Concentration effects in the critical temperature of superconducting alloys—Functional integral method

The critical temperatureT _c of a dilute superconducting alloy with transition metal impurities is calculated as a function of the concentration of impurities within the framework of the functional integral formalism. By limiting ourselves to the static approximation, we obtain for log(T _c /T _o ) an expression that reduces to known results in the magnetic and nonmagnetic limits, thus having the character of an interpolating formula between these two extreme cases.     

A mechanically based approach to non-local beam theories

A mechanically based non-local beam theory is proposed. The key idea is that the equilibrium of each beam volume element is attained due to contact forces and long-range body forces exerted, respectively, by adjacent and non-adjacent volume elements. The contact forces result in the classical Cauchy stress tensor while the long-range forces are modeled as depending on the product of the interacting volume elements, their relative displacement and a material-dependent distance-decaying function. To derive the beam equilibrium equations and the pertinent mechanical boundary conditions, the total elastic potential energy functional is used based on the Timoshenko beam theory. In this manner, the mechanical boundary conditions are found coincident with the corresponding mechanical boundary conditions of classical elasticity theory. Numerical applications are also reported.     

Bibliometric analysis to identify an emerging research area: Public Relations Intelligence—a challenge to strengthen technological observatories in the network society

Scientometrics - Nowadays within the global economy, organizations of all kinds require strategic information to ensure that their decision making is competitive in uncertain complex environments....     

Effect of Wind and Slope When Scaling the Forest Fires Rate of Spread of Laboratory Experiments

This paper uses the scaling laws obtained from a Froude Modeling perspective to analyze the variations experienced in the rate of spread of wind-aided and up-slope laboratory fires when changing the size of a scale model. The results have shown that the rate of spread scaling law is no longer verified when working at laboratory scale in steep slopes and high wind speed conditions. The paper also provides a framework for scaling and scale issues in forest fire research.     

Laccase/2,2,6,6‐Tetramethylpiperidinoxyl Radical (TEMPO): An Efficient Catalytic System for Selective Oxidations of Primary Hydroxy and Amino Groups in Aqueous and Biphasic Media

Copper salts/2,2,6,6‐tetramethylpiperidinoxyl radical (TEMPO) catalytic systems enable efficient aerobic oxidations of primary alcohols but they generally show a reduced reactivity in aqueous medium. Herein, we report an oxidative catalytic system composed of Trametes versicolor laccase and TEMPO, which is able to work in buffer solutions at room temperature using ambient air. Although this catalytic system displays great efficiency in aqueous systems, the addition of methyl tert‐butyl ether allows the reduction of TEMPO loading, also enhancing the solubility of hydrophobic compounds. This practical methodology promotes the chemoselective aerobic oxidation of hydroxy or amino groups, leading to interesting organic derivatives such as aldehydes, lactones, hemiaminals or lactams.

     

Distribution of procyanidins and their metabolites in rat plasma and tissues after an acute intake of hazelnut extract

Procyanidins are present in a wide range of dietary foods and their metabolism is well known. Nevertheless, the biological target and their distribution are topics lacking information. The purpose of the present work was to study the metabolism and distribution of procyanidins and their metabolites in rat plasma and different tissues, such as liver, brain, lung, kidney, intestine, testicle, spleen, heart and thymus, after 2 h of an acute intake of hazelnut extract rich in procyanidins (5 g kg(-1) of rat body weight). The interest of an acute intake of procyanidins instead of repeated low doses from daily ingestion of is to achieve a concentration of metabolites in the tissues that allows their detection and quantification. The results showed that catechin and epicatechin-glucuronide, methyl catechin and epicatechin-glucuronide and methyl catechin and epicatechin-sulphate were detected in plasma samples at the μmol level. On the other hand, catechin-glucuronide, methyl catechin-glucuronide and methyl catechin-sulphate were identified in some tissues, such as thymus, intestine, lung, kidney, spleen and testicle at the nmol level. Procyanidins with a low grade of polymerization (dimers and trimers) were detected in plasma samples and the intestine. Additionally, a wide range of simple aromatic acids from fermentation by the colonic microflora was detected in all tissues studied.     

Animal performance and milk fatty acid profile of dairy goats fed diets with different unsaturated plant oils

The effect of supplementing a basal diet with 1 of 3 plant oils on productive efficiency and milk fatty acid composition was studied in dairy goats. Sixteen Malagueña goats were used in a 4 × 4 Latin square experiment with 21-d periods and 4 goats per treatment. The basal diet comprised 30% alfalfa hay and 70% pelleted concentrate. Experimental treatments were control (basal diet without added oil) and the basal diet supplemented with 48 g/d of high oleic sunflower oil (HOSFO), regular sunflower oil (RSFO), or linseed oil (LO). Dry matter intake and body weight were not affected by treatments. Milk production was higher in HOSFO treatment and milk fat content was higher in RSFO and LO treatments, although no differences in milk energy production or milk renneting properties were found. The RSFO and LO treatments increased the proportion of vaccenic acid in milk fat more so than the HOSFO diet, and rumenic acid followed the same pattern. The content of trans10-18:1 remained low in all experimental diets (<0.7% of total fatty acid methyl esters) although HOSFO and RSFO diets increased it. The variations in the fatty acid profiles observed with the 4 diets, mainly the unsaturated fatty acid isomer contents, are extensively discussed. Compared with that in the control diet, the n-6:n-3 fatty acid ratio in milk fat substantially decreased with the LO, increased with RSFO, and did not change with HOSFO. The addition of moderate amounts of LO to the diets of dairy goats has favorable effects on milk fatty acid composition from the point of view of the human consumer, without negative effects on animal performance.