Alachlor has been widely used in agriculture all over the world. It is suggested that it may be a carcinogen and an environmental
estrogen. The aim of this work was to verify the degradation the alachlor by gamma radiation. Gamma radiation from 60Co was used to degrade the alachlor herbicide in water and methanol solution. The alachlor in water and alcohol solution in
the concentration of 100 mgL−1 was irradiated with doses of 0.25–50 kGy, at dose rate 5–6 and 2.7 kGyh−1. High performance liquid chromatography was used as an analytical technique to determine the degradation rate of herbicide
Authors:R. Cunha e Silva, E. Almeida, E. Valencia, and V. Filho
Total reflection X-ray fluorescence (TXRF) was used to determine simultaneously the concentration of Cu, Fe and Zn in seven
sugar-cane spirit samples (“aguardente”), a processed alcoholic beverage made from the fermentation and distillation of sugar-cane
juice. The limits of detection ranged from 35 to 8 ng.ml-1 for V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As and Se. Excluding Fe, Cu and Zn, the concentrations were below their limits. Two samples
showed Cu concentrations higher than the value allowed by Brazilian legislation (5 µg.ml-1), and concerning Fe and Zn, no sample were above the limits permitted by WHO for drinking water (2 and 3 µg.ml-1, respectively).
Ionizing radiation was used for the purpose of reducing bacterial contamination in mechanically deboned chicken meat (MDCM).
Irradiated and non-irradiated MDCM stored at -18±1 °C, and samples were taken at zero time and at 30-day intervals up to 90
days for 2-thiobarbituric acid reactive substances, sensory and microbiological analyses. The results obtained for the microbiological,
sensory and lipid oxidation evaluations, showed that the MDCM samples irradiated with doses of 3.0 and 4.0 kGy were all considered
acceptable during 90 days of frozen storage.
A procedure for the isolation of137Cs from acidic fission products solutions, based on the use of silica gel and zirconium phosphate ion exchangers, is presented. The137Cs recovered by the ion-exchange process is converted to powder by coprecipitation of cesium with ammonium molybdophosphate.137Cs pellets have been prepared by compression of137Cs ammonium molybdophosphate powder using a hydraulic press. An important aspect of this procedure is that it does not require neutralization of the Purex waste.
New measures of noncompactness for bounded sets and linear operators, in the setting of abstract measures and generalized limits, are constructed. A quantitative version of a classical criterion for compactness of bounded sets in Banach spaces by R. S. Phillips is provided. Properties of those measures are established and it is shown that they are equivalent to the classical measures of noncompactness. Applications to summable families of Banach spaces, interpolations of operators and some consequences are also given.
Composites of poly(vinyl pyrrolidone)/hydroxyapatite (PVP/HA), at variable proportions (100/0; 80/20; 50/50; 20/80 wt%) were
prepared and characterized by Fourier transformer-infrared spectroscopy (FT-IR), wide angle X-ray diffraction (WAXD), differential
scanning calorimetry (DSC), and thermogravimetry/differential thermogravimetry (TG/DTG). PVP carbonyl stretching was slightly
shifted to lower frequency in composites indicating the formation of hydrogen bonding with HA hydroxyl groups. At the first
cycle of heating, the calorimetric curves revealed a broad peak the intensity of which was reduced insofar as the amount of
PVP decreased in the composites. This peak was attributed to the PVP enthalpy relaxation. According to the TG/DTG curves,
PVP degraded into two steps sharply perceivable in the composites. The first decay was ascribed to the release of the pyrrolidone
pendant groups and the following one concerned the burning of the hydrocarbon chains. The HA molecules seem to exert a catalytic
action on the PVP degradation.
Study of excipients incompatibility with drugs in an early phase of pharmaceutical development is still a persistent difficulty
within the pharmaceutical industry. We examine here the compatibility between an experimental drug (nebicapone) and common
excipients using differential scanning calorimetry (DSC), high sensitivity DSC (HSDSC) and a conventional heat stress test.
The results obtained indicate that nebicapone may be compatible with lactose monohydrate and sodium croscarmellose but is
incompatible with magnesium stearate. This study concludes that HSDSC, in stepwise isothermal mode, may be used as a potential
tool for detecting excipient incompatibilities.
Authors:M. Cost E. Silva, L. Silva, P. Guedes-De-Pinho, and R. Costa
Aroma is one of the first sensorial characteristics affecting the perception of quality of salted dried codfish. In this work, the volatile profile of different commercially available salted dried codfishes was characterized by HS-SPME/GC-IT-MS. Samples of three species (Gadus morhua, Gadus macrocephalus and Theragra calchogramma), subjected to two curing processes (Traditional and Yellow curing) for different durations caught in distinct pools, were studied.Thirty compounds were fully characterized and 25 were tentatively identified and comprising several chemical classes (amines, hydrocarbons, esters, chlorinated compounds, aldehydes, aromatic, alcohols, acids, sulphur compounds, ethers, ketones and terpenes), with 26 of them being reported for the first time in codfish. Principal component analysis (PCA) showed major differences for the yellow cured sample and for T. chalcogramma species. Yellow cured codfish presented a higher content of compounds of almost all classes. T. chalcogramma exhibited a high content of terpenes and a low amount of aldehydes.
Authors:L. Sanders, C. Sanders, W. Luiz-Silva, W. Machado, E. Silva-Filho, and S. Patchineelam
A sediment core from an estuarine area receiving drainage from the highly industrialized Cubatão River basin (SE Brazil) showed
226Ra and 210Pb activities up to 80 and 213 Bq kg−1, respectively, which are greater than activities considered as regional background levels. Radionuclides and the elevated
phosphorus concentrations (up to 0.3% sediment dry weight) found along the sediment core were significantly correlated with
each other, indicating source similarity. These results indicate that 226Ra and 210Pb activities are affected by fertilizer industry-derived inputs in addition to natural sources. This interpretation was supported
by 210Pb/226Ra ratios (found to be between 2.6 and 3.9) that indicate disequilibrium between 226Ra and its decay product 210Pb, as expected for phosphogypsum-affected sediments.
Authors:E. da Silva Filho, Oberto da Silva, Maria da Fonseca, Luiza Arakaki, and C. Airoldi
A series of compounds with
composition of Ca1–xCuxHPO4,
where x varied from 0.05 to 0.5 were synthesized
by precipitation method. The compounds were characterized by elemental analysis,
X-ray diffraction, infrared spectroscopy, scanning electron microscopy, and
thermogravimetry. The chemical stabilities of solids were investigated at
several pH. Elemental analysis of copper, calcium and phosphorus are in agreement
with the proposed composition. The formation of lamellar phosphates was evidenced.
The stability of the set of compounds was better for samples with high copper