[en] The present article discusses the effect of nanoparticles on the performance of cryosurgery. In cryosurgery, the cancerous cells have been destroyed by freezing them with the help of cryoprobes. The major challenge during cryosurgery is to minimize/eliminate the cryoinjury to the surrounding healthy tissue. So, it is essential to understand the thermal behavior of biological tissue during cryosurgery. Researchers suggested that injecting nanoparticles into biological tissue can protect healthy tissue from cryoinjury. So, different types of nanoparticles such as Au, Fe₃O₄, and Al₂O₃ have been considered in the present study. This problem has been simulated using the ANSYS Fluent 18.1 version of the CFD software package. The three-dimensional cubical shape of biological tissue with a single cryoprobe has been considered in the present study. First, the current numerical results have been verified with the results available in the literature under the same operating conditions. Then, the grid-independent study was performed to select the optimum grid size. After that, the effect of earlier mentioned nanoparticles on the iceball formation and temperature distribution inside the biological tissue have been investigated to select suitable nanoparticles. The effect of the volumetric concentration of nanoparticles is also studied. A comparative study between the biological tissue with and without nanoparticles has been conducted. The present study may help to improve cryosurgery's efficacy. (author)

[en] The present work proposes a practical level of γ-Ray to lower the molecular weigh of chitosan irradiated in solid state and water. The molecular weight reduction is up to 80% at γ-ray amount of 50 kGy. The same level of reduction can be achieved by only 20 kGy in the presence of initiator (K₂S₂O₈ or H₂O₂). The structure is significantly changed in the case of chitosan-acetic acid solution or chitosan dispersed in water with 2% aq. K₂S₂O₈ solution

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[en] In this article investigated the homo- and heterovalent coordinating combinations of Fe(III)-Fe(II) dibazole

[en] Freezing temperature lowerings of aqueous solutions of tartaric acid, sodium hydrogen tartrate, sodium dihydrogen citrate, potassium dihydrogen citrate, disodium hydrogen citrate, sodium citrate and potassium citrate were determined. These values and those taken from the literature for potassium tartrate were used in the determination of the osmotic and activity coefficients in the studied systems, via the numerical integration of the Gibbs-Duhem equation

[en] This work is a study of the reactions within liquid bromine trifluoride, between an alkaline fluoride and uranium tetrafluoride. It uses conductimetric and cryoscopic measurements. Our work is in five parts: 1. General information: methods of analysis and preparation of BrF₃; 2. Conductimetric measurements in BrF₃; 3. Cryoscopic study in BrF₃; 4. Solid-state study of the precipitates obtained by the mutual reaction of M[BrF₄] and UF₄; 5. Summary and conclusions. (author)

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[en] The solubility problems raised by certain components of the polymeric residue of irradiated polyphenylic coolants, which make it necessary to operate with very small samples, have been solved by means of a differential cryoscopic technique, with which have been associated an automatic device and a thermoelectric thermometer (a group of thermocouples joined in series) as sensitive element. The method is based on the direct measurement of the difference between the freezing points of the solution being investigated and of a reference solution whose concentration may be varied at will. The variation of ΔV (mV) versus c(moles/1000 g solvent) is linear, the point of equivalence being determined either analytically or graphically depending on the accuracy required. The method has been checked experimentally on pure polyphenyls and other substances of high molecular mass, using diphenylic ether as solvent. The method has been applied to the main possible coolants for the DON reactor. (author)