• Title/Summary/Keyword: material area

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Decrease in the Particle Size of Paclitaxel by Increased Surface Area Fractional Precipitation (표면적이 증가된 분별침전에 의한 paclitaxel의 입자 크기 감소)

  • Lee, Ji-Yeon;Kim, Jin-Hyun
    • Microbiology and Biotechnology Letters
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    • v.40 no.2
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    • pp.157-162
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    • 2012
  • In this study, we have for the first time applied increased surface area fractional precipitation in order to decrease the particle size of the anticancer agent paclitaxel from plant cell cultures. When compared with the case where no surface area increasing material was employed, the addition of ion exchange resin as a surface area increasing material resulted in a considerable decrease in the size of the paclitaxel precipitate. When ion exchange resin was used, the paclitaxel particles were four to five times smaller, having less than a 20 ${\mu}m$ radius, than those obtained in the absence of ion exchange resin. This is presumably because the growth of paclitaxel particles was impeded by the addition of ion exchange resin. The size of the paclitaxel precipitate also depended on the material used to increase the surface area, a result considered to be due to differences in the affinity between the particular ion exchange resin used and the paclitaxel particles. The yield of paclitaxel was significantly improved when ion exchange resin was used as a material to increase surface area. Paclitaxel, with a reduced particle size due to the addition of a surface area increasing material during the fractional precipitation process, is believed to be particularly useful for practical applications of the drug.

Characteristics of Material Removal Rate According to Discharge Area and Capacitance in MEDM (미세 방전 가공에서 방전 면적과 축전 용량에 따른 가공율 특성)

  • 박동희;류시형;김보현;주종남
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.12
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    • pp.183-190
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    • 2003
  • In this paper, investigated are the machining characteristics such as material removal rate and machining time with respect to discharge area and capacitance in micro electrical discharge machining (MEDM). As discharge area determined by the electrode size and capacitance change, the optimal feedrate to allow the minimum machining time changes. The smaller discharge area is, the lower MRR becomes because of the area effect. As the capacitance increases, MRR also increases. However there is the limit capacitance beyond which the MRR does not increase anymore. As the discharge area increases, the limit capacitance also increases.

A Study on Analysis of Accidents Cause and Prevention Policies for the Material Handling In Korea (운반하역기계의 사고발생 원인분석과 예방대책에 관한 연구)

  • 신용하;최진영
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.47
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    • pp.243-251
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    • 1998
  • These days material handling accidents and injuries are some of the most common in the workplace. 20-45% of all occupational injuries is taken place in the area of material handling industry. The control and management of material handling activities can have a significant impact on the workforce safety and productivity in the manufacturing industry. This paper is to suggest effective countermeasures for reducing and protecting occupational accidents in the area of material handling industry. To do so, firstly, we found out the relationship between occpational accidents and business. Secondly, we are to analyse overall occupational accidents caused by material handling tools. Thirdly, we found out important factors of occupational accidents and injuries in the area of material handling industry by analysing 10 cases in detail, which have been occured from 1994 to 1997 in the workplace.

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A STUDY ON DIFFERENT AMOUNT OF DENTURE BASE DISPLACEMENT USING SOFT DENTURE RELINING MATERIAL UNDER MASTICATORY FORCE (국소의치상을 위한 연성 이장재사용시 교합압에 따른 의치상 변위(Displacement)량 비교)

  • Lee, Ho-Yong
    • The Journal of Korean Academy of Prosthodontics
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    • v.36 no.1
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    • pp.18-25
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    • 1998
  • The purpose of this study was to determine how to use soft relining material by observing an amount of denture displacement according to the different base area of residual ridge and thickness of soft relining material under masticatory force. Stone models that simulated residual ridge were made with different amount of denture base area and denture was fabricated by conventional heat curing resin with usual manner on the model and relined by silicone type soft relining material with different thickness. Specimen was examined the amount of denture displacement by Instron within range of normal occlusal force. The results were as following : 1. The increasing rate of denture displacement was higher than that of soft relining material thickness. 2. The amount of denture displacement decreased 1.7 times when base area became double at same thickness of soft relining material 3. The increasing rate of denture displacement was higher than that of occlusal force

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Evaluation of Humidity Control Ceramic Board Using Gypsum Binder (석고계 바인더를 활용한 습도도절 세라믹 보드의 특성 평가)

  • Lee, Jong-Kyu;Kim, Tae-Yeon
    • Korean Journal of Materials Research
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    • v.28 no.1
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    • pp.62-67
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    • 2018
  • Active clay, bentonite and zeolite were used as porous materials for humidity controlling ceramic boards. The specific area and the pore volume of active clay were higher than bentonite and zeolite. The flexible strength of the gypsum board decreased with an increasing amount of porous material, and the flexible strength was lowest when active clay with a higher specific surface area than others porous materials was added. The specific surface area and total pore volume of ceramic boards containing porous material were highest at $102.25m^2/g$, $0.142cm^3/g$, respectively, when the active clay was added. In addition, as the amount of added porous materials increased, the specific surface area and total pore volume of the ceramic board increased, but the average pore diameter decreased. The addition of s porous materials with a high specific area and a large pore volume improved the moisture absorptive and desorptive performance of the ceramic board. Therefore, in this experiment, the moisture absorptive and desorptive properties were the best when active clay was added. Furthermore, as the amount of added porous materials increased, the moisture absorptive and desorptive properties improved. When 70 mass% of active clay was added to ${\alpha}$-type gypsum, the hygroscopicity was the highest, about $300g/m^2$, in this experiment.

A Study on Electron Beam Weldmetal Cross Section Shapes and Strength of Al 5052 Thick Plate (Al 5052 함금 후판재의 전자빔 용접부 단면 형상과 강도에 관한 연구)

  • Kim, In-Ho;Lee, Gil-Young;Ju, Jeong-Min;Park, Kyoung-Tae;Chun, Byong-Sun
    • Journal of Welding and Joining
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    • v.27 no.3
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    • pp.73-79
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    • 2009
  • This present paper investigated the mechanical properties and the microstructures of each penetration shapes classifying the conduction shape area and the keyhole shape area about electron beam welded 120(T)mm thick plated aluminum 5052 112H. As a result the penetration depth is increased linearly according to the output power, but the aspect ratio is decreased after the regular output power. In the conduction shape area, the Heat affected zone is observed relatively wider than the keyhole shape area. In the material front surface of the welded specimen, the width is decreased but the width in the material rear surface is increased. After the measuring the Micro Vikers Hardness, it showed almost similar hardness range in all parts, and after testing the tensile strength, the ultimate tensile strength is similar to the ultimate tensile strength of the base material in all the specimens, also the fracture point was generated in the base materials of all the samples. In the result of the impact test, impact absorbed energy of the Keyhole shape area is turned up very high, and also shown up the effect about four times of fracture toughness comparing the base material. In the last result of observing the fractographs, typical ductile fraction is shown in each weld metal, and in the basic material, the dimple fraction is shown. The weld metals are shown that there are no other developments of any new chemical compound during the fastness melting and solidification.

Iodine Doping of Pentacene and its Electrical Properties

  • Rahim, Abdur;Lee, Young-Kyu;Lee, Chi-Young;Lee, Jae-Gab
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2011.05a
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    • pp.238.2-238.2
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    • 2011
  • Organic thin film transistors (OTFTs) have been attracting considerable attention because of their potential use in low-cost, large area, electronic devices such as flexible displays, biochemical sensors, and smart cards. In past several years, gold/pentacene has been frequently used in OTFTs because of the high mobility of pentacene and the high work function of gold. To improve the performance of the OTFTs contact area doping of pentacene with p-doping materials are well known. In this work we demonstrated selectively contact area doping of pentacene with Iodine vapor. For effective doping elevated pentacene layer under the source-drain area was deposited and exposed to Iodine vapor. We got better electrical performance for elevated pentacene structure rather than planer structure with relatively high field-effect mobility.

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Dietary life in the 1910's in the Cheongju Area: Material use of Banchandeungsok ("반찬등속"의 식재료 사용을 중심으로 본 1910년대 청주지역의 식문화)

  • Kwon, Sun-Young
    • Journal of the Korean Society of Food Culture
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    • v.25 no.4
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    • pp.410-415
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    • 2010
  • Banchandeungsok is a book written by a person who lived in the Cheongju area located in northern Chungcheong Province. The literature is regarded as a useful source for showing types of local food in the 1910s, so it was purchased by the National Folk Museum in 2007. The writer categorized dishes described in the recipe section of the book into side dishes, snacks, rice cakes, drinks, and miscellaneous. Following this, each category was distinguished by the name of the dish, the main material, the side material, and the cooking method is presented in tables. Thus, the food culture of Chungcheong Province was arranged based on the above categorized contents. The material from the product and the outside which grow spontaneously divided with the product which flows. The case which is a product the outside, went through what kind of process and could flow toward Sangshin village in Cheongju area probably, to observe tried. The area and time were clear Eumsikdimibang and Gyuhapchongseo Jusigui with comparisons. So tried to observe the time of 1910's Cheongju area culture Dietary life time and a regional feature.

Development of the physical description area on filmstrips and slides in the British and American cataloging rules (영미계 목록규칙의 슬라이드자료에 대한 대조사항 기술형식의 변천)

  • 이창수
    • Journal of Korean Library and Information Science Society
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    • v.10
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    • pp.229-265
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    • 1983
  • Many changes have been made on the cataloging rules on filmstrips and slides all the way from the Cox's rules of 1963 to AACR 2 of 1978. The purpose of this study is to analyze eight major British and American cataloging rules on filmstrips and slides, from the results of which to identify what major changes have been made chronologically, and to clarify major differences among them in describing the form ol Physical Description Area. The findings of the study can be summarized as follows: 1. In order to make a clear distinction from one element to the other in Physical Description Area, the use of punctuation has been made more concrete. In AACR 2, various punctuations in accordance with the each element's character are used. 2. The rules on the describing the number of physical units of filmstrips have got more and more specified. 3. The descriptive form of specific material designation is closely related to the existence or nonexistence of rules on the general material designation in the body of entry. Therefore, the rules of AECT and CLA having rules on the general material designation do not use the specific material designation in Physical Description Area. On the other hand, ISBD(NBM), LA rules and AACR 2 which makes it optional to use the general material designation prescribe to use the specific material designation. 4. As for the descriptions of the physical status other than the unit and size of the filmstrips and slides, the first LC card and Cox's rules, had the color designation, and the CLA rules had sound designation. In the LA rules, AACR1(Chapter 12 Revised) and AACR 2, the detailed description of the physical status including the indication of color, sound, kind of frame, time etc. has become more and more important for Physical Description Area. 5. All the rules adopt millimetre as the measuring unit of the size of filmstrips. For the slides, most rules employ inch instead. But LA rules and ISBD(NBM) use centimeters, and AACR 2 takes either inch or centimeters. 6. Most rules, including Cox's rules, give the information on the accompanying materials. The information has been added as the last element of the Physical Description Area in the AACR 2, and recognized very important.

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A study on the material designation in library cataloging (목록에서의 자료종별표시에 관한 연구)

  • 이창수
    • Journal of Korean Library and Information Science Society
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    • v.25
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    • pp.377-404
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    • 1996
  • The purpose of this study is to investigate material designation in library cataloging and to suggest General Material Designation (GMD) and Specific Material Designation(SMD) in Korean. A summary of the study follows. In library cataloging, methods of indicating the type of material are : (1) color-coding, (2) media code as part of the call number, (3) material designation in physical description area or note area, (4) GMD and SMD. GMD is a term indicating the broad class of material to which a bibliographic item belongs. SMD is a term indicating the special class of material to which a bibliographic item belongs. GMD was listed in parenthesis following the title proper before AACR1975 code, but currently it is listed in square brackets after the AACR1975 code. AACR2 was the standard cataloging rule in GMD and SMD terminology. It is suggested that GMD be used in Korean for graphic material, sound recordings, drawings, microform, multimedia, videorecordings, manuscripts, photographs, slides, printed music, motion pictures, printed texts, objects, braille, cartographic materials, computer files and transparenies.

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