scholarly journals UPGRADE OF THE LANGENDORFF APPARATUS USING THE INFRARED THERMO-CONTROL SYSTEM AND AN INTELLIGENT HEATER

2020 ◽  
Vol 50 (4) ◽  
pp. 137-141
Author(s):  
Josef Skopalík ◽  
Jiří Sekora ◽  
Martin Pešl ◽  
Markéta Bébarová ◽  
Olga Švecová ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Control System ◽  
Real Time ◽  
Ex Vivo ◽  
Infrared Camera ◽  
Tissue Temperature ◽  
Temperature Control System ◽  
Perfusion Solution ◽  
Basic Set ◽  
Heating Bath

Biological experiments involving isolated organs and tissues demand precise temperature monitoring and regulation. An automatic temperature control system was proposed and optimised on real isolated swine hearts and the prototype is described in this work. The traditional Langendorff apparatus consists of a heart holder, a reservoir of perfusion solution flowing to aortic cannula and a heating bath allowing passive heat transfer to the reservoir of perfusion solution. The commercial infrared camera FLIR T62101 was added to this basic set-up and used for very precise monitoring of the temperature kinetic of the organ and connected with an electronic feedback loop, which allowed real-time and precise regulation of heat transfer from the heating bath to the perfusion solution and in turn indirectly to the heart tissue. This provides real time control and active regulation of the myocardial tissue temperature. The infrared camera was tested in several modes and several variants of detection were optimised for ideal measurement of the region of interest of the ex vivo organ. The kinetics of the temperature changes and temperature stability of the tissue were recorded and calibrated by external electronic thermometers (type Pt100, inserted in tissue). The time lapse from the hang-up of the hypo termed organ (30 °C) until optimal warming (37 °C) was less than eight minutes in the final instrument prototype. The final stability of the 37 °C tissue temperature was approved; the temperature fluctuation of left ventricle tissue was characterised as 36.8 ± 0.5 °C. This upgraded traditional instrument could be used in specific preclinical and clinical transplantation and analytical projects in future.

scholarly journals Design of Temperature Fluctuation Test Platform Based on Radiation Heat Transfer

2019 ◽  
Vol 256 ◽  
pp. 03002
Author(s):  
Han Xiao ◽  
Zhou Ying ◽  
Jia Ruijin ◽  
Zijuan Wang
Keyword(s):  
Heat Transfer ◽  
Control System ◽  
Temperature Fluctuation ◽  
Radiation Heat Transfer ◽  
Temperature Control System ◽  
Time Varying ◽  
Radiation Heat ◽  
Fluctuation Test ◽  
Theoretical Support ◽  
Test Platform

The optical characteristics of the space science detectors are very sensitive to the temperature fluctuation. In order to study the effect of it, a method to simulate the temperature fluctuation was put forward in this paper, and the feasibility of this method was verified numerically. A radiation disturbance was artificially applied at a certain distance from the test platform, so that the surface temperature of the platform changed periodically with the radiation heater. The results show that the radiation heat transfer disturbance could produce a temperature fluctuation on the test platform, which provides a reliable theoretical support for the time-varying temperature control system.

Temperature Check and Control System Based on Micro Controller

2012 ◽  
Vol 529 ◽  
pp. 450-453
Author(s):  
Na Li ◽  
Huan Yin Guo ◽  
Hai Fang Mu
Keyword(s):  
Control System ◽  
Real Time ◽  
Temperature Control ◽  
Production Efficiency ◽  
Temperature Control System ◽  
The Core ◽  
Heating Wire ◽  
Temperature Signal ◽  
And Control ◽  
Micro Controller Unit

This thesis has designed a temperature control system which takes Micro controller Unit AT89S51 as the core. Temperature signal received from sensor DS18B20 is analysed by AT89S51. It adjusts temperature using relay heating wire and fan. 1602LCD display the current temperature value and buzzer could give an alarm. The system can detect and regulate temperature in real time. It contributes to production efficiency.

MCU based real-time temperature control system for universal microfluidic PCR chip

2013 ◽  
Vol 20 (3) ◽  
pp. 471-476 ◽  
Author(s):  
Dawoon Han ◽  
You-Cheol Jang ◽  
Sung-Nam Oh ◽  
Rohit Chand ◽  
Ki-Tae Lim ◽  
...  
Keyword(s):  
Control System ◽  
Real Time ◽  
Temperature Control ◽  
Temperature Control System

Radiofrequency Thermal Ablation Heat Energy Transfer in an Ex-Vivo Model

2017 ◽  
Vol 83 (12) ◽  
pp. 1373-1380 ◽  
Author(s):  
Shivani Thakur ◽  
Sandi Lavito ◽  
Elizabeth Grobner ◽  
Mark Grobner
Keyword(s):  
Heat Transfer ◽  
Energy Transfer ◽  
Ex Vivo ◽  
Heat Energy ◽  
Tissue Temperature ◽  
Ex Vivo Model ◽  
Temperature Changes ◽  
Ablation Therapy ◽  
Heat Degradation ◽  
Human Calf

Little work has been done to consider the temperature changes and energy transfer that occur in the tissue outside the vein with ultrasound-guided vein ablation therapy. In this experiment, a ex-vivo model of the human calf was used to analyze heat transfer and energy degradation in tissue surrounding the vein during endovascular radiofrequency ablation (RFA). A clinical vein ablation protocol was used to determine the tissue temperature distribution in 10 per cent agar gel. Heat energy from the radiofrequency catheter was measured for 140 seconds at fixed points by four thermometer probes placed equidistant radially at 0.0025, 0.005, and 0.01 m away from the RFA catheter. The temperature rose 1.5°C at 0.0025 m, 0.6°C at 0.005 m, and 0.0°C at 0.01 m from the RFA catheter. There was a clinically insignificant heat transfer at the distances evaluated, 1.4 ± 0.2 J/s at 0.0025 m, 0.7 ± 0.3 J/s at 0.0050 m, and 0.3 ± 0.0 J/s at 0.01 m. Heat degradation occurred rapidly: 4.5 ± 0.5 J (at 0.0025 m), 4.0 ± 1.6 J (at 0.0050 m), and 3.9 ± 3.6 J (at 0.01 m). Tumescent anesthesia injected one centimeter around the vein would act as a heat sink to absorb the energy transferred outside the vein to minimize tissue and nerve damage and will help phlebologists strategize options for minimizing damage.

Study on heat transfer characteristics and thermal error suppression method of cylindrical giant magnetostrictive actuator for ball screw preload

2020 ◽  
pp. 095440542097296
Author(s):  
Xiaojun Ju ◽  
Jili Lu ◽  
Hongyan Jin
Keyword(s):  
Heat Transfer ◽  
Control System ◽  
Temperature Control ◽  
Thermal Error ◽  
Circuit Model ◽  
Ball Screw ◽  
Temperature Control System ◽  
Thermal Circuit ◽  
Suppression Method ◽  
Error Suppression

Based on the structure analysis and the working principle of cylindrical giant magnetostricve actuator (CGMA) for ball screw preload, a thermal error suppression method using oil cooling system to control the temperature is proposed. Firstly, the heat transfer model and thermal circuit model of CGMA are established; next, the steady-state temperature model and the thermal expansion displacement model of cylindrical giant magnetostrictive material (CGMM) are obtained according to the heat-transfer rules and loop analysis method in circuit analysis; finally, the design parameters of the oil-cooling temperature control system are determined by combining thermal circuit model analysis with finite element simulation analysis. Such optimization method saves a lot of computation and provides a simple way for the design of oil cooling structure. In addition, a test platform for the CGMA is established. The experimental results indicate that the measured temperatures are in good agreement with the simulation results under forced oil cooling, and the relative error is less than 5%, which proves the rationality of the temperature control system. Moreover, the output accuracy and stability of the CGMA is significantly improved with proposed oil cooling method, which further confirms the thermal error suppression method is effective. As a result, this study provides a basis for the application of CGMA in the precise adjustment of double-nut ball screw preload.

scholarly journals An Investigation of a Nonlinear Fuel Oil Viscosity and Temperature Control System for Ships

2019 ◽  
Vol 95 ◽  
pp. 03006
Author(s):  
Zhuohang Ye ◽  
Xiaobing Mao ◽  
Hai Huang ◽  
Xianzhen Liu
Keyword(s):  
Heat Transfer ◽  
Control System ◽  
Sliding Mode ◽  
Variable Structure ◽  
Fuel Oil ◽  
Temperature Control System ◽  
Transfer Model ◽  
Oil Viscosity ◽  
Single Input ◽  
Sliding Mode Variable Structure

In this paper, the differential equation of the fuel oil viscosity and temperature control system was derived, according to the working processes and principles of the heating of heavy oil in ocean vessels. By analyzing the characteristics of the heat transfer model, a multi-input coupling nonlinear heat transfer model was developed, in which the temperatures at the inlet and the outlet of the heavy oil heater were used as the state variables, while the openings of the regulating valve of the mixed oil tank and the steam flow rate regulating valve of the heater were used as the control inputs. This model can be decomposed into a single-input nonlinear system and single-input second-order linear system for further investigation, and the sliding mode variable structure controller can then be solved by performing linear reductions on the nonlinear model. Finally, using KING VIKW software, experiments were performed in order to examine the controlling performances of the PID and sliding mode variable structure ( SMVS ) controller respectively. The results show that the sliding mode variable structure controller exhibits a series of superiorities, which mainly include a small overshoot, fast response and strong anti-interference capability.

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