Cosmological Model in Four Time and Four Space Dimensions

We develop a cosmological model in a physical background scenario of four time and four space dimensions ((4+4)-dimensions or (4+4)-universe). We show that in this framework the (1+3)-universe is deeply connected with the (3+1)-universe. We argue that this means that in the (4+4)-universe there exists a duality relation between the (1+3)-universe and the (3+1)-universe.

Microbial oxidation of refractory gold sulfide concentrate by a native consortium

A defined mesophilic consortium including an iron oxidizing bacterium and a sulfur oxidizing bacterium was constructed to evaluate its ability for bioleaching a flotation concentrate from Andacollo mine in Neuquén,Argentina.Experiments were performed in shake flasks with a pulp density of10%(w/v),using a basal salt medium containing ferrous iron at pH1.8.The leaching solutions were analyzed for pH,redox potential(using specifics electrodes),ferrous iron(by UV-Vis spectrophotometry)and metal concentrations(by atomic absorption spectroscopy).The results showed that the consortium was able to reduce the refractory behavior of the concentrate,allowing91.6%of gold recovery;at the same time,high dissolution of copper and zinc was reached.These dissolutions followed a shrinking core kinetic model.According to this model,the copper solubilization was controlled by diffusion through a product layer(mainly jarosite),while zinc dissolution did not show a defined control step.This designed consortium,composed of bacterial strains with specific physiological abilities,could be useful not only to optimize gold recovery but also to decrease the leachates metallic charge,which would be an environmental advantage.

Effect of Nanoparticles on Mechanical Properties of Cement-Sand Mortar Applications

Cement-sand mortar is a construction material widely used;tile adhesive is one of the main applications where the compressive strength is the key performance metric. Nanoparticles like MWCNTs and HNTs are currently being used to improve the mechanical performance of the cement mortar due to their properties. The cost of MWCNTs has limited their application in the construction industry. This study focuses on the effect of two different concentrations of MWCNTs and HNTs in cement mortar;HNTs are proposed in this study to compare performance and cost overall benefits. A common problem with MWCNTs is agglomeration;to achieve a proper dispersion an ultrasonic processor was utilized. Mechanical properties of a cement mortar modified with nanoparticles were investigated with compression and bending tests on specimens performed at the age of 7 days. Results showed that concentrations of 0.1% of MWCNTs increase in compression strength by 56% and concentrations of 0.1% of HNTs performance increased by 31%, both compared to plain cement mortar.

Description of New Bioelectromechanical Properties in Alginate: An Insight with a Computer Simulation

Alginate biopolymer from Tropicalgin C302245 was studied by means of piezoresponse force microscopy imaging, scanning electron microscopy, powder X-rays, infrared spectroscopy and computer simulations. Local piezoresponse force microscopy images show possible ferroelectric domains detected in the out of plane mode and these results are confirmed by the second harmonic generation analysis. Alginate powder is composed by diatom frustules containing a cristobalite-like compound, amorphous silica and chitin. The experimental results are explained by MM+ and PM3 computer simulations that establish that the self-assembly of the alginate molecules enhance the polarization increasing the molecular collective dipole moment. Alginate molecular properties might open interesting possibilities for organic technological applications.

Cosmological Duality in Four Time and Four Space Dimensions

We describe a duality transformation in a cosmological model of four time and four space dimensions ((4 + 4)-dimensions). In particular, we show that via the Fourier transform, at the level of the zero-point energy of quantum mechanics and the de Sitter space, a Gaussian distribution in four dimensions leads to a dual Gaussian distribution also in four dimensions, with duality transformation , in the standard deviation σ. Moreover, we show that as a consequence of such a duality in σ a duality of the cosmological constant Λ can be obtained. Finally, we comment on the possibility that both the oriented matroid theory as well as the surreal number theory are related to the formalism presented in this work.

On α-Weyl Operators

The purpose of this article is to present Schechter’s manner to introduce α-Wayl operators and compare this definition with another one given by Yadav and Arora. Moreover, we introduce generalized Weyl operator in the way that we keep many properties of the class of Weyl operators.

A private SUSY 4HDM with FCNC in the up-sector

We present a SUSY model with four Higgs doublets of the"private type,"in which all fermion types(up,down,and charged leptons)obtain their masses from a different Higgs doublet H_f(f=u_1,d,e) .The conditions for anomaly cancellation imply that the remaining Higgs doublet of the model( H_(u_2) )must have the same hypercharge as H_(u_1) ,and thus,can only couple to up-type quarks,which opens the possibility to have FCNCs only in this sector.We study the Lagrangian of the model,and in particular,the Higgs potential,to identify the Higgs mass-eigenstates and their interactions;for the Yukawa matrices,we consider the four-texture case.We obtain constraints on the model parameters by using LHC measurements on the properties of the 125 GeV Higgs boson(h),and identify viable regions of the parameter space.Subsequently,these constraints are used to evaluate the prospects for detecting the FCNC decay mode t→ch at the future high-luminosity(HL)option for the LHC,which are compared with current limits from LHC-run2.Moreover,we evaluate the FCNC decay of the next heavier Higgs boson H_(2)→tc ,which can typically reach BR(H_2→tc)≈(10^(-4)-10^(-5)) .The search for the signal at HL-LHC is also studied,and it is found that it may be detectable for specific regions of the model parameter space.