Testing the applicability of artificial intelligence techniques to the subject of erythemal ultraviolet solar radiation part one: the applicability of a fuzzy rule based approach

This work presents the applicability of applying a fuzzy logic approach to the calculation of noontime erythemal UV irradiance for the plain areas of Egypt. When different combinations of data sets were examined from the test performance point of view, it was found that 91% of the whole series was estimated within a deviation of less than +/-10 mW/m(2), and 9% of these deviations lay within the range of +/-15 mW/m(2) to +/-25 mW/m(2).     

Application of Fe3O4@SiO2@sulfamic acid magnetic nanoparticles as recyclable heterogeneous catalyst for the synthesis of imine and pyrazole derivatives in aqueous medium

Research on Chemical Intermediates - Sulfamic acid supported on Fe3O4@SiO2 superpara magnetic nanoparticles was successfully applied as a recyclable solid acid catalyst with a large density of...     

Benzimidazole- and benzothiazole-quinones: excellent substrates for NAD(P)H:quinone oxidoreductase 1

A series of benzimidazole- and benzothiazole-quinones has been synthesized. The ability of these heterocyclic quinones to act as substrates for recombinant human NAD(P)H:quinone oxidoreductase (NQO1), a two-electron reductase upregulated in tumour cells, was determined. Overall, the quinones were excellent substrates for NQO1.     

Synthese und Koordination von 2-Acetylimino-1,3-dimethylimidazolin. Die Kristallstruktur von [Cu4I4(C7H11N3O)2] [1]

Synthesis and Coordination of 2-Acetylimino-1,3-dimethylimidazoline. The Crystal Structure of [Cu₄I₄(C₇H₁₁N₃O)₂] 2-Acetylimino–1,3-dimethylimidazoline ( 2 , ImNAc) obtained from 1,3-dimethyl-2-iminoimidazoline ( 1 ) and acetyl chloride forms with CuI the stepped cubane type complex [Cu₄I₄(ImNAc)₂] ( 3 ); the X-ray structure of 3 is reported.     

An optimization method based on the generalized polynomials for nonlinear variable-order time fractional diffusion-wave equation

In this paper, an optimization method based on a new class of basis functions, namely generalized polynomials (GPs), is proposed for nonlinear variable-order time fractional diffusion-wave equation. Variable-order time fractional derivative is expressed in the Caputo sense. In the proposed method, solution of the problem under consideration is expanded in terms of GPs with unknown free coefficients and control parameters. In this way, some new operational matrices of the ordinary and fractional derivatives are derived for these basis functions. The residual function and its 2-norm are employed for converting the problem under study to an optimization one and then choosing the unknown free coefficients and control parameters optimally. As a useful result, the necessary conditions of optimality are derived as a system of nonlinear algebraic equations with unknown free coefficients and control parameters. The validity and effectiveness of the method are demonstrated by solving some numerical examples. The results demonstrate that the proposed method is a powerful algorithm with good accuracy for solving such kind of problems.     

Room-temperature electroluminescence in the mid-infrared (2-3 microm) from bulk chromium-doped ZnSe

Electroluminescence associated with impact excitation or ionization of deep Cr(2+) impurity centers in bulk ZnSe is reported. A broad signal of mid-infrared luminescence between 2 and 3 microm is observed once the biased bulk ZnSe device runs into a nonlinear conduction regime. Optical powers in the nanowatt range have been measured at room temperature. The different mechanisms involved in this intracenter infrared light emission are discussed.     

Evaluation of essential oils for maintaining postharvest quality of Thompson seedless table grape

The effects of postharvest spraying of essential oils from sweet basil (Ocimum basilicum), fennel (Foeniculum vulgare), summer savory (Satureja hortensis) and thyme (Thymus vulgaris) on fungal decay and quality parameters of the 'Thompson seedless' table grape stored at 0?±?1°C for 60 days were evaluated. Results showed that the essential oils, especially of thyme and fennel, have a good inhibitory effect on the development of fungal decay in Thompson table grapes. In addition, essential oils reduced weight loss, berry and rachis browning and had no considerable adverse effect on the flavour of the fruits. GC-MS analysis showed that the main compounds identified in sweet basil, fennel, summer savory and thyme oils are linalool (65.25%), trans-anethole (64.72%), carvacrol (54.14%) and β-ocimene (12.62%), respectively. Therefore, these essential oils have good potential for use as an alternative to synthetic fungicides for the preservation and storage of table grapes.     

High precision refractometry based on Fresnel diffraction from phase plates

When a transparent plane-parallel plate is illuminated at a boundary region by a monochromatic parallel beam of light, Fresnel diffraction occurs because of the abrupt change in phase imposed by the finite change in refractive index at the plate boundary. The visibility of the diffraction fringes varies periodically with changes in incident angle. The visibility period depends on the plate thickness and the refractive indices of the plate and the surrounding medium. Plotting the phase change versus incident angle or counting the visibility repetition in an incident-angle interval provides, for a given plate thickness, the refractive index of the plate very accurately. It is shown here that the refractive index of a plate can be determined without knowing the plate thickness. Therefore, the technique can be utilized for measuring plate thickness with high precision. In addition, by installing a plate with known refractive index in a rectangular cell filled with a liquid and following the described procedures, the refractive index of the liquid is obtained. The technique is applied to measure the refractive indices of a glass slide, distilled water, and ethanol. The potential and merits of the technique are also discussed.     

Ultrafast shock compression and shock-induced decomposition of 1,3,5-triamino-2,4,6-trinitrobenzene subjected to a subnanosecond-duration shock: an analysis of decomposition products

Shock compression studies of pressed and confined ultrafine 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) powder were conducted using ultrashort ~300 ps, ~50 GPa shock waves. The recovered decomposition products were characterized using X-ray photoelectron spectroscopy, infrared spectroscopy, and Raman spectroscopy. A substantial amount of shock-related chemistry was observed. Approximately 75% of the nitrogen atoms were liberated as gas-phase species, along with ~33% of the oxygen atoms, as a result of the applied shock. Furthermore, we observe C 1s binding energies suggesting the formation of sp(3) hybridized amorphous carbon. For comparison, a carbon nitride material was also prepared and characterized by thermally pyrolizing TATB. The shock-compressed TATB and the thermally pyrolized TATB are qualitatively different, suggesting that, carbon nitrides, a possible indicator of nitrogen-rich heterocycles precursors, are not a major product class for strongly overdriven shock conditions. These experimental conditions were, however, not detonation conditions, and the possible formation of nitrogen-rich heterocycles in actual detonations still exists.     

Oxidative Coupling of Dimethylformamide with β-Dicarbonyl Compounds Using γ-Fe2O3@CuO Nanoparticles

Russian Journal of Organic Chemistry - Maghemite–copper oxide nanocomposite catalyzed oxidative coupling of formamides with β-dicarbonyl compounds in the presence of tert-butyl...