Metodologia modificada para determinação de óxido de titânio como marcador em fezes de bovinos.

JIPE 2013

Análise e gerenciamento de resíduos do pH-SMP.

JIPE 2012

Can MRI measure myelin? Systematic review, qualitative assessment, and meta-analysis of studies validating microstructural imaging with myelin histology

Recent years have seen an increased understanding of the importance of myelination in healthy brain function and neuropsychiatric diseases. Non-invasive microstructural magnetic resonance imaging (MRI) holds the potential to expand and translate these insights to basic and clinical human research, but the sensitivity and specificity of different MR markers to myelination is a subject of debate. To consolidate current knowledge on the topic, we perform a systematic review and meta-analysis of studies that validate microstructural imaging by combining it with myelin histology. We find meta-analytic evidence for correlations between various myelin histology metrics and markers from different MRI modalities, including fractional anisotropy, radial diffusivity, macromolecular pool, magnetization transfer ratio, susceptibility and longitudinal relaxation rate, but not mean diffusivity. Meta-analytic correlation effect sizes range widely, between = 0.26 and = 0.82. However, formal comparisons between MRI-based myelin markers are limited by methodological variability, inconsistent reporting and potential for publication bias, thus preventing the establishment of a single most sensitive strategy to measure myelin with MRI. To facilitate further progress, we provide a detailed characterisation of the evaluated studies as an online resource. We also share a set of 12 recommendations for future studies validating putative MR-based myelin markers and deploying them in vivo in humans

Turn-turn short circuit fault management in permanent magnet machines

This paper presents a systematic study on turn-turn short circuit fault and ways to manage them to provide a basis for comparison of the various options available. The possible methods to reduce the likelihood of the winding SC fault and the fault mitigation techniques related to such faults are discussed. A Finite Element (FE) analysis of a surface-mount Permanent Magnet (PM) machine under application of different mitigation techniques during a turn-turn fault is presented. Both machine and drive structural adaptations for different fault mitigation techniques are addressed. Amongst the investigated fault mitigation techniques, the most promising solution is identified and validated experimentally. It is shown that the shorting terminal method adopting vertical winding arrangement is an effective method in terms of the implementation, reliability and weight

Computationally efficient 3D analytical magnet loss prediction in surface mounted permanent magnet machines

This study proposes a computationally efficient analytical method, for accurate prediction of three-dimensional (3D) eddy current loss in the rotor magnets of surface mounted permanent magnet (SPM) machines considering slotting effect. Subdomain model incorporating stator tooth tips is employed to generate the information on radial and tangential time-derivatives of 2D magnetic field (eddy current sources) within the magnet. The distribution of the eddy current sources in 3D is established for the magnets by applying the eddy current boundary conditions and the Coulomb gauge imposed on the current vector potential. The 3D eddy current distributions in magnets are derived analytically by employing the method of variable separation and the total eddy current loss in the magnets are subsequently established. The method is validated by 3D time-stepped finite element analysis for 18-slot, 8-pole and 12-slot, 8-pole permanent magnet machines. The eddy current loss variations in the rotor magnets with axial and circumferential number of segmentations are studied. The reduction of magnet eddy current loss is investigated with respect to harmonic wavelength of the source components to suggest a suitable segmentation for the rotor magnets in SPM machines

Integrating Greenhouse Gas Emissions Costs in Lifecycle Loss Evaluations: A Case Study for Transmission Lines

Considering the investment volume in the electrical energy infrastructure and the increasing awareness for global warming and climate change, this paper aims to deliver an enhanced transmission line losses evaluation method that integrates true environment financial figures. The enormous volume of transmission lines utilized in power systems across the world provides a considerable potential for energy savings by adopting the idea of “energy-efficient transmission lines.” In this paper the total owning cost (TOC) formula with built-in environmental components is used to assess the relative economic benefit of a high-first-cost, low-loss transmission line unit versus one with a lower first cost and higher losses. The proposed methodology is applied on the Cyprus Power System, by incorporating true financial data and system characteristics.</jats:p

Finite element modelling of shear bands in porous media by means of non-local viscoplasticity

This work presents a consistent numerical approach in the framework of analyzing the localization process in a slope stability problem. An already existing model, embedded in Mechanics of multiphase porous media, is enhanced with local and non-local elasto-viscoplastic constitutive models to obtain regularized numerical solutions. The initiation and the propagation of the shear band are effectively described by means of FEM analysis, regardless of the mesh size adopted. The strain localization process realistically occurs within the shear band failure mode and its size is governed by the internal length variable, which can be directly estimated by experimental approaches