Hydrogen permeation through Pd–Ag membranes: Surface effects and Sieverts' law

Metal membranes mainly made of Pd alloys can be applied in membrane reformers for ultrapure hydrogen production from hydrocarbons and alcohols.     

A Dynamic Model of a Boundedly Rational Consumer with a Simple Least Squared Learning Mechanism

Moving from a model with a boundedly rational consumer (Naimzada and Tramontana, Journal of Analytical and Institutional Economics 25:59–94, 2008), characterized by a gradient-like decisional process in which, under particular parameters conditions, the asymptotical convergence to the optimal choice does not happen, in the present work we prove that with endogenous reactivity parameter, the consumer becomes able to learn from the past and then his consumption choice converges to the rational one.     

Occurrence and evolution of amino acids during grape must cooking

A study of the involvement of amino acids and other amino compounds in sugar degradation during must cooking was pursued. Two white musts (Trebbiano toscano and Spergola) and a red one (Lambrusco) were cooked by means of a lab-scale equipment emulating the real process.     

BendyLights: Artistic Control of Direct Illumination by Curving Light Rays

In computer cinematography, artists routinely use non‐physical lighting models to achieve desired appearances. This paper presents BendyLights, a non‐physical lighting model where light travels nonlinearly along splines, allowing artists to control light direction and shadow position at different points in the scene independently. Since the light deformation is smoothly defined at all world‐space positions, the resulting non‐physical lighting effects remain spatially consistent, avoiding the frequent incongruences of many non‐physical models. BendyLights are controlled simply by reshaping splines, using familiar interfaces, and require very few parameters. BendyLight control points can be keyframed to support animated lighting effects. We demonstrate BendyLights both in a realtime rendering system for editing and a production renderer for final rendering, where we show that BendyLights can also be used with global illumination.     

The effect of the addition of Y2O3 to Ni/α-Al2O3 catalysts on the autothermal reforming of methane

The addition of Y₂O₃ to Ni/α-Al₂O₃ catalysts was investigated by BET surface area measurements, hydrogen chemisorption, X-ray diffraction, UV–vis diffuse reflectance spectroscopy, X-ray fluorescence, temperature programmed reduction, temperature programmed oxidation and cyclohexane dehydrogenation. Autothermal reforming experiments were performed in order to evaluate the methane conversion and proceeded through an indirect mechanism consisting of total combustion of methane followed by CO₂ and steam reforming generating the synthesis gas. The Y₂O₃·Al₂O₃ supported catalysts presented better activity and stability in autothermal reforming reaction. Temperature programmed oxidation analysis demonstrated that the addition of Y₂O₃ resulted in a change of the type or the location of coke formed during reaction. None of the prepared catalyst presented deactivation by sintering under the tested conditions. The improved stability of supported catalysts Y₂O₃·Al₂O₃ was the result of minimizing the formation of coke on the surface of nickel particles.     

A Novel Assembly of Substituted Pyrroles by Acid‐Catalyzed Sequential Three‐Component Reaction of Amines,Alkynoates, and 1,2‐Diaza‐1,3‐dienes

A novel protocol for the assembly of polysubstituted pyrroles has been developed through the acid‐catalyzed, sequential three‐component reaction of primary aliphatic amines, alkynoates and 1,2‐diaza‐1,3‐dienes (DDs). This methodology proceeds with complete chemo‐/regioselectivity involving first formation of an enamino ester intermediate, in situ Michael addition with azo‐ene compounds and subsequent intramolecular ring closure.     

Cinchona Alkaloid‐Catalyzed Enantioselective Direct Aldol Reaction of N‐Boc‐Oxindoles with Polymeric Ethyl Glyoxylate

The first enantioselective direct aldol addition of N‐Boc‐oxindoles to polymeric ethyl glyoxylate is presented. The reaction is performed by using as low as 0.1 mol% (DHQ)₂PHAL and gives access to α‐hydroxycarboxylate derivatives bearing adjacent secondary alcohol and quaternary stereocenters with high levels of diastereo‐ and enantiocontrol. The use of ethyl glyoxylate in its polymeric form represents an important advantage for synthetic applications and allows us to directly install a C₂ unit ready to be converted in useful building blocks. A further one‐pot protection/deprotection sequence catalyzed by Zn(ClO₄)₂⋅6 H₂O preserved the α‐hydroxycarboxylates from racemization by means of a parasitic alcohol‐catalyzed retroaldol reaction.     

Effect of Residual Water Content on the Physico-Chemical Properties of Sucralfate Dried Gel Obtained by Microwave Drying

The purpose of this study was to investigate the physico-chemical characteristics of sucralfate humid gel dried by microwaves, in relation to the residual water content. Differential scanning calorimetry (DSC) allowed for the determination of the water state in sucralfate samples. Fourier-transform infrared (FT-IR) spectroscopy was used to monitor the changes in sucralfate gel structure induced by the microwave drying. A boundary value of total water content for sucralfate gel samples was found at 42% (w/w). Below this value only bound water was present, whereas above this value, the increase in total water was due to free water. In the physical form of gel, the strength of the coordination between sulfate anions and the positively charged aluminum hydroxide was dependent on the residual water content. The study of the sedimentation behavior of water suspensions prepared with dried sucralfate allowed for the evaluation of the retention of gel properties. We found that the microwave drying process affected the sedimentation of sucralfate dried gel suspensions independent of the residual water content: when suspensions were prepared from sucralfate dried gel powders containing more than 42% (w/w) of residual water, the sedimentation ratio was higher than 0.9. The non-gel powder suspension showed a sedimentation ratio of 0.68 ± 0.02, whereas the sucralfate humid gel suspension did not sediment.     

Lipase entrapment in PVA/Chitosan biodegradable film for reactor coatings

This study reports the development and characterization of novel biodegradable film, based on chitosan and polyvinyl alcohol containing lipase entrapped. The films showed a thickness of 70.4 and 79 μm to PVA/Chitosan and PVA/Chitosan/Lipase, respectively. The entrapment of lipase in PVA/Chitosan film resulted in increasing of 69.4% tensile strength (TS), and 52.4% of elongation. SEM images showed the formation of a continuous film, without pores or cracks. The lipase entrapment efficiency was estimated in 92% and the films were repeatedly used for 25 hydrolytic cycles, maintaining 62% of initial activity. The PVA/Chitosan/Lipase film was used for olive oil hydrolysis of high performance. These results indicate that PVA/Chitosan/Lipase is a promising material for biotechnology applications such as triacylglycerol hydrolysis and biodiesel production.