New generation of cable screw connectors for electrical power engineering systems

The article presents a material analysis for a new generation of cable screw connectors with shear bolts designed for not only 1st and 2nd class of cables but also 5tth class of aluminium and copper conductors that have not been previously supported. The set of properties of aluminium series 6xxx designated for screw connectors production has been determined. Finite Element Method (FEM) simulation of the controlled shear of the bolt at the body of the screw connector has been carried out. The repeatability of the bolt shear in the actual conditions was also conducted in order to verify the prototypes of the new generation of cable screw connectors

Research on the threaded connection system from AlMgSi alloy for electrical power cables under various clamping loads

This article presents strain gauge tests showing the force loads in the connection system of power cables, with AlMgSi sheer bolts. Among others, the analysis of the influence of the tightening torque of the clamping unit on the distribution of forces and the evaluation of the strain in the entire system was carried out. The knowledge of the force conditions and loads in the threaded connection system allowed to develop, with the use of Finite Element Method (FEM) modelling, the optimal geometry and material of elements for the power cable connection system

A Re-Evaluation of the nuclear Structure Function Ratios for D, He, Li, C and Ca

We present a re-evaluation of the structure function ratios F2(He)/F2(D), F2(C)/F2(D) and F2(Ca)/F2(D) measured in deep inelastic muon-nucleus scattering at an incident muon momentum of 200 GeV. We also present the ratios F2(C)/F2(Li), F2(Ca)/F2(Li) and F2(Ca)/F2(C) measured at 90 GeV. The results are based on data already published by NMC; the main difference in the analysis is a correction for the masses of the deuterium targets and an improvement in the radiative corrections. The kinematic range covered is 0.0035 < x < 0.65, 0.5 < Q^2 <90 GeV^2 for the He/D, C/D and Ca/D data and 0.0085 < x < 0.6, 0.84 < Q^2 < 17 GeV^2 for the Li/C/Ca ones.Comment: 6 pages, Latex, 3 figures as uuencoded compressed tar file included at the end, in case of problems contact [email protected] (Antje Bruell

Percepção dos consumidores relativamente à carne de bovino: critérios de escolha a partir de grupos de discussão

Nas economias desenvolvidas, a segurança dos alimentos, o bem‑estar animal e o ambiente têm vindo a assumir relevância nas preocupações dos consumidores. Procurámos saber, através da metodologia dos grupos de discussão (focus groups) realizados em duas cidades de Portugal, Lisboa e Porto, as preocupações e perceções dos consumidores relativamente a estes atributos, os quais são essencialmente acreditados. Este conhecimento é fundamental para a aplicação posterior de métodos de preferências declaradas. Foi ainda possível obter, com base em exercícios de seleção entre carnes diferenciadas, e através de um modelo logit, intervalos de preços passíveis de serem utilizados posteriormente na definição de cenários em experiências de escolha (método de preferências declaradas) -----ABSTRACT-----In developed economies, food safety, animal welfare and the environment have become relevant consumers’ concerns. We conducted several focus groups in two Portuguese cities, Lisboa and Porto, in order to get participants perceptions and concerns for these attributes, which are essentially credence attributes. This knowledge is critical for the subsequent application of stated preference methods. It was also possible to estimate, based on exercises of selection among different meats, and through a logit model, price ranges that could be used in the definition of scenarios for choice experiments (stated preference method)info:eu-repo/semantics/publishedVersio

Influence of plastic deformation on the change of electrical and mechanical properties oxygen-free (OF) copper and copper alloy wires

This article is devoted to the comparison of changes in mechanical and electrical properties due to the applied deformation of copper and copper alloy rods. Bars from four different production technologies were deformed in the drawing process, including oxygen-free (OF) copper, electrolytic copper ETP, copper from cable granulate and silver copper with a high silver content up to 15 wt. % obtained in laboratory technology. The article presents the chemical purity, physical and electrical properties of rods before deformation. The summary of the research on the selected materials are changes in mechanical properties and electrical conductivity as a function of deformation up to 3,5 on a logarithmic scale and the coefficient of electromechanical efficiency WEM