scholarly journals A Fast and Accurate Method for Computing the Microwave Heating of Moving Objects

2020 ◽  
Vol 10 (8) ◽  
pp. 2985
Author(s):  
Min Zhang ◽  
Xiubo Jia ◽  
Zhixiang Tang ◽  
Yixuan Zeng ◽  
Xuejiao Wang ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Moving Objects ◽  
Computing Time ◽  
Accurate Method ◽  
High Energy ◽  
Good Choice ◽  
Heating Process ◽  
Arbitrary Lagrangian Eulerian ◽  
Dielectric Parameters ◽  
Arbitrary Lagrangian Eulerian Method

In this paper, we show a fast and accurate numerical method for simulating the microwave heating of moving objects, which is still a challenge because of its complicated mathematical model simultaneously coupling electromagnetic field, thermal field, and temperature-dependent moving objects. By contrast with most discrete methods whose dielectric parameters of the heated samples are updated only when they move to a new position or even turn a circle, in our simulations a real-time procedure is added to renew the parameters during the whole heating process. Furthermore, to avoid the mesh-mismatch induced by remeshing the moving objects, we move the cavity instead of samples. To verify the efficiency and accuracy, we compared our method with the arbitrary Lagrangian–Eulerian method, one of the most accurate methods for computing this process until now. For the same computation model, our method helps in decreasing the computing time by about 90% with almost the same accuracy. Moreover, the influence of the rotational speed on the microwave heating is systematically investigated by using this method. The results show the widely used speed in domestic microwave ovens, 5 rpm, is indeed a good choice for improving the temperature uniformity with high energy efficiency.

A method for coupled microwave heating process and heat transfer simultaneously of moving objects

2017 ◽  
Vol 42 (2) ◽  
pp. e13468
Author(s):  
Pu Guang Yi ◽  
Pu Cheng Xi ◽  
Jun Wang ◽  
Song Chun Fang
Keyword(s):  
Heat Transfer ◽  
Microwave Heating ◽  
Moving Objects ◽  
Heating Process

Researches Regarding Elaboration of Barium Hexaferrite from Microwave Heating

2012 ◽  
Vol 188 ◽  
pp. 369-375 ◽  
Author(s):  
Iulian Ştefan ◽  
Sorin Savu ◽  
Olimpia Ghermec ◽  
Claudiu Nicolicescu ◽  
Mario Trotea
Keyword(s):  
Microwave Heating ◽  
Raw Materials ◽  
Barium Hexaferrite ◽  
High Energy ◽  
Homogeneous Mixture ◽  
Heating Process ◽  
Powder Size ◽  
Mechanically Alloyed ◽  
High Energy Ball Mill ◽  
Energy Ball

The paper presents the results of experimental researches on the formation of barium hexaferrite type M (BHFM) by microwave heating. The microwave heating process takes only a few minutes to obtain calcined barium ferrite powders. Micronic and nanometric powders of BaCO3 and α-Fe2O3 were used as raw materials. In order to obtain BHFM, the microwave heating process was used with following mixtures: stoichiometric homogeneous mixture of BaCO3 and α-Fe2O3 powders, mechanically alloyed mixtures of BaCO3 and α-Fe2O3 powders for 5 and 20 hours in wet medium using a high energy ball mill Pulverisette 4. Using high energy ball milling, the powder size was turned into nanoscale. After using the microwave heating process it was observed a significant reduction of temperature-time parameters to BHFM formation for mechanically alloyed mixtures compared to homogeneous mixture.

Usefulness of Foundry Tooling Materials in Microwave Heating Process

2013 ◽  
Vol 58 (3) ◽  
pp. 919-922 ◽  
Author(s):  
K. Granat ◽  
B. Opyd ◽  
D. Nowak ◽  
M. Stachowicz ◽  
G. Jaworski
Keyword(s):  
Electromagnetic Field ◽  
Microwave Heating ◽  
Loss Factor ◽  
Perturbation Technique ◽  
Resonant Cavity ◽  
Precise Determination ◽  
Heating Process ◽  
Basic Criterion ◽  
Measurement Results ◽  
Heating Technology

Abstract The paper describes preliminary examinations on establishing usefulness criteria of foundry tooling materials in the microwave heating technology. Presented are measurement results of permittivity and loss tangent that determine behaviour of the materials in electromagnetic field. The measurements were carried-out in a waveguide resonant cavity that permits precise determination the above-mentioned parameters by perturbation technique. Examined were five different materials designed for use in foundry tooling. Determined was the loss factor that permits evaluating usefulness of materials in microwave heating technology. It was demonstrated that the selected plastics meet the basic criterion that is transparency for electromagnetic radiation.

Nitrogen and Sulfur Co-doped Fluorescent Carbon Dots for the Detection of Morin and Cell Imaging

2018 ◽  
Vol 15 (1) ◽  
pp. 47-55
Author(s):  
Xuebing Li ◽  
Haifen Yang ◽  
Ning Wang ◽  
Tijian Sun ◽  
Wei Bian ◽  
...  
Keyword(s):  
Microwave Heating ◽  
Fluorescent Probe ◽  
Fluorescence Intensity ◽  
Carbon Dots ◽  
Cell Imaging ◽  
Water Soluble ◽  
Heating Process ◽  
X Ray ◽  
Doped Carbon Dots ◽  
Co Doped

Background: Morin has many pharmacological functions including antioxidant, anticancer, anti-inflammatory, and antibacterial effects. It is commonly used in the treatment of antiviral infection, gastropathy, coronary heart disease and hepatitis B in clinic. However, researches have shown that morin is likely to show prooxidative effects on the cells when the amount of treatment is at high dose, leading to the decrease of intracellular ATP levels and the increase of necrosis process. Therefore, it is necessary to determine the concentration of morin in biologic samples. Method: Novel water-soluble and green nitrogen and sulfur co-doped carbon dots (NSCDs) were prepared by a microwave heating process with citric acid and L-cysteine. The fluorescence spectra were collected at an excitation wavelength of 350 nm when solutions of NSCDs were mixed with various concentrations of morin. Results: The as-prepared NSCDs were characterized by transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The fluorescence intensity of NSCDs decreased significantly with the increase of morin concentration. The fluorescence intensity of NSCDs displayed a linear response to morin in the concentration 0.10-30 μM with a low detection limit of 56 nM. The proposed fluorescent probe was applied to analysis of morin in human body fluids with recoveries of 98.0-102%. Conclusion: NSCDs were prepared by a microwave heating process. The present analytical method is sensitive to morin. The quenching process between NSCDs and morin is attributed to the static quenching. In addition, the cellular toxicity on HeLa cells indicated that the as-prepared NSCDs fluorescent probe does not show obvious cytotoxicity in cell imaging. Our proposed method possibly opens up a rapid and nontoxic way for preparing heteroatom doped carbon dots with a broad application prospect.

Investigation of rain erosion on a brittle material by means of numerical simulation

2011 ◽  
Vol 9 (4) ◽  
pp. 327-334
Author(s):  
H Anıl Salman ◽  
R Orhan Yıldırım
Keyword(s):  
Brittle Material ◽  
Plate Thickness ◽  
Material Model ◽  
Float Glass ◽  
Water Jet ◽  
Arbitrary Lagrangian Eulerian ◽  
Arbitrary Lagrangian Eulerian Method ◽  
Maximum Water ◽  
Water Speed ◽  
Rain Erosion

In this work, the resistance and deformation characteristics of a brittle material against rain erosion are examined by using the non-linear, explicit software LS-DYNA. The water jet with varying speeds impinges at 90° on silica float glass plates with different thicknesses. In the simulations, the Arbitrary Lagrangian Eulerian method is used for modelling of the water. In order to analyse the deformations on the brittle material Johnson–Holmquist–Ceramics (JH-2) is used as the material model. Minimum plate thickness (for constant water jet speed) and maximum water speed (for constant plate thickness), which do not cause any damage to the target, are determined depending on the geometry, boundary conditions and assumed failure strain value for erosion. The results are compared with the water-hammer pressure.

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