• Title/Summary/Keyword: sacrifice layer

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A Evaluation of Corrosion Resistance on the Thermal Sprayed Coating Tube and Cladded Tube of the Open Rack Vaporizer (용사코팅튜브와 클래드튜브 기화기에 대한 내식성 평가)

  • Baek Jong-Hyun;Lee Jae-Ho;Kim Yong-Seog;Shin Dong-Hyuck;Kim Woo-Sik
    • Journal of the Korean Institute of Gas
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    • v.2 no.4
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    • pp.67-72
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    • 1998
  • Due to excellent corrosion resistance, in particular against sea water, Al-2wt.$\%$Zn alloys have been used as the sacrifice anode material for tube of the ORV. Al-2wt.$\%$Zn alloys thermal-sprayed coating, however, were spalled on the lower part of ORV due to the lack of bonding strength between base material and coating layer and the dropping energy of sea water, To overcome the problems of the thermal spray coating, we developed the cladded tube manufacturing process by coextrusion of the clad and base metal. The corrosion resistance of cladded tube was improved by two times at least, compared with that of the present thermal spray coated vaporizer tubes.

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THE ONSET OF ANKYLOSIS FOLLOWING INTRUSIVE LUXATION INJURIES (외상성 intrusion 치아의 교정적 견인시기에 관한 실험적 연구)

  • Chung, Kyu-Rhim;Turley, Patrick-K.
    • The korean journal of orthodontics
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    • v.21 no.2 s.34
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    • pp.259-272
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    • 1991
  • Orthodontic traction has been suggested as the treatment of choice for intrusive luxation injuries. Prior research has shown orthodontic forces to be ineffective in the presence of ankylosis or in cases with zero mobility following the injury. If orthodontic traction is to be effective, it must be initiated prior to the onset of ankylosis. The purpose of this study was to describe the effects of intrusive luxation at various times following the injury, and to determine the time of the onset of ankylosis, and to examine what effect immediate partial luxation has on the onset of ankylosis. Eight young mongrel dogs were utilized for this study. Intrusive luxation was produced with an axial impact using a gravity hammer and a specially designed holding device on 4 teeth (2 max. and 2 man. first premolars) in each dog. The teeth were intruded approximately 3-4mm in an axial direction. One maxillary and one mandibular premolars were partially luxated with the other two teeth being untouched. Pre and posttrauma tooth position was documented with plaster models and radiographs taken with an individualized X-ray jig. Dogs were sacrificed immediately following the injury and at 1, 2, 4, 7, 10, 14 and 21 days respectively. Tetracycline was administered as a vital bone marker 24 hours before sacrifice. Block sections of the tooth and alveolus were prepared for decalcified and non decalcified histologic sections. The effects of traumatic intrusion were analyzed by means of model casts, radiographs, tetracycline bone marking and histologic preparations. The results obtained were as follows: 1. The animal sacrificed immediately following the injury displayed alveolar fractures, torn periodontal ligaments, and areas of direct tooth-bone contact. 2. The odontoblastic layer of the pulp was disorganized as early as 24 hours after the injury. 3. Bony remodeling was noted at 4 days along with active surface resorption. 4. Ankylosis was first seen 7 days after the injury. 5. Osteogenesis in the dentin (thick tetracycline bands) was observed 7 days after the injury. 6. There was no progressive root resorption and ankylosis where the periodontal ligament has been healed. 7. The Luxated group showed significantly more root resolution and ankylosis than the Nonluxated group with increased observation periods. The results suggest that ankylosis may occur within the first week following the injury, and hence orthodontic traction should be initiated as soon after the injury as possible.

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Characteristics of SiO2/Si Quantum Dots Super Lattice Structure Prepared by Magnetron Co-Sputtering Method (마그네트론 코스퍼터링법으로 형성한 SiO2/Si 양자점 초격자 구조의 특성)

  • Park, Young-Bin;Kim, Shin-Ho;Ha, Rin;Lee, Hyun-Ju;Lee, Jung-Chul;Bae, Jong-Seong;Kim, Yang-Do
    • Korean Journal of Materials Research
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    • v.20 no.11
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    • pp.586-591
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    • 2010
  • Solar cells have been more intensely studied as part of the effort to find alternatives to fossil fuels as power sources. The progression of the first two generations of solar cells has seen a sacrifice of higher efficiency for more economic use of materials. The use of a single junction makes both these types of cells lose power in two major ways: by the non-absorption of incident light of energy below the band gap; and by the dissipation by heat loss of light energy in excess of the band gap. Therefore, multi junction solar cells have been proposed as a solution to this problem. However, the $1^{st}$ and $2^{nd}$ generation solar cells have efficiency limits because a photon makes just one electron-hole pair. Fabrication of all-silicon tandem cells using an Si quantum dot superlattice structure (QD SLS) is one possible suggestion. In this study, an $SiO_x$ matrix system was investigated and analyzed for potential use as an all-silicon multi-junction solar cell. Si quantum dots with a super lattice structure (Si QD SLS) were prepared by alternating deposition of Si rich oxide (SRO; $SiO_x$ (x = 0.8, 1.12)) and $SiO_2$ layers using RF magnetron co-sputtering and subsequent annealing at temperatures between 800 and $1,100^{\circ}C$ under nitrogen ambient. Annealing temperatures and times affected the formation of Si QDs in the SRO film. Fourier transform infrared spectroscopy (FTIR) spectra and x-ray photoelectron spectroscopy (XPS) revealed that nanocrystalline Si QDs started to precipitate after annealing at $1,100^{\circ}C$ for one hour. Transmission electron microscopy (TEM) images clearly showed SRO/$SiO_2$ SLS and Si QDs formation in each 4, 6, and 8 nm SRO layer after annealing at $1,100^{\circ}C$ for two hours. The systematic investigation of precipitation behavior of Si QDs in $SiO_2$ matrices is presented.

A Study on Skin - From the Perspective of Analytical Psychology - (피부 - 분석심리학적 조명 -)

  • Young Sun Pahk
    • Sim-seong Yeon-gu
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    • v.29 no.2
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    • pp.127-156
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    • 2014
  • This thesis is an psychological study investigating the meanings of skin from the perspective of analytical psychology. Skin, as the outermost layer of our body, protects the body and carries out essential physiologic functions. It is an organ of the body and also psychological contents can be expressed on it in various forms. We can find sociocultural connotations of skin, some of which are demonstrated in our language. Skin may become a carrier of persona which defines a person's role in the society. And it can be a place where ego is expressed. Eros is the principle of relationship by Jung's definition and skin is the space where eros is realized intensely. Skin may carry meanings as a symbol of transformation. Skin disease can be interpreted as a message from Self in certain cases. The theme of casting off skin in myths and dreams can be an analogy of an individual's sacrifice for individuation, and putting on a skin may imply taking special properties in psychological level.

A Study on Marketing of Cultured Laver Products (양식해태의 유통에 관한 조사 연구)

  • 유충열
    • The Journal of Fisheries Business Administration
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    • v.4 no.1_2
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    • pp.19-57
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    • 1973
  • Laver io one of the most necessary and seasonal items in Korean food from oldtimes. Laver is lagely eaten in dried form, and its supply depends entirely upon culture weeds. The history of laver culture in Korea about sixty or seventy years is older than in Japan. Significance of laver culture is divided into two aspects, one is food supply in the nation, and the other is export to other countries. Houses engaged in laver culture are about foully thousands, and laver production in 1972 is estimated as 1, 3 bitten sheets. (1 sheet is a dried laver of 20 cm sq, in the shape of paper) Especcially meaning of layer production is the concentration of labour input, and systematic management of labour. From around 1920, the method of laver culture was introduced by Japanese Imperialism for mono culture in shallow seas, and mass products of laver is provided to Japan market, DOMESTIC MARKET Fundamental consume function calculates at below, $D_{(68_71)}$=16354 $Y^{0.471}$ $P^{-1.0662}$ where D is total layer demand, Y income variable, P price variable. It means income elasticity is 476. in the whole country, and price elasticity is 1, 07. But generally income elasticity is higher in urban area than in rural area, as shown at 1, 3 in Seoul city. Expence of laver in house expenditure is mutually correlated with another expence, See Table 12 about the relative function. See Table 14 and 16 about the relation between the gathering and the changes of price in auction, wholesale and retail price support system is for two effects, one of which is constraint of the upper price, the other is rise of the lower price. Before the system control, the equation in three year average calculated as below, $Y_{b}$ =18, 907.7455+15435.9364 t (r=0.89) where the origin t=0 is the November and the units are month. Post the system control, $Y_{p}$ =30, 047.9636+1, 631.1721t (r=0.97) therefore, this system has an effect only on the rise of lower price, Average annual margins of laver products at four market levels according to the consumer spent is below. EXPORTING MARKET Japanese demand function of laver products is, Log D=5, 289+1, 108 Log Y-1, 395 Log P (r=0.987) where D is Japanese laver demand, Y income variable, P price variable. according to which income elasticity is 1. 1 and price elasticity is 1.4. Laver production in 1970 tile highest record till then, is estimated as six billion sheets. But the recent improvement of laver culture techniques, the production of seeds and freezing storage of seeds has been stabilized. Futher new culture farms have been developed by means of break- water fences or by floating culture method. These improvements have been backed up with increased demand of laver products. Import quantity and price of Korean laver products are restrained by three organizations, that is producer, distributor and consumer. This relationship calculated by regression equation shows that import is influenced only producer organization, at the sacrifice of consumer profit. For increase to export of laver products, we urgently require to open foreign trade of laver products for Japanese consumer, .and Japan has political responsibility to solve Korean laver structure. But with long run timeseries, as regards Japanese production and import quantity, importing function shows increasing trend as below, 250 million sheets <3, 947.1674+0.005 $L_{g}$ >) 600 million sheets where $L_{q}$ is relative production quantity of laver in Japan. (unit; 100 thousand sheets) Our Export effort should be put on the highly processed products whithin the restraind quote.ote.

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THE EFFECTS OF DIETARY CONSISTENCY ON THE TRABECULAR BONE ARCHITECTURE IN GROWING MOUSE MANDIBULAR CONDYLE : A STUDY USING MICRO-CONFUTED TOMOGRAPHY (성장 중인 쥐에서 음식물의 경도가 하악 과두의 해면골에 미치는 영향 : 미세전산화 단층촬영을 이용한 연구)

  • Youn, Seok-Hee;Lee, Sang-Dae;Kim, Jung-Wook;Lee, Sang-Hoon;Hahn, Se-Hyun;Kim, Chong-Chul
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.2
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    • pp.228-235
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    • 2004
  • The development and proliferation of the mandibular condyle can be altered by changes in the biomechanical environment of the temporomandibular joint. The biomechanical loads were varied by feeding diets of different consistencies. The purpose of the present study was to determine whether changes of masticatory forces by feeding a soft diet can alter the trabecular bone morphology of the growing mouse mandibular condyle, by means of micro-computed tomography. Thirty-six female, 21 days old, C57BL/6 mice were randomly divided into two groups. Mice in the hard-diet control group were fed standard hard rodent pellets for 8 weeks. The soft-diet group mice were given soft ground diets for 8 weeks and their lower incisors were shortened by cutting with a wire cutter twice a week to reduce incision. After 8 weeks all animals were killed after they were weighed. Following sacrifice, the right mandibular condyle was removed. High spatial resolution tomography was done with a Skyscan Micro-CT 1072. Cross-sections were scanned and three-dimensional images were reconstructed from 2D sections. Morphometric and nonmetric parameters such as bone volume(BV), bone surface(BS), total volume(TV), bone volume fraction(BV/TV), surface to volume ratio(BS/BV), trabecular thickness(Tb. Th.), structure model index(SMI) and degree of anisotropy(DA) were directly determined by means of the software package at the micro-CT system. From directly determined indices the trabecular number(Tb. N.) and trabecular separation(Tb. Sp.) were calculated according to parallel plate model of Parfitt et al.. After micro-tomographic imaging, the samples were decalcified, dehydrated, embedded and sectioned for histological observation. The results were as follow: 1. The bone volume fraction, trabecular thickness(Tb. Th.) and trabecular number(Tb. N.) were significantly decreased in the soft-diet group compared with that of the control group (p<0.05). 2. The trabecular separation(Tb. Sp.) was significantly increased in the soft-diet group(p<0.05). 3. There was no significant differences in the surface to volume ratio(BS/BV), structure model index(SMI) and degree of anisotropy(DA) between the soft-diet group and hard-diet control group (p>0.05). 4. Histological sections showed that the thickness of the proliferative layer and total cartilage thickness were significantly reduced in the soft-diet group.

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