Synthesis and structural characterization of dihexamethylenetetraminetetraaquocobalt(II) hexaaquocobalt(II) sulfate hexahydrate

The synthesis and crystal structure of a new three dimensional cobalt(II) complex [Co(C₆H₁₂N₄)₂(H₂O)₄Co(H₂O)₆][SO₄]₂.6H₂O are reported. It crystallizes in the triclinic space group P-1 with a = 13.394(3), b = 16.077(3), c = 9.282(2) Å, = 89.71(2), = 90.42(2), = 114.02(2)°, V = 1825.6(7)ų and Z = 2. The structure is comprised of [Co(C₆H₁₂N₄)₂ (H₂O)₄Co(H₂O)₆][SO₄]₂ units and H₂O molecules. Two molecules of ligand and four molecules of water chelate one type of Co^II in an octahedral fashion through two N and four O atoms: the four O atoms form the equatorial plane and the two N atoms occupy the apical positions. The other type of Co^II cation is chelated by six water molecules.     

Synthesis of β,β‘-Difluorinated and β,β’-F-Dialkylated Acetals

Using the phase transfer catalysis technique, a series of fluorinated acetals has been prepared, in basic medium, by action of dicholromethane on 2-mononfluorinated alcohols or 1-F-alkyl 2-fluoroethanols. The identification of these new acetals has been achived by the study cf their ¹H, 19F NMR and their mass spectra.     

Sustainable potable water production from conventional solar still during the winter season at Algerian dry areas: energy and exergy analysis

Journal of Thermal Analysis and Calorimetry - The Algeria Sahara suffers from the scarcity of drinking water. Solar distillation is one of the simplest and generally inexpensive techniques to solve...     

Parabolic equations with measure data in Orlicz spaces

We prove an existence result for solutions of nonlinear parabolic equations with measure data in Orlicz–Sobolev spaces.     

A General Multiresolution Method for Fitting Functions on the Sphere

In [7], Lyche and Schumaker have described a method for fitting functions of class C ¹ on the sphere which is based on tensor products of quadratic polynomial splines and trigonometric splines of order three associated with uniform knots. In this paper, we present a multiresolution method leading to C ²-functions on the sphere, using tensor products of polynomial and trigonometric splines of odd order with arbitrary simple knot sequences. We determine the decomposition and reconstruction matrices corresponding to the polynomial and trigonometric spline spaces. We describe the general tensor product decomposition and reconstruction algorithms in matrix form which are convenient for the compression of surfaces. We give the different steps of the computer implementation of these algorithms and, finally, we present a test example.     

The first chromate containing both Cr<Subscript>2</Subscript>O<Subscript>7</Subscript> and Cr<Subscript>3</Subscript>O<Subscript>10</Subscript> groups,bis(1,3-bis(4-piperidinium)propane) dichromate trichromate monohydrate: Synthesis and crystal structure

A new organic-inorganic hybrid material (C₁₃H₂₈N₂)₂[Cr₂O₇][Cr₃O₁₀]·H₂O (1) was synthesized by slow solvent evaporation at room temperature, and its crystal structure was determined by single crystal X-ray diffraction. This compound crystallizes in the monoclinic space group P2₁/c. The asymmetric unit contains two crystallographically independent 1,3-bis(4-piperidinium)propane, (H₂bppp)²⁺ cations (A and B), one trichromate Cr₃O ₁₀ ^2? anion, one dichromate Cr₂O ₇ ^2? anion, and one water molecule. All these entities are interconnected into a complicated two-dimensional hydrogen bonded network via N–H?O and O–H?O hydrogen bonds. Furthermore, this structure is stabilized by a large number of C–H?O interactions, thus establishing a three-dimensional network structure. This compound appears to be the first example of chromates containing both Cr₂O₇ and Cr₃O₁₀ groups.     

C 1 Quadratic and C 2 Quartic Macro-Elements on a Modified Morgan-Scott Triangulation

In this paper, we construct a quadratic composite finite element of class C ¹ and quartic composite finite element of class C ² on a new triangulation τ ₁₀ which is obtained by splitting each triangle of a given triangulation τ into ten smaller subtriangles. These new elements can be used for constructing spline spaces with local basis that can be applied for solving some Hermite interpolation problems with optimal approximation order.