• Title/Summary/Keyword: plaster

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A Study on the Engineering Characteristics of the plaster-soil uiiitures (석고플라스터 혼합토의 공학적 특성)

  • 도덕현;정성모
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.27 no.4
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    • pp.53-60
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    • 1985
  • The plaster mixed to loam and sandy soil from 4 to 12 percent by dry soil weight, and the compaction, permeability, CBR, unconfined compressive strength and freezingthawing test were performed The results obtained are summarized as follows; 1.The coefficient of permeability reduced sharply at the plaster content of 4 percent, and in the CBR test, the swelling ratio reduced by the increment of plaster content. 2.The addition of plaster increased the unconfined compressive strength by the cementing effect, and it was found that the optimum plaster content, existed with the soil type, which showed the maximum strength 3.It was possible to enhance the unconfined compressive strength of the gypsum-lime-soil mixtures when the optimum content of plaster was mixed to the hydrated lime. 4.In case of sandy soil, the relative frost heave decreased with the mixture of plaster, however in loam soil, the relative frost heave began to increase at the plaster content of 12 percent than non-treated soil. Therefore the optimum plaster content existed for protecting frost heave by the different soil type. 5.The above summarized results make it possible to expect the effects such as improvement of soil properties, decrement of permeability, increment of unconfined compressive strength, and protection of frost heave, etc, therefore, it is considered that it is possible to it is plaster as sub-base materials of road.

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Influence of special plaster on the out-of-plane behavior of masonry walls

  • Donduren, Mahmut Sami;Kanit, Recep;Kalkan, Ilker;Gencel, Osman
    • Earthquakes and Structures
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    • v.10 no.4
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    • pp.769-788
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    • 2016
  • The present study aimed at investigating the effect of a special plaster on the out-of-plane behavior of masonry walls. A reference specimen, plastered with conventional plaster, and a specimen plastered with a special plastered were tested under reversed cyclic lateral loading. The specimens were identical in dimensions and material properties. The special plaster contained an additive, which increased the adherence strength of the plaster to the wall. The amount of the additive in the mortar was adjusted based on the preliminary material tests. The influence of the plaster on the wall behavior was evaluated according to the initial cracking load, type of failure, energy absorption capacity (modulus of toughness), and crack pattern of the wall. Despite having limited contribution to the ductility, the special plaster increased the ultimate load capacity of the wall about 25%. The failure mode of the wall with special plaster resembled the plastic failure mechanism of a reinforced concrete slab in the formation of yielding lines along the wall. The deflection at failure and the modulus of toughness of the wall with special plaster were measured to be in order of 60% and 75% of the corresponding values of the reference wall.

Development of the Simulated Die Casting Process by using Rapid Prototyping (쾌속 조형 공정을 이용한 다이캐스팅 제품의 시작 공정 개발)

  • Kim K. D.;Yang D. Y.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2002.02a
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    • pp.180-186
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    • 2002
  • The simulated die-casting process in which the traditional plaster casting process is combined with Rapid Prototyping technology is being used to produce Al, Mg, and Zn die-casting prototypes. Unlike in the die-casting process, molten metal in the conventional plaster casting process is fed via a gravity pour into a mold and the mold does not cool as quickly as a die-casting mold. The plaster castings have much larger and grosser grain structure as compared as the die-castings and the thin walls of the plaster mold cavity may not be completely fillet Because of lower mechanical properties induced by the large grain structure and incomplete Idling, the conventional plaster casting process is not suitable for the trial die-casting Process. In this work, an enhanced trial die-casting process has been developed in which molten metal in the plaster mold cavity is vibrated and pressurized simultaneously. Patterns for the casting are made by Rapid Prototyping technologies and then plaster molds, which have runner system, are made using these patterns. Imparted pressurized vibration to molten metal has made grain structure of castings much finer and improved fluidity of the molten metal enough to obtain complete filling at thin walls which can not be filled in the conventional plaster casting process.

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A Bundled Educational Solution to Reduce Incorrect Plaster Splints Applied on Patients Discharged from Emergency Department

  • Chia Wei Jennifer Ting;Shu Fang Ho;Fatimah Lateef
    • Quality Improvement in Health Care
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    • v.29 no.2
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    • pp.64-84
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    • 2023
  • Purpose:Plaster splints are routinely performed in the Emergency Department (ED) and avoidable complications such as skin ulcerations and fracture instability arise mainly due to improper techniques. Despite its frequent use, there is often no formal training on the fundamental principles of plaster splint application for a medical officer rotating through ED. We aim to use Quality Improvement (QI) methodology to reduce number of incorrect plaster splint application to improve overall patient care via a bundled educational solution. Methods: We initiated a QI program implementing concepts derived from the Institute for Healthcare Improvement models, including Plan-Do-Study-Act (PDSA) cycles, to decrease the rate of incorrect plaster splint application. A bundled education solution consisting of three sequential interventions (practical teaching session, online video lecture and quick reference cards) were formulated to specifically target critical factors that had been identified as the cause of incorrect plaster splints in ED. Results: With the QI intervention, our overall rate of incorrect plaster splints was reduced from 84.1% to 68.6% over a 6-month period. Conclusion: Following the QI project implementation of the bundled educational solution, there has been a sustained reduction in incorrect plaster splints application. The continuation of the training program also ensures the sustainability of our efforts in ED.

A Study on the Existence of Lime Plaster Wall in the Joseon Dynasty, Based on the Analysis of Construction Reports of 'Sanleong-Uigwe' & 'Yeonggeon-Uigwe' - Emphasized on the Government Building Constructions - (산릉.영건의궤 분석을 통한 조선시대 건축에서 회벽의 존재 여부 고찰 -조선 후기 관영건축을 중심으로-)

  • Lee, Kweon-Yeong
    • Journal of architectural history
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    • v.19 no.3
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    • pp.89-106
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    • 2010
  • Since the 1970's, UNESCO and ICOMOS have adopted or emphasized on the principles of historic preservation. One of them is what to require a repair should not be repaired beyond the limits of the features and techniques which had been adopted in those days of establishment. On the premise, this paper is to examine the materials and technique of wall plaster work in the government building constructions in the Joseon dynasty. The result of this examination shall come up with a basic conformity in the case of repairing the building established in the late of Joseon dynasty. This paper is carried out for the proper repair and restoration of architectural cultural properties. Construction reports and other documents in those days are examined for the study. Following conclusions have been reached through the study. The materials and technique which applied to wall plaster work in those days were quite different from the present. The technique that was used to wall plaster of government buildings in those days was not a lime wall plaster, but sand coat one. The kinds of material for setting of the sand coat wall plaster had been revised with the change of the times or constructions. The main kinds of material were composed of sand, white clay, paper fiber, and cereal starch. However, the present materials were composed of sand, white clay. Therefore, the present materials and technique which applied to wall plaster work for the repair and restoration of architectural cultural properties have to be revised and corrected.

The Effect of Aloe, Gelfoam, Plaster on Bone Formation in Applying to the Bone Defect (Aloe, Gelfoam, Plaster가 골결손부의 신생골 형성에 미치는 영향에 관한 실험적 연구)

  • Choi Eui-Hwan;Kim Su-Gwan
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.29 no.2
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    • pp.493-505
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    • 1999
  • Purpose: This study was to evaluate the effects of Aloe. Gelfoam. and Plaster of Paris on bone healing. Materials and Methods: Four experimental defects were created for placement of the three materials in the right femur of dogs. One defect served as an empty control site. The evaluation was performed at 1-. 6-. and 12-weeks by light microscopy and radiographs. Results: Radiographic and histologic examinations showed new bone formation in the presence of Aloe, Gelfoam. and Plaster of Paris and similar bone healing reactions. Conclusion: On the basis of these findings, it was concluded that Aloe, Gelfoam. and Plaster of Paris may be adequate agents for use in bone procurement.

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Die Cast Prototyping using Plaster Casting with Pressurized Vibration Casting Machine

  • Kim, Ki-Don;Yang, Dong-Yol;Park, Tae-Kwon
    • International Journal of Precision Engineering and Manufacturing
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    • v.2 no.1
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    • pp.56-61
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    • 2001
  • This work is concerned with the development of a new plaster die casting process the combines pressurization and vibration for the prototyping of die-castings, and also with a plaster die-casting machine that has a structure quite similar to that of an ordinary die casting machine. The machine utilized an air cylinder for pressurization and a magnetic actuator for vibration. A rapid prototyped pattern is made by the LOM process to prepare a plaster mold. In the process, a plunger int he developed machine simultaneously pressurizes and vibrates the molten metal to fill the plaster mold completely and to facilitate the creation of nuclei in the molten metal, respectively. The developed machine produced a prototype of an end clutch cover with a remarkable improvement in mechanical properties.

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Design and Development of the Simulated Die casting Process by using Rapid Prototyping (쾌속조형을 이용한 다이 캐스팅 제품의 시작 공정 설계 및 제작)

  • Kim, Ki-Don;Yang, Dong-Yol;Jeong, Jun-Ho;Park, Tae-Kwon
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.7
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    • pp.167-173
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    • 2001
  • The simulated die-casting process in which the traditional plaster casting process is combined with Rapid Prototyping technology is being used to produce AI, Mg, and Zn die-casting prototypes. Unlike in the die-casting process, molten metal in the conventional plaster casting process is fed via a gravity pour into a mold and the mold does not cool as quickly as a die-casting mold. The plaster castings have much larger and grosser grain structure as compared with the normal die-castings and the thin walls of the plaster mold cavity may not be completely filled. Because of lower mechanical properties induced by the large grain structure and incomplete filling, the conventional plaster casting process is not suitable for the trial die-casting process to obtain quality prototypes. In this work, an enhanced trial die-casting process has been developed in which molten metal in the plaster mold cavity is vibrated and pressurized simultaneously. Patterns for the casting are made by Rapid Prototyping technologies and then plaster molds, which have a runner system, are made using these patterns. Pressurized vibration to imparted molten metal has made grain structure of castings much finer and improved fluidity of the molten enough to obtain complete filling at thin walls which may not be filled in the conventional plaster casting process..

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Formulation and Evaluation of Loxoprofen Plasters (록소프로펜 플라스터의 제제설계 및 평가)

  • 김태성;전인구
    • Biomolecules & Therapeutics
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    • v.9 no.4
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    • pp.298-306
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    • 2001
  • To develop a novel transdermal delivery system of loxoprofen (LP), a potent antiinflammatory and analgesic agent, the effects of vehicle composition and drug loading dose on the skin permeation property were investigated. And in vivo skin absorption property studied by analysing the $C_{max}$ and AUC was investigated after applying the developed plaster systems on rabbit back skin. Addition of isopropyl myristate (IPM) and IPM-diethylene glycol monoethyl ether (DGME) cosolvent in the plaster showed higher permeation rates than those from propylene glycol laurate-DGME cosolvent systems. As the concentration of LP in the plaster increased from 0.56 mg/$\textrm{cm}^2$ to 1.19 mg/$\textrm{cm}^2$, the drug release and skin permeation rates increased linearly. At loading dose of 1.19 mg/$\textrm{cm}^2$, the flux reached 35.6 $\mu$g/$\textrm{cm}^2$/hr. New LP plasters showed a good adhesive property onto skin, and showed no crystal formation. The AU $C_{0-24hr}$ and $C_{max}$ after dermal application of LP plaster (60 mg/70 $\textrm{cm}^2$) were found to be 6951$\pm$230 ng.hr/ml and 400$\pm$44 ng/ml, respectively. And the plasma concentration maintained above 300 ng/ml up to 24 hr period. In the carrageenan-induced rat paw edema test, LP plaster showed similar inhibition rate with marketed ketoprofen (Ketoto $p^{R}$) plaster.aster.r.

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A fundamental Study on the Performance Improvement of Hwangto plaster (황토미장재 성능개선을 위한 실험적 연구)

  • Hwang, Hey-zoo;Lee, Jong-kuk;Kang, Nam-yi
    • KIEAE Journal
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    • v.5 no.3
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    • pp.49-56
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    • 2005
  • Recently the Volatile Organic Compound, HCHO, a harmful object spout from the construction materials is made an issue of social problem. Also the appearance of the building where the confidentiality is high was interior air pollution and it was brought about a huge problem. The government research facility and a relation industry sector conducts a many effort to improves like this actual condition. The Diverse ability building material which contains the natural material of the jade, the charcoal and the hwangto instead of the finish material which contains the harmful chemical material, is becoming development and utility. Hereupon the study have carried out research on hwangto plaster that was composed of hwangto and rice straw. The result of test that is deduced by basic proportion is properly appeared with suitable ratio of the hwangto and the sand to 4:6~5:5 by the compressive strength and crack control, workability. The result of test, that adds the rice straw to basic blending for a crack control, appeared with the fact that it is most suitable 3%to add the rice straw that has a length of 0.5cm~2cm. The result of test that plaster over the large size to compare a cement plaster with a hwangto plaster show a similar efficiency by workability. Also it controlled the crack and peeling off actual condition which is discovered from the hwangto plaster of existing perfectly.