Search results for "TEMPERATURE"

showing 10 items of 3798 documents

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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The impact of weather on COVID-19 pandemic.

2021

AbstractRising temperature levels during spring and summer are often argued to enable lifting of strict containment measures even in the absence of herd immunity. Despite broad scholarly interest in the relationship between weather and coronavirus spread, previous studies come to very mixed results. To contribute to this puzzle, the paper examines the impact of weather on the COVID-19 pandemic using a unique granular dataset of over 1.2 million daily observations covering over 3700 counties in nine countries for all seasons of 2020. Our results show that temperature and wind speed have a robust negative effect on virus spread after controlling for a range of potential confounding factors. T…

2019-20 coronavirus outbreakCoronavirus disease 2019 (COVID-19)ScienceSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2)Social behaviourWindWind speedArticleHerd immunityRisk FactorsPandemicHumansSocial BehaviorPandemicsWeatherMultidisciplinarySARS-CoV-2QRTemperatureCOVID-19HumidityEnvironmental sciencesEnvironmental social sciencesGeographyMedicineDemographic economicsSeasonsScientific reports
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Stabilization of unilamellar catanionic vesicles induced by β-cyclodextrins: A strategy for a tunable drug delivery depot.

2018

The limited stability of catanionic vesicles has discouraged their wide use for encapsulation and controlled release of active substances. Their structure can easily break down to form lamellar phases, micelles or rearrange into multilamellar vesicles, as a consequence of small changes in their composition. However, despite the limited stability, catanionic vesicles possess an attractive architecture, which is able to efficiently encapsulate both hydrophobic and hydrophilic molecules. Therefore, improving the stability of the vesicles, as well as the control on unilamellar structures, are prerequisites for their wider application range. This study focuses on the impact of β-cyclodextrins fo…

3003DepotPharmaceutical Science02 engineering and technology010402 general chemistry01 natural sciencesMicelleDiffusionSurface-Active AgentsDrug Delivery SystemsCyclodextrinLamellar structureUnilamellar Liposomeschemistry.chemical_classificationCatanionic vesiclesCyclodextrinChemistryCetrimoniumVesiclebeta-Cyclodextrinstechnology industry and agricultureTemperatureSodium Dodecyl SulfateCatanionic vesicles; Cyclodextrin; Diffusion; NMR; Self-assembly; 3003Self-assembly021001 nanoscience & nanotechnologyCatanionic vesicleControlled releaseNMR0104 chemical sciencesChemical engineeringSettore CHIM/09 - Farmaceutico Tecnologico ApplicativoDrug deliveryCetrimonium Compoundslipids (amino acids peptides and proteins)Self-assembly0210 nano-technologyInternational journal of pharmaceutics
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Mossbauer spectroscopic study of the thermal spin crossover in [Fe(II)(isoxazole)(6)](ClO(4))(2)

2008

The (57)Fe Mossbauer spectroscopy of mononuclear [Fe(II)(isoxazole)(6)](ClO(4))(2) has been studied to reveal the thermal spin crossover of Fe(II) between low-spin (S = 0) and high-spin (S = 2) states.Temperature-dependent spin transition curves have been constructed with the least-square fitted data obtained from the Mossbauer spectra measured at various temperatures between 84 and 270 K during a cooling and heating cycle. This compound exhibits an unusual temperature-dependent spin transition behaviour with T(C)(down arrow) = 223 and T(C)(up arrow) = 213 K occurring in the reverse order in comparison to those observed in SQUID observation and many other spin transition compounds. The comp…

5-BIS(PYRIDIN-2-YL)-1Phase transitionMossbauer spectroscopySpin transition2Inorganic compoundsABPT=4-AMINO-3chemistry.chemical_compoundMOLECULESNuclear magnetic resonanceSpin crossoverMössbauer spectroscopyMagnetic propertiesPERCHLORATEGeneral Materials Science4-TRIAZOLEIsoxazoleSpin (physics)Mössbauer effectORDER-DISORDER PHENOMENABIS(3-AMINOPROPYL)(2-PYRIDYLMETHYL)AMINECOMPOUNDGeneral ChemistryAtmospheric temperature rangeCondensed Matter PhysicsSTATECrystallographychemistryPhase transitionsPHASE-TRANSITIONCondensed Matter::Strongly Correlated ElectronsCOMPLEXESLIGANDSABPT=4-AMINO-35-BIS(PYRIDIN-2-YL)-124-TRIAZOLEJournal of Physics and Chemistry of Solids
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Unexpected Behavior of Enaminones: Interesting New Routes to 1,6-Naphthyridines, 2-Oxopyrrolidines and Pyrano[4,3,2-de][1,6]naphthyridines

2012

Reaction of enaminones 1a–d with 2-aminoprop-1-ene-1,1,3-tricarbonitrile (2) in the presence of AcOH/NH4OAc afforded 7-amino-5-oxo-5,6-dihydro-1,6-naphthyridine-8-carbonitrile derivatives 9a–d. On the other hand, 2-aminopyrano[4,3,2-de] [1,6]naphthyridine-3-carbonitriles 20a–c,e were the only obtained products from the reactions of 1a–d with 2 in the presence of AcOH/NaOAc, while 1d afforded [3,5-bis-(4-chloro-benzoyl)-phenyl]-(4-chloro-phenyl)-methanone 21 under the same condition. The reaction of 2 with diethyl acetylenedicarboxylate in the presence of AcOH/NH4OAc afforded (4-cyano-5-dicyanomethylene-2-oxo-2,5-dihydro-1H-pyrrol-3-yl)-acetic acid eth…

7-amino-5-oxo-56-dihydro-16-naphthyridine-8-carbonitrileMagnetic Resonance Spectroscopy2-aminoprop-1-ene-113-tricarbonitrileMolecular StructureChemistryOrganic ChemistryPharmaceutical ScienceEthyl esterMedicinal chemistryArticleAnalytical Chemistrylcsh:QD241-441Diethyl acetylenedicarboxylate3-amino-2-cyanopent-2-enedinitrilelcsh:Organic chemistryChemistry (miscellaneous)enaminonesNitrilesDrug DiscoveryTransition TemperatureMolecular Medicineenaminones; 3-amino-2-cyanopent-2-enedinitrile; 7-amino-5-oxo-56-dihydro-16-naphthyridine-8-carbonitrile; 2-aminoprop-1-ene-113-tricarbonitrileNaphthyridinesPhysical and Theoretical ChemistryMolecules
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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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Quantum-chemical determination of Born–Oppenheimer breakdown parameters for rotational constants: the open-shell species CN, CO+ and BO

2013

The quantum-chemical protocol for computing Born-Oppenheimer breakdown corrections to rotational constants in the case of diatomic molecules is extended to open-shell species. The deviation from the Born-Oppenheimer equilibrium rotational constant is obtained by considering three contributions: the adiabatic correction to the equilibrium bond distance, the electronic contribution to the moment of inertia requiring the computation of the rotational g-tensor, and the so-called Dunham correction. Values for the Born-Oppenheimer breakdown parameters of CN, CO+, and BO in their (2)sigma(+) electronic ground states are reported based on coupled-cluster calculations of the involved quantities and …

AB INITIO CALCULATIONSChemistryBorn–Huang approximationBiophysicsBorn–Oppenheimer approximationRotational transitionRotational temperatureCondensed Matter PhysicsROTATIONAL CONSTANTSDiatomic moleculesymbols.namesakesymbolsBorn-Oppenheimer breakdown correctionRotational spectroscopyPhysics::Chemical PhysicsPhysical and Theoretical ChemistryAtomic physicsRotational partition functionMolecular BiologyOpen shellMolecular Physics
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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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Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution

2020

Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Open Access funding provided by Max Planck Society.--All authors: Kim, Jae-Young; Krichbaum, Thomas P.; Broderick, Avery E.; Wielgus, Maciek; Blackburn, Lindy; Gómez, José L.; Johnson, Michael D.; Bouman, Katherine L.; Chael, Andrew; Akiyama, Kazunori; Jorstad, Svetlana; Marscher, Alan P.; Issaoun, Sara; Janssen, Michael; Chan, Chi-kwan; Savolainen, Tuomas; Pesce, Dominic W.; Özel, Feryal; Alberdi, Antxon; Alef, Walt…

ACTIVE GALACTIC NUCLEIBrightnessActive galactic nucleusactive [Galaxies]Astrophysics::High Energy Astrophysical PhenomenaAstronomygalaxies: activeAstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysics01 natural sciencesSubmillimeter ArrayFLOWSSCALE CIRCULAR-POLARIZATION0103 physical sciencesVery-long-baseline interferometryBlazar010303 astronomy & astrophysicsAstrophysics::Galaxy AstrophysicsPhysicsEvent Horizon Telescope[PHYS]Physics [physics]Jet (fluid)010308 nuclear & particles physicsAstronomy and AstrophysicsFLAREgalaxies: jetsindividual: 3C 279 [Galaxies]LONGVARIABILITYgalaxies: individual: 3C 279GAMMA-RAYQUASARS13. Climate actionSpace and Planetary Sciencetechniques: interferometricBrightness temperatureACCRETION DISKSinterferometric [Techniques]jets [Galaxies]RELATIVISTIC JETS[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]Astronomy & astrophysics
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Stabilized Naked Sub-nanometric Cu Clusters within a Polymeric Film Catalyze C-N, C-C, C-O, C-S, and C-P Bond-Forming Reactions

2015

[EN] Sub-nanometric Cu clusters formed by endogenous reduction of Cu salts and Cu nanoparticles are active and selective catalysts for C−N, C−C, C−O, C−S, and C−P bond-forming reactions. Sub-nanometric Cu clusters have also been generated within a polymeric film and stored with full stability for months. In this way, they are ready to be used on demand and maintain high activity (TONs up to 104 ) and selectivity for the above reactions. A potential mechanism for the formation of the sub-nanometric clusters and their electronic nature is presented.

ARYL HALIDESTECNOLOGIA DE ALIMENTOSDIAMINE LIGANDSULLMANNHeterogeneous catalysisBiochemistryCatalysisCoupling reactionCatalysisMECHANISMSColloid and Surface ChemistryQUIMICA ORGANICAOn demandPolymer chemistryOxidationHigh activityOrganic chemistryPotential mechanismTEMPERATURECu nanoparticlesChemistryGeneral ChemistryHETEROGENEOUS CATALYSISCROSS-COUPLING REACTIONSGOLD CLUSTERSSelectivityCOPPER CLUSTERS
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