Search results for "thermal [radiation mechanism]"

showing 10 items of 2571 documents

ZrO2 Based materials as photocatalysts for 2-propanol oxidation by using UV and solar light irradiation and tests for CO2 reduction

2018

Abstract Bare ZrO2, Ce doped ZrO2 and Er doped ZrO2 samples have been prepared by a hydrothermal process and have been used as photocatalysts for 2-propanol oxidation reaction in gas solid regime. Moreover, some preliminary tests have been carried out for CO2 reduction. The samples were physico-chemically characterized and both bare and doped ZrO2 based materials resulted active for oxidation and reduction reactions by using UV and solar irradiation. The reactivity results have been correlated with the compositional, structural and morphological features of the photocatalysts.

2-Propanol oxidation; Ce doped ZrO2; CO2 reduction; Er doped ZrO2; Photocatalysis; ZrO2; Catalysis; Chemistry (all)Materials science02 engineering and technology010402 general chemistryPhotochemistry01 natural sciencesRedoxHydrothermal circulationCatalysisCatalysisPropanolchemistry.chemical_compoundPhotocatalysiZrO2Reactivity (chemistry)IrradiationPhotocatalysisDoping2-Propanol oxidationChemistry (all)Er doped ZrO2General Chemistry021001 nanoscience & nanotechnology0104 chemical sciencesCe doped ZrO2chemistryCO2 reductionPhotocatalysis2-Propanol oxidation Ce doped ZrO2 CO2 reduction Er doped ZrO 2 Photocatalysis ZrO2Settore CHIM/07 - Fondamenti Chimici Delle Tecnologie0210 nano-technologyCO2reduction
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Emerging extraction

2015

Traditional extraction methods include usually high temperature treatment (more than 100°C) with the subsequent risk of thermal denaturation or transformation of the target molecules. Moreover, these techniques are very time-consuming and require relatively large quantities of solvents. On the other hand, the use of environmentally friendly technologies has led researchers and the food industry to develop new alternative processes that can extract valuable compounds from different sources and food wastes of different origin. This chapter describes the potential use of emerging technologies such as ultrasound-assisted extraction (UAE), laser ablation, pulsed electric fields (PEF), high volta…

2. Zero hungerThermal denaturationFood industrybusiness.industryEmerging technologies[SDV]Life Sciences [q-bio]010401 analytical chemistryExtraction (chemistry)04 agricultural and veterinary sciences040401 food science01 natural sciencesEnvironmentally friendly0104 chemical sciences0404 agricultural biotechnologyTemperature treatmentSustainabilityEnvironmental scienceExtraction methodsProcess engineeringbusinessComputingMilieux_MISCELLANEOUS
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Enhanced adhesion and in situ photothermal ablation of cancer cells in surface-functionalized electrospun microfiber scaffold with graphene oxide

2017

The physicochemical characteristics of a biomaterial surface highly affect the interaction with living cells. Recently, much attention has been focused on the adhesion properties of functional biomaterials toward cancer cells, since is expected to control metastatic spread of a tumor, which is related to good probability containing the progression of disease burden. Here, we designed an implantable poly(caprolactone)-based electrospun microfiber scaffold, henceforth PCLMF-GO, to simultaneously capture and kill cancer cells by tuning physicochemical features of the hybrid surface through nitrogen plasma activation and hetero-phase graphene oxide (GO) covalent functionalization. The surface i…

3003business.product_categoryCancer therapyPharmaceutical ScienceNanotechnologyBiocompatible Materials02 engineering and technologyCell capture010402 general chemistry01 natural scienceslaw.inventionPlasmalawNeoplasmsMicrofiberCell AdhesionHumansCell adhesionGraphene oxideHybrid materialChemistryGrapheneBiomaterialOxidesAdhesionPhotothermal therapyPhototherapy021001 nanoscience & nanotechnology0104 chemical sciencesPolycaprolactoneCancer cellMCF-7 CellsSurface modificationGraphite0210 nano-technologybusiness
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UAV and GPR Data Integration in Glacier Geometry Reconstruction: A Case Study from Irenebreen, Svalbard

2022

Although measurements of thickness and internal structure of glaciers are substantial for the understanding of their evolution and response to climate change, detailed data about polythermal glaciers, are scarce. Here, we present the first ground-penetrating radar (GPR) measurement data of Irenebreen, and high-resolution DEM and orthomosaic, obtained from unmanned aerial vehicle (UAV) photogrammetry. A combination of GPR and UAV data allowed for the reconstruction of the glacier geometry including thermal structure. We compare different methods of GPR signal propagation speed determination and argue that a common midpoint method (CMP) should be used if possible. Our observations reveal that…

3D modelSvalbardground-penetrating radarcommon midpoint methodScienceQglaciologyunmanned aerial vehicleGeneral Earth and Planetary Sciencestemperate icephotogrammetrythermal structureRemote Sensing
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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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Filling the Gap in the Metallacrown Family: The 9‐MC‐3 Chromium Metallacrown

2021

Abstract In this work, we report on a long‐sought missing complex in the metallacrown family. We synthesized and characterized the novel chromium metallacrown (MC) complex {CrIII(μ 2‐piv)3[9‐MCCr(III)N(shi)‐3](morph)3}⋅MeOH (in which shi3−=salicyl hydroxamate, piv=pivalate, and morph=morpholine). The MC with a 9‐MC‐3 cavity of kinetically inert chromium(III) ions was synthesized by a solvothermal reaction. Magnetization measurements reveal a high spin ground state.

9-MC-3540 Chemistry and allied sciencesCluster Compounds | Hot PaperCommunicationOrganic Chemistrykinetic stabilityStructural integritychemistry.chemical_elementGeneral ChemistrySolvothermal reactionCatalysisCommunicationsIonmetallacrownMagnetizationCrystallographyChromiumchemistry.chemical_compoundstructural integritychemistry540 ChemieMorpholinechromiumGround stateMetallacrownChemistry (Weinheim an Der Bergstrasse, Germany)
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Quantum well intermixing in GaInNAs/GaAs structures

2003

We report on the characteristics of quantum well intermixing in GaInNAs/GaAs structures of differing N content. Rapid thermal annealing combined with SiO2 caps deposited on the surface of the samples is used to disorder 1.3 mum GaInNAs/GaAs multiquantum wells which have been preannealed in-situ to the stage of blueshift saturation. The different effects of two capping layer deposition techniques on the interdiffusion of In-Ga have been compared, particular regarding the role of sputtering processes. The dependence of quantum well intermixing-induced photoluminescence blueshift on N concentration has provided extra information on the intrinsic properties of the GaInNAs/GaAs material system. …

:Science::Physics::Optics and light [DRNTU]Materials sciencePhotoluminescencebusiness.industryAlloyGeneral Physics and Astronomyengineering.materialSettore ING-INF/01 - ElettronicaBlueshiftGallium arsenidechemistry.chemical_compoundchemistrySputteringQuantum well intermixing GaInNAsengineeringOptoelectronicsRapid thermal annealingbusinessSaturation (magnetic)Quantum well
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Effects of rapid thermal annealing on the optical properties of low-loss 1.3μm GaInNAs∕GaAs saturable Bragg reflectors

2004

We report studies of the effect of rapid thermal annealing (RTA) on the optical properties of a low-loss 1.3 mum saturable Bragg reflector (SBR), consisting of a GaInNAs/GaAs single quantum well embedded in an AlAs/GaAs Bragg reflector grown monolithically on a GaAs substrate. RTA gives rise to a blueshift of the photoluminescence (PL) peak (and therefore of the excitonic absorption peak) and an enhancement of PL intensity, while the reflectivity properties including peak reflectivity and bandwidth are not degraded. Temperature dependent photoluminescence measurements show that the RTA-induced blueshift of photoluminescence consists of two components: one originating from the increase of op…

:Science::Physics::Optics and light [DRNTU]PhotoluminescenceMaterials scienceCondensed Matter::Otherbusiness.industrychemical beamPhysics::OpticsGeneral Physics and AstronomyNonlinear opticsCondensed Matter::Mesoscopic Systems and Quantum Hall EffectDistributed Bragg reflectorBlueshiftGallium arsenideCondensed Matter::Materials Sciencechemistry.chemical_compoundchemistryOptoelectronicsSemiconducting galliumRapid thermal annealingbusinessSemiconductor quantum wellsRefractive indexQuantum wellJournal of Applied Physics
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Section: Advanced Composites and Applications (15th February, 2022, Riga, Latvia) : Book of Abstracts

2022

The section ‘Advanced Composites and Applications’ was organized by the Institute for Mechanics of Materials of the University of Latvia (LU MMI) on 15.02.2022 as a part of the annual 80th scientific conference of the University of Latvia. It was organized remotely in Zoom. The official language of the section was English. The duration of the presentation was 10-15 minutes. The section was devoted to the discussion of the recent results within following topics: structure and properties of polymers and polymer-based composites, long-term properties, creep, and environmental ageing, composites for advanced applications, mechanical aspects of technology, multifunctional properties.

:TECHNOLOGY::Engineering mechanics::Mechanical manufacturing engineering [Research Subject Categories]:TECHNOLOGY::Materials science::Functional materials [Research Subject Categories]:TECHNOLOGY::Engineering mechanics::Mechanical and thermal engineering [Research Subject Categories]
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Negative thermal expansion in cuprite-type compounds: A combined synchrotron XRPD, EXAFS, and computational study of Cu2O and Ag2O

2006

Cuprite-type oxides (Cu2O and Ag2O) are framework structures composed by two interpenetrated networks of metal-sharing M4O tetrahedra (M = Cu, Ag). Both compounds exhibit a peculiar negative thermal expansion (NTE) behaviour over an extended temperature range (9 240 K for Cu2O, 30-470 K for Ag2O). High-accuracy synchrotron powder diffraction and EXAFS measurements were performed from 10 K up to the decomposition temperature to understand the nature of the NTE effects. The critical comparison of the diffraction and absorption results concerning the temperature dependence of the interatomic distances and of the atomic vibrational parameters proves to be fundamental in defining the local dynam…

ABSORPTION FINE-STRUCTUREPOWDER DIFFRACTIONExtended X-ray absorption fine structureChemistryThermal decompositionCupriteCharge densityGeneral ChemistryAtmospheric temperature rangeCondensed Matter PhysicsThermal expansionCrystallographyChemical bondNegative thermal expansionPhysics::Atomic and Molecular ClustersSCATTERINGRADIATIONGeneral Materials ScienceThermal expansionTEMPERATUREPowder diffractionJournal of Physics and Chemistry of Solids
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