Search results for "SIZE"

showing 10 items of 2718 documents

Heterogeneous oxidation of pyrimidine and alkyl thioethers in ionic liquids over mesoporous Ti or Ti/Ge catalysts.

2004

Heterogeneous catalytic oxidation of a series of thioethers (2-thiomethylpyrimidine, 2-thiomethyl-4,6-dimethyl-pyrimidine, 2-thiobenzylpyrimidine, 2-thiobenzyl-4,6-dimethylpyrimidine, thioanisole, and n-heptyl methyl sulfide) was performed in ionic liquids by using MCM-41 and UVM-type mesoporous catalysts containing Ti, or Ti and Ge. A range of triflate, tetrafluoroborate, trifluoroacetate, lactate and bis(trifluoromethanesulfonyl)-imide-based ionic liquids were used. The oxidations were carried out by using anhydrous hydrogen peroxide or the urea-hydrogen peroxide adduct and showed that ionic liquids are very effective solvents, achieving greater reactivity and selectivity than reactions p…

chemistry.chemical_classificationTitaniumMolecular StructureChemistryGermaniumOrganic ChemistryThioanisoleInorganic chemistryGeneral ChemistrySulfidesHeterogeneous catalysisSilicon DioxidePeroxideCatalysisCatalysischemistry.chemical_compoundPyrimidinesCatalytic oxidationIonic liquidSolventsParticle SizeTrifluoromethanesulfonateOxidation-ReductionPorosityAlkylChemistry (Weinheim an der Bergstrasse, Germany)
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The Influence of (2-Chloroethyl)trimethylammoniumchloride (CCC) on Growth and Photosynthetic Metabolism of Young Wheat Plants (Triticum aestivum L.)

1984

Summary The influence of (2-chloroethyl)trimethylammoniumchloride on growth and cell metabolism of Triticum aestivum var. Kolibri was investigated. CCC was added to the nutrient solution on the 11th day of development with a final concentration of 10 −2 mol·1 −1 . It immediately stopped root growth and showed a strong inhibitory influence on the growth of the leaves. Smaller and fewer cells accounted for the reduction in final leaf size of about 40 %. The content of soluble proteins and soluble reducing sugars were significantly increased in the treated leaves. CCC also exhibited a stimulating effect on the synthesis of RubPc-ase protein and the in vitro activity of this enzyme. In contrast…

chemistry.chemical_classificationTrisPhysiologyPlant ScienceMetabolismBiologyPhotosynthesisIn vitroHorticulturechemistry.chemical_compoundEnzymeDry weightchemistryBotanyPoaceaeLeaf sizeAgronomy and Crop ScienceJournal of Plant Physiology
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Studies on the Process of Formation, Nature and Stability of Binding Sites in Molecularly Imprinted Polymers

2002

AbstractIn Molecular Imprinting the nature of the templated binding sites and the mechanism of their formation are still poorly understood. For this reason our groups are carrying out fundamental studies concerning known imprinting protocols, with the primary aim of shedding light on the role of the template in the different steps of the polymerisation, from the formation of primary chains to the build-up of the porous structure. In this paper we report our initial results concerning copolymers of methacrylic acid (MAA) and ethyleneglycol dimethacrylate (EDMA) and their formation in presence or absence of the templates 9-ethyladenine, ametryn or terbutylazine. Monitoring the monomer disappe…

chemistry.chemical_classificationchemistry.chemical_compoundMonomerMaterials scienceMethacrylic acidchemistryPolymerizationPolymer chemistrySize-exclusion chromatographyMolecularly imprinted polymerPolymerMethacrylateMolecular imprintingMRS Proceedings
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Evidence of the Gluten-Free and Casein-Free Diet in Autism Spectrum Disorders

2014

In autism spectrum disorders, many parents resort to alternative treatments and these are generally perceived as risk free. Among these, the most commonly used is the gluten-free, casein-free diet. The objective of this work was to conduct a systematic review of studies published from 1970 to date related to the gluten-free, casein-free diet in autism spectrum disorder patients. Few studies can be regarded as providing sound scientific evidence since they were blinded randomized controlled trials, and even these were based on small sample sizes, reducing their validity. We observed that the evidence on this topic is currently limited and weak. We recommend that it should be only used after…

chemistry.chemical_classificationmedicine.medical_specialtybusiness.industryCaseinsmedicine.diseaseGlutenScientific evidencelaw.inventionDiet Gluten-FreeSystematic reviewchemistryRandomized controlled trialChild Development Disorders PervasivelawSample size determinationAutism spectrum disorderPediatrics Perinatology and Child HealthmedicineHumansAutismGluten freeNeurology (clinical)businessPsychiatryDiet TherapyJournal of Child Neurology
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Multivariate correlation between13C and31P NMR spectral data on dissolved lignin and the combustion properties of kraft black liquor

1999

chemistry.chemical_compoundChromatographyChemistrySize-exclusion chromatographyLigninGeneral Materials ScienceMultiple correlationGeneral ChemistryCarbon-13 NMRSpectral dataCombustionBlack liquorKraft paperMagnetic Resonance in Chemistry
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Fast Solution Precursor Synthesis of the 2223 Phase: the Role of Lead in the Reaction Pathway

1994

ABSTRACTValuable mechanistic information, about the reaction pathway in the formation of the 2223 phase, has been obtained by the use of a solution synthesis route. The presence of lead in the starting mixture has remarkable effects on the nature and stability of the different intermediates: i) the grain size and morphology of Bi2CuO4 is severely changed, ii) calcium carbonate is partially decomposed to yield the calcium plumbate, iii) the 2201 phase results stabilized against the formation of the collapsed phase Bi17Sr16Cu7O49-δ, iv) the melting point of the intermediate 2212 is lowered by about 10 °C. All these effects, due to lead substitution, contribute to promote the formation of the …

chemistry.chemical_compoundCrystallographyCalcium carbonateMaterials sciencechemistryYield (chemistry)Phase (matter)Differential thermal analysisInorganic chemistryX-ray crystallographyMelting pointPlumbateGrain sizeMRS Proceedings
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Some Aspects of the Influence of Particle Size on Properties and Behaviour of a Dielectric Material : Example of Barium Titanate

1989

Anybody agrees with the idea that particle size plays an important role in the behaviour of a polycrystalline material but very few studies are giving precise information about this role. In this paper some experimental results are presented succintly to illustrate the importance of this physico-chemical factor. They are related to barium titanate, the main component of the dielectric material in the type II ceramic capacitors.

chemistry.chemical_compoundMaterials sciencechemistryComponent (thermodynamics)Barium titanateParticle-size distributionParticle sizeDielectricComposite materialCeramic capacitorPolycrystalline material
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Influence of synthesis conditions on the morphology of Dodecasil 1H

1993

Abstract The synthesis of Dodecasil 1H was studied in the system SiO2/1-adamantylamin/NH3/water with the objective of controlling the particle size and the morphology of the crystals. Since nucleation occurs in a very early stage of the synthesis, the heating rate to the final temperature and/or holding points during heat up have a strong influence on both parameters. Crystals smaller than 150 μm could only be obtained by the use of seed crystals, which are completely consumed in the synthesis with subsequent new nucleation. Using seed crystals, the expensive template 1-adamantylamine can be substituted with cheaper reagents such as sodium dodecyl sulfate or trimethylethylammonium bromide a…

chemistry.chemical_compoundMorphology (linguistics)chemistryChemical engineeringBromideStereochemistryReagentNucleationfood and beveragesParticle sizeSodium dodecyl sulfateSeed crystalGeneral Environmental ScienceZeolites
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Size-Dependent Spin Switching in Robust Fe-triazole@SiO2 Spin-Crossover Nanoparticles with Ultrathin Shell

2019

<p>A familly of chemically robust hybrid [Fe(Htrz)2(trz)](BF4)@SiO2nanoparticles (NPs) presenting different sizes (from ca. 90 to 28 nm) and an ultrathin silica shell (< 3 nm) have been prepared. All NPs present a characteristic abrupt spin transition with a subsequent decrease in the width of the thermal hysteresis upon reducing the NP size.<br></p>

chemistry.chemical_compoundThermal hysteresisMaterials scienceCondensed matter physicschemistrySpin crossoverSize dependentSpin transitionTriazoleShell (structure)NanoparticleSpin-½
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Kompensācija cietušajam par nodarīto kaitējumu kriminālprocesā

2015

Mūsdienās aizvien ir aktuāla morālā kaitējuma kompensācijas noteikšana kriminālprocesā, it sevišķi tāpēc, ka morālam kaitējumam nepastāv precīzi nosakāms naudas ekvivalents. Darba mērķis ir izveidot universālu, ilgspējīgu morālā kaitējuma noteikšanas koncepciju, skaidri noteikt kritērijus, kuri tiesnešiem jāņem vērā, lemjot par kaitējuma kompensācijas apmēru, turklāt izpētīt arī praktiskos jautājumus, kas saistās ar kompensācijas pieteikšanu. Pētījuma rezultātā izstrādāta ilgspējīga morālā kaitējuma koncepcija, kurā noteikti rekomendējoši, taču aptuveni kompensācijas piešķiršanas apmēri, kā arī piedāvāti vairāki Kriminālprocesa likuma grozījumi.

cietušaismorālais kaitējums (non-economic losses)kompensācijas pieteikums (compensation claim)kompensācijas apmēra noteikšanas kritēriji (criteria for determining compensation size)Juridiskā zinātnemorālā kaitējuma noteikšanas koncepcija (compensation system for personal injury)
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