Search results for " Electrical conductivity"

showing 10 items of 13 documents

Thermomineral waters of Greece: geochemical characterization

2020

75 °C). In terms of pH most results vary from 5.5 to 823 °C) ii) warm (23 40 °C) iii) thermal (40 75 °C) and iv) hyperthermal (&gtfew springs show either very low pH (&lt10) proposing serpentinization processes. Regarding TDS concentrations collected waters can be subdivided into low salinity (up to 1.5 g/L) brackish (up to 20 g/L) and saline (up to 43 g/L). The medium high salinities can be justified by mixing with sea water and/or strong waterrock interaction processes. Isotope composition of O and H ranges from 12.7 to +2.7 ‰ SMOW and from 91 to +12 ‰ SMOW respectively and is generally comprised between the Global Meteoric Water Line and the East Mediterranean Meteoric Water Line. Only few water samples show a positive shift for δ18O possibly related to high temperature waterrock interaction processes. Carbon dioxide (18 997000 μmol/mol) or N2 (1100 989000 μmol/mol) or CH4 (&ltMany geothermal areas of Greece are located in regions affected by Miocene or Quaternary volcanism and in continental basins characterised by elevated heat flow. Moreover the majority of them is found along the coast as well as in islands of the Aegean Sea and thus thermal water is often brackish to saline due to marine intrusion into costal aquifer. In the present study almost 300 thermal and cold mineral water samples were collected along the Hellenic territory with their physicochemical parameters (temperature pH electrical conductivity and Eh) and the amount of bicarbonates (titration with 0.1N HCl) being determined in situ. Additionally gases found either in free or dissolved phase were sampled. Both water and gas samples were analysed at the INGVPa laboratories for major ions (Ion Chromatography) silica (Inductively Coupled Plasma Optical Emission Spectrometry) chemical composition of free and dissolved gases (Gas Chromatography) water isotopes (O and H) and carbon and helium isotopes of free and dissolved gases (Mass Spectrometry). The temperature of the investigated waters ranges from 6.5 to 98°C pH from 1.96 to 11.98 whilst Total Dissolved Solids (TDS) from 0.06 to 43 g/L. Based on the temperature parameter waters can be divided into four groups: i) cold (&lt0.5 913000 μmol/mol) are the prevailing gas species found in the studied sites. The δ13CCO2 values ranged from 20.1 to +8.5 ‰ whilst the isotope ratio of He from 0.21 to 6.71 R/RA.4) suggesting interaction with H2Srich gases or very high pH values (&gtSettore GEO/08 - Geochimica E Vulcanologia
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Differenziazione e quantificazione dei carbonati litogenici e pedogenici di Gypsisuoli forestali attraverso l'analisi isotopica

2004

Gli autori riferiscono sui tipi e sui modelli di genesi dei carbonati dei suoli, attraverso l’uso degli isotopi del 13C. Lo studio è stato condotto in un’area dell’interno collinare argilloso siciliano, su suoli che evolvono sui depositi evaporitici della Serie Gessoso-Solfifera. Sono stati scelti cinque pedon su litotipi calcarei e non. I pedon sono stati descritti in campo e campionati secondo la sequenza degli orizzonti genetici; sui campioni di suolo sono state eseguite le seguenti analisi: tessitura, reazione, conducibilità elettrica, gesso, carbonio organico ed inorganico. Inoltre, parallelamente sono state eseguite le analisi isotopiche del carbonio organico ed inorganico. I risultat…

Authors report on forms and soil carbonate formation models as detected by 13C isotopes. This study was carried out in a clayey hilly area of central Sicily where soils have developed on evaporitic deposits of “Gessoso-Solfifera” Formation. Four pedons were selected both on calcareous and no calcareous lithotypes. Pedons were described in field and sampled according to sequence of genetic horizons. Soil samples were analyzed to investigate the following properties: particle size distribution reaction electrical conductivity gypsum organic and inorganic carbon. Moreover isotopic analyses were performed on organic and inorganic carbon. Results allow us to describe the complex relationships between biotic and abiotic soil components. In addition models of calcic horizon formation and their implication in soil classification were defined.Settore AGR/13 - Chimica Agraria
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Increased conductivity of a hole transport layer due to oxidation by a molecular nanomagnet

2008

Thin film transistors based on polyarylamine poly?N,N?-diphenyl-N,N ?bis?4-hexylphenyl?- ?1,1?biphenyl?-4,4?-diamine ?pTPD? were fabricated using spin coating in order to measure the mobility of pTPD upon oxidation. Partially oxidized pTPD with a molecular magnetic cluster showed an increase in mobility of over two orders of magnitude. A transition in the mobility of pTPD upon doping could also be observed by the presence of a maximum obtained for a given oxidant ratio and subsequent decrease for a higher ratio. Such result agrees well with a previously reported model based on the combined effect of dipolar broadening of the density of states and transport manifold filling. Peer Reviewed

Electron mobilityMaterials scienceOrganic compounds.Analytical chemistryDipolar broadeningGeneral Physics and AstronomySpin coatingHole mobilityElectronic density of statesConductivityOxidacióCompostos orgànicsElectrical resistivity and conductivity:FÍSICA [UNESCO]Molecular clustersOrganic compoundsOxidationDopingElectrical conductivityOxidation.Molecular nanomagnetMolecular magnetic clusterMolecular magnetism Nanostructured materialsSpin coatingDopingUNESCO::FÍSICAElectric conductivity.Thin film transistorsNanostructured materialsConductivitat elèctricaNanomagnet:Enginyeria electrònica::Microelectrònica [Àrees temàtiques de la UPC]Doping ; Electrical conductivity ; Electronic density of states ; Hole mobility ; Molecular clusters ; Molecular magnetism Nanostructured materials ; Organic compounds ; Oxidation ; Spin coating ; Thin film transistorsDensity of statesNanostructured materials.Hole transport layerMaterials nanoestructuratsOrder of magnitude
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Multifunctional properties of nanocomposites made by 1D and 2D graphene based fillers

2015

High aspect ratio graphene based fillers with different dimensionalities showed the ability to greatly modify rheological, mechanical, thermal and electrical properties of polymers at very low content. In this work, the effect of filler dimensionality on the multifunctional properties of an epoxy matrix reinforced by both carbon nanotubes (1D) and graphite nanoplatelets (2D) have been investigated across the percolation region. Keywords-- Carbon nanotube, Graphite nanoplatelet, nanocomposites, mechanical properties, ...

Materials scienceNanocompositeCarbon nanotube; electrical conductivity; Graphite nanoplatelet; mechanical properties; nanocompositeselectrical conductivityGrapheneMechanical properties of carbon nanotubesCarbon nanotubeengineering.materialmechanical propertiesYoung's modulus carbon nanotubes glass transition graphene graphite nanocomposites rheology thermal expansionCarbon nanotubelaw.inventionCondensed Matter::Materials SciencelawFiller (materials)PercolationnanocompositesengineeringGraphite nanoplateletGraphiteComposite materialGraphene oxide paper
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A new route for the preparation of flexible skin–core poly(ethylene-co-acrylic acid)/polyaniline functional hybrids

2011

Abstract Surface modification of polymeric films is a way to obtain final products with high performance for many specific and ad hoc tailored applications, e.g. in functional packaging, tissue engineering or (bio)sensing. The present work reports, for the first time, on the design and development of surface modified ethylene–acrylic acid copolymer (EAA) films with polyaniline (PANI), with the aim of inducing electrical conductivity and potentially enable the electronic control of a range of physical and chemical properties of the film surface, via a new “grafting from” approach. In particular, we demonstrate that PANI was successfully polymerized and covalently grafted onto flexible EAA su…

MorphologyMaterials Chemistry2506 Metals and AlloysMaterials sciencePolymers and PlasticsPolyanilineGeneral Chemical EngineeringHybrid polymersBiochemistrychemistry.chemical_compoundX-ray photoelectron spectroscopyPolyanilinePolymer chemistryChemical surface modificationElectrical conductivityPolyaniline Chemical surface modification Hybrid polymers Morphology Electrical conductivityMaterials ChemistryCopolymerEnvironmental ChemistryChemical Engineering (all)Fourier transform infrared spectroscopyAcrylic acidChemistry (all)General ChemistryChemical engineeringchemistryPolymerizationSurface modificationSettore CHIM/07 - Fondamenti Chimici Delle TecnologieChemical surface modification; Electrical conductivity; Hybrid polymers; Morphology; Polyaniline; Materials Chemistry2506 Metals and Alloys; Polymers and Plastics; Chemistry (all); Chemical Engineering (all); Environmental Chemistry; BiochemistryHybrid materialReactive and Functional Polymers
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Structural, electronic, and electrical properties of an Undoped n-Type CdO thin film with high electron concentration

2014

Transparent conducting metal oxides (TCOs) combine the properties of optical transparency in the visible region with a high electrical conductivity. They are a critical component as the window electrode in liquid crystal and electroluminescent display devices, as well as in many designs of solar cells now under development. Sn-doped In2O3 is currently the most important TCO, but it suffers from some drawbacks. These include the high cost of indium, weak optical absorption in the blue-green region, as well as chemical instability that leads to corrosion phenomena in organic light-emitting devices. Indium tin oxide (ITO) films are also brittle and of relatively low durability. A number of oth…

Organic light-emitting devices Optical propertiesMaterials scienceDisplay deviceElectroluminescent display deviceHigh electron concentrationCdO; semiconductor; TCOchemistry.chemical_elementChemical vapor depositionAtomic force microscopyElectric conductivityElectrical resistivity and conductivityChemical vapor depositionLight absorptionThin filmPhysical and Theoretical ChemistryThin filmCdOHigh electrical conductivitybusiness.industryDegenerate semiconductorFree electron concentrationsemiconductorSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsIndium tin oxideElectroluminescent displayPhotoelectron spectroscopyGeneral EnergychemistryLiquid crystalTCOTinElectrodeOptoelectronicsX ray diffraction Conducting metal oxidebusinessTinLuminescence measurementIndium
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Nanocarbon broadband analysis, temperature dependent dielectric properties and percolation thresholds

2013

The results of a broadband dielectric investigation of multi-walled CNT (MWCNT)/epoxy resin composites in wide temperature range from room temperature to 450 K are reported. Far below the percolation threshold (0.25 wt% MWCNT) the dielectric properties of the composite are mostly determined by alpha relaxation in pure polymer matrix. Close to the percolation threshold the composite shows the negative temperature coefficient (NTC) effect in the temperature region, where the pure polymer matrix becomes conductive. The activation energy increases with the MWCNT concentration far below the percolation threshold and decreases close to it (1.5 wt% MWCNT). The dielectric analysis of the MWCNT/epox…

Settore ING-IND/22 - Scienza E Tecnologia Dei Materialicarbon nanotubes dielectric relaxation electrical conductivity filled polymers nanocomposites percolation permittivity resinsSettore CHIM/02 - Chimica Fisica
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Exploring the Simultaneous Effect of Total Ion Concentration and K:Ca:Mg Ratio of the Nutrient Solution on the Growth and Nutritional Value of Hydrop…

2022

Nutrient-efficient plants and agricultural systems could tackle issues resulting from conventional agriculture. Spiny chicory (Cichorium spinosum L.), a very adaptive, wild edible vegetable, is gaining commercial interest as a functional food. Floating-raft hydroponics is a method commonly used for the commercial cultivation of leafy vegetables due to numerous advantages compared to soil cultivation. In this paper, the simultaneous effects of different potassium, calcium and magnesium ratios and different electrical conductivity (EC) levels on the growth and mineral composition of hydroponically grown C. spinosum were investigated. Four nutrient solutions (NS) were compared, two NS with low…

electrical conductivitystamnagathihydroponics; stamnagathi; floating; macrocation ratio; electrical conductivitymacrocation ratiohydroponicAgronomy and Crop SciencefloatingAgronomy
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Comparative environmental analysis of soil sampling methods in precision agriculture for lime application in Paraná State, Brazil

2020

Precision agriculture (PA) provides techniques that favour the localized application of inputs allowing their rational use. This makes the PA a potential indicator of reduced operational costs, input volume, and environmental impacts. The objective of this study was to evaluate and compare the environmental effects of three different sampling methods used in PA for the lime application. The first sampling method evaluated was the grid sampling (GS). It was performed at a density of one sample per hectare in a 100×100 m georeferenced grid. The second method was the directed sampling, that was performed after defining the management zones by soil apparent electrical conductivity (ECa) using a…

environmental impact management zones sample grids soil apparent electrical conductivityarticlesarticlemanagement zones15. Life on landsoil apparent electrical conductivityenvironmental impact management zones sample grids soil apparent electrical conductivity.environmental impactsample grids6. Clean water
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A NEW ROUTE TO OBTAIN PANI-EAA FLEXIBLE FILMS

2010

hybrid polymerelectrical conductivitychemical surface modificationmorphologypolyaniline chemical surface modification hybrid polymers morphology electrical conductivitypolyaniline
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