Search results for "Relaxometry"
showing 10 items of 73 documents
Effects of ions on water structure: a low-field (1) H T1 NMR relaxometry approach
2014
Aqueous salt solutions play an important role in nature because of their effects on environmental biogeochemical processes and on structural properties of biomolecules. Upon dissolution, salts split in ions that are solvated. Water in hydration shells is subjected to molecular motions that can be monitored by (1) H T1 NMR relaxometry. This technique allowed the evaluation of the nature of the interactions between water and ions via variable temperature experiments. Examination of relaxometry properties of aqueous solutions at variable salt concentrations allowed acknowledgement of the role played by ions in either structuring or destructuring water aggregates. A mathematical model has been …
CHARACTERIZATION OF CHEMICAL AND PHYSICAL PROPERTIES OF BIOCHAR FOR ENERGY PURPOSES AND ENVIRONMENTAL RESTORATION
2014
Biochar production processes as well as its various applications provide numerous benefits to both environment and economy (Lehmann et al., 2006; Basu, 2010). However, understanding the physicochemical structure of this valuable product has to be improved in order to be able to obtain the aforementioned benefits and to avoid environmental costs. In this study, chicken or poultry manure (PM) was chosen as feedstock for biochar preparation. This biomass is traditionally used by farmers as an effective organic fertilizer (Chan et al., 2008). Indeed, it is considered a valuable source for readily available plant nutrients, such as N, P, K and other micronutrients (Huang et al., 2011). Notwithst…
FFC-NMR techniques for assessing the texture features of nanosponges
2021
Nanosponges (NSs), i.e. hyper cross linked polymeric materials obtained by reticulating cyclodextrin units with suitable linker units, constitute an emerging class of functional materials, due to their easy synthesis and chemical modification, and to their tunable absorption and controlled release abilities as well. NSs are supposed to possess a thick network of nanochannels in their highly disordered structure. However, their textural features (average pore size, specific surface and specific pore volume) are quite difficult to estimate, and classical evaluation methodologies (N2 absorption isotherms analyzed by BET or BJH methods, or dye absorption isotherms1) have afforded questionable r…
NMR relaxation in modern wood and treated and untreated wood from a XVI century wooden statue
2007
Longitudinal (T1) relaxation data are presented for European lime (Tilia cordata Mill) wood samples, a modern sample and two from a XVI century wooden statue, one of which samples is treated with Paraloid B72 for preservation. The 1H signals from liquid and solid are separated in the free induction decays (FID). T1 distributions are obtained by UPEN and show two resolved peaks for the liquid component of either untreated wood but a wide distribution for the liquid of the treated sample. In each case, the solid component showed a single peak, which for either untreated sample was at about the position of the longer T1 liquid peak. We compute geometric-mean times, T1-gm, 2.1 and 36 ms for the…
Interaction between armenian-clay-based ceramics and model wines
2022
The use of ceramics for the transformation or conservation of wine has existed since the origins of wine, but the impact of ceramics on wine has not received much attention.However, in contact with the wine, ceramics are generally not neutral materials and the constituent minerals of ceramics are led to dissolve. This work mainly aims to study the migration of elements from ceramics to wine.To our knowledge, this question has so not been addressed so far, at least with our chosen approach.This study required the prior characterization of the materials and the ceramics produced in the laboratory.The analyzes (XRF, XRD, and SEM/EDX) revealed that the natural material used for the manufacture …
Effects of pyrolysis conditions on the thermal transformation of chicken manure into char
2012
Biochar is a fine-grained and highly porous carbonaceous substance, arising from the pyrolitic decomposition of natural or synthetic organic materials. It is lately applied to soils to favorably affect soil physico-chemical properties, such as water and nutrient retention and cation exchange capacity (CEC). The extent of the effect of biochar on crop productivity is very variable due to the different biophysical interactions and processes that occur when it is applied to soils. Char properties are greatly influenced by both natures of feedstock and process conditions. An accurate characterization of biochar is crucial to evaluate the possibility to amend soil with such material by avoiding …
Assessing the influence of different biochar fractions on soil structure and soil water retention: laboratory investigation on a Sicilian soil
2012
Effects of ions on water structure: a low-field1HT1NMR relaxometry approach
2014
Aqueous salt solutions play an important role in nature because of their effects on environmental biogeochemical processes and on structural properties of biomolecules. Upon dissolution, salts split in ions that are solvated. Water in hydration shells is subjected to molecular motions that can be monitored by (1)H T1 NMR relaxometry. This technique allowed the evaluation of the nature of the interactions between water and ions via variable temperature experiments. Examination of relaxometry properties of aqueous solutions at variable salt concentrations allowed acknowledgement of the role played by ions in either structuring or destructuring water aggregates. A mathematical model has been a…
Zero- to Ultralow-Field NMR Spectroscopy of Small Biomolecules.
2021
Nuclear magnetic resonance (NMR) spectroscopy is a well-established analytical technique used to study chemicals and their transformations. However, high-field NMR spectroscopy necessitates advanced infrastructure, and even cryogen-free benchtop NMR spectrometers cannot be readily assembled from commercially available components. We demonstrate construction of a portable zero-field NMR spectrometer employing a commercially available magnetometer and investigate its applications in analytical chemistry. In particular, J-spectra of small representative biomolecules [13C]-formic acid, [1-13C]-glycine, [2,3-13C]-fumarate, and [1-13C]-d-glucose were acquired, and an approach relying on the prese…