A New Application of the Severity Factor Kinetic Model: Thermal Plasma Treatment of Black Liquor

The kinetic analysis of the treatment of black liquor by a thermal process can be performed in the conventional overall kinetic approach. However, while the detailed reaction mechanism remains unknown, the experimental analysis of black liquor treatment by submerged plasma demonstrates that the operating conditions (catalyst, plasma gas, temperature…) modify the kinetics and render this approach inefficient. The phenomenological approach based on the severity factor developed for the kinetic analysis of lignocellulose decomposition, is then proposed as an alternative to the conventional approach. The 3‐parameters model is validated for decomposition of formic acid and for sulfur oxidation.     

Delineating the construct network of the Personnel Reaction Blank: Associations with externalizing tendencies and normal personality.

Integrity testing has long been utilized in personnel selection to screen for tendencies toward counterproductive workplace behaviors. The construct of externalizing from the psychopathology literature represents a coherent spectrum marked by disinhibitory traits and behaviors. The present study drew on a sample of male and female undergraduates to examine the construct network of the Personnel Reaction Blank (PRB; H. G. Gough, R. D. Arvey, & P. Bradley, 2004), a measure of integrity, in relation to externalizing as well as normal-range personality constructs assessed by the Multidimensional Personality Questionnaire (MPQ; A. Tellegen & N. G. Waller, 2008). Results revealed moderate to strong associations between several PRB scales and externalizing, which were largely accounted for by MPQ traits subsumed by Negative Emotionality and Constraint. After accounting for MPQ traits in the prediction of externalizing, a modest predictive increment was achieved when adding the PRB scales, particularly biographical indicators from the Prosocial Background subscale. The findings highlight externalizing as a focal criterion for scale development in the integrity testing literature and help delineate the construct network of the PRB within the domains of personality and psychopathology. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Treatment of industrial glycerol from biodiesel production by adsorption operation: kinetics and thermodynamics analyses

Abstract

Equilibrium, thermodynamic, and kinetic analyses of the pigments adsorption of the industrial glycerol onto activated charcoal were performed. As the pigments concentration was not known, then, a relative adsorption capacity was defined using absorbance values measured in a spectrophotometer at a wavelength of 265?nm. Kinetic study showed that about 60?s were needed to reach equilibrium conditions. Relative adsorption capacity reached 8?g^?1 for 1% of adsorbent amount (w/w). Adsorption enthalpy was of –17.63?kJ mol^?1, while for isosteric heat values were obtained between –7.39 and –18.46?kJ mol^?1. The mathematical methodology used for the parameters determinations proved to be robust and able to express the relationships of kinetics, equilibrium and thermodynamics. Enthalpy values obtained by Van't Hoff method was confirmed by isosteric heat calculation, evidencing that this methodology can be used for systems whose compositions are unknown, but detectable by indirect form.     

Effect of active films incorporated with montmorillonite clay and α‐tocopherol: Potential of nanoparticle migration and reduction of lipid oxidation in salmon

Fat‐rich fish such as salmon are highly susceptible to lipid oxidation, which affects the quality of the product. The compound α‐tocopherol is widely used as an antioxidant added directly to food or through the incorporation in active packaging besides having activity of vitamin E, which is an essential nutrient to the human body absorbed from food. The objective of this paper was to evaluate the montmorillonite (MMT15A) and α‐tocopherol migration potential and antioxidant effect of chitosan/MMT15A/α‐tocopherol active films on reduction of lipid oxidation in fresh salmon. Chitosan films incorporated with MMT15A (0 and 1 g/100 g) and α‐tocopherol (0, 10, and 15 g/100 g) were applied on the fresh salmon for 8 days. Samples of salmon wrapped in films 3 and 6 (10% tocopherol and 1% MMT15A + 15%tocopherol, respectively) showed the lower values of thiobarbituric acid reactive substances (TBARS) at eighth storage day at 4°C. Film 6 (1% MMT15A and 15% tocopherol) showed better result on reduction in water vapour transmission rate (WVTR) and controlled release of tocopherol. All the films containing MMT15A presented migration of minerals (Mg and Si) for the salmon during the 8 days. Thus, the use of this film for release of active substances is a promising alternative for application as food packaging in order to obtain nutritionally fortified foods and inhibit oxidation reactions.     

Relation among anthropometric measures and the blood pressure values in Brazilian students

The evaluation of blood pressure and anthropometric measurements is important for evaluating the health of children and teenagers, since cardiovascular abnormalities are becoming more and more common in this population. The objective of this study was to analyze the correlation between anthropometric measurements and arterial pressure taking gender, age and the practice of physical activities into consideration. A cross sectional study was carried out in a school in the city of Fortaleza, Ceará, Brazil, in a sample of 122 students of 6-18 years of age. Data was collected on a specific form and included sociodemographic data, anthropometric evaluation, measurement of arterial pressure and the practice of physical activity. Three measurements were taken of each anthropometric variable and arterial pressure, and the respective means were calculated. Data were processed and analyzed using the SPSS software program, version 13.0. Significance was established at 5% (p < 0.05). A correlation was identified between arterial pressure and tricipital skinfold thickness. No statistically significant differences were found between the mean anthropometric measurements and the presence of high blood pressure. A correlation was found between body mass index and abdominal and subscapular skinfold thickness and between body mass index and waist and hip circumference. Physical activity had no effect on anthropometric measurements. Females had a higher mean tricipital and abdominal skinfold thickness than males. This study confirms the influence of the variables of gender and age on the anthropometric measurements evaluated. In particular, tricipital skinfold thickness was correlated with systolic arterial pressure.     

Evaluation of four high velocity thermal spray guns using WC-10% Co-4% Cr cermets

Four high velocity thermal spray guns were evaluated in the production of 10% Co-4% Cr tungsten carbide (WC) cermets. Three high velocity oxygen fuel guns (JP-5000, JP-5000ST, and Diamond Jet [DJ]-2700) and one plasma gun (Axial III) were used to spray the same angular, agglomerated, and crushed WC-10Co-4Cr powder. The DPV-2000 was used to monitor the in-flight velocity and temperature of the WC cermet-sprayed particles. From those values, spray conditions were selected to produce coatings that were evaluated in terms of porosity, hardness, and deposition efficiency. Results show that the plasma Axial III provides the highest particle temperature, between 2000 °C and 2600 °C, depending on the spray conditions. The JP-5000 imparts the highest velocity to the particles, between 550 and 700 m/s, depending on the spray conditions. The ST version of the JP-5000 provides the same velocity as the standard version but with lower particle temperature. The DJ-2700 sprays particles with temperature and velocity between those of the JP-5000 and the Axial III. Minimum porosity values of 2.1%, 3.7%, and 5.3%, respectively, were obtained for the JP-5000, the DJ-2700, and the Axial III guns. The porosity and carbide degradation are found to depend mostly on the particle velocity and temperature, respectively. The values for the Vickers microhardness number (200g) ranged from 950 to 1250. Measurements of the deposition efficiency indicated a variation between 10% and 80%, depending on the spray conditions and the gun used.