We consider a flavor model based on the ${A}_{4}$ modular group to account for both lepton and quark parameters (masses mixing). The inverse seesaw mechanism is considered produce light neutrino masses. Lepton masses mixing are obtained in terms of Yukawa coupling ratios values modulus $\ensuremath{\tau}$ nearby some fixed points inverted mass hierarchy. arisen at same used hierarchy agreement ...

We study the mechanism by which gravitational actions reproduce the trace anomalies of the holographically related conformal field theories. Two universal features emerge: a) the ratios of type B trace anomalies in any even dimension are independent of the gravitational action being uniquely determined by the underlying algebraic structure b) the normalization of the type A and the overall norm...

This experimental work studies a small-scale biomass combustor (5–12 kW) with an underfed fixed bed using low air staging ratios (15%–30%). This document focuses on the influence of the operative parameters on the combustion process, so gaseous emissions and the distribution and concentration of particulate matter have also been recorded. The facility shows good stability and test repeatability...

[1] Empirical transfer functions are derived for predicting the total benthic nitrate loss (LNO3) and the net loss of dissolved inorganic nitrogen (LDIN) in marine sediments, equivalent to sedimentary denitrification. The functions are dynamic vertically integrated sediment models which require the rain rate of particulate organic carbon to the seafloor (RRPOC) and a proposed new variable (O2-N...

In conventional wastewater treatment, biological nutrient removal (BNR) depends on bacterial assimilation for phosphorus removal and nitrification+denitrification for nitrogen removal, with the resulting loss of the fixed nitrogen resource. Alternatively, treatment by microalgae allows for assimilative removal of both phosphorus (P) and nitrogen (N) thereby avoiding the oxygen demand of nitrifi...

Arpe and Manthey [Algorithmica’09] recently studied the minimum ANDcircuit problem, which is a circuit minimization problem, and showed some results including approximation algorithms, APX-hardness and fixed parameter tractability of the problem. In this note, we show that algorithms via the k-set cover problem yield improved approximation ratios for the minimum AND-circuit problem with maximum...

We study links between approximation, exponential time computation and fixed parameter tractability. In particular, rather than focusing on one particular optimization problem, we tackle the question of finding sufficient conditions for a problem to admit “good” approximation algorithms in exponential time. In particular, we focus on the existence of “approximation schemata” (ratios 1 ± ǫ for a...