• Title/Summary/Keyword: Controlled Rolling

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Development of Multi-Action Die for the Forming Process of Serrated Sheets (판재의 돌기성형을 위한 공정 개발에 관한 연구)

  • Koo, H.S.;Min, K.H.;Seo, J.M.;Noh, J.H.;Vishara, R.J.;Hwang, B.B.
    • Transactions of Materials Processing
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    • v.17 no.1
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    • pp.59-67
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    • 2008
  • This paper is concerned with the development of multi-action die or multiple sliding die for the forming process of serrated sheets. Serrated sheets is used as a toothed or serrated seal for securing together overlapping portions of steel or plastic strapping ligature and have been produced conventionally in several methods such as rolling and indentation. Recently, longitudinally oriented thermoplastic materials have been widely used in the strapping industry, while such materials are quite slippery. Provided projections on a seal biting into the strap should overcome the slipperiness and also the tooth configuration must be closely controlled to avoid too much transverse penetration of the strap which could result in the shredding of the strap when it is placed under tension. The seal includes a central portion with a plurality of teeth which bite into one strap portion and a pair of reversely bent legs with a plurality of teeth which bite into the other strap portion. Forming processes applicable for serrated sheets have reviewed in qualitative sense to find possibility in terms of applicability of one of existing processes to the serrated sheet forming process. Existing seal products have been analyzed with enlarged picture of strap contacting surface of the seal by microscope. Based on the analyses of the existing forming processes and seal products, a new forming process is proposed for serrated sheets. The proposed process requires a multislide die which enables inclined indentation or cut-in into the seal material as well as scratching processes sequentially in a single action press.

Effects of functional training on strength, function level, and quality of life of persons in intensive care units

  • Seo, Byul;Shin, Won-Seob
    • Physical Therapy Rehabilitation Science
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    • v.8 no.3
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    • pp.134-140
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    • 2019
  • Objective: The purpose of this study was to investigate the effect of exercise therapy and bedside ergometer exercise on muscle strength, function level, and quality of life of persons in intensive care. Design: Randomized Controlled Trial Methods: Sixteen patients in the ICU were randomly assigned to either the exercise group (n=8) or the bedside cycle ergometer group (n=8). Activities in the ICU exercise group (rolling, sitting at the edge of the bed, transfer from sitting to standing, standing balance training, ambulation) and bedside cycle ergometer group were performed 5 times a week for 30 minutes during the ICU admission period. Medical Research Council (MRC) and Functional Status Scale-Intensive Care Unit (FSS-ICU) parameters were assessed at the time of admission to the ICU, and reevaluation was assessed on the day of ICU discharge. The Short Form-36 (SF-36) was assessed at the time of discharge from the ICU. Results: MRC and FSS-ICU were significantly increased before and after intervention in both the experimental and control groups (p<0.05). There was a significant difference between MRC and FSS-ICU in the comparison of the changes before and after the intervention (p<0.05). SF-36 was compared between groups after intervention and there was a significant difference between the experimental and the control group (p<0.05). Conclusions: Muscle strength and functional levels improved after intervention in both the experimental and control groups. The ICU exercise group was more effective than the bedside cycle ergometer group to improve muscle strength, functional level, and quality of life performance of persons in the ICU.

Role of CopA to Regulate repABC Gene Expression on the Transcriptional Level (전사 수준에서 repABC 유전자 발현을 조절하는 CopA 단백질의 역할)

  • Sam Woong Kim;Sang Wan Gal;Won-Jae Chi;Woo Young Bang;Tae Wan Kim;In Gyu Baek;Kyu Ho Bang
    • Journal of Life Science
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    • v.34 no.2
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    • pp.86-93
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    • 2024
  • Since replication of plasmids must be strictly controlled, plasmids that generally perform rolling circle replication generally maintain a constant copy number by strictly controlling the replication initiator Rep at the transcriptional and translational levels. Plasmid pJB01 contains three orfs (copA, repB, repC or repABC) consisting of a single operon. From analysis of amino acid sequence, pJB01 CopA was homologous to the Cops, as a copy number control protein, of other plasmids. When compared with a CopG of pMV158, CopA seems to form the RHH (ribbon-helix-helix) known as a motif of generalized repressor of plasmids. The result of gel mobility shift assay (EMSA) revealed that the purified fusion CopA protein binds to the operator region of the repABC operon. To examine the functional role of CopA on transcriptional level, 3 point mutants were constructed in coding frame of copA such as CopA R16M, K26R and E50V. The repABC mRNA levels of CopA R16M, K26R and E50V mutants increased 1.84, 1.78 and 2.86 folds more than that of CopA wt, respectively. Furthermore, copy numbers owing to mutations in three copA genes also increased 1.86, 1.68 and 2.89 folds more than that of copA wt, respectively. These results suggest that CopA is the transcriptional repressor, and lowers the copy number of pJB01 by reducing repABC mRNA and then RepB, as a replication initiator.

A Study on the Stretch-flangeability of Hot-Rolled High Strength Steel with Ferrite-Bainite Duplex Microstructure (페라이트-베이나이트 복합조직 고강도 열연강판의 신장플랜지 특성에 관한 연구)

  • Cho, Yeol-Rae;Chung, Jin-Hwan;Koo, Hwang-Hoe;Kim, In-Bae
    • Korean Journal of Materials Research
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    • v.9 no.12
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    • pp.1252-1262
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    • 1999
  • The effect of microstructures on the strength-flangeability of Nb bearing hot-rolled high strength steel was investigated in order to improve the strength-flangeability of conventional TS 580MPa grades HSLA steel for the automotive wheel disc. The low temperature coiling method using 3-step controlled cooling pattern after hot rolling was effective to produce the Nb-bearing high strength steel with the polygonal ferrite and bainite duplex microstructures. It was suggested that the suppressed precipitation of grain boundary cementites and the decreased hardness difference between ferrite matrix and bainite cause the excellent stretch-flangeability of ferrite-bainite duplex microstructure steel. Therefore, the formation and propagation of microcracks were suppressed relative to the conventional HSLA steel with ferrite and pearlite microstructure. In addition, the elongation was improved as compared with that of hot-rolled steel sheets using conventional early cooling pattern because the volume fraction of polygonal ferrite was increased.

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Characteristics of Temperature, Humidity and PPF Distribution by Covering Method and Environmental Control in Double Covering Greenhouse (이중피복 온실의 피복방법과 환경조절에 따른 온습도 및 광합성유효광량자속 분포 특성)

  • Lee, Hyun-Woo;Sim, Sang-Youn;Kim, Young-Shik
    • Journal of Bio-Environment Control
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    • v.21 no.1
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    • pp.1-11
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    • 2012
  • The objective of the present study is to provide data needed to find double covering method to be able to improve environment of temperature, humidity and PPF in tomato greenhouse. The distribution charts of temperature, humidity and PPF which were measured in environment control conditions such as thermal insulation, air heating, roof ventilation and air fog cooling in conventional and air inflated double layers greenhouses were drawn and analysed. The thermal insulation effect of the air inflated greenhouse was the same as that of conventional greenhouse because the temperature between insulation curtain and roof covering material was equal in heating season. The ventilation effect of the air inflated greenhouse was superior to the conventional greenhouse. The temperature distribution in the fog cooled greenhouse was uniform and the cooling effect was about $3.5^{\circ}C$. The condensation on the roof covering surface could be controlled by removing the moisture between insulation curtain and roof covering by using humidifier. The PPF of conventional greenhouse was more decreased than the air inflated greenhouse as time went by because the transmittance of conventional greenhouse declined by dust collected on the inside plastic film owing to rolling up and down operation for ventilation.