• Title/Summary/Keyword: Metal printing

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The Study on The Method of Manufacturing Herbal Acupuncture (약침액(藥鍼液) 제조법(製造法)에 대한 문헌적(文獻的) 고찰(考察))

  • Lee, Jun-Hee;Lee, Sang-Ryong
    • Korean Journal of Acupuncture
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    • v.22 no.2
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    • pp.127-149
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    • 2005
  • This study is designed to investigate the method of manufacturing herbal acupuncture through literature of oriental medicine. The findings of this study are as follows; 1. The methods of manufacturing herbal acupuncture go through the process of abstraction, purification, mixing, filtration, putting and tight sealing in the container, sterilization, quality control, printing and packing 2. There are many ways to manufacturing herbal acupuncture, for example water-alcohol precipitation, alcohol-water precipitation, liquid-liquid abstract, acid-base abstract, metal base precipitation, distillation, molecular structure, polyamide absorption, dialysis, and ion exchange, etc. And popular method is water-alcohol precipitation. This is through alcohol precipitate extracting the principal ingredients from water abstraction. This is very simple and efficient way using melting characteristics of compounds in herb to water and ethanol. 3. Sterilization of herbal acupuncture is through heating-pressure, boiling, steam flowing, low temperature, filtering, radiation, cooling, and microwaves. Nowadays filtering is commonly used. And sterilization is estimated by an examination of asepsis . 4. Herbal acupuncture must be undergo study and experiment to clinical use. The problems of herbal acupuncture are turbidity, instability, causing hemolysis, pain, and fever. So many provisions (addition, sterilization, and filtration etc.) must be prepared. 5. The theory of manufacturing herbal acupuncture is from oriental medicine, not western. So it must be corresponded to oriental medical theory, for example Gimi(氣味), Guigyung(歸經), Ingyung(引經), Bosa(補瀉), and Match of Herb. It is recommended that further study of many other sided investigations in the future.

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Development of the Large-area Au/Pd Transfer-printing Process Applying Both the Anti-Adhesion and Adhesion Layers (접착방지막과 접착막을 동시에 적용한 대면적 Au/Pd 트랜스퍼 프린팅 공정 개발)

  • Cha, Nam-Goo
    • Korean Journal of Materials Research
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    • v.19 no.8
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    • pp.437-442
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    • 2009
  • This paper describes an improved strategy for controlling the adhesion force using both the antiadhesion and adhesion layers for a successful large-area transfer process. An MPTMS (3-mercaptopropyltrimethoxysilane) monolayer as an adhesion layer for Au/Pd thin films was deposited on Si substrates by vapor self assembly monolayer (VSAM) method. Contact angle, surface energy, film thickness, friction force, and roughness were considered for finding the optimized conditions. The sputtered Au/Pd ($\sim$17 nm) layer on the PDMS stamp without the anti-adhesion layer showed poor transfer results due to the high adhesion between sputtered Au/Pd and PDMS. In order to reduce the adhesion between Au/Pd and PDMS, an anti-adhesion monolayer was coated on the PDMS stamp using FOTS (perfluorooctyltrichlorosilane) after $O_2$ plasma treatment. The transfer process with the anti-adhesion layer gave good transfer results over a large area (20 mm $\times$ 20 mm) without pattern loss or distortion. To investigate the applied pressure effect, the PDMS stamp was sandwiched after 90$^{\circ}$ rotation on the MPTMS-coated patterned Si substrate with 1-${\mu}m$ depth. The sputtered Au/Pd was transferred onto the contact area, making square metal patterns on the top of the patterned Si structures. Applying low pressure helped to remove voids and to make conformal contact; however, high pressure yielded irregular transfer results due to PDMS stamp deformation. One of key parameters to success of this transfer process is the controllability of the adhesion force between the stamp and the target substrate. This technique offers high reliability during the transfer process, which suggests a potential building method for future functional structures.

Improvement of solar cell efficiency using selective emitter (Selective emitter를 이용한 태양전지 효율 향상)

  • Hong, Kuen-Kee;Cho, Kyeong-Yeon;Seo, Jae-Keun;Oh, Dong-Joon;Shim, Ji-Myung;Lee, Hyun-Woo;Kim, Ji-Sun;Shin, Jeong-Eun;Kim, Ji-Su;Lee, Eun-Joo;Lee, Soo-Hong;Lee, Hae-Seok
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.56-59
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    • 2011
  • The process conditions for high efficiency industrial crystalline Si solar cells with selective emitter were optimized. In the screen printed solar cells, the sheet resistance must be 50-60V/sq. because of metal contact resistance. But the low sheet resistance causes the increase of the recombination and blue response at the short wavelength. Therefore, the screen printed solar cells with homogeneous emitter have limitations of efficiency, and this means that the selective emitter must be used to improve cell efficiency. This work demonstrates the feasibility of a commercially available selective emitter process, based on screen printing and conventional diffusion process. Now, we improved cell efficiency from 18.29% to18.45% by transition of heavy emitter pattern and shallow emitter doping condition.

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Investigation on Interfacial Microstructures of Stainless Steel/Inconel Bonded by Directed Energy Deposition of alloy Powders (레이저 직접 용착공정으로 형성된 스테인레스/인코넬 합금 계면의 미세조직 분석)

  • Eom, Yeong Seong;Kim, Kyung Tae;Jung, Soo-Ho;Yu, Jihun;Yang, Dong Yeol;Choe, Jungho;Sim, Chul Yong;An, Seung Jun
    • Journal of Powder Materials
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    • v.27 no.3
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    • pp.219-225
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    • 2020
  • The directed energy deposition (DED) process of metal 3D printing technologies has been treated as an effective method for welding, repairing, and even 3-dimensional building of machinery parts. In this study, stainless steel 316L (STS316L) and Inconel 625 (IN625) alloy powders are additively manufactured using the DED process, and the microstructure of the fabricated STS316L/IN625 sample is investigated. In particular, there are no secondary phases in the interface between STS316L and the IN625 alloy. The EDS and Vickers hardness results clearly show compositionally and mechanically transient layers a few tens of micrometers in thickness. Interestingly, several cracks are only observed in the STS 316L rather than in the IN625 alloy near the interface. In addition, small-sized voids 200-400 nm in diameter that look like trapped pores are present in both materials. The cracks present near the interface are formed by tensile stress in STS316L caused by the difference in the CTE (coefficient of thermal expansion) between the two materials during the DED process. These results can provide fundamental information for the fabrication of machinery parts that require joining of two materials, such as valves.

An Image Characteristics of Metal Movable Type Printing on One Hundred Poets of the Tang Dynasty by the Measurement of 3D Digital Microscope (3D 디지털 현미경으로 측정한 당백가시 인쇄본의 형상 특징)

  • Kim, Heakyoung;Okada, Yoshihiro
    • Journal of Conservation Science
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    • v.33 no.1
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    • pp.43-49
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    • 2017
  • The ancient paper document we chose as a case study for our research is "One Hundred Poets of the Tang Dynasty", which is housed in the Ryukoku University Library. The purpose of this research is to introduce a method to analyze the surface roughness and microstructure at a high resolution. In addition, we attempt to quantitatively measure the surface unevenness of the types and curve structure. We used a tridimensional digital microscopy as a non-contact and a non-destructive method to study ancient cultural paper. The information contained in the paper may be lost in the process of applying strong pressure to clean and lining or press. However, this microscopic measurement method can non-destructively analyze a large amount of data in old printed books. Moreover, it enables observing them directly with reflected light. Therefore, this method may be useful for collecting printed information remaining on the surface of the paper.

Preparation and Electrochemical Performance of 1.5 V and 3.0 V-Class Primary Film Batteries for Radio Frequency Identification (RFID)

  • Lee, Young-Gi;Choi, Min-Gyu;Kang, Kun-Young;Kim, Kwang-Man
    • Journal of Electrochemical Science and Technology
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    • v.1 no.1
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    • pp.39-44
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    • 2010
  • 1.5 V and 3.0 V-class film-type primary batteries were designed for radio frequency identification (RFID) tag. Efficient fabrication processes such as screen-printings of conducting layer ($25{\mu}m$), active material layer ($40{\mu}m$ for anode and $80{\mu}m$ for cathode), and electrolyte/separator/electrolyte layer ($100{\mu}m$), were adopted to give better performances of the 1.5 V-class film-type Leclanch$\acute{e}$ primary battery for battery-assisted passive (BAP) RFID tag. Lithium (Li) metal is used as an anode material in a 3.0 V-class film-type $MnO_2||$Li primary battery to increase the operating voltage and discharge capacity for application to active sensor tags of a radio frequency identification system. The fabricated 3.0 V-class film-type Li primary battery passes several safety tests and achieves a discharge capacity of more than 9 mAh $cm^{-2}$.

Fabrication of $SnO_2$ Gas Sensor added by Metal Oxide for DMMP (DMMP 검출용 금속산화물을 첨가한 $SnO_2$ 가스센서 제조)

  • 최낙진;반태현;곽준혁;백원우;김재창;허증수;이덕동
    • Journal of the Korea Institute of Military Science and Technology
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    • v.6 no.3
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    • pp.54-61
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    • 2003
  • $SnO_2$ gas sensor for the detection DMMP, simulant of nerve gas was fabricated and its characteristics were examined. Sensing materials were $SnO_2$ added by TEX>$\alpha$-$Al_{2}O_{3}$ with 0∼20wt.% and $In_{2}O_{3}$ with 0∼3wt.% and were physically mixed each material. They were deposited by screen printing method on alumina substrate. The sensor was consisted of sensing electrode with interdigit(IDT) type in front and a heater in back side. Its dimension was 7$\times$10$\times$0.6$\textrm{mm}^2$. Crystallite size 8t phase identification, specific surface area and morphology of fabricated $SnO_2$ powders were analyzed by X-ray diffraction(XRD), surface area analyzer(BET) and by a scanning electron microscope(SEM), respectively. Sensor was measured as flow type and sensor resistance change was monitored as real time using LabVIEW program. The best sensitivities were 75% at adding 4wt.% TEX>$\alpha$-$Al_{2}O_{3}$, operating temperature $300^{\circ}C$ and 87% at adding 2wt.% $In_{2}O_{3}$, operating temperature $350^{\circ}C$ to DMMP 0.5ppm. Response and recovery times were about 1 and 3 min., respectively. Repetition measurement was very good with $\pm$3% in full scale. As a result, operating temperature was lower TEX>$\alpha$-$Al_{2}O_{3}$ than $In_{2}O_{3}$, but sensitivity was higher $In_{2}O_{3}$ than $\alpha$-$Al_{2}O_{3}$.

A Study on the Orientalism Expressed in the Fashion of 1990's (1990년대 패션에 나타난 오리엔탈리즘에 관한연구)

  • 은영자
    • Journal of the Korean Society of Costume
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    • v.43
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    • pp.259-282
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    • 1999
  • To analyze the characteristics of Orientalism which is expressed in the fashion of the 1990's this study was examined according to three aspects such as form textiles and pattern and the aspects was considered with regard to Chinese Indian Japanese Korean, Southeas Asian and North African style. 1. In form Orientalism which is influenced by latest other fashion trend; Naturalism and Minimalism is expressed as a comfortable casual style which simplifies the way of wearing and mixes the characteristic elements of folk costume with western costume. The way of layerd wearing like knotting wrapping draping and the symbolic from which is inspired by the unique are of each country are shown. 2. In textiles Chinese Japanese and Indian silk as well as Southeast Asian and North African cotton show a splendid oriental impression using vivid color. On the other hand the linens of Korea like hemp and ramie emphasize natural characteristics and show a simple and unartificial oriental beauty. But in the use of material and color it shows a remarkable tendency to break the preconceived idea by coordinating a luxurious silk with a practical denim or harmonizing technical new-masterials with traditional materials. 3. In pattern the decorative elements of Orientalism such as a traditional pattern skills to dye embroidery and other decorations are emphasized on the form of western costume. The sketchy patterns of Chinese Korean and Japanese styles which include the pattern of a flower a bamboo and a butterfly are expressed using embroidery or textile printing. The geometrical seriate patterns of Southeast Asian and North African styles use traditional dyeing methods like Batik. Also the Indian technique of decoration like Mirro Work satisfies handcrafted royalty and feminine romantic taste in modern minimal fashion. The Orientalism expressed in the fashion of 1990's emphasizes the characteristics of people wearing colthing which break the preconceived idea by simplifying the form harmonizing differences between oriental and western cultures and mixing the elements of traditional costumes among countries. Most of all. Ethno using geonmetrical seriate pattern and technical new metal material and Romantic Ethnic using flower embroidery precious stones and beads are appearing as a distinctinve feature.

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Study on Tensile Properties of AlSi10Mg produced by Selective Laser Melting (SLM 공정 기법으로 제작한 AlSi10Mg 인장특성에 관한 연구)

  • Kim, Moosun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.12
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    • pp.25-31
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    • 2018
  • Selective Laser Melting is one of the representative 3D printing techniques for handling metal materials. The main factors influencing the characteristics of structures fabricated by the SLM method include the build-up angle of structures, laser power, laser scan speed, and scan spacing. In this study, the tensile properties of AlSi10Mg alloys were investigated by considering the build-up angle of tensile test specimens, laser scanning speed and scan spacing as variables. The yield stress, tensile strength, and elongation were considered as tensile properties. From the test results, it was confirmed that the yield stress values were lowered in the order of 0, 45, and 90 based on the manufacturing direction of the tensile specimen. The maximum yield stress value was obtained at 1870 mm / min based on the laser scan speed. The yield stress size decreased with decreasing scan speed. Based on the laser scan spacing, as the value increases, the yield stress increases, but the variation is smaller than the other test criteria. The tendency of the tensile strength and elongation variation depending on the test conditions was difficult to understand.

Wear of 3D printed and CAD/CAM milled interim resin materials after chewing simulation

  • Myagmar, Gerelmaa;Lee, Jae-Hyun;Ahn, Jin-Soo;Yeo, In-Sung Luke;Yoon, Hyung-In;Han, Jung-Suk
    • The Journal of Advanced Prosthodontics
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    • v.13 no.3
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    • pp.144-151
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    • 2021
  • PURPOSE. The purpose of this in vitro study was to investigate the wear resistance and surface roughness of three interim resin materials, which were subjected to chewing simulation. MATERIALS AND METHODS. Three interim resin materials were evaluated: (1) three-dimensional (3D) printed (digital light processing type), (2) computer-aided design and computer-aided manufacturing (CAD/CAM) milled, and (3) conventional polymethyl methacrylate interim resin materials. A total of 48 substrate specimens were prepared. The specimens were divided into two subgroups and subjected to 30,000 or 60,000 cycles of chewing simulation (n = 8). The wear volume loss and surface roughness of the materials were compared. Statistical analysis was performed using one-way analysis of variance and Tukey's post-hoc test (α=.05). RESULTS. The mean ± standard deviation values of wear volume loss (in mm3) against the metal abrader after 60,000 cycles were 0.10 ± 0.01 for the 3D printed resin, 0.21 ± 0.02 for the milled resin, and 0.44 ± 0.01 for the conventional resin. Statistically significant differences among volume losses were found in the order of 3D printed, milled, and conventional interim materials (P<.001). After 60,000 cycles of simulated chewing, the mean surface roughness (Ra; ㎛) values for 3D printed, milled, and conventional materials were 0.59 ± 0.06, 1.27 ± 0.49, and 1.64 ± 0.44, respectively. A significant difference was found in the Ra value between 3D printed and conventional materials (P=.01). CONCLUSION. The interim restorative materials for additive and subtractive manufacturing digital technologies exhibited less wear volume loss than the conventional interim resin. The 3D printed interim restorative material showed a smoother surface than the conventional interim material after simulated chewing.