[en] Independent external dosimetry audit plays a crucial role in ensuring the quality and accuracy of radiotherapy treatments of individual institution. An ABS cuboid phantom was designed, fabricated and used for conducting dosimetry audit of advanced radiotherapy. ABS cuboid phantom proved to be useful for dosimetry audit in advanced radiotherapy techniques. The phantom can facilitate end-to-end verification of radiotherapy, encompassing imaging, planning, and delivery processes. Moreover, developed phantom and methodology may also be useful for establishing a national dosimetry audit network in India

[en] Elastomers based on butadiene-nitrile rubbers (NBR) are widely used in the petroleum and petrochemical industries as a seal and insulation. Therefore, it is reasonable that for a long maintenance interval will need sealing materials that have little change in properties whether by thermal or chemical processes throughout the service life of the seal. This work aims at clarifying the possibility of improving the technical properties of radiation and thermo-radiation vulcanizations by introducing into the formulation as an activator of zinc nano-oxide, as a sensitizer 2, 4-diamino-6-phenyl si mm triazine (DAPhST), as a crosslinking agent 1, 3-dichlorophos benzene (DSCB), contributing to the acceleration of radiation-chemical reactions in the elastomer.

[en] The special case of the (p + 1)th degree algebraic equations of the kind x ^p+1 = x ^p + 1 (p = 1, 2, 3, ?) is researched in the present article. For the case p = 1, the given equation is reduced to the well-known Golden Proportion equation x ² = x + 1. These equations are called the golden algebraic equations because the golden p-proportions τ _p, special irrational numbers that follow from Pascal's triangle, are their roots. A research on the general properties of the roots of the golden algebraic equations is carried out in this article. In particular, formulas are derived for the golden algebraic equations that have degree greater than p + 1. There is reason to suppose that algebraic equations derived by the authors in the present article will interest theoretical physicists. For example, these algebraic equations could be found in the research of the energy relationships within the structures of many compounds and physical particles. For the case of butadiene (C₄H₆), this fact is proved by the famous physicist Richard Feynman

[en] Research project, carbon blacks were produced by furnace (S324) and channel(K354) methods were added to elastomer mixture and vulcanization process carried out with gamma rays and physical chemical properties are learned. Two types of fillers with different amounts were included to composite material which formed by based on butadiene nitrile rubber nano zinc oxide particles and disulphurchloridebenzyl used as crosslinking agent. The obtained mixture was vulcanized by 250 kGr gamma rays. It is shown that, strength, hardness and the stiffness of vulcanized materials are causes to change the physical-mechanical properties. Moreover, impact of the amount and type of filler. According to the influence of the elastomer mixed with fillers improves the yield amount of carbon-rubber gels (CRG)

[en] Full text: Acrylonitrile-butadiene elastomers (NBR) are widely used on the oil and automotive industries in hoses, sealing rings, gaskets, fuel pipes, and many other rubber products due to its good resistance to oil, apolar solvents and temperature. However, a NBR artifact needs to be vulcanized and reinforced with fillers in order to present those good properties. Carbon black is the most well-known and used filler for rubber, however other types of filler such as short length fibers are subject of recent studies. This study assesses different types of rock wool fibers (RWF) with different lengths; 100 μm and 300 μm, with and without surface chemical modification on NBR composites using X-ray computed tomography. The scans were carried out in a Bruker SkyScan 2211 multiscale Nano-CT with a 0.9 μm pixel size. Nine formulations with 10, 25 and 40 parts per hundred rubber (phr) of 03 different RWF types were prepared in a standard two-roll mixer based on the parameters described on ASTM D-3187. After the mixing procedures, rubber compounds were left 24 hours in a room with 23 ± 2 °C and moisture not higher than 50% to rest. Afterwards the compounds were vulcanized in a hydraulic press at 160 °C, 180 kgf/cm², using the optimum cure time (t90) obtained through their rheometric characteristics as time parameter (ASTM D-2084). The X-ray computed tomography analysis allowed us to evaluate three major parameters. The arrangement of the fibers in the rubber matrix, exposing whether a preferential orientation was achieved, the fiber volume fraction actually dispersed in the rubber matrix, and the aspect ratio (length/diameter) of the fibers, which is important to determine crosslink density using a fast method on a Rubber Process Analyzer instead of a high time consuming swelling test. The Mogno beamline at SIRIUS synchrotron facility will provide faster and more precise measurement with submicrometric resolution, which is essential for the future characterization of our samples. (author)

[en] Catalytic properties of Ni-ZrO_2 catalysts prepared by coprecipitation have been studied for the gas-phase hydrogenation of 1,3-butadiene to butenes. The coprecipitation method led to the solid solution of Ni-ZrO_2, which contains highly resistant Ni species to thermal reduction with H_2. Nickel species of the solid solution were highly dispersed in the ZrO_2 lattice, so that the reduced catalysts were selective for hydrogenation of 1,3-butadiene to butenes (99.9%) even in the presence of 1-butene

[en] The materials obtained on the basis of butadiene nitrile rubber have a wide range of applications due to their superior properties. The subject of the study was a composite material made of butadiene nitrile rubber (SKN 40), containing stearic acid, zinc oxide, diallyl ether of maleic acid (DAEMA) and technical carbon (P324). The investigated composite material was vulcanization using thermal (150 C x 40') and radiation methods (500 kGr). Zol-gel analysis was performed on the system using equal swelling rates and Flory-Rehnar theory. Due to thermal, radiation and thermal radiation processes, the degree of swelling, molecular weight, and the number of grid lines were determined for the processes in the solution and solvent.

[en] A method of photochemical separation of the mercury isotopes by the so-called indirect route in which a gas stream of oxygen and butadiene containing a mixture of mercury isotopes is passed through one or a number of vessels placed in series. The gas stream is irradiated by a lamp containing mercury which is depleted in one or a number of the isotopes and said isotopes are recovered in a trap placed downstream of the vessel or vessels

[en] The hydrogenated acrylonitrile-butadiene rubber, with a thermal stability up to 185 degrees C was subjected to accelerated thermal deflexion, DRC, to 15, 25, 35 and 50% constant deflexion. The irradiation used was Co sources for a dose rate of 4, 11 and 31.6 krad/h, corresponding to 25% constant deflexion. For 15,35 and 50% constant deflexion, the ageing was obtained at the temperature only for the constant deflexion corresponding to 17.1, 6.51, and 2.31 krad/h, adequate to constant deflexion of 15,35 and 50%. Due to the relaxation phenomena which take place in viscoelastic polymers, the agreed mechanisms models gave the material equations which are in very good concordance with the experimental results

[en] The effect of Organo-Chlorine Compounds (OCC) on the radiation structuring of SKN-40 was investigated in filled model systems with 5 mass. h. of ZnO.The content of gel was determined at various dosages of OCC after irradiation with doses from 5 to 40 MRad. With increasing dosages of OCC, it takes part in the formation of rubber. After radiation exposure, the optimal conditions for the content of gel systems are 62-65%, and the activity in the processes of radiation structuring of OCC is located in the same row that was composed of the composition of the heating. The effective concentration of cross-links at optimal dosages of OCC (n'_e 10''-''1''9, cm''-''3) in the optimum vulcanization constitute model systems with HCCP-5,3, adduct 1-5,3, adduct 2-6,3, adduct 3-6,5. In the presence of OCC, the optimal dose of radiation is reduced, so they can be considered as sensitizers of radiation structuring. Thus, it was found that the investigated OCC are effective structuring agents for SKN-40 both during heating and exposure to λ irradiation.