Solubility Behavior of Pimozide in Polar and Nonpolar Solvents: Partial Solubility Parameters Approach

The solubility behavior of pimozide in individual solvents ranging from nonpolar to highly polar was studied. For understanding the solute-solvent interactions, the partial solubility parameters concept was utilized. Solutions containing excess drug were shaken in a water bath for 72 hours at 25 °C. After the solutions attained equilibrium, they were filtered and analyzed for drug content. A multiple regression method, using extended Hansen’s partial solubility parameters, was applied to verify the solubilities of pimozide in pure polar and nonpolar solvents and to predict its solubility in untested solvents. The three-parameter approach and the Flory-Huggins size correction term ‘B’ give predictions of solubilities with correlations up to 97%. The four-parameter approach involving proton-donor and proton-acceptor parameters was also used in fitting the solubility data. The correlations are appreciable (94%). Further, the ‘B’ term coupled with four-parameter approach was examined in order to improve the data representation, and resulted in a 1% improvement (98%) in the correlation when compared to the Flory-Huggins size-correction method. The solubility parameter obtained by this method is 10.43 H which is closer to the values obtained by theoretical methods, such as Fedors’ and Hoy’s. The resulting partial solubility parameters are δ _2d =8.85 H, δ _2p =2.17 H, δ _2a =3.15 H, and δ _2b =4.08 H, which give insights into the interaction capability of pimozide and are consistent with its chemical structure. Pimozide is a Lewis base as its δ _2b >δ _2a . The total solubility parameter of pimozide is assigned at 10.43 H. This work demonstrates for the first time the validity of the four-parameter approach coupled with the Flory-Huggins size-correction term and therefore the result is interesting.     

Rhodium Fluoroapatite Catalyzed Conjugate Addition of Arylboronic Acids to α,β‐Unsaturated Carbonyl Compounds

Rhodium fluoroapatite (RhFAP) is an efficient catalyst for conjugate addition of organoboron reagents to α,β‐unsaturated carbonyl compounds. A variety of arylboronic acids and α,β‐unsaturated carbonyl compounds were converted to the corresponding conjugate‐addition products, demonstrating the versatility of the reaction. The reaction is highly selective. RhFAP was recovered quantitatively by simple filtration, and reused for four cycles.     

Catalytic decomposition of CH4 over Ni-Al2O3-SiO2 catalysts: Influence of pretreatment conditions for the production of H2

This article reports the production of COx free hydrogen and carbon nanofibers by the catalytic decomposition of methane over Ni-Al2O3-SiO2 catalysts. The influence of reaction temperature, pretreatment temperature, and effect of reductive pretreatment on the decomposition of methane activity is investigated. The physico-chemical characteristics of fresh and deactivated samples were characterized using BET-SA, XRD, TPR, SEM/TEM, CHNS analyses and correlated with the methane decomposition results obtained. The Ni-Al-Si （4 ： 0.5 ： 1.5） catalyst reduced with hydrazine hydrate produced better H2 yields of ca. 1815 mol H2/mol Ni than the catalyst reduced with 5% H2/N2.     

A variant of Newton's method and its application

This paper details an existence and uniqueness theorem for solving an operator equation of the form F(x)=0, where F is a Gateaux differentiable operator defined on an open convex subset of a Banach space proved. From the main theorem, an earlier theorem of Argyros follows as a consequence. Other corollaries constitute the semilocal versions of the theorems due to Ozban and Weerakoon and Fernando in a general Banach space. Our main theorem leads to the existence of solutions for a class of nonlinear Urysohn-type integral equations in the n-dimensional Euclidean space.     

Graphene: The New Two‐Dimensional Nanomaterial

Every few years, a new material with unique properties emerges and fascinates the scientific community, typical recent examples being high‐temperature superconductors and carbon nanotubes. Graphene is the latest sensation with unusual properties, such as half‐integer quantum Hall effect and ballistic electron transport. This two‐dimensional material which is the parent of all graphitic carbon forms is strictly expected to comprise a single layer, but there is considerable interest in investigating two‐layer and few‐layer graphenes as well. Synthesis and characterization of graphenes pose challenges, but there has been considerable progress in the last year or so. Herein, we present the status of graphene research which includes aspects related to synthesis, characterization, structure, and properties.     

Measurement of the bremsstrahlung spectra generated from thick targets with <Emphasis Type="Italic">Z</Emphasis>=2–78 under the impact of 10 keV electrons

We present new experimental data on thick target bremsstrahlung spectra generated from the interaction of energetic electrons with bulk matter. The ‘photon yields’ in terms of double differential cross-sections (DDCS) are measured for pure elements of thick targets: Ti (Z = 22), Ag (Z = 47), W (Z = 74) and Pt (Z = 78) under the impact of 10 keV electrons. Comparison of DDCS obtained from the experimental data is made with those predicted by Monte-Carlo (MC) calculations using PENELOPE code. A close agreement between the experimental data and the MC calculations is found for all the four targets within the experimental error of 16%. Furthermore, the ratios of DDCS of bremsstrahlung photons emitted from Ag, W and Pt with those from Ti as a function of photon energy are examined with a relatively lower uncertainty of about 10% and they are compared with MC calculations. A satisfactory agreement is found between the experiment and the calculations within some normalizing factors. The variations of DDCS as a function of Z and of photon energy are also studied which show that the DDCS vary closely with Z; however, some deviations are observed for ‘tip’ photons emitted from high Z targets.     

Determination of antimony in lead, zinc concentrates and other smelter products by atomic-absorption spectrophotometry after separation by n-butyl acetate extraction of the chloro-complex

An extractive atomic-absorption spectrophotometric (AAS) procedure is developed for fast and accurate determination of up to 20 mug/g antimony in lead and zinc concentrates and other smelter products. The procedure involves digestion of the sample with potassium bisulphate and sulphuric acid, addition of hydrazine to reduce all antimony to Sb(III), reoxidation to Sb(V), extraction of the chloro-complex of antimony(V) with n-butyl acetate, and AAS analysis of the organic phase for antimony.