Miscibility and thermal behavior of poly(methyl methacrylate) and polystyrene blend using benzene as a common solvent.

Polymer blending is one of the advanced technologies to attain polymeric material with tailored properties. In this work, the miscibility of Poly(methyl methacrylate) (PMMA) and Polystyrene (PS) blend in benzene was investigated by employing various techniques such as FTIR spectroscopy, viscosity measurement technique, light scattering techniques, DSC and TGA techniques over an extended range of concentrations, compositions, and temperatures. The results revealed that there exist hydrogen bonding and hydrodynamic interactions which led these polymers to get miscible to a large extent. The compatibility increased with the increasing PS contents or increase in temperature of the system. In addition, the thermal stability of blends was found to be improved with the increase in the compatibility of the polymer.

Microbiome of Pukzing Cave in India shows high antimicrobial activity against plant and animal pathogens.

Pukzing cave, the largest cave of Mizoram, India was explored for bacterial diversity. Culture dependent method revealed 235 bacterial isolates using three different treatments. Identity of the microbial species was confirmed by 16S rDNA sequencing. The highest bacterial population was recovered from heat treatment (n = 97;41.2%) followed by normal (n = 79;33.6%) and cold treatment (n = 59;25.1%) indicating dominance of moderate thermophiles. Antimicrobial potential of isolates showed 20.4% isolates having antimicrobial ability against tested pathogens. Amplicon sequencing of PKSI, PKSII and NRP specific genes revealed presence of AMP genes in the microbial population. Six microbial pathogens were selected for screening as they are well known for different disease cause organism in various fields such as agriculture and human health. Cave environment harbors unique microbial flora and hypervariable region V4 is more informative. Higher activity of AMP assay against these microbes indicates that cave microbial communities could be potential source of future genomic resources.

A simulation study on angular and micro pattern effects in GEM detectors.

A useful approach for the enhancement of thermal neutrons detection has been reported here. This technique, based on the angular and micro pattern effects, has been developed and applied to the boron-coated ((10)B) Gas Electron multiplier (GEM) detector. In the angular effect case, as a general rule, the detector device is turned at an angle which improves the device response per unit area of the detector. While for the latter case, a regular pattern in the form of micrometer deep grooves is fabricated onto the converter coating, consequently it enhances the capture probability of the detector. For the current study, both of these techniques using a (10)B-coated GEM detector have been simulated for low energy neutrons. For the evaluation of detector response thermal neutrons in the energy ranges from 25meV to 100meV were transported onto the detector surface. For this work, FLUKA MC code has been utilized. The output in both cases has been estimated as a function of incident thermal neutron energies. By employing both techniques, the angle and the micro pattern dependent efficiencies for (10)B-coated GEM detectors are presented, which indicate an improved efficiency response of the device. We anticipate that by using these modifications can lead a further forward step in the development and improvement of thermal neutron detection technology.

Thermal neutron response of a boron-coated GEM detector via GEANT4 Monte Carlo code.

In this work, we report the design configuration and the performance of the hybrid Gas Electron Multiplier (GEM) detector. In order to make the detector sensitive to thermal neutrons, the forward electrode of the GEM has been coated with the enriched boron-10 material, which works as a neutron converter. A total of 5×5cm2 configuration of GEM has been used for thermal neutron studies. The response of the detector has been estimated via using GEANT4 MC code with two different physics lists. Using the QGSP_BIC_HP physics list, the neutron detection efficiency was determined to be about 3%, while with QGSP_BERT_HP physics list the efficiency was around 2.5%, at the incident thermal neutron energies of 25meV. The higher response of the detector proves that GEM-coated with boron converter improves the efficiency for thermal neutrons detection.