Materials Literature
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Summary In some soils, aggregate coatings and walls of biopores differ in the content of clay and organic carbon from that of the aggregate interiors or the soil matrix. The composition of the organic matter on aggregates and on the surfaces of biopores is largely unknown. We have compared the composition of organic m…
On the basis of Friedel approach the theoretical description of the effects of resonance scattering of conduction electrons by donor impurities in semiconductors with allowance for the stabilization of electron concentration in coinciding the Fermi energy with the resonance level energy has been developed. It has been…
Dynamics of a one-dimensional growing front with an unstable straight profile are analyzed. We argue that a coarsening process occurs if and only if the period λof the steady state solution is an increasing function of its amplitude A. This statement is rigorously proved for two important classes of conserved and nonc…
This study reports the effect of a change in crystal form on the quality of interactive mixtures prepared with homogenous sugar beads and the three polymorphs of chloramphenicol palmitate (CAP). Six mixtures containing micronized CAP polymorph powder (0.5%) and sugar beads (99.5%) were mixed in a Turbula mixer at 27 r…
Complexation between poly(methyl vinyl ether-maleic anhydride) copolymer (Gantrez AN 169) and polyvinylpyrrolidone (PVP K-90D) in aqueous solutions were investigated using a viscometric method and Raman spectroscopy. The composite films with different weight ratios of PVP to Gantrez were prepared in the presence of N-…
The aim of this work is to evaluate the feasibility of hydrophilic silica aerogels as drug carriers and to investigate the influence of the aerogels properties on the release rate of poorly water-soluble drugs. Hydrophilic silica aerogels of different densities were loaded with two model drugs, ketoprofen and griseofu…
The title compound, octa-tert-butoxybis[micro(3)-2,2'-(N-methylimino)diethanolato]di-micro-oxo-tetratitanium(IV), [Ti(2)O[(OCH(2)CH(2))(2)(NCH(3))][(CH(3))(3)CO](4)](2) or [Ti(4)(C(5)H(11)NO(2))(2)(C(4)H(9)O)(8)O(2)], lies about an inversion centre, and displays the less usual zigzag configuration. One O atom of the N…
Polyurethane (PU) foam was hydrolytically depolymerized in 0.5 L capacity high-pressure autoclave equipped with magnetic stirrer at 100, 130, 150, 170, 200, and 220°C and at 15, 51, 80, 153, 230, and 405 psi pressures. The percentage conversion of PU foam to polyamines and polyols on the basis of amine value and hydro…
Chloroprene rubber was blended with whole tire reclaimed rubber (WTR) in presence of different levels of a coupling agent Si69 [bis-(3-(triethoxysilyl)propyl)tetrasulfide] and the cure characteristics and mechanical properties were studied. The rate and state of cure were also affected by the coupling agent. While the…
The infrared spectra of xanthated cellulose and its blends with polyvinyl alcohol (PVA) in different ratios were investigated. The dielectric constant, loss tangent, and AC-conductivity of the prepared blends were measured at different temperatures (293–373K) in the frequency range (100 Hz–5 MHz). The decrease in the…
The haptotropic rearrangement of diiron carbonyl species on the conjugate π-ligand in (μ 2,η 3:η 5 -acenaphthylene)Fe 2 (CO) 5 ( 1 ) and its analogue (μ 2,η 3:η 5 -aceanthrylene)Fe 2 (CO) 5 ( 2 ) is investigated in both solution and solid states. The diiron complexes 1 and 2 have two isomers, and each isomer is isolat…
Thermodynamic perturbation theory is used to calculate the free energies and resulting phase diagrams of binary systems of spherical colloidal particles and interacting polymer coils in a good solvent within an effective one-component representation of such mixtures, whereby the colloidal particles interact via a poly…
Glasses from the two systems, x Fe 2 O 3 · (100-x)[ P 2 O 5 · CaO ] and x( Fe 2 O 3 · V 2 O 5 ) · (100-x)[ P 2 O 5 · CaO ] with 0 ≤ x ≤ 50 mol% were prepared under the same conditions and characterized by IR spectroscopy. The way in which Fe 2 O 3 and ( Fe 2 O 3 · V 2 O 5 ) influences the local structure of these glas…
This study evaluates the effect of uv/ozone treatments as a source of surface modifications on the properties of some polymeric fabrics. Thus, pure wool, pure polyester, and blended (wool/polyester 65/35%) fabrics are treated with uv/ozone for different time periods (1, 3, 5, 10, 15, and 20 min). The treated samples a…
End-capped poly(L-lactide) (PLLA) samples with dodecyl or 2-(2-(2-methoxyethoxy)ethoxy)ethyl (MEEE) ester were synthesized by ring-opening polymerization of L-lactide in the presence of zinc dodecanoxide or zinc 2-(2-(2-methoxyethoxy)ethoxy)ethoxide as a catalyst, respectively. On the basis of NMR analysis, it was con…
Ceramic strontium ferrites belonging to the M-type hexagonal ferrites have been prepared by the ceramic technique. They were then characterized using x-ray diffraction method and incorporated into natural rubber (NR) matrix according to a specific recipe to produce rubber ferrite composites (RFC). RFC are magnetic pol…
PDMS−M x O y (where M = Ge(IV), Ti(IV), Zr(IV), Nb(V), and Ta(V)) hybrid materials have been studied from the solution to the solid state through 17 O NMR spectroscopy. Si−O−Si, Si−O−M, and M−O−M oxo bridges could be identified, giving a better picture of the structure of these hybrid materials based on amorphous meta…
In this paper we report the controlled expansion of pores within mesoporous silicas using supercritical carbon dioxide (sc-CO 2 ). Our method uses the tunable density of sc-CO 2 to induce the controlled swelling of the triblock copolymer surfactant templating agents, P123 (PEO 20 PPO 69 PEO 20 ) and P85 (PEO 26 PPO 39…
In this study, pioneering results on specific chemical modifications of wheat gluten gliadins and the corresponding impact on mechanical and water barrier properties of derived films are presented. Films were prepared from gliadins chemically treated with formaldehyde and subsequently mixed with different concentratio…
A wattle-type heteropolynuclear complex [(CuL)Mn(N(3))(2)](n) (1) (H(2)L = 2,3-dioxo-5,6:15,16-dibenzo-1,4,8,13-tetraazacyclo-pentadeca-7,13-diene), which represents the first system with macrocyclic oxamido and alternate azido bridges, forming a one-dimensional chain structure, has been synthesized and characterized…