Pyrohydrolytic separation technique for fluoride and chloride from radioactive liquid wastes

A rapid method for simultaneous determination of fluorine and chlorine in radioactive liquid wastes with ion chromatography after pyrohydrolysis separation was proposed for routine analysis. The elements were separated from radioactive liquid wastes by pyrohydrolysis and were subsequently determined with ion chromatograpy. Total time taken to determine these elements is about 45 min including 30 min for the pyrohydrolysis and 15 min for ion chromatography. The results of recovery tests ranged 95% or above. The limits of detection for F and Cl are 0.5 and 0.8 mg kg⁻¹, respectively.     

Lysinated Multiwalled Carbon Nanotubes with Carbohydrate Ligands as an Effective Nanocarrier for Targeted Doxorubicin Delivery to Breast Cancer Cells

Multiwalled carbon nanotubes (MWCNTs) are elongated, hollow cylindrical nanotubes made of sp2 carbon. MWCNTs have attracted significant attention in the area of drug delivery due to their high drug-loading capacity and large surface area. Furthermore, they can be linked to bioactive ligands molecules via covalent and noncovalent bonds that allow for the targeted delivery of anticancer drugs such as doxorubicin. The majority of methodologies reported for the functionalization of MWCNTs for drug delivery are quite complex and use expensive linkers and ligands. In the present study, we report a simple, cost-effective approach for functionalizing MWCNTs with the carbohydrate ligands, galactose (GA), mannose (MA) and lactose (LA), using lysine as a linker. The doxorubicin (Dox)-loaded functionalized MWCNTs were characterized using FT-IR, NMR, Raman, XRD and FE-SEM. The drug–loaded MWCNTs were evaluated for drug loading, drug release and cell toxicity in vitro, in breast cancer cells. The results indicated that the carbohydrate-modified lysinated MWCNTs had greater Dox loading capacity, compared to carboxylated MWCNTs (COOHMWCNTs) and lysinated MWCNTs (LyMWCNTs). In vitro drug release experiments indicated that the carbohydrate functionalized LyMWCNTs had higher Dox release at pH 5.0, compared to the physiological pH of 7.4, over 120 h, indicating that they are suitable candidates for targeting the tumor microenvironment as a result of their sustained release profile of Dox. Doxorubicin-loaded galactosylated MWCNTs (Dox-GAMWCNTs) and doxorubicin loaded mannosylated MWCNTs (Dox-MAMWCNTs) had greater anticancer efficacy and cellular uptake, compared to doxorubicin–loaded lactosylated MWCNTs (Dox-LAMWCNTs) and pure Dox, in MDA-MB231 and MCF7 breast cancer cells. However, neither the ligand conjugated multiwall blank carbon nanotubes (GAMWCNTs, MAMWCNTs and LAMWCNTs) nor the lysinated multiwalled blank carbon nanotubes produced significant toxicity in the normal cells. Our results suggest that sugar-tethered multiwalled carbon nanotubes, especially the galactosylated (Dox-GAMWCNTs) and mannosylated (Dox-MAMWCNTs) formulations, may be used to improve the targeted delivery of anticancer drugs to breast cancer cells.     

Photo-transformations of 6-chloro-3-propargyloxy-2-aryl-4-oxo-4H-1-benzopyran: 1,4-hydrogen abstraction in propargylethers

1,4-Biradicals generated in the Norrish type-II reactions of 3-propargyloxy-2-arylchromones lead to cyclic products involving the 2-aryl group. The formation and distribution of products varied with the nature of 2-aryl group.     

An oxidimetric method for the determination of thiophanatemethyl in commercial formulations

A simple, accurate and reliable titrimetric method is described for the determination of thiophanate-methyl, an important commercial fungicide. The method is based on its direct titration at room temperature with ammonium hexanitratocerate(IV) in sulphuric acid medium in the presence of potassium iodate as catalyst. The method permits detection of the end-point visually, potentiometrically or spectrophotometrically. The proposed method is recommended for routine determination of the fungicide in its commercial formulations.     

Error analysis for convex separable programs: Bounds on optimal and dual optimal solutions

Computable lower and upper bounds on the optimal and dual optimal solutions of a nonlinear, convex separable program are obtained from its piecewise linear approximation. They provide traditional error and sensitivity measures and are shown to be attainable for some problems. In addition, the bounds on the solution can be used to develop an efficient solution approach for such programs, and the dual bounds enable us to determine a subdivision interval which insures the objective function accuracy of a prespecified level. A generalization of the bounds to certain separable, but nonconvex, programs is given and some numerical examples are included.     

Determination of microgram quantities of gadolinium by cathode-ray polarography

A cathode-ray polarographic method has been developed for the determination of microgram quantities of gadolinium with the use of an azo-dye, Solochrome Violet RS. Disadvantages in the use of 0sd1M potassium chloride, commonly recommended as electrolyte for the polarographic determination of rare earths, have been demonstrated. The influence of pH, temperature, ligand concentration and purity, and the stability of the complex, have been investigated for the optimum performance of the method. The linear range is 0.5-12 mug/ml of gadolinium. Interferences by some lanthanides and other cations have been examined.     

Dielectric relaxation and ac conduction in multiferroic Bi0.8Gd0.1Pb0.1Fe0.9Ti0.1O3 ceramics: impedance spectroscopy analysis

ABSTRACT

The solid solutions of Bi_0.8Gd_0.1Pb_0.1Fe_0.9Ti_0.1O₃ have been prepared by the solid-state reaction method. The preliminary structural studies were carried out by X-ray diffraction technique showing the formation of polycrystalline sample with ABO₃ type of perovskite structure with hexagonal symmetry for the Bi_0.8Gd_0.1Pb_0.1Fe_0.9Ti_0.1O₃ ceramic system at room temperature. Dielectric properties and impedance study of this ceramic have been characterized in the temperature range room temperature to 375 °C and frequency range 100 Hz–1 MHz. The maximum ferroelectric transition temperature (T_c) of this system was in the range 200 °C–260 °C with the dielectric constant of peak to be ～30,170 at 1 kHz. The complex impedance plot exhibited one impedance semicircle observed at low temperature, whereas two semicircles above 80 °C and the centres of the semicircles lie below the real axis, which indicates that the material is non-Debye type. Single semicircle is explained by the grain effect of the bulk and double semicircle is due to the bulk and grain boundary effect. The bulk resistance and grain boundary resistance of the materials decrease with the increasing temperature, showing negative temperature and a typical semiconducting property, i.e. negative temperature coefficient of resistance behaviour.     

Recent observational constraints on EoS parameters of a class of emergent Universe

New Sr-based Y-type nanocrystalline hexagonal ferrites with a nominal chemical composition of Sr ₂Mg ₂Fe ₁₂ O ₂₂ (Sr ₂Y) were prepared by autocombustion from mixtures of Sr(NO ₃) ₂, Mg(NO ₃) ₂?6H ₂O and Fe(NO ₃) ₃?9H ₂O. The newly prepared Sr ₂Y nanocrystalline particles were characterized by powder X-ray diffraction (XRD). A well crystalline phase of Sr ₂Y with hexagonal crystal structure was observed. Fourier transform infrared spectroscopy (FTIR) studies revealed the information about the positions of the ions and their bonds within the lattice structure of the Sr ₂Y. The chemical elements and their oxidation states in the Sr ₂Y hexaferrites were determined using X-ray photoelectron spectroscopy (XPS). The XRD, FTIR and XPS studies confirmed the formation of Sr ₂Mg ₂Fe ₁₂ O ₂₂ hexaferrites. The morphology and porosity of the prepared Sr ₂Y nanocrystalline Sr ₂Y hexaferrite particles were studied by field emission scanning electron microscopy. The magnetic properties of Sr ₂Y hexaferrites showed dependence on the methods of preparation conditions and calcination treatments. The values of coercivity, saturation magnetization and retentivity were in the range of 21.33–19.66 kA m ^?1, 42.44– 38.72 emu g ^?1 and 10.05–13.19 emu g ^?1 respectively.