• 환경생물
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• 제20권4호
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• pp.355-359
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• 2002

본 연구는 국화의 삽수 번식을 촉진할 수 있는 방사선의 적정선량 범위를 확인하고 저온저장과 방사선의 복합처리에 의한 영향을 알아보기 위해 수행하였다 삽수를 전개엽 3매, 길이 6cm로 균일하게 잘라 실험에 사용하였다. 네 주간의 저온저장 전과 후로 나누어 0∼70 Gy감마선을 조사하여 삽아하고 15일째와 20일째 발근 및 생육을 비교하였다. 그 결과 방사선 단일 처리에서는 30Gy 조사군이 높은 발근율과 빠른 근생장을 나타냈으며, 지하부 생육도 삽수 20일째 20, 30Gy 조사군에서 양호하게 나타났다. 저온저장 후 방사선을 조사한 경우 30 Gy 조사군에서 삽수의 생존율이 80%로 가장 높았다. 반면 방사선 조사후 저온저장을 시행한 경우 50Gy 조사군에서 지하부의 생육이 가장 높았으며 저온저장 후 방사선 조사를 한 실험군에 비해 지하부 생육이 우수하였다.

• 가정과삶의질연구
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• 제33권4호
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• pp.33-50
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• 2015

The purpose of this study was examining the effects of family sandplay therapy with structural family therapy in improving the family strengths of children with emotional and behavioral disorders. First, we looked for a way to combine family sandplay therapy with structural family therapy and formulated an approach that could maximize the strengths of each theory and complement each other's weaknesses. And then we applied family sandplay therapy together with structural family therapy and analyzed its effects on family strengths. The subjects of this study were 10 families of children with emotional and behavioral disorders, and they were divided into an experimental group with 5 families and a control group with the other 5. To the experimental group received 16 sessions of family sandplay therapy with structural family therapy. In order to prove the effectiveness of family sandplay therapy with structural family therapy on family strengths, a family relationship( husband-wife relationship, parent-child relationship, and sibling relationship) scale and a family function(family cohesion, family adaptability) scale were used. The main findings of this study are as follows. First, the family relationships of the families with emotional-behavioral disorder children were improved after the application of family sandplay therapy with structural family therapy. Second, the application of family sandplay therapy with structural family therapy improved the family function of families with emotional-behavioral disorder children. Third, in the course of family sandplay therapy with structural family therapy, family sand tray was changed in a pro-healing direction, and family structure was also transformed from a dysfunctional structure to a functional one. As previously stated, family sandplay therapy with structural family therapy for families of children with emotional and behavioral disorders enhanced family strengths through improving family relationships and restoring family functions.

• 대한치과보철학회지
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• 제34권4호
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• pp.850-868
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• 1996

The accuracy and dimensional stability of impression materials are one of the most important factors for successful prosthodontic treatment. The purpose of this study was to evaluate the accuracy of several dental elastomeric impression materials used widely and clinically : Impregum-$F^{(R)},\;Permlastic^{(R)},\;Silascon^{(R)},\;Perfect^{(R)},\;Xantopren^{(R)}$. There have been many studies to evaluate the accuracy of impression materials. But it has not been decided yet, which method was most suitable for the evaluation of the accuracy. In this study, two resin teeth, #15 & 25, were prepared with rounded shoulder margin and 90 degree cavosurface angle. For the polysulfide rubber and polyether, the custom tray was made at least 24 hours prior to impression taking. For the silicone rubber materials, putty/wash impression technique was applied in taking impressions. Marginal openings of the castings on the master dies and prepared resin teeth were measured under stereomicroscope. The results were statistically analyzed and compared between tested impression materials. The results were as follows ; 1. In the overall accuracy of impression materials, polyether was the most accurate one, followed by polysulfide, additional silicone and condensation silicone. 2. On the first model pouring, condensation silicone had the largest discrepancies and there was significant difference compared to the other impression materials. 3. Polysulfide had the least discrepancies in the first model pouring, but showed larger discrepancies in the immediate second pouring than the first pouring. 4. On the immediate second pouring, the discrepancy of polyether was shown to be the smallest, while the largest one was additional silicone. 5. Polyether and polysulfide rubber using custom impression trays showed superior accuracy to silicone rubber, putty/wash impression technique.

• Journal of Periodontal and Implant Science
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• 제28권1호
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• pp.177-185
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• 1998

치주염환자에서는 치아의 회전이나 순측경사등으로 인한 상악 정중부 이개 등의 심미적, 기능적 문제들이 자주 수반되어 후속 적인 교정치료를 요하는 경우가 많다. 이러한 경우 보조적인 교정치료로도 치료가 가능한데, 안정된 후방구치에서는 교정력을 가하지 않고 고정 원으로써 작용하게 하고 해당 치아만을 이동시켜야만 한다. 그러나 성인교정에서는 제한점들이 많기 때문에 비교정전문의에게는 섣불리 교정치료를 하기가 어렵다. 더구나 정확히 브라켓을 장착하는 것이 중요한데 간단한 문제는 아니다. Silverman등이 indirect bonding technique을 소개하면서 이런 문제점들을 해결하는데 도움을 주게 되었다. 그후 여러 사람 들에서 다양한 방법들이 소개되었지만 기본적인 원리는 구강 외에서 이상적인 위치에 브라켓을 위치시키고 tray를 이용해서 구강내 치아면에 재현하는 방법이다. 이런 방법을 이용함으로써 molar uprighting, forced eruption, 악교정술시 surgical arch wire 장착, 설측교정술 등에도 쉽게 적용할 수 있다. 이러한 관점에서, 비교정전문의들도 보다 쉽고, 정확하게 브라켓을 위치시킬 수 있는 indirect bonding technique를 이용한다면 보조적인 교정치료 뿐만 아니라 포괄적인 교정치료도 가능하리라 사료된다.

• 대한치과기공학회지
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• 제39권3호
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• pp.137-143
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• 2017

Purpose: The purpose of this study is to analyze the fitness of heat - pressed ceramic laminate veneers fabricated using the additive manufacturing. Methods: Impression was replicated by using light body silicone and heavy body silicone on the custom tray, and it was fabricated using Type IV Stone. The test specimens were prepared by using a dental scanner, a laminating veneer using a dental design program, and a specimen with a 3D printer. The control specimens were prepared by the lost wax technique and heat - pressed to fabricate the specimens. The data of the specimens were measured by the RMS value of the internal fitness a using a 3-dimensional measurement program. Results: The Stereolithography laminate veneer group was measured at $78.10(4.09){\mu}m$ and the LWV group was measured at $31.50(5.10){\mu}m$. There is a significant difference between the two groups (p<0.001) Conclusion : Evaluation of fitness laminate veneers was fabricated by additive manufacturing showed the difference statistically significantly and clinically acceptable result.

• 농업과학연구
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• 제40권3호
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• pp.197-202
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• 2013

This study was aimed to find the storage potential of low temperature adapted shiitake mushroom under freezing temperature ($-3^{\circ}C$). Fresh shiitake mushroom was harvested at late Feb. and cooled to target temperature, $-3^{\circ}C$ in the cooling room for 24 hr. Cooled mushroom were then placed in plastic boxes, wrapped with plastic film ($30{\mu}m$), and stored at $-3^{\circ}C$ for 2 months. Weight loss of mushroom was ranged from 2.1 to 3.2%. Dry weight per unit fresh weight, however, was slightly increased because of moisture loss. Firmness of fruit body increased from $0.95kg/cm^{-2}$ (before storage) to $1.13kg/cm^{-2}$ (after 2 month storage). About half amount of starch was lost during 2 month storage. The amount of total and reducing sugars remained relatively constant. After storage, freshness of mushroom was recovered by thawing treatment. When recovered mushroom were packaged with styrofoam tray and PVC wrapping, and exposed to ambient and $10^{\circ}C$, respectively, brown spot on the gill of fruit body was found and slight decay symptom was also found at ambient temperature only but not at $10^{\circ}C$. Results indicated that low temperature adapted shiitake mushroom has a storage potential under freezing temperature ($-3^{\circ}C$). Freezing storage technology of fresh shiitake mushroom will contribute the increase of storability up to 2 months.

• 한국식품과학회지
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• 제26권5호
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• pp.590-595
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• 1994

충진율을 다르게 하여 포장한 김치를 $10^{\circ}C$에서 저장하면서 포장내 기체조성, pH, 산도, 김치여액의 색도, 젖산균수 및 기호도의 변화를 측정하므로서 충진율이 김치의 품질에 미치는 영향을 조사하였다. 포장내 기체 조성은 충진율이 증가할수록 $O_{2}$의 감소와 $CO_{2}$의 증가 크기가 더 커졌다. pH와 산도는 그다지 충진율의 영향을 받지 않았으며, 색도의 경우에도 충진율에 관계없이 L, b 값은 지수적으로 감소하였고 a 값은 거의 일정하였다. 젖산균수와 관능검사 결과 역시 충진율에 따라 유의적인 차이가 나타나지 않았다. 이상의 결과로부터 김치의 포장시 충진율의 조절은 포장내 기체조성을 제외하고는 김치의 품질에 별다른 영향을 미치지 않는 것으로 판단되었다.

• 대기
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• 제26권1호
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• pp.73-84
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• 2016

A method to make ice spike using home refrigerator with ice tray was found. Many experiments have carried out with this method and many natural phenomena occurring on the formation of ice spike are found. A new concept of the Latter Freezing Water (LFW) was imported to explain the ice spike formation. At LFW position on water surface, the Sprout of Super cooled Water (SSW) grows by the Volume Expansion Effect (VEE) caused by the phase change of water in water. And air bubbles that are expelled from ice during freezing process, gather, rise, and detonate at the upper most part of SSW that make SSW freeze and grow upward with the water pipe in it. Together with VEE the capillarity in the water pipe makes the column grow more, that makes the ice spike. Many other findings were succeeded; 1) Ice spike process is completed before the whole water freezes. 2) If water is corrupted or shocked, even though it is very slight, ice spike is not generated. 3) Rain water contains the most LFW among all kind of waters used in experiments. 4) LFW is changed into normal water after passing the ice spike. 5) A new concept of the ice bullet is introduced. 6) The reason of frequent occurrences of the ice spike at Mt. Mai is investigated also.

• 대한소아치과학회지
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• 제25권3호
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• pp.539-544
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• 1998

저자는 열성형재료와 진공성형기를 이용하여 소아치과 임상에서 사용되는 수 종의 장치를 제작하였다. 전공성형기의 구입에 따른 경제적인 부담은 있으나, 기존의 제작법에 비해 제작이 간편하여 시간이 단축될 뿐 아니라 plate 의 두께가 균일하므로 finishing이 거의 필요하지 않으며 더욱 심미적인 장치를 제작할 수 있다. 또한 조직과 접촉하는 부위는 soft한 열성형재료를 사용하여 치아 이동에 유리할 뿐 아니라, 기존의 resin에 비해 불쾌한 맛이 적다는 장점이 있다. Monomer가 없어 조직에 자극이 적고 mutagenous potential이 없으므로 생체 적합성이 뛰어나 조직의 적응이 용이하다. 복잡하거나 특수한 기능 및 견고성이 필요한 악기능교정 장치 등에서는 그 사용이 제한된다는 한계점이 있으나, 소아치과 임상에서 사용되는 대부분의 장치를 쉽고 간편하게 제작할 수 있어 앞으로 임상에서 널리 이용될 수 있을 것으로 생각된다.

• Korean Chemical Engineering Research
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• 제45권4호
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• pp.351-355
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• 2007

$C_4$ 잔사유에 포함되어 있는 2-부텐을 부가가치가 더 높은 1-부텐으로 위치 이성화하는 공정의 개발이 필요하다. 본 연구에서는 2-부텐을 1-부텐으로 전환하기 위하여 상업용 Pd/alumina 촉매를 사용하여 수첨이성화반응 실험을 수행하였다. 상업용 Pd 촉매인 LD-265 촉매가 같은 반응조건에서 다른 상업용 촉매들보다 1-부텐 수율이 높았다. 1-부텐의 최적반응조건은 반응온도 $75^{\circ}C$, 반응압력 150 psig, 2-부텐의 유량 48 cc/h, $H_2$ 유량 48 cc/h이었으며, 이 조건하에서 1-부텐의 수율이 5.3%로 최대임을 알 수 있었다. 수첨이성화 반응기와 증류탑으로 구성된 공정의 모사를 수행하였다. 순도 99.0% 이상의 1-부텐을 얻기 위해서 단 효율이 78% 일 때 환류비가 120이고 171 단의 증류탑이 필요한 것으로 나타났다.