Optimized allylamine deposition for improved pluripotential cell culture

Deposition of allylamine (ALL) by plasma enhanced chemical vapor deposition has been optimized on silicon based models. Simultaneous energy recoil detection analysis and Rutherford backscattering spectra show that 100 W deposition is ideal in terms of polymerized film formation and H content while, lower or higher power induce reduced film retention or excessive cross linking, respectively. Surface composition of the ALL film was further probed by X-ray photoelectron spectroscopy revealing a monocomponent N 1s spectrum compatible with the presence of primary amines. Optimized ALL films were applied to polycaprolactone (PCL) surfaces after Ar plasma activation with implications in the chemistry and wettability of this biocompatible polymer. Human mesenchymal stem cells (hMSCs) were cultured on ALL coated PCL surface and controls. ALL functionalized PCL was found to be especially attractive for the formation of confluent monolayers of hMSCs after 72 h of culture.     

Effects of salt mixtures on Spanish green table olive fermentation performance

This work investigates the effect of sodium, potassium, and calcium chloride salts on the performance of Spanish green table olive fermentation using a simple centroid mixture design. The presence of calcium chloride hindered the diffusion of all sugars and delayed the period required to reach their respective maximum concentrations in brines. Such effects can prevent tumultuous processes and gas pocket spoilage. Acetic acid was present at low concentrations in all treatments but was not generated during fermentation. The production rate of lactic acid was either decreased or delayed by the presence of calcium chloride but adequate final conditions were always reached. The chemometric analysis classified treatments into groups according to the presence of calcium chloride and disclosed a stimulating effect of potassium on lactic acid production. Therefore, these techniques can be a useful tool to investigate olive fermentation performance. According to the results, acceptable Spanish green table olives can be produced using salt mixtures, with the subsequent reduced sodium content in the final products. The results obtained in this study could also be of interest for other fermented vegetables.     

Evaluation of table olive by‐product as a source of natural antioxidants

The main by‐product from the table olive canning industry is the stone with some residual olive flesh. The purpose of this study was to evaluate the composition – phenolic compounds (hydroxytyrosol, tyrosol and oleuropein) and tocopherol – and the antioxidant activity in different fractions (flesh, stone and seed) from the table olive by‐product and the whole by‐product. The highest amounts of phenolic compounds (1710.0 ± 33.8 mg kg^?1) as well as the highest antioxidant activity (8226.9 ± 9.9 hydroxytyrosol equivalents mg kg^?1) were obtained in the seed. The highest amounts of hydroxytyrosol (854.8 ± 66.0 mg kg^?1) and tyrosol (423.6 ± 56.9 mg kg^?1) were found in the whole by‐product from the pepper stuffed olives, while the stone without seed had the maximum oleuropein content (750.2 ± 85.3 mg kg^?1). α‐Tocopherol values were between 79.8 ± 20.8 mg kg^?1 in the seed of the olive stone and 6.2 ± 1.2 mg kg^?1 in the whole by‐product from the anchovy‐stuffed olives. In light of the results obtained, it would seem possible to use table olive by‐product as a source of natural antioxidants in foods, cosmetics or pharmaceutical products, thus contributing to diminishing the environmental impact of table olive by‐product and to its revalorisation.     

Design of an electronic system and its application to electronic tongues using variable amplitude pulse voltammetry and impedance spectroscopy

Electronic equipment (IDM-1) especially designed for the application of voltammetric and impedometric electronic tongues is described. For impedance spectroscopy the equipment permits the generation of sinusoidal signals with a frequency in the range of 1 Hz to 1 MHz and programmable amplitude up to 1 Vpp. For voltammetry the IDM-1 equipment generates a sequence of up to 32 pulses with an amplitude that can be configured for each of the pulses in the range [−0.5; +0.5 V]. Voltammetric studies were performed using a total of eight working electrodes (i.e. Au, Pt, Ir, Rh, Ag, Cu, Ni, and Co) which were housed in a stainless steel cylinder used at the same time as both the body of the electronic tongue system and the counter/reference electrode. The width of the pulses can also be configured with a maximum value of 40 ms. The system consists of a software application that runs on a PC and electronic equipment. In order to test the capabilities of the designed system, impedometric and voltammetric measurements were carried out on five different commercial cola drinks (brands I–V). Three different waveforms were used in the voltammetric study (i.e. staircase, ascendant SAPV and descendant SAPV). The voltammetric response and the impedance phase and module values obtained were processed using PCA. A remarkable discrimination between all cola drinks was seen using the descendant waveform and a group of metal electrodes (Ni, Co, Cu, Ag). In contrast, impedance spectroscopy technique discriminated one brand (brand I) from the others.     

Experimental tile with phase change materials (PCM) for building use

The use of phase change materials (PCM) and their possible architectural integration is a path in the search for optimizing energy efficiency in construction. As part of this path, a pavement has been designed which, in combination with the PCM, serves as a passive thermal conditioning system (new patent n°. ES2333092 A1) [1]. The prototype has been tested experimentally and the results proved that it is a viable constructive solution improving the energy performance of sunny locals.     

A new algorithm to compute conjectured supply function equilibrium in electricity markets

Several types of market equilibria approaches, such as Cournot, Conjectural Variation (CVE), Supply Function (SFE) or Conjectured Supply Function (CSFE) have been used to model electricity markets for the medium and long term. Among them, CSFE has been proposed as a generalization of the classic Cournot. It computes the equilibrium considering the reaction of the competitors against changes in their strategy, combining several characteristics of both CVE and SFE. Unlike linear SFE approaches, strategies are linearized only at the equilibrium point, using their first-order Taylor approximation. But to solve CSFE, the slope or the intercept of the linear approximations must be given, which has been proved to be very restrictive.This paper proposes a new algorithm to compute CSFE. Unlike previous approaches, the main contribution is that the competitors’ strategies for each generator are initially unknown (both slope and intercept) and endogenously computed by this new iterative algorithm.To show the applicability of the proposed approach, it has been applied to several case examples where its qualitative behavior has been analyzed in detail.     

Microstructure of NiCoAlFeCuCr multi-component systems synthesized by mechanical alloying

The present study uses the mechanical alloying method to produce series of binary to senary alloys based on Ni, Co, Al, Fe, Cu, Cr. Milling times are 0, 10, 20 and 30 h and experiments are performed in a high energy ball mill. The results of this investigation show that an FCC solid solution is formed in all the studied systems, but a different phase formation response is presented in each system. A mixture of FCC and BCC solid solutions in quaternary to senary systems, is formed for short milling times. Apparently, the dissolution rate of Fe and Cr into the FCC solid solution, is low. Moreover, it is observed that additions of these elements promote the formation of BCC solid solution, which is stable at temperatures up to ?1273 K. Finally, it is observed that the heat treated products present a mixture of FCC and BCC solid solutions with lattice parameters close to those found in the milled products.