scholarly journals Temperature profile and residual heat of monopolar laparoscopic and endoscopic dissection instruments

2021 ◽  
Author(s):  
Franz Brinkmann ◽  
Ronny Hüttner ◽  
Philipp J. Mehner ◽  
Konrad Henkel ◽  
Georgi Paschew ◽  
...  
Keyword(s):  
Temperature Profile ◽  
Power Level ◽  
Infrared Camera ◽  
Modern Medicine ◽  
Cooling Time ◽  
Maximum Temperature ◽  
Shaft Length ◽  
Energy Application ◽  
Laparoscopic Tools ◽  
Residual Heat

Abstract Background Endoscopic and laparoscopic electrosurgical devices (ED) are of great importance in modern medicine but can cause adverse events such as tissue injuries and burns from residual heat. While laparoscopic tools are well investigated, detailed insights about the temperature profile of endoscopic knives are lacking. Our aim is to investigate the temperature and the residual heat of laparoscopic and endoscopic monopolar instruments to increase the safety in handling ED. Methods An infrared camera was used to measure the temperature of laparoscopic and endoscopic instruments during energy application and to determine the cooling time to below 50 °C at a porcine stomach. Different power levels and cutting intervals were studied to investigate their impact on the temperature profile. Results During activation, the laparoscopic hook exceeded 120 °C regularly for an up to 10 mm shaft length. With regards to endoknives, only the Dual Tip Knife showed a shaft temperature of above 50 °C. The residual heat of the laparoscopic hook remained above 50 °C for at least 15 s after activation. Endoknives cooled to below 50 °C in 4 s. A higher power level and longer cutting duration significantly increased the shaft temperature and prolonged the cooling time (p < 0.001). Conclusion Residual heat and maximum temperature during energy application depend strongly on the chosen effect and cutting duration. To avoid potential injuries, the user should not touch any tissue with the laparoscopic hook for at least 15 s and with the endoknives for at least 4 s after energy application. As the shaft also heats up to over 120 °C, the user should be careful to avoid tissue contact during activation with the shaft. These results should be strongly considered for safety reasons when handling monopolar ED.

A Multi-Dwell Temperature Profile Design for the Cure of Thick CFRP Composite Laminates

2021 ◽  
Author(s):  
Wenchang Zhang ◽  
Yingjie Xu ◽  
Xinyu Hui ◽  
Weihong Zhang
Keyword(s):  
Temperature Profile ◽  
Composite Laminates ◽  
Optimization Method ◽  
Maximum Temperature ◽  
Nsga Ii ◽  
Multi Objective ◽  
Optimization Result ◽  
Design Variables ◽  
Cure Time ◽  
Thick Laminates

Abstract This paper develops a multi-objective optimization method for the cure of thick composite laminates. The purpose is to minimize the cure time and maximum temperature overshoot in the cure process by designing the cure temperature profile. This method combines the finite element based thermo-chemical coupled cure simulation with the non-dominated sorting genetic algorithm-II (NSGA-II). In order to investigate the influence of the number of dwells on the optimization result, four-dwell and two-dwell temperature profiles are selected for the design variables. The optimization method obtains successfully the Pareto optimal front of the multi-objective problem in thick and ultra-thick laminates. The result shows that the cure time and maximum temperature overshoot are both reduced significantly. The optimization result further illustrates that the four-dwell cure profile is more e ective than the two-dwell, especially for the ultra-thick laminates. Through the optimization of the four-dwell profile, the cure time is reduced by 51.0% (thick case) and 30.3% (ultra-thick case) and the maximum temperature overshoot is reduced by 66.9% (thick case) and 73.1% (ultra-thick case) compared with the recommended cure profile. In addition, Self-organizing map (SOM) is employed to visualize the relationships between the design variables with respect to the optimization result.

scholarly journals Investigation on the effect of electrode tip on formation of metal droplets and temperature profile in a vibrating electrode electroslag remelting process

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 743-751 ◽  
Author(s):  
Fang Wang ◽  
Jakov Baleta ◽  
Qiang Wang ◽  
Baokuan Li
Keyword(s):  
Temperature Profile ◽  
Electroslag Remelting ◽  
Temperature Fields ◽  
Maximum Temperature ◽  
Periodic Pattern ◽  
Coupled Modelling ◽  
Frequency Changes ◽  
Volume Method ◽  
Peak Value ◽  
Metal Droplets

Abstract In the present work, a transient full-coupled modelling approach has been put forward to study the effect of electrode tip on formation of metal droplets and temperature profile in the electromagnetically-controlled electroslag-remelting furnace with vibrating electrode. The electromagnetic field, momentum and energy conservation equations are solved simultaneously based on the finite volume method. The interface of slag and metal is traced using the volume of fluid approach. The results show that in the case of cone tip electrode the average dimension of metal droplets is smaller compared to the flat tip electrode. In addition, the bigger and stretched metal droplets are not observed with the cone tip electrode. The temperature fields with the cone tip electrode are distributed in a prominent periodic pattern compared to the case with flat tip electrode. The maximum temperature zone with the cone tip electrode is located along the z axial in the upper part of slag, not in the lower part. When the frequency changes from 0.17 Hz to 1 Hz, the maximum temperature reduces from 2050 K to 1985 K and the peak value of velocity decreases from 0.20 m/s to 0.125 m/s. When the vibration amplitude varies from 3mm to 6mm, the maximum temperature in the slag cover drops by 3.9% and the peak value of velocity rises by 16.7%.

Microscale Boiling Heat Transfer Near the Meniscus

2005 ◽  
Author(s):  
Brenda E. Haendler ◽  
David C. Walther ◽  
Dorian Liepmann ◽  
Albert P. Pisano
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Temperature Profile ◽  
Infrared Camera ◽  
Intake Manifold ◽  
Working Fluid ◽  
Bulk Temperature ◽  
Heating Source ◽  
Portable Power ◽  
Insight Into

Results are presented experimentally measuring the localized temperature profile due to microscale boiling of a silicon-Pyrex bonded wafer with a 100 μm deep, 500 μm wide and six mm long microchannel. Experiments were performed using an infrared camera equipped with a magnifying lens. By using a camera, the dynamic temperature profile is shown from the inside channel all the way out to where the temperature of the wafer reaches the bulk temperature of the heating source. Temperature profiles are shown for both water and methanol as the working fluid applying between five and twenty degrees Celsius of superheat to the bulk wafer. Using these results, a discussion of the relevant heat transfer modes and nondimensional numbers is given to gain insight into the range of influence that phase change in a microchannel has on the temperature of the wafer. Additionally, discussion is given about modeling of microscale phase change using a commercial fluid dynamics software package. The importance of these results with respect to implementation into the fuel intake manifold for a micro engine based portable power system is also discussed.

Characteristic of Low Calorific Fuel Gas Combustion in a Pressurized Porous Burner

2014 ◽  
Vol 1070-1072 ◽  
pp. 1713-1717
Author(s):  
Guan Qing Wang ◽  
Dan Luo ◽  
Ning Ding ◽  
Jiang Rong Xu
Keyword(s):  
Flame Front ◽  
Temperature Profile ◽  
Axial Direction ◽  
Normal Pressure ◽  
Maximum Temperature ◽  
Combustion Characteristic ◽  
Gas Combustion ◽  
Fuel Gas ◽  
Flame Propagation Velocity ◽  
Porous Burner

Combustion characteristic of low calorific fuel gas in a pressurized porous burner was numerically investigated. The two-dimensional temperature profile, flame front, and CO concentration distribution were analyzed under the pressure at the certain operating parameters, and compared with those of the normal pressure. The results shows that the pressured temperature profile is more clear than that of the normal pressure, and maximum temperature distribution region is larger. Compared with the normal pressure, the pressured flame front location is at the downstream, and the flame propagation velocity along with inclination increases with the pressure increasing. The CO distribution is corresponding to the temperature profile. Its maximum locates at the position of the flame front, and gradually decreasing along the axial direction. It decreases with the pressure increasing, which indicates that the pressure contributes to improve the combustion efficiency.

Experimental Study on Natural Circulation in a Lead Bismuth Eutectic Loop

2017 ◽  
Author(s):  
Leitai Shi ◽  
Guanghui Su ◽  
Tan Bing ◽  
Ronghua Chen ◽  
Wenxi Tian ◽  
...  
Keyword(s):  
Temperature Difference ◽  
Natural Circulation ◽  
Power Level ◽  
Transfer Characteristic ◽  
Normal Operation ◽  
Test Facility ◽  
Maximum Temperature ◽  
Convection Flow ◽  
Operation Temperature ◽  
Heating Section

In order to investigate the thermal-hydraulic characteristics of LBE in Accelerator Driven System (ADS), the Natural Circulation Capability Loop (NCCL) test facility was designed and constructed at Xi’An Jiaotong university in 2015. NCCL is a middle-scale experimental loop designed for investigating the natural circulation capacity, gas-lift pump enhancing circulation capacity and heat-transfer characteristic of LBE. For the natural circulation capability experiment, the loop is filled with argon gas at 0.2 MPa before filling LBE from store tank. The maximum temperature of LBE is 500 C°, while the normal operation temperature was maintained at 400 C°. In this paper, the LBE natural circulation characteristics were investigated with experiments in NCCL test facility. The study includes measurements on start-up of natural circulation and capability of natural circulation. Significant natural convection flow was observed in the experiments. It was found that the natural circulation was quickly established and stabilized due to LBE high thermal expansion property. It took only a few minutes to have a stable natural circulation prevailing from cold conditions. At the same time, the temperature difference between heating section and cooling section increase quickly and reach to the maximum value. And in the range of 10 minutes, a steady circulation can be performed. The natural circulation flowrate depends on the loop resistance, and the temperature difference between the hot leg and the cold leg, as determined by the power level and the heat sink capacity. The experiments show that the maximum flowrate for the natural circulation is 0∼0.81 kg/s.

Through air drying assisted by infrared radiation: the influence of radiator power on drying rates and temperature

2018 ◽  
Vol 33 (4) ◽  
pp. 581-591
Author(s):  
Aron Tysén ◽  
Hannes Vomhoff ◽  
Lars Nilsson
Keyword(s):  
Infrared Radiation ◽  
Power Level ◽  
Infrared Camera ◽  
Drying Time ◽  
Air Drying ◽  
Hot Air ◽  
Ir Heating ◽  
Chemical Pulps ◽  
Drying Rates ◽  
Positive Effect

Abstract The use of infrared radiation for heating the web in the through air drying process was investigated in lab scale. The hypothesis was that infrared radiation should be a more efficient method to transfer drying energy to the wet web compared to hot air, but that a certain air flow is still required as a transport medium for the evaporated water. A trial program comprising handsheets made of two types of bleached chemical pulps, five grammages (15, 22, 30 and 60 g/m²), and dried with five radiator power levels was performed on a lab scale through air drying equipment. Drying times of the samples were determined from temperature data recorded with an infrared camera. The use of infrared radiation shortened drying times, especially for low grammage samples. The shortening of the drying time ranged between 10 and 45 %. The most substantial shortenings were obtained for the lowest grammages and the highest radiator power level. However, the increase of power did not linearly shorten drying time. After an initial shortening at the lowest power level, the positive effect of the IR heating decreased as the power was further increased.

High-Resolution Thermal Profiling of a Combustor in a Non-Dedicated Test Using Thermal History Coatings

2021 ◽  
Author(s):  
David Peral ◽  
Ahmed Zaid ◽  
Christoph Benninghoven ◽  
Silvia Araguas-Rodríguez ◽  
David Kluß ◽  
...  
Keyword(s):  
High Resolution ◽  
Temperature Profile ◽  
Gas Turbine ◽  
Thermal History ◽  
Cooling System ◽  
Maximum Temperature ◽  
Thermal Testing ◽  
Cooling Hole ◽  
Advanced Analysis ◽  
The Impact

Abstract The requirement for reduced emissions and the growing demand on gas turbine efficiency are in part met through increasing firing temperatures. However, development budgets leave only limited time for dedicated thermal testing. Consequently, manufacturers are seeking novel temperature measurement technologies to validate new engine designs. This paper will demonstrate how a new temperature mapping technology can be utilized for non-dedicated (multi-cycling) testing while still delivering high-resolution temperature data in a non-dedicated test on a combustor of an industrial gas turbine. Typically, thermocouples are used to monitor the temperature during tests, but they only provide one data point. Colour changing thermal paints are used to deliver measurements over complete surfaces, but they require dedicated testing with short-duration exposure, necessitating dismantling and re-assembling the engine for further testing. Thermal History Coatings (THC) present an alternative solution to providing high-density temperature information. This coating permanently changes consistent with the maximum temperature of exposure during test. A laser-based instrumentation technique is then used to obtain temperatures. The maximum temperature profile of the surface can be determined through a customized calibration. Given the complex cooling system of a combustor, the high temperatures and the long-time exposure, this case offers a unique possibility for the testing of the coating under real engine conditions. The coated region covered the external surface of the can. Highly significant is the number of measurement points in excess of 7,000 (2 × 2 mm resolution, which enables advanced analysis. This provides insight into the impact of local features, e.g. the region adjacent to a cooling hole. The temperature profile is compared to a CFD-CHT model and thermocouple measurements for the calibration of cooling pre-design methods.

scholarly journals XMM-Newton X-ray and HST weak gravitational lensing study of the extremely X-ray luminous galaxy cluster Cl J120958.9+495352 (z = 0.902)

2018 ◽  
Vol 610 ◽  
pp. A71 ◽  
Author(s):  
Sophia Thölken ◽  
Tim Schrabback ◽  
Thomas H. Reiprich ◽  
Lorenzo Lovisari ◽  
Steven W. Allen ◽  
...  
Keyword(s):  
Temperature Profile ◽  
Gravitational Lensing ◽  
Mass Fraction ◽  
High Redshift ◽  
Galaxy Cluster ◽  
Cooling Time ◽  
Weak Lensing ◽  
Imaging Data ◽  
Weak Gravitational Lensing ◽  
X Ray

Context. Observations of relaxed, massive, and distant clusters can provide important tests of standard cosmological models, for example by using the gas mass fraction. To perform this test, the dynamical state of the cluster and its gas properties have to be investigated. X-ray analyses provide one of the best opportunities to access this information and to determine important properties such as temperature profiles, gas mass, and the total X-ray hydrostatic mass. For the last of these, weak gravitational lensing analyses are complementary independent probes that are essential in order to test whether X-ray masses could be biased. Aims. We study the very luminous, high redshift (z = 0.902) galaxy cluster Cl J120958.9+495352 using XMM-Newton data. We measure global cluster properties and study the temperature profile and the cooling time to investigate the dynamical status with respect to the presence of a cool core. We use Hubble Space Telescope (HST) weak lensing data to estimate its total mass and determine the gas mass fraction. Methods. We perform a spectral analysis using an XMM-Newton observation of 15 ks cleaned exposure time. As the treatment of the background is crucial, we use two different approaches to account for the background emission to verify our results. We account for point spread function effects and deproject our results to estimate the gas mass fraction of the cluster. We measure weak lensing galaxy shapes from mosaic HST imaging and select background galaxies photometrically in combination with imaging data from the William Herschel Telescope. Results. The X-ray luminosity of Cl J120958.9+495352 in the 0.1–2.4 keV band estimated from our XMM-Newton data is LX = (13.4−1.0+1.2) × 1044 erg/s and thus it is one of the most X-ray luminous clusters known at similarly high redshift. We find clear indications for the presence of a cool core from the temperature profile and the central cooling time, which is very rare at such high redshifts. Based on the weak lensing analysis, we estimate a cluster mass of M500 / 1014 M⊙ = 4.4−2.0+2.2(star.) ± 0.6(sys.) and a gas mass fraction of fgas,2500 = 0.11−0.03+0.06 in good agreement with previous findings for high redshift and local clusters.

Thermodynamics Analysis on Combustion Synthesis of β-SiAlON

2014 ◽  
Vol 787 ◽  
pp. 383-386 ◽  
Author(s):  
Xue Mei Yi ◽  
Jing Niu ◽  
Tomohiro Akiyama
Keyword(s):  
Temperature Profile ◽  
Combustion Synthesis ◽  
Nitrogen Pressure ◽  
Main Reaction ◽  
Maximum Temperature ◽  
Nitrogen Gas ◽  
Exothermic Reactions ◽  
Thermodynamics Analysis ◽  
Intermediate Products ◽  
Endothermic Reactions

Combustion synthesis (CS) of β-SiAlON (z= 1) was carried by heating the raw mixtures of Si, Al, and SiO2under a constant nitrogen pressure of 1 MPa to the preconcerted temperature. The temperature profile was recorded by a W-Re thermocouple, which showed several exothermic and endothermic reactions during the entire CS process. The maximum temperature reached above 1900°C, and two main exothermic reactions at ~800 °C and ~1350 °C were found. The XRD analyses indicated that the main intermediate products are AlN, SiO2, and Al2O3before β-SiAlON was synthesized finally. From our analyses, Al reacted with nitrogen gas at ~800 °C first, then at ~1350 °C, the main reaction occurred and the final product was obtained synchronously.

scholarly journals An Analytic Analysis of the Diffusive-Heat-Flow Equation for Different Magnetic Field Profiles for a Single Magnetic Nanoparticle

2012 ◽  
Vol 2012 ◽  
pp. 1-22 ◽  
Author(s):  
Brenda Dana ◽  
Israel Gannot
Keyword(s):  
Magnetic Field ◽  
Heat Flow ◽  
Temperature Profile ◽  
Magnetic Nanoparticle ◽  
Temperature Response ◽  
Flow Equation ◽  
Maximum Temperature ◽  
Transient Temperature ◽  
Muscular Tissue ◽  
Temperature Increment

This study analytically analyzes the changes in the temperature profile of a homogenous and isotropic medium having the same thermal parameters as a muscular tissue, due to the heat released by a single magnetic nanoparticle (MNP) to its surroundings when subject to different magnetic field profiles. Exploring the temperature behavior of a heated MNP can be very useful predicting the temperature increment of it immediate surroundings. Therefore, selecting the most effective magnetic field profile (MFP) in order to reach the necessary temperature for cancer therapy is crucial in hyperthermia treatments. In order to find the temperature profile caused by the heated MNP immobilized inside a homogenous medium, the 3D diffusive-heat-flow equation (DHFE) was solved for three different types of boundary conditions (BCs). The change in the BC is caused by the different MF profiles (MFP), which are analyzed in this article. The analytic expressions are suitable for describing the transient temperature response of the medium for each case. The analysis showed that the maximum temperature increment surrounding the MNP can be achieved by radiating periodic magnetic pulses (PMPs) on it, making this MFP more effective than the conventional cosine profile.

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