• Title/Summary/Keyword: V형

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Experimental Performance Evaluation on V-shaped Butt Welding Using GMA Welding Double Wire Reel and Remote Control Torch Welding Technique (GMAW 더블 와이어 릴, 원격제어토치 용접기술을 이용한 V형 맞대기 용접 부의 실험적 성능 평가)

  • Kim, Jeong-Hyeok;Oh, Seck-Hyeog;Lee, Hae-Gil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.2
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    • pp.1339-1347
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    • 2015
  • This study discusses a remote control torch system equipped with a GMAW double wire reel. The welding machine is 30m away from the wire feeder at the industrial site and the feeder is three to five meters away from the torch. Accordingly, the welders cannot control the current and voltage that meets the welding condition during work when they are working at a place that prevents them from seeing the control panel, such as inside a vehicle or tank or at a far work site. They also have no choice but to stop working to change the wire reel when it is burned out completely. Such work suspension resulting from frequent moves to adjust the current and voltage as well as to replace the wire and subsequent cooling causes welding defects. This study produced a remote control torch equipped with a double wire reel by simplifying and streamlining the existing GMAW functions to reduce the troubling issue. The remote control torch equipped with a double wire reel and the existing $CO_2$ /MAG welding torch were applied as a V-groove butt in the vertical position using 6mm rolled steel for a SM50A welding structure. After welding, the condition of welded surface beads underwent a visual inspection and radiographic inspection to analyze the welding quality inside the welded part. This study also evaluated the reduction of welding defects, cost saving, the replacing performance against the existing commercial welders, and the effects on possible compatibility.

Molecular Serotyping of Group B Streptococcus Isolated from the Pregnant Women by Polymerase Chain Reaction and Sequence Analysis (임신부에서 분리된 B군 연구균의 중합효소연쇄반응과 염기서열분석을 통한 혈청형 분석)

  • Oh, Chi Eun;Jang, Hyun Oh;Kim, Nam Hee;Lee, Jina;Choi, Eun Hwa;Lee, Hoan Jong
    • Pediatric Infection and Vaccine
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    • v.16 no.1
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    • pp.47-53
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    • 2009
  • Purpose : This study was performed to investigate the serotype distribution of group B streptococcus (GBS) isolated from pregnant Korean women using molecular methods. Methods : The study materials included 42 GBS isolates obtained from the vagina and anorectum of pregnant women in Goyang, Korea between 2005 and 2006. Four clinical isolates with known serotypes (Ia, Ib, III, and V) were used for validation of molecular serotyping. We used serotype-specific primers for identification of the serotypes (Ia, Ib, III, V, and VI). To determine the ambiguous serotypes by serotype-specific PCR, sequence analysis of the PCR amplicons which had been amplified with GBS-common primers was used. Results : The serotypes determined by the molecular methods agreed with the previously known 4 serotypes (Ia, Ib, III, and V). The serotypes of all 42 isolates were successfully determined by molecular methods. The distribution of the GBS serotype was as follows in order of frequency: serotype III was found in 12 isolates (28.6%), serotype V was found in 11 isolates (26.2%), serotype Ia was found in 11 isolates (26.2%), serotype VI was found in 4 isolates (9.5%), serotype Ib was found in 2 isolates (4.8%), and serotype II was found in 2 isolates (4.8%). Conclusion : Serotypes III, V, and Ia were the most frequently identified serotypes in pregnant Korean women. Molecular serotyping is useful for surveillance of the serotype distribution of GBS in colonized pregnant women and GBS diseases of neonates.

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Comparison of Splices between Bolts and Welding Spliced PHC Piles (볼트 수직이음 PHC말뚝와 용접이음 PHC말뚝의 이음부 거동 비교)

  • Kim, Myunghak;Choi, Yongkyu
    • Journal of the Korean Geotechnical Society
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    • v.34 no.12
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    • pp.93-103
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    • 2018
  • Behaviors of splices between bolts and welding spliced PHC piles using the tensile strength test were analyzed. The bolts spliced PHC piles, which were tightened over $200N{\cdot}m$ tightening torque, showed straight V shaped line at splices at the lowest 20 N load. Both sides of PHC piles stayed straight, so the full section of bolts spliced piles did not show the unifying behavior, which was the most important performance requirement as pile. Other bolts spliced PHC piles, tightened with $20N{\cdot}m$ loosening torque, also showed the same straight V shaped line at splices for each step of loading. The full section of bolts spliced piles did not return to the initial position after each step of unloading and did not show the elastic material behavior. The splices quality of bolts spliced piles is much lower than that of welding spliced piles with respect to displacement of splices during each step of loadings, residual displacements during each step of unloadings, and failure loads. Results showed that bolts spliced PHC piles, tightened with both over $200N{\cdot}m$ and as low as $20N{\cdot}m$ torque, fell short of performance requirements of spliced PHC pile.

DNA Mutation Pattern of gyrA and gyrB Genes according to the SCCmec Subtype of Quinolone-resistant Staphylococcus aureus Isolates from Blood Culture (혈액배양에서 분리된 Fluoroquinolone계 약제 내성 황색포도알균의 SCCmec 아형에 따른 gyrA와 gyrB 유전자에서의 DNA 돌연변이 양상)

  • Inwon HWANG;Sang-Ha KIM;Taewon JUNG;Young-Kwon KIM;Sunghyun KIM
    • Korean Journal of Clinical Laboratory Science
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    • v.56 no.2
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    • pp.115-124
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    • 2024
  • The emergence and spread of Staphylococcus aureus, which is resistant to quinolone antibacterial agents, has made it difficult to treat infectious diseases. Accordingly, this study examined the molecular epidemiological characteristics of quinolone-resistant S. aureus (QRSA) to obtain helpful data for treatment. Mutations in mecA and SCCmec typing, gyrA, and gyrB genes were investigated for QRSA strains isolated from the blood culture specimens at a general hospital in Daejeon Metropolitan City. The ciprofloxacin-resistant strains in SCCmec typing were II (44 strains, 73%), IVa (five strains, 8%), III, and V (one strain, 2%); the non-typeable strains (11 strains, 18%), and levofloxacin (LVX) and moxifloxacin (MXF) strains were II (44 strains, 73%), IVa (five strains, 8%), III, and V (one strain, 2%); the non-typeable strains were 10 (17%). In both gyrA and gyrB regions, there were 58 mutations, or 96.7%. In LVX, there were 56 mutations or 93.3%, and in MXF, there were 57 mutations or 95%. Twelve mutations, six mutations each in gyrA and gyrB, were identified for the QRSA strain. The resistance rate for the quinolone antibiotics of QRSA studied was approximately 98%, and 12 mutations, six each in gyrA and gyrB, were identified in the QRSA strain. Therefore, the rational use of antibiotics needs to be improved.

Larval Anisakids collected from the Yellow Corvina in Korea (참조기에서 수집된 아니사키스유충의 분류)

  • 채종일;추연명
    • Parasites, Hosts and Diseases
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    • v.24 no.1
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    • pp.1-11
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    • 1986
  • Larval anisakids found in the yellow corvina (Pseudosciaena manchurica), a marine fish caught in the Yellow Sea, were classified by their morphological types. Total 1, 068 anisakid larvae were collected from 30 fish examined, with the average number per fish of 35.6. They were classified into Anisakis type I larvae of Berland (859 in number, 80.4%), Contracaecum type A of Koyama et at. (13, 1.2%), Contra caecum type C'(new type) (55, 5.1%), Contracaecum type D of Koyama et aZ. (18, 1.7%), Contracaecum type D' (new type) (77, 7.2%), Contracaecum type V of Yamaguti (3, 0.28%), Raphidascaris sp. of Koyama et aZ. (1, 0.09%) and unidentified (42, 3.9%). Contracaecum type C' and D' were considered new in the literature.

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Whipping analysis of hull girders considering slamming impact loads (슬래밍 충격하중을 고려한 선체 휘핑 해석)

  • Seong-Whan Park;Keun-Bae Lee;Chae-Whan Rim
    • Journal of the Society of Naval Architects of Korea
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    • v.37 no.3
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    • pp.99-109
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    • 2000
  • Elastic dynamic responses analysis program for ship hulls considering slamming impact loads due to the voyage in large amplitude waves is developed. Ship hull structures are modeled by a thin-walled beam model in order to consider effects of shear deformation. The momentum slamming theory is used to derive nonlinear hydrodynamic forces considering intersection between wave particles and ship section. For the validation of the developed computer program, motions of a V-shaped simple section model and S-175 standard container model are calculated and analyzed. In each numerical example, time histories of relative displacement, velocity and vertical bending moment of a ship section are derived, considering the effect of slamming impacts in various wave conditions.ures near the free surface as well as the wake of the hydrofoil.

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Heat Transfer in a Two Wall Divergent Rectangular Channel with V-Shaped Ribs on One Wall (한 벽면에 V형 리브가 있는 2면 확대 사각채널의 열전달)

  • Lee, Myung-Sung;Ahn, Soo-Whan
    • Journal of Power System Engineering
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    • v.19 no.5
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    • pp.32-37
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    • 2015
  • The present study is to investigates the convective heat transfer characteristics and pressure drop inside the rib-roughened cooling passage of gas turbine blades. The divergent rectangular channel is fabricated with V-shaped ribs on one wall only and the inlet hydraulic diameter to outlet hydraulic diameter ratio($D_{ho}/D_{hi}$) of 1.49 is used. The current investigation has covered a Reynolds number (Re) range of 22,000~75,000, relative roughness height ($e/D_h$) of 0.1~0.2, and rib angle of attack (a) of $30^{\circ}$, $45^{\circ}$, and $60^{\circ}$ for a fixed relative pitch of 10. Results show that the Nusselt numbers are the greatest in the $60^{\circ}$-angled ribs; however, the total friction factors are the highest in the $30^{\circ}$-angled ribs.

Micro Machining Characteristics of V-shaped Single Crystal Diamond Tool with Ductile Workpiece (V형 다이아몬드공구에 의한 연질소재의 미세절삭특성 연구)

  • Hong, Sung-Min;Je, Tae-Jin;Lee, Dong-Ju;Lee, Jong-Chan
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.4 no.4
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    • pp.28-33
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    • 2005
  • Recently, trends of TFT-LCD toward larger scale and thinner thickness continue. so, demands of Light Guide Panel (LGP) which is to substitute for prism sheet are appeared. Functions of LGP obtaining polarization of light of the prism sheet as well as the incidence and reflection of light are demanded. This prism type LGP to complete functions of the existing LGP and polarization at once must be supported by micro machining technology of LGP surface. In this research, the machining characteristics of the various materials were analysed by shaping using V-shaped single crystal diamond tool. The characteristics are machined surface, machining force due to the variation of cutting depth. Used specimens are engineering materials, which are 6:4 brass, oxygen-free copper, Al6061, PC, PMMA. The FFT analysis of the measured cutting force was conducted. The cutting characteristics were analyzed and the optimum cutting conditions with materials were established.

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Biochemical Properities, Isolation & Identification of the Propionibacterium acnes Picked from Acne Lesion (여드름병변에서 채취한 Propionibacterium acnes의 분리, 동정 및 생화학적 특성 연구)

  • Lee, Kyung-Suk;Choi, Jeung-Sook
    • Fashion & Textile Research Journal
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    • v.8 no.5
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    • pp.571-576
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    • 2006
  • Thirty P. acnes were isolated from the 30 acne patients who visited some skin care shops from Feburary of 2001 to August of 2001. They were identified by morphological features (gram stain), biochemical properties. Only P. acne strains are isolated among Propionibacteria sp. and biochemical properities of P. acnes were not different from P. acnes ATCC 11827 strain significantly. The results of the biotyping was as follow: twenty three strains of biotype I from comedone, 1 strain of biotype II from pauple, 5 strains of biotype III from pauple and pustule, and 1 strain of biotype IV from pauple were isolated respectively.

The Method of Tunnel Blasting for the Vibration Control by Deck Charge and Multiple Cut (다단장약에 의한 V-cut 발파공법의 진동제어효과와 발파효율증대에 관한 연구)

  • 두준기;양형식;김형건;김용국
    • Explosives and Blasting
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    • v.21 no.3
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    • pp.1-10
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    • 2003
  • 터널굴착발파공법의 하나인 V-cut발파공법은 터널굴착기술이 발전되는 과정에서 초기에 개발되어진 기술이나 작업의 간편성과 효율성으로 인하여 많은 터널굴착공사에서 이용되고 있는 발파공법이다. V-cut발파공법은 일자유면 상태에서 V형으로 심발공을 발파하고 심발공에 의해 형성된 자유면을 이용하여 확대공으로 굴착공간을 넓히는 발파 방법이며 심발발파의 굴진장에 의해 단일발파당 굴진장이 결정된다. V-cut발파법이 개발된 이래 V-cut발파의 굴진장을 증대시키기 위한 방법으로 심발발파공의 구속저항을 감소시키기 위해 보조심발공을 발파하여 형성된 자유면에 의해 심발공의 최소저항선거리를 줄여 발파하였으나 심발공의 구속저항이 감소되지 않아 발파효율이 증대되지 않았으며 발파진동 또한 가장 크게 발생하였다. 이와 같은 현상은 최소저항선거리의 감소효과에 대한 발파기술상의 이론에 문제가 있기 때문이다. 본 연구에서는 V-cut발파법의 심발공에 대한 구속저항감소효과가 발현될 수 있는 조건들을 검토하여 최소저항선거리의 감소효과가 발현될 수 있는 조건을 제시 하여 심발공의 발파효율을 증대시키고 발파진동이 적어지는 발파방법을 제안하려 한다.