Assistance of metal nanoparticles in photocatalysis – nothing more than a classical heat source

2019 ◽  
Vol 214 ◽  
pp. 215-233 ◽  
Author(s):  
Yonatan Sivan ◽  
Ieng Wai Un ◽  
Yonatan Dubi
Keyword(s):  
Heat Source ◽  
Metal Nanoparticles ◽  
Thermal Effect ◽  
Chemical Reactions ◽  
Thermal Equilibrium ◽  
High Energy

We show that the number of high energy non-thermal electrons in a metal under CW illumination is very low but much higher than in thermal equilibrium, implying that faster chemical reactions reported previously are extremely likely to originate from a pure thermal effect.

scholarly journals Calculation Of Pressure Rise And Energy Of Hot Gases Due To High Energy Arcing Faults In The Metal-clad Switchgear

2017 ◽  
Vol 4 (2) ◽  
pp. 116-119
Author(s):  
M. Iwata ◽  
T. Miyagi ◽  
Y. Goda ◽  
K. Shirai
Keyword(s):  
Thermal Effect ◽  
Pressure Rise ◽  
High Energy ◽  
Arcing Faults ◽  
Pressure Development ◽  
Calculation Results ◽  
Roof Panel

This paper presents the 3-D CFD calculation results of the pressure rise due to the High Energy Arcing Faults (HEAFs) in the metal-clad switchgears. The calculations were performed considering the came-off of the roof panel that was observed in the arc tests. The calculated pressure development approximately agreed with the measured one. Furthermore, the energy of hot gases exhausted from the broken roof panel was calculated to investigate the thermal effect of hot gases.

Thermal Effect of High Energy Repetition Rate Nd∶Glass Laser

2020 ◽  
Vol 47 (9) ◽  
pp. 0901004
Author(s):  
杨思达 Yang Sida ◽  
印定军 Yin Dingjun ◽  
甘泽彪 Gan Zebiao ◽  
陈俊驰 Chen Junchi ◽  
姚波 Yao Bo ◽  
...  
Keyword(s):  
Thermal Effect ◽  
Repetition Rate ◽  
High Energy ◽  
Glass Laser

Chemical reactions during high-energy ball milling of the Cu2(OH)2CO3–Al0 system

2003 ◽  
Vol 164 (3-4) ◽  
pp. 193-198 ◽  
Author(s):  
Krystyna Wieczorek-Ciurowa ◽  
Katarzyna Gamrat ◽  
Katarzyna Fela
Keyword(s):  
Ball Milling ◽  
Chemical Reactions ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Energy Ball

Simulation of Mixing Induced by a Hot PAR Exhaust Plume

2012 ◽  
Author(s):  
Michele Andreani ◽  
Stephan Kelm
Keyword(s):  
Heat Source ◽  
Thermal Effect ◽  
Large Scale ◽  
Coarse Mesh ◽  
Mixing Process ◽  
Computational Tools ◽  
Simultaneous Injection ◽  
Exhaust Plume ◽  
Substantial Discrepancy ◽  
Ansys Cfx

Passive Autocatalytic Recombiners (PARs) are installed in various reactor containment designs to mitigate the hydrogen risk. For the evaluation of the effectiveness of these devices, validated computational tools are needed. To build confidence in the codes, their capability must also be assessed against separate effect tests addressing specific phenomena. Within the OECD SETH 2 project three experiments have been performed in the large-scale PANDA facility, where the thermal effect of a PAR was simulated by means of a heater and the plume generated by the heat source interacted with an initially stratified ambient. In these tests, helium was used instead of hydrogen. The position of the heater and the presence of simultaneous injection of steam were varied in these tests. These experiments have been analyzed with the GOTHIC and the ANSYS CFX codes. This paper reports only the results obtained with the GOTHIC code. In general, the GOTHIC code in conjunction with a coarse mesh could predict the mixing process reasonably well. The only substantial discrepancy with the experiments was the overprediction of the velocity at the inlet of the heater case, but this had little effect on the simulation of the overall mixing.

scholarly journals Non-Equilibrium Liouville and Wigner Equations: Classical Statistical Mechanics and Chemical Reactions for Long Times

Entropy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 179 ◽  
Author(s):  
Ramon Álvarez-Estrada
Keyword(s):  
Orthogonal Polynomials ◽  
Chemical Reactions ◽  
Thermal Equilibrium ◽  
Three Dimensional ◽  
Liapunov Function ◽  
Heat Bath ◽  
Wigner Functions ◽  
Statistical Systems ◽  
Non Equilibrium

We review and improve previous work on non-equilibrium classical and quantum statistical systems, subject to potentials, without ab initio dissipation. We treat classical closed three-dimensional many-particle interacting systems without any “heat bath” ( h b ), evolving through the Liouville equation for the non-equilibrium classical distribution W c , with initial states describing thermal equilibrium at large distances but non-equilibrium at finite distances. We use Boltzmann’s Gaussian classical equilibrium distribution W c , e q , as weight function to generate orthogonal polynomials ( H n ’s) in momenta. The moments of W c , implied by the H n ’s, fulfill a non-equilibrium hierarchy. Under long-term approximations, the lowest moment dominates the evolution towards thermal equilibrium. A non-increasing Liapunov function characterizes the long-term evolution towards equilibrium. Non-equilibrium chemical reactions involving two and three particles in a h b are studied classically and quantum-mechanically (by using Wigner functions W). Difficulties related to the non-positivity of W are bypassed. Equilibrium Wigner functions W e q generate orthogonal polynomials, which yield non-equilibrium moments of W and hierarchies. In regimes typical of chemical reactions (short thermal wavelength and long times), non-equilibrium hierarchies yield approximate Smoluchowski-like equations displaying dissipation and quantum effects. The study of three-particle chemical reactions is new.

Numerical Evaluation of Multiple Phase Change Materials for Pulsed Electronics Applications

2016 ◽  
Author(s):  
David Gonzalez-Nino ◽  
Lauren M. Boteler ◽  
Dimeji Ibitayo ◽  
Nicholas R. Jankowski ◽  
Pedro O. Quintero
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Source ◽  
Phase Change ◽  
Phase Change Materials ◽  
High Energy ◽  
Heat Of Fusion ◽  
Maximum Temperature ◽  
Conductivity Enhancement ◽  
Fast Transient

A simple and easy to implement 1-D heat transfer modeling approach is presented in order to investigate the performance of various phase change materials (PCMs) under fast transient thermal loads. Three metallic (gallium, indium, and Bi/Pb/Sn/In alloy) and two organic (erythritol and n-octadecane) PCMs were used for comparison. A finite-difference method was used to model the transient heat transfer through the system while a heat integration or post-iterative method was used to model the phase change. To improve accuracy, the material properties were adjusted at each iteration depending on the state of matter of the PCM. The model assumed that the PCM was in direct contact with the heat source, located on the top of the chip, without the presence of a thermal conductivity enhancement. Results show that the three metallic PCMs outperform organic PCMs during fast transient pulses in spite of the fact that two of the metallic PCMs (i.e. indium and Bi/Pb/Sn/In) have considerably lower volumetric heats of fusion than erythritol. This is due to the significantly higher thermal conductivity values of metals which allow faster absorption of the heat energy by the PCM, a critical need in high-energy short pulses. The most outstanding case studied in this paper, Bi/Pb/Sn/In having only 52% of erythritol’s heat of fusion, showed a maximum temperature 20°C lower than erythritol during a 32 J and 0.02 second pulse. This study has shown thermal buffering benefits by using a metallic PCM directly in contact with the heat source during short transient heat loads.

scholarly journals Design of Infrared Radiation for Best Heat Source Performance in Paint Cure Oven

2019 ◽  
Vol 8 (3) ◽  
pp. 7882-7885
Keyword(s):  
Heat Source ◽  
Forced Convection ◽  
Metal Surface ◽  
Infrared Radiation ◽  
Powder Coating ◽  
High Energy ◽  
Infrared Heating ◽  
Coating Process ◽  
Radiation Heating ◽  
Complex Shapes

This project aims at altering the conveyor speed for maximum productivity and modifying the oven in order to increase the efficiency of powder coating process involved in painting the components of lifts. The primary thing to be considered while modifying the oven is the heat source provided. Most of the industries use forced convection for heating up the product in order to cure the powder coating process. This project aims at providing infrared radiation as the heat source to cure the powder over the metal surface. Forced convection is advantageous for more complex shapes. But the components of lifts are not of complex shapes. So, it would be efficient to use infrared. The forced convection system requires long heat up time, high energy consumption, large floor area and some additional setups for air circulation inside the oven. Infrared radiation heating would eliminate these drawbacks. The infrared radiation would be absorbed by the material in order to heat up. This is more efficient in case of curing the powder coated parts. Because, in case of forced convection first the paint in form of powder is heated and then the heat is transferred to the metal surface. Whereas in case of infrared heating, the metal would be heated first and then it would be transferred towards the powder paint. In other words, we could say that the infrared radiation heating provides backward heating which would increase the efficiency and life of the paint coated. Temperature control and instant heating are also the advantages of infrared heating. Hence designing the infrared source for the given metal and powder specifications is done in this project.

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