Plant‐supported silver nanoparticles: Efficient,economically viable and easily recoverable catalyst for the reduction of organic pollutants

Ginger rhizome powder was used for the synthesis of supported metallic nanoparticle catalysts. A simple and novel adsorption method was used for the synthesis of silver nanoparticles loaded on ginger powder (Ag/GP), copper on ginger powder (Cu/GP) and nickel on ginger powder (Ni/GP). Among these, Ag/GP showed selective reduction of methyl orange and was used for further reactions. The prepared nanomaterials were characterized through X‐ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, fourier transform infrared spectroscopy and energy‐dispersive X‐ray spectroscopy. The prepared Ag/GP catalyst was employed in the catalytic reduction of 4‐nitrophenol (4‐NP), 2‐nitrophenol (2‐NP), rhodamine B, methyl red and congo red. Ag/GP showed excellent catalytic reduction activity, the rate constants being 1.26 × 10^?3 and 2.38 × 10^?3 s^?1 for 2‐NP and 4‐NP, respectively. The turnover frequency reached 1.06 min^?1 for 2‐NP and 1.16 min^?1 for 4‐NP when using the Ag/GP catalyst. The prepared Ag/GP catalyst demonstrated outstanding activity for the degradation of a mixed solution of dyes. Also, stability and reusability of the prepared catalyst were investigated, which showed outstanding reusability up to five times and was stable up to five days.     

Cross-coupling reactions towards the synthesis of natural products

Molecular Diversity - Cross-coupling reactions are powerful synthetic tools for the formation of remarkable building blocks of many naturally occurring molecules, polymers and biologically active...     

Catalytic Reaction of substituted 1,3-oxathiolanes with diazocarbonyl compounds

Chemistry of Heterocyclic Compounds - The reaction of substituted 1,3-oxathiolanes with diazocarbonyl compounds in the presence of Cu(OTf)2 and Rh2(OAc)4 was studied. The reaction is accompanied by...     

Ferromagnetism without flat bands in thin armchair nanoribbons

Describing by a Hubbard type of model a thin armchair graphene ribbon in the armchair hexagon chain limit, one shows in exact terms, that even if the system does not have flat bands at all, at low concentration a mesoscopic sample can have ferromagnetic ground state, being metallic in the same time. The mechanism is connected to a common effect of correlations and confinement.     

Cs2LiGdCl6 (Ce): New scintillation material

We investigated the scintillation properties of Cs₂LiGdCl₆:Ce³⁺ as a function of the Ce concentration. X-ray excited luminescence spectra of the scintillation material showed broad emission bands between 360 and 460 nm, with two overlapping peaks, due to the d→f transitions on Ce³⁺ ions. The samples provide good scintillation results. The energy resolution was found to be 5.0% (FWHM) at 662 keV for 10% Ce sample. Under γ-ray excitation, Cs₂LiGdCl₆:Ce³⁺ showed three exponential decay time components of about 130–200 ns decay time constant. The light output of the investigated samples was 20,000 photons/MeV for a 10% Ce concentration. The light output deviation from the linear response is within 7% between the energy range of 31 and 1333 keV. Overall, the scintillation properties confirm that Cs₂LiGdCl₆:Ce³⁺ single crystal is a promising candidate for medical imaging and radiation detection.     

First-principles prediction of spin-density-reflection symmetry driven magnetic transition of CsCl-type FeSe

Based on results of density functional theory (DFT) calculations with the local spin density approximation (LSDA) and the generalized gradient approximation (GGA), we propose a new magnetic material, CsCl-type FeSe. The calculations reveal the existence of ferromagnetic (FM) and antiferromagnetic (AFM) states over a wide range of lattice constants. At 3.12 Å in the GGA, the equilibrium state is found to be AFM with a local Fe magnetic moment of . A metastable FM state with Fe and Se local magnetic moments of 2.00 and , respectively, lies 171.7 meV above the AFM state. Its equilibrium lattice constant is ∼2% smaller than that of the AFM state, implying that when the system undergoes a phase transition from the AFM state to the FM one, the transition is accompanied by volume contraction. Such an AFM-FM transition is attributed to spin-density z-reflection symmetry; the symmetry driven AFM-FM transition is not altered by spin-orbit coupling. The relative stability of different magnetic phases is discussed in terms of the local density of states. We find that CsCl-type FeSe is mechanically stable, but the magnetic states are expected to be brittle.     

Global Aspects of Age-Structured Cigarette Smoking Model

Smoking impacts health and as a result creates several problems related to age which means smoking has a strong correlation with age. Keeping this problem in view, we consider the global asymptotic properties of age-structured smoking model. First, we formulate the model and present the existence and uniqueness of solution. Then we discuss the equilibrium points and construct the Lyapunov function to examine global stability of the free smoking and positive smoking equilibrium points. Finally, we fixed the age factor and use the non-standard finite difference (NSFD) scheme for numerical solutions and compare our results obtained with RK4 and ODE45 graphically with the help of MATLAB.