Search results for " NMR relaxometry"

showing 10 items of 12 documents

Hydration and water holding properties of cross-linked lignite humic acids

2014

Abstract Lignite and lignite humic acids, which are used as soil amendments sometimes, are supposed to improve soil properties such as water holding capacity. The structure of those materials is composed of various organic molecules stabilized mostly by weak interactions. Therefore, excess of water causes only partial swelling, but most of the physical structure is destabilized. This accelerates the desiccation and hampers their application as natural hydrogel-like substances. In order to stabilize the structure of lignite humic acids and improve the water holding capacity, we applied formaldehyde cross-linking procedure based on covalent coupling of aromatic humic acids moieties. By combin…

MoistureEnvironmental remediationChemistrySettore AGR/13 - Chimica AgrariaSoil ScienceSorptioncomplex mixturesSoil conditionerlignite humic acids cross-linking hydration DSC NMR relaxometry water molecule bridgesChemical engineeringSoil watermedicineOrganic chemistryRelative humiditySwellingmedicine.symptomThermal analysis
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Water dynamics in different biochar fractions.

2014

Biochar is a carbonaceous porous material deliberately applied to soil to improve its fertility. The mechanisms through which biochar acts on fertility are still poorly understood. The effect of biochar texture size on water dynamics was investigated here in order to provide information to address future research on nutrient mobility towards plant roots as biochar is applied as soil amendment. A poplar biochar has been stainless steel fractionated in three different textured fractions (1.0-2.0 mm, 0.3-1.0 mm and0.3 mm, respectively). Water-saturated fractions were analyzed by fast field cycling (FFC) NMR relaxometry. Results proved that 3D exchange between bound and bulk water predominantly…

Magnetic Resonance SpectroscopyDynamicChemistry (all)Texture sizeWaterChemical FractionationMicro-CT imagingDiffusionBiochar; Dynamics; FFC NMR relaxometry; Micro-CT imaging; Micro-tomography; Texture size; Water; Chemistry (all); Materials Science (all)BiocharMicro-tomographySoilPopulusCharcoalMaterials Science (all)FertilizersTomography X-Ray ComputedPorosityFFC NMR relaxometryMagnetic resonance in chemistry : MRC
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Applications of fast field cycling NMR relaxometry

2021

Abstract Fast field cycling (FFC) NMR relaxometry is emerging as a powerful tool to investigate physical chemistry properties of many systems in a number of different scientific fields. As an example, it is used to investigate environmental issues such as soil erosion, water, and nutrient dynamics in environmentally relevant porous systems, to discriminate among different kinds of foodstuff in order to understand possible source of adulteration and fraud, to evaluate the properties of new materials, and much more. In the present study, an overview about the possible applications of FFC NMR relaxometry is given. The paper is not intended to be exhaustive. Rather, it is thought to provide an …

Food scienceSoil scienceWater scienceRelaxometryField cyclingComputer scienceSettore AGR/13 - Chimica AgrariaNew materialsSediment scienceBiochemical engineeringMaterial scienceFFC NMR relaxometry
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Integrated techniques to study sedimentary rocks from Sicily used in Cultural Heritage

2005

Sedimentary rock NMR relaxometry XRF
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Sviluppo e Applicazioni di nuovi materiali per la dosimetria delle radiazioni ionizzanti

The Research Activities carried out during the Three-year International PhD Course in Applied Physics of the candidate Salvatore Gallo had two main topics related to dosimetry of ionizing radiations (IR): the analysis of 3D gel dosimeters and the analysis of solid state dosimeters through electron spin resonance. Both these activities are focused on a careful study of new materials for the IR Dosimetry, both in terms of physical characterization of these new materials and of the optimization of readout methods for dosimetric measurements. The study performed through various techniques such as UV-Vis absorption spectroscopy, NMR Relaxometry, Magnetic Resonance Imaging (MRI) and Electron Spin…

Settore FIS/01 - Fisica SperimentaleDosimetry ESR Spectroscopy NMR Relaxometry MRI Fricke gel dosimetry Xylenol Orange Irganox 1076 RadiotherapySettore FIS/07 - Fisica Applicata(Beni Culturali Ambientali Biol.e Medicin)
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Adsorption of dissolved organic matter on clay minerals as assessed by infra-red, CPMAS 13C NMR spectroscopy and low field T1 NMR relaxometry

2011

Abstract Dissolved organic matter (DOM) is a very important environmental constituent due to its role in controlling factors for soil formation, mineral weathering and pollutant transport in the environment. Prediction of DOM physical–chemical properties is achieved by studying its chemical structure and spatial conformation. In the present study, dissolved organic matter extracted from compost obtained from the organic fraction of urban wastes (DOM-P) has been analysed by FT-IR, CPMAS 13C NMR spectroscopy and 1H T1 NMR relaxometry with fast field cycling (FFC) setup. While the first two spectroscopic techniques revealed the chemical changes of dissolved organic matter after adsorption eith…

T1 NMR relaxometryRelaxometryMineralCompostDOM; CPMAS 13C NMR; T1 NMR relaxometrySettore AGR/13 - Chimica Agrariaengineering.materialFT-IRchemistry.chemical_compoundMontmorilloniteAdsorptionchemistryGeochemistry and PetrologyEnvironmental chemistryDissolved organic carbonCPMAS 13C NMRengineeringOrganic chemistryKaoliniteDissolved organic matterRelaxometryClay mineralsDOMOrganic Geochemistry
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Combined proton NMR wideline and NMR relaxometry to study SOM-water interactions of cation-treated soils

2013

Abstract Focusing on the idea that multivalent cations affect SOM matrix and surface, we treated peat and soil samples by solutions of NaCl, CaCl2 or AlCl3. Water binding was characterized with low field 1H-NMR-relaxometry (20 MHz) and 1H wideline NMR spectroscopy (400 MHz) and compared to contact angles. From 1H wideline, we distinguished mobile water and water involved in water molecule bridges (WaMB). Large part of cation bridges (CaB) between SOM functional groups are associated with WaMB. Unexpectedly, 1H NMRrelaxometry relaxation rates suggest that cross-linking in the Al-containing peat is not stronger than that by Ca. The relation between percentage of mobile water and WaMB water in…

Dewey Decimal Classification::500 | Naturwissenschaften::550 | GeowissenschaftenDewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften BiologieDewey Decimal Classification::600 | Technik::630 | Landwirtschaft VeterinärmedizinAnalytical chemistrySoil organic matter (SOM); Low field 1H NMR relaxometry; 1H wideline NMR spectroscopy; Contact angle; Cation bridges; Water molecule bridges.TA Engineering (General). Civil engineering (General)soil organic matter (som)Low field H-1 NMR relaxometrystateContact angleNuclear magnetic resonancewater molecule bridgesddc:550ddc:630natural organic-mattercontact angleWater Science and TechnologyFluid Flow and Transfer Processeschemistry.chemical_classificationhumic substancesWater molecule bridges.Nuclear magnetic resonance spectroscopycation bridgesCation bridgemultiexponential decay datanuclear-magnetic-resonanceH-1 wideline NMR spectroscopyProton NMRWater bindingTC1-978Relaxometryuniform-penalty inversionlow field 1h nmr relaxometrySettore AGR/13 - Chimica AgrariaContext (language use)1h wideline nmr spectroscopyforest soilsCation bridgesddc:570sandy soilOrganic mattercontact-angleContact angleSoil organic matter (SOM)repellencyMechanical EngineeringHydraulic engineeringchemistrySoil waterWater molecule bridgesJournal of Hydrology and Hydromechanics
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Cooking influence on physico-chemical fruit characteristics of eggplant (Solanum melongena L.)

2016

Physico-chemical traits of three eggplant genotypes ("Tunisina", "Buia" and "L 305") were evaluated before and after two cooking treatments (grilling and boiling). Different genotypes revealed different changes after cooking, with "Tunisina" showing a better retention of phytochemicals with respect to other two genotypes. The main physical phenomena were water loss during grilling, and dry matter loss after boiling. Chlorogenic acid, the main phenolic in eggplant, resulted higher in grilled samples, while delphinidin glycosides resulted more retained in boiled samples. Glycoalkaloids, thiols and biogenic amines were generally stable, while 5-hydroxy-methyl-furfural was found only in grilled…

AntioxidantMagnetic Resonance Spectroscopymedicine.medical_treatmentPhytochemicalsSettore AGR/13 - Chimica AgrariaFood chemistryEggplantPhytochemical01 natural sciencesAntioxidantsAnalytical Chemistrychemistry.chemical_compound0404 agricultural biotechnologyChlorogenic acidPhenolsBotanymedicineDry matterPhenolsFood scienceCookingSolanum melongenaAntioxidants; Cooking; Eggplant; NMR relaxometry; Phenols; Antioxidants; Chlorogenic Acid; Fruit; Magnetic Resonance Spectroscopy; Phenols; Phytochemicals; Solanum melongena; Food Science; Analytical Chemistry; Medicine (all)chemistry.chemical_classificationbiologyPhenolMedicine (all)010401 analytical chemistryfood and beveragesGlycoside04 agricultural and veterinary sciencesGeneral Medicinebiology.organism_classification040401 food science0104 chemical scienceschemistryFruitNMR relaxometryDelphinidinSolanumAntioxidantChlorogenic AcidFood Science
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Fast field cycling NMR relaxometry as a tool to monitor Parmigiano Reggiano cheese ripening.

2020

Abstract It is widely recognized that the longer the ageing, the more valuable Parmigiano Reggiano (PR) cheese becomes, due to the improvement of its sensorial and nutritional properties. Up to now, the evaluation of PR properties has been performed on samples mainly aged up to 40 months. For this reason, this study was aimed at collecting information about the chemical-physical characteristics of PR cheeses after ageing at 24, 48 and 84 months. The basic analyses on water amount, protein content and volatile organic compounds (VOC) revealed that PR ageing is associated to the decomposition of the organic components into smaller units. This drives water molecules closer to the aforementione…

RelaxometryMagnetic Resonance SpectroscopyWater activity030309 nutrition & dieteticsCheese ripeningMaturation index03 medical and health sciences0404 agricultural biotechnologyCheeseBound waterMoleculeFood scienceFatty acids0303 health sciencesVolatile Organic CompoundsParmigiano Reggiano cheeseChemistryRipening04 agricultural and veterinary sciences040401 food scienceDecompositionMagnetic Resonance ImagingAgeingVolatile compoundsDegradation (geology)Fast field cycling NMR relaxometryFood AnalysisWater activityFood ScienceFood research international (Ottawa, Ont.)
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Thermal transformation of micro-crystalline cellulose in phosphoric acid

2011

Use of crude oil derivatives such as diesel and gasoline is becoming unsuitable due to their detriment to environment and to the increasing worldwide energy demand which is driving crude oil reservoirs towards exhaustion. Replacement of diesel and gasoline with biofuels (i.e. biodiesel and bioethanol, respectively) is very desirable. In fact, biofuels are not only environmentally sustainable, but also potentially inexhaustible due to the large amounts of waste biomasses from which they can be retrieved. In the present study, a model compound (micro-crystalline cellulose) was dissolved in phosphoric acid and converted at 80 °C to glucose, thereby providing the possible substrate for fermenta…

Biodiesel13C NMRMaterials sciencePolymers and PlasticsSettore AGR/13 - Chimica AgrariaBioethanol1H T1 NMR relaxometryPulp and paper industrycomplex mixtureschemistry.chemical_compoundDiesel fuelCellulose degradationchemistryBiochemistryBiofuelBiofuelLevulinic acidFermentationGasolineCellulosePhosphoric acid
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