Thermal degradation behaviour of flame retardant unsaturated polyester resins incorporating functionalised nanoclays

This paper discusses the effect of nanoclays on thermal degradation of unsaturated polyester resin with and without conventional flame retardants. Unsaturated polyester nanocomposites were prepared by in-situ polymerization with exfoliated structures. Simultaneous DTA-TGA analysis showed that nanoclays reduce thermal stability of the unsaturated polyester resin below 6000C and after that there was no change. Nanoclays also reduce the onset of degradation temperature of the resin. Above 600 0C, char formation is enhanced but not to the same extent as reported in literature for other polymer (e.g., nylon, polystyrene, etc.) – nanocomposite structures. The effect of conventional flame retardants - ammonium polyphosphate, melamine phosphate with and without dipentaeythritaol and alumina trihydrate on thermal degradation of resin was also studied. All these flame retardants enhance char formation of the resin above 4000C and presence of nanoclays promotes further increase. Analysis of the thermogravimetric data indicates that this enhancement in char formation is not as much as expected when compared with similar other polymer - nanocomposite structures

Development of diamond tracking detectors for high luminosity experiments at the LHC

Tracking detectors have become an important ingredient in high energy physics experiments. In order to survive the harsh detection environment of the LHC, trackers need to have special properties. They must be radiation hard, provide fast collection of charge, be as thin as possible and remove heat from readout electronics. The unique properties of diamond allow it to fulfil these requirements. Further, recent progress in the production of chemical vapour deposited diamond makes large surface area detectors now realistic. We propose a development programme which improves the charge collection properties of diamond, studies the radiation hardness of the material, designs various tracking devices, develops low noise, radiation hard electronics to read out the detectors and applies diamond as a thermal management tool for the LHC

Banco público de células de cordão umbilical – BPCCU

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Surface modification of fabrics for improved flash‐fire resistance using atmospheric pressure plasma in the presence of a functionalized clay and polysiloxane

Improving flash fire resistance of otherwise flame resistant fabrics is a recognised challenge within the civil emergency and defence communities. Simulation of the flash fire condition using cone calorimetry has demonstrated the effectiveness of atmospheric plasma treatments in which either a functionalised nanoclay, a polysiloxane (poly(hexamethyldisiloxane)) or both are deposited on to plasma-activated fibre surfaces. Textile substrates comprised flame retardant (Proban®) cotton and a poly (meta-aramid) (Nomex®). Results show that the generated surface layer has a measurable effect on fabric ignition and burning characteristics when exposed in a cone calorimeter at heat flux levels up to 70 kW/m2. Reductions in peak heat release (PHRR) values are observed for all substrates especially for argon/clay and argon/clay/polysiloxane, plasma-treated samples, with reductions of over 50% being observed for Proban® cotton and smaller reductions (≤ 20%) for Nomex® fabrics. Both scanning electron microscopic and cone calorimetric studies show that these properties are retained after a simulated washing process including the argon/clay plasma-treated Proban® and Nomex® fabrics in which no potentially binding polysiloxane was present. This suggests that plasma-activated fibre surfaces in the presence of a functionalised clay enables relatively strong binding forces to be generated. The results provide further evidence in addition to our earlier reported studies, that atmospheric plasma treatment of fabric surfaces in the presence of a nanoclay produces an inorganic coating that confers reduced flammability at the high heat fluxes used suggesting increased resistance to flash fire ignition

Revealing cytotoxic substructures in molecules using deep learning

In drug development, late stage toxicity issues of a compound are the main cause of failure in clinical trials. In silico methods are therefore of high importance to guide the early design process to reduce time, costs and animal testing. Technical advances and the ever growing amount of available toxicity data enabled machine learning, especially neural networks, to impact the field of predictive toxicology. In this study, cytotoxicity prediction, one of the earliest handles in drug discovery, is investigated using a deep learning approach trained on a highly consistent in-house data set of over 34,000 compounds with a share of less than 5% of cytotoxic molecules. The model reached a balanced accuracy of over 70%, similar to previously reported studies using Random Forest. Albeit yielding good results, neural networks are often described as a black box lacking deeper mechanistic understanding of the underlying model. To overcome this absence of interpretability, a Deep Taylor Decomposition method is investigated to identify substructures that may be responsible for the cytotoxic effects, the so-called toxicophores. Furthermore, this study introduces cytotoxicity maps which provide a visual structural interpretation of the relevance of these substructures. Using this approach could be helpful in drug development to predict the potential toxicity of a compound as well as to generate new insights into the toxic mechanism. Moreover, it could also help to de-risk and optimize compounds

Discrimination of natural colors in anomalous trichromacy and the effects of EnChroma and Vino filters

It is still unclear how well anomalous trichromats discriminate natural colors and whether commercial spectral filters improve performance in these conditions. We show that anomalous trichromats have good color discrimination with colors drawn from natural environments. It is only about 14% poorer, on average, than normal trichromats in our sample of thirteen anomalous trichromats. No measurable effect of the filters on discrimination was found, even after 8 hours of continuous use. Computations of cone and post-receptoral signals show only a modest increase in medium-to-long-wavelength difference signals, which may explain the absent effect of the filters.Fundação para a Ciência e a Tecnologia (UIDB/FIS/04650/2020); Fundação para a Ciência e a Tecnologia/Fundo Social Europeu (2020.05785.BD