• 제목/요약/키워드: depth of cure

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Physical properties of composite resins for dental restorative (치과 수복재용 복합레진의 물리적 특성에 대한 연구)

  • Kim, Ji Yeob;Lee, Kwang-Rae
    • Journal of Industrial Technology
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    • v.35
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    • pp.35-39
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    • 2015
  • One of the purposes of the study was to investigate and compare the physical properties(depth of light cure, degree of conversion, water absorption) of 4 kinds of composit resins prepared in this lab; Bis-GMA based, Bis-EMA based, Bis-GMA/UDMA based, and Bis-EMA/UDMA based composit. Another aim was to compare the physical properties of the composit resins with those of the commercialized products(Charmfil flow(Denkist), Quadrant flow(CAVEX)) in market. All of the composit resins and the commercialized products showed almost same values of the physical properties. It was found that all of the composit resins prepared in this lab satisfied the physical properties specified in ISO 4049.

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Mother's Experience of Caring Child with a Severe Atopic Dermatitis (중증 아토피 피부염 환아를 돌보는 어머니의 경험)

  • Chang, Eun-Young;Chung, Seung-Won;Lee, Ja-Hyung
    • Korean Parent-Child Health Journal
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    • v.9 no.1
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    • pp.17-32
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    • 2006
  • The purpose of this study was to understand mother's experience of caring child with a severe atopic dermatitis. Twelve participants were selected and collected on their caring difficulties using in-depth interview. Data were analyzed according to the method of Colaizzi. Significant statements were extracted from the data. From the significant statement, 18 clusters of themes and 7 categories were emerged. Eighteen cluster of themes formed 7 categories : Thinking of atopic dermatitis during 24 hour, Mom would cure you, You are atopic, I'm depressive, I need 12 or more bodies to take care of him/her, Great conversion of daily life, From a bitterness to a frailness, In peace with an atopic dermatitis. In this study, it was implicated that mothers were suffered from caring children with an atopic dermatitis and nurses need to have more interests in the maternal stress and their quality of life as well as provision of information.

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Study on the Roughness Improvement using Parameter of Rapid Prototyping (쾌속조형 파라미터를 이용한 표면형상정밀도 향상에 관한 연구)

  • Park, Gae-Duck;Kim, Tae-Ho;Jeon, Eon-Chan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.6 no.3
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    • pp.77-84
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    • 2007
  • As a life cycle of product bas shortend, Rapid prototypiug has come into the spotlight to shortened the time of producint a prototype. But It followed in laminated directivity and of the prototype production which is decided the interference which Beccuase of invisible rough surface, some inferences have occured during an assembly hour. Consequently, This study on rapid prototyping has parameter to determine surface roughness and surface form precision of total shape. In order to improve Surface form precision, it can control parameters which are Laminate Height, Layer Hatch Overcue, Fill Cure Depth. In addition, we found the parameter which have a deep effect on surface roughness among various parameters, and then, tried to reduce the interference that can be occurred by surface roughness during assembly.

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Ceramic Stereolithography: Additive Manufacturing for 3D Complex Ceramic Structures

  • Bae, Chang-Jun;Ramachandran, Arathi;Chung, Kyeongwoon;Park, Sujin
    • Journal of the Korean Ceramic Society
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    • v.54 no.6
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    • pp.470-477
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    • 2017
  • Ceramic processing to fabricate 3D complex ceramic structures is crucial for structural, energy, environmental, and biomedical applications. A unique process is ceramic stereolithography, which builds ceramic green objects from CAD files from many thin liquid layers of powder in monomer, which are solidified by polymerization with a UV laser, thereby "writing" the design for each slice. This approach directly writes layers in liquid ceramic suspension and allows one to fabricate ceramic parts and products having more accurate, complex geometries and smooth surfaces. In this paper, both UV curable materials and processes are presented. We focus on the basic material principles associated with free radical polymerization and rheological behavior, cure depth and broadening of cured lines, scattering at ceramic interface and their corresponding simulation. The immediate potentials for ceramic AM to change industry fabrication are also highlighted.

THE COMPARISON OF POLYMERIZATION OF COMPOSITE RESIN INFLUENCED BY CURING DEPTH AND SHADE (광중합 복합레진의 색상과 깊이에 따른 중합도의 비교)

  • Choi, Kung-Ho;Lee, Ju-Hyun;Park, Ho-Won
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.2
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    • pp.280-289
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    • 2004
  • Adequate polymerization is a crucial factor in obtaining optimal physical properties and clinical performance of resin composite restorative materials. The purpose of this study was to determine the effectiveness of shade and depth on dental composite resin polymerized with plasma arc curing unit employing FTIR and microhardness. From this experiment, the following results were obtained : 1. The light transmission and microhardness by mode 6 in plasma arc curing were similar to by 20 secs in halogen light curing. 2. The experimental groups of A1, A2, A3, A3.5 were not signifcant difference to light transmission and microhardness on surface and 2mm depth, but were significant difference on 3mm and 4mm depth. Especially light transmission and microhardness were small in darker shade and deeper thickness. 3. Compared with depth cure, uncured monomer amount increased at more than 2mm depth. 4. The light transmission by FTIR and polymerization by microhardness were significant corelation.

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The Study on the Sim(心) in Buddhism Medicine, Sasang Constitutional Medicine, and Oriental Medicine for construction of mind and body cure (심신치유를 위한 불교의학, 사상의학, 한의학에서의 심(心)의 연구)

  • Kim, Geun-Woo;Park, Seong-Sik
    • Journal of Oriental Neuropsychiatry
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    • v.23 no.1
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    • pp.1-15
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    • 2012
  • Objectives : The objective of this study is the Basic research for mind and body cure protocol construction through the Sim(心) study at Buddhism Medicine, Constitutional Medicine, and Oriental Medicine. Methods : 1. The Sim(心) in Buddhism is a target of spiritual culture and subjective awareness of An ascetic person in interior psychology. In this research, the Sim(心) has been modified within a concept of Early Buddhism and You-sic in order to have medical logicality. 2. Since the study deep into Sim(心) within Confucianism has various aspects, each Confucian's theory argument or era. We limited the significance of the Sim(心) to be associated with the category of the Sim(心) in Sasang Constitutional Medicine which is a product of practical Confucianism. 3. The criteria of debate for the Sim(心) is based on the "Hwang-je-nae-gyoung", because "Hwang-je-nae-gyoung" is founded to definite the term regarding spirit or mind in Oriental medicine Results : 1. "Hwang-je-nae-gyoung" which came from thought of You-Sic, thought of Taoism, and Early Buddhism becomes the theoretical basis for the Sim(心) in Buddhism Medicine, Sasang Constitutional Medicine, and Oriental Medicine. 2. The Sim(心) in the mind psychology of Buddhism Medicine, Sasang Constitutional Medicine, and Oriental Medicine has active aspects. but the visual thing // There are visual aspects being contrasted with 'Sim(心)' of mind psychology and aspects of activity in Buddhism medicine, Sasang constitutional Medicine and Oriental Medicine; which are 'Hrd', 'Hrdaya', 'four-large' 'five base', 'chin, chest, navel and abdomen', 'head, shoulder, waist and buttocks' consisting 'the body', and the heart and 'four interorgans' from the study of symbolical interorgans). In Buddhism Medicine, Sim(心)'s Epistemology is the most extensively understood fact about 'Sim(心)', and for Sasang Constitutional Medicine and Oriental Medicine. 'Sim(心)' is limited as an 'Element' that comprises the body. 3. The Functional area of the Sim(心) in the Buddhism Medicine, Sasang Constitutional Medicine, Oriental Medicine is composed with 'consciousness(意識)' 'manas-vij_na(末那識)', '_aya-vij_na(阿賴耶識)', 'mind greed(心欲)', 'Li(理)' and 'Sin(神)', about the interpretive area of 'Sim(心)', 'Sin(神)' of Oriental medicine is the most comprehensive concept, and on the side of the depth of 'thinking' and 'consciousness', '_aya-vij_na(阿賴耶識)' from Buddhism Medicine in the key point. 4. The Sim(心) in the Buddhism Medicine, Sasang Constitutional Medicine, has the positive and negative aspects, such as the 'Dukkha(煩惱)' and A merciful heart or Human Sim(心) and Taoism Sim(心).

Optimization of Elastic Modulus and Cure Characteristics of Composition for Die Attach Film (다이접착필름용 조성물의 탄성 계수 및 경화 특성 최적화)

  • Sung, Choonghyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.4
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    • pp.503-509
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    • 2019
  • The demand for smaller, faster, and multi-functional mobile devices in increasing at a rapidly increasing rate. In response to these trends, Stacked Chip Scale Package (SCSP) is used widely in the assembly industry. A film type adhesive called die attach film (DAF) is used widely for bonding chips in SCSP. The DAF requires high flowability at high die attachment temperatures for bonding chips on organic substrates, where the DAF needs to feel the gap depth, or for bonding the same sized dies, where the DAF needs to penetrate bonding wires. In this study, the mixture design of experiment (DOE) was performed for three raw materials to obtain the optimized DAF recipe for low elastic modulus at high temperature. Three components are acrylic polymer (SG-P3) and two solid epoxy resins (YD011 and YDCN500-1P) with different softening points. According to the DOE results, the elastic modulus at high temperature was influenced greatly by SG-P3. The elastic modulus at $100^{\circ}C$ decreased from 1.0 MPa to 0.2 MPa as the amount of SG-P3 was decreased by 20%. In contrast, the elastic modulus at room temperature was dominated by YD011, an epoxy with a higher softening point. The optimized DAF recipe showed approximately 98.4% pickup performance when a UV dicing tape was used. A DAF crack that occurred in curing was effectively suppressed through optimization of the cure accelerator amount and two-step cure schedule. The imizadole type accelerator showed better performance than the amine type accelerator.

EFFECTS OF VARIOUS ETCHING TIMES ON DEPTH OF ETCH AND SHEAR BOND STRENGTH OF AN ORTHODONTIC RESIN TO BOVINE ENAMEL (부식시간이 소의 법랑질 부식깊이와 교정용 레진의 전단결합강도에 미치는 영향)

  • Kim, Jeong-Hoon;Lee, Ki-Soo;Park, Young-Guk
    • The korean journal of orthodontics
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    • v.23 no.1 s.40
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    • pp.75-88
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    • 1993
  • Recent reports indicate that shorter etching times than 60 seconds can be adopted without affecting the bond strength and clinical disadvantages. The purpose of this in vitro study was to compare the shear bone strength and to measure depth of etch at different etching time length. One hundred and eight extracted bovine lower central incisors were embedded each in a tooth cup with cold-cure acrylic resin. The facial surfaces of the teeth were ground wet with 600-, 800-, 1000-, and 1200-grit Sic papers, and finally polished with a water slurry of extrafine silicon carbide powder, washed with tap water, and dried with hot air. Nine groups of nine prepared teeth were etched with a commercial($38\%$ phosphoric acid solution) for 0, 5, 10, 15, 20, 30, 60, 90, and 120 seconds, respectively, rinsed with tap water, and dried with hot air. One conditioned teeth from every group was selected randomly for the scanning electron microscopic examination, and the remaining eight teeth of the groups were used for measuring the push shear bond strength after bonding brackets and immensing them in the $36.5^{\circ}C$ water for 24 hours. Another nine groups of three teeth were used for measuring the depth of etch and surface roughness with a surface profilometer. after pieces of adhesive tape of 3mm inner diameter positioned on the ground enamel surfaces, and etched with the above mentioned. The data obtained form the above expeiments were analysed statistically with one way ANOVA and Dunkan's multiple range test with the $95\%$ confidence level. The results and conclusion of the study were as follows; 1. The results of shear bond strength for the given experimental etching times were not statistically different, but showed the tendency of decreasing shear bone strength after over 60 seconds etching times. 2. On the scanning election microscopic examination, it was observed that the morphological patterns of etched enamel surface for 5 to 20 seconds were similar and consitent, and those for 30 to 120 seconds showed increasing over-etched patterns depending on the length of etching times. 3. The depth of etch was increased almost proportionally by the length of etching times, but it was not associated with the shear bond strength. 4. The surface roughness increased depending on the length of etching times, but it was not associated with the shear bond strength. 5. This experiment indicated that proper etching time with $38\%$ phosphoric acid solution is in the range of 5 to 30 seconds.

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Effect of Qigong Training in a University Student's Physical, Mental Health and Self-esteem (기공 수련이 대학생의 육체적, 정신적 건강 및 자존감에 미치는 영향)

  • Kim, Ki-Jin;Han, Chang-Hyun;Lee, Sang-Nam;Kwon, Young-Kyu;Choi, Sun-Mi
    • Korean Journal of Oriental Medicine
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    • v.14 no.2
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    • pp.67-73
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    • 2008
  • Background: Qigong is one of energy-healing intervention used to prevent and cure ailments and to improve health through regular practice. Although Qigong-neither itself nor its postulated mechanism of action-is within the paradigm of modern Western medical science, effects on the human body could be possible. Objectives: This study aims to know effect of Qigong training in a University student's physical, mental health and self-esteem. Method: There are 120 students who take a Yangsaengkigong(養生氣功) course in D University college of oriental medicine during four weeks beginning in April 10th 2008. I researched 41 of them trained about effect of Qigong training. Result: Qigong training made significant change in self-esteem measurement and SCL-90-R. And there wasn't significant change in KHP and happiness index. Conclusions: The depth study for the each Qigong is needed. Specifically, I think it should be a clinical studies and qualitative research methods for evaluation are needed.

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A Theoretical Model of Hope Enhancing the Cancer Patients just after Surgery: Realistic Hope (수술 직후 암 환자의 희망증진 간호를 위한 이론 모델 개발 : 현실적 희망)

  • Kim, Dal Sook;Park, In Sook
    • Korean Journal of Adult Nursing
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    • v.18 no.1
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    • pp.115-124
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    • 2006
  • Purpose: The purpose of this study was to propose a theoretical model of hope commonly held by the cancer patients just after surgery, under the assumptions that hope of those patients is not only realistic and disease oriented but in dialectical circulation. Method: A theoretical model was generated through 4 steps: exploring a hope structure by synthesizing the relevant hope structures expressed in Kim and Tae's studies, in-depth literature review, examining the meanings of the concepts consisted of the structure in use and their causal relations in logical adequacy, proposing a theoretical structure through synthesizing the causal relations, and diagramming the structure. Results: The proposed theoretical model involves concepts such as Cancer Related Uncertainty (CRU), Efforts to Find out the Possibility of Cure or Recovery (EFPCR), and Hopefulness or Hopelessness. The 'EFPCR' is stipulated as 'Behaviors Related to Looking for Evidences or Cues (BRLEC)' and 'Formation of Cognitive Schema (FCS)'. In the model, Hopefulness is directly influenced by 'CRU in low', which is affected by 'FCS in good' from the result of EFPCR started with 'CRU in increase' while 'CRU with increase' from the result from EFPCR has direct effect on Hopelessness. Conclusion: The theoretical model would be used to enhancing hope of the cancer patients in post-operation.

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