• Title/Summary/Keyword: pinch-of

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Characteristics of Thermodynamic Performance of Heat Exchanger in Organic Rankine Cycle Depending on Pinch Temperature Difference (유기랭킨사이클에서 핀치온도차의 변화에 따른 열교환기의 열역학적 성능특성)

  • KIM, KYOUNG HOON;JUNG, YOUNG GUAN;PARK, SANG HEE
    • Transactions of the Korean hydrogen and new energy society
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    • v.26 no.6
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    • pp.590-599
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    • 2015
  • In this paper a performance analysis is carried out based on the first and second laws of thermodynamics for heat exchanger in organic Rankine cycle (ORC) for the recovery of low-temperature finite thermal energy source. In the analysis, effects of the selection of working fluid and pinch temperature difference are investigated on the performance of the heat exchanger including the effectiveness of the heat exchanger, exergy destruction, second-law efficiency, number of transfer unit (NTU), and pinch point. The temperature distribution are shown depending on the working fluids and the pinch temperature difference. The results show that the performance of the heat exchanger depends on the pinch temperature difference sensitively. As the pinch temperature increases, the exergy destruction in the evaporator increases but the effectiveness, second law efficiency and NTU decreases.

The Effect on Grip and Pinch Strength with Elbow and Wrist Angle (팔꿉관절과 손목관절 각도가 쥐는 힘과 집는 힘에 미치는 영향)

  • Lee, Hyun-Ju;Yi, Seung-Ju
    • The Journal of Korean Physical Therapy
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    • v.15 no.4
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    • pp.312-318
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    • 2003
  • The purpose of this study were to determine the effect on grip and pinch strength with elbow and wrist angle change. 112 college students, 88 males, and 24 females aged 19 to 34 years, participated in the study. A Grip and pinch strength was measured in two elbow position($0^{\circ}$ and $90^{\circ}$) and three wrist position($80^{\circ},\;0^{\circ},\;23^{\circ}$). The data were analyzed by mean and deviation, and t-test using the PC/SAS system. These results were obtained as follows; 1. There was a more strength grip and pinch power in $0^{\circ}$ than $90^{\circ}$ elbow flexion at three wrist angle. 2. There was a significant high grip and pinch strength in $23^{\circ}$ dorsiflexion among three wrist angle(p<0.01). 3. The grip and pinch strength power was measured higher in male than female every elbow and wrist angle(p<0.01).

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Comparison analysis of before and after scaling training on grip and pinch strength (스케일링 실습수업 전후 수부의 악력 및 파지력 비교분석)

  • Yoo, Ja-Hea;Lee, Min-Young;Lee, Sang Young
    • Journal of Korean society of Dental Hygiene
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    • v.13 no.1
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    • pp.114-121
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    • 2013
  • Objectives : The purpose of the research is to measure Dental Hygiene students' level of musculoskeletal pain before and after receiving scaling training which involves repetitive operations and examine effects the operations have on the students' grip and pinch strength. Methods : 15 subjects in Dental Hygiene at Y university located in Chungbuk were tested on November 2, 2011. Results : 12 students had a musculoskeletal pain before receiving scaling training. However, all the 15 students had a musculoskeletal pain after the training. Body part the largest number of the students complained of the pain on was shoulders(37.9%) followed by neck(20.8%), waist(13.9%), wrists(10.3%), then back(6.9%) before receiving the training. Then the result showed that shoulders are where the largest number of students(24.1%) felt the pain, followed by neck(17.2%), wrists and fingers(13.8%), waist(12.1%), back and lower arms(6.9%), then palms(5.2%) after the training. Visual Analogue Scale(VAS) increased to $6.35{\pm}2.09$ after receiving the training from $3.31{\pm}3.38$ and this shows statistically significant difference(p<.001). Upon inspection, average grip strength decreased to $23.23{\pm}5.79kg$ from $25.00{\pm}4.51kg$ after receiving the training and this shows statistically significant difference(p<.05). Key pinch was the strongest among the three pinch strengths followed by tripod pinch then tip pinch. Average of all the three pinch strengths showed to have statistically significant difference before and after the training(p<.05); Tip pinch from $6.53{\pm}1.36$ to $5.87{\pm}1.3$, key pinch from $13.47{\pm}2.5$ to $12.53{\pm}2.30$, and tripod pinch from $9.27{\pm}3.04$ to $8.03{\pm}2.72$. Conclusions : The result showed that scaling training has effects on Dental Hygiene students' musculoskeletal subjective symptoms and their grip and pinch strength changes after receiving the training.

A Review of Hand Function (손 기능에 관한 고찰)

  • Lee, Sun-Myung
    • Journal of Korean Physical Therapy Science
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    • v.9 no.4
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    • pp.155-168
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    • 2002
  • The purpose of study to know hand function in order to prevent disability or handicap. The ability to perform precise refined movements of hand is an important human function. Improvement in object manipulation is common goal of therapist. The ability to manipulate an object in the hand is need for many functional tasks, including writing, handling coins, small objects and ADL skills. Therapists have commonly used hand grip and pinch strengths as baseline measures to evaluate hand function. The patterns of grasps are precision grasp, power grasp, hook grasp, spherical grasp, sylindrical grasp, disc grasp, pinch, three point pinch and tip pinch. And the motion of in-manipulation are finger to palm translation, palm to finger, shift, simple rotation and complex rotation. The hand function are include to evaluate of ROM, sensation, muscle strength of hand. It used to evaluate of decision of effect and suppose of disability and acceptance of vocation. Good evaluation is need to pretreatment and baseline of treatment and help to evaluate of effect on treatment.

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Possible Effects of Color Stimuli on Grip and Pinch Strength (색채자극이 악력 및 파지력에 미치는 영향)

  • Kim, Yeon-Ju;Lee, In-Sil;Lim, Soo-Jung
    • Journal of the Korean Society of Physical Medicine
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    • v.3 no.4
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    • pp.293-299
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    • 2008
  • Purpose : The purpose of this study was to investigate the effect of color stimuli on the grip power and the pinch power. Methods : For this experimental study, total 59 healthy college students, who were divided into Red color group and Green color group. Each group was assessed before and after color stimuli(10minutes). Subjects were for using standardized positioning with shoulder adducted and neutrally rotated, elbow flexed at 90 degree and the forearm and wrist in neutral position. Results : All the two groups showed significant differences in the variation of grip power and pinch power under color stimuli(P>.05) but there was no significant variation in grip power and pinch power among groups. Conclusion : This study precedes following study which is focused on the proposal of suitable or appropriate color circumstance for treatment room. Further studies are need with more subjects on long-term outcome.

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Study on LSDC Design for Coiling Shape Control of Hot Strip Mills (열간압연 권취형상 제어를 위한 LSDC 설계에 관한 연구)

  • Lee, Sang Ho;Park, Hong Bae;Park, Cheol Jae
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.9
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    • pp.869-874
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    • 2015
  • We developed an LSDC (Load Shift and Load Distribution Control) technology in order to improve coil quality and productivity by reducing tension fluctuation especially for the tail of the strip in the down coiler in hot strip mills. To adapt the new controller, the torque and speed distribution between the zero pinch roll, pinch roll, and mandrel are needed. The proposed controller is a combination of an LSC to share the tension between the mill stand and the mandrel, and an LDC to shift the torque load from the zero pinch roll to the pinch roll. From the simulation, the proposed controller is verified under the torque disturbance. Using a field test, the torque deviation decreased by nearly 50% through utilization of the LSDC control.

Anti-Pinch System for Power Window by Using Hall Sensor (홀센서를 이용한 파워 윈도우용 안티핀치 시스템)

  • Kim, S.H.;Jeong, S.K.
    • Journal of Power System Engineering
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    • v.14 no.5
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    • pp.63-70
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    • 2010
  • Recently the power window system is widely used in automobiles to increase convenience of passengers and drivers. However some accidents or injuries have been caused by malfunction or misusage of the system. Therefore safety regulations of the system to cope up with these accidents have been strengthened gradually in many countries. Especially in America, since 2005, all vehicles which had power window system should be contented with FMVSS 118-S5 regulations. We suggest very low-cost anti-pinch window control system satisfying the regulation in this paper. Hall sensors are used and installed around a motor rotor with ring magnet to detect motor speed for anti-pinch. The optimum number of hall sensor and location angel of them are mainly investigated to get sufficient speed resolution for anti-pinch. Through some experiments, the validity of the suggested system was verified to satisfy the regulation.

Performance Analysis and Automatic Configuration of Threshold on Anti-Pinch System Based on Current Information for Power Windows (전류정보 기반의 파워 윈도우용 안티핀치 시스템의 전류 임계값 자동 설정 및 성능 분석)

  • Park, Seung-Seob;Jeong, Seok-Kwon
    • Journal of Power System Engineering
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    • v.21 no.5
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    • pp.63-70
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    • 2017
  • This paper deals with anti-pinch system based on current information which prevents some risks for trapping, squeezing or injury to people in smart window on vehicles. Automatic configuration of current threshold is suggested to recognize pinch states in the current based anti-pinch system. Also, some factors affecting to the squeezing force were analyzed by some experimental results and simulations. The validity of the suggested system was verified to satisfy the strengthened American safety regulation, FMVSS 118-S5, through some experimental results.

Study on the High Voltage Pulse Profile Characteristics of a Turbulently Heated Theta Pinch (난류가열 쎄타핀치의 고전압 펄스 발생에 관한 연구)

  • 강형보;정운관;육종철
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.33 no.11
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    • pp.456-463
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    • 1984
  • The fast-rising high-voltage pulse generation circuit system of a theta pinch is both theoretically and experimentally investigated. The idealized model of this circuit system is a hybrid circuit system composed of three parts: a lumped circuit part being consisted of a capacitor bank and a spark switch connected in series, another lumped circuit part being consisted of the Blumlein transmission line, whose end load is the pinch coil. the voltage difference between two ends of the pinch coil is formulated by analyzing this hybrid circuit system by means of the law of the signal propagation in the transmission line and Kirchhoff's laws. The expedient numerical method for computer calculation is developed to generate the pulse profile of the voltage difference across the pinch coil. The period of the experimentally measured main pulse is a fourth of the theoretical one neglecting the resistance of the pinch coil. We attribute this discrepancy to the modelling in the theoretical calculation that hte resistance and inductance of the spark switch and capacitor bank are assumed to be constant through discharge. Therefore, we can see that the rise time of the imploding magnetic-field pulse is mainly dependent on the spark switch and capacitor bank.

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Development of a Real-Time Algorithm for Isometric Pinch Force Prediction from Electromyogram (EMG) (근전도 기반의 실시간 등척성 손가락 힘 예측 알고리즘 개발)

  • Choi, Chang-Mok;Kwon, Sun-Cheol;Park, Won-Il;Shin, Mi-Hye;Kim, Jung
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1588-1593
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    • 2008
  • This paper describes a real-time isometric pinch force prediction algorithm from surface electromyogram (sEMG) using multilayer perceptron (MLP) for human robot interactive applications. The activities of seven muscles which are observable from surface electrodes and also related to the movements of the thumb and index finger joints were recorded during pinch force experiments. For the successful implementation of the real-time prediction algorithm, an off-line analysis was performed using the recorded activities. Four muscles were selected for the force prediction by using the Fisher linear discriminant analysis among seven muscles, and the four muscle activities provided effective information for mapping sEMG to the pinch force. The MLP structure was designed to make training efficient and to avoid both under- and over-fitting problems. The pinch force prediction algorithm was tested on five volunteers and the results were evaluated using two criteria: normalized root mean squared error (NRMSE) and correlation (CORR). The training time for the subjects was only 2 min 29 sec, but the prediction results were successful with NRMSE = 0.112 ${\pm}$ 0.082 and CORR = 0.932 ${\pm}$ 0.058. These results imply that the proposed algorithm is useful to measure the produced pinch force without force sensors in real-time. The possible applications include controlling bionic finger robot systems to overcome finger paralysis or amputation.

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