Catalysts based on supported 12-molybdophosphoric acid

Catalysts preparation by equilibrium adsorption of 12-molybdophosphoric acid in water–ethanol solutions onto silica, titania, carbon and alumina is studied. The solute/support interaction follows the decreasing order: alumina, carbon, silica and titania. It is observed that the molybdophosphoric acid keeps its Keggin-type structure after being supported at room temperature on all supports. This species is stable up to 500°C on silica, 400°C on titania or carbon and 250°C for alumina. The acidity of the supported heteropoly acid decreases in the following order: silica>titania>carbon>alumina. This revised version was published online in July 2006 with corrections to the Cover Date.     

Estimation of potentially available protein in infant starting formulas for term and preterm neonates

Sixteen milk-based starting formulas were analyzed with the aim of calculating their "true protein" content and assessing "in vitro" protein digestibility, in order to estimate levels of potentially available protein. Ten of them were designed for term infants: 7 had a casein:whey protein ratio 40:60 (adapted formulas) and 3 a ratio 80:20 (non-adapted); the 6 remaining formulas (all adapted) were for preterm infants. Nitrogen was determined by the Kjeldahl method. True protein was calculated as (total N--non-protein N) x 6.25. NPN was determined in the soluble fraction, after protein precipitation with 24% trichloroacetic acid and centrifugation. Digestibility was assessed by digestion with pepsin and pancreatin, and defined as the increase in non-protein N after enzymatic digestion. Values for true protein were from 1.3 to 2.3 g/dL and for non protein N, from 4.5 to 13.7%. Digestibility values varied between 59.0 and 92.5%; an inverse trend was observed between protein digestibility and protein content. Considering both the "true protein" levels and their digested proportions, all preterm and 60% of the term formulas would present potentially available amounts below those recommended. These observations constitute an alert, even though this method of assessing "in vitro" protein digestibility represents only an approximation to physiological processes; however, it could be useful in order to evaluate the intensity of the heat treatments to which these formulas were subjected. On the other hand, since NPN allows the estimation of the true protein provided by the formulas, either its percentage or the true protein content could be included on the label.     

Characterization of the Sonar Signals Benchmark

We study the classification of sonar targets first introduced by Gorman & Sejnowski (1988). We discovered that not only the training set and the test set of this benchmark are both linearly separable, although by different hyperplanes, but that the complete set of patterns, training and test patterns together, is also linearly separable. The distances of the patterns to the separating hyperplane determined by learning with the training set alone, and to the one determined by learning the complete data set, are presented.     

Waterborne polyurethane nanocomposites based on vegetable oil and microfibrillated cellulose

This work analyzes the differences in the final properties of two waterborne polyurethanes (WBPU) prepared with two macrodiols of different chemical structure, but similar molecular weight, as well as the variations caused by incorporating low percentages of microfibrillated cellulose nanocrystals. One of the polyurethanes was based on a synthetic but biodegradable precursor (polycaprolactone diol, PCL) and a second one based on a bio‐based macrodiol derived from castor oil (CO1). The bio‐based material presented higher mechanical properties at room temperature than the synthetic one, with the Young's modulus (MPa) ranging from 2.23 ± 0.09 to 84.88 ± 0.96 for the PCL and bio‐based WBPUs, respectively. Additionally, the PCL‐based WBPU showed to be more sensitive to the incorporation of cellulose than the bio‐based WBPU, and it also suffered changes during time due to delayed crystallization. The behavior of the two systems were compared and related to the different structure of the macrodiols that led to different interfacial interactions. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44207.     

On the existence of the nonlinear weighted least squares estimate for a three-parameter Weibull distribution

The problem of nonlinear weighted least squares fitting of the three-parameter Weibull distribution to the given data (w_i,t_i,y_i), i=1,…,n, is considered. The part w_i>0 of the data stands for the data weights. It is shown that the best least squares estimate exists provided that the data satisfy just the following two natural conditions: (i) 0<t₁<t₂<?<t_n and (ii) 0<y₁<y₂<?<y_n<1. To support this, an illustrative numerical example is given.     

Comparison procedure of predicting the time to default in behavioural scoring

The paper deals with the problem of predicting the time to default in credit behavioural scoring. This area opens a possibility of including a dynamic component in behavioural scoring modelling which enables making decisions related to limit, collection and recovery strategies, retention and attrition, as well as providing an insight into the profitability, pricing or term structure of the loan. In this paper, we compare survival analysis and neural networks in terms of modelling and results. The neural network architecture is designed such that its output is comparable to the survival analysis output. Six neural network models were created, one for each period of default. A radial basis neural network algorithm was used to test all six models. The survival model used a Cox modelling procedure. Further, different performance measures of all models were discussed since even in highly accurate scoring models, misclassification patterns appear. A systematic comparison ‘3 + 2 + 2’ procedure is suggested to find the most effective model for a bank. Additionally, the survival analysis model is compared to neural network models according to the relative importance of different variables in predicting the time to default. Although different models can have very similar performance measures they may consist of different variables. The dataset used for the research was collected from a Croatian bank and credit customers were observed during a 12-month period. The paper emphasizes the importance of conducting a detailed comparison procedure while selecting the best model that satisfies the users’ interest.     

Mineral bioaccessibility in yerba mate (Ilex paraguariensis St) infusions and mixtures with iron fortified milk

The bioaccesibility of various minerals in infusions of yerba male (mate cocido) and preparations with Fe-fortified milk was assessed to determine the influence of the infusions on the potential bioavailability of intrinsic minerals and fortified Fe. The dialyzability (D) of iron, calcium, magnesium and zinc was evaluated, as indicator of bioaccesibility in milk samples fortified with ferrous sulfate (FS), ferric bisglicinate GF) and EDTANaFe. Dialyzability was also evaluated in mixtures of milk with mate cocido and in infusions cooked with Fe-fortified milk. In each case the effect of ascorbic acid (AA) in a ratio Fe: AA 1:4 was studied. In the mate cocido FeD was zero and increased to 15% with the addition of AA. The FeD in milk with SF, BGF and EDTANaFe (1.2, 1.0 and 27.4 respectively), increased with the addition of AA to 2.9, 3.5 and 24.8. The FeD in the mixture milk: mate cocido was 4.7%, 5.7% and 31.2% for SF, BGF and EDTANaFe respectively. With the addition of AA was 13.5%, 13.7% and 25.7%. In infusions cooked with SF fortified milk, the values were lower than those of the mixture. The CaD did not show significant changes in Fe fortified milk and its preparations with yerba mate, while the MgD and ZnD only showed a significant reduction in infusion cooked with Fe-fortified milk. The use of infusions of yerba mate does not provide significant amounts of minerals. However, its use in mixtures with milk will not adversely affect the availability of Fe in that matrix.     

Epoxy-based divinyl ester resin/styrene copolymers: Composition dependence of the mechanical and thermal properties

Epoxy-based divinyl ester resins (DVER) were obtained by reacting diglycidyl ether of bisphenol A (DGEBA) with methacrylic acid (MA) and characterized by FTIR and ¹H-NMR spectroscopies and gel permeation chromatography (GPC). The densities and viscosities of the DVER in styrene (S) solutions were measured at different temperatures, 25, 40, and 60°C and compositions, 3.4 to 100% by weight of styrene. Dynamic mechanical measurements (DMA) and differential scanning calorimetry (DSC) were used to determine the glass transition temperatures of the homopolymers and the DVER/S copolymers: 20, 40, 60, and 80% by weight of styrene. The values obtained are in the range limited by the homopolymers glass transition, 100°C for polystyrene and 173°C for the cured DVER. The data were well fitted if two contributions to the glass transition are taken into account: the “linear copolymer” contribution (Fox eq.) and the “crosslinking” contribution (Nielsen model). Uniaxial static compression tests were carried out to determine the modulus, yield stress, and ultimate stress in samples with different compositions. All the mentioned properties decrease with an increase in the styrene concentration in the final copolymer. It was found that the volumetric contraction during curing increases with styrene concentration. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1059–1066, 1997     

Do low-numeracy people avoid shared decision making?

Objectives: Doctors have been increasingly encouraged to involve patients in decision making rather than pursuing the paternalistic model in which they make the decisions for their patients. But do patients want to participate in making decisions about their health? Is there a relationship between their preferences for shared decision making and numeracy skills? Are those preferences different in countries with different medical systems, and for different age groups? Extant studies cannot answer these questions because most are based on nonprobabilistic, highly selective patient samples that prevent generalizations to a broader population. Design: In a survey on probabilistic national samples in the United States and Germany, we interviewed participants with low numeracy skills (Germany: n = 127, mean numeracy = 37; United States: n = 117, mean numeracy = 36) and high numeracy skills (Germany: n = 133, mean numeracy = 96; U.S.: n = 121, mean numeracy = 91). Main Outcome Measures: Usual and preferred role in medical decision making. Results: A significant number of people with low numeracy in both the United States (35%, SE = 8.2) and Germany (30%, SE = 6.1) preferred to be more passive than they currently were. High-numeracy people, in contrast, were mostly satisfied with their current role. On average, Americans were more active than Germans. Middle-aged participants preferred to be more active compared to both younger and older ones. Conclusions: Shared decision-making preferences are related to numeracy skills, country, and age. Education efforts to increase numeracy, as well as using nonquantitative communication formats, may foster involvement of low-numeracy patients in decisions about their health. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Poly(methyl methacrylate)‐modified vinyl ester thermosets: Morphology,volume shrinkage,and mechanical properties

Thermoset materials obtained from styrene/vinyl ester resins of different molecular weights modified with poly(methyl methacrylate) (PMMA) were prepared and studied. Scanning electron microscopy and transmission electron microscopy micrographs of the fracture surfaces allowed the determination of a two‐phase morphology of the modified networks. Depending on the molecular weight of the vinyl ester oligomer, the initial content of the PMMA additive, and the selected curing temperature, different morphologies were obtained, including the dispersion of thermoplastic‐rich particles in a thermoset‐rich matrix, cocontinuous structures, and the dispersion of thermoset‐rich particles in a thermoplastic‐rich matrix (phase‐inverted structure). Density measurements were performed to determine the effect of the PMMA‐modifier concentration and curing temperature on the volume shrinkage of the final materials. The development of cocontinuous or thermoplastic‐rich matrices was not too effective in controlling the volume shrinkage of the studied vinyl ester systems. The evaluation of the dynamic mechanical behavior, flexural modulus, compressive yield stress, and fracture toughness showed that the addition of PMMA increased the fracture resistance without significantly compromising the thermal or mechanical properties of the vinyl ester networks. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007