Nuclear matrix element for two neutrino double beta decay from 136Xe

The nuclear matrix element for the two neutrino double beta decay (DBD) of 136Xe was evaluated by FSQP (Fermi Surface Quasi Particle model), where experimental GT strengths measured by the charge exchange reaction and those by the beta decay rates were used. The 2 neutrino DBD matrix element is given by the sum of products of the single beta matrix elements via low-lying (Fermi Surface) quasi-particle states in the intermediate nucleus. 136Xe is the semi-magic nucleus with the closed neutron-shell, and the beta + transitions are almost blocked. Thus the 2 neutrino DBD is much suppressed. The evaluated 2 neutrino DBD matrix element is consistent with the observed value.Comment: 7 pages 6 figure

Efficacy of atmospheric pressure dielectric barrier discharge for inactivating airborne pathogens

Atmospheric pressure plasmas have gained attention in recent years for several environmental applications. This technology could potentially be used to deactivate airborne microorganisms, surface-bound microorganisms, and biofilms. In this work, the authors explore the efficacy of the atmospheric pressure dielectric barrier discharge (DBD) to inactivate airborne Staphylococcus epidermidis and Aspergillus niger that are opportunistic pathogens associated with nosocomial infections. This technology uses air as the source of gas and does not require any process gas such as helium, argon, nitrogen, or hydrogen. The effect of DBD was studied on aerosolized S. epidermidis and aerosolized A. niger spores via scanning electron microscopy (SEM). The morphology observed on the SEM micrographs showed deformations in the cellular structure of both microor- ganisms. Cell structure damage upon interaction with the DBD suggests leakage of vital cellular materials, which is a key mechanism for microbial inactivation. The chemical structure of the cell surface of S. epidermidis was also analyzed by near edge x-ray absorption fine structure spectros- copy before and after DBD exposure. Results from surface analysis revealed that reactive oxygen species from the DBD discharge contributed to alterations on the chemistry of the cell membrane/ cell wall of S. epidermidis

Catalytic-Dielectric Barrier Discharge Plasma Reactor For Methane and Carbon Dioxide Conversion

A catalytic - DBD plasma reactor was designed and developed for co-generation of synthesis gas and C2+ hydrocarbons from methane. A hybrid Artificial Neural Network - Genetic Algorithm (ANN-GA) was developed to model, simulate and optimize the reactor. Effects of CH4/CO2 feed ratio, total feed flow rate, discharge voltage and reactor wall temperature on the performance of catalytic DBD plasma reactor was explored. The Pareto optimal solutions and corresponding optimal operating parameters ranges based on multi-objectives can be suggested for catalytic DBD plasma reactor owing to two cases, i.e. simultaneous maximization of CH4 conversion and C2+ selectivity, and H2 selectivity and H2/CO ratio. It can be concluded that the hybrid catalytic DBD plasma reactor is potential for co-generation of synthesis gas and higher hydrocarbons from methane and carbon dioxide and showed better than the conventional fixed bed reactor with respect to CH4 conversion, C2+ yield and H2 selectivity for CO2 OCM process

Recent advances in neutrinoless double beta decay search

Even after the discovery of neutrino flavour oscillations, based on data from atmospheric, solar, reactor, and accelerator experiments, many characteristics of the neutrino remain unknown. Only the neutrino square-mass differences and the mixing angle values have been estimated, while the value of each mass eigenstate still hasn't. Its nature (massive Majorana or Dirac particle) is still escaping. Neutrinoless double beta decay ($0\nu$-DBD) experimental discovery could be the ultimate answer to some delicate questions of elementary particle and nuclear physics. The Majorana description of neutrinos allows the $0\nu$-DBD process, and consequently either a mass value could be measured or the existence of physics beyond the standard should be confirmed without any doubt. As expected, the $0\nu$-DBD measurement is a very difficult field of application for experimentalists. In this paper, after a short summary of the latest results in neutrino physics, the experimental status, the R&D projects, and perspectives in $0\nu$-DBD sector are reviewed.Comment: 36 pages, 7 figures, To be publish in Czech Journal of Physic

Electronic properties of very thin native SiO2/a-Si:H interfaces and their comparison with those prepared by both dielectric barrier discharge oxidation at atmospheric pressure and by chemical oxidation

The contribution deals with electronic properties of thin oxide/amorphous hydrogenated silicon (a-Si:H) measured by capacitance-voltage (C-V) and charge version of deep level transient spectroscopy (Q-DLTS). The interest was focused on the studies of the interface properties of very thin dielectrics formed by dielectric barrier discharge (DBD) or natively on the a-Si:H layer. These properties were compared with those of oxide layers prepared by chemical oxidation in HNO3. The DBD was used for the preparation of a very thin SiO2 layer on a-Si:H for the first time to our knowledge. Preliminary electrical measurements confirmed that a very low interface states density was detected in the case of the native oxide/a-Si:H and DBD oxide/a-Si:H

Chemical modification of extracellular matrix by cold atmospheric plasma-generated reactive species affects chondrogenesis and bone formation.

The goal of this study was to investigate whether cold plasma generated by dielectric barrier discharge (DBD) modifies extracellular matrices (ECM) to influence chondrogenesis and endochondral ossification. Replacement of cartilage by bone during endochondral ossification is essential in fetal skeletal development, bone growth and fracture healing. Regulation of this process by the ECM occurs through matrix remodelling, involving a variety of cell attachment molecules and growth factors, which influence cell morphology and protein expression. The commercially available ECM, Matrigel, was treated with microsecond or nanosecond pulsed (μsp or nsp, respectively) DBD frequencies conditions at the equivalent frequencies (1 kHz) or power (~1 W). Recombinant human bone morphogenetic protein-2 was added and the mixture subcutaneously injected into mice to simulate ectopic endochondral ossification. Two weeks later, the masses were extracted and analysed by microcomputed tomography. A significant increase in bone formation was observed in Matrigel treated with μsp DBD compared with control, while a significant decrease in bone formation was observed for both nsp treatments. Histological and immunohistochemical analysis showed Matrigel treated with μsp plasma increased the number of invading cells, the amount of vascular endothelial growth factor and chondrogenesis while the opposite was true for Matrigel treated with nsp plasma. In support of the in vivo Matrigel study, 10 T1/2 cells cultured in vitro on μsp DBD-treated type I collagen showed increased expression of adhesion proteins and activation of survival pathways, which decreased with nsp plasma treatments. These results indicate DBD modification of ECM can influence cellular behaviours to accelerate or inhibit chondrogenesis and endochondral ossification. Copyright © 2016 John Wiley & Sons, Ltd