Conducting Studies of the Am-241 Radionuclide Incorporated into the Human Body Using a Wound Detector

Purpose: to develop a method for experimental study of the distribution of radionuclide 241Am in human organs and tissues during wound admission to clarify the process of formation of doses of alpha radiation. Material and methods: in clinical practice of Burnazyan FMBC of the FMBA of Russia To improve the method of determination, an experiment was performed to determine the depth of radionuclide on pigskin with the location of 241Am point sources behind different thicknesses. Results: the used methods of measurement, tested on pigskin, allowed to obtain the dependence of the localization depth of radionuclide 241Am on the measured on the surface of the tissue ratios of photons with different energies. Conclusion: Set the ratio of photons with different energies on the thickness of the barrier (depth), and proven methodology allow you to go directly to the planning of experimental studies on the barrier effect created in the bone material, and including a radionuclide, the formation of doses of alpha radiation on the bone marrow.

A preliminary exploration of the micro-scale behaviour of capillary barrier effect using microfluidics

Capillary barrier effect (CBE) is employed in a large number of geotechnical applications to decrease deep percolation or increase slope stability. However, the micro-scale behaviour of CBE is rarely investigated, and thus hampers the scientific design of capillary barrier systems. This study uses microfluidics to explore the micro-scale behaviour of CBE. Capillarity-driven water flow processes from fine to coarse porous media with different pore topologies and sizes were performed and analysed. The experimental results demonstrate that the basic physics of CBE is the preferential water movement into the fine porous media due to the larger capillarity. The effects of CBE on water flow processes can be identified as delaying the occurrence of breakthrough into the coarse porous media and increasing the water storage of the fine porous media. The CBE can impede the increase of the normalized length and decrease the normalized width of the water front, suggesting that the two normalized parameters are potential indicators to assess the performance of CBE at micro scale. CBE can be formed in square and honeycomb networks with the ratio of coarse to fine pore throat width larger than 2.0 when gravity is neglected, and its performance can be affected by pore topology and size.

Peanut Shell Derived Carbon Combined with Nano Cobalt: An Effective Flame Retardant for Epoxy Resin

Biomass-derived carbon has been recognised as a green, economic and promising flame retardant (FR) for polymer matrix. In this paper, it is considered that the two-dimensional (2D) structure of carbonised peanut shells (PS) can lead to a physical barrier effect on polymers. The carbonised sample was prepared by the three facile methods, and firstly adopted as flame retardants for epoxy resin. The results of thermal gravimetric analysis (TGA) and cone calorimeter tests indicate that the carbon combined with nano Cobalt provides the most outstanding thermal stability in the current study. With 3 wt.% addition of the FR, both peak heat release rate (pHRR) and peak smoke production rate (PSPR) decrease by 37.9% and 33.3%, correspondingly. The flame retardancy mechanisms of the FR are further explored by XPS and TG-FTIR. The effectiveness of carbonised PS can be mainly attributed to the physical barrier effect derived by PS’s 2D structure and the catalysis effect from Cobalt, which contribute to form a dense char layer.

Effect of Nano Hydrotalcite on the Aging Resistance of a High Binder Content Stone Mastic Asphalt

Hydrotalcite, a type of layered double hydroxide (LDH), reveals an interesting potential for the modification of bitumen. The LDH can induce a barrier effect that prevents the loss of volatiles, retards oxidation, and protects against ultraviolet radiation. Such properties can enhance the aging resistance of the bitumen. However, there is a gap in knowledge regarding the effects of the modification with hydrotalcite in the properties of the asphalt mixture. To contribute to fill such a gap, the current study presents a characterization of the effects of the modification with nano hydrotalcite in the surface characteristics, mechanical performance, and aging resistance of an asphalt mixture. To better explore the effects of the modification, the selected asphalt mixture was a high binder content (7.5%) Stone Mastic Asphalt (SMA). The experimental study indicates that the binder-rich SMA presented adequate performance for application in surface courses. If compared to conventional mixtures, the binder-rich SMA presented better initial mechanical performance (unaged conditions). Furthermore, it presented smaller variation in the parameters between unaged and aged conditions, indicating enhanced aging resistance. The modification with nano hydrotalcite induced smaller evolution in the fatigue resistance parameters, indicating enhanced aging resistance; however, in the remaining tests, the trends were not clear.

Anti-adhesive membranes based on crosslinked carboxymethyl cellulose

In recent times, new anti-adhesion devices including devices based on carboxymethyl cellulose (CMC), which have “barrier” effect are being developed and actively introduced into surgical practice. The “barrier” should be completely resorbed after the time required to healing the morphofunctional integrity of the injured peritoneum, be economically available and easy to use (including laparoscopic technologies). But the time when the CMC is in the body is insufficient to prevent the formation of adhesions, particularly in the presence of non-absorbable rigid implants. The reactive functional groups in CMC allow to transform the CMC-macromolecule into a spatial structure. For this are required the using of bifunctional (bicarboxylic or aminocarboxylic) acids and the transform of a part of the carboxyl groups from the Na-form to the hardly soluble H-form, i.e., it is necessary to crosslink CMC-macromolecules. Adipic acid and glutaric acid, aminoacetic acid and amino capronic acid used are linking agents. The influence of modification parameters on the degree of polymers swelling in water is studied. As a result, to obtain membranes designed for the treatment of adhesive disease, it is recommended to use additives in CMC of bifunctional compounds.