperature treatment. The fruits washed in electrolyzed acid water(pH 2.4∼2.7) maintained freshness higher than those of control Internal CO$_2$concentration of those was 1.0 ％ more or less in the beginning marketing stage, but increased along the marketing period in mom temperature. Especially Internal CO$_2$concentration of wax-coated fruits rapidly increased more than any other, whereas it was a little decreased in cold treatment. After 10 days in room temperature, decay ratio of the fruits was below 4.0% in electrolyzed acid water washing, compared to 10.4% in control. After 30 days in cold temperature, decay ratio was only 3.7% in electrolyzed acid water washing compared to 4.4% of wax-coated treatment and 7.4% of control. The weight loss among the pre-treatments in room temperature had no significant differences and was higher than in cold one.

• Journal of the KSME
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• v.35 no.1
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• pp.63-70
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• 1995

연사기는 섬유공정 중에서도 기본적인 제직 준비공정으로서 연사기 시장은 개발도상국의 섬유 산업 진흥과 더불어 날로 확대되고 있다. 최근 섬유산업이 요구하는 연사기의 성능은 범용성\ulcorner 효율성 및 다양한 보조기능(실잇기, 패키지교체, 왁스나 요일의 첨가 등의 기능을 자동화하는 것 등)의 구비 등이다. 연사기의 생산성은 스핀들의 회전수가 높을수록 증대되므로 고속회전체 기 술의 개발이 시급하며, 다양한 기능의 자동화에 대한 연구\ulcorner개발이 뒷받침되어야 한다. 현재 우 리나라 연사기 기술수준은 다른 섬유기계에 비해 선진국 수준에 가깝게 접근해 있다. 따라서 연사기는 우리 섬유기계 산업계와 기계공학인 여러분의 적극적인 관심과 노력이 모아진다면 비 교적 단시간 안에 선진국과 견줄 수 있는 분야라고 생각된다.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.2
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• pp.29-38
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• 2010

The experimental study on paraffin wax/LDPE blended fuel for hybrid rocket was performed. Various combustion characteristics of blended fuel were compared with pure paraffin, HTPB, HDPE and SP-1a fuel in order to evaluate the performance of blended fuel. The regression rate of lab-scale and large-scale motor using pure paraffin fuel was increased by 10.2 and 9.8 factor when respectively compared to that of HDPE. The regression rate factor of blended fuel was 3.4 in which the regression rate of blended fuel was higher than that of HTPB and HDPE, but lower than that of pure paraffin, SP-1a fuel. The values of characteristic velocity and specific impulse of blended fuel was higher than those of pure paraffin, HTPB and HDPE, and almost the same as SP-1a fuel. As these results, it was confirmed that blended fuel can be an effective solid fuel for hybrid rocket.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.5
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• pp.70-76
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• 2016

Tensile and compressive strength tests were conducted to investigate the mechanical characteristics of aluminized paraffin wax fuel for hybrid gas generator applications. Mixtures of 0 wt%, 10 wt% and 30 wt% nano aluminum paraffin coupons as well as 5 wt%, 10 wt% and 15 wt% micro aluminum paraffin coupons were used. The average particle size of 100nm and of $8{\mu}m$ mixed each with microcrystalline paraffin wax(Sasol 0907) were chosen for the base specimens where the tensile strength test followed the ASTM-D638 specimen standard while the compressive strength test followed the ASTM D575-91. It was found that nano based specimens increased both the tensile and compressive strength enhancing the mechanical behavior of paraffin wax whereas the micro based specimens gave still less influential effect.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.396-399
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• 2002

면섬유는 천연적으로 지방, 왁스, 펙틴, 단백질 등 비섬유소 물질과 천연색소를 지니고 있는데다가, 제직 시 제직성 향상을 위해 가호를 하게 된다. 그러므로, 면섬유의 염색ㆍ가공을 효과적으로 하기 위해서 발호, 정련, 표백의 전처리 과정을 거치게 된다. 이 전처리 공정은 용수를 다량 소비하고 BOD/COD등의 폐수부하가 크므로 환경부하 감소의 차원에서 용수 재사용 기술개발과 환경친화적인 조제의 사용이 바람직하다. (중략)

• The Korean Journal of Rheology
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• v.2 no.1
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• pp.67-78
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• 1990

세라믹 분말의 사출성형성을 평가하기 위하여 다양한 혼합체 시스템에 대한 혼합도 와 유변학적 성질을 질화규소 미세분말의 부피비를 변화시키면서 조사하였다. 열가소성 결 합체 시스템은 폴리에틸린 폴리에틸렌 왁스 그리고 미소량의 첨가제를 혼합하여 사용하였 다. 혼합성능을 평가하기 위하여 비분산혼합에서는 총접촉면적비를 그리고 분산혼합에서는 총파괴표면적비를 혼합척도로서 사용하여 정성적으로 모형화하였다. 사용된 혼합기내의 유 동장을 해석하기 위하여 뉴우톤유체를 가정하여 유동해석을 수행하였다. 혼합물의 혼합도는 각각 5분 30분 동안 혼합된 시편을 주사전자현미경 사진에 의해 관찰하여 평가하였다. 또한 혼합물의 사출성형성 그리고 혼합질 점도 토우크 곡선 사이의 관계를 규명하기 위하여 전단 변형를 속도를 따른 점도를 모세관 점도계를 사용하여 측정하였으며 질화규소의 부피비가 60%일 때까지는 만족할 만한 성형성과 혼합질을 가짐을 알 수 있었다.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.1
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• pp.47-51
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• 2013

With the introduction of dental implants, restoration of missing teeth with conventional fixed or removable partial dentures is being replaced with implants. Especially, with young patients, not only longevity but also esthetic factors need to be considered. Implant restorations provide long-term success functionally but, esthetic complications such as, marginal exposure due to gingival recession, loss of the papilla and dark color of metal abutments may occur. Recently, zirconia restorations with CAD/CAM technology provide functional, biocompatible and esthetic restorations possible. All-ceramic restorations using the pressed ceramic technique show better fracture toughness values than those of the conventional porcelain veneering technique. Pressed ceramic technique creates the veneer design in wax and the lost wax technique is used to create the restoration. The final contour of the restoration may be controlled during wax-up. A 22-year old female patient was restored with dental implants and zirconia restorations using the pressed ceramic technique presenting short-term but optimistic prognosis.

• Transactions of the KSME C: Technology and Education
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• v.3 no.1
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• pp.45-53
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• 2015

The fact that gas hydrate and/or paraffin wax is frequently plugged in offshore pipeline has been become very significant for offshore piepline flow assurance. An active electrical heating along pipeline has adapted in resolving flow assurance problem like as gas hydrate and wax plugging. This study represents a novel internal-swirled heater which was designed and fabricated for more effective heating and thermal mixing through pipeline. The internal-swirled heater suggested in this study shows higher thermal mixing performances than the conventional external-traced heater.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.3
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• pp.255-262
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• 1996

This study was carried out to investigate the effects of soil fertilizers on wax content, contact angle, mineral nutrient content of Japanese red pine (Pinus densiflora Sieb, et Zucc.) leaves and soil acidity of Japanese red pine communities in Namsan and Kwangnung to see whether they can recover forest decline. Japenese red pine communities were treated with $Ca(OH)_2$, $Mg(OH)_2$, $Ca(OH)_2+Mg(OH)_2$+C.F.(compound fertilizer) in a randomized complete block design with 3 replication from November, 1990 through October, 1993. Wax content, contact angle value and mineral nutrient content of Japanese red pine leaves and soil pH of communities were measured and the results obtained are as follows: 1. Contact angle value and wax content of Japenese red pine leaves increased when the fertilizers were applied in soil. The order leaves grew, the smaller their contact angle values. 2. K and Ca contents of Japanese red pine leaves were higher in Namsan than in Kwangnung, whereas Mg content was higher in Kwangnung. K and Mg contents of the leaves increased with fertilization both in Namsan and Kwangnung. 3. Soil acidity of pH 4.2 ~ 4.3 was shown in Namsan and pH 4.6 ~ 4.9 in Kwangnung. No acidity changes were shown when the fertilizers were applied in soil. However with the lapse of the soil fertilizer application time, there was the indication that soil pH became higher in the fertilizer treatments than in the control.