Neutrino mass, leptogenesis and sterile neutrino dark matter in inverse seesaw framework

We study [Formula: see text] flavor symmetric inverse seesaw model which has the possibility of simultaneously addressing neutrino phenomenology, dark matter (DM) and baryon asymmetry of the universe (BAU) through leptogenesis. The model is the extension of the standard model by the addition of two (RH) neutrinos and three sterile fermions leading to a keV scale sterile neutrino DM and two pairs of quasi-Dirac states. The CP violating decay of the lightest quasi-Dirac pair present in the model generates lepton asymmetry which then converts to BAU. Thus, this model can provide a simultaneous solution for nonzero neutrino mass, DM content of the universes and the observed baryon asymmetry. The [Formula: see text] flavor symmetry in this model is augmented by additional [Formula: see text] symmetry to constrain the Yukawa Lagrangian. A detailed numerical analysis has been carried out to obtain DM mass, DM-active mixing as well as BAU both for normal hierarchy as well as inverted hierarchy. We try to correlate the two cosmological observables and found a common parameter space satisfying the DM phenomenology and BAU. The parameter space of the model is further constrained from the latest cosmological bounds on the observables.

Leptonic anomalous magnetic moments in ν SMEFT

We investigate contributions to the anomalous magnetic moments of charged leptons in the neutrino-extended Standard Model Effective Field Theory (νSMEFT). We discuss how νSMEFT operators can contribute to a lepton’s magnetic moment at one- and two-loop order. We show that only one operator can account for existing electronic and muonic discrepancies, assuming new physics appears above 1 TeV. In particular, we find that a right-handed charged current in combination with minimal sterile-active mixing can explain the discrepancy for sterile neutrino masses of $$ \mathcal{O} $$ O (100) GeV while avoiding direct and indirect constraints. We discuss how searches for sterile neutrino production at the (HL-)LHC, measurements of h→μ+μ− and searches for h→e+e−, neutrinoless double beta decay experiments, and improved unitarity tests of the CKM matrix can further probe the relevant parameter space.

$$3+1$$ active–sterile neutrino mixing in $$B-L$$ model with $$S_{3}{\times Z_4\times Z_2}$$ symmetry for normal neutrino mass ordering

We propose a non-renormalizable $$B-L$$ B - L model with $$S_{3}{\times Z_4\times Z_2}$$ S 3 × Z 4 × Z 2 symmetry which successfully accommodates the current active–sterile neutrino mixing in $$3+1$$ 3 + 1 scheme. The $$S_3$$ S 3 flavor symmetry is supplemented by $$Z_4\otimes Z_2$$ Z 4 ⊗ Z 2 symmetry to consolidate the Yukawa interaction of the model. The presence of $$S_3\otimes Z_4\otimes Z_2$$ S 3 ⊗ Z 4 ⊗ Z 2 flavour symmetry plays an important role in generating the desired structure of the neutrino mass matrix. The model can reproduce the recent observed active-neutrino neutrino oscillation data for normal ordering in which two sterile–active mixing angles $$\theta _{14, 24}$$ θ 14 , 24 get the best-fit values and the obtained values of $$\theta _{34}, \delta _{14}, \delta _{14}$$ θ 34 , δ 14 , δ 14 , the sum of neutrino mass and the effective neutrino masses are within their currently allowed ranges.

Microextraction of lanthanum using a rotating microchannel extractor

This work introduced a novel microchannel extractor. The extraction system was to extract lanthanum nitrate aqueous solution with 2-ethylhexyl phosphoric acid-2-ethylhexyl ester (EHEHPA). Different feeding methods and inner rotors were explored first. The results showed that parallel feeding and inner rotors engraved with spiral stripes were more favorable for extraction. Next, the effect of various factors on the extraction was explored, including the pH of the aqueous phase, rotational inner rotor speed (R) and the fluid volumetric flow rate (Q). The results showed that these factors are closely related to the extraction. Finally, the experiment was verified by CFD numerical simulation, the simulation result was consistent with the experiment. In this device, active mixing was introduced into the microchannel extraction, which significantly improved the extraction efficiency. Under certain conditions, the extraction efficiency of this device exceeded stirring extraction equilibrium. Moreover, the extraction in this device is faster than conventional stirring extraction. These advantages provide a possibility for highly efficient extraction and use of rare earth elements.

Perforated Baffles for the Optimization of Disinfection Treatment

Water disinfection is one of the main treatments aimed at maintaining human health. Traditionally, the treatment takes place inside multichamber tanks that facilitate the contact between disinfectant and pathogenic microorganisms to be removed. However, the traditional contact tanks used for disinfection have geometric characteristics causing the formation of dead or recirculation zones that reduce treatment efficiency with potentially harmful effects on human health. This study proposes the creation of holes in the baffles that divide the various chambers in order to increase the mixing inside the reactor. In particular, various configurations with holes of different sizes were considered. The results obtained through fluid dynamics simulations based on the LES (large eddy simulation) model show that the jet emerging from the holes penetrates the recirculation zones, transforming them into areas of active mixing. The analysis of the hydraulic mixing indices traditionally used to evaluate the performance of these tanks shows that the presence of the holes allows a significant increase in the mixing efficiency by reducing the short-circuit phenomena and the entrapment of the disinfectant inside the dead zones. Parameters of fundamental importance are the size of the holes, the arrangement of the holes within the baffles and the perforation percentage.

A Perforated Baffle Design to Improve Mixing in Contact Tanks

In this study, a perforated baffle design is proposed to improve mixing in contact tanks. Turbulent flow through the perforated baffle is studied at the perforation hole scale. The contribution of jets emerging from the perforations to the mixing process is evaluated in terms of standard mixing indexes for various perforation parameters, such as the solidity ratio and hole diameter. Based on numerical simulation results, the two sets of perforated baffles that yielded the highest performance were manufactured from polycarbonate and tracer studies were conducted on a laboratory model. Comparison of numerical and experimental results demonstrates that the numerical model developed is reliable in simulating the flow through the perforated baffles and the associated mixing level in the contact tank. Numerical simulations indicate that the jet flow structure through the perforated baffle penetrates to the recirculation zones in the neighboring chambers and turns the dead zones into active mixing zones. Furthermore, large scale turbulent eddies shed by the perforations contribute to the mixing process in the chambers of the tank. With the use of the perforated baffle design, it is shown that the hydraulic efficiency of the tank can be improved from average to superior according to the baffling factor, and the associated mixing in the proposed design can be improved by 31% according to the Morrill index.