Search results for "angles"

Apolipoprotein E isoforms and the development of low and high Braak stages of Alzheimer's disease-related lesions

1999

In recent research, apolipoprotein-E (apoE) polymorphism has been shown to influence the formation of neurofibrillary changes and the accumulation of beta/A4-amyloid, the histopathological hallmarks of Alzheimer's disease (AD). Clinical studies associate the apoE allele epsilon4 with earlier onset of the disease, although the clinical speed of progression remains unchanged. Time course estimates have also provided evidence which indicates that the clinical phase of AD constitutes only 10-20% of the total time span needed for the development of this slowly progressing degenerative brain disorder. Due to the lack of reliable clinical tests for the detection of pre-symptomatic stages of AD, we…

Current transformers effects on the measurement of harmonic active power in LV and MV networks

2011

The harmonic active power is used to determine the location of polluting loads, the direction of harmonic power flow and to estimate how consequential a certain current harmonic source is. The highest uncertainties, when measuring harmonic active power, are introduced by the current and voltage transducers. This paper presents experimental results which show the impact of current transformers (CTs) on the accuracy of the harmonic power measurements. An expression for the evaluation of the power error in distorted conditions was developed which can be easily utilized in the case of linear current transducers. It is shown how CTs cannot be considered linear transducers and how the higher the …

Fatigue fracture planes and expected principal stress directions under biaxial variable amplitude loading

2005

Fatigue behaviour under multiaxial variable amplitude loading can be examined by applying the failure criteria based on the critical plane approach. Positions of the critical plane can be determined in relation to the principal stress or strain directions. In the present paper, the expected directions of the principal stresses under proportional and non-proportional loading have been obtained by averaging the instantaneous values of the Euler angles through special weight functions. The known weight functions based on stress parameters appear not to be efficient for each loading or material being analysed. Thus, the authors consider new weight functions based on energy parameters. The prese…

Critical Fracture Plane Under Multiaxial Random Loading by Means of Euler Angles Averaging

1999

ABSTRACT Several authors have experimentally observed that the position of the fatigue fracture plane strongly depends on the directions of the principal stresses or strains. The expected principal stress directions under multiaxial random loading are obtained herein by averaging the instantaneous values of the three Euler angles through some suitable weight functions, in order to take into account the main factors influencing the fatigue fracture behaviour. Then the correlation between such theoretical principal directions and the experimental fracture plane is examined for some biaxial random fatigue tests.

Existence of a traveling wave solution in a free interface problem with fractional order kinetics

2021

Abstract In this paper we consider a system of two reaction-diffusion equations that models diffusional-thermal combustion with stepwise ignition-temperature kinetics and fractional reaction order 0 α 1 . We turn the free interface problem into a scalar free boundary problem coupled with an integral equation. The main intermediary step is to reduce the scalar problem to the study of a non-Lipschitz vector field in dimension 2. The latter is treated by qualitative topological methods based on the Poincare-Bendixson Theorem. The phase portrait is determined and the existence of a stable manifold at the origin is proved. A significant result is that the settling time to reach the origin is fin…

R/C columns strengthened by means of steel angles and battens: testing, modeling and design

2010

PETTERDITE, THE Cr-DOMINANT ANALOGUE OF DUNDASITE, A NEW MINERAL SPECIES FROM DUNDAS, TASMANIA, AUSTRALIA AND CALLENBERG, SAXONY, GERMANY

2000

Petterdite is a newly discovered hydrated lead chromium hydroxyl carbonate, the Cr 3+ -dominant analogue of dundasite, with a formula PbCr 2 (CO 3 ) 2 (OH) 4 ·H 2 O. The type locality is the Red Lead mine, on the Zeehan–Dundas mining field in northwestern Tasmania, Australia. The mineral also occurs in small amounts at the Callenberg nickel deposit, Saxony, Germany. Petterdite forms thin crusts made up of tiny platy crystals up to about 15 μm across, associated with crocoite and anglesite at the type locality, and with crocoite, cerussite, bindheimite, pyromorphite, and relict galena at Callenberg. The petterdite crusts are pale greyish to pinkish violet and non-fluorescent; they have an ea…

The Use of Accelerometers and Gyroscopes to Estimate Hip and Knee Angles on Gait Analysis

2014

In this paper the performance of a sensor system, which has been developed to estimate hip and knee angles and the beginning of the gait phase, have been investigated. The sensor system consists of accelerometers and gyroscopes. A new algorithm was developed in order to avoid the error accumulation due to the gyroscopes drift and vibrations due to the ground contact at the beginning of the stance phase. The proposed algorithm have been tested and compared to some existing algorithms on over-ground walking trials with a commercial device for assisted gait. The results have shown the good accuracy of the angles estimation, also in high angle rate movement.

"One-touch" voltammetry of microparticles for the identification of corrosion products in archaeological lead

2011

Voltammetry of microparticles is applied to the identification of lead corrosion products by means of an essentially non-invasive 'one-touch' technique based on the use of graphite pencil. This methodology permits the mechanical attachment of few nanograms of sample from the surface of lead archaeological artefacts to a paraffin-impregnated graphite electrode, which, upon immersion in aqueous electrolytes, provides distinctive voltammetric responses for litharge and cotunnite- anglesite-, cerusite-based corrosion products. The reported method is applied to the identification of corrosion products in archaeological lead pieces from different Iberian sites in Valencia (Spain). © 2011 WILEY-VC…

Azure C Targets and Modulates Toxic Tau Oligomers.

2018

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder affecting millions of people worldwide. Therefore, finding effective interventions and therapies is extremely important. AD is one of over 20 different disorders known as tauopathies, characterized by the pathological aggregation and accumulation of tau, a microtubule-associated protein. Tau aggregates are heterogeneous and can be divided into two major groups: large metastable fibrils, including neurofibrillary tangles, and oligomers. The smaller, soluble and dynamic tau oligomers have been shown to be more toxic with more proficient seeding properties for the propagation of tau pathology as compared to the …