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Experimental Studies of The Evaporation of Pure Liquid Droplets in A Single-Axis Non-Resonant Levitator

2026-05-06T14:31:04Z

Title: Experimental Studies of The Evaporation of Pure Liquid Droplets in A Single-Axis Non-Resonant Levitator Authors: Radmilović-Radjenović, M.; Rađenović, Dimitrije; Mitrić, M.; Radjenović, B. Abstract: Though a simple daily observation, evaporation of drops is still poorly understood due to the complex nature that involves hydrodynamic effects in the bulk fluids and transport phenomena at the liquid-vapor interface. This paper reports on the evaporation of single component droplets (water, ethanol, acetone, and glycerol) levitated in a single-axis non-resonant levitator. It was observed that the acetone and ethanol evaporated faster than water, although the acetone is the most volatile. The estimated lifetime of acetone is less than 5min, which is much shorter as compared to 56min for ethanol or about 90min for water droplets. On the other hand, glycerol showed no tendency to evaporate. With increasing the evaporation time, the ratio of large and small semi-axis decreases and tends to 1 corresponding to changes in drops shape from oblate ellipsoid to a sphere. Based on the classical D²-law, the surface regression rates have been estimated.

Finite element analysis of the effect of microwave ablation on the liver, lung, kidney, and bone malignant tissues

2026-05-06T13:52:14Z

Title: Finite element analysis of the effect of microwave ablation on the liver, lung, kidney, and bone malignant tissues Authors: Radmilović-Radjenović, M.; Rađenović, Dimitrije; Radjenović, B. Abstract: Microwave ablation becomes a promising thermal modality for treating cancerous tumor cells in patients who are non-surgical candidates. To ensure the destruction of cancer cells with minimal damage to healthy tissue, the elevation of temperature and the evolution of the necrotic tissue need to be controlled. Besides experimental methods, computer modeling evolves into a powerful approach for improving the performance of the ablative treatment. This letter reports on the numerical studies of the microwave ablation effect on the liver, lung, kidney, and bone tumoral tissues. Calculations were performed by using the COMSOL Multiphysic based on a multi-component plasma fluid model. Simulation conditions include the microwave frequency of, the input power of, and taking into account the temperature dependence of dielectric properties of the tissue. The total loss power density, the temperature distribution, the fraction of the tissue damage, and the specific absorption rate have been determined. It was shown that the temperature distribution has an ellipsoidal shape reaching the maximal values required for effective cancer treatment but to avoid damaging healthy cells near the antenna slot. From the degree of tissue injury, the fraction of damage has been estimated revealing that the microwave ablation zones are concentrated around the tip and slot of the antenna. Also, the ablation of the tumor cells can be achieved over a long period without damaging healthy cells when small input power is used. The obtained results confirm that simulations can be very useful for predicting optimal conditions for the minimal damage of the healthy tissue during microwave ablation, and therefore may be implemented into treatment planning. ©

The effect of grinding on the apparent color of the yellow sugar powder

2026-05-06T13:25:39Z

Title: The effect of grinding on the apparent color of the yellow sugar powder Authors: Radmilović-Rađenović, Marija; Rađenović, Dimitrije; Rađenović, Branislav Abstract: Understanding the grinding technique as a very useful tool for super fine powder manufacturing is critically important. The colors of powders are related to the fineness of the powder. This paper contains the results of experimental studies of the effect of grinding on the color of the yellow sugar powder. The fineness of the yellow sugar samples has been monitored by a granulometric analysis. The powder sample is sifting through a stack of mesh sieves, separating it into discrete size ranges. After sieving, yellow sugar powder distinguished by various degrees of grinding is transferred directly to the computer screen by a USB microscope. Color changes have been studied by using RGB (Red, Green, Blue) and HSL (Hue, Saturation, Lightness) color models. For the yellow sugar, color changes from dark yellow to white due to diffuse reflection on the powder particles. By fitting the experimental data the dependence of the L and S values on diameter has been established. Based on recorded Raman spectra, the diffusive reflectance and the absorption coefficients have been determined.

Mатематика 7 : уџбеник за седми разред основне школе [8. izd.]

2026-05-06T12:32:28Z

Title: Mатематика 7 : уџбеник за седми разред основне школе [8. izd.] Authors: Ikodinović, Nebojša; Dimitrijević, Slađana