Effect of growing area on pigment and phenolic fractions of virgin olive oils of the arbequina variety in Spain

The purpose of this investigation was to study differences in the chlorophyll, carotenoid, and phenolic fractions of virgin olive oils from the Arbequina variety cultivated in different olive growing areas of Spain. Virgin olive oil from Lleida was less heavily pigmented, and these oils showed more negative values for the ordinate a^* (of the CIELAB colorimetric system). Pheophytin a was the major chlorophyll pigment, and lutein was the major component of the carotenoid fraction in all oils analyzed. The chlorophyll a concentration in virgin olive oils from Lleida was 700 μg kg⁻¹, but was 175 μg kg⁻¹ in oils from Jaén, and 200 μg kg⁻¹ in oils from Tarragona. Finally, the chlorophyll a/chlorophyll b ratio was 9 in oils from Lleida and around 0.6 in the other two Arbequina olive oils. In relation to the phenolic fraction, the hydroxytyrosol and tyrosol contents were significantly higher in olive oils from Jaén (grown at higher altitude and precipitation rates). The secoiridoid derivatives showed a significantly higher concentration in olive oils from Tarragona, probably due to the low altitude where they grow, and finally the ratio of (dialdehydic form of elenolic acid linked to tyrosol)/lignans had a value of 1.4 in olive oils from Lleida, whereas this value was around 0.7 in the other Arbequina olive oils.     

25th Anniversary Article: Rise to Power – OPV‐Based Solar Parks

A solar park based on polymer solar cells is described and analyzed with respect to performance, practicality, installation speed, and energy payback time. It is found that a high voltage installation where solar cells are all printed in series enables an installation rate in Watts installed per minute that far exceed any other PV technology in existence. The energy payback time for the practical installation of polymer solar cell foil on a wooden 250 square meter platform in its present form is 277 days when operated in Denmark and 180 days when operated in southern Spain. The installation and de‐installation rate is above 100 m min^?1, which, with the present performance and web width, implies installation of >200 W min^?1. In comparison, this also exceeds the overall manufacturing speed of the polymer solar cell foil with a width of 305 mm which is currently 1 m min^?1 for complete encapsulated and tested foil. It is also significant that simultaneous installation and de‐installation which enables efficient schemes for decommissioning and recycling is possible. It is highlighted where research efforts should most rationally be invested in order to make grid electricity from OPV a reality (and it is within reach).     

Compressed vertical partitioning for efficient RDF management

Knowledge and Information Systems - The Web of Data has been gaining momentum in recent years. This leads to increasingly publish more and more semi-structured datasets following, in many cases,...     

Molecular fluorinated alumoxanes: One step towards well-defined fluorinated alumina

The unprecedented molecular alumoxane [{LAl(F)}₂(μ-O)] (2) is easily accessible from the reaction between [{LAl(H)}₂(μ-O)] (1) and the mild fluorinating agent Me₃SnF. Furthermore, the controlled hydrolysis of 2 led to the preparation of the binuclear aluminum hydroxyfluoride [{LAl(F)(μ-OH)}₂] (3) in a straightforward manner. The compounds were characterized by spectroscopic techniques (IR, EI–MS, solid state MAS NMR (¹³C and ²⁷Al), solution NMR (¹H, ¹³C, ¹⁹F and ²⁷Al)) and in the case of 3, through X-ray diffraction studies. Compound 3 represents the first example of a molecular aluminum hydroxyfluoride fully structurally characterized.     

Synthesis,characterization and functional properties of galactosylated derivatives of chitosan through amide formation

Low molecular weight chitosan (LMWC) and chitooligosaccharide (COS) derivatives were obtained by the introduction of lactobionic acid (LA) through amide formation, obtaining different complexes COS-LA and LMWC-LA (1–5), with a degree of substitution (DS) between 3 and 16%. The synthesis of these derivatives was monitored by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), High-Performance Liquid Chromatography-Size Exclusion Chromatography (HPLC-SEC) and proton Nuclear Magnetic Resonance (¹H NMR) analyses. Different functional properties, solubility, water binding capacity (WBC) and fat binding capacity (FBC), as well as the antioxidant activity (DPPH radical scavenging activity) of these derivatives were evaluated. Solubility, WBC and FBC increased in all of the chitosan derivatives respect to those of the native LMWC or COS. The most substituted derivative (LMWC-LA1, DS 15%) presented the highest value of solubility (14.4 mg/mL) while the highest levels of WBC and FBC were obtained for the derivative with a DS of 3% (LMWC-LA5; 4730% and 7100%, respectively). COS and COS-LA presented the best DPPH scavenging abilities, as shown by their low values of EC₅₀ (1.29 and 3.45 mg/mL, respectively). An inverse relationship between the DS of chitosan derivatives and antioxidant activity was observed. LMWC-LA5 (3% DS) was the derivative with the highest DPPH activity, being higher than LMWC in all the concentrations assayed (10.2–14.3% and 6.9–13.7%, respectively). Due to their enhanced functional properties, these chitosan derivatives could be considered as very promising for their future use as additives in the food industry (i.e. to bind fat and cholesterol or avoid hardening of foods).     

Changes in contrast thresholds with mean luminance for chromatic and luminance gratings: A reexamination of the transition from the DeVries–Rose to Weber regions

We have examined the influence of the mean luminance level on the detection thresholds for luminance and red–green chromatic gratings for three different spatial frequencies. The changes in detection thresholds according to the mean luminance level reflect the two different regions, the DeVries–Rose and Weber ranges, found in previous studies. The results for luminance gratings suggest that the transition luminance is proportional to the spatial frequency of the grating. Predictions based on the constant‐flux hypothesis indicate, however, that the transition luminance is proportional to the square of the spatial frequency of the grating and so do not describe the distributions of luminance contrast thresholds adequately. For chromatic gratings, we obtained the same transition luminance for the two lowest spatial frequencies, showing that luminance and chromatic mechanisms behave differently as far as the dependence of the transition luminance on spatial frequency is concerned. Our results suggest that the transition luminance is related to the peak spatial frequency of visual mechanisms that respond to luminance and chromatic gratings. © 2004 Wiley Periodicals, Inc. Col Res Appl, 29, 177–182, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20003     

Multi‐point monitoring of cross‐linking reactions

The feasibility of deploying optical fiber sensors to obtain qualitative and quantitative information on the cross‐linking characteristics of thermosetting resin systems has been demonstrated by a number of researchers. This article is concerned with the demonstration of a low‐cost fiber‐optic Fresnel sensor system for monitoring the cross‐linking reactions at multiple locations. Cross‐linking reactions can be influenced by a number of parameters including the stoichiometry of the resin and hardener, and the heat‐transfer rates in and out of the preform as a function of the cross‐section of the preform. In situations where there is a variation in the thickness of the preform or when large components are processed, a facility to monitor the cross‐linking reactions at multiple locations will be valuable because the rate and extent of the cross‐linking can be inferred. In this article, six Fresnel sensors were immersed in individual vials containing an epoxy/amine resin system and processed (cross‐linked) in an air‐circulating oven. One additional vial with a Fresnel sensor immersed in the neat epoxy resin (no hardener) was co‐located in the oven to enable the effect of temperature to be monitored. The feasibility of using the multiplexed Fresnel sensors for cure monitoring was demonstrated successfully. The sensors in the post‐cross‐linked samples were used to study the effects of heating and cooling cycles. The feasibility of detecting the glass transition temperature using the Fresnel sensor is discussed along with the factors that give rise to variability in the output Fresnel signals. © 2014 The Authors. Journal of Applied Polymer Science Published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41088.     

Human and organizational error as a basis for processreengineering: with applications to systems integration planning andmarketing

This paper presents the results of research on how assessment of the incidence and causes of human and organizational error in implementing processes can be utilized as a partial basis for the reengineering of organizational structures and processes. A systems integration environment was used as a site for empirical observation. A model was developed for the life cycle process of preparing a systems integration proposal involving integration of commercial-off-the-shelf (COTS) software and hardware, services, and value-added products. This model was used as a basis for analysis of errors committed during the life cycle process. From this analysis follows development of strategies for workflow and process reengineering. The identified approach can form part of a coordinated effort to reengineer vital processes within an organization with minimization of specific errors as a primary goal in efforts that involve the planning and engineering of systems     

Galactooligosaccharides derived from lactose and lactulose: influence of structure on Lactobacillus, Streptococcus and Bifidobacterium growth

The effect of structure on the fermentative properties of potential prebiotic trisaccharides derived from lactulose like 6′-galactosyl-lactulose (β-d-galactopyranosyl-(1 → 6)-β-d-galactopyranosyl-(1 → 4)-β-d-fructopyranose), 4′-galactosyl-lactulose (β-d-galactopyranosyl-(1 → 4)-β-d-galactopyranosyl-(1 → 4)-β-d-fructopyranose), and 1-galactosyl-lactulose (β-d-galactopyranosyl-(1 → 4)-β-d-fructopyranosyl-(1 → 1)-β-d-galactopyranose); and from lactose like 4′-galactosyl-lactose (β-d-galactopyranosyl-(1 → 4)-β-d-galactopyranosyl-(1 → 4)-β-d-glucopyranose) and 6′-galactosyl-lactose (β-d-galactopyranosyl-(1 → 6)-β-d-galactopyranosyl-(1 → 4)-β-d-glucopyranose), has been assessed in vitro. Fermentations with twelve pure strains of Lactobacillus, Streptococcus and Bifidobacterium were carried out using the purified trisaccharides as the sole carbon source, and bacteria growth was evaluated at 600 nm by means of a microplate reader during 48 h. Maximum growth rates (μ_max) and lag phase were calculated. In general, all the strains tested were able to utilize lactulose and pure trisaccharides derived from lactulose and lactose when they were used as sole carbon source. Nonetheless, glycosidic linkage and/or the monosaccharide composition of the trisaccharides affected the individual strains lag phase, cell densities and growth rates. A general preference towards β-galactosyl residues β(1-6) and β(1-1) linked over those β(1-4) linked was observed, and some strains showed higher cell densities and speed of growth on 6′-galactosyl-lactulose than on 6′-galactosyl-lactose. This is the first study of the effect of lactulose-derived oligosaccharides on pure culture growth which shows that transglycosylation of lactulose allows for obtaining galactooligosaccharides with new glycosidic structures and would open new routes to the synthesis of compounds with potential prebiotic effects.