Yttria-stabilized zirconia as membrane material for electrolytic deoxidation of CaO–CaCl<Subscript>2</Subscript> melts

This article is devoted to the study of the stability of an yttria-stabilized zirconia membrane used in the electrolysis of molten CaCl₂–CaO mixtures at 850 °C. Intensiostatic and potentiostatic electrolysis were carried for periods ranging from 10 to 20 h. Post-mortem composition profiles across the zirconia membrane were determined using Raman spectroscopy and microprobe analysis. The membrane degradation was analyzed in terms of synergetic parameters, i.e., chemical, electrochemical, and thermomechanical effects.     

Isogeometric analysis of the isothermal Navier–Stokes–Korteweg equations

This paper is devoted to the numerical simulation of the Navier–Stokes–Korteweg equations, a phase-field model for water/water-vapor two-phase flows. We develop a numerical formulation based on isogeometric analysis that permits straightforward treatment of the higher-order partial–differential operator that represents capillarity. We introduce a new refinement methodology that desensitizes the numerical solution to the computational mesh and achieves mesh invariant solutions. Finally, we present several numerical examples in two and three dimensions that illustrate the effectiveness and robustness of our approach.     

Phaseolin diversity as a possible strategy to improve the nutritional value of common beans (Phaseolus vulgaris)

This article proposes a new way to improve the protein quality of the common bean (Phaseolus vulgaris). It is based on the natural variability found in the different types of phaseolin, its main storage protein (40–50% of the total protein). Despite the fact that it is deficient in methionine content, phaseolin still represents the main source of that amino acid in the seed. More than 40 genetic variants, differing in subunit number (2–6) and molecular weight (40–54 kDa) have been analyzed. The similarity of the amino acid composition among phaseolins, suggests that a nutritional improvement cannot be expected from that side. Conversely, important variation in phaseolin susceptibility to proteolysis (ranging from 57% to 96% after cooking) has been observed, increasing the theoretical availability of methionine by up to 37%. Therefore, breeding programs based on highly-digestible phaseolin types could lead to the production of beans with higher protein quality.     

The Effective Factors on the Structure of Butter and Other Milk Fat‐Based Products

Butter and other milk fat‐based products are valuable products for the dairy industry due to their unique taste, their textural characteristics, and nutritional value. However, an increased consumer demand for low‐fat‐based products increases the need for an increased essential understanding of the effective factors governing the structure of milk fat‐based products. Today, 2 manufacturing techniques are available: the churning method and the emulsification method. The first is typically used for production of butter with a globular structure, which has become increasingly popular to obtain low‐fat‐based products, typically without presence of milk fat globules. The microstructure of milk fat‐based products is strongly related to their structural rheology, hence applications. Structural behavior is not determined by one single parameter, but by the interactions between many. This complexity is reviewed here. Parameters such as thermal treatment of cream prior to butter making, water content, and chemical composition influence not only crystal polymorphism, but also the number and sizes of fat crystals. The number of crystal–crystal interactions formed within the products is related to product hardness. During storage, however, postcrystallization increases the solid fat content and strengthens the fat crystal network. The fat crystal network is strengthened by the formation of more and stronger crystal–crystal interactions due to mechanically interlinking of fat crystals, which occurs during crystal growth. Postcrystallization is directly linked to chemical composition. The initially observed microstructural difference causing different rheological behavior will disappear during storage due to postcrystallization and formation of more crystal–crystal interactions.     

On generalized communicating P systems with minimal interaction rules

Generalized communicating P systems are purely communicating tissue-like membrane systems with communication rules which allow the movement of only pairs of objects. In this paper, we study the power of these systems in the case of eight restricted variants of communication rules. We show that seven of these restrictions lead to computational completeness, while using the remaining one the systems are able to compute only finite singletons of non-negative integers. The obtained results complete the investigations of the computational power of generalized communicating P systems and provide further examples for simple architectures with simple functioning rules which are as powerful as Turing machines.     

Experimental behaviour of the reverse channel joint component at elevated and ambient temperatures

The reverse channel connection appears to have the best combination of desirable features under fire loading: moderate construction cost, ability to develop catenary action and extremely high ductility through deformation of the web channel (Ding and Wang, 2007). This paper presents the results of an experimental investigation of a reverse channel component conducted at the University of Coimbra as part of the European RFCS COMPFIRE Project, the main focus of which is to characterise the behaviour of steel joints that connect steel beams to concrete-filled tubular columns under natural fire loading. A series of tensile and compressive tests at ambient and elevated temperatures was conducted. The purposes of the experimental tests were to characterise the strength, stiffness and ductility of this joint component and to establish a relationship between force, displacement and temperature.     

Defect-Related Physical-Profile-Based X-Ray and Neutron Line Profile Analysis

Diffraction line broadening is caused by different defects present in crystalline materials: (1) small coherent domains, (2) dislocations, (3) other types of microstrains, (4) twin boundaries, (5) stacking faults, (6) chemical inhomogeneities, and (7) grain-to-grain second-order internal stresses. Line profile analysis provides qualitative and quantitative information about defect types and densities, respectively. Line profiles can broaden, be asymmetric, and be shifted, and these features can be anisotropic in terms of hkl indices. A few thumb rules help qualitative selection of lattice defect types. If the breadths do not increase globally with hkl, the defects are of size type, i.e., either the domain size is small or twinning or faulting, or both, is present. Whenever the breadths increase globally, the defects produce microstrains. Physically based profile functions can be determined for the different defect types and hkl anisotropy. The qualitative input about defect types based on different experimental observations allows adequate quantitative evaluation of the densities of different defect types by using physically modeled profile functions.     

Influence of the final ethanol concentration on the acetification and production rate in the wine vinegar process

BACKGROUND: The acetification process needs an overall study of the variables influencing it in order to establish their optimum values. Based on industrial experience and available literature, including a recently proposed model by the authors, among the variables most strongly influencing the acetification process are the ethanol concentration at the time the reactor is unloaded, the unloaded volume and the loading rate. To ensure economically efficient industrial production of vinegar, and to check the predictions of the aforementioned model, the influence of the final ethanol concentration at unloading time on the mean acetification rate and on productivity has been studied in this work. RESULTS: An increase in the final ethanol concentration from 0.5 to 3.5% (v/v) increased the mean overall acetification rate and acetic acid production by 38 and 26%, respectively. The increase was established mainly during the loading phase. CONCLUSIONS: The final ethanol concentration is a key variable for process optimization. If a high rate is desired then a product containing much unused substrate will be obtained, which may be industrially unacceptable. These results suggest the necessity to investigate other possibilities when high values for yield and productivity must to be achieved. Copyright © 2010 Society of Chemical Industry     

SEM study of the morphology of asymmetric cellulose acetate membranes produced from recycled agro-industrial residues: sugarcane bagasse and mango seeds

Cellulose, obtained both from sugarcane bagasse and mango seeds, was used for synthesizing cellulose acetate in order to produce asymmetric membranes. These were compared to membranes of commercial cellulose acetate (Rhodia). All produced membranes were asymmetric, characterized by the presence of a dense skin and a porous support. Differences regarding the morphology of the surfaces as well as of the porous support can be noticed. Scanning Electron Microscopy (SEM) showed that the morphology of the superficial layer, responsible for transport, depends on the different lignin content of the starting material and also on the viscosity average molecular weight of the cellulose acetates produced from sugarcane bagasse, mango seed, and Rhodia’s commercial cellulose acetate.