• Title/Summary/Keyword: Covering thickness

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Effect of infection control barrier thickness on light curing units (감염 조절용 차단막의 두께가 광중합기의 중합광에 미치는 영향)

  • Chang, Hoon-Sang;Lee, Seok-Ryun;Hong, Sung-Ok;Ryu, Hyun-Wook;Song, Chang-Kyu;Min, Kyung-San
    • Restorative Dentistry and Endodontics
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    • v.35 no.5
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    • pp.368-373
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    • 2010
  • Objectives: This study investigated the effect of infection control barrier thickness on power density, wavelength, and light diffusion of light curing units. Materials and Methods: Infection control barrier (Cleanwrap) in one-fold, two-fold, four-fold, and eightfold, and a halogen light curing unit (Optilux 360) and a light emitting diode (LED) light curing unit (Elipar FreeLight 2) were used in this study. Power density of light curing units with infection control barriers covering the fiberoptic bundle was measured with a hand held dental radiometer (Cure Rite). Wavelength of light curing units fixed on a custom made optical breadboard was measured with a portable spectroradiometer (CS-1000). Light diffusion of light curing units was photographed with DSLR (Nikon D70s) as above. Results: Power density decreased significantly as the layer thickness of the infection control barrier increased, except the one-fold and two-fold in halogen light curing unit. Especially, when the barrier was four-fold and more in the halogen light curing unit, the decrease of power density was more prominent. The wavelength of light curing units was not affected by the barriers and almost no change was detected in the peak wavelength. Light diffusion of LED light curing unit was not affected by barriers, however, halogen light curing unit showed decrease in light diffusion angle when the barrier was four-fold and statistically different decrease when the barrier was eight-fold (p < 0.05). Conclusions: It could be assumed that the infection control barriers should be used as two-fold rather than one-fold to prevent tearing of the barriers and subsequent cross contamination between the patients.

Actual Clothing Style of Middle school girls According to Self-perception of Their Body Size (여중생의 신체 인식에 따른 착의 의복형태에 관한 연구)

  • Park Woo-Mi;Wee Eun-Hah
    • Journal of Korean Home Economics Education Association
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    • v.18 no.1 s.39
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    • pp.113-125
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    • 2006
  • The purpose of this study was to examine the effects of perception of body size on actual clothing style in middle school girls. To achieve this, this study analyzed self-perception of body size, aspired clothing style, and actual clothing style. By classifying groups into thin and thick, the difference in clothing style according to groups was also analyzed. Subjects of this study were middle school girls in Gwangju and 219 responses were collected from real body measurement and questionnaires. WIN SPSS+10.0 package was used to obtain results. Results are as follows: 1. For the self-perception of body size, middle school girls perceived much thicker in the lower body than the upper body. And they were unsatisfactory about the lower body which was perceived thick. 2. In the correlation of actual and aspired clothing style of middle school girls, they wore a aspired clothing style actually. Their actual or aspired upper clothing style was to cover the skin, exposing or covering a body silhouette. Their lower clothing style was a slacks type that covers a body silhouette and the skin. 3. In selecting actual clothing styles, middle school girls were somewhat affected by self-perceived body size. But they did not prefer the clothing styles perceived thick in girth or big in width in exposing the skin or a body silhouette. On the other hand, as it was perceived long, wearing was increased. frequently wore the upper and lower clothing styles of exposing the skin or a body silhouette than the thick group. But both groups wore the clothing styles of covering the skin or a body silhouette regardless of their thinness and thickness. And when wearing the clothing style of exposing neck and shoulder, middle school girls considered actual body size more than self-perceived size. On the other hand, when wearing the clothing style of exposing arms and silhouette by fitted legs, they considered self-perceived body size more.

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A Study on the Application of RTLS Technology for the Automation of Spray-Applied Fire Resistive Covering Work (뿜칠내화피복 작업 자동화시스템을 위한 RTLS 기술 적용에 관한 연구)

  • Kim, Kyoon-Tai
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.5
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    • pp.79-86
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    • 2009
  • In a steel structure, spray-applied fire resistive materials are crucial in preventing structural strength from being weakened in the event of a fire. The quality control of such materials, however, is difficult for manual workers, who can frequently be in short supply. These skilled workers are also very likely to be exposed to environmental hazards. Problems with construction work such as this, which are specifically the difficulty of achieving quality control and the dangerous nature of the work itself, can be solved to some degree by the introduction of automated equipment. It is, however, very difficult to automate the work process, from operation to the selection of a location for the equipment, as the environment of a construction site has not yet been structured to accommodate automation. This is a fundamental study on the possibility of the automation of spray-applied fire resistive coating work. In this study, the linkability of the cutting-edge RTLS to an automation system is reviewed, and a scenario for the automation of spray-applied fire resistive coating work and system composition is presented. The system suggested in this study is still in a conceptual stage, and as such, there are many restrictions still to be resolved. Despite this fact, automation is expected to have good effectiveness in terms of preventing fire from spreading by maintaining a certain level of strength at a high temperature when a fire occurs, as it maintains the thickness of the fire-resistive coating at a specified level, and secures the integrity of the coating with the steel structure, thereby enhancing the fire-resistive performance. It also expected that if future research is conducted in this area in relation to a cutting-edge monitoring TRS, such as the ubiquitous sensor network (USN) and/or building information model (BIM), it will contribute to raising the level of construction automation in Korea, reducing costs through the systematic and efficient management of construction resources, shortening construction periods, and implementing more precise construction

A New Method for Cultivation of Sclerotium of Grifola umbellata

  • Choi, Kyung-Dal;Lee, Kyung-Tae;Shim, Jae-Ouk;Lee, Youn-Su;Lee, Tae-Soo;Lee, Sang-Sun;Guo, Shun-Xing;Lee, Min-Woong
    • Mycobiology
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    • v.31 no.2
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    • pp.105-112
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    • 2003
  • Sclerotia of Grifola umbellata were cultivated by two methods such as burying and root inoculation methods. The sclerotia of G. umbellata produced by the burying method were $6.0{\sim}6.8{\times}3.4{\sim}4.6{\times}1.8{\sim}1.9cm$(Width$\times$Length$\times$Thickness) in size and $17.3{\sim}19.6g$ in weight, respectively. Their increase rate was $1.10{\times}1.12$ times. On the other hand, the sclerotia cultivated by the root inoculation method were $18.3{\sim}31.5{\times}12.5{\sim}26.4{\times}3.1{\sim}3.7cm(W{\times}L{\times}T)$ in size and $219.1{\sim}576.6g$ in weight, respectively. Their growth increment was $11.18{\sim}39.77$ times. The rhizomorphs of Armillaria mellea were developed with a high density under fallen leaves layer covering cultivation site, and distributed mainly between soil surface and soil depth of about 10 cm as well as colonized prominently on the inoculated wood logs. Fungal interaction between G. umbellata and A. mellea were observed mainly in the stage of white sclerotium of G. umbellata. The sclerotia of G. umbellata which were developed newly and harvested in the root inoculation method were twined with root hairs of host tree and rhizomorphs of A. mellea. The sclerotia of G. umbellata decomposing root hairs of host tree were confirmed through SEM examination. Physiochemical characteristics of soil in all cultivation sites had no significant differences. Soil pH were in the range of pH $3.98{\sim}4.40$. Organic matters were the range of $17.97{\sim}23.86%$ and moisture contents of soil were $12.00{\sim}18.20%$. Soil temperatures showed $12.9{\sim}13.8^{\circ}C$ in November and $22.0{\sim}23.9^{\circ}C$ in August, respectively. In conclusion, the root inoculation method seems to be a practical method for cultivating sclerotia of G. umbellata due to its many advantages such as simplicity of inoculation process, shortening of cultivation periods and facility of harvest.

Neural correlations of familiar and Unfamiliar face recognition by using Event Related fMRI

  • Kim, Jeong-Seok;Jeun, Sin-Soo;Kim, Bum-Soo;Choe, Bo-Young;Lee, Hyoung-Koo;Suh, Tae-Suk
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2003.09a
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    • pp.78-78
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    • 2003
  • Purpose: This event related fMRI study was to further our understanding about how different brain regions could contribute to effective access of specific information stored in long term memory. This experiment has allowed us to determine the brain regions involved in recognition of familiar faces among non familiar faces. Materials and Methods: Twelve right handed normal, healthy volunteer adults participated in face recognition experiment. The paradigm consists of two 40 familiar faces, 40 unfamiliar faces and control base with scrambled faces in a randomized order, with null events. Volunteers were instructed to press on one of two possible buttons of a response box to indicate whether a face was familiar or not. Incorrect answers were ignored. A 1.5T MRI system(GMENS) was employed to evaluate brain activity by using blood oxygen level dependent (BOLD) contrast. Gradient Echo EPI sequence with TR/TE= 2250/40 msec was used for 17 contiguous axial slices of 7mm thickness, covering the whole brain volume (240mm Field of view, 64 ${\times}$ 64 in plane resolution). The acquired data were applied to SPM99 for the processing such as realignment, normalization, smoothing, statistical ANOVA and statistical preference. Results/Disscusion: The comparison of familiar faces vs unfamiliar faces yielded significant activations in the medial temporal regions, the occipito temporal regions and in frontal regions. These results suggest that when volunteers are asked to recognize familiar faces among unfamiliar faces they tend to activate several regions frequently involved in face perception. The medial temporal regions are also activated for familiar and unfamiliar faces. This interesting result suggests a contribution of this structure in the attempt to match perceived faces with pre existing semantic representations stored in long term memory.

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Studies on the Physical Properties of Vinyl Monomers Graft Polymerized Silk Fibre (비닐 단량체 그라프트 중합견의 물성에 관한 연구)

  • 이용우;송기언
    • Journal of Sericultural and Entomological Science
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    • v.27 no.1
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    • pp.47-50
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    • 1985
  • The physical properties of graft polymerized silk fibre were investigated with various vinyl monomers. 1. The graft polymerization of styrene and methyl methacrylate onto raw silk reduced the tenacity and elongation of raw silk due to fixation of sericin covering silk fibre in, but the styrene grafting was more effective for sericin fixation of raw silk than the methyl methacrylate one. 2. The water absorbability of glycidyl methacrylate grafted silk increased 14.6% greater than that of methyl methacrylate grafted silk at the same degree of grafting polymerization. 3. The degree of grafting polymerization was increased mostly with ethylene glycol methacrylate. The water absorbability of ethylene glycol methacrylate grafted silk was higher than that of glycidyl methacrylate or ethyl acrylate grafted silk. But the grafted silk fabric increased the fabric flexural rigidity which was negatively related with the favorability of fabric hand-touch, as compared with that of nongrafted silk fabric. 4. The evenness of graft polymerization could be improved by agitating the polymerization bath at the fixed interval by reducing the inter size deviation of grafted silk skein and the thickness deviation of grafted silk fabric.

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Absorbable Guided Bone Regeneration Membrane Fabricated from Dehydrothermal Treated Porcine Collagen (Dehydrothermal Treatment로 제작한 흡수성 콜라겐 골유도재생술 차단막)

  • Pang, Kang-Mi;Choung, Han-Wool;Kim, Sung-Po;Yang, Eun-Kyung;Kim, Ki-Ho;Kim, Soung-Min;Kim, Myung-Jin;Jahng, Jeong-Won;Lee, Jong-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.33 no.2
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    • pp.112-119
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    • 2011
  • Purpose: Collagen membranes are used extensively as bioabsorbable barriers in guided bone regeneration. However, collagen has different effects on tissue restoration depending on the type, structure, degree of cross-linking and chemical treatment. The purpose of this study was to evaluate the inflammatory reaction, bone formation, and degradation of dehydrothermal treated porcine type I atelocollagen (CollaGuide$^{(R)}$) compared to of the non-crosslinked porcine type I, III collagen (BioGide$^{(R)}$) and the glutaldehyde cross-linked bovine type I collagen (BioMend$^{(R)}$) in surgically created bone defects in rat mandible. Methods: Bone defect model was based upon 3 mm sized full-thickness transcortical bone defects in the mandibular ramus of Sprague-Dawley rats. The defects were covered bucolingually with CollaGuide$^{(R)}$, BioMend$^{(R)}$, or BioGide$^{(R)}$ (n=12). For control, the defects were not covered by any membrane. Lymphocyte, multinucleated giant cell infiltration, bone formation over the defect area and membrane absorption were evaluated at 4 weeks postimplantation. For comparison of the membrane effect over the bone augmentation, rats received a bone graft plus different covering of membrane. A $3{\times}4$ mm sized block graft was harvested from the mandibular angle and was laid and stabilized with a microscrew on the naturally existing curvature of mandibular inferior border. After 10 weeks postimplantation, same histologic analysis were done. Results: In the defect model at 4 weeks post-implantation, the amount of new bone formed in defects was similar for all types of membrane. Bio-Gide$^{(R)}$ membranes induced significantly greater inflammatory response and membrane resorption than other two membranes; characterized by lymphocytes and multinucleated giant cells. At 10 weeks postoperatively, all membranes were completely resorbed. Conclusion: Dehydrotheramal treated cross-linked collagen was safe and effective in guiding bone regeneration in alveolar ridge defects and bone augmentation in rats, similar to BioGide$^{(R)}$ and BioMend$^{(R)}$, thus, could be clinically useful.

L-shaped Slot Antenna for WLAN MIMO Application (무선랜 MIMO용 L-형 슬롯 안테나)

  • Song, Won-Ho;Nam, Ju-Yeol;Lee, Ki-Yong;Lee, Young-soon
    • Journal of Advanced Navigation Technology
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    • v.20 no.4
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    • pp.344-351
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    • 2016
  • In the present study, a dual-band multiple-input-multiple-output (MIMO) antenna covering WLAN frequency bands of 2.4 GHz (2.4 ~ 2.484 GHz) and 5 GHz (5.15 ~ 5.825 GHz) is newly presented to avoid use of decoupling structure for increasing isolation. The antenna consists of two L-shaped slots with n-shaped slots etched on the floating ground plane surrounded by open ended L-shaped slots which are placed in the left and right corner of PCB respectively. The proposed antenna is designed and fabricated on one side of FR4 substrate with dielectric constant of 4.3, thickness of 1.6 mm, and size of $50{\times}50mm2$. It has been observed that the measured impedance bandwidths ($S_{11}{\leq}-10dB$) are 0.3 GHz (2.28 ~ 2.58 GHz) in 2.4 GHz frequency band and 0.89 GHz (5.11 ~ 6 GHz) in 5 GHz frequency band respectively. In addition, It has been observed that the whole efficiency are more than 80 % in the whole operating frequency band and envelope correlation coefficient of the antenna is less than 0.05 as a very small value in spite of nothing of the decoupling structure.

Determination of Significance Threshold for Detecting QTL in Pigs (돼지의 QTL 검색을 위한 유의적 임계수준(Threshold) 결정)

  • Lee, H.K.;Jeon, G.J.
    • Journal of Animal Science and Technology
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    • v.44 no.1
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    • pp.31-38
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    • 2002
  • Interval mapping using microsatellite markers was employed to detect quantitative trait loci (QTL) in the experimental cross between Berkshire and Yorkshire pigs. In order to derive critical values (CV) for test statistics for declaring significance of QTL, permutation test (PT) of Churchill and Doerge method(1994) and the analytical method(LK) of Lander and Kruglyak(1995) were used by each trait and chromosome. 525 $F_2$ progeny phenotypes of five traits(carcass weight, loin eye area, marbling score, cholesterol content, last back fat thickness) and genotypes of 125 markers covering the genome were used. Data were analyzed by line cross regression interval mapping with an F-test every by 1cM. PT CV were based on 10,000 permutations. CV at genome-wise test were 10.5 for LK and ranged from 8.1 to 8.3 for PT, depending on the trait. CV, differed substantially between methods, led to different numbers of quantitative trait loci (QTL) to be detected. PT results in the least stringent CV compared at the same % level.

Scientific Analysis of Gilt-Bronze Plaquettes with Buddhist Images(Panbul) from Anapji Pond, Gyeongju (안압지 금동판불의 과학적 분석)

  • Yu, Heisun;Park, Haksoo;Shin, Yongbi
    • Conservation Science in Museum
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    • v.8
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    • pp.49-69
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    • 2007
  • This is about the scientific analysis of the 10 items of the gilt-bronze Panbul excavated from Anapji, Gyeongju. First, the composition of the Panbul was confirmed, using X-ray fluorescence spectrometer (XRF), and the patinas covering the surface of the Panbul were analyzed, using X-ray diffractometer (XRD). And the micro structures and gilt layer of the Panbul were investigated, using microscope and scanning electron microscope with energy dispersive spectrometer (SEM/EDS), and in order to investigate the internal conditions of the Panbul, X-radiography was conducted. As the result, it is found out that the material of the Panbul excavated from Anapji was the bronze of copper (86~95%) and tin (4~12%), and coated with gold. And cuprite (Cu2O) was detected from red patina of the gilt-bronze Panbul, and chalcocite(Cu2S) also was detected from the black patina. As the result of the observation of the micro structure through microscope, it is estimated that it was manufactured, using the wax molding method, and, judging from the fact that the thickness of gilt layer was not even, and that the groove had been filled, it was presumed that the amalgam coating method had been used, but some questions still remain, because mercury was not detected. Lastly, through the X-radiography, it was observed that the tiny round spots existed, which was presumed to have been generated during the casting.