Mean field approximation and ab initio calculation of magnetic and optical properties of DyN doped with transition metals (TM: V and Cr)

The structural, optical, and magnetic properties of rare earth nitride \(\hbox {Dy}_{0.95}\hbox {TM}_{0.05}\hbox {N}\) (TM: V and Cr) diluted magnetic semiconductors have been investigated using the Korringa–Kohn–Rostoker method combined with the coherent potential approximation. In this work, the effect of GGA–SIC approximations on the electronic properties was investigated in detail. It is revealed from calculating the density of states (DOS) and optical absorption spectra that the ferromagnetic state is stable when TM introduces magnetic moments in \(\hbox {Dy}_{0.95}\hbox {TM}_{0.05}\hbox {N}\) (TM: V and Cr). Using the mean field approximation (MFA), the Curie temperature is determined by the total energy difference per V and Cr atoms between the disorder local moment (DLM) and ferromagnetic (FM) state within the ambient conditions, which becomes more important by increasing the concentration or by co-doping (V, Cr) DyN systems.     

Algorithm for Computing Bernstein–Sato Ideals Associated with a Polynomial Mapping

Let f₁, . . . , f_pbe polynomials in n variables with coefficients in a fieldK. We associate with these polynomials a number of functional equations and related ideals B, B_jand BΣ ofK[ s₁, . . . , s_p] called Bernstein–Sato ideals. Using standard basis techniques, our aim is to present an algorithm for computing generators of B_jand BΣ.     

Isolation and characterization of bacterial strains capable of growing on malathion and fenitrothion and the use of date syrup as an additional substrate

Four bacterial strains capable of growing on two organophosphorus pesticides (malathion and fenitrothion) were isolated from activated sludge. Among these isolates, the species Stenotrophomonas maltophilia was found to be capable of using fenitrothion as the sole carbon and nitrogen source, and malathion as the sole carbon source. There appear to be no similar reported findings. A crude juice of dates was tested as an additional carbon source for malathion degradation. The biodegradability was significantly enhanced with the supplementation of date juice. The degradation efficiency of the pesticide tested at a concentration of 60 mg/L reached the maximum value of 89% in the presence of date juice at 30 g/L reducing sugar. Statistical screening of four operating parameters (initial biomass concentration, aeration rate, agitation and temperature) for biomass growth and for malathion degradation by acclimated indigenous activated sludge was carried out using a fractional factorial design.