One-step,template-free hydrothermal synthesis of CuO tetrapods

The present investigation reports one-step template-free hydrothermal synthesis of CuO tetrapods (CuO-T) and its characterization. The CuO tetrapods have been prepared in moderate condition without using any surfactant. The prepared sample was characterized by powder X-ray diffraction (PXRD), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, UV–vis–NIR (DRS) spectroscopy and Photoluminescence (PL) spectroscopy. The X-ray diffraction and Fourier transform infrared spectrum analysis confirm clearly the formation of a pure phase high-quality CuO with monoclinic crystal structure. X-ray peak broadening analysis was used to evaluate the average crystallite size (∼30 nm) and lattice strain by the Williamson–Hall (W–H) method. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) result reveals that the particles are tetrapods in shape with an average length ∼50 nm. Additionally the optical properties were investigated by using UV–vis reflectance spectra with considerable blue-shift in the optical band gap (Eg = 1.45 eV) due to quantum confinement effect. Photoluminescence (PL) spectrum showed both UV as well as visible emission peaks indicating their good optical properties.     

Chiral separation of ketoprofen on an achiral NH<Subscript>2</Subscript> column by HPLC using vancomycin as chiral mobile phase additive

A high-performance liquid chromatographic method for chiral separation of ketoprofen racemate was developed. (R)- and (S)-ketoprofen enantiomers were separated on a LiChrosorb NH₂ column (250 mm × 4.6 mm, i.d 5 µm) at 20 °C, using 2-propanol/potassium dihydrogen phosphate buffer (pH 6.0, 0.05 M) (50:50 v/v). Containing vancomycin as the mobile phase, at a flow rate of 0.8 ml min^?1 and detection wavelength of UV, the detector was set at 310 nm. Under these conditions, ketoprofen enantiomers could be separated with a selectivity factor (α) of 2.172 and a resolution (Rs) of 4.78 using extremely low concentrations of the vancomycin chiral additive.     

Synthesis,Mesomorphic and Computational Characterizations of Nematogenic Schiff Base Derivatives in Pure and Mixed State

Homolog series based on three aromatic rings bearing terminal alkoxy chain of various lengths named 4-(4-(alkoxy)phenylimino)methyl)phenyl nicotinate (An) were synthesized. The alkoxy-chain length changed between 6, 8 and 16 carbons. Mesomorphic and optical properties were carried out via differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Elemental analyses, FT-IR and NMR spectroscopy were carried out to elucidate the molecular structures of the prepared derivatives. Mesomorphic results indicated that all the synthesized homologs (An) are monomorphic possessing the nematic (N) phase enantiotropically with wide thermal stability. Computational simulations were measured via density functional theory (DFT) theoretical calculation tool. The estimated thermal and geometrical parameters are in agreement with the experimental data. By discussing the estimated parameters, it was found that the molecular architecture, dipole moment and the polarizability of the investigated compounds are highly affected by the length of the attached terminal flexible chain and the location of the nitrogen atom in the other terminal aromatic ring. Binary phase diagrams of two corresponding homologs with different proportionating terminals were constructed, and their binary phase physical properties were discussed in terms of the temperature range and stability of the N phase.     

Kinetic Instability of Anisotropic Drift Wave Accompanied by Field Aligned Currents in Solar Coronal Loop

Solar coronal loops are frequently accompanied by the field-aligned currents, which drive instabilities if the drift velocity u₀> v_A the Alfvén velocity. For our choice of parameters, the critical threshold value of u₀/v_A is~3.0 for growth and the corresponding current filling factor~10^-3-10^-4. Below this value we are no longer in the kinetic regime. The coronal loops also have short-scale density gradients within each loop. The electron resonance in the presence of density gradient causes the drift mode to grow. We study the effect of these two free energy sources, the electron drift and the density gradient, in the presence of temperature anisotropy T_⊥α > T_||α. These effects simultaneously exist in the coronae. Using gyrokinetic theory, we investigate the influence of these effects, examine how they interplay with each other and study the consequent growth of the magnetosonic wave. We observe that kinetic instability driven by density gradient can be suppressed by field-aligned currents. The temperature anisotropy with chosen signatures causes further stabilizing effect. The results may prove useful to study the heating mechanism of solar coronal loops, acceleration of particles and confinement of particles in the thermonuclear reactors.     

Relaxation theorems in nonlinear elasticity

Relaxation theorems which apply to one, two and three-dimensional nonlinear elasticity are proved. We take into account the fact an infinite amount of energy is required to compress a finite line, surface or volume into zero line, surface or volume. However, we do not prevent orientation reversal.     

Supply chain organization and e-commerce: a model to analyze store-picking, warehouse-picking and drop-shipping

Across many industries, e-commerce generates substantial modifications in supply chain structures. The aim of this article is to assess different forms of existing organizations when a store-based sales network coexists with a web site order network. Three main organizational models can be detected: “store-picking”, “dedicated warehouse-picking” and “drop-shipping”. We use a “newsboy” order policy model to compare the advantages of these different models and to note the impact of some parameters on inventory and flow management policies throughout the supply chain. Several effects are presented, particularly those linked to the size of the Internet market in relation to traditional market size and market demand hazards.      

Inertial Alfven waves in an inhomogeneous bi-Maxwellian plasma

The Vlasov kinetic equation is solved using gyrokinetic theory and the dielectric tensor for non-relativistic, magnetized, bi-Maxwellian plasmas is calculated. A generalized dispersion relation for kinetic Alfven waves is derived taking into account the density inhomogeneity and temperature anisotropy. The modified dispersion relation thus obtained is then used to examine the propagation characteristics of the kinetic Alfven waves in the inertial regime. The importance of density inhomogeneity and temperature anisotropy for Solar corona is highlighted. The growth rate of the inertial Alfven wave proves that density inhomogeneity acts as a source of free energy.     

Structural and optical properties of Li substituted CuO nanoparticles

Copper oxide (CuO) is a favorable material for photovoltaic application where lattice defects/distortions play a significant role for shaping its optical and several other physical properties. In this study, pristine and lithium (Li) substituted CuO nanoparticle (1.0, 3.0, 5.0 and 7.0 mol% of Li) have been prepared via an eco-friendly and cost-effective sol–gel method and a systematic study on the effect of Li ion substitution has been drawn. The Rietveld refinement results confirmed the Li ion substitution obsessed structural alteration from monoclinic to tetragonal symmetry (C2/c?→?I4/mmm). It was observed that the C2/c and I4/mmm synchronized phases continues up to 7%. Such structural alteration leads to fascinating optical properties due to destruction of parent phase. Moreover, lithium cations inhibit the crystal growth, which created various types of vacancy/defect states that essentially need to be investigated using SEM, FTIR and Raman spectroscopy. Moreover, we have demonstrated that the native lattice alterations brought by size misalliance amid the host [Cu²⁺ (0.73 Å)] and the dopant [Li?+?(0.76 Å)] and the presence of oxygen vacancies created via Li substitution in CuO also results in the increment of deep level emission in photoluminescence spectra. The obtained results confirmed that Li ion substitution remarkably enhance optical properties, making such materials promising for device applications.