• Title/Summary/Keyword: Cutting device

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A study on machining method about molybdenum alloy micro fixing part for TEM precision specimen. (TEM 정밀 시편 제작용 몰리브덴 합금 미세 고정 부품의 제작을 위한 절삭 가공 방법에 관한 연구)

  • Kim, Ki-Beom;Lee, Chang-Woo;Lee, Hae-Jin;Ham, Min-Ji;Kim, Gun-Hee
    • Design & Manufacturing
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    • v.11 no.3
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    • pp.19-24
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    • 2017
  • In these days, increase requirement of TEM (Transmission Electro Microscope) in not only scientific field but also industrial field. Because TEM can measure inner-structure of specimen a variety of materials like metal, bio. etc. When use TEM, specimen should be thin about 50nm. So making for thin specimen, use Ion milling device that include specimen holder. The holder generally made of Aluminium Aluminium holder is worn away easily. For this reason, using time of ion milling with aluminum holder is too short. To solve the problem, we replace aluminium holer to molybdenum alloy holder. In this paper, we design molybdenum alloy holer for CAM and modify CAD modeling for effective machining process. So we array a specimen 3 by 4 and setup orientation for one-shot machining process. Next we make a CAM program for machining. we making a decision two machining strategy that chose condition of tool-path method, step-down, step-over. etc. And then conduct machining using CNC milling machining center. To make clear difference between case.1 and case.2, we fixed machining conditions like feed-rate, main spindle rpm, etc. After machining, we confirm the condition of workpiece and analysis the problems case by case. Finally, case.2 work piece that superior than case.1 cutting with WEDM because that method can not ant mechanical effect on workpiece.

Surgical Resection of Cardiac Hemangiosarcoma Using Articulated Surgical Stapler in a Dog

  • Woo-Jin Kim;Kyung-Min Kim;Won-Jong Lee;Chang-Hwan Moon;Hae-Beom Lee;Seong-Mok Jeong;Dae-Hyun Kim
    • Journal of Veterinary Clinics
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    • v.41 no.1
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    • pp.37-42
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    • 2024
  • This case report discusses the successful surgical resection of cardiac hemangiosarcoma in a dog using an articulated surgical stapler. Cardiac tumors, particularly hemangiosarcomas, have a poor prognosis. Recommended treatment involves surgical removal of the primary tumor, along with chemotherapy. However, the use of staples for cardiac tumor resection has not yet been extensively documented in the veterinary literature. A 10-year-old dachshund with pericardial effusion underwent surgery to remove a right atrial mass. An articulated linear cutting stapler was used for tumor resection. The patient experienced chylothorax as a complication but recovered well. However, the patient later developed respiratory symptoms and died, most likely due to aspiration pneumonia. The surgical stapler provided stability, convenience, and a shorter surgical time during tumor resection. Surgical resection combined with chemotherapy improves the survival of dogs with cardiac hemangiosarcoma. The stability and adjustability of the stapling device make it advantageous for cardiac tumor resection. Although complications, such as chylothorax, can arise, appropriate management can lead to positive outcomes. This case report demonstrates the feasibility and safety of using an articulated surgical stapler for cardiac tumor resection in dogs. Insights from this case can guide future research and clinical practice.

Mineral Identification and Field Application by Short Wave Infrared (SWIR) Spectroscopy (단파장적외선 분광분석법을 이용한 광물동정과 현장적용성)

  • Kim, Chang Seong;Kim, Yong-Hwi;Choi, Seon-Gyu;Ko, Kwang-Beom;Han, Kyeong-Soo
    • Economic and Environmental Geology
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    • v.50 no.1
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    • pp.1-14
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    • 2017
  • The analytical conditions including surface state, moisture effect, and device condition were investigated for applying Short Wave Infrared(SWIR) spectroscopy to the field survey. Among the three surface state of samples (exposed surface, cutting face and powder), both spectra from the exposed surface and cutting face are almost identical whereas spectral variation was detected in powder sample. Over 24-hours-dryring of the wet sample at room temperature, the samples show a similar spectrum with that of dry condition. The result suggests that outcrop samples mighty be dried for 24 ~ 48 hours depending on the wetness of outcrop. The bright minerals could produce stable spectra with 10 times measurements as default value of the device under SWIR spectroscopy but the dark minerals would require about 10 seconds, which corresponds to 100 times measurements to get the reliable spectra. The position and shape 2,160 ~ 2,330 nm and/or other spectral features of hydrothermal alteration minerals by SWIR spectroscopy could be used for a classification of hydrothermal alteration zone in the field. Absorption peaks in 2,160 ~ 2180 nm are useful for identifying (advanced) argillic zone by spectral characteristics of kaoline, dickite, pyrophyllite, and alunite. Absorption peaks in 2,180 ~ 2,230 nm are able to define muscovite, sericite, and smectite, which are key alteration minerals in phyllic zone. Absorption peaks in 2,230 ~ 2,270 nm can be used to recognize prophylitic zone where chlorite and epidote occur. Absorption peaks of other principle minerals such as talc, serpentine, amphibole, and carbonate group are mainly detected within the wave length of 2,270 ~ 2,330 nm. This result indicates that the spectra of these minerals need to be carefully interpreted.

Clinical Effects of an Improved Pump Reaction Rate and Automatic Occlusion Sensing System in Phacoemulsification (수정체유화장치의 초음파 출력속도 및 자동막힘감지 기능 향상의 술 후 임상결과 비교)

  • Kim, You Na;Lee, Jin Ah;Kim, Jae Yong;Kim, Myoung Joon;Tchah, Hung Won
    • Journal of The Korean Ophthalmological Society
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    • v.59 no.11
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    • pp.1017-1023
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    • 2018
  • Purpose: A recently introduced phacoemulsification system, the WhiteStar $Signature^{(R)}$ PRO, has demonstrated improved nucleus followability and cutting efficiency via an improved pump regulator with a higher reaction response and an automatic occlusion sensing system. In this study, we compared various phacoemulsification parameters between the new system and an older version of the device. Methods: A total of 80 eyes of 68 patients with cataracts who had undergone phacoemulsification by a single surgeon were included in this study. Forty eyes of patients underwent phacoemulsification using the older $Signature^{(R)}$ system (WhiteStar); these patients were classified as the control group. Another 40 eyes of patients underwent phacoemulsification with the newer enhanced system, the WhiteStar $Signature^{(R)}$ PRO; these patients were assigned to the experimental group. During the operation, operative parameters, including the effective phaco time (parameter of effective phaco time with a specific coefficient for the transversal movement expressed in seconds, EFX), ultrasound time (seconds [s]), effective phacoemulsification time (EPT, s), average phacoemulsification power (AVG, %), and balanced salt solution usage, were measured to determine the performance enhancement offered by the updated system. Central corneal thickness was measured before and after surgery to compare corneal edema. The relationships between the two groups were analyzed using an independent t-test. Results: The Signature $PRO^{(R)}$ system showed a lower EFX (p < 0.001), a shorter EPT (p < 0.001), and a smaller AVG (p < 0.001). Postoperative corneal thickness did not differ significantly between the two groups. Conclusions: Comparing the efficacy of the improved reaction speed of the device and automatic occlusion sensing system in performing phacoemulsification, the updated Signature $PRO^{(R)}$ system demonstrated superior followability and cutting efficiency regardless of nuclear cataract hardness.

The Effect of Surface Defects on the Cyclic Fatigue Fracture of HEROShaper Ni-Ti rotary files in a Dynamic Model: A Fractographic Analysis (Fractographic 분석을 통한 HEROShaper 니켈티타늄 전동 파일의 피로파절에 미치는 표면결함의 역할)

  • Lee, Jung-Kyu;Kim, Eui-Sung;Kang, Myoung-Whai;Kum, Kee-Yeon
    • Restorative Dentistry and Endodontics
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    • v.32 no.2
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    • pp.130-137
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    • 2007
  • This in vitro study examined the effect of surface defects on cutting blades on the extent of the cyclic fatigue fracture of HEROShaper Ni-Ti rotary files using fractographic analysis of the fractured surfaces. A total of 45 HEROShaper (MicroMega) Ni-Ti rotary flies with a #30/.04 taper were divided into three groups of 15 each. Group 1 contained new HEROShapers without any surface defects. Group 2 contained HEROShapers with manufacturing defects such as metal rollover and machining marks. Croup 3 contained HEROShapers that had been clinically used for the canal preparation of 4-6 molars A fatigue-testing device was designed to allow cyclic tension and compressive stress on the tip of the instrument whilst maintaining similar conditions to those experienced in a clinic. The level of fatigue fracture time was measured using a computer connected the system. Statistical analysis was performed using a Tukey's test. Scanning electron microscopy (SEM) was used for fractographic analysis of the fractured surfaces. The fatigue fracture time between groups 1 and 2, and between groups 1 and 3 was significantly different (p<0.05) but there was no significant difference between groups 2 and 3 (p>0.05). A low magnification SEM views show brittle fracture as the main initial failure mode At higher magnification, the brittle fracture region showed clusters of fatigue striations and a large number of secondary cracks. These fractures typically led to a central region of catastrophic ductile failure. Qualitatively, the ductile fracture region was characterized by the formation of microvoids and dimpling. The fractured surfaces of the HEROShapers in groups 2 and 3 were always associated with pre-existing surface defects. Typically, the fractured surface in the brittle fracture region showed evidence of cleavage (transgranular) facets across the grains, as well as intergranular facets along the grain boundaries. These results show that surface defects on cutting blades of Ni-Ti rotary files might be the preferred sites for the origin of fatigue fracture under experimental conditions. Furthermore this work demonstrates the utility of fractography in evaluating the failure of Ni-Ti rotary flies.

Development of Energy Harvesting Hybrid system consisted of Electrochromic Device and Dye-Sensitized Solar Cell using Nano Particle Deposition System (나노 입자 적층 시스템(NPDS)을 이용한 염료 감응 태양전지 - 전기 변색 통합 소자 및 에너지 하베스팅 시스템에 대한 연구)

  • Kim, Kwangmin;Kim, Hyungsub;Choi, Dahyun;Lee, Minji;Park, Yunchan;Chu, Wonshik;Chun, Dooman;Lee, Caroline Sunyong
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.2
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    • pp.65-71
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    • 2016
  • In this study, Antimony Tin Oxide (ATO) ion storage layer and $TiO_2$ working electrode were fabricated using Nano Particle Deposition System. NPDS is the cutting-edge technology among the dry deposition methods. Accelerated particles are deposited on the substrate through the nozzle using NPDS. The thicknesses for coated layers were measured and layer's morphology was acquired using SEM. The fabricated electrochromic cell's transmittance was measured using UV-Visible spectrometer and power source at 630 nm. As a result, the integrated electrochromic/DSSC hybrid system was successfully fabricated as an energy harvesting system. The fabricated electrochromic cell was self-operated using DSSC as a power source. In conclusion, the electrochromic cell was operated for 500 cycles, with 49% of maximum transmittance change. Also the photovoltaic efficiency for DSSC was measured to be 2.55% while the electrochromic cell on the integrated system had resulted in 26% of maximum transmittance change.

Ultrasound-guided Core Needle Biopsy in Diagnosis of Soft Tissue Masses (연부조직 종물의 진단에서 초음파 유도하 중심부 침생검)

  • Kim, Jeung-Il;Youn, Myung-Soo;Cheon, Sang-Jin;Choi, Gyung-Un;Lee, Tae-Hong
    • The Journal of the Korean bone and joint tumor society
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    • v.10 no.2
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    • pp.113-119
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    • 2004
  • Purpose: To determine the utility of sonographically guided percutaneous core needle biopsy to diagnose musculoskeletal soft tissue masses. Methods: A prospective study was performed in 55 patients referred for image-guided needle biopsy of primary or recurrent soft tissue masses and bone lesion or suspected solitary metastasis with extraosseous masses. Tissue samples were obtained with a 14-gauge or 18-gauge cutting needle coupled to an automated biopsy device under local anesthesia and sonographic guidance. Statistical analysis was based on 49 biopsies confirmed by successful clinical treatment (11 cases) or surgical resection (38 cases). Results: An accurate diagnosis was obtained in 47 (97%) of 49 biopsies; sensitivity was 95%, and specificity was 100%. The method did not yield sufficient tissue to establish a diagnosis in 6 cases. Considering all 55 biopsies, high-quality specimens were obtained in 87%. There were no serious complications. Conclusions: Sonographically guided core needle biopsy is accurate and safe, in soft tissue masses and bone tumors with extraosseous masses in the appendicular skeleton. In such patients, the sonographically guided procedure is the most prompt and effective method for obtaining tissue samples.

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Optimum Design of Jaenggi(Korean plow) Bottoms to Improve the Tillage Performance(I) -The Geometrical Characteristics of the Jaenggi Bottoms- (경운성능(耕耘性能) 향상(向上)을 위한 쟁기 이체(犂體)의 적정(適正) 설계(設計)에 관(關)한 연구(硏究) -쟁기 이체곡면(犂體曲面)의 기하학적(幾何學的) 특성(特性)-)

  • Chung, C.J.;Han, M.B.
    • Journal of Biosystems Engineering
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    • v.12 no.3
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    • pp.30-41
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    • 1987
  • The geometrical shape of a plow bottom may be the most important factor affecting the performance of a plow for a given soil and operating conditions. There are various designs of the Jaenggi (Korean plow) available commercially, which may be different from each other and from the plow (Western plow) in respect to the shape and performance. This study was intended to investigate the geometrical characteristics of Jaenggi. The coordinate digitizer equipped with 3 potentiometers was designed and manufactured for measurement of the shape of curved plane of moldboard and share. The digitizer was connected to a microcomputer having the data acquisition system. This device was used to analyze the plow bottoms of 5 differently-made Jaenggis and one cylindrical plow. The results of the study are summarized as follows: 1. It was possible to measure easily and quickly the curved plane of plow bottom and to plot the view on three major plans using the coordinate digitizer electrically connected to a microcomputer system. 2. The shape of five Jaenggi bottoms analyzed could be characterized by the cutting angle having the range of $33-42^{\circ}$, the maximum share-lift angle of $41-50^{\circ}$, and the setting angle of moldboard wing of $46-70^{\circ}$. The most critical difference of the shape factors between the Jaenggi and the plow was found in the maximum share-lift angle, the former was more than twice as much as the latter. 3. The analysis of the shape of Jaenggi bottoms showed that the share projections on 3 major plans had a varied triangle, which was quite different from that of plow bottom. Especially, it was analyzed that the shape of furrow slice for the Jaenggi had a skewed rectangle, leaving a considerable height of the ridge at the furrow bottom. 4. The dihedral angle was similar range of $30-85^{\circ}$ for the all bodies investigated, but the directional angle was somewhat different from each other. The difference in directional angle was $5^{\circ}$ for the plow, $20^{\circ}$ for the Jaenggi A and $30^{\circ}$ for the Jaenggi B. 5. Area of the spherical representation region was 0.0328 for the plow, 0.1194 for the Jaenggi A and 0.1716 for the Jaenggi B. This may indicate that the plow came close to a working surface and the Jaenggi A and the Jaenggi B departed from a working surface to a somewhat greater extent.

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A SHEAR BOND STRENGTH OF RESIN CEMENT BONDED TO HUMAN UNCUT ENAMEL, CUT ENAMEL, AND DENTIN IN VITRO

  • Lee Jong-Yeop
    • The Journal of Korean Academy of Prosthodontics
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    • v.41 no.3
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    • pp.319-324
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    • 2003
  • Statement of problem. Adhesives in dentistry playa major role in the success of restorative treatments. In the treatment of all ceramic restoration it is needed to find the adequate bond strength between enamel and dentin. Purpose. The purpose of this study was to evaluate shear bond strength of resin cement bonded to extracted human uncut enamel, cut enamel, and dentin in vitro. Material and methods. Ten freshly extracted anterior teeth without any previous restorative treatments were chosen. The extracted teeth were embedded in PMMA cold acrylic in the shape of a cylinder, 25 mm in diameter by 25 mm in height. The bonding system used was as follow: Uni-Etch (32% phosphoric acid), One-Step adhesive, Duolink resin cement. The specimens were acid etched and rinsed with water. Two layers of One-Step adhesive were coated with a disposable brush on the uncut enamel. VIP curing light at $500mV/cm^2$ was used to cure the adhesive. For cut enamel shear bond test, the specimen used for uncut enamel was further reduced approximately $0.3{\sim}0.5mm$ using a laminate preparation diamond bur (0.3 mm in depth). The specimens were subsequently treated with 320-grit SiC paper followed by 600-grit SiC paper and cleaned with distilled water. The bonding procedure on the cut enamel was same as uncut enamel bonding procedure. For dentin bonding test, the specimen used for cut enamel was further reduced approximately $0.5mm{\sim}1.0mm$ using a laminate preparation diamond bur (0.5 mm in depth of diamond cutting). The amount of reduction was evaluated with the silicone mold. The specimens were subsequently treated with 320-grit SiC paper followed by 600-grit silicon carbon paper and cleaned in distilled water. The bonding procedure on the dentin was same as uncut enamel bonding procedure. All samples were mounted and secured on the Ultradent shear bond test sample holder, and Ultradent restricted shear bond testing device was used with Universal Instron machine until fracture. Analysis of variance (ANOVA) test was performed comparing the result at P<0.05. Multiple comparison (Tukey) was used to compare each groups. Result. The result showed that the mean value in shear bond strength of resin cement bonded to uncut enamel, cut enamel and dentin were 27.04 Mpa, 30.25 Mpa and 26.39 Mpa with respect. Conclusion. Within the limitation of this study, the mean value of the shear bond strength of cut enamel was higher than those of uncut enamel or dentin. However there existed no statistical differences between three different human dentition substrates due to increased adhesive characteristics.

Fabrication and Characteristics of High Efficiency Silicon PERL (passivated emitter and rear locally-diffused cell) Solar Cells (PERL (passivated emitter and rear locally-diffused cell) 방식을 이용한 고효율 Si 태양전지의 제작 및 특성)

  • Kwon, Oh-Joon;Jeoung, Hun;Nam, Ki-Hong;Kim, Yeung-Woo;Bae, Seung-Chun;Park, Sung-Keoun;Kwon, Sung-Yeol;Kim, Woo-Hyun;Kim, Ki-Wan
    • Journal of Sensor Science and Technology
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    • v.8 no.3
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    • pp.283-290
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    • 1999
  • The $n^+/p/p^+$ junction PERL solar cell of $0.1{\sim}2{\Omega}{\cdot}cm$ (100) p type silicon wafer was fabricated through the following steps; that is, wafer cutting, inverted pyramidally textured surfaces etching by KOH, phosphorus and boron diffusion, anti-reflection coating, grid formation and contact annealing. At this time, the optical characteristics of device surface and the efficiency of doping concentration for resistivity were investigated. And diffusion depth and doping concentration for n+ doping were simulated by silvaco program. Then their results were compared with measured results. Under the illumination of AM (air mass)1.5, $100\;mW/cm^2$ $I_{sc}$, $V_{oc}$, fill factor and the conversion efficiency were 43mA, 0.6 V, 0.62. and 16% respectively.

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