A solvent-free synthesis of sucrose polyesters

A solvent-free reaction system is described for making sucrose polyesters (SPE) by interesterification of sucrose and long chain fatty acid methyl esters. The process avoids the usual toxic solvents by using a novel two-stage reaction sequence. In the first stage a 3:1 mole ratio of methyl esters to sucrose is reacted in the presence of potassium soaps to form a one phase melt containing mainly lower esters of sucrose. In the second stage more methyl esters are added and reacted to produce SPE in yields up to 90% based on sucrose. Sucrate ion generated in situ with alkali metal hydrides or Na-K alloy proved to be a superior catalyst for formation of sucrose esters during both stages.     

Similarity measures for OLAP sessions

OLAP queries are not normally formulated in isolation, but in the form of sequences called OLAP sessions. Recognizing that two OLAP sessions are similar would be useful for different applications, such as query recommendation and personalization; however, the problem of measuring OLAP session similarity has not been studied so far. In this paper, we aim at filling this gap. First, we propose a set of similarity criteria derived from a user study conducted with a set of OLAP practitioners and researchers. Then, we propose a function for estimating the similarity between OLAP queries based on three components: the query group-by set, its selection predicate, and the measures required in output. To assess the similarity of OLAP sessions, we investigate the feasibility of extending four popular methods for measuring similarity, namely the Levenshtein distance, the Dice coefficient, the tf–idf weight, and the Smith–Waterman algorithm. Finally, we experimentally compare these four extensions to show that the Smith–Waterman extension is the one that best captures the users’ criteria for session similarity.     

Diffusion of water in silica: Influence of moderate stresses

Here we study the diffusive transfer of water into silica glass in the presence of externally applied stresses, and stresses caused by water induced swelling of the glass. By considering the simultaneous action of water penetration into the surface of silica glass and the development of swelling stresses in the water‐penetrated zone, several experimental findings previously published in the literature can be interpreted quantitatively. These include an apparent decrease of the diffusivity with time, an increase of water solubility in the surface region under compressive loading, the opposite effect under tensile loading and a reversal of these two effects deeper within the glass. These expectations are fully met in published experiments carried out to date.     

High content of biogenic amines in Pecorino cheeses

Pecorino refers to Italian cheeses made exclusively from raw or pasteurized ewes' milk, characterized by a high content of fat matter and it is mainly produced in the Middle and South of Italy by traditional procedures. The autochthonous microbiota plays an important role in the organoleptic traits of Pecorino cheese and it can influence biogenic amines (BA) content.     

Diarylheterocycle core ring features effect in selective COX-1 inhibition

The COX-1 isoenzyme plays a significant role in a variety of diseases, as it catalyzes the bioprocesses behind many health problems. Among the diarylheterocycle class of COX inhibitors, the isoxazole ring has been widely used as a central heterocycle for the preparation of potent and selective COX-1 inhibitors such as P6 [3-(5-chlorofuran-2-yl)-5-methyl-4-phenylisoxazole]. The role of the isoxazole nucleus in COX-1 inhibitor selectivity has been clarified by preparing a set of new diarylheterocycles with various heterocycle cores. Replacement of isoxazole with isothiazole or pyrazole gave a drastic decrease in COX-1 inhibitory activity, whereas the introduction of an electron-donating group (EDG) on the N-aryl pyrazole allowed recovery of COX-1 inhibitory activity and selectivity. The EDG-equipped 5-(furan-2-yl)-1-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazole (17) selectively inhibits COX-1 activity (IC(50) =3.4 μM; 28% COX-2 inhibition at 50 μM), in contrast to its inactive analogue, 3-(furan-2-yl)-1-phenyl-5-(trifluoromethyl)-1H-pyrazole, which does not bear the methoxy EDG. Molecular docking studies of compound 17 into the binding site of COX-1 shed light on its binding mode.     

Phase constitution and glass formation in an Au-based alloy

Studies on the phase constitution of annealed master ingots of the Au₄₉Ag_5.5Pd_2.3Cu_26.9Si_16.3 alloy suggest that it is a quinary eutectic and revealed which phases solidify from the melt. The alloy has been amorphized in ribbon form. Ribbon crystallization has been studied in isothermal and continuous heating modes. From such experiments data on the mechanism and kinetics of crystallization have been obtained. Time–temperature–transformation and Continuous Heating Transformations plots for crystallization have been derived from thermal data.     

Comparison of ductile material erosion models combining cutting and deformation components of wear

ABSTRACT

Herein we compare seven models of erosion of ductile materials, considering various combinations including cutting and deformation components of wear. The models were fit to three independent sets of experimental results to verify the quality of fitting based upon the coefficient of determination. The results were discussed especially in terms of the friction component, the adjustment of which could lead to better fitting.     

The homeless use Facebook?! Similarities of social network use between college students and homeless young adults

This research compared technology use among homeless young adults with that of college students as a means of understanding technology use among young adults today; people who have grown up with technology. Specifically, social network site (SNS) usage was assessed for two age-matched young adult samples, one drawn from a large introductory psychology subject pool, and a second from homeless young adults who were approached for participation when they entered metropolitan shelters. Overall, technology use was strikingly similar. These results call for a paradigm shift in researchers’ understanding of technology use and indicate that contemporary young adults sampled across socio-economic class and varying ethnicities are far more similar than prior research would suggest. These results call into question whether the term “digital divide” is useful for describing group differences in technology use as our results suggest the divide has narrowed considerably.     

Constrained deformation of an Al based amorphous alloy by cold rolling

In this work, we report on the mechanisms of deformation and fracture of an Al₈₇Ni₇La₆ amorphous alloys by cold rolling. Ribbons were cold rolled at room temperature embedded in pure Al-foils (volume fraction 20%). Scanning Electron Microscopy observations of the cross section of the deformed samples revealed that, after a few rolling passes, ribbons broke into fragments and formed shear bands because of the load exerted by the ductile Al matrix starting from the roughness on the surfaces. The shear band offset was higher near the fracture surface, suggesting that a stress concentration occurs when the slip of shear band is hindered by the presence of constraint. In ribbons rolled alone elongation above 3% was achieved as well as flattening of the surface roughness.Fracture surfaces of ribbon fragments presented mainly features due to brittle shear and a limited number of veins and filaments suggesting mixed mode of fracture.No formation of crystals in the shear bands was evidenced by Transmission Electron Microscopy and Differential Scanning Calorimetry.     

Experimental assessment of color-rendering indices and color appearance under varying setups

The Color-Rendering Index (CRI) for light source is a quantitative measure of the capability to preserve color appearance of illuminated objects. Recently, CRI has had a renewed interest because of the new LED-based lighting systems. These sources usually have a Color-Rendering Index rather low, but a good preservation of color appearance and a pleasant visual appeal. Various attempts to develop a more reliable new color-rendering index have been done so far, but researchers are still working on the topic. This article presents the open issues related to CRI and discusses some of the approaches available in literature. In order to have a baseline to verify the above points, we present an experiment performed with human observers to assess the appearance preservation of a color under a set of light sources. The test protocol uses 3D reference objects and can be used as an alternative way to assess CRI. The results are then compared with a range of available color rendering indices. The goal is not to make a rank among CRIs, rather to assess their variability relative to human judgment through different setups and light sources.