Anisotropy of turbulence in wind turbine wakes

This work is mainly dedicated to the study of non-isotropic characteristics of turbulence in wind turbine wakes, specifically the shear layer of the near wake. A calculation method based on an explicit algebraic model for the components of the turbulent stress tensor is proposed, and the results are found to be in acceptable agreement with experimental results. Analytical expressions for the estimation of an upper limit of the global turbulence kinetic energy, k, and the individual contributions of each diagonal term in the turbulent stress tensor are proposed. Their predictions are compared with experimental results.     

Palladium metal nanoparticles on organically modified thin hybrid films

Hybrid thin films containing palladium nanoparticles in different concentrations (0.5% and 1%) with and without nanoparticle stabiliser agent [mercaptopropyl trimethoxysilane, MPTMS] were prepared using a sol–gel process. Pd nanoparticles were found to be highly dispersed on the thin films with particles ranging from 7 to 10 nm. The catalytic properties of the thin films supported Pd nanoparticles were investigated in the Heck reaction of iodobenzene and methyl acrylate. Films containing Pd MNP (with and without MPTMS) gave quantitative conversion and complete selectivity to the targeted product (methyl cinnamate) in a short time of reaction (<15 min) under microwave irradiation. While Pd containing films without MPTMS were highly active and reusable after 3 runs, MPTMS containing films were found to be inactive after the first use. Such phenomenon was correlated to the steric hindrance round the Pd MNP due to the adsorption of species on the surface that render the catalysts inactive.     

Galacto‐Oligosaccharides: Production,Properties, Applications,and Significance as Prebiotics

Abstract: Galacto‐oligosaccharides (GOS) have now been definitely established as prebiotic ingredients after in vitro and animal and human in vivo studies. Currently, GOS are produced by glycoside hydrolases (GH) using lactose as substrate. Converting lactose into GOS by GH results in mixtures containing GOS of different degrees of polymerization (DP), unreacted lactose, and monomeric sugars (glucose and galactose). Recent and future developments in the production of GOS aim at delivering purer and more efficient mixtures. To produce high‐GOS‐content mixtures, GH should not only have good ability to catalyze the transgalactosylation reaction relative to hydrolysis, but also have low affinity for the GOS formed relative to the affinity for lactose. In this article, several microbial GH, proposed for the synthesis of GOS, are hierarchized according to the referred performance indicators. In addition, strategies for process improvement are discussed. Besides the differences in purity of GOS mixtures, differences in the position of the glycosidic linkages occur, because different enzymes have different regiochemical selectivity. Depending on oligosaccharide composition, GOS products will vary in terms of prebiotic activity, as well as other physiological effects. This review focuses on GOS production from synthesis to purification processes. Physicochemical characteristics, physiological effects, and applications of these prebiotic ingredients are summarized. Regulatory aspects of GOS‐containing food products are also highlighted with emphasis on the current process of health claims evaluation in Europe.     

The Potential of Proteins for Producing Food Packaging Materials: A Review

The problems associated with obtaining conventional plastic materials and with their accumulation have led to a constant search for new materials derived from renewable sources. Materials made from proteins stand out among them all because of the many ways in which they can be modified enzymatically, chemically or physically, giving rise to materials with improved physicochemical properties that are adjustable to each specific application. This paper reviews the state of the art with regard to the use of proteins for the manufacture of packaging materials, including: the main protein sources that have been used; manufacturing methods (coating on conventional materials, thermoforming, extrusion), with special emphasis on materials made by extrusion; possible strategies for improving the physicochemical properties of the materials and the main future prospects and limitations of materials of this kind.     

Ziprasidone: Pharmacological and clinical profile of the newest atypical antipsychotic.

Notes that ziprasidone is the 5th atypical antipsychotic to be approved by the Food and Drug Administration for the treatment of schizophrenia. Since 1989, when the first atypical agent was introduced to the US market, clinical use of these compounds has progressed to the point that several atypical agents are considered first-line treatment for schizophrenia. This article reviews pharmacological and clinical aspects of ziprasidone to familiarize clinicians who will encounter its use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wave climate off the Swedish west coast

This paper presents and discusses the wave climate off the Swedish west coast. It is based on 8 years (1997–2004) of wave data from 13 sites, nearshore and offshore, in the Skagerrak and Kattegat. The data is a product of the WAM and SWAN wave models calibrated at one site by a wave measurement buoy. It is found that the average energy flux is approximately 5.2 kW/m in the offshore Skagerrak, 2.8 kW/m in the nearshore Skagerrak, and 2.4 kW/m in the Kattegat. One of the studied sites, i.e. site 9, is the location of a wave energy research site run by the Centre for Renewable Electric Energy Conversion at Uppsala University. This site has had a wave power plant installed since the spring of 2006, and another seven are planned to be installed during 2008. Wave energy as a renewable energy source was the driving interest that led to this study and the results are briefly discussed from this perspective.     

Amino acids evolution during ripening of goats' milk cheese manufactured with different coagulants

Powdered plant coagulant obtained from the cardoon flowers ( Cynara cardunculus ) was compared with calf rennet for the manufacture of traditional raw goats' milk cheese, by determining differences in the profiles of the amino acids throughout the ripening period. Derivatisation with o -phtaldialdehyde and a C₁₈ column were used for chromatographic separations. In order to establish the relationships between the different variables and to detect the most important causes of variability, principal component analysis was applied to the free amino acids data, which reduced to two dimensions where cheese samples from 2 to 60 days and cheeses from 90 to 120 days were distributed dependently of ripening time and coagulant used. Leu, Val, Lys, Gly, Tyr and Asp were correlated with PC1, which separated the samples according to their ripening time. Arg, His, Trp, Ser and Thr were correlated with PC2, which separated the samples according to the coagulant used.     

Polypropylene Fibers and their Effects on Processing Refractory Castables

Polymeric fibers are efficient drying additives for refractory castables as they can reduce the risks of explosion during the first heat-up. When fibers are melted, they increase permeability, enhancing the drying rate and reducing vapor pressure. Despite these benefits, adding fibers can induce mixing and pumping difficulties due to particle entanglement. In the present work, an analysis involving rheology, dynamic permeability, drying and explosion likelihood of polypropylene fiber containing castables is presented. An optimized condition (fiber content and geometry) to maximize the performance of fibers as drying additives and to prevent mixing drawbacks is also highlighted.     

Cylindrical FDTD Analysis of LWD Tools Through Anisotropic Dipping-Layered Earth Media

Electrical logging-while-drilling (LWD) tools are commonly used in oil and gas exploration to estimate the conductivity (resistivity) of adjacent Earth media. In general, Earth media exhibit anisotropic conductivities. This implies that when LWD tools are used for deviated and horizontal drilling, the resulting borehole problem may include dipping-layered media with dipping beds having full 3 times 3 conductivity tensors. To model this problem, we describe a 3-D cylindrical finite-difference time-domain (FDTD) algorithm extended to fully anisotropic conductive media and implemented with cylindrical perfectly matched layers to mimic open-domain problems. The 3-D FDTD algorithm is validated against analytical results in simple formations, showing good agreement, and used to simulate the response of LWD tools through anisotropic dipping beds for various values of anisotropic conductivities and dipping angles     

Random field of initial deflections and strength of thin rectangular plates

The use of an integral measure of initial deflections of thin plates, based on the strain energy, has proved to be of importance in studying the influence of the imperfections on the strength of plates subjected to in-plane compression. The energy measure allows for a straightforward definition of compound modes and for a computational determination of the lower bound strength. The last quantity may be essential for assessment of plate design strength considering the imperfections as a random field.