Assessment of Postharvest Dehydration Kinetics and Skin Mechanical Properties of “Muscat of Alexandria” Grapes by Response Surface Methodology

The dipping of berries in a dilute solution of sodium hydroxide during a short time was evaluated as pretreatment undertaken prior to convective dehydration of wine grapes. The impact of the sodium hydroxide content and dipping time on weight loss (WL) at different dehydration times was thoroughly assessed using central composite design (CCD) and response surface methodology (RSM). Furthermore, the effects of these two variables were also investigated on the skin mechanical properties of dehydrated grapes. The effect of these two pretreatment factors on the dehydration kinetics and skin hardness was satisfactorily fitted to regression models. The berry pretreatment with low sodium hydroxide contents (from 10 to 20 g/L) facilitated the dehydration process during the first 5 days when dipping times longer than 300 s were used. From the seventh day of dehydration, at which time the average WL% was close to 50, the highest values of WL% were obtained using intermediate sodium hydroxide contents and dipping times (around 45 g/L and 185 s, respectively). Because skin hardness affects the dehydration kinetics during postharvest withering, the strongest decrease in skin hardness corresponded to these last berry pretreatment conditions, whereas the greatest increase required the highest sodium hydroxide contents and longest dipping times. The quality of berries dehydrated may be influenced by the pretreatment conditions used, and the present study contributes to increase the knowledge on this effect to a better management of the alkaline pretreatment and dehydration process.     

Filtration Efficiency of Functionalized Ceramic Foam Filters for Aluminum Melt Filtration

Metallurgical and Materials Transactions B - The influence of filter surface chemistry on the filtration efficiency of cast aluminum alloys was evaluated for four different filter coating...     

Neoantigen-Specific T-Cell Immune Responses: The Paradigm of NPM1-Mutated Acute Myeloid Leukemia

The C-terminal aminoacidic sequence from NPM1-mutated protein, absent in normal human tissues, may serve as a leukemia-specific antigen and can be considered an ideal target for NPM1-mutated acute myeloid leukemia (AML) immunotherapy. Different in silico instruments and in vitro/ex vivo immunological platforms have identified the most immunogenic epitopes from NPM1-mutated protein. Spontaneous development of endogenous NPM1-mutated-specific cytotoxic T cells has been observed in patients, potentially contributing to remission maintenance and prolonged survival. Genetically engineered T cells, namely CAR-T or TCR-transduced T cells, directed against NPM1-mutated peptides bound to HLA could prospectively represent a promising therapeutic approach. Although either adoptive or vaccine-based immunotherapies are unlikely to be highly effective in patients with full-blown leukemia, these strategies, potentially in combination with immune-checkpoint inhibitors, could be promising in maintaining remission or preemptively eradicating persistent measurable residual disease, mainly in patients ineligible for allogeneic hematopoietic stem cell transplant (HSCT). Alternatively, neoantigen-specific donor lymphocyte infusion derived from healthy donors and targeting NPM1-mutated protein to selectively elicit graft-versus-leukemia effect may represent an attractive option in subjects experiencing post-HSCT relapse. Future studies are warranted to further investigate dynamics of NPM1-mutated-specific immunity and explore whether novel individualized immunotherapies may have potential clinical utility in NPM1-mutated AML patients.     

Characterization of fatigue resistance in photochromic composite materials for 3D rewritable optical memory applications

Fatigue resistance of the photochromic diarylethene molecules 1,2-bis[2-methylbenzo[b]thyophen-3-yl]-3,3,4,4,5,5-hexafluoro-1-cyclopentene embedded in three different acrylic polymers is studied upon multiple coloration–decoloration cycles. The resistance to photofatigue is found to be different in the three polymeric materials when one-photon excitation was used for the reversible photoconversion experiment. In particular, the photochromic molecules lose their photoisomerization ability faster if they are embedded in poly(methyl methacrylate) (PMMA) with respect to poly(ethyl methacrylate-co-methyl acrylate) (PEMMA) and poly(ethyl methacrylate) (PEMA). We propose several explanations based on the physico-chemical properties of the matrix and of the photochromic molecules. In the case of two-photon excitation, which is necessary for 3D optical writing, the fatigue resistance is found to be poorer than in the one-photon case. The accelerated photodegradation can be assigned to the non-linear nature of interaction between the polymeric composite material and light.     

Sensing,smart and sustainable product development (S3 product) reference framework

Enterprises must become ‘sensing, smart and sustainable (S³)’ to face global challenges related to local, national and global market dynamics. Therefore, reconceptualisation and redesign in these enterprises must accommodate emergent technologies, new practices and strategies. In this sense, enterprises have used new product development as a strategy for remaining competitive in the marketplace; thus, they can provide a new generation of products offering solutions to contemporary social problems and responding to changing consumer demands. These new-generation products are mostly technology-based and consider sustainable objectives. In this context, concepts such as sensing, smart and sustainable products (S³ products) have emerged to satisfy different social requirements. Therefore, this work focuses on providing a reference framework that presents a systematic process for the development of S³ products. This reference framework is based on the integrated product, process and manufacturing system development reference model. The main objective of this work is to fill the gap vis-à-vis the current lack of design roadmaps that permit the development of this new generation of products in S³ enterprises. The development of a reconfigurable micro-machine tool is presented as that of an S³ product.     

Electronic Structure and Half-Metallic Character in Sr2CoB′O6 (B′ = Mo, Re) Materials

We report several ab initio calculations performed for Sr₂CoB′O₆ (B′ = Mo, Re) by means of the Density Functional Theory and the Linearized Augmented Plane Waves method with spin polarization. For the calculations, the exchange and correlation potentials were included through the local density LDA+U approximation with B3PW91. Density of states (DOS) study was carried out considering both up and down spin polarizations by the Generalized Gradient Approximation (GGA). From the Murnaghan state equation, we calculate the cell dimensions that minimize the total energy. Our results of DOS calculations show that the Sr₂CoMoO₆ material presents a metallic behavior, while Sr₂CoReO₆ reveals a half-metallic nature with conductor behavior for the spin down orientation and semiconducting feature for spin up channel. It was observed close to Fermi level that the low-energy spin down states of Co are responsible by the majority contribution to conduction band. The calculated effective cell magnetic moment of the Sr₂CoReO₆ compound evidences a value 2.02 μ _B , which is close to an integer number as expected for a half-metallic material.     

Multi-tube Pd–Ag membrane module for pure hydrogen production: Comparison of methane steam and oxidative reforming

The results of steam and oxidative reforming of methane carried out through a membrane system are being compared in this work. The capability of the experimental setup to produce ultra-pure hydrogen has been evaluated in terms of hydrogen yield under different operating conditions.     

Mixed-dimensional elements in transient thermal analysis of gradient coils

ABSTRACT

This article proposes a numerical formulation for handling mixed-dimensional elements embedded in a standard three-dimensional (3d) mesh, avoiding thus the volume meshing of filaments and strips. The method is then applied to predict the temperature heating and cooling profile of gradient coils in magnetic resonance imaging. These coils are typically constructed from copper wires or tracks and embedded in an epoxy layer. It was found that the new method significantly reduces the computational time of steady-state and transient simulations, with speedups in the range of 3.5-5. The method proved to be accurate, with relative errors below 0.5% for steady-state simulations and 1.5% with respect to a complete 3d simulation.     

Mathematical Modeling of Fluid Flow in a Water Physical Model of an Aluminum Degassing Ladle Equipped with an Impeller-Injector

In this work, a 3D numerical simulation using a Euler–Euler-based model implemented into a commercial CFD code was used to simulate fluid flow and turbulence structure in a water physical model of an aluminum ladle equipped with an impeller for degassing treatment. The effect of critical process parameters such as rotor speed, gas flow rate, and the point of gas injection (conventional injection through the shaft vs a novel injection through the bottom of the ladle) on the fluid flow and vortex formation was analyzed with this model. The commercial CFD code PHOENICS 3.4 was used to solve all conservation equations governing the process for this two-phase fluid flow system. The mathematical model was reasonably well validated against experimentally measured liquid velocity and vortex sizes in a water physical model built specifically for this investigation. From the results, it was concluded that the angular speed of the impeller is the most important parameter in promoting better stirred baths and creating smaller and better distributed bubbles in the liquid. The pumping effect of the impeller is increased as the impeller rotation speed increases. Gas flow rate is detrimental to bath stirring and diminishes the pumping effect of the impeller. Finally, although the injection point was the least significant variable, it was found that the “novel” injection improves stirring in the ladle.     

Effect of Al2O3 reinforcement and precipitates on corrosion behaviour of 2618 and 6061 aluminium MMCs

ABSTRACT

The corrosion resistance features of two different Metal Matrix Composites based on 6061 and 2618 aluminium alloys reinforced by 20% Al₂O₃ particles by stir casting process, were studied in 3.5% NaCl and compared. The composites and their respective base alloys were characterised in terms of microstructure by optical and scanning electron microscopy and in terms of corrosion resistance by polarisation curves and electrochemical impedance. Results show how the presence of Al₂O₃ has different effects depending on matrix composition. In 6061 MMC, Al₂O₃ promotes the formation of Mg₂Si which has a cathodic behaviour altering the pitting susceptibility of the composite. In 2618 MMC, the high content of Cu induces a strong uniform attack. The subsequent increase in the Open Circuit Potential caused a pitting attack.