Search results for "Potential measurement"

showing 4 items of 4 documents

MetProc: Separating Measurement Artifacts from True Metabolites in an Untargeted Metabolomics Experiment

2019

High-throughput metabolomics using liquid chromatography and mass spectrometry (LC/MS) provides a useful method to identify biomarkers of disease and explore biological systems. However, the majority of metabolic features detected from untargeted metabolomics experiments have unknown ion signatures, making it critical that data should be thoroughly quality controlled to avoid analyzing false signals. Here, we present a postalignment method relying on intermittent pooled study samples to separate genuine metabolic features from potential measurement artifacts. We apply the method to lipid metabolite data from the PREDIMED (PREvención con DIeta MEDi-terránea) study to demonstrate clear remova…

0301 basic medicinePooled QC sampleComputer scienceComputational biology01 natural sciencesBiochemistryArticle03 medical and health sciencesMetabolomicsTandem Mass SpectrometryMetabolomicsUntargeted metabolomics010401 analytical chemistryGeneral ChemistryPotential measurementMeasurement artifactLipidsPredimed0104 chemical sciencesR package030104 developmental biologyUntargeted metabolomicsMetabolomeArtifactsMETABOLIC FEATURESBiomarkersMissing patternChromatography LiquidJournal of Proteome Research
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An approach to single trial analysis of event-related potentials based on signal detection theory.

1996

Abstract The aim of the present paper was to introduce a single trial analysis to event-related potential measurement in order to illuminate the mechanisms behind an impaired P300 amplitude occurring under certain experimental conditions. For this purpose we applied tools from linear system theory and signal detection theory to single trials in an oddball paradigm in order to estimate the amplitude of the positive deflection around the P300 latency following target and nontarget stimuli. According to the density functions of these amplitude distributions we operationally defined ‘P300 absent in target’ (P300 amplitude smaller than an individual threshold under target conditions) as well as …

AdultMaleCommunicationbusiness.industryComputer scienceGeneral NeuroscienceLinear systemBrainElectroencephalographyPotential measurementMiddle AgedP300 amplitudeEvent-Related Potentials P300Neuropsychology and Physiological PsychologyAmplitudeEvent-related potentialPhysiology (medical)HumansDetection theoryFemaleSingle trialbusinessOddball paradigmAlgorithmInternational journal of psychophysiology : official journal of the International Organization of Psychophysiology
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Fall of Potential Measurement of the Earth Resistance in Urban Environments: Accuracy Evaluation

2019

Both Standards EN 50522 and IEEE 81 propose the fall of potential method (FPM) to carry out the measurement of the resistance to earth ( $R_{\text{ES}}$ ) of an earthing system (ES). However, in urban areas, the recommended distances between the ES and auxiliary electrodes are not easy to respect, due to the presence of buildings and tarmac. Furthermore, unknown buried metallic parts and interconnections among ESs could modify the earth potential profile of the area, affecting the measurement results. In this paper, the key-issues that influence the measured $R_{\text{ES}}$ when the FPM is used in an urban environment are presented. A parametric analysis, carried out with Comsol Multiphysic…

Field (physics)Computer science020209 energyMultiphysicsSubstationsurban areas02 engineering and technologyEarth GroundingTopologyfall of potentialIndustrial and Manufacturing Engineering0202 electrical engineering electronic engineering information engineeringGround resistance measurementElectrical and Electronic EngineeringMV/LV substationElectrodesGroundingTarmacresistance measurementGround020208 electrical & electronic engineeringPotential methodEarthPotential measurementEarthing systemSettore ING-IND/33 - Sistemi Elettrici Per L'EnergiaSettore ING-IND/31 - ElettrotecnicaEarth Electrodes Grounding Electric potential Substations Probes Ground resistance measurementElectric potentialControl and Systems EngineeringProbesElectric potential
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Rapid and eco-friendly synthesis of graphene oxide-silica nanohybrids

2014

The increasing interest in Graphene oxide (GO) is due to many issues: the presence of both sp2-conjugated atoms and oxygen-containing functional groups provides a strong hydrophilicity and the possibility to further functionalize it with other molecules (i.e. π-π interactions covalent attachment etc.) [1]. Furthermore since the GO is biocompatible and noncytotoxic many studies have been recently focused on the development of GO-based nanodevices for bioimaging DNA detection drug delivery. Due to their low cytotoxicity and large internal surface area silica nanoparticles have been taken into account as promising material for biolabeling and drug loading/delivery. Particular consideration has recently been demonstrated for GO-silica composites because of the potentialities for electrical applications their chemical inertia and stability toward ions exposure. The possibility to combine the extraordinary properties of GO and silica offers several advantages for the realization of nanoprobes for biological applications and of biosensor [12]. The strategy for the fabrication of GO-nanosilica nanohybrids can be schematized as follows: (i) synthesis of GO by oxidizing graphite powder with the method described by Marcano et al. [3] (ii) Preparation of oxygen-loaded silica nanoparticles by thermal treatments in controlled atmosphere in order to induce high NIR emission at 1272 nm from high purity silica nanoparticles. (iii) preparation of GrO-silica nanohybrid films via rapid solvent casting in water. The nanohybrids were tested by XPS FTIR Raman analysis UV photoluminescence analysis TGA Zeta potential measurements electrical tests AFM and SEM. Several nanohybrids were prepared by combining two different typologies of GO and two different samples of silica.
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