Search results for "phase angle"
showing 10 items of 25 documents
Nutritional predictors of mortality after discharge in elderly patients on a medical ward
2015
Background: Malnutrition in elderly inpatients hospitalized on medical wards is a significant public health concern. The aim of this study was to investigate nutritional markers as mortality predictors following discharge in hospitalized medical elderly patients. Materials and methods: This is a prospective observational cohort study with follow-up of 48 months. Two hundred and twenty-five individuals aged 60 and older admitted from the hospital emergency room in the past 48 h were investigated at the medical ward in the University hospital in Palermo (Italy). Anthropometric and clinical measurements, Mini-nutritional Assessment (MNA) questionnaire, bioelectrical (BIA) phase angle (PA), gri…
Bioimpedance phase angle indicates catabolism in Type 2 diabetes
2015
Aims Body cell mass is directly proportional to the bioimpedance phase-angle which is an indicator of the amount of electrical charge that cell membranes can hold and is an index of cellular health and function. To evaluate whether the bioimpedance phase angle is relevant for indicating catabolism in people with diabetes and whether it discriminates between people with diabetes receiving different types of therapy. Methods A cross-sectional study was performed in 182 people with Type 2 diabetes and 107 age- and BMI-matched control subjects. The phase angle was measured at 5, 50 and 100 kHz using multifrequency bioimpedance analysis. The phase angles were compared among different diabetes th…
Time dependent viscoelastic rheological response of pure, modified and synthetic bituminous binders
2016
Bitumen is a viscoelastic material that exhibits both elastic and viscous components of response and displays both a temperature and time dependent relationship between applied stresses and resultant strains. In addition, as bitumen is responsible for the viscoelastic behaviour of all bituminous materials, it plays a dominant role in defining many of the aspects of asphalt road performance, such as strength and stiffness, permanent deformation and cracking. Although conventional bituminous materials perform satisfactorily in most highway pavement applications, there are situations that require the modification of the binder to enhance the properties of existing asphalt material. The best kn…
Remote voltage synchronization for wireless Partial Discharge diagnostics
2016
The main objective of this paper is the assessment of the exact phase angle displacement of each Partial Discharge, PD, pulse with respect to the voltage reference waveform. Such problem also referred to as ‘synchronization’ is relevant when the cable is not accessible and the PD measure is carried out in wireless mode. It is well known, that the angle phase shift, due to the propagation phenomenon on the transmission line, can be calculated knowing the line type and length and typical operating conditions of the transmission line. The setup comprises a customized electronic device, the “Phase check”, a server to collect remote measurements and a Look up table to provide corrections to the …
Three-dimensional mapping of the B 1 field using an optimized phase-based method: Application to hyperpolarized 3 He in lungs
2010
A novel method is presented for the three-dimensional mapping of the B1-field of a transmit radio-frequency MR coil. The method is based on the acquisition of phase images, where the effective flip angle is encoded in the phase of the nonselective hard pulse excitation. The method involves the application of a rectangular composite pulse as excitation in a three-dimensional gradient recall echo to produce measurable phase angle variation. However, such a pulse may significantly increase the radio-frequency power deposition in excess of the standard acceptable SAR limits, imposing extremely long TRs (>100 msec), which would result in acquisition times significantly greater than a single brea…
Influence on PD Parameters due to Voltage Conducted Disturbances
2004
In the standard specification of ac dielectric-characteristic measurements of insulating materials, test voltage is prescribed as "approximately sinusoidal" when the highest acceptable deviation of the HV waveform, from the correct sinusoidal shape, is limited to a /spl plusmn/5% tolerance range of the crest factor value. In the field of partial discharge (PD) measurements and their statistical data processing, on which forecasts of long term behavior of components and their reliability are currently carried out, the results of elaborations depend on the voltage wave shape. In this paper, the errors in PD measurements, evaluated at industrial frequencies, due to applied voltages distorted b…
Study of e+e−→pp¯ in the vicinity of ψ(3770)
2014
Using 2917 pb(-1) of data accumulated at 3.773 GeV, 44.5 pb(-1) of data accumulated at 3.65 GeV and data accumulated during a psi(3770) line-shape scan with the BESIII detector, the reaction e(+)e(-) -> p (p) over bar is studied considering a possible interference between resonant and continuum amplitudes. The cross section of e(+)e(-) -> psi(3770) -> p (p) over bar, sigma(e(+)e(-)-> psi(3770) -> p (p) over bar), is found to have two solutions, determined to be (0.059(-0.020)(+0.070) +/- 0.012) pb with the phase angle phi = (255.8(-26.6)(+39.0) +/- 4.8). ( psi(3770) -> p ) = (2.57(-0.13)(+0.12) +/- 0.12) pb with phi = (266.9(-6.3)(+6.1) +/- 0.9)degrees both of which agree with a destructive…
Sign-preserving solutions for a class of asymptotically linear systems of second-order ordinary differential equations
2022
We study multiplicity of solutions to an asymptotically linear Dirichlet problem associated with a planar system of second order ordinary differential equations. The existence of two sign-preserving component-wise solutions is guaranteed when the Morse indexes of the linearizations at zero and at infinity do not coincide, and one of the asymptotic problems has zero-index. The proof is developed in the framework of topological and shooting methods and it is based on a detailed analysis and characterization of the phase angles in a two-dimensional setting.
Phenotypic Aspects of Longevity
2019
Centenarians are individuals who live over the average life span characteristic of their population. The growing number of old people worldwide makes it necessary to identify a good strategy to reach healthy ageing and avoid or delay age-related diseases. The longevity phenotype is the result of a positive combination between genetic, epigenetic, stochastic and lifestyle factors. So, the analysis of all the known parameters that can influence these single elements or their interaction can give new possible elements to delineate a sort of longevity signature. Starting from the easiest biomarkers as the haematochemical values and reaching the study of molecular and cellular components, as the…