• Title/Summary/Keyword: Fatigue-free

Search Result 201, Processing Time 0.03 seconds

Evaluation of ERS(Embedded Rail Track System): Design and Experiments (매립형철도궤도 시스템 성능평가)

  • Park, Jeung-Geun;Kim, Sun-Cheol;Han, Jong-Mon
    • Proceedings of the KSR Conference
    • /
    • 2008.06a
    • /
    • pp.1662-1671
    • /
    • 2008
  • The ERS(Embedded Rail Track system) is constructed in the world due to a slab track system having maintenance free, high structural safety, and deduction of noise and vibration. The ADRI-ERS is developed as Korean type. This paper shows that the design of ADRI-ERS and experiments according to DIN EN 13481-5 and Korea high speed train test guidelines. The ADRI-ERS has high structural safety in pull-out test, longitudinal resistance test, and fatigue test. The design method of ADRI-ERS is proposed by two design constants due to the result of experiments also.

  • PDF

Development of a Ultrasound Probe for 3-D Ultrasonic Imaging (3차원 의료기기용 초음파진단기 프로브 개발)

  • Park, Jong-Soo;Kim, Seong-Rae;Nam, Yoon-Su
    • Journal of Industrial Technology
    • /
    • v.25 no.A
    • /
    • pp.87-93
    • /
    • 2005
  • Three-dimensional ultrasonic probes being applied to the medical imaging can be grouped into three depending on the scanning methods, which are a mechanical type system, a free-hand system, and 2D phased arrays system. A mechanical type scanner uses a mechanically driven transducer to acquire series of 2D plane images. By integrating these images, a 3-D medical image can be constructed. A motor driving mechanism is a conventional choice for mechanically driving a transducer assembly which picks the raw ultrasonic images up. In this paper we attempt to design a 3D ultrasonic probe which has a operating mechanism of s tilting 3-D scanning. The motion of a transducer assembly of the ultrasonic probe is analytically modelled. We propose a selection procedure for the diameter of a wire rope driving the transducer assembly and the size of torsional spring which gives an initial tension to wire ropes.

  • PDF

Preparation of ferroelectric SrBi2Ta2O9 thin films deposited by multi-target sputtering

  • Hoon, Yang-Cheol;Gil, Yoon-Soon
    • Journal of Korean Vacuum Science & Technology
    • /
    • v.2 no.2
    • /
    • pp.92-96
    • /
    • 1998
  • Ferroelectric Bi-layered oxides SrBi2Ta2O9 (SBT) thin films have been deposited on Pt/Ti/SiO2/Si substrates using multi-target sputtering. Structure, composition, and electrical properties have been investigated on films. The SBT films were deposited with the various bismuth sputtering powers. The SBT films deposited with the bismuth sputtering power of 20 W have the most dense microstructure and the remanent polarization (Pr) of 9.2 ${\mu}$C/cm and the coercive field (Ec) of 43.8 kV/cm at an applied voltage of 5V. The SBT films deposited with the bismuth sputtering power of 20W showed a fatigue-free characteristics up to 1.0${\times}$1010 cycles under 5V bipolar pulse and a leakage current density of 2.0${\times}$10-8 A/$\textrm{cm}^2$ at 200 kV/cm.

  • PDF

Effects of Pinitol Supplementation and Strength Training on Anaerobic Performance and Status of Energy Substrates in Healthy Young Men

  • Lee, Dae-Taek;Lee, Woon-Yong
    • Nutritional Sciences
    • /
    • v.8 no.3
    • /
    • pp.189-195
    • /
    • 2005
  • To assess the effect of pinitol supplementation and strength training for two weeks on the anaerobic capacity during and after exercise, and improvement of glucose metabolism during the recovery period of muscular fatigue with repeated acute bouts of cycling exercise, a total of 24 healthy young men were recruited and randomly and equally divided into three groups; pinitol supplementation group (PSG), placebo group (PLG), and control group (CON). Using a randomized double-blinded design, subjects in PSG were provided pinitol supplement, consumed orally 1.2 g/day, and participated in the resistance exercise program and cycling exercise for two weeks. Subjects in PLG underwent the same protocol as those in PSG but consumed the same amount of placebo. No supplementation and exercise program was given to CON. Before and after the intervention, all subjects were tested for their anaerobic capacities evaluated by Wingate test twice separated by 30 min. During the test, peak anaerobic power (PP), mean anaerobic power, total work, and fatigue index were evaluated During resting and recovery, blood samples were drawn and plasma pinitol, myo-inositol, chiro-inositol, insulin, free fatty acid, glucose, and lactate levels were analyzed After two weeks, PP and relative PP of the second biking were improved from the first biking in PSG only (p<0.05). No changes were found in all other variables of Wingate test in all groups. No statistical differences between groups and pre- and post-intervention were observed in concentrations of pinitol, myo-inositol, and chiro-inositol, but pinitol concentration was higher during recovery compared to the baseline in all groups and testings (p<0.05). Lactate level during recovery was higher than the resting level, but no other blood parameters were significantly changed. In conclusion, two weeks of pinitol supplementation in conjunction with short duration of anaerobic training in healthy young men did not induce any obvious benefits in terms of anaerobic capacity and energy metabolism Individual and/or population susceptibility may be one factor responsible for adopting pinitol supplementation.

Comparison of Heart Rate Variability(HRV) in Pregnant Woman and Non-pregnant Woman (임신 여성과 가임기 여성의 심박변이도(HRV) 비교)

  • Kim, Su-min;Ye, Soo-Young
    • Journal of the Korean Society of Radiology
    • /
    • v.15 no.4
    • /
    • pp.499-505
    • /
    • 2021
  • In this study, HRV signals are analyzed to compare the autonomic nervous system activity of non-pregnant women and pregnant women. 99 disease-free pregnant women and 27 non-pregnant women from W Hospital participated in the study. The acquired HRV signals were used by the program to perform time domain analysis and frequency domain analysis. The measured values were statistically analyzed for differences between pregnancy periods through a one-way ANOVA. In the results, SDNN and RMSSD in time domain analysis had significantly higher results in early pregnancy and non-pregnant women compared to mid- and late pregnancy. In frequency domain analysis, LF and HF had significantly higher values for pregnancy and non-pregnancy compared to midand late-term, but there was no significant difference between VLF and LF/HF. his means that as pregnancy progresses, the ability to control autonomous nerves decreases in the middle and late stages of pregnancy and increases physical fatigue and mental fatigue. Therefore, the longer the pregnancy period, the more special care is needed to maintain mental and physical stability of pregnant women.

The Evaluation of Structural Safety of Impeller Using FEM Simulation (FEM 시뮬레이션을 이용한 임펠러의 구조 안전성 평가)

  • Jung, Jong Yun
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.43 no.4
    • /
    • pp.41-47
    • /
    • 2020
  • As modern industries are highly being developed, it is required that mechanical parts have to be manufactured with a high precision. In order to have precise parts, error-free designs have to be done before manufacturing with accuracy. For this intention being fulfilled, a mechanical analysis is essential for design proof. Nowadays, FEM simulation is a popular tool for verifying a machine design. In this paper, an impeller, being utilized in a compressor or an oil mixer as an actuator, is studied for an evaluation. The purpose of this study is to present a safety of an impeller for a proof of its mechanical stability. A static analysis for stress, strain, and deformation within a regular usage is examined. This simulation test shows 357.26×106 Pa for maximum equivalent stress and 0.207mm for total deformation. A fatigue test is carried to provide durability and its result shows that minimum safety factor is 3.2889, which guarantees that it runs without a fatigue failure in 106 cycles. The natural frequencies for the impeller is ranged from 228.09Hz to 1,253.6Hz for the 1st to the 6th mode. Total deformations at these natural frequencies are shown from 6.84mm to 12.631mm. Furthermore, Campbell diagram reveals that a critical speed is not found throughout regular rotational speeds. From the test results for the analysis, this paper concludes that the suggested impeller is proved for its mechanical safety and good to utilize at industries.

Characterization of Ferroelectric $SrBi_2Ta_2O_9$ Thin Films Deposited by RF Magnetron Sputtering With Various Annealing Temperatures (RF magnetron sputtering으로 제조된 강 유전체 $SrBi_2Ta_2O_9$ 박막의 열처리 온도에 따른 특성 연구)

  • 박상식;양철훈;윤순길;안준형;김호기
    • Journal of the Korean Ceramic Society
    • /
    • v.34 no.2
    • /
    • pp.202-208
    • /
    • 1997
  • Bi-layered SrBi2Ta2O9(SBT) films were deposited on Pt/Ti/SiO2/Si sibstrates by rf magnetron sputt-ering at room temperature and then were annealed at 75$0^{\circ}C$, 80$0^{\circ}C$ and 85$0^{\circ}C$ for 1 hour in oxygen at-mosphere. The film composition of SrBi2Ta2O9 was obtained after depositing at room temperature and annealing at 80$0^{\circ}C$. Excess 20mole% Bi2O3 and 30 mole% SrCO3 were added to the target to compensate for the lack of Bi and Sr in SBT film. 200 nm thick SBT film exhibited and dense microstructure, adielectric constant of 210, and a dissipation factor of 0.05 at 1 MHz frequency. The films exhibited Curie temperature of 32$0^{\circ}C$ and a dielectric constant of 314 at that temperature under 100 kHz frequency. The remanent polarization(2Pr) and the coercive field(2Ec) of the SBT films were 9.1 $\mu$C/$\textrm{cm}^2$ and 85 kV/cm at an applied voltage of 3V, resspectively and the SBT film showed a fatigue-free characteristics up to 1010 cy-cles under 5V bipolar pulse. The leakage current density of the SBT film was about 7$\times$10-7A/$\textrm{cm}^2$ at 150 kV/cm. Fatigue-free SBT films prepared by rf magnetron sputtering can be suitable for application to non-volatile memory device.

  • PDF

Effect of 12 Hours Fasting Resistance Exercise on Metabolic Efficiency and Fatigue in Convergence Ages (융복합 시대의 12시간 공복저항운동이 대사효율성 및 피로물질에 미치는 영향)

  • Baek, Soon-Gi
    • Journal of Digital Convergence
    • /
    • v.14 no.9
    • /
    • pp.471-478
    • /
    • 2016
  • The purpose of this study to examine the effect of 12 hours fasting resistance exercise on metabolic efficiency and fatigue of middle-aged female for 8 weeks. 50 middle-aged female target group pre-test exercise group(EX) and the control over the homogeneity in the control group(CON) were selected for this purpose divided into two groups. Exercise group(EX) is maintained after 8 weeks four times weeks 12 hours fasting resistance was performed for 60 minutes, the control group(CON) were compared to a normal life with the group of the exercise group(EX). Resistance applied to the exercise group(EX) were using free weights and a fixed mechanism applied around the upper and lower body exercise program for heart muscle, exercise intensity based on the 70% 1RM until 4 weeks, 5-8, which was performed by the aid program set to 80%. Through this procedure were as follows. First, 12 hours fasting resistance exercise showed the significance of the interaction effect in metabolic efficiency, blood pressure(SBP, DBP), fat, fasting glucose, fasting insulin(p<.01). Second, 12 hours fasting resistance exercise showed the significance of the interaction effect in the treatment program in which lactic acid, uric acid(p<.01).

An Analysis of the Gyungokgo's Ingredients and a Comparison Study on Anti-oxidation Effects According to the Kinds of Extract (경옥고(瓊玉膏)의 성분 분석 및 추출물별 항산화(抗酸化) 효능 비교)

  • Lee, So-Yeon;Shin, Yoo-Jeong;Park, Jong-Hyuk;Kim, Seung-Mo;Park, Chi-Sang
    • The Korea Journal of Herbology
    • /
    • v.23 no.2
    • /
    • pp.123-136
    • /
    • 2008
  • Objectives : To estimate the value of the Gyungokgo as therapeutic agent preventing against aging with an analysis of the ingredients and the bio-activating effects by enzymologic methods. Methods : A quantitative analysis of general ingredients' of the Gyungokgo's extract was done first. The effects on electronic donating ability, SOD-like activity, nitric oxide inhibition, xanthine oxidase inhibition, whitening effect have been investigated in the physiological activity measurement of function experiment. Results : The contained hydrolyzed amino acid is Valine, Aspartic acid, Arginine, Isoleucine and the contained free amino acid is Arginine, Phenylalanine, Valine, Glycine. The derivative of free amino acid is Phosphoserine, Carnocine, ${\gammer}$-Aminoisobutyric acid. And the Gyungokgo contains 14 species of minerals, K>Na>Ca>Mg>Fe>Al>Mn. Then, to assure of the Gyungokgo's anti-oxidation, these following subjects -polyphenol, electronic donating ability, SOD-like activity, nitric oxide inhibition, xanthine oxidase inhibition, tyrosinase inhibation- are analyzed and show high activity especially the most in chloroform extracts, (every ingredients written by the order of high amount) Conclusions : The Gyungokgo contains many materials functioning as anti-oxidation, neurotransmitter, anti-fatigue and immune agent.

  • PDF

Efficacy and Toxicity of Sunitinib in Metastatic Renal Cell Carcinoma Patients in Egypt

  • Edesa, Wael Abdelgawad;Abdelmalek, Raafat Ragaey
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.5
    • /
    • pp.1971-1976
    • /
    • 2015
  • Background: To evaluate our results in terms of response, survival and toxicity profile of sunitinib among Egyptian patients with metastatic renal cell carcinoma. Materials and Methods: Between January 2010 and December 2013, 44 patients with metastatic renal cell carcinoma who received sunitinib at an oncology center of Cairo university hospitals were enrolled in this retrospective analysis. Results: The median age of the patients was 53 years, 22 (50%) having localized disease at presentation, while the remaining half of the patients presented with metastasis. At a median follow up of 19 months, 9 (21%) patients achieved partial remission, while disease was reported stable in 20 cases (45%) and progressive in 7 (16%), 4 (9%) being lost to follow up, and 4 (9%) had discontinued therapy due to toxicity. The median overall survival was 23 months (95%CI 15.2 - 30.9), while progression free survival was 12 months (95%CI 11.6 - 12.3). The most commonly reported non hematological grade 3 adverse events included mucositis (15.9%), hand-foot syndrome (13.6%), and fatigue (9%), while the predominant grade 3 or 4 laboratory abnormalities were neutropenia (6.8%), followed by anemia in 4.5% of patients. Conclusions: Our efficacy data were comparable to the published literature in terms of progression free survival and overall survival, while toxicity profile is different from Asian and western countries. However, sunitinib adverse events were manageable and tolerable in most of our Egyptian patients.