• Title/Summary/Keyword: rapid consolidation

Search Result 71, Processing Time 0.029 seconds

A Study on the Tensile Strength of Glass Woven Fiber Reinforced PET Composites (직조유리섬유강화 PET수지 복합체의 인장특성에 관한 연구)

  • 김홍건;최창용
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.12 no.1
    • /
    • pp.45-49
    • /
    • 2003
  • Tensile strength of the woven glass fiber reinforced PET (Poly-Ethylene-Terephthalate) matrix composite manufactured by rapid press consolidation technique was investigated and evaluated. During pre-heating, consolidation and solidification stages, the optimal manufacturing conditions for this composite were discussed based on the void content and tensile properties depending on vacuum condition. It is found that the effect of vacuum condition during preheating gives a substantial difference on the strength as well as microstructure. It is also found that the failure micromechanism shows several energy absorption processes enhancing fracture toughness.

SONOGRAPHIC CHANGE OF MANDIBULAR DISTRACTION OSTEOGENESIS (하악골 신장술의 초음파적 변화)

  • Kim, Chul-Hwan
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
    • /
    • v.33 no.4
    • /
    • pp.297-306
    • /
    • 2007
  • Distraction osteogenesis was pioneered by Ilizarov in the treatment of injured extremities. Its subsequent application to Oral and Maxillofacial Surgery has opened a new chapter in the treatment of facial deformity. Careful monitoring of the period of distraction and consolidation of the callus is important and has been well described. Complications, such as infection, haematoma and premature ossification, are difficult to diagnose and can compromise the outcome after the surgery. Too slow rate of distraction results in premature fusion of cortices and too rapid information of bone 'cyst' within the callus distraction. I experienced 2 patients of congenital unilateral mandibular hypoplasia, so called Hemifacial Microsomia. After distraction surgery, I evaluated callus formation of mandibular distraction with Ultrasound Sonography during distraction and consolidation period. Plain radiography, although it enables accurate measurement of the distraction gap, did not give sufficient detail to allow assessment of early stages of bone formation, But, ultrasound monitoring could enable continuous monitoring of the distraction gap without exposure to ionizing radiation and allow detection of fine detail, which may influence manipulation of the callus.

Processing of $Si_3N_4/SiC$ and Boron-Modified Nanocomposites Via Ceramic Precursor Route

  • Lee, Hyung-Bock;Rajiv S. Mishra;Matt J. Gasch;Han, Young-Hwan;Amiya K. Mukherjee
    • The Korean Journal of Ceramics
    • /
    • v.6 no.3
    • /
    • pp.245-249
    • /
    • 2000
  • Consolidation of amorphous powders is emerging as a route for synthesis of high strength composite materials. Diffusion processes necessary for consolidation are expected to be more rapid in amorphous state(SRO) than in the crystalline state(LRO). A new synthesis technique of exploiting polymeric ceramic precursors(polysilazane and polyborosilazane) is derived for Si$_3$N$_4$/SiC and boron-modified nanocomposites for extremely high temperature applications up to 200$0^{\circ}C$. The characterization methods include thermal analysis of DTA, and XRD, NMR, TEM, after pyrolysis, as a function of time and temperature.

  • PDF

Rapid estimation of salinity in seawater intrusion zones and correlation analysis between resistivity and salinity (해수침투 지역의 염분농도 분포 파악 및 전기비저항의 상관성분석 사례)

  • Jung, Lae-Chul;Kim, Jung-Ho;Kim, Ki-Seog;Kim, Jong-Hoon;Ahn, Hee-Yoon
    • 한국지구물리탐사학회:학술대회논문집
    • /
    • 2007.06a
    • /
    • pp.307-312
    • /
    • 2007
  • Seawater intrusion in estuarine regions is an important issue in protecting groundwater against salinity increase as well as in protecting construction materials against corrosion. For example, drain water ejected during accelerated consolidation for the improvement of soft ground can cause damages to farm land because the drain water from seawater intrusion zones contains salinity. In this study, we have employed correlation analysis between resistivity value and salinity of in situ pore water. The correlation analysis indicates that resistivity and salinity are in exponential relationship with good correlation. Therefore we suggest that rapid estimation of spatial distribution of NaCl is possible using resistivity data.

  • PDF

Compressibility Characteristics of the Lime Treated Clay (생석회 혼합토의 압축특성에 관한 연구)

  • 민덕기;황광모;오미희
    • Journal of the Korean Geotechnical Society
    • /
    • v.19 no.6
    • /
    • pp.23-29
    • /
    • 2003
  • In this paper, effects of the acidification of ground and the chemical additive materials-ferric oxide, calcium chloride and calcium sulphate on the compressibility characteristics of the marine clay treated with quick lime were investigated. The rapid inflection point method was carried out. Results showed that the compression index of the untreated marine clay increased as the pH of pore water decreased. Also, the preconsolidation pressure, the coefficient of consolidation and the coefficient of permeability of the untreated marine clay decreased with pH of pore water. In the case of the marine clay treated with the quick lime-calcium chloride, the compression index decreased and the coefficient of consolidation and the coefficient of permeability increased. Specially, the preconsolidation pressure of sample treated with the quick lime-ferric oxide was higher than that of another samples.

Chronic Progressive Pneumonic Consolidation with Cavity (공동을 동반한 만성 진행성 폐렴양 병변)

  • Kwon, Seon-Og;Kim, Hyung-Jung;Ahn, Chul-Min;Kim, Sung-Kyu;Lee, Won-Young;Kim, Sang-Jin;Lee, Ki-Bum
    • Tuberculosis and Respiratory Diseases
    • /
    • v.38 no.4
    • /
    • pp.401-405
    • /
    • 1991
  • Bronchioloalveolar cell carcinoma accounts for less than 6% of all primary lung cancer but has distinct clinical and radiological features and unusual pathologic appearance. The characteristic features are its peripheral location and tendency of rapid progression to diffuse type via aeroginous and lymphatic route without surgical intervention. Among them, mucin secretory type bronchioloalveolar cell carcinoma is the rarest and most distinctive. We experienced a case of mucin secretory type bronchioloalveolar cell carcinoma in a 47 year old female with roentgenographic findings of chronic progressive pulmonary consolidation with muliple cavities.

  • PDF

Conservation of artifacts excavated from Imdang, Kyǒngsan Province-Metals and Lacquerware (경산시 임당유적 출토 유물 보존처리-금속 및 칠기유물을 중심으로)

  • Yu, Jae-Eun;Shin, Ui-Kyoung;Hwang, Jin-Ju;Goh, Dong-Ha
    • 보존과학연구
    • /
    • s.19
    • /
    • pp.109-132
    • /
    • 1998
  • According to excavation of Imdang site, these sites were excavated place to a various of sites from Early lron period to the Koryo Kingdom. Artifacts to be conserved were excavated from A, D and E district. Metal artifacts were excavated from D and E district and lacquer ware artifacts were excavated from Adistrict. Metal artifacts including lacquer ware iron sword, imitative bronze mirror, Osujen and bronze artifact with letter and so on. Bronze artifacts were covered with soil and rust and performed consolidation after passivation treatment with Benzotriazole solution. Also, iron artifacts performed desalting treatment with 0.1M sesquicarbonate solution. After desalinization, adhesive of these artifacts were processed with Araldite(rapid type) after consolidation with20%∼30% NAD-10 solution. Lacquer ware artifacts remained fragments of lacquer to be all corroded and soiled. Therefore these artifacts retained its original form. Fragments of lacquer joined with Caparol 1%∼3% solution and the soil of relics coated with PSNY 3%∼6% solution. There were many kinds of lacquer were. Lacquer ware artifacts presumed to a string instrument that provide important clues for lacquer ware research. As for lacquer fragments inquire, paints grain size were $2∼5\mum$ and conformed to vanished three times.

  • PDF

The Effect of Rapid Consolidation of Nanostructured MoSi2-SiC Composite on its Mechanical Properties (나노구조 몰리브덴늄실리사이드-실리콘카바이드 복합재료의 급속소결과 기계적 성질)

  • Ko, In-Yong;Chae, Seung-Myoung;Shon, In-Jin
    • Korean Journal of Metals and Materials
    • /
    • v.48 no.5
    • /
    • pp.417-423
    • /
    • 2010
  • A dense nanostructured MoSi$_{2}$-SiC composite was synthesized by a pulsed current activated combustion synthesis method within 2 min of one step from mechanically activated powders of Mo$_{2}$C and Si. Simultaneous combustion synthesis and consolidation were accomplished under the combined effects of a pulsed current and mechanical pressure. Highly dense MoSi$_{2}$-SiC with a relative density of up to 98% was produced under simultaneous application of an 80 MPa pressure and pulsed current. The average grain size and mechanical properties of the composite were investigated.

Interpreting Characteristics of Educational Facilities Arrangement According to Jinhae's Historical Development Using Space Syntax Theory (진해 교육시설의 시대별 배치 특징에 관한 공간통사론적 해석)

  • Yang, Seung-Jung;Lee, Hyun-Hee;Lee, Jae Hong
    • Journal of the Korean Institute of Educational Facilities
    • /
    • v.22 no.3
    • /
    • pp.21-29
    • /
    • 2015
  • Jinhae's educational facilities had been located in the most integrated area at the beginning. As Jinhae's spatial layout has been in a rapid growth by constructing new towns and experiencing major consolidations over years, it was argued that this morphological transformation inevitably brought to the change of the characteristics of educational facilities' arrangement. In this reason, a number of studies have discussed the ways of how they have been settled down from the beginning of Jinhae. However, they did not take into an account of both the first consolidation happened in 1985 and the second one in 2013. This paper therefore aims to investigate how Jinhae's urban structure has been transformed between the two consolidations from a syntactical perspective, and then to interpret characteristics of educational facilities arrangement accordingly. This study finds out that when Jinhae experienced the first consolidation, educational facilities were occupied in highly segregated areas in terms of both global and local integration values. However, their locations turned out to be more intelligible after the second consolidation. This suggests that they have a significant effect on the process of urban growth at local level. Although the educational facilities particularly in Pungho and Ungchun are in highly integrated spaces at global level, they are still less intelligible.

Application of Geophysical Techniques for Observing the Void Ratio Changes of Dredged Soils (준설토의 간극비 변화 관찰을 위한 물리탐사기법의 적용)

  • Hong, Young-Ho;Lee, Jong-Sub;Lee, Changho
    • Journal of the Korean Geotechnical Society
    • /
    • v.30 no.9
    • /
    • pp.19-28
    • /
    • 2014
  • It is necessary to understand the behavior of the soils for the dredging constructions. The objective of this study is to estimate void ratio and density changes of the dredged soils by using the geophysical testing methods. A series of laboratory tests is performed to obtain geotechnical index properties of the specimen, retrieved from the west coastal of Korea. The sedimentation and self-weight consolidation tests are carried out with observing changes of the interfacial height and the elastic wave velocities. The same amounts of the soils are poured into the testing column at intervals of 12 hours until the interheight reaches to a certain level. After the completion of the sedimentatation and self-weight consolidation tests, downward permeability test is performed to assess a tidal influence in the nearshore. The mini resistance cone is penetrated into the specimen to measure the electrical resistivity with depth. All tests are completely finished, the weight of specimens are measured to calculate the void ratio with the depth. Experimental results show that the aspects of the self-weight consolidation are invisible during dredging process because of rapid sedimentation characteristics of ML. However, the elastic wave velocities increase with increasing in the effective stresses. During permeability test, measured permeability and the elastic wave velocities maintain almost identical values. Void ratio based on the elastic wave velocities changes linearly with time during the step dumpings. Void ratio estimated by the electrical resistivity represents the repeatedly layered depositions according to the step-by-step dumpings. Void ratio determined by soil sampling is similar to those of elastic waves and electrical resistivity profiles. This experimental study demonstrates that the geophysical testing methods may be an effective method for evaluating the behavior of dredged soils.