• 제목/요약/키워드: Internal inclusion

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트럭용 커낵팅 로드 소재의 내부 품질에 따른 절삭 특성 연구 (A Study on the Machining Characteristics by the Internal Quality of Conecting Rod's Meterials for Trucks)

  • 김동현
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1996년도 춘계학술대회 논문집
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    • pp.97-101
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    • 1996
  • In this paper, We have studied internal quality incluiding chemical compositions, microscopic structrue and nonmetalic inclusion of test materials. We have analyzed dynamic characteristics of cutting resistence including tensile strength value, hardeness value, impact value etcs. We have compared chip treatments of test materials. In analyzing internal quality, all of test materials have typical ferrite+pearlite structure. But, nonmetallic inclusion have oxide and sulfide inclusion in medium carbon steels, mainly sulfide inclusion is existed in S-free cutting steels. In Ca+S-free cutting steels, calcium aluminate and sulfide complex inclusion, had low-melting points, as deformation of sulfide and oxide inclusion is existed. machining characteristics, cutting resistence is maximum in Ca+S-free cutting steels, minimum in medium carbon steels. Chip treatements are excellent in S-free cutting steels, similar to the Ca+S free cutting steels and medium carbon steels.

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디젤 엔진용 캠축 소재의 금속적 특성 및 선삭 가공 특성에 관한 연구 (Turning and Metalic Characterization for CAM Shaft Materials of Diessel Engine)

  • 채왕석;김경우;김동현
    • 한국정밀공학회지
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    • 제14권7호
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    • pp.22-28
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    • 1997
  • In this paper, We have studied internal quality incluiding chemical compositions, microscopic structure and nonmetalic inclusion of test material. We have analyzed dynamic characteristics of cutting resistence and compared chip treatment of the test material. In analyzing internal quality, all of the test material have typical ferrite+pearlite structure. But, nonmetallic inclusion has oxide and sulfide inclusion has oxide and sulfide inclusion in medium carbon steel, mainly sulfide inclusion is existed in S-free cutting steel. In Ca+S-free cutting steel, calcium aluminate and sulfide complex inclusion, had low-melting point, as deformation of sulfide and oxide inclusion is existed. Machining characteristics, cutting resistence is maximum in medium carbon steel. Chip treatement are excellent in S-free cutting steel, similar to the Ca+S free cutting steel and medium carbon steel.

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트럭용 커넥팅 로드 소재의 내부 품질에 따른 기계적 특성 연구 (A study on the Mechanical Characteristics by the Internal Quality of Connecting Rod Materials for Trucks)

  • 김동현
    • 한국생산제조학회지
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    • 제7권1호
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    • pp.75-81
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    • 1998
  • We have studied internal quality including chemical compositions, microscopic structure and nonmetallic inclusion of test materials. We have analyzed tensile strength value, hardness value, impact value etc. In analyzing internal quality, all of the test materials showed typical ferrite+pearlite structure. But nonmetallic inclusion showed oxide and sulfide inclusions in medium carbon steels, and sulfide inclusion is S-free cutting steels. In ca+ S-free cutting steels, the calcium aluminate and sulfide complex inclusion had low-melting points as deformation of sulfide and oxide inclusion is existed. It was found that tensile strength and hardness give maximum value in medium carbon steels, where as minimum in Ca + -free cutting steels. But values of elongation, reduction of area impact are reverse. Fracture surface of impact specimen is ductile in free cutting steels but brittle in medium cabon steels.

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INFLUENCE OF INCLUSION ON INTERNAL DEFECT IN MULTI-STAGE EXTRUSION

  • Yoshida Y.;Fukaya Y.;Yukawa N.;Ishikawa T.;Ito K.
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 The 8th Asian Symposium on Precision Forging ASPF
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    • pp.51-54
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    • 2003
  • Internal defects such as chevron crack occasionally occur in the process of cold extrusion or cold drawing. It is known that the existence and property of inclusion greatly influences the generation of the internal crack. However, in the plastic working field, research about the effect of the inclusion on the fracture is not theoretically analyzed. This paper describes effects of the physical property of inclusion on the internal fracture generation in the process. Prediction of fracture was evaluated by critical damage value calculated by the equation of Cockcroft & Latham and its change by the inclusion physical property such as size and stiffness was investigated.

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된장의 향미에 미치는 ${\beta}-cyclodextrin$의 포접효과 (Effects of ${\beta}-cyclodextrin$ inclusion on the flavor of Doenjang)

  • 김혜영B;김순미
    • 한국식생활문화학회지
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    • 제16권4호
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    • pp.316-322
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    • 2001
  • This study was performed to investigate flavor modification effects of ${\beta}-cyclodextrin$ $({\beta}-CD)$ inclusion complex on the flavor of Doenjang (Korean traditional fermented soy paste) with various substitution levels of 10, 20, and 30%. Water and protein contents of the substituted samples showed significantly lower values compared to those of control(p<0.05). Results of DSC(Differential Scanning Calorimetry) showed that significantly higher ${\Delta}H$ values (386.03 and 304.23) in the 20 and 30% substituted samples represented the stabilized internal cell structures(p<0.05). Internal structures observed with the scanning electronic microscope tended to be less rough and organized making even and ordered internal cell structures as the substitution levels were increased. Results of sensory evaluation showed significantly higher savory flavor and significantly lower bitter and astringent flavors with the substituted samples compared to those of control(p<0.05). Results from this study showed the substitutions of ${\beta}-CD$ could possibly modify unfavored flavors of Doenjang while keeping the unique, nutritional and functional properties when ${\beta}-CD$ was used as a flavor modifier.

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MYH9 nephropathy

  • Oh, Taehoon;Seo, Hyun Jung;Lee, Kyu Taek;Kim, Han Jo;Kim, Hwi Jun;Lee, Ji-Hye;Cheong, Hae Il;Lee, Eun Young
    • Kidney Research and Clinical Practice
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    • 제34권1호
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    • pp.53-56
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    • 2015
  • MYH9-related disorder is an autosomal dominant disease caused by a mutation in the MYH9 gene, which encodes nonmuscle myosin heavy chain IIA (NMMHC-IIA). This disease is characterized by giant platelets, thrombocytopenia, granulocyte inclusion bodies, proteinuria, and high-pitch sensorineural deafness. Nephropathy has been observed in 30% of patients with MYH9-related disorder. The characteristic features are early onset proteinuria and rapidly progressing renal disorder. However, the prognosis of MYH9 nephropathy remains unclear. Herein, we describe a 36-year-old woman who presented with proteinuria and was diagnosed with MYH9 nephropathy via renal biopsy and gene analysis. Her proteinuria improved after administration of an angiotensin II receptor blocker, but was aggravated after changing to a calcium channel blocker.

감기 임상시험 가이드라인 제정을 위한 최신 임상시험 연구 분석 (Analysis of Recent Clinical Studies to Establish Korean Herbal Medicine Clinical Trial Guidelines for the Common Cold)

  • 김관일;이호정;이범준;정희재;정승기;이준희
    • 대한한방내과학회지
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    • 제37권1호
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    • pp.109-134
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    • 2016
  • Objectives: The aim of this study was to help develop a guideline for the common cold. We searched recent clinical studies of the common cold in Western medicine and reviewed their objectives, inclusion and exclusion criteria, primary outcome, secondary outcome, and assessment tools to establish evidenced-based guideline.Methods: We searched electronic databases (Cochrane Library, MEDLINE, EMBASE) to identify eligible randomized controlled trials (RCTs) about the common cold for the last 10 years. We included 29 RCTs and showed their research summary via their objectives, participants, interventions, control, treatment duration, and results. We also analyzed the definition of the common cold presented in the article, inclusion and exclusion criteria, primary and secondary outcomes, and assessment tools.Results: We reported the aforementioned areas in detail. At first, the definition of the common cold was confused across the articles. Second, herbal medication clinical trials for the common cold have been extensively studied recently. Third, the eligibility criteria frequently included the Jackson Symptom score. Fourth, validated assessment tools (i.e., the Wisconsin Upper Respiratory Symptom Survey-21) have only been used in a few recent studies.Conclusions: Our research will be helpful to establish Korean herbal medicine clinical trial guidelines for the common cold.

근감소증에 대한 한약 치료 : 체계적 문헌 고찰 (Herbal Medicine for Sarcopenia: A Systematic Review of Randomized Controlled Trials)

  • 천세은;이수형;신용진;신선호
    • 대한한방내과학회지
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    • 제44권6호
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    • pp.1118-1138
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    • 2023
  • Objectives: Sarcopenia is an age-associated skeletal muscle disorder that can profoundly impact the health of elderly people. However, the efficacy of herbal medicine in sarcopenia is uncertain. This review aims to investigate evidence of the effect of herbal medicine on sarcopenia. Methods: We systematically searched 12 electronic databases for relevant randomized controlled trials (RCTs). Only trials that met the inclusion criteria were selected, and the characteristics of the included studies were extracted and synthesized in a narrative manner. The quality of the included studies was assessed using Cochrane's Risk of Bias (RoB) 2.0 tool. Results: 7 RCTs involving 672 participants with sarcopenia met the inclusion criteria. The intervention combining herbal medicine and conventional treatment (i.e., exercise, nutritional support) had a significant therapeutic effect compared with the conventional treatment, showing improvement in muscle strength (i.e., grip strength), muscle mass (i.e., appendicular skeletal muscle mass index), and physical function (i.e., gait speed, short physical performance battery, and timed up and go test). However, the methodological quality of the included RCTs was relatively low due to their high RoB, making it difficult to evaluate the efficacy of herbal medicine in sarcopenia. In terms of safety, several adverse events were reported. Conclusion: This review suggests that herbal medicine has a positive effect on muscle strength, muscle mass, and physical performance in elderly patients with sarcopenia, but there is a clear need for further research in this area.

경계요소법을 이용한 다중결함의 SH형 초음파 산란장 해석에 관한 연구 (A Study on Scattered Fields Analysis of Ultrasonic SH-Wave from Multi-Defects by Boundary Element Method)

  • 이준현;이서일
    • 대한기계학회논문집A
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    • 제23권11호
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    • pp.1878-1885
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    • 1999
  • Ultrasonic technique which is one of the most common nondestructive evaluation techniques has been applied to evaluate the integrity of structures by analyzing the characteristic of scattering sign al from internal defects. Therefore, a numerical analysis of ultrasonic scattering field due to defect profiles is absolutely needed for the accurate, quantitative estimation of internal defects. In this paper, the SH-wave scattering by multi-cavity defects and inclusion using Elastodynamic Boundary Element Method is studied. The effects of shape and distance of defects on transmitted and reflected fields are considered. The interaction of multi-cavity defects in SH-wave scattering is also investigated. Numerical calculations by the BEM have been carried out to predict near field solution of scattered fields of ultrasonic SH-wave. The presented results can be used to improve the detection sensitivity and pursue quantitative nondestructive evaluation for inverse problem.

Addition of an N-Terminal Poly-Glutamate Fusion Tag Improves Solubility and Production of Recombinant TAT-Cre Recombinase in Escherichia coli

  • Kim, A-Hyeon;Lee, Soohyun;Jeon, Suwon;Kim, Goon-Tae;Lee, Eun Jig;Kim, Daham;Kim, Younggyu;Park, Tae-Sik
    • Journal of Microbiology and Biotechnology
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    • 제30권1호
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    • pp.109-117
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    • 2020
  • Cre recombinase is widely used to manipulate DNA sequences for both in vitro and in vivo research. Attachment of a trans-activator of transcription (TAT) sequence to Cre allows TAT-Cre to penetrate the cell membrane, and the addition of a nuclear localization signal (NLS) helps the enzyme to translocate into the nucleus. Since the yield of recombinant TAT-Cre is limited by formation of inclusion bodies, we hypothesized that the positively charged arginine-rich TAT sequence causes the inclusion body formation, whereas its neutralization by the addition of a negatively charged sequence improves solubility of the protein. To prove this, we neutralized the positively charged TAT sequence by proximally attaching a negatively charged poly-glutamate (E12) sequence. We found that the E12 tag improved the solubility and yield of E12-TAT-NLS-Cre (E12-TAT-Cre) compared with those of TAT-NLS-Cre (TAT-Cre) when expressed in E. coli. Furthermore, the growth of cells expressing E12-TAT-Cre was increased compared with that of the cells expressing TAT-Cre. Efficacy of the purified TAT-Cre was confirmed by a recombination test on a floxed plasmid in a cell-free system and 293 FT cells. Taken together, our results suggest that attachment of the E12 sequence to TAT-Cre improves its solubility during expression in E. coli (possibly by neutralizing the ionic-charge effects of the TAT sequence) and consequently increases the yield. This method can be applied to the production of transducible proteins for research and therapeutic purposes.