• Title/Summary/Keyword: cure density

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Power density of light curing units through resin inlays fabricated with direct and indirect composites (직접수복용 레진과 기공용 레진으로 제작한 레진 인레이를 투과한 광중합기의 광강도)

  • Chang, Hoon-Sang;Lim, Young-Jun;Kim, Jeong-Mi;Hong, Sung-Ok
    • Restorative Dentistry and Endodontics
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    • v.35 no.5
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    • pp.353-358
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    • 2010
  • Objectives: The purpose of this study was to measure the power density of light curing units transmitted through resin inlays fabricated with direct composite (Filtek Z350, Filtek Supreme XT) and indirect composite (Sinfony). Materials and Methods: A3 shade of Z350, A3B and A3E shades of Supreme XT, and A3, E3, and T1 shades of Sinfony were used to fabricate the resin inlays in 1.5 mm thickness. The power density of a halogen light curing unit (Optilux 360) and an LED light curing unit (Elipar S10) through the fabricated resin inlays was measured with a hand held dental radiometer (Cure Rite). To investigate the effect of each composite layer consisting the resin inlays on light transmission, resin specimens of each shade were fabricated in 0.5 mm thickness and power density was measured through the resin specimens. Results: The power density through the resin inlays was lowest with the Z350 A3, followed by Supreme XT A3B and A3E. The power density was highest with Sinfony A3, E3, and T1 (p < 0.05). The power density through 0.5 mm thick resin specimens was lowest with dentin shades, Sinfony A3, Z350 A3, Supreme XT A3B, followed by enamel shades, Supreme XT A3E and Sinfony E3. The power density was highest with translucent shade, Sinfony T1 (p < 0.05). Conclusions: Using indirect lab composites with dentin, enamel, and translucent shades rather than direct composites with one or two shades could be advantageous in transmitting curing lights through resin inlays.

Oriental Medicines Effects on Cure and Prevention of an Obesity(VII) (비만치료 및 예방에 대한 한약의 효능 연구(VII) -체감행혈억이인탕가옥미가 비만유도 흰쥐의 생화학적 변화에 미치는 영향-)

  • Kim Sang Chan;Kwon Young Kyu;Kim Youn Sub;Byun Sung Hui
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.5
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    • pp.1001-1008
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    • 2002
  • This present study was carried out to investigate the body weight-regulatory effects of Chekamhanghyuluiyiin-tang plus Zeae Stigma in high fat diet-induced obese rats. Control group rats were fed with high fat diet and administered normal saline for 8weeks. Experimental groups rats were fed with high fat diet and administered extract of 2 kind of Chekamhanghyuluiyiin-tang plus Zeae Stigma each other for 8 weeks. And observed that, body weight of rats and total cholesterol, triglyceride, free fatty acid, total lipid, phospholipid, high density lipoprotein(HDL)-cholesterol, low density lipoprotein(LDL)-cholesterol in serum of rats, and glucose, insulin of rats. The results were as follows; There were significant decrease of serum free ratty acid level in 4CH/sub 5/ group. There were significant decrease of serum glucose level in 4CH/sub 10/ group. According to above mentioned results, Chekamhanghyuluiyiin-tang plus Zeae Stigma was expected to be applied to the prevention or treatment of obesity and its complications.

Silicone Injection Mold & Molding Technology for Super-hydrophobic Curved Surface (초발수 곡면표면 실리콘 사출금형성형기술)

  • Lee, Sung-Hee;Kang, Jeong-Jin;Lee, Jong-Won;Hong, Seok-Kwan;Ko, Jong-Soo;Lee, Jae-Hoon;Noh, Ji-Whan
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.1
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    • pp.13-18
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    • 2012
  • In this study, silicone injection molding technology with curved thermoplastic insert was developed to produce super-hydrophobic surface. Thermoplastic insert part and injection mold design of base plastic cover were performed to produce cost effective hydrophobic surface part. An optimization process of part thickness for thermoplastic insert part was performed with transient thermal analysis under silicone over-molding process condition. Structural thermal analysis of silicone injection mold was also performed to obtain uniform temperature condition on the surface of micro-patterned mold core. Super-hydrophobic surface for the silicone injection molded part with thermoplastic insert could be verified from the measurement of contact angle. It was shown that the averaged contact angle was over $140^{\circ}$.

Curing Behavior of Phenolic Resin with Humid Atmosphere on The Porous $ZrO_2$ ceramics

  • Yun, Sang-Hyeon;Kim, Jang-Hun;Kim, Ju-Yeong;Lee, Jun-Tae;Lee, Hui-Su
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.05a
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    • pp.57.1-57.1
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    • 2011
  • The effects of relative humidity on the properties of the porous $ZrO_2$ ceramics were investigated in terms of the curing behavior of phenolic resin as a binder. The $ZrO_2$ powders containing 5wt% of phenolic resin were conditioned in a consistent chamber condition at a temperature of $50^{\circ}C$ and different humidity levels (25, 50, 75, and 95%) for 1 h. The exposure of humid atmosphere caused changes of density and microstructure in the green bodies. The higher level the powders were exposed to the humid atmosphere, the lower green density was obtained and the more irregular microstructure was observed due to aggregation by the curing of phenolic resin. After firing, the porosity of specimens has risen from 35.7% to 38.1% and Young's modulus has declined in response to the variation of green density. These results could be explained by the degree of resin cure which was associated with the area under the exothermic peak enclosed by a baseline of DSC thermogram curve. Also, the curing behavior of phenolic resin according to relative humidity has been confirmed by decrease of ether groups which have interacted with the phenolic-OH group and the hexamine as a curing agent. Consequently, it could be demonstrated that increase the relative humidity during fabrication of porous $ZrO_2$ diminished the compaction and properties of specimens after firing owing to curing of phenolic resin.

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Properties of Rubbers and Coated Fabrics according to Different Cross-linking Density of Coating Agent (코팅제의 가교 밀도에 따른 고무와 코팅원단의 물성 변화)

  • Suhong Kim;Kisuk Sung;Doohyun Baik
    • Textile Coloration and Finishing
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    • v.35 no.1
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    • pp.8-19
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    • 2023
  • Silicone rubber is widely used in most industries due to diverse advantages like heat stability, UV stability, durability, chemical resistance, environment friendliness, inertness and so on. But there is limitation to expand applications due to relatively weak rubber strengths such as tensile strength and tear strength, especially in fabric coating applications. The purpose of this study is to find influence of coating agent on performances of rubber and coated fabrics and their correlation according to different crosslinking densities of silicone rubbers. Addition cure type of silicones were formulated using crosslinked MQ-type silicone resin consisting of M (R3SiO1/2) and Q (SiO4/2) and linear polymers. Raw materials used were; 1) linear vinyl endblocked polymers and vinyl functional MQ resin as main polymers, 2) linear silicone hydride polymers as crosslinkers, 3) platinum catalyst and 4) inhibitor to control curing speed. Rubber specimens were prepared to check mechanical strength using universal testing machine (UTM). Crosslinking density was calculated using Flory-Rhener equation using solvent swelling method. Differential scanning calorimetry (DSC) and scanning electron microscope (SEM-EDS) were used to characterize rubbers. Consequently, it was found that physical properties of silicone rubbers and coated fabrics can be expected by crosslinking density of rubbers. Silicone rubber formulations that contain 20 ~ 30 wt% of vinyl MQ resin showed strongest balanced performances.

Power density of various light curing units through resin inlays with modified layer thickness

  • Hong, Sung-Ok;Oh, Yong-Hui;Min, Jeong-Bum;Kim, Jin-Woo;Lee, Bin-Na;Hwang, Yun-Chan;Hwang, In-Nam;Oh, Won-Mann;Chang, Hoon-Sang
    • Restorative Dentistry and Endodontics
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    • v.37 no.3
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    • pp.130-135
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    • 2012
  • Objectives: The purpose of this study was to enhance curing light penetration through resin inlays by modifying the thicknesses of the dentin, enamel, and translucent layers. Materials and Methods: To investigate the layer dominantly affecting the power density of light curing units, resin wafers of each layer with 0.5 mm thickness were prepared and power density through resin wafers was measured with a dental radiometer (Cure Rite, Kerr). The dentin layer, which had the dominant effect on power density reduction, was decreased in thickness from 0.5 to 0.1 mm while thickness of the enamel layer was kept unchanged at 0.5 mm and thickness of the translucent layer was increased from 0.5 to 0.9 mm and vice versa, in order to maintain the total thickness of 1.5 mm of the resin inlay. Power density of various light curing units through resin inlays was measured. Results: Power density measured through 0.5 mm resin wafers decreased more significantly with the dentin layer than with the enamel and translucent layers (p < 0.05). Power density through 1.5 mm resin inlays increased when the dentin layer thickness was reduced and the enamel or translucent layer thickness was increased. The highest power density was recorded with dentin layer thickness of 0.1 mm and increased translucent layer thickness in all light curing units. Conclusions: To enhance the power density through resin inlays, reducing the dentin layer thickness and increasing the translucent layer thickness would be recommendable when fabricating resin inlays.

A Study On the Retention Time Distribution with Plasma Damage Effect

  • Yi Jae Young;Szirmay Laszlo;Yi Cheon Hee
    • Proceedings of the IEEK Conference
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    • 2004.08c
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    • pp.460-462
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    • 2004
  • The control of the data retention time is a main issue for realizing future high density dynamic random access memory. There are several leakage current mechanisms in which the stored data disappears. The mechanisms of data disappear is as follow, 1 )Junction leakage current between the junction, 2) Junction leakage current from the capacitor node contact, 3)Sub-threshold leakage current if the transfer transistor is affected by gate etch damage etc. In this paper we showed the plasma edge damage effect to find out data retention time effectiveness. First we measured the transistor characteristics of forward and reverse bias. And junction leakage characteristics are measured with/without plasma damage by HP4145. Finally, we showed the comparison TRET with etch damage, damage_cure_RTP and hydrogen_treatment. As a result, hydrogen_treatment is superior than any other method in a curing plasma etch damage side.

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A Periosteal Fibrosarcoma in a Puppy Dog (강아지에서의 골막섬유육종 증례)

  • 김순신;김휘율;장화석;송영성;김성미;김혜진;서정향
    • Journal of Veterinary Clinics
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    • v.21 no.1
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    • pp.52-57
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    • 2004
  • A 4 months old Golden retriever male dog was referred. By the history taking, it was kwon that the mass has been formed at the parietal region of the patient after fourth prevention inoculation. The appetite, urination and excretion were normal. The mass confirmation which was limited in the parietal region, did not seem to be enlargement of lymph node from physical examination palpation. Complete blood count and serum biochemical profiles were consistent with mild lymphocytosis, mild monocytosis, anisocytosis, regenerative anemia and elevated ALP, CPK. Survey radiographs indicated a mixed density in parietal region. We performed surgical resection and chemotherapy for cure and biopsy. Histological finding was periosteal fibrosarcoma. The application of cisplatin was topically used in operation site. Up to now the indication of recurrence is not visible.

Primary Mediastinal Liposarcoma - 1 Case Report - (원발성 종격동 지방육종 -1예 보고 -)

  • Lee, Seong-Yun;Hong, Eun-Gyeong;Ji, Haeng-Ok
    • Journal of Chest Surgery
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    • v.22 no.6
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    • pp.1061-1069
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    • 1989
  • A case of liposarcoma was reported in 52 year-old female. She had the operation history due to mediastinal lipoma at other Hospital before 26 months ago. Chest X-ray revealed a huge soft tissue mass- density at the entire right lung field, and left middle and lower lung field at admission. At the lateral film, the mass was located in the anterior and middle mediastinum. Transsternal bilateral thoracotomy was performed, followed by extirpation of liposarcoma, wedge resection of superior vena cava, angioplasty of superior vena cava, and then partial pericardiectomy. The post-operative treatment was 5500 rad irradiation. Post-operative course was uneventful, that was noticed by OPD follow-up for 10 months. Primary liposarcoma of the mediastinum is very rare tumor. This tumor grows to an enormous size, and symptoms are referable to compression of the contiguous intrathoracic structures. The treatment of choice is surgery in all cases. Such an approach serves to establish a tissue diagnosis, to relieve the patients* symptoms, and may results in a cure sometimes. Radiotherapy or/and chemotherapy seems to be ineffective, but should be further studied.

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The Study on the Dependence of Cure Condition for Reinforcing Filler (보강성충전제의 가황조건 의존성에 관한 연구)

  • Lee, Seag
    • Elastomers and Composites
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    • v.33 no.2
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    • pp.75-82
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    • 1998
  • The purpose of this experimental study was to investigate the effects of vulcanization condition on the properties of reinforced rubbers. Rubber reinforcing ability of carbon black was more efficient than other fillers, but tensile properties were not affected by vulcanization condition while vulcanization condition affected the physical properties of rubber compounds with silica and silane treated slica. It was found that silica and silane treated silica filled rubber compounds showed good dynamic properties, rebound, heat build-up, 0 and $60^{\circ}C$ tan $\delta$ compared with carbon black filled rubber compounds. Carbon black filled rubber compounds were higher than silica and silane treated silica filled rubber compounds in total crosslinking density by vulcanization condition. By analysis of crosslinking type, polysulfide crosslinking was the highest in the carbon black filled rubber compounds with decreasing the ratio of sulfur to accelerator, monosulfide crosslinking was the highest in the silane treated silica filled compounds with in-creasing the ratio of sulfur to accelerator.

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