• 제목/요약/키워드: Equal Load

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Descriptive Study on Selected Risk Factors and Histopathology of Breast Carcinoma in a Tertiary Care Centre in Kerala, India with Special Reference to Women Under 40 Years Old

  • Varughese, Ashley Ann;Poothiode, Usha;Manjula, V.D.
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권1호
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    • pp.181-184
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    • 2015
  • Background: Breast cancer is the most common female cancer in Kerala, South India, with the incidence increasing in the past two decades, also in young women. However, there are limited data regarding the burden of disease, its epidemiology and histopathological characteristics in the state. Materials and Methods: This desciptive study covered 303 breast cancers evaluated during the period of December 2011 to August 2013 in the Department of Pathology, Government Medical College, Kottayam.The patients were also interviewed regarding selected risk factors. Results: The majority of the cases were 41-60 years of age with a mean at presentation of 53 years. Infiltrating ductal carcinoma was the most common subtype, followed by pure mucinous carcinoma and then lobular carcinoma. Of the cases, 6.6% were nullipara and 52.8% had fewer than or equal to 2 children. Median age at first child birth was 23 years (national value-19.8 years). A significant proportion (15%) had family history of breast cancer. Some 13.5%(41 cases) comprised the young breast cancer group (${\leq}40$years) with a mean age at first child birth in them was 27.4 years, 5 being nullipara and 6 having a positive family history. Conclusions: Breast cancer awareness, better availability of screening techniques and identification and targeting high risk groups all help to tackle the increasing load of breast carcinoma. A good proportion of cases comprised the young breast cancer group (under 40). Younger women should thus also be educated about breast carcinoma-risk factors, symptoms and diagnostic techniques to help in early detection and effective approach esto treatment.

A study on the creep mechanism of Al 7075 alloy (Al 7075 합금 의 크리이프 변형 기구 에 관한 연구)

  • 백남주;강대민;백성관
    • Transactions of the Korean Society of Mechanical Engineers
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    • 제9권4호
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    • pp.395-402
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    • 1985
  • The apparent activation energy Q$_{c}$ and the applied stress exponent n have been determined during creep of Al 7075 alloy over the temperature range of 90.deg. C to 320.deg. C (0.4-0.65T$_{m}$) and stress range of 1.85 kgf/mm$^{2}$ to 21 kgf/mm$^{2}$, respectively in order to investigate the creep behavior. Constant load creep tests were carried out in the experiment. At round the temperature of 200.deg. C-240.deg. C and under the stress level 8.13-9.55kgf/mm$^{2}$ and again at around the temperature of 280.deg. C-320.deg. C and under the stress level of 1.85-2.55kgf/mm$^{2}$, the creep behavior obeyed for the creep deformation was nearly equal to that of the volume self diffusion of pure aluminum (34kcal/mole). But at around the temperature of 90.deg. C and under the stress level of 10-21kgf/mm$^{2}$, the creep behavior did not obey a simple power-law relation and the apparent activation enrgy, Q$_{c}$ was 26.01 kcal/mole. From the above facts, at around the temperature of 200.deg. C-240.deg. C and 280.deg. C-320.deg. C, the creep deformation for Al 7075 alloy seemed to be controlled by dislocation climb but at 90.deg. C, by cross slip over the range of experimental stress conditions.tions.

Development and Performance Experiment of Iso-tensioning System using Electrical Resistance Loadcell (전기저항식 로드셀을 이용한 균등긴장시스템 개발 및 성능실험)

  • Park, Won-Tae;Chun, Kyoung-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제17권2호
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    • pp.220-226
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    • 2016
  • Because MS(Multi-Strand) cables consist of many strands, a jacking force is applied to each strand one by one for cable construction. All strands should have an equal tensile force when the last one is wedged. This is the core technology for MS iso-tensioning. In this study, a new MS cable iso-tensioning system was developed for controlling and jacking the high-strength strands, with an ultimate tensile strength of 2,200MPa, for a stay cable of extra-dosed/cable-stayed bridges. The newly developed iso-tensioning system consists of electrical resistance load cells, hydraulic jacking devices, hydraulic pumps, and integrated controllers. Moreover, it is embedded with an algorithm that can control and predict the variations in tensile forces of the Master and Slave strands in real time. Actual experiments were carried out to verify the function and performance of the newly developed system. This system was applied successfully to the stay cable construction of 2nd Tae-in extra-dosed bridge in Gwangyang.

A Study of Carbon NCF Prepreg Manufacturing and Stacking Pattern Optimal Design Using Structure Analysis (CFRP 적용을 위한 Carbon NCF Prepreg 제작 및 구조해석을 활용한 적층패턴 최적설계 연구)

  • Kim, S.;Shin, H.C.;Ha, Sung Kyu
    • Composites Research
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    • 제33권1호
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    • pp.13-18
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    • 2020
  • Recently, the fire rescue truck in problem proceed research it for the fast works action and for pass the small road. So we were research for weight reduction. In this study, the (NO. 5) fifth boom of the fire rescue truck have 288 mm(W) × 299 mm(D) × 3,691 mm(L) with a maximum load of 876 kg and the thickness of 3 mm of the Steel Boom. This changing of Steel (STRENX960) to CFRP was weave Carbon Fiber NCF (±45°, 2axis) and then it make the NCF Prepreg. This process was designed based on structural analysis, the effects of NCF Prepreg (±45°) on torsion were identified, and the optimal design was made with Stacking Pattern (b). Stack patterns were optimized for levels equal or higher than existing Steel Boom and CFRP Boom stacked in the UD direction, and finally, the lightening effect on weight of approximately 49.6% of the steel was identified.

Effect of power resistance intervention on fitness and muscle mass and short physical performance battery in older women adults (파워 저항운동이 여성노인의 체력, 근육량 및 단기운동수행력에 미치는 영향)

  • Oh, Yoo-Sung;Park, Woo-Young
    • Journal of the Korean Applied Science and Technology
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    • 제37권1호
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    • pp.114-123
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    • 2020
  • The present study aimed the effects of power resistance training(PRT) on fitness, muscle mass and short physical performance battery(SPPB) elderly women. Thirty older woman(aged 70 over years) were divided in two groups : PRT(n=15) and traditional resistance training(TRT)(n=15). The volunteers trained three times a week, during 12weeks. Both groups performed an equal work output with load red color thera-band. Three sets of twelve repetitions of each exercise were performed with rest intervals of 60s between sets. According to the results. Main fitness were significantly difference in grip strength(TRT) and cardiopulmonary. Muscle was not significantly difference. And Timed up and go and 400m walking(TRT) were significantly difference. There is sufficient effects on between training method in fitness, SPPB but PRT training may yield better results compared with TRT.

A Study on the Characteristics of High Temperature and Mechanisms for Creep Deformation of AZ31 Mg Alloy (AZ31마그네슘 합금의 고온특성 및 크리이프 변형기구에 관한연구)

  • Kang, D.M.;An, J.O.
    • Journal of Power System Engineering
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    • 제9권4호
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    • pp.96-101
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    • 2005
  • Magnesium alloys have been widely used for many structural components of automobiles and aircraft because of high specific strength and good cast ability in spite of hexagonal closed-packed crystal structure of pure magnesium. In this study, uniaxial tension tests at high temperature and creep tests are done in order to investigate the characteristics of high temperature and mechanisms for creep deformation of AZ31 Mg alloy. Yield stress and ultimate tensile stress decreased with increasing temperature, but elongation increased from results of uniaxial tension test at high temperature. The apparent activation energy Qc, the applied stress exponent n and rupture life have been determined during creep of AZ31 Mg alloy over the temperature range of 473K to 573K and stress range of 23.42 MPa to 93.59 MPa, respectively, in order to investigate the creep behavior. Constant load creep tests were carried out in the equipment including automatic temperature controller, whose data are sent to computer. At around the temperature of $473K{\sim}493K$ and under the stress level of $62.43{\sim}93.59%MPa$, and again at around the temperature of $553K{\sim}573K$ and under the stress level of $23.42{\sim}39.00MPa$, the creep behavior obeyed a simple power-law relating steady state creep rate to applied stress and the activation energy for the creep deformation was nearly equal, respectively, and a little low to that of the self diffusion of Mg alloy including aluminum. Also rupture surfaces at high temperature have had bigger dimples than those at lower temperature by SEM.

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The Effect of the Weight of a Backpack on Craniovertebral Angle and Neck Muscle Activities on Some University Students (백팩 무게가 일부 대학생의 머리척추각과 목 근활성도에 미치는 영향)

  • Park, Cheon-jun;An, Duk-hyun
    • Physical Therapy Korea
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    • 제27권1호
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    • pp.45-52
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    • 2020
  • Background: A backpack is available equipment for moving some objects. Most studies have found that the appropriate weight limit of backpack for students is between 10% to 15% of their body weight (BW). However, Some students should carry a backpack heavier than 15% of BW. Therefore, It is associated with abnormal shoulder and neck posture on students. Objects: This study tested the effects that various amounts of weight carried by university students in their backpacks had on their cervical posture and electromyography of neck muscle. Methods: The subjects consisted of 12 students (6 male, 6 female) in university. There were three loading conditions tested: no backpack, a backpack that weighed 10% and 15% of the student's BW. The dependent variables were the craniovertebral angle (tragus to C7) and the neck muscle activities (sternocleidomastoid, upper trapezius). All 12 subjects were asked to walk while wearing a backpack for 5 minutes and were then instructed to rest for 2 minutes. Results: When assessing the craniovertebral angle, the results of this study were significantly decreased in the order of 0%, 10%, and 15%. And then, there were significantly increased electromyography of neck muscles that comparison of the weight of 10% and 15% on 0%. It was found that as the weight of the backpack increased, the craniovertebral angle decreased (p < 0.05) and the muscle activities increased (upper trapezius p = 0.012, sternocleidomastoid p = 0.013). Conclusion: Our study recommended that some students shouldn't carry on over the 15% backpack of own weight, and also they should distribute backpack load to equal on body for optimal posture.

Brazilian Test of Concrete Specimens Subjected to Different Loading Geometries: Review and New Insights

  • Garcia, Victor J.;Marquez, Carmen O.;Zuniga-Suarez, Alonso R.;Zuniga-Torres, Berenice C.;Villalta-Granda, Luis J.
    • International Journal of Concrete Structures and Materials
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    • 제11권2호
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    • pp.343-363
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    • 2017
  • The objective of this work was finding out the most advisable testing conditions for an effective and robust characterization of the tensile strength (TS) of concrete disks. The independent variables were the loading geometry, the angle subtended by the contact area, disk diameter and thickness, maximum aggregate size, and the sample compression strength (CS). The effect of the independent variables was studied in a three groups of experiments using a factorial design with two levels and four factors. The likeliest location where failure beginning was calculated using the equations that account for the stress-strain field developed within the disk. The theoretical outcome shows that for failure beginning at the geometric center of the sample, it is necessary for the contact angle in the loading setup to be larger than or equal to a threshold value. Nevertheless, the measured indirect tensile strength must be adjusted to get a close estimate of the uniaxial TS of the material. The correction depends on the loading geometry, and we got their mathematical expression and cross-validated them with the reported in the literature. The experimental results show that a loading geometry with a curved contact area, uniform load distribution over the contact area, loads projected parallel to one another within the disk, and a contact angle bigger of $12^{\circ}$ is the most advisable and robust setup for implementation of BT on concrete disks. This work provides a description of the BT carries on concrete disks and put forward a characterization technique to study costly samples of cement based material that have been enabled to display new and improved properties with nanomaterials.

Effects of Cover Thickness on Confining Transverse Reinforcement of RC Bridge Columns (철근콘크리트 교각 심부구속 횡방향철근량 산정식의 피복두께 영향)

  • Son, Hyeok-Soo;Lee, Jae-Hoon;Suh, Suk-Koo;Oh, Myung-Seok;Yoon, Cheol-Kyun
    • Proceedings of the Korea Concrete Institute Conference
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    • 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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    • pp.81-84
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    • 2008
  • The equation, specified in current bridge design code, for calculating the confining transverse reinforcement amount of RC bridge columns has been made to provide additional load-carrying strength for concentrically loaded columns equal to or slightly greater than the strength lost when the cover concrete spalls off. However, this equation does not directly consider ductile behavior, which is an important factor for the seismic behavior of bridge columns. Consequently, if the section area is relatively small or if the section area ratio becomes excessively large due to the concrete cover thickness increased for durability, too large an amount of transverse reinforcement, which could deteriorate the constructability and economy of piers, will be required. This study intends to analyze what effects the concrete cover thickness has on the equation for determining the confining transverse reinforcement amount.

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An Active Voltage Doubling Rectifier with Unbalanced-Biased Comparators for Piezoelectric Energy Harvesters

  • Liu, Lianxi;Mu, Junchao;Yuan, Wenzhi;Tu, Wei;Zhu, Zhangming;Yang, Yintang
    • Journal of Power Electronics
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    • 제16권3호
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    • pp.1226-1235
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    • 2016
  • For wearable health monitoring systems, a fundamental problem is the limited space for storing energy, which can be translated into a short operational life. In this paper, a highly efficient active voltage doubling rectifier with a wide input range for micro-piezoelectric energy harvesting systems is proposed. To obtain a higher output voltage, the Dickson charge pump topology is chosen in this design. By replacing the passive diodes with unbalanced-biased comparator-controlled active counterparts, the proposed rectifier minimizes the voltage losses along the conduction path and solves the reverse leakage problem caused by conventional comparator-controlled active diodes. To improve the rectifier input voltage sensitivity and decrease the minimum operational input voltage, two low power common-gate comparators are introduced in the proposed design. To keep the comparator from oscillating, a positive feedback loop formed by the capacitor C is added to it. Based on the SMIC 0.18-μm standard CMOS process, the proposed rectifier is simulated and implemented. The area of the whole chip is 0.91×0.97 mm2, while the rectifier core occupies only 13% of this area. The measured results show that the proposed rectifier can operate properly with input amplitudes ranging from 0.2 to 1.0V and with frequencies ranging from 20 to 3000 Hz. The proposed rectifier can achieve a 92.5% power conversion efficiency (PCE) with input amplitudes equal to 0.6 V at 200 Hz. The voltage conversion efficiency (VCE) is around 93% for input amplitudes greater than 0.3 V and load resistances larger than 20kΩ.