• Title/Summary/Keyword: 석고법

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Indirect Anthropometry on Cast Model of Cleft Lip Nose: Comparison with Direct Anthropometry (구순열비 석고모형에서 간접인체계측법: 직접인체계측법과의 비교)

  • Han, Ki Hwan;Jeong, Hoi Joon;Jin, Hyun Seok;Kim, Jun Hyung;Son, Dae Gu
    • Archives of Plastic Surgery
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    • v.34 no.1
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    • pp.18-23
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    • 2007
  • Purpose: Anthropometry can be divided into two methods, direct anthropometry and indirect anthropometry. The most ideal and accurate method is a direct anthropometry. However, it is difficult to measure in the case of children because of poor cooperation, and it lacks re-productivity. Cast model has advantages of three dimensional featuring, inexpensive and easy fabrication. This study is conducted to find out an accuracy of indirect anthropometry on cast model by comparing it with direct anthropometry. Methods: Total 48 cleft lip nasal deformity patients (unilateral, 40; bilateral, 8) were included in this study. Cast models were made before surgery under general anesthesia with alginate impression material and model plaster. Eleven linear measurements among 7 landmarks were taken as direct anthropometry before surgery with Castroviejo spreading caliper. At the same time, indirect anthropometry on cast model was done at the same linear distances as well. Results: Of the total 11 linear measurements, both ala lengths, both columella lengths, nose width, projective distance between facial insertion points of the ala, projective distance between the alar base points, right nostril floor width, and columella width were statistically correlated between indirect anthropometry on cast model and direct anthropometry. However, the nasal tip protrusion and the left nostril floor width were not statistically correlated. Conclusion: Accuracy of indirect anthropometry on cast model can be influenced by cast model fabrication techniques and correct identification of landmarks. Nasal tip protrusion could be reduced by compression of the nasal tip in the process of cast model fabrication and nostril floor width can be varied by muscle relaxation of anesthetics and incorrect identification of subalare in cleft lip nasal deformity. If sufficient care is taken to make cast model and to define landmarks exactly, indirect anthropometry on cast model can be a reliable method as direct anthropometry.

Conservation Treatment on the Bamboo Sunblind from the No. 1 Catchment Site in Baesanseongji, Busan (부산 배산성지 1호 집수지 출토 대나무 발 수습 및 보존처리)

  • Park, Ji Hyeon;Park, Jung Hae;Lee, Kwang Hee;Seo, Yeon Ju;Park, Jung Wook;Kim, Soo Chul
    • Journal of Conservation Science
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    • v.37 no.5
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    • pp.536-544
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    • 2021
  • In the present study, safe management and value improvement of bamboo sunblind, which is an item of cultural heritage, were performed by adopting stable conservation treatment methods. The bamboo sunblind used in the present study was excavated from No. 1 catchment site in Baesanseongji, Busan. It was determined that the main material used to make the sunblind was bamboo, and herbal plants were used to weave the bamboo using lacquer as an adhesive agent. All contaminants and soil adhered to the sunblind was removed. Thereafter, the sunblind, which was recovered in the form of blocks, was washed separately after fixing it to a temporary plaster frame and to avoid the blocks from breaking during washing. Then, polyethylene glycol (PEG) impregnation was utilized for the reinforcement treatment. Based on the preliminary test results, the shape of the sunblind was fixed using a stainless-steel frame to prevent physical damage that may occur during the drying process. Thereafter, the bamboo sunblind was vacuum freeze-dried. PEG 20% (in ethyl alcohol) was applied as a surface treatment agent for stabilization the sunblind. After the surface treatment, the bamboo sunblind were joined together to fit the maximum width, and the rectangular shape of the sunblind was restored-as best as possible-while filling in the missing parts by maximizing the use of unknown members such as in the disturbed layers below bamboo sunblind surface. The conservation treatment was completed by fixing the bamboo sunblind into the fabricated frame.

Sound Absorption Rate and Sound Transmission Loss of Wood Bark Particle (목재수피 파티클의 흡음율과 음향투과손실)

  • Kang, Chun-Won;Jang, Eun-Suk;Jang, Sang-Sik;Kang, Ho-Yang;Kang, Seog-Goo;Oh, Se-Chang
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.4
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    • pp.425-441
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    • 2019
  • In this study, sound absorption capability and sound transmission loss of several kinds of target densities and thickness for six species of wood bark particle were estimated by the transfer function and transfer matrix methods. Resultantly, the mean sound absorption coefficient of a 100-mm thick Hinoki wood bark particle mat was 0.90 in the frequency range of 100-6400 Hz, whereas the mean sound absorption rate of a 50-mm thick Hinoki wood bark particle mat was 0.84 in the same frequency range. Particularly, at a thickness of 100 mm, it reached almost up to 100% in the frequency range of 1 KHz. The sound transmission losses of 100-mm thick Hinoki wood bark particle mat with a target density of 0.16 at 500 and 1000 Hz were 15.30 and 15.73 dB, respectively. When a 10-mm thick plywood was attached to the back of the wood particle mat, the sound transmission losses was increased by 20-30 dB. Wood bark can be used as an acoustical material owing to its high sound absorption rate and transmission loss.

A Basic Study on the Radiological Characteristics and Disposal Methods of NORM Wastes (공정부산물의 방사선적 특성과 처분방안에 관한 기본 연구)

  • Jeong, Jongtae;Baik, Min-Hoon;Park, Chung-Kyun;Park, Tae-Jin;Ko, Nak-Youl;Yoon, Ki Hoon
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.3
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    • pp.217-233
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    • 2014
  • Securing the radiological safety is a prerequisite for the safe management of the naturally occurring radioactive materials (NORM) which cannot be reused. This becomes a crucial focus of our R&D efforts upon the implementation of the Act on Protective Action Guidelines against Radiation in the Natural Environment. To secure the safety, the establishment of technical bases and procedures for securing radiological safety related to the disposal of NORM is required. Thus, it is necessary to analyze the characteristics, to collect the data, to have the radiological safety assessment methodologies and tools, to investigate disposal methods and facilities, and to study the effects of the input data on the safety for the NORM wastes. Here, we assess the environmental impact of the NORM waste disposal with respect to the major domestic and foreign NORM characteristics. The data associated with major industries are collected/analyzed and the status of disposal facilities and methodologies relevant to the NORM wastes is investigated. We also suggest the conceptual design concept of a landfill disposal facility and the management plan with respect to the major NORM wastes characteristics. The radionuclide pathways are identified for the atmospheric transport and leachate release and the environmental impact assessment methodology for the NORM waste disposal is established using a relevant code. The assessment and analysis on the exposure doses and excessive cancer risks for the NORM waste disposal are performed using the characteristics of the representative domestic NORM wastes including flying ash, phosphor gypsum, and redmud. The results show that the exposure dose and the excessive cancer risks are very low to consider any radiation effects. This study will contribute to development in the areas of the regulatory technology for securing radiological safety relevant to NORM waste disposal and to the implementation technology for the Act.

Study on the determination methods of the natural radionuclides (238U, 232Th) in building materials and processed living products (실내 건축자재 및 생활 가공제품 중 천연방사성핵종(238U, 232Th)의 농도 평가를 위한 분석법 연구)

  • Lee, Hyeon-Woo;Lim, Jong-Myoung;Lee, Hoon;Park, Ji-Young;Jang, Mee;Lee, Jin-Hong
    • Analytical Science and Technology
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    • v.31 no.4
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    • pp.149-160
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    • 2018
  • A large number of functional living products are being produced for eco-friendly or health-promoting purposes. In the manufacturing process, such products could be adulterated with raw materials with high radioactivity, such as monazite and tourmaline. Thus, it is essential to manage raw materials and products closely related to the public living. For proper management, an accurate radioactivity data of the processed products are needed. Therefore, it is essential to develop a rapid and validated analytical method. In this study, the concentration of the radioactive $^{238}U$ and $^{232}Th$ in building materials (e.g., tile, cement, paint, wall paper, and gypsum board) and living products (e.g., health products, textiles, and minerals) were determined and compared by ED-XRF and ICP-MS. By comparing the results of both methods, we confirmed the applicability of the rapid screening and precise analysis of ED-XRF and ICP-MS. In addition, $^{238}U$ and $^{232}Th$ levels were relatively lower in building materials than in living products. Particularly, $^{232}Th$ content in 6 of 47 living products exceeded (maximum $8.2Bq{\cdot}g^{-1}$) the standard limit of $^{232}Th$ content in raw material ($1.0Bq{\cdot}g^{-1}$).

Characterization of Particulates Containing Naturally Occurring Radioactive Materials in Phosphate Processing Facility (인광석 취급 산업체에서 발생하는 천연방사성물질 함유 입자의 특성 평가)

  • Lim, HaYan;Choi, Won Chul;Kim, Kwang Pyo
    • Journal of Radiation Protection and Research
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    • v.39 no.1
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    • pp.7-13
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    • 2014
  • Phosphate rock, phosphogypsum, and products in phosphate processing facility contain naturally occurring radioactive materials (NORM). Therefore, they may give rise to enhanced radiation dose to workers due to inhalation of airborne particulates. Internal dose due to particle inhalation varies depending on particle properties. The objective of the present study was to characterize particle properties at the largest phosphate processing facility in Korea. A cascade impactor was employed to sample airborne particulates at various processing areas in the plant. The collected samples were used for characterization of particle size distribution, particle concentration in the air, and shape analysis. Aerodynamic diameters of airborne particulates ranged 0.03-100 ${\mu}m$ with the highest concentration at the particle size range of 4.7-5.8 ${\mu}m$ (geometric mean = 5.22 ${\mu}m$) or 5.8-9.0 ${\mu}m$ (geometric mean = 7.22 ${\mu}m$). Particle concentrations in the air varied widely by sampling area up to more than two orders of magnitude. The large variation resulted from the variability of mechanical operations and building ventilations. The airborne particulates appeared as spheroids or rough spherical fragments across all sampling areas and sampled size intervals. Average mass densities of phosphate rocks, phosphogypsums, and fertilizers were 3.1-3.4, 2.1-2.6, and 1.7 $gcm^{-3}$, respectively. Radioactivity concentration of uranium series in phosphate rocks varied with country of origin, ranging 94-866 $Bqkg^{-1}$. Among the uranium series, uranium was mostly concentrated on products, including phosphoric acid or fertilizers whereas radium was concentrated on byproducts or phosphogypsum. No significant radioactivity of $^{226}Ra$ and $^{228}Ra$ were found in fertilizer. However, $^{40}K$ concentration in fertilizer was up to 5,000 Bq $g^{-1}$. The database established in this study can be used for the accurate risk assessment of workers due to inhalation of airborne particles containing NORM. In addition, the findings can be used as a basic data for development of safety standard and guide and for practical radiation safety management at the facility.

Characteristics of posteroanterior cephalometric analysis in children with skeletal Class I malocclusion (성장기 골격성 I 급 부정교합 환자의 정모두부방사선 계측의 특징)

  • Moon, Yoon-Shik;Kim, Jung-Kook;Jung, Hyun-Sung;Sung, Sang-Jin
    • The korean journal of orthodontics
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    • v.31 no.2 s.85
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    • pp.159-172
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    • 2001
  • Three dimensional analysis of malocclusion and craniofacial deformation is essential for the successful orthodontic treatment. But the orthodontists are not familiar with diagnosis and treatment plane based on lateral cephalometric analysis. Since orthodontists do not posses a sufficient knowledge in standard value of posteroanterior cephalometric anaysis and of clinical importance for transverse jaw growth. In this study male(n=130) and female(n=171) aged from 6 to 16 and diagnosed as Class I malocclusion were selected to analysis width of cranium, maxilla and mandible on the posteroanterior cephalogram. The changes as a function of chronologic age and cervical vertebrae maturity index(CVXI) were examined. The Proper regression model was selected by sex with polynominal regression models and method of variable selection. Mean of each measurements and 70% confidence interval of individual measurement according to age was assesed and a graphs were made. Results are as follows :1. All the measurements for the width are gradually incresed as increase in chronologic age and CVMI. From the total amount of change between age 6 and 16, there is a tendency that mandibular width is broader than maxillary width and the width of male is broader than female. 2. There is no statistically significant sexual difference in Mx-Mn difference, Mx-Mn width differential, Mx/Mn ratio according to age and CVMI. 3. Mean of each measurement and 70% confidence interval of individual measurement according to age and sex were assessed and graphs were made for maxillary width, mandibular width, Mx-Mn difference, Mx/Mn ratio. 4. The width of maxilla and mandible in Korean children are broader than Western children during growth period.

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Comparative study in marginal fit of a pressed ceramic and feldspathic porcelain fused to metal restoration (열-가압을 이용한 금속 도재관과 전통적인 금속 도재관의 변연 적합도 비교 연구)

  • Kim, Yoon-Young;Park, Won-Hee;Yoo, Dong-Yeob;Lee, Young-Soo
    • The Journal of Korean Academy of Prosthodontics
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    • v.48 no.4
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    • pp.273-279
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    • 2010
  • Purpose: The purpose of this in vitro study was to compare the marginal adaptation of a ceramic-pressed-to-metal restoration with traditional metal-ceramic restoration. Materials and methods: Duplicating the prepared resin tooth, 20 metal dies were fabricated. Twenty metal copings of 2 groups which were metal ceramic restoration and pressed to metal restoration were fabricated. The marginal opening of each coping was measured with Microscope (BX 60M-36E $41D^{(R)}$: Olympus, Japan). After porcelain build-up, the marginal opening of metal ceramic restoration and pressed to metal restoration ($PoM^{(R)}$: Ivoclar vivadent., Liechtenstein) were also evaluated in the same method. The measurements were analyzed using Wilcoxon Signed Ranks test and Mann-Whitney U test. Results: Within the limits of this study, the results were as follows. 1. Metal-ceramic restorations in coping state ($64.93{\pm}12.48\;{\mu}m$) in compared with Metal ceramic restorations after porcelain build-up ($63.43{\pm}12.86\;{\mu}m$) had no significant difference in marginal adaptation. 2. Pressed-metal-ceramic restorations in coping state ($50.00{\pm}12.28\;{\mu}m$) in compared with Pressed metal ceramic restorations after porcelain build-up ($56.72{\pm}13.80\;{\mu}m$) had no significant difference in marginal adaptation. 3. Metal-ceramic restorations in compared Pressed-metal-ceramic restorations had no significant difference in marginal adaptation. Conclusion: Pressed-metal-ceramic restorations have the advantage of being technically less change through using of the lost-wax technique and this allows for the convenience of a full-contour ceramic wax-up as opposed to the more technique-sensitive layering method. Pressed-metal-ceramic restorations may be considered in clinic on the basis of the result of this study and the advantage of this system.