A strategy for parallel implementation of finite difference numerical schemes associated to evolution differential equations

Within the framework of parallel numerical treatment, there are many more results on stationary (or time-frozen) PDE's than on their evolution (or time-dependent) counterparts. This is justified as computer simulation of time flow – an intrinsically sequential phenomenum – leads naturally to a sequential algorithm, thus inhibiting any search for concurrent ones. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Counterion Nature and Alkylammonium Halide Adsorption Thermodynamics

Two surfactants were synthesized by reacting hydrogen halides (hydrogen chloride and hydrogen bromide) with 1-dodecylamine. The resultant cationic surfactants, 1-dodecylammonium chloride (DDAC) and 1-dodecylammonium bromide (DDAB), were characterized by NMR spectrometry and FTIR spectroscopy and data related to their adsorption at the fluid liquid/gas interface were obtained employing bubble surface tensiometry, in pure water and in HCl 0.1 M. Data did not fit well to Langmuir isotherm but Frumkin isotherm did adequately describe to process of adsorption. Adsorption isotherms, as well as data related to critical micelle concentration, CMC, indicated that in HCl 0.1 M, the presence of electrolytes and a common ion to DDAC decreased chloride solvation, changing surface packing and adsorption profile for this surfactant.     

Anderson localization in a disordered chain with a finite nonlinear response time

In this work, we investigate the competition of disorder, nonlinearity and non-adiabatic process on the wave packet dynamics in 1D. We follow the time evolution of the second moment of the wave packet distribution to characterize its spreading behavior. In order to describe the dynamical behavior of one-electron wave packets, we solve a discrete nonlinear Schr?dinger equation which effectively takes into account a diagonal disorder and a nonlinear contribution. Going beyond the adiabatic regime, we consider that the nonlinearity relaxes in time according to a Debye-like law. In the adiabatic regime, it has been recently demonstrated that the interplay of disorder and nonlinearity leads to a sub-diffusive spread of the wave packet. Here, we numerically demonstrate that no sub-diffusive spreading of the second moment of the wave packet distribution takes place when the finite response time of the nonlinearity is taken into account.     

Compatibility studies of trioxsalen with excipients by DSC,DTA, and FTIR

Psoralens are widely used for the treatment of psoriasis. Trioxsalen is a drug prescribed low-dose, belonging to the group of substituted psoralen. The aim of this study was to evaluate the compatibility of trioxsalen with pharmaceutical excipients used in the solid forms by analytical techniques. Binary mixtures between the trioxsalen and pharmaceutical excipients (namely, magnesium stearate, α-lactose, microcrystalline cellulose 102, pregelatinized starch, mannitol, sodium lauryl sulfate, sodium starch glycolate, and croscarmellose sodium) were examined. The trioxsalen–sodium lauryl sulfate mixture displayed some physical interaction based on the DTA and DSC results, but the FTIR study ruled out any chemical change.     

Regiospecific synthesis of polyfluorinated heterocycles

A series of 10 heterocycles was obtained from the reaction of 1,1,1-trifluoro-4,4-diethoxy-3-buten-2-one and 1,1,1,2,2-pentafluoro-4,4-diethoxy-3-penten-2-one with different dinucleofiles (hydrazine, methyl hydrazine, hydroxylamine and sodium cyanide). The pyrazoles, 4,5-dihydroisoxazoles and pyrrolidinones polyfluoroalkyl substituted were obtained in moderate to good yields under mild conditions.     

Use of ionizing radiation for the study of the stabilization of tetrafluoroethylene

TFE is highly unstable. It can easily go through an explosive disproportionation reaction under polymerization. The present work proposes the use of ionizing radiation for the study of monomer stability by inducing the polymerization and disproportionation reactions. Radiation was used to promote the initiation of TFE polymerization with and without inhibitors. Inhibitors and TFE were irradiated by γ-rays from ⁶⁰Co. Small explosions with polymerization were observed yielding oligomer and polymer plus byproducts. It was shown that the initiation was completely inhibited by the addition of 0.1% of -pinene, dipentene, terpinolene or its mixture 1:1:1. In conclusion, radiation is a safe, reliable and easily controllable method to study TFE stabilization.     

Some specific unboundedness property in smoothness Morrey spaces. The non-existence of growth envelopes in the subcritical case

We study smoothness spaces of Morrey type on Rn and characterise in detail those situations when such spaces of type A_(p,q)~(s,r)(R~n) or A_(u,p,q)~s(R~n) are not embedded into L_(∞)(R~n).We can show that in the so-called sub-critical,proper Morrey case their growth envelope function is always infinite which is a much stronger assertion.The same applies for the Morrey spaces M_(u,p)(R~m) with p u.This is the first result in this direction and essentially contributes to a better understanding of the structure of the above spaces.     

Assessment of iodine content in Brazilian duplicate portion diets and in table salt

Excess dietary intake may increase the risk for the hyperthyroidism in the elderly. This study investigated iodine dietary intake by epithermal neutron activation analysis (ENAA) analyzing duplicate portion diet and fortified table salt samples. Duplicate diet samples were obtained from a group of twenty-five steel mill workers from the city of São Paulo, over a 3-day period. The samples were freeze dried, mixed and homogenized. Fortified table salt brands were collected from the market and were analyzed with no pre-treatment. Assays for the iodine concentration in the table salt samples revealed values between 24 to 65 mg/kg. The average iodine daily intake for the worker’s diets was 813 μg/day, ranging from 402 to 1363 μg/day. In some cases daily intakes were around 10 times higher than the recommended dietary allowance (RDA) value (150 μg/day).     

Continuity envelopes and sharp embeddings in spaces of generalized smoothness

We study continuity envelopes in spaces of generalized smoothness and . The results are applied in proving sharp embedding assertions in some limiting situations.