• 한국기계가공학회지
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• 제18권5호
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• pp.74-81
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• 2019

This study reports the CW $CO_2$ laser scribing of soda lime glass. In this study, scribing experiments are carried out at different laser powers, scan speeds, and focal positions to investigate the effect of the process parameters on the interaction characteristics between a laser beam and glass. In particular, the interaction characteristics are analyzed and described with the input laser energy per unit length. According to the experimental results, the damage threshold for the glass surface was found to exist between 0.072 and 0.08 J/mm. The input laser energy in this region induced partial melting of the surface and grain-shaped cracks. These cracks tended to increase as the input laser energy increased. At the laser input energy larger than 1 J/mm, a huge crack propagating along the scan direction was produced, and the volume below the scribed area was fully melted. The growth of this crack finally resulted in the complete cutting of the glass at the input laser energy above 8 J/mm. It was found that both the width and depth of the scribed line increased with increasing input laser energy. For the beam focusing at the rear surface, the width of the scribed line varied irregularly. This could be ascribed to the increased asymmetry of the beam intensity distribution when the laser beam was focused at the rear surface. Under this condition, a large burr was only produced on one side of the scribed line.

• 식품과학과 산업
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• 제50권2호
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• pp.12-26
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• 2017

Processing steps such as washing and cutting, involved in preparing fresh-cut produce causes tissue damage, leading to rapid quality deterioration. Major defects of fresh-cut produce are discoloration, softening, off-odor development, and microbial growth. Packaging of fresh-cut produce has been changed to reduce these quality problems. Flexible packaging film is widely used to pack fresh-cut produce. Vacuum packaging was the popular packaging method in the beginning of fresh-cut industry in Korea. Vacuum packaging creates high $CO_2$ and low $O_2$ levels to control browning of fresh-cut produce. However, these conditions induce some visual defects and off-odor development. Discoloration problem was also found when fresh-cut produce was packaged with conventional packaging film or plastic tray. Modified atmosphere (MA) packaging is effective for prolonging shelf-life of fresh-cut produce by decreasing $O_2$ and increasing $CO_2$ concentration in the package. Retail MA packaging using different oxygen transmission rate (OTR) film and micro-perforated film has started to be applied to fresh-cut produce in Korea. Proper MA package design that provides optimum range of $O_2$ and $CO_2$ partial pressures is one of the major challenges in the industry. An initial package flushing with $N_2$ or an low $O_2$/high $CO_2$ atmosphere is also used to more rapidly establish steady-state MA condition. Film OTR and $O_2$ flushing affects the fermentative volatile production, off-odor development, electrolyte leakage, discoloration, $CO_2$ injury, microbial population of fresh-cut produce. There is also a demand for convenient packaging to attract consumers. Rigid fresh-cut produce container for retail market has increased since the packaging provides excellent protection from physical damage during transport. Rigid tray used as actual serving vessel for the consumer is increasing in Korea. The tray with flexible lid to wrap or seal fresh-cut produce is more and more gaining popularity. Further practical technology to control quality change and microbial growth for each fresh-cut product has been studied since various fresh-cut items were required. The fresh-cut industry also focuses on searching for more convenient and environmentally friendly packaging.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제48권5호
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• pp.292-296
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• 2022

Objectives: During Le Fort I osteotomy, the separation of the pterygomaxillary junction (PMJ) is a difficult procedure for most surgeons because it is invisible. In this process, damage to the posterior structures constituting the sinus or those adjacent to it, including the maxillary sinus posterior wall and pterygoid plate, may occur. We would like to investigate the effects of this on the inside of the maxillary sinus after surgery and whether there are complications. Materials and Methods: One-hundred patients who underwent Le Fort I osteotomy from 2013 to 2020 using cone-beam computed tomography images were classified into two groups (clean-cut type and fractured type) according to the PMJ cutting pattern. In addition, the mucosal thickness in the maxillary sinus was divided into preoperative, postoperative three months, one year, and the change over the course of surgery was evaluated retrospectively. Results: Of the total 100 cases, the clean-cut type numbered 28 cases and the fractured type totaled 72 cases. Among the fracture types, part of the sinus wall and the pterygoid plate were broken in 69 cases, and the maxillary sinus posterior wall was detached in three cases. There was no statistically significant difference in sinus mucosal thickening between the clean-cut type and fractured type of the PMJ, three months and one year after surgery between the two groups. However, there was a significant difference in sinus mucosal thickness at postoperative one year in the case where a partial detachment of the maxillary sinus posterior wall occurred compared to not. Conclusion: Even if there is some damage to the structures behind the PMJ, it may not be reasonable to spend some time on the PMJ separation process considering the overall postoperative complications, if there is no significant difference inside the sinus, or increased probability of postoperative complications.

• Asian-Australasian Journal of Animal Sciences
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• 제22권3호
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• pp.396-403
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• 2009

Male broiler chicks were fed graded levels of organic zinc (zinc-methionine) supplementation to investigate the effects of partial or complete substitution of the organic zinc source for inorganic ones on the development of lymphoid organs and immunological responses. A total of 450 day-old male broilers were distributed into groups of 10 chicks and randomly assigned to nine experimental diets during a 42-day feeding trial. Dietary treatments consisted of two basal diets supplemented with 40 mg/kg added zinc as feed-grade Zn sulfate or Zn oxide in which, Zn was replaced with that provided from zinc-methionine (ZnMet) complex at the levels of 25, 50, 75 or 100%. Two randomly-selected birds from each pen replicate were bled and then slaughtered by cervical cutting on the final day of the trial to measure leukocyte subpopulations and relative weights of lymphoid organs. Among lymphoid organs, only thymus weight was affected (p<0.05) by dietary treatments. The sulfate-supplemented birds were heavier (p<0.01) in relative weight of thymus than oxide-supplemented birds. The 10 days of age-assessed cutaneous hypersensivity reaction was stronger in chicks fed ZnMet-containing diets. Dietary ZnMet supplementation caused (p<0.05) an increase in proportion of lymphocytes and consequently a decrease in heterophil to lymphocyte ratio. Diet fortification by zinc-methionine complex increased (p<0.01) Newcastle antibody titer at 19 days of age. Also, a similar response was observed in antibody titers at 6 and 12 d after infectious bronchitis vaccine administration. There was no significant effect of replacement of dietary zinc on antibody titer against infectious bursal disease virus (IBDV) at the 6th d post-vaccine inoculation; however, at d 12 after vaccination, ZnMet-fortified diets improved antibody titer against IBDV. Although dietary inclusion of ZnMet had no marked effect on primary antibody titer against sheep erythrocytes, effective responses were observed during secondary reaction from the viewpoint of both total antibody and immunoglobulin Y (IgY) titers. From the present findings, it can be concluded that dietary supplementation with organic zinc improves both cellular and humoral immune responses. It is necessary to replace 75% of supplemental inorganic zinc with organic ZnMet complex to achieve the optimum immunological responses in broiler chicks.

• 암석학회지
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• 제20권4호
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• pp.191-206
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• 2011

청주지역에 분포하는 화강암류 암석에 대한 SHRIMP 저어콘 U-Pb 연대측정, 전암 화학 및 전암 Sr-Nd 동위원소 특성을 살펴보고 이를 대보화강암체의 지구연대학적 및 지화학적 특성과 비교하였다. 청주 화강암체 내부의 섬록암에서 $174{\pm}2Ma$ ($t{\sigma}$), 이를 관입한 흑운모 화강암에서 $170{\pm}2Ma$ ($t{\sigma}$), 그리고 이 두 암 석을 모두 관입하는 산성암맥에서는 $170{\pm}5Ma$ ($t{\sigma}$)의 저어콘 연대가 산출하였다. 각 암석에서 측정한 절대연령은 노두에서 측정한 상대연령과 일치하며, 한반도 중부에 분포하는 대보화강암체에 대한 연대측정결과 (170-175 Ma)와도 부합된다. 청주 화강암체의 주원소 및 미량원소 분석 결과는 한반도 중부에 분포하는 대보화강암류 및 화강섬록암의 분석결과와 잘 일치하며, 섭입대와 관련한 I-type 화강암의 특성을 나타낸다. 하지만, Sr과 Nd 동위원소 조성은 청주 화강암체가 부화된 하부지각물질의 부분용융 산물이거나 지각 물질의 혼염 가능성을 지시한다. 더불어 저어콘의 상속핵 및 포획결정에서 산출되는 2.1, 1.8, 0.8 및 0.4 Ga의 다양한 저어콘 상속핵 연대는 연구지역 주변의 경기육괴와 옥천변성대의 암석들이 동화작용에 의해 혼염 되었을 것으로 판단된다.

• 한국의상디자인학회지
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• 제7권3호
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• pp.181-188
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• 2005

This study attempted to investigate the plastic characteristics of cyber punk fashion with a focus on fashion in the cyber punk movies in order to inquire into how the influence of the cyber punk taking the lead in the spiritual culture and way of life of the humankind in the 21th century would be expressed in fashion. For this purpose, it sought to analyze the beauty of new fashion creating the cyber environment and identify its contemporary meaning. An attempt was made to investigate the image of cyber punk fashion with a focus on fashion expressed in the cyber punk movies. As a result, the following findings were obtained: First, the image of cyber punk fashion expressed in the cyber punk movies was simplicity, which was to express the modest silhouette and details exclusive of decoration. In addition to clean and smooth gloss, it contained the modest image of resistance', not 'revolt' by borrowing the partial motive and image from existing punk fashion. The change of cyber punk fashion into the characteristic of concise, smooth external appearance brought about the restraint of its image and symbolism as well as its plastic characteristic. Second, it was characterized by the Eroticism nature of emphasizing the body line while expressing the future and modest image or exposing the body. Cyber punk fashion expressed the avant-garde image by using materials that gave a mysterious and future feelings, as well as unsymmetrical silhouette, the slit of body-conscious line, coarse cutting, the method of do-constructing and reconstructing the silhouette, the method of applying diverse underwears such as corset, brassiere and the like. Third, cyber punk fashion was marked by the nature of mined sex. It had the masculine image by using the black color containing the image of masculinity and resistance in female clothing and expressing the suit, coat and military looks giving an masculine impression. And it expressed the image of mixed sexes with the masculine image in male clothing by borrowing feminine images such as body-conscious line, widely cut neckline, floral decoration, leggings and the like. Fourth, cyber punk fashion was marked by naturalness. It was expressed as clothing made from silhouette, knit, cotton and the like in the atmosphere expressing love, comfortableness and truth. This contained the image of naturalness, a return to the primitive, that human being wanted to return to their original figure in the future element. The cyber punk movie may contain a dismal, gloomy future image on the whole, which can be overcome, and shows the possibility that it may grow into the alternative culture, not the revolting culture. The movie of 'The Fifth Element' demonstrates the meaning and role that shows the bright future image. It is thought that designers should make efforts for cyber punk fashion to perform its role in changing the gloomy future image into the bright image of society

• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.100-115
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• 1999

The purpose of this study was to investigate the distribution of calcitonin gene-related peptide containing nerve fibers in rat pulp after dentinl injury by means of immunohistochemistry and confocal laser scanning microscope. The Spague-Dawley rats weighing about 250-300gm were used. The animals were devided into normal control and experimental groups. Experimental animals were sacrified 1, 2, 4, 7, 10, 21days after dentinal injury (dentin cutting, and then acid etching with 35% phosphoric acid) on the maxillary molar teeth. The maxillary teeth and alveolar bone were removed and immersed in the 4% paraformaldehyde in 0.1M phosphate buffer (pH 7.4), then were decalcified with 15% formic acid for 10 days. Serial frozen $50{\mu}m$ thick sections were cut on a cryostat. The rabbit CGRP antibody was used as a primary antibody with a dilution of 1:2000 in 0.01M PB. The sections were incubated for 48 hours at $4^{\circ}C$, and placed into biotinylated antirabbit Ig G as a secondary anti body with dilution of 1:200 in 0.01M PB and incubated in ABC(avidin-biotin complex). The peroxidase reaction was visualized by incubating the sections in 0.05% 3,3 diaminobenzidine tetrahydrochloride containing 0.02% $H_2O_2$. For the confocal laser scanning microscopic examination, Primary antibody reaction was same as immunoperoxidase stainning, but fluorescein isothiocyanate(FITC)-conjugate antirabbit IgG as a secondary antibody was used. The confocal laser scanning microscope was used for the examination. A series of images of optical sections was collected with a 20x objective at $3{\mu}m$ intervals throughout the depth of specimen. FITC fluerescence was registrated through a 488nm and 568nm excitation filter, and images were saved on optical disk. The stereoscopic images and three dimentionnal images were reconstructed by computer software, and then were analyzed. The results were as follows : 1. In normal control group, CGRP containing nerve fibers were coursed through the root with very little branching, and then formed a dense network of terminals in coronal pulp. 2. A slight increase in CGRP containing nerve fibers at 1 and 2day postinjury was noted subjacent to the injury site. In the 4day group, there were an extensive increase in the number of reactive fibers, followed by a partial return toward normal levels at 7~10 day postinjury, and return by 21days. 3. The sprouting of the CGRP containing nerve fibers was evident within 2day after dentinal injury, and by 4days there was a maximal increased, but was decreased at 7days and returned to normal 10~21 day postinjury. 4. In confocal laser scanning microscopic exammination, the distinct distribution pattern and sprouting reaction of CGRP containing nerve fibers were observed in stereoscopic images and three dimentional images. These results suggest that CGRP containing nerve fiber can be important role in the response to dental injury and pain regulation.

• 원예과학기술지
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• 제33권4호
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• pp.501-510
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• 2015

본 연구는 수삽을 이용한 'Fuji' 사과나무의 발아 특성 관찰을 통해 자연상태에서의 내재휴면 개시 및 타파 시점을 찾고, 이에 필요한 저온요구도를 파악하고자 하였다. 또한, 동시에 휴면과 발아와의 관계를 좀 더 명확히 하고자 내부적인 눈의 발달 양상을 관찰하여 휴면과 저온 및 눈 발달간의 상호연관성을 파악하여 기후변화에 따른 변화들을 예상하고 대처하는데 필요한 기초 자료를 제공하고자 수행하였다. 'Fuji' 사과나무의 내재휴면 기간은 발아 소요 일수 및 발아율 조사를 통해 만개 후 165일부터 255일 사이 즉, 10월말부터 이듬해 1월 초까지 약 70일 정도 지속됨을 알 수 있었으며, 최초 발아까지 20일 이내, 최종 발아율 60% 이상을 기준으로 외재휴면에서 내재휴면으로, 다시 내재휴면에서 환경휴면으로 전환되는 시점을 찾을 수 있었다. 이렇게 도출된 내재휴면기 동안 요구되는 저온을 산출한 결과, 내재 휴면타파기인 만개 후 255일까지 축적된 저온은 CH 모델의 경우 666h, Utah 모델은 517CU으로 조사되었다. 휴면기 및 휴면타파기 동안 눈의 내부적인 변화를 관찰한 결과, 7월 중순경부터 꽃눈분화가 시작되었으며, 9월에는 중심화의 화원기의 구분이 가능하였다. 이후 꽃눈의 발달은 휴면 기간 동안에도 느리지만 지속적으로 진행되어 이듬해 2월에는 각 기관들의 발육 단계가 좀 더 진전되어 있음이 관찰되었다. 또한 'Fuji' 사과의 눈은 휴면 기간 동안 대부분 건전하게 생존해 있었지만 일부에서 화원기의 괴사현상이 발견되었고, 이는 저온에 의한 직접적인 영향이기보다는 얼음결정 형성으로 인해 일부 조직의 세포가 피해를 입고, 이로부터 괴사가 진행되고 있음을 확인하였다. 이러한 꽃눈은 과대지의 액아와 단과지의 정아에서 모두 형성되었으나, 전체 꽃눈 중 약 65%의 비율로 단과지의 정아에서 더 많은 꽃눈이 분화되고 있었으며, 이는 눈의 크기 및 눈이 위치한 가지의 직경과 직접적인 연관이 있었다.