Mathematical Modeling of Drying Kinetics for Apricots: Influence of the External Resistance to Mass Transfer

The drying curves of halved and deseeded apricots obtained during convective drying at different temperatures (from 50 to 90°C) have been examined, and a diffusional model, solved by a finite elements method, has been proposed to simulate the drying kinetics. The importance of taking into account both the internal and the external resistances to mass transfer when modeling the drying curves is discussed. Due to the geometry of halved apricots as a hemisphere losing water only through the flat section, the mass transfer coefficient (k_c) was not correctly estimated through an empirical correlation. Only the identification of this coefficient from the experimental results allowed an accurate simulation, decreasing the mean relative error from 12.3±3.8% when k_c was calculated through the Pasternak and Gauvin correlation to 2.9±1.0% when k_c was identified.     

Ba(Ti1−xSnx)O3 (x=0.13) Dielectric Ceramics Prepared by Coprecipitation

Fine-grain BaTi_0.87Sn_0.13O₃ (BTS₁₃) powder was synthesized from an oxalate precursor and used to prepare sintered ferroelectric BTS₁₃ ceramics. The evolution of the morphology and structure of a BTS₁₃ precipitate precursor as a function of temperature was analyzed. We compare the sintering behavior as well as the dielectric properties of the BTS₁₃ ceramics obtained using uniaxial and cold isostatic pressing.     

Managing discrimination in selection: The influence of directives from an authority and social dominance orientation.

The authors examined one manner in which to decrease the negative impact of social dominance orientation (SDO), an individual difference variable that indicates support for the "domination of 'inferior' groups by 'superior' groups" (J. Sidanius & F. Pratto, 1999, p. 48), on the selection of candidates from low-status groups within society. Consistent with the tenets of social dominance theory, in 2 studies we found that those high in SDO reported that they were less likely to select a potential team member who is a member of a low-status group (i.e., a White female in Study 1 and a Black male in Study 2) than those low in SDO. However, explicit directives from an authority moderated this effect such that those high in SDO were more likely to select both candidates when authority figures clearly communicated that job performance indicators should be used when choosing team members. Thus, our studies suggest that the negative effects of SDO may be attenuated if those high in SDO are instructed by superiors to use legitimate performance criteria to evaluate job candidates. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A kinetic scheme for an amine-epoxy reaction with simultaneous etherification

The curing reaction of an epoxy resin with a diamine is analyzed, taking into account the possibility of simultaneous etherification. A kinetic scheme is derived and fitted to experimental results for the reaction of commercial bisphenol A diglycidyl ether (BADGE) with diaminodiphenyl sulfone (DDS). Total reaction heat, vitrification curve, and reactivity ratio of secondary to primary amine hydrogens are experimentally characterized. It is shown that the etherification reaction is significant at T > 150°C, at intermediate and high reaction extents when the primary amine has been sufficiently depleted.     

Audio-visual speech asynchrony detection using co-inertia analysis and coupled hidden markov models

This paper addresses the subject of liveness detection, which is a test that ensures that biometric cues are acquired from a live person who is actually present at the time of capture. The liveness check is performed by measuring the degree of synchrony between the lips and the voice extracted from a video sequence. Three new methods for asynchrony detection based on co-inertia analysis (CoIA) and a fourth based on coupled hidden Markov models (CHMMs) are derived. Experimental comparisons are made with several methods previously used in the literature for asynchrony detection and speaker location. The reported results demonstrate the effectiveness and superiority of the proposed new methods based on both CoIA and CHMMs as asynchrony detection methods.     

An Initial Experimental Assessment of the Dynamic Modelling in UML

The goal of this empirical study is to compare the semantic comprehension of three different notations for representing the dynamic behaviour in unified modelling language (UML): (a) sequence diagrams, (b) collaboration diagrams, and (c) state diagrams. Eighteen students of Informatics analysed the three types of diagrams within three different application domains. We performed a 3 × 3 factorial experimental design with repeated measures. The metrics collected were total time and total score. The main conclusion of this study is that the comprehension of the dynamic modelling in object-oriented designs depends on the diagram type and on the complexity of the document. The software project design written in the UML notation is more comprehensible, when the dynamic behaviour is modelled in a sequence diagram. While if it is implemented using a collaboration diagram, the design turns out to be less comprehensible as the application domain, and consequently, the document is more complex.     

Stability of the lipid fraction of milk‐based infant formulas during storage

A study is made of the effects of storage (time and temperature) on the lipid fraction of four milk‐based adapted infant formulas with basically the same composition, though differing in the iron salt added (lactate or sulfate) and/or the vitamin E source (α‐tocopherol or α‐tocopherol acetate). Peroxide value, hydroperoxide C₁₈ percentage and thiobarbituric acid‐reactive substance (TBARS) content were used as indicators of lipid peroxidation. Fat contents remained stable throughout storage. Peroxide values increased from the first storage month and were affected by storage time, although they exhibited irregular behavior. Storage time and temperature affected hydroperoxide percentage, which was seen to be the earliest indicator of lipid oxidation, being measurable in newly manufactured formulas. TBARS values were only affected by storage time. No statistically significant differences were found among the four infant formulas for any of the lipid oxidation indicators.     

The failure of clinical psychology graduate students to apply understood ethical principles.

Surveyed 170 graduate students from 25 American Psychological Association (APA)-approved clinical training programs on what they should do in a hypothetical situation in which a peer/friend is violating the ethical principles stated in APA's Ethical Standards of Psychologists, and then what they would do. It was found that approximately half of these Ss would do less than they believe they should. The need for a thorough, formal, and systematic approach to training in ethics is emphasized. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)