• Title/Summary/Keyword: On Resistance

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Effects of Lower Extremity Resistance Exercise Using Elastic Bands on Balance in Elderly People

  • Kim, Nyeon Jun;Kim, Moo Ki
    • Journal of International Academy of Physical Therapy Research
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    • v.3 no.2
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    • pp.440-445
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    • 2012
  • The purpose of this study was to assess the effects of lower extremity resistance training using elastic bands on balance in elderly people. Eight elderly persons each were randomly assigned to a test group(resistance exercise group, REG) or a control group(CG). FRT and TUG test were used to compare balance before and after exercise. Exercise programs were implemented three times a week for 40 minutes for nine weeks. They did warm-up exercise for 5 minutes and then lower extremity resistance exercise using elastic bands for 30 minutes. And then they did cool-down exercise for 5 minutes. TUG and FRT significantly decreased but in the control group it did not significantly decrease. In comparison between the groups, TUG and FRT significantly reduced in the resistance exercise group compared to the control group. Lower extremity resistance training using elastic bands performed by elderly persons are considered to be effective in improving balance.

Experimental study on the hydrophilic performance of pre-coated aluminum foil (알루미늄 호일의 친수코팅 성능 개선에 관한 실험적 연구)

  • 김영생;길용현;박환영;윤백;김자수소;김병열
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.11 no.6
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    • pp.725-732
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    • 1999
  • It is usual to use hydrophilic-coated aluminum foil for evaporator fin of air-conditioners to reduce air flow resistance caused by the water droplets condensed on the fin surface. The major effect of a hydrophilic coating is to reduce the contact angle of the condensate and prevent bridging of the condensate between the adjacent fins. The performance of hydrophilic coating generally tends to be degraded as it is used since the coating material is washed down by the condensate. In the present work, several types of hydrophilic coatings were evaluated in terms of durability of hydrophilicity, corrosion resistance and heat resistance. Results showed that an improved hydrophilic coating of resin type presented superb qualify in terms of durability and corrosion resistance while having almost the same level of qualify in heat resistance compared with the others.

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Study on Filtration Characteristics of Wood Pulp and Non-Wood Fiber (목재펄프 및 비목재 섬유의 여과제 특성에 관한 연구)

  • Cho, Jun-Hyung;Han, James S.;Lee, Beom-Goo
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.4
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    • pp.86-91
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    • 1998
  • The drainage was used to determine the specific filtration resistance for wood and non-wood fibers. The drainage rate is also affected by factors that can be changed on consistency, pressure drop across the mat, basis weight, additives, and viscosity. Recent development of theoretical studies in flow through porous media and filtration operation emphasize the urgent need for more accurate data for porosity and specific filtration resistance. This study was investigated to determine specific filtration resistance of Hw, Sw-BKP and Kenaf fiber by filtration experimental. Freeness levels selected were 150,250,and $350m\ell$ CSF. The average specific filtration resistance decreased as freeness increased and resistance of Sw-BKP was greater than that of Hw-BKP. The filtrate and porosity increased and specific filtration resistance decreased as particle size of fiber increased.

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Experimental and numerical study on ice resistance for icebreaking vessels

  • Hu, Jian;Zhou, Li
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.3
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    • pp.626-639
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    • 2015
  • Ice resistance is defined as the time average of all longitudinal forces due to ice acting on the ship. Estimation of ship's resistance in ice-covered waters is very important to both designers and shipbuilders since it is closely related to propulsion of a ship and it determines the engine power of the ship. Good ice performance requires ice resistance should be as low as possible to allow different manoeuvres. In this paper, different numerical methods are presented to calculate ice resistance, including semi-analytical method and empirical methods. A model test of an icebreaking vessel that was done in an ice basin has been introduced for going straight ahead in level ice at low speed. Then the comparison between model test results and numerical results are made. Some discussions and suggestions are presented as well to provide an insight into icebreaking vessel design at early stage.

Corrosion Resistance of the Roll Formed Steel Bolts with the Various Types of Coating Methods (1) (다양한 코팅 방법에 따른 전조한 강 볼트의 내부식성 (1))

  • Mamatov, S.;Hamrakulov, B.;Son, Y.H.;Kim, I.
    • Transactions of Materials Processing
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    • v.28 no.2
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    • pp.71-76
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    • 2019
  • Corrosion resistance is one of the essential properties required in steel bolts. The various types of coatings are used to improve the corrosion resistance of steel bolts. But, roll formed, subsequently Zn alloy electrodeposited and top coated steel bolt easily takes place the white storage stain or white rust under high humidity condition. To investigate the corrosion resistance of roll formed and subsequently the various types of coated steel bolts, their polarization curves were measured by potentio-dynamic tester in this study. Based on the measured polarization curves, the more times of chromate and top coating on roll formed steel bolt, the higher corrosion resistance was shown. The roll formed steel bolt, which was Zn-Ni electro-deposited, two times chromated, one time inorganic top coated, one time organic top coated and annealed, showed the best corrosion resistance.

Mechanisms and Control Strategies of Antibiotic Resistance in Pathological Biofilms

  • Luo, Ying;Yang, Qianqian;Zhang, Dan;Yan, Wei
    • Journal of Microbiology and Biotechnology
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    • v.31 no.1
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    • pp.1-7
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    • 2021
  • Bacterial biofilm is a community of bacteria that are embedded and structured in a self-secreted extracellular matrix. An important clinical-related characteristic of bacterial biofilms is that they are much more resistant to antimicrobial agents than the planktonic cells (up to 1,000 times), which is one of the main causes of antibiotic resistance in clinics. Therefore, infections caused by biofilms are notoriously difficult to eradicate, such as lung infection caused by Pseudomonas aeruginosa in cystic fibrosis patients. Understanding the resistance mechanisms of biofilms will provide direct insights into how we overcome such resistance. In this review, we summarize the characteristics of biofilms and chronic infections associated with bacterial biofilms. We examine the current understanding and research progress on the major mechanisms of antibiotic resistance in biofilms, including quorum sensing. We also discuss the potential strategies that may overcome biofilm-related antibiotic resistance, focusing on targeting biofilm EPSs, blocking quorum sensing signaling, and using recombinant phages.

Analytical model for flexural and shear strength of normal and high-strength concrete beams

  • Campione, Giuseppe
    • Structural Engineering and Mechanics
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    • v.78 no.2
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    • pp.199-207
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    • 2021
  • In the present paper, an analytical model is proposed to determine the flexural and shear strength of normal and high-strength reinforced concrete beams with longitudinal bars, in the presence of transverse stirrups. The model is based on evaluation of the resistance contribution due to beam and arch actions including interaction with stirrups. For the resistance contribution of the main bars in tension the residual bond adherence of steel bars, including the effect of stirrups and the crack spacing of R.C. beams, is considered. The compressive strength of the compressed arch is also verified by taking into account the biaxial state of stresses. The model was verified on the basis of experimental data available in the literature and it is able to include the following variables in the resistance provision: - geometrical percentage of steel bars; - depth-to-shear span ratio; - resistance of materials; - crack spacing; - tensile stress in main bars; - residual bond resistance including the presence of stirrups;- size effects. Finally, some of the more recent analytical expressions able to predict shear and flexural resistance of concrete beams are mentioned and a comparison is made with experimental data.

A study on Improving the Level of Introduction of Smart Factories Using the Extended Innovation Resistance Model (확장된 혁신저항모델을 활용한 스마트 팩토리 도입 수준 제고에 대한 연구)

  • Park, Chan-Kwon
    • Journal of Convergence for Information Technology
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    • v.11 no.3
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    • pp.107-124
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    • 2021
  • This study is a study on the innovation resistance that may arise in connection with the introduction and use of smart factory-related technologies by SMEs. It is to study the effect of the leading factors of innovation resistance on innovation resistance and the effect of innovation resistance on use intention by using the extended innovation resistance model. A total of 176 survey data were used for the study, and the study was conducted using SPSS 25 and Smart PLS 2.0. Relative advantage, suitability, perceived risk, social impact, and organizational characteristics have a significant effect on innovation resistance, and innovation resistance was tested to have a significant effect on the intention to use. As an implication according to the research, a plan to improve the level of introduction and use of smart factories using the expanded innovative storage model was presented by dividing positive and negative factors, and factors that should be improved and factors that should be reduced are presented. It was specifically presented.

Molecular Breeding for Plant Disease Resistance : Prospects and Problems

  • Park, Hyo-Guen
    • The Plant Pathology Journal
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    • v.17 no.1
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    • pp.1-8
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    • 2001
  • The technique of plant transformation has started to show off its great power in the area of plant breeding by commercially successful introduction of transgenic varieties such as herbicide tolerant soybean and insect resistant corn in USA with an unimaginable speed. However, in contrast with the great success in the commercialization of herbicide tolerance and insect resistance, the transformation works on disease resistance has not yet reached the stage of full commercialization. This review surveys the current status of molecular breeding for plant disease resistance and their limits and problems. Some novel ideas and approaches in molecular breeding for disease resistance are introduced.

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A study on the bottom trawl gear by the trial of a stern trawler-I -On the Resistance of bottom trawl gear- (실선 시험에 의한 저층 트롤 어구에 관한 연구-I -어구의 저항에 관하여-)

  • 조봉곤;조성옥
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.36 no.4
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    • pp.274-280
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    • 2000
  • To analyze the resistance of the bottom trawl which is composed with 6 seams net, the field experiment was carried out on the sea near Kokunsan Is., western sea of Korea. The resistance was respectively measured in the otter board and the net according to the change of warp length and towing speed. The results obtained are summarized as follows : 1. Total resistance of the test trawl gear are slightly increased according to the length of warp. 2. The resistance of net is increasing a little according to the length of warp, but it is expressed. $$ R_n/=10 \frac{d}{\ell}$representatively. 3. The resistance of otter board can be expressed $Rb=1810_{\upsilon}^0.8.$ 4. Comparing with the value of measuring resistance and Koyama formula resistance by the length of warp respectively, the resistance of test trawl gear is high in the slow towing speed, and the resistance of Koyama formula is high in the fast towing speed, and that the cross-point of the both line between the resistance of the test net and Koyama formula is moved to high according to the increment of warp length.

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