Two milling time regimes in the evolution of magnetic anisotropy of mechanically alloyed soft magnetic powders

The milling time evolution of magnetic anisotropy of ball milled powders can be described considering two regimes. First, for short milling times, the main factor affecting the magnetic behavior of the alloy is the accumulation of internal stresses. Second, for long milling times, magnetic anisotropy can be explained using three contributions: long-range magnetoelastic, averaged short-range magnetoelastic and averaged magnetocrystalline anisotropies.     

Analysing metals in bottle‐grade poly(ethylene terephthalate) by X‐ray fluorescence spectrometry

After a rigorous cleaning process, recycled food‐grade poly(ethylene terephthalate) (PET), can be mixed with virgin PET resin in different concentrations and used for packaging of soft drinks. Therefore, it is important to have an experimental method to distinguish the presence of recycled polymer in a batch and to check its “true quality.” One of the issues to be verified is the presence of inorganic contaminants due to the recycling process. X‐ray fluorescence technique is one alternative for this kind of analysis. The results obtained in this work show that bottle‐grade PET samples (PET‐btg) are made either via direct esterification or by a transesterification process. Samples that were subjected to thermo‐mechanical processings (superclean® processing, PET‐btg blends processed in our laboratory and soft drink PET packaging) present Fe Kα emission lines with higher intensities than those presented by virgin bottle‐grade PET. After applying principal component analysis, it can be concluded that Fe is an intrinsic contaminant after the recycling process, furnishing a way to indicate class separations of PET‐btg. A calibration and validation partial least squares model was constructed to predict the weight percent of post‐consumption bottle‐grade PET in commercial PET samples. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Effect of different mixers on physicochemical properties and water status of extruded and laminated fresh pasta

Physicochemical properties and water status of fresh pasta (both extruded and laminated) produced with recently designed mixers (Premix^® and Bakmix^®) that induce a uniform hydration of the solids and allow the formation of a dough in 1–2 s were evaluated.     

Lonidamine solid dispersions: in vitro and in vivo evaluation

Solid dispersions of lonidamine in PEG 4000 and PVP K 29/32 were prepared by the spray-drying method. Then, the binary systems were studied and characterized using differential scanning calorimetry, hot stage microscopy, and x-ray diffractometry. In vitro dissolution studies of the solid dispersed powders were performed to verify if any lonidamine dissolution rate or water solubility improvement occurred. In vivo tests were carried out on the solid dispersions and on the cyclodextrin inclusion complexes to verify if this lonidamine water solubility increase was really able to improve the in vivo drug plasma levels. Drug water solubility was increased by the solid dispersion formation, and the extent of increase depended on the polymer content of the powder. The greater increase of solubility corresponded to the highest content of polymer. Both the solid dispersions and the cyclodextrin complexes were able to improve the in vivo bioavailability of the lonidamine when administered per os. Particularly, the AUC of the drug plasma levels was increased from 1.5 to 1.9-fold depending on the type of carrier.     

Stopped flow kinetic-spectrophotometric determination of Diquat in waters

Using the measures of initial reaction rate, a kinetic-photometric method is developed that uses the reaction of Diquat with H2O2 in basic medium. The reaction rate is very high and therefore the stopped-flow mixing technique is required in order to make kinetic measurements. The reaction rate is obtained in 20 s after the reactants are mixed and it allows the simple application of the method proposed to the routine analyses. The sensitivity of the method is very high being the detection limit 0.44 microgmL(-1) and the application range between 1 and 16 microgmL(-1). The time of measure per sample is 90s. The proposed kinetic-photometric method has been applied to the direct determination of this compound in river water, in the water of laundry of the olives, and in a commercial product. The results are very acceptable.     

Optical and structural behaviour of Mn implanted sapphire

Sapphire single crystals were implanted at room temperature with 180 keV manganese ions to fluences up to 1.8 × 10¹⁷ cm⁻². The samples were annealed at 1000 °C in oxidizing or reducing atmosphere. Surface damage was observed after implantation of low fluences, the amorphous phase being observed after implantation of 5 × 10¹⁶ cm⁻², as seen by Rutherford backscattering spectroscopy under channelling conditions. Thermal treatments in air annealed most of the implantation related defects and promoted the redistribution of the manganese ions, in a mixed oxide phase. X-ray diffraction studies revealed the presence of MnAl₂O₄. On the contrary, similar heat treatments in vacuum led to enhanced out diffusion of Mn while the matrix remained highly damaged. The analysis of laser induced luminescence performed after implantation showed the presence of an intense red emission.     

Prevalence and dissemination of Salmonella serotypes along the slaughtering process in Brazilian small poultry slaughterhouses

Salmonella is the leading cause of human foodborne infections in Latin America, and poultry meat is one of the main vehicles. Small poultry slaughterhouses (fewer than 200 birds slaughtered per day) represent an important economic activity in certain regions. The slaughtering process in these abattoirs is manual and rudimentary, and frequently the hygienic conditions are poor. This study reports results of a detailed evaluation of the prevalence of Salmonella serotypes in carcasses, utensils, and environmental samples collected in 60 small Brazilian slaughterhouses. In the second step of the study, one of these slaughterhouses was selected to monitor the dissemination of Salmonella along the slaughtering process. For testing, conventional procedures were used: preenrichment in buffered peptone water (35 degrees C for 24 h), selective enrichment in Selenite-cystine (35 degrees C for 24 h), tetrathionate and Rappaport-Vassiliadis broths (42 degrees C for 24 h), plating on bismuth-sulfite and brilliant green agars (35 degrees C for 24 h), proper biochemical testing, and complete serotyping. Forty-one percent of samples harbored Salmonella spp., including 42% of carcasses, 23.1% of utensils, 71.4% of water, and 71.4% of freezers and refrigerators. Seventeen serotypes were detected. Salmonella Enteritidis predominated (30%), followed by Salmonella Albany (12%), Salmonella Hadar (12%), Salmonella Indiana (10%), and I 4,12:z:- (8%). All samples collected along the slaughtering process in the selected slaughterhouse were Salmonella positive. Five serotypes were detected, including Salmonella Albany, Salmonella Hadar, Salmonella Agona, Salmonella Emek, and Salmonella Indiana. More than 30% of the samples contained more than one serotype, and 12.5% presented three serotypes. The widespread occurrence of Salmonella in small slaughterhouses reinforces the need for implementation of effective control measures.