• Title/Summary/Keyword: TEM Journal

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Shear Strength and Aging Characteristics in Solder Bumps for High Reliability Optical Module (고신뢰성 광모듈을 위한 솔더 범프의 전단강도와 시효 특성)

  • 유정희
    • Journal of Welding and Joining
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    • v.21 no.2
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    • pp.97-101
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    • 2003
  • The change of microstructures in the base metal during transient liquid phase bonding process of directionally Ni base superalloy, GID-111 was investigated. Bonds were fabricated using a series of holding times(0~7.2ks) at three different temperatures. The flip chip bonding utilizing self-aligning characteristic of solder becomes mandatory to meet tolerances for the optical device. In this paper, a parametric study of aging condition and pad size of samples was evaluated. A TiW/Cu/electroplated Cu UBM structure was selected and the samples were aging treated to analyze the effect of intermetallic compounds with the time variations. An FIB technique was applied to the preparation of samples for TEM observations. An FIB technique is very useful to prepare TEM thin foil specimens from the solder joint interface. After aging treatment, the tendency to decrease in shear strength was measured and the structure of the solder and the UBM was observed by using SEM, TEM and EDS. As a result, the shear strength was decreased of about 21% in the 100${\mu}{\textrm}{m}$ sample at 17$0^{\circ}C$ aging compared with the maximum shear strength of the sample with the same pad size. In the case of the 12$0^{\circ}C$ aging treatment, 18% of decrease in shear strength was measured at the 100${\mu}{\textrm}{m}$ pad size sample. An intermetallic compound of Cu6Sn5 and Cu3Sn were also observed through the TEM measurement by using.

6H-SiC single crystal growth by the sublimation method : (II) the analysis of internal defects (승화법에 의한 6H-SiC 단결정 성장 : (II) 내부 결함 해석)

  • Kim, Hwa-Mok;Kang, Seung-Min;Joo, Kyoung;Shim, Kwang-Bo;Auh, Keun-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.7 no.2
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    • pp.191-196
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    • 1997
  • The micro-defects in the SiC single crystals were characterized using a variety of the microscopic techniques (OM, TEM, AFM). It was observed that the hexagonal-plate precipitates and the longitudinal micropipes are present inside of SiC wafers. TEM results exhibited that there are amorphous phase in the SiC wafer and the phase were originated from the formation of the nonstoichiometric $Si_{1-x}_xC_x$ phases during growth process.

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Performance Characteristics of Thermoelectric Generator Modules For Parallel and Serial Electrical Circuits (전기회로 구성 방법에 따른 열전발전 모듈 성능 특성)

  • Kim, Yun-Ho;Kim, Myung-Kee;Kim, Seo-Young;Rhee, Gwang-Hoon;Um, Suk-Kee
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.22 no.5
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    • pp.259-267
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    • 2010
  • An experiment has been performed in order to investigate the characteristics of multiple thermoelectric modules (TEMs) with electrical circuits. The open circuit voltage of TEM connected parallel circuit is equal to the sum of individual TEMs. In contrast, the open circuit voltage is equal to the average of that individual TEM for a series circuit. The power output and conversion efficiency of TEM for both parallel and series circuits increase as the operating temperature conditions for individual TEMs becomes identical. Comparing parallel with series circuits, the power generation performance is more excellent for series circuit than parallel circuit. This result is attributed to the power loss from the TEM with better power generation performance.

Implementation of the Web-Based K-LOSA Program for the Safety Observation in Normal Operation (정상운항에서 안전 관찰을 위한 웹 기반 K-LOSA 프로그램 구현)

  • Choi, Youn-Chul;Hong, Seung-Beom
    • Journal of Advanced Navigation Technology
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    • v.18 no.4
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    • pp.319-324
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    • 2014
  • Line operation safety audit (LOSA) is the proactive data collection system to capture the accident and serious incident caused by flight crew and is the safety management program for collecting threat error management (TEM) and crew resource management (CRM) during normal operations. The typically LOSA is written by hand, manages and archives the LOSA Observation Worksheet. But, this method is not easy to archive and ensure confidentiality of the LOSA worksheets. As we implemented the K-LOSA of the web-document type instead of the existing LOSA archive method and change the TEM category code. we yields to archive the efficient data management and confidentiality. In this paper, we introduce the LOSA and to configure the K-LOSA program.

The Study on Common Factors of Typical CFIT Accident with Go-around Failure and Go-around Gate Operation of Foreign Carriers (An Analysis of Korean CFIT Accidents through TEM) (복행실패로 발생한 CFIT사고의 공통요인 및 외항사 복행게이트 운영 실태에 대한 연구 (한국 대표적 CFIT사고의 TEM 분석을 중심으로))

  • Choi, Jin-Kook
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.22 no.3
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    • pp.15-23
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    • 2014
  • There have been CFIT(Controlled Flight Into Terrain) accidents that can be prevented if the crew executed go-around. This study is to analyse the common factors of three typical CFIT accidents of Korea in TEM(threat and error management) frame, and the examples of go-around gate and the countermeasures of eight airlines through the survey facilitating go-around to prevent CFIT. The common factors found in three typical CFIT accidents occurred in Korea or by Korean carriers turned out to be in mountainous terrain, in bad weather while in non-precision approach or circling approach by captain as PF(Pilot Flying) when crew make monitoring errors and communication errors. It also turned out that the crew in all three typical tragic CFIT accidents did not execute go-around in unstabilized approaches. The captains did not respond immediately when first officers advised them to go-around until it is too late. Seven out of eight Airlines answered that they use stabilized approach height as 1,000 feet to be stabilized earlier to have more safety margin by enhancing go-around gate regardless of the weather to prevent CFIT in the survey.

Syntheses and Characterizations of Valine and Alanine Capped Water Soluble ZnS Nanoparticles (Valine 및 Alanine 분자로 표면 처리된 수용성의 ZnS 나노입자의 합성 및 특성연구)

  • Lee, Sang-Min;Kim, Ki-moon;Hwang, Cheong-Soo
    • Journal of the Korean Chemical Society
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    • v.53 no.5
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    • pp.505-511
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    • 2009
  • Water soluble ZnS nanocrystals were synthesized by capping the surface of the nanocrystals with valine and alanine molecules, which are structurally simple and bio friendly amino acids. The obtained ZnS nanocrystal powders were characterized by XRD, HR-TEM, and EDXS spectroscopies. The measured particle sizes by HR-TEM images were in the range of 3.3 to 3.6 nm. In addition, the surface capping amino acids molecules were characterized by FT-IR and FT-Raman spectroscopies.

A study on the characteristics on the error of the flight crew (운항승무원 실수 특성에 관한 연구 : LOSA를 중심으로)

  • Choi, Jin-Kook;Kim, Chil-Young
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.17 no.2
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    • pp.62-67
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    • 2009
  • LOSA is a flight safety program that analyses human errors in normal operations. Trained pilot observers monitor the normal flights at the observer seat. LOSA is a proactive non jeopardy data collection tool using threat and error management(TEM) as a framework. With the analysis of crew behaviors through LOSA with The LOSA collaborative(TLC), the airlines can identify the behaviors of the crew during normal operations. The major objective of LOSA is to measure how the crew manage threats, errors and undesired aircraft deviations in the cockpit on day to day operations. The airlines are able to set up effective TEM training with practical six generation Crew recourse management(CRM) with data of error from LOSA instead of theoretical CRM courses. The Airlines can use TEM as an integral part of a Safety Management System(SMS) and uses monitoring and cross-checking skills in the flight operations to manage threats and errors effectively when we know the errors we make in the cockpit on daily operation. The result of LOSA indicates that the error detection rate should be enhanced since around the half of the errors went undetected. The areas which should be focused for enhancing the error detection are monitor, cross-check, the management of workload, automation and taxiway/ runway to manage errors effectively.

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A Study on the Muscovite-Pyrophyllite Mixed Phase in the Shale from the Manhang Formation, Taebaek Area (태백지역 만항층 셰일에서 산출되는 백운모-파이로필라이트 혼합상에 대한 연구)

  • Choi, Seung-Hyun;Mun, Hyang-Ran;Lee, Young-Boo;Lee, Jung-Hoo
    • Journal of the Mineralogical Society of Korea
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    • v.24 no.4
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    • pp.313-320
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    • 2011
  • Mica-type phyllosilicate particles in the shales of the Manhang formation at the Taeback area in the Kangwon Province were studied using electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). The average chemical formula of the mica-type phyllosilicate mineral analysed by EPMA is $K_{1.35}(Fe_{0.18}Mg_{0.03}Al_{3.86})(Si_{6.55}Al_{1.45})O_{20}(OH)_4$. Low K contents compared to the ideal chemistry of muscovite indicate the presence of illite in the mica-type phyllosilicate particle. X-ray diffraction study showed that pyrophyllite commonly coexists with muscovite in the shales from the Manhang Formation. TEM observations showed both the interlayer and intralayer mixing of $9.3-{\AA}$ pyrophyllite and $10-{\AA}$ muscovite layers. The low K content of the mica-type phyllosilicates apparently come from the close mixing of pyrophyllite and muscovite.

Extended-Spectrum $\beta$-lactamase Genes Acquired Multidrug-Resistant Klebsiella pneumoniae in a Dog and Its Owner (개와 보호자에서 Extended-Spectrum $\beta$-lactamase 유전자를 획득한 다약제내성 Klebsiella pneumoniae)

  • Han, Jae-Ik;Jang, Hye-Jin;Kim, Gon-Hyung;Chang, Dong-Woo;Na, Ki-Jeong
    • Journal of Veterinary Clinics
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    • v.27 no.2
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    • pp.125-129
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    • 2010
  • A 2-year-old female Pomeranian dog was referred with multiple pelvic fractures. The surgical correction was performed for the fractures. However, after the surgery, purulent exudation was occurred in the surgical site. Antibiotic susceptibility test revealed that the isolated bacteria are resistant to penicillins, cephalosporins, aminoglycosides, quinolones, and trimethoprim/sulfamethoxazole. Bacterial identification and extended-spectrum $\beta$-lactamase (ESBL) confirming test indicated that the isolated bacteriae is ESBL-producing Klebsiella pneumoniae. Minimum inhibitory concentration (MIC) and maximum bactericidal concentration (MBC) tests revealed that meropenem, one of carbapenems, is the only effective antibiotic. The patient was treated with meropenem for 5 days. After 10 days, the exudation was disappeared and the infection was cured. The molecular typing of the ESBL revealed that TEM-1 ESBL is present in the bacteria isolated from the patient. The bacteria isolated from the owner's palm also revealed that TEM-1 and SHV-1 ESBLs are present.

Characterization of Extended Spectrum $\beta$-Lactamase Genotype TEM, SHV, and CTX-M Producing Klebsiella pneumoniae Isolated from Clinical Specimens in Korea

  • Kim Yun-Tae;Kim Tae-Un;Baik Hyung-Suk
    • Journal of Microbiology and Biotechnology
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    • v.16 no.6
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    • pp.889-895
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    • 2006
  • To investigate the antibiotic-resistant patterns and the gene types of extended-spectrum $\beta$-lactamase (ESBL)-producing Klebsiella pneumoniae, we collected 226 Klebsiella pneumoniae strains from three general hospitals with more than 500 beds in Busan, Korea from September 2004 to October 2005, The minimum inhibitory concentration (MIC) of antibiotics was measured using the Gram-negative susceptibility (GNS) cards of Vitek (Vitek system, Hazelwood Inc., MO, U.S.A.). Of the 226 K, pneumoniae isolates, 65 ESBL-producing K. pneumoniae strains were detected by the Vitek system and confirmed by the double-disk synergy test. TEM (Temoniera) type, SHV (sulfhydryl variable) type, and CTX-M (cefotaxime) type genes were detected by polymerase chain reaction. All 65 K. pneumoniae strains were resistant to ampicillin, cefazolin, cefepime, ceftriaxone, and aztreonam, and 83.0% of the organisms were resistant to ampicillin/sulbactam, 66.1% to tobramycin, 67.6% to piperacillin/tazobactam, 61.5% to ciprofloxacin, and 47.6% to trimethoprim/sulfamethoxazole, and 43.0% to gentamicin. TEM-type ESBLs (TEM-1 type, -52 type) were found in 64.6% (42 of 65) of the isolates, SHV-type ESBLs (SHV-2a type, -12 type, -28 type) in 70.7% (46 of 65) of isolates, and CTX-M-type ESBLS (CTX-M-15 type) in 45% (29 of 65) of isolates. Of the 65 ESBL-producing K. pneumoniae strains, two strains were found to harbor blaSHV-28, which were detected in Korea for the first time. Therefore, more investigation and research on SHV-28 are needed in order to prevent the ESBL type-producing K. pneumoniae from spreading resistance to oxyimino cephalosporin antibiotics.