Development of the Multidimensional Acculturative Stress Inventory for adults of Mexican origin.

The Multidimensional Acculturative Stress Inventory (MASI), a 36-item stress measure that was developed to assess acculturative stress among persons of Mexican origin living in the United States, was tested on a community sample of 174 adults (117 women, 57 men). Principal-components analyses yielded 4 stable and internally consistent factors: Spanish Competency Pressures (7 items), English Competency Pressures (7 items), Pressure to Acculturate (7 items), and Pressure Against Acculturation (4 items). These 4 factors accounted for 64.4% of the variance and correlated in the expected directions with criterion measures of acculturation and/or psychological adjustment. Further reliability and validity testing of the MASI is discussed as well as the utility of this measure in assessing acculturative stress among adults of Mexican origin. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A combined measure for quantifying and qualifying the topology preservation of growing self-organizing maps

The Self-Organizing Map (SOM) is a neural network model that performs an ordered projection of a high dimensional input space in a low-dimensional topological structure. The process in which such mapping is formed is defined by the SOM algorithm, which is a competitive, unsupervised and nonparametric method, since it does not make any assumption about the input data distribution. The feature maps provided by this algorithm have been successfully applied for vector quantization, clustering and high dimensional data visualization processes. However, the initialization of the network topology and the selection of the SOM training parameters are two difficult tasks caused by the unknown distribution of the input signals. A misconfiguration of these parameters can generate a feature map of low-quality, so it is necessary to have some measure of the degree of adaptation of the SOM network to the input data model. The topology preservation is the most common concept used to implement this measure. Several qualitative and quantitative methods have been proposed for measuring the degree of SOM topology preservation, particularly using Kohonen's model. In this work, two methods for measuring the topology preservation of the Growing Cell Structures (GCSs) model are proposed: the topographic function and the topology preserving map.     

Highly efficient multi-metal catalysts for carbon dioxide reduction prepared from atomically sequenced metal organic frameworks

The precise control on the combination of multiple metal atoms in the structure of metal-organic frameworks(MOFs)endowed by reticular chemistry,allows the obtaining of materials with compositions that are programmed for achieving enhanced reactivity.The present work illustrates how through the transformation of MOFs with desired arrangements of metal cations,multi-metal spinel oxides with precise compositions can be obtained,and used as catalyst precursor for the reverse water-gas shift reaction.The differences in the spinel initial composition and structure,determined by neutron powder diffraction,influence the overall catalytic activity with changes in the process of in s itu formation of active,metal-oxide supported metal nanoparticles,which have been monitored and characterized with in situ X-ray diffraction and photoelectron spectroscopy studies.     

Decomposition of nitrous oxide in excess oxygen over Co- and Cu-exchanged MFI zeolites

The decomposition of nitrous oxide on several Co- and Cu-ZSM-5 zeolite catalysts was studied in the absence and presence of excess oxygen. Also, the effect of methane addition, as well as catalyst steaming in dry and wet feeds is reported. N₂O decomposition with no oxygen in the feed was proportional to metal loading on both catalysts. Co-ZSM-5 was much more resistant than Cu-ZSM-5 in excess oxygen. The tolerance of Co-ZSM-5 catalysts to excessive amounts of oxygen is high when Co²⁺ is stabilized in the zeolite framework and depends on the catalyst method of preparation. The presence of methane with no oxygen in the feed enhanced N₂O decomposition while the addition of both methane and oxygen to the feed decreased N₂O conversion on all catalysts tested. Co²⁺ ions stabilized by ZSM-5 framework have high hydrothermal stability in comparison to Cu²⁺ -exchanged ZSM-5.     

Local optimal scale in a hierarchical segmentation method for satellite images

Over recent decades, remote sensing has emerged as an effective tool for improving agriculture productivity. In particular, many works have dealt with the problem of identifying characteristics or phenomena of crops and orchards on different scales using remote sensed images. Since the natural processes are scale dependent and most of them are hierarchically structured, the determination of optimal study scales is mandatory in understanding these processes and their interactions. The concept of multi-scale/multi-resolution inherent to OBIA methodologies allows the scale problem to be dealt with. But for that multi-scale and hierarchical segmentation algorithms are required. The question that remains unsolved is to determine the suitable scale segmentation that allows different objects and phenomena to be characterized in a single image. In this work, an adaptation of the Simple Linear Iterative Clustering (SLIC) algorithm to perform a multi-scale hierarchical segmentation of satellite images is proposed. The selection of the optimal multi-scale segmentation for different regions of the image is carried out by evaluating the intra-variability and inter-heterogeneity of the regions obtained on each scale with respect to the parent-regions defined by the coarsest scale. To achieve this goal, an objective function, that combines weighted variance and the global Moran index, has been used. Two different kinds of experiment have been carried out, generating the number of regions on each scale through linear and dyadic approaches. This methodology has allowed, on the one hand, the detection of objects on different scales and, on the other hand, to represent them all in a single image. Altogether, the procedure provides the user with a better comprehension of the land cover, the objects on it and the phenomena occurring.     

Life cycle assessment of a ceramic glaze containing copper slags and its application on ceramic tile

Even though copper slags have many possible applications, their disposal is still practiced, creating long-term waste management problems. This led to the investigation of new products for residential applications, taking advantages of the interesting chemical properties of copper slag. This study aims to assess the environmental impact of the use of copper slag as secondary raw material in a ceramic glaze composition and to compare it with a traditional glaze. A manufacturing process was designed, through an industrial scale up operation from experimental laboratory data and the entire life cycle of the products was analyzed using the Life-cycle assessment (LCA) methodology. Considering the production of a ceramic glaze containing copper slag, the most impacting process resulted the one related to frit production, due to the large amount of thermal energy necessary for the raw materials melting. The comparative LCA analysis carried out between the frit obtained from metallurgical slags and a traditional one, demonstrated that the innovative ceramic frit has a greater environmental advantage. The LCA analysis allowed to highlight the most impactful stages of an industrial process using copper slag as a secondary raw material for glaze production and to quantify the potential environmental advantages of this operation.     

Opportune inward waste materials toward a zero waste ceramic slabs production in a circular economy perspective

This work is related to the preliminary lab-scale preparation of ceramic slabs, reproducing the characteristics of natural stones, containing up to more than 40 wt.% of different waste materials, namely laboratory glass, cullet glass (both thought as fluxing agents replacing feldspar), and ceramic waste obtained from drying squaring operations (for partial quartz sand replacement). Indeed, in order to pursue the circular economy principles, the possibility of turning different kinds of wastes into resources for the ceramic industry, surely represents the first concern to be addressed and demonstrated, with also the aim to reduce the environmental impact associated with landfill, minimizing manufacturing cost and contributing to preserve nonrenewable natural resources, which are known to be consistently depleted by the ceramic industries.     

Effect of the pyrolysis atmosphere on the mechanical properties of polymer-derived SiOC and SiCN

Mechanical properties of polymer-derived ceramics are usually measured on samples pyrolyzed in inert atmosphere. Here, we report the hardness and elastic modulus of SiOC and SiCN pyrolyzed in both inert (Ar) and reactive (CO₂) atmosphere. The external surface of the specimens exposed to the pyrolysis gas was characterized by Vickers microhardness measurements and infrared spectroscopy. The elastic modulus was evaluated by three-point bending tests on thin (150-200 µm) and dense specimens. Polished sections of the SiOC samples were prepared to study, by energy-dispersive X-ray spectroscopy (EDXS) and nanoindentation, how the elemental composition, hardness, and elastic modulus vary from the surface toward the bulk. For both compositions, pyrolysis in CO₂ leads to a strong decrease in the hardness and elastic modulus. The hardness of both the samples pyrolyzed in CO₂ approaches the typical value for fused silica, suggesting that CO₂ selectively breaks the Si–C and Si–N bonds and leads to the formation of a silica-like network. EDXS and nanoindentation reveal that the modification induced by the CO₂ flow extends below the surface at least for a thickness of about 30 µm.     

Optimization of Reaction Conditions in the Enzymatic Interesterification of Soybean Oil and Fully Hydrogenated Soybean Oil to Produce Plastic Fats

Semisolid fats obtained from oils and fats through enzymatic interesterification have interesting applications. The effect of certain reaction parameters (enzyme concentration, moisture content, reaction time, substrate ratio, temperature, and agitation level) over the enzymatic interesterification of fully hydrogenated soybean oil (FHSO) and refined soybean oil (SO) using two immobilized enzyme types (Lipozyme RM IM and Lipozyme TL IM), was studied with a fractional factorial design (FFD). The reaction products were analyzed with respect to melting point (mp), by-products content and triacylglycerols (TAG) composition. It was found that substrate ratio, reaction time, and their interaction presented the most significant contributions to mp, varying this from 43.4 to 61.5 °C. The highest contributions to by-product content were presented by time and its interaction with the amount of molecular sieves, mainly for Lipozyme TL IM. Through the models obtained, theoretical conditions to achieve minimal by-product generation and mp were found, being 5.0 % (w/w_subst.) of any of both lipases, 24 h, 70:30 (oil:fat,  % w/w), 65 °C, 230 rpm, and absence of molecular sieves. Regression models for TAG groups as a function of significant factors and interactions were constructed, offering useful information to establish the reaction conditions for obtaining a product with a target mp or chemical composition.     

Evaluation of the effect of drying on aroma of parsley by free choice profiling

Parsley has wide culinary usage in Spain and as a result of its characteristic colour, aroma and flavour is used in preparing food and drink to enhance taste and appearance. The effect of different drying treatments on the aroma characteristics of parsley (Petroselinum crispum L.) was studied using free choice profiling (FCP) analysis. Differences between samples were observed after applying generalised Procrustes analysis (GPA) to the FCP data. The highest differences were found between fresh parsley samples and dried samples obtained by air-drying at ambient temperature, oven-drying at 45 ºC and freeze-drying. However, air-drying at ambient temperature produced less changes in aroma characteristics than the other drying methods and preserved the fresh and herbaceous notes.