An alumino-silicate zeolite, Linde Type-A (LTA) has been prepared from aluminium powder and sodium metasilicate by hydrothermal process. The zeolite was characterized by FTIR and X-ray diffraction (XRD) analysis and by measuring the surface acidity using KOH as adsorbate. The surface acidity of LTA zeolite varied greatly with varying synthesized conditions such as crystallization temperature, c...

The effect of alcoholic extract of Nigella sativa was investigated in rats to evaluate the anti-ulcer activity by using two models, i.e. pyloric ligation and aspirininduced gastric ulcer. The parameters taken to assess anti-ulcer activity were volume of gastric secretion, free acidity, total acidity and ulcer index. The results indicate that the alcoholic extract significantly (P < 0.001) decre...

A three-way resolution method based on PARAFAC model was applied for the UV-Vis spectra to study the simultaneous degradation of anthocyanins extracted from fresh calyces of flowers of the Hibiscus sabdariffa. This methodology was used to resolve a chemical system, for which there was no a priori information about the composition or the pure spectra, a so-called black system. In the pH range fr...

Efficient synthesis of furfural from xylose over the HCl catalyst in a water-methyl isobutyl ketone biphasic system was achieved slug flow microreactors, using NaCl as promotor which facilitates dehydration and suppresses condensation. An optimized yield 93% obtained 1 M 0.2 with 10 wt% at 180°C within 4 min. A comprehensive kinetic model developed monophasic experiments water by incorporating ...

Remotely keyed encryption (RKE) schemes provide fast symmetric encryption and decryption using a small-bandwidth security module and a powerful host. Such schemes keep the key inside the security module to prevent key compromise. Shin, Shin, and Rhee proposed a length-preserving as well as a length-increasing RKE scheme that both use only a single round of interaction between host and security ...

FVMany different dosage schedules of antisecretory drugs for the treatment of duodenal ulcer are recommended. The relationship between degree of acid suppression and therapeutic efficacy has not been precisely defined for these drugs. We have examined the association between suppression of intragastric acidity and duodenal ulcer healing rates for a number of therapeutic regimens. For the H2 rec...

A comparative research has been developed for acidity and stability constants of M(Glu), M(Asp) and M(Ttr) complexes, which have been determined by potentiometric pH titration. Depending on metal ion-binding properties, vital differences in building complex were observed. The present study indicates that in M(Ttr) complexes, metal ions are arranged to the carboxyl groups, but in M(Glu) and M(As...

Introduced here is a quick, simple, robust method to measure acidity in ionic liquid (IL) systems by the use of the NMR-probe mesityl oxide. Acidity corresponding to a Hammett acidity of -1 to -9 can be measured reliably using this technique, a range that vastly exceeds that of any single UV-vis probe.

The conformational populations of cis-1,3-cyclopentanedicarboxylic acid (1) and its mono- and dianion were established in DMSO solution by comparing the vicinal proton–proton coupling constants (3J(HH)) obtained in solution to their theoretical counterparts. Geometries used for 3J(HH) theoretical estimation (using Karplus-type equations) were obtained from optimized structures at the B3LYP/6-31...