Enhanced fluorescence sensing using microstructured optical fibers: a comparison of forward and backward collection modes

A general model of excitation and fluorescence recapturing by the forward and backward modes of filled microstructured optical fibers (MOFs) is presented. We also present experimental results for both backward and forward fluorescence recapturing within a MOF as a function of fiber length and demonstrate a good qualitative agreement between the numerical model and experimental results. We demonstrate higher efficiency of fluorescence recapturing into backward modes in comparison with that of forward modes.     

Thermal conductivity of argon,krypton and their mixtures at low temperatures (90-270 k)

Experimental thermal conductivity values of argon, krypton and their mixtures have been measured at 1 atm (101.325 kN/m²) in a specially designed hot-wire cell in the temperature range 90-270 K. These values are compared with the recommended values based on available data for pure systems, and with the predictions of kinetic theory based on L-J (12-6), exp-six and (11-6-8) potentials. Combination rules for predicting the interaction parameters for unlike molecules from the knowledge of parameters for like molecules have been derived for (11-6-8) potential. Two variants of the procedures based on Sutherland-Wassiljewa expressions have also been examined for mixtures.     

Synthesis and Characterization of Some Monoazo Disperse Dyestuffs Based on Naphthalimide Derivatives for Dyeing of Polyester Fabrics

A series of monoazo disperse dyestuffs derived from naphthalimide were prepared. 4‐Amino‐N‐methyl (alternatively N‐ethyl, N‐propyl, N‐butyl) derivatives of naphthalimide were utilised as the diazo components and β‐naphthol, N,N‐diethyl‐m‐toluidine, and p‐aminoacetophenone constituted the coupling components. To this end, acenaphthene was nitrated and then various unit processes such as oxidation, amination, reduction, diazotization, and coupling were carried out. The synthesized monoazo disperse dyestuffs were applied to a locally manufactured polyester fabric and their optical properties were investigated. Characterisation of the various intermediates as well as the dyestuffs were carried out by DSC, FTIR, H‐NMR and UV‐vis analytical techniques.     

Simultaneous X‐ray fluorescence and scanning X‐ray diffraction microscopy at the Australian Synchrotron XFM beamline

Owing to its extreme sensitivity, quantitative mapping of elemental distributions via X‐ray fluorescence microscopy (XFM) has become a key microanalytical technique. The recent realisation of scanning X‐ray diffraction microscopy (SXDM) meanwhile provides an avenue for quantitative super‐resolved ultra‐structural visualization. The similarity of their experimental geometries indicates excellent prospects for simultaneous acquisition. Here, in both step‐ and fly‐scanning modes, robust, simultaneous XFM‐SXDM is demonstrated.     

First principle study of magnetic and electronic properties of single X (X = Al,Si) atom added to small carbon clusters (C<Subscript> <Emphasis Type="Italic">n</Emphasis> </Subscript>X, <Emphasis Type="Italic">n</Emphasis> = 2–10)

In this paper, the magnetic and electronic properties of single aluminum and silicon atom added to small carbon clusters (C_nX; X = Al, Si; n = 2–10) are studied in the framework of generalized-gradient approximation using density functional theory. The calculations were performed for linear, two dimensional and three dimensional clusters based on full-potential local-orbital (FPLO) method. The total energies, HOMO–LUMO energy gap and total magnetic moments of the most stable structures are presented in this work. The calculations show that C_nSi clusters have more stability compared to C_nAl clusters. In addition, our magnetic calculations were shown that the C_nAl isomers are magnetic objects whereas C_nSi clusters are nonmagnetic objects.     

Enhanced photocatalytic activities of TiO<Subscript>2</Subscript>–SiO<Subscript>2</Subscript> nanohybrids immobilized on cement-based materials for dye degradation

Using cement-based material as a matrix for photocatalytic hybrids is an important development for the large-scale application of photocatalytic technologies. In this work, photocatalytic activity of nanosized hybrids of TiO₂/SiO₂ (nano-TiO₂–SiO₂) for degradation of some organic dyes on cementitious materials was highlighted. For this purpose, an optimal inorganic sol–gel precursor was firstly applied to prepare the composites of nano-TiO₂–SiO₂ which was characterized by XRD, SEM and UV–Vis. Then, a thin layer was successfully coated on white Portland cement (WPC) blocks using a dipping process in a nano-TiO₂–SiO₂ solution. The effect of nano-TiO₂–SiO₂-coated WPC blocks on photocatalytic decomposition of three dyes, including Malachite green oxalate (MG), Methylene blue (MB) and Methyl orange (MO) were studied under UV irradiation and monitored by chemical oxygen demand tests. The results showed an increase in photocatalytic effects which depends on the structure and pH of the applied cement.     

Synthesis and Characterization of Some New Indoline-Based 1,2,4-Triazole Derivatives

Russian Journal of Organic Chemistry - Three-component reaction of substituted benzoyl chlorides, ammonium thiocyanate, and isatin in anhydrous acetone gave a series of novel...