Influence of the chemical structure of additives poly(ethylene-co-vinyl acetate)-based on the pour point of crude oils

One of the methods to prevent wax precipitation, during petroleum production, transport, and refining, is the use of polymer additives that can reduce the oil pour point. However, no single additive work for all types of crude oil and this relation is not yet well known. In this study, a family of polymers based on poly(ethylene-co-vinyl acetate), containing hydroxyl groups and long pendant hydrocarbon chains (from C6 to C18), were synthesized and characterized by H¹ nuclear magnetic resonance and solubility test. Four crude oil samples containing different amounts and size distribution of the wax were used. The additive's action is favored by higher contents of iso + cycloalkanes and lower contents of n-paraffins with larger chain sizes. The presence of the CH₃COO group in the copolymers promoted the lowering of the pour point, supported by a low OH concentration and the presence of a long pendant hydrocarbon chain: the best results were obtained with C10 and C12 chain lengths. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48969.     

Protective effect of estrogens and catecholestrogens against peroxidative membrane damagein vitro

The antioxidant effects of natural estrogens (estrone E₁; 17β-estradiol), synthetic estrogens (17α-ethynylestradiol, EE₂; mestranol, MES; diethylstilbestrol, DES) and catechle-strogens (2-hydroxyestradiol; 4-hydroxyestradiol 4-OHE₂) on lipid peroxidation induced by different means in rat liver microsomes were investigated. The extent of lipid peroxidation was determined by measuring thiobarbituric acid reactive substances. Prooxidants included Fe³⁺/ADP/reduced NADPH, Fe²⁺/ascorbate,tert-butyl hydroperoxide (t-BOOH) and 2,2′-azobis (2-amidinopropane) (AAPH). Estrogens and catecholestrogens decreased lipid peroxidation in all four systems tested. In the iron/ascorbate model it was shown that (i)-OHE₂ and DES had analogous patterns of inhibition, irrespective of the presence of NADPH or the functional integrity of the microsómes, and (ii) the antioxidant activities of E₁, EE₂ and MES were dependent on the assay conditions with the activity being markedley higher when estrogen metabolism was favored. When peroxidation was initiated by the peroxyl radical generator AAPH, the inhibitory effects observed were least pronounced. Our data also showed that, in each of the systems, all inhibitors displayed the same order of inhibitory potency with DES and catecholestrogens being the most potent antioxidants under all experimental conditions used. The present results confirm earlier findings and point toward a link between estrogen metabolism and estrogen antioxidant activity. The data also indicate that estrogens and catecholestrogens interact with the peroxidative process at different levels with their interactions with iron or the metal-derived species being the most important modes of inhibition.     

Feasibility study of the cut and weld operations by RH on the cooling pipes of ITER NB components

The maintenance operations of ITER NB components inside the vessel - Beam Line Components (BLC's) involve the removal of the faulty component, its transport to the hot cell as well as the reverse operations of transport of the repaired/new component and its reinstallation inside the vessel. Prior to the removal of the BLC's the cooling pipes must be detached from the component following a procedure that applies to the cutting of the pipes and subsequent welding when the component is re-installed. The purpose of this study, conducted in the framework of EFDA, is to demonstrate the feasibility of the cut and weld operations on the water pipes of the BLC's using fully remote handling techniques. Viable technologies for the cut and weld operations have been identified within the study; in particular the following aspects will be presented in the paper:

• Different strategies can be pursued in the detachment of the components depending on the number of cut and weld operations to be performed on the pipes. The selected strategy will impact on the procedure to be followed likewise on important aspects as the requirements of the flexible joints assembled on the pipes.

• The existing cutting techniques have been examined in the light of the remotely performed pipe cutting at the NB cell. Modifications of commercial tools have been proposed in order to adapt them to the BLC's pipes requirements. The debris produced during the cutting process must be controlled and collected, therefore a cleaning system has been integrated in the adapted cutting tool referred above.

• The existing welding techniques have been also examined and compared based on different criteria such as complexity, reliability, alignment tolerances, etc. TIG welding is the preferred technique as it stands out for its superior performance. The commercial tools identified need to be adapted to the NB environment.

• The alignment of the pipes is a critical issue concerning the remote welding. A proper alignment system has been proposed taking into account the pre-selected welding technique.

Mineral profile of “fino” wines using inductively coupled plasma optical emission spectrometry methods

Fifty wines from the Denomination of origin (DO) of Condado de Huelva were analysed for mineral content by measuring 12 elements (Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, P, Sr and Zn) using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Samples were previously digested by heating with H₂O₂/HNO₃ mixture. The results obtained showed that metal data set were non-normally distributed and accordingly, non-parametric statistics were applied. The average levels (medians) of these elements found in the samples are as follows, in mg/L: 2.54 (Al); 0.06 (Ba); 82.58 (Ca); 0.21 (Cu); 3.53 (Fe); 865.34 (K); 68.87 (Mg); 0.71 (Mn); 32.77 (Na); 71.61 (P); 0.48 (Sr); 0.56 (Zn). The interrelation of metal couples was studied through the Spearman non-parametric sample correlation, being Fe/Al, P/Mg, and Zn/Ba the most important correlations established. As a result of this study, we can suggest that the contribution to the safety intake limits (per week) of the studied elements through the wine consumption is not significant. Actually, they range between 0.1% in Fe and 11.9% in Mg, for normal drinkers.     

Influence of phosphorylated rice flour on the quality of gluten‐free bread

The chemical modification of rice flour by phosphorylation is an alternative to improve the technological quality of bakery products. The aim of this study was to investigate the effect of phosphorylation process of rice flour on technological properties (specific volume, crumb and crust colour) of gluten‐free breads and the hardening of these breads during two storage temperatures (21 °C and ?24 °C). Breads were made with native rice flour, with phosphorylated rice flour and with wheat flour, used as control. The phosphorylation causes significant reduction in the synaeresis of pastes and in retrogradation tendency of rice flours, varying from 258.7 cP (native rice flour) to 122 cP (phosphorylated rice flour). The breads prepared with phosphorylated rice flour showed reduction in the hardness in both storage temperatures studied and effect on rice bread volume, crumb appearance and colour, demonstrating the possibility of use of the phosphorylated rice flour in gluten‐free breads.     

Assessing performance of skim milk ultrafiltration by using technical parameters

In the present study a mathematical model has been applied to interpret the permeate flux decay that occurs during the process of concentrating skim milk by ultrafiltration using a commercial membrane module. The effects on membrane fouling of two operational variables, temperature and transmembrane pressure, have been studied using technical parameters. An energy analysis has demonstrated that the major energy consumption takes place in the thermal process and not in the mechanical pumping of the fluid. In addition, higher increments in permeate volume can be achieved by increasing transmembrane pressure, not temperature. The mathematical analysis presented here permits the evaluation of optimum values of the engineering parameters necessary to design and operate skim milk ultrafiltration units.     

Raman analysis of surimi gelation by addition of wheat dietary fibre

Raman analysis has been carried out to study the effects of Vitacel^® wheat dietary fibre (WDF) during gelation of surimi. The main results reveal the following: (a) Vitacel^® comprises natural cellulose I as major component; (b) hydration of WDF leads to νCH frequency upshifting and decreasing intensity. On the basis of these spectral features it is suggested that water transfer from protein to WDF can occur in surimi gels. WDF hydration can be interpreted in the sense that this fibre either takes water that is delivered from the gel protein upon heat-mediated formation of β-sheets and hydrophobic contacts and/or or acts as an active dehydrating agent. An increase of solvent-exposed hydrophobic side chains is observed in the sol phase, upon the addition of WDF, which may cause breaking of intermolecular protein hydrophobic contacts; a subsequent change upon WDF-containing gel formation is the reduction in the νCH intensity, which may be indicative of increasing hydrophobic WDF-protein contacts. Interestingly, these results constitute molecular data, to be considered when designing restructured fish products with these fibre ingredients.     

Ultrasonic techniques for quality assessment of ITER Divertor plasma facing component

The divertor is one of the most challenging components of ITER machine. Its plasma facing components contain thousands of joints that should be assessed to demonstrate their integrity during the required lifetime. Ultrasonic (US) techniques have been developed to study the capability of defect detection and to control the quality and degradation of these interfaces after the manufacturing process. Three types of joints made of carbon fibre composite to copper alloy, tungsten to copper alloy, and copper-to-copper alloy with two types of configurations have been studied. More than 100 samples representing these configurations and containing implanted flaws of different sizes have been examined.US techniques developed are detailed and results of validation samples examination before and after high heat flux (HHF) tests are presented. The results show that for W monoblocks the US technique is able to detect, locate and size the degradations in the two sample joints; for CFC monoblocks, the US technique is also able to detect, locate and size the calibrated defects in the two joints before the HHF, however after the HHF test the technique is not able to reliably detect defects in the CFC/Cu joint; finally, for the W flat tiles the US technique is able to detect, locate and size the calibrated defects in the two joints before HHF test, nevertheless defect location and sizing are more difficult after the HHF test.     

Finite element simulation to design constructive elements: An application to light gypsum plaster for partitions

In the past decade finite element simulation has become a very useful methodological tool in the different science fields. This article offers a specific application of this powerful mechanism used for analyzing the mechanical behaviour of constructive elements in the design phase, prior to the laboratory tests’ stage. The aim of applying this simulation is to minimize the high cost the real scale fabrication of these elements entails.This research focuses on the analysis by finite element simulations (FES) of several construction elements used as interior partitions and made of plaster lightened with cork. The results of the study will allow us to determine the most suitable thickness values and proportions to ensure that the requirements stated by the standards and norms for light partitions are fulfilled. These parameters will later be useful for the final laboratory tests.Two simulation groups have been developed using the ANSYS application: firstly, a partition leaf of 200 × 260 cm is studied exposing it to a superficial load and to an eccentric load following the EUAtc common directives for the technical appreciation of light panels, 1973). Second, the behaviour of a panel with a through opening is tested with the simulation regarding the different hypothesis of the structure deformation supporting and surrounding it.Finally, it is proved that the element of thickness 7 cm and proportions stated at the beginning ensure a good performance regarding strain without producing any visible fissures, and therefore are suitable for a further laboratory test on real models.