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Purpose Single‐sided 1H‐NMR is proposed for the estimation of morphological parameters of trabecular bone, and potentially the detection of pathophysiological alterations of bone structure. In this study, a new methodology was used to estimate such parameters without using an external reference signal, and to study intratrabecular and intertrabecular porosities, with a view to eventually scanning patients. Methods Animal trabecular bone samples were analyzed by a single‐sided device. The Carr‐Purcell‐Meiboom‐Gill sequence of 1H nuclei of fluids, including marrow, confined inside the bone, was analyzed by quasi‐continuous T2 distributions and separated into two 1H pools: short and long T2 components. The NMR parameters were estimated using models of trabecular bone structure, and compared with the corresponding micro‐CT. Results Without any further assumptions, the internal reference parameter (short T2 signal intensity fraction) enabled prediction of the micro‐CT parameters BV/TV (volume of the trabeculae/total sample volume) and BS/TV (external surface of the trabeculae/total sample volume) with linear correlation coefficient >0.80. The assignment of the two pools to intratrabecular and intertrabecular components yielded an estimate of average intratrabecular porosity (33 ± 5)%. Using the proposed models, the NMR‐estimated BV/TV and BS/TV were found to be linearly related to the corresponding micro‐CT values with high correlation (>0.90 for BV/TV; >0.80 for BS/TV) and agreement coefficients. Conclusion Low‐field, low‐cost portable devices that rely on intrinsic magnetic field gradients and do not use ionizing radiation are viable tools for in vitro preclinical studies of pathophysiological structural alterations of trabecular bone.

Nuclear Magnetic Resonance (NMR) is a well-suited methodology to study bone composition and structural properties. This is because the NMR parameters, such as the T2 relaxation time, are sensitive to the chemical and physical environment of the 1H nuclei. Although magnetic resonance imaging (MRI) allows bone structure assessment in vivo, its cost limits the suitability of conventional MRI for routine bone screening. With difficulty accessing clinically suitable exams, the diagnosis of bone diseases, such as osteoporosis, and the associated fracture risk estimation is based on the assessment of bone mineral density (BMD), obtained by the dual-energy X-ray absorptiometry (DXA). However, integrating the information about the structure of the bone with the bone mineral density has been shown to improve fracture risk estimation related to osteoporosis. Portable NMR, based on low-field single-sided NMR devices, is a promising and appealing approach to assess NMR properties of biological tissues with the aim of medical applications. Since these scanners detect the signal from a sensitive volume external to the magnet, they can be used to perform NMR measurement without the need to fit a sample inside a bore of a magnet, allowing, in principle, in vivo application. Techniques based on NMR single-sided devices have the potential to provide a high impact on the clinical routine because of low purchasing and running costs and low maintenance of such scanners. In this review, the development of new methodologies to investigate structural properties of trabecular bone exploiting single-sided NMR devices is reviewed, and current limitations and future perspectives are discussed.

This work is focused on the effects of drying/re-saturation cycles on the structure and components of White Portland Cement (WPC) samples. In particular, WPC of 0.5 water-to-cement ratio was studied by 1H Nuclear Magnetic Resonance (NMR) Relaxometry. A number of NMR sequences and different data processing methods were applied. Short (14 days of re-saturation) and long (6 months for the whole cycle) sorption cycles were investigated, using two drying methods: oven drying and drying under controlled relative humidity. The evolution during drying/re-saturation processes of interlayer space, gel pores, and bigger pores was followed by both the transverse relaxation times and the intensities of the nuclear magnetization. As a result of drying, reversible and irreversible changes in the pore structure, especially concerning the smaller porosity (interlayer and gel pores), were seen. Likewise, 1H signals in the crystalline phases of the cement were investigated by the standard Quadrature Echo method and by a more informative analysis based and a proper acquisition and processing of the longitudinal relaxation data. This analysis allowed the signal separation of 1H nuclei with higher and lower mobility (“solid” components). The NMR signal from this last component was analyzed on the basis of the Pake-Doublet theory in the time domain and two components were clearly detected, and assigned to 1H nuclei of crystalline water in Ettringite and OH groups in Portlandite. Reversible changes of the solid components of the cement samples were observed. This is a new method to deeply investigate the changes of solid components during sorption cycles.

Summary This paper presents preliminary results of a new T2Well version, coupled with modified ECO2M equation of state, able to simulate three-phase flow in the wellbore with the coexistence of liquid and gaseous CO2, with the final aim to be able to detect possible operational problems caused by phase changes during transient flow periods.

Paintings on canvas are complex structures created by superimposing layers of different composition. Investigations on the structure of these artworks can provide essential information on their state of conservation, pictorial technique, possible overpaintings, and in planning a proper conservation plan. Standard methods of investigation consist in sampling a limited number of fragments for stratigraphic analyses. Despite the recognized validity of these methods, they are affected by evident limitations. Nuclear magnetic resonance (NMR) profiling, often named NMR stratigraphy, is an NMR relaxometry technique applied by single-sided portable devices developed to overcome the disadvantages of microinvasive stratigraphic analyses. The potential of this approach on artworks, including wall paintings and a few examples of painted canvas, is described in the literature. In this study, NMR profiles of painting on canvas were examined by analyzing transverse relaxation time data by T2 quasi-continuous distributions and the results compared with standard stratigraphic cross-sections analysis. Combining signal intensity and T2 quasi-continuous distributions, the identification of textile, preparatory, and paint layers was enhanced. The diction "NMR stratigraphy" for these inhomogeneous layered artworks is also discussed. Indeed, unlike the stratigraphic cross-sections, NMR profiles provide information on a volume (flat slice), rather than on a surface, and the collected signal can derive from nonuniform and partially overlapping layers. This study paves the way for extensive investigations on relaxation time quasi-continuous distributions in various binder/pigment mixtures in order to improve the reliability of NMR profile as an innovative, non-invasive, and nondestructive method for analyzing paintings on canvas.

Geologists and Reservoir Engineers routinely use time-domain nuclear magnetic resonance (NMR) to learn about the porous structure of rocks that hold underground fluids. In particular, two-dimensional NMR (2DNMR) technique is now gaining importance in a wide variety of applications. Crucial issue in 2DNMR analysis are the speed, robustness and accuracy of the data inversion process. This paper proposes a multi-penalty method with locally adapted regularization parameters for fast and accurate inversion of 2DNMR data. The method solves an unconstrained optimization problem whose objective function contains a data-fitting term, a single L1 penalty parameter and a multiple parameter L2 penalty. We propose an adaptation of the Fast Iterative Shrinkage and Thresholding (FISTA) method to solve the multi-penalty minimization problem, and an automatic procedure to compute all the penalty parameters. This procedure generalizes the Uniform Penalty principle introduced in [Bortolotti et al., Inverse Problems, 33(1), 2016]. The proposed approach allows us to obtain accurate 2D relaxation time distributions while keeping short the computation time. Results of numerical experiments on synthetic and real data prove that the proposed method is efficient and effective in reconstructing the peaks and the flat regions that usually characterize 2DNMR relaxation time distributions.

The conservation of historical buildings and outdoor cultural assets is of great value for the humankind. In this context, consolidation treatments represent a fundamental procedure to assure the survival of deteriorated cultural artefacts. For porous materials characterized by a wide distribution of pore sizes, adequate consolidation treatments require a product with a sufficient penetration depth and homogeneous distribution inside the unconsolidated substrate. Since water is one of the main deterioration agents of stone, the wettability of rock should also be minimized. A non-invasive and non-destructive technique, able to localize the consolidation agent and the water uptake, is needed to evaluate the efficiency of the treatments. NMR techniques are good candidates to satisfy this requirement. The present study aims at investigating the efficiency of two commercial consolidants, i.e. ethyl silicate and nano-silica, and a new formulated mixture of a fluoroelastomer and nano-silica by NMR relaxometry and MRI. The tested compounds showed adequate characteristics to be used as consolidating agents for highly porous carbonate rocks like limestone. All the products, in fact, penetrated uniformly and homogeneously into the porous structure, and preserved the connectivity of the stone matrix, as demonstrated by T 2 - T 2 relaxation exchange experiments. Moreover, the hydrophilic behavior of commercial consolidants could be reduced, when the newly formulated agent was used. This study shows how the combination of different NMR techniques, applied in the time domain and with spatial resolution, is a powerful approach for evaluating the consolidation efficiency.

A crucial aspect of geothermal reservoir engineering is the performance and interpretation of field tests, such as production tests, flowing temperature and pressure logs - both during injection and production, and down-hole pressure transient recording. Such tests are of great importance in order to evaluate the reservoir properties and to predict wells production capacity. However, production tests duration is often limited by environmental constraints related to the disposal of brines, and the running of downhole measurements is constrained by safety and cost considerations related to the use of expensive tools in high temperature high productive wells. From this point of view, the capability to simulate the whole production tests can be extremely useful to improve the data interpretation and reduce the impact of lacking field data. In particular, the coupled simulation of transient fluid flow within the wellbore and the reservoir with the matching of output production curve, flowing logs, and downhole pressure transients, should result in a more reliable evaluation of reservoir properties. This can be done using T2Well, a coupled wellbore-reservoir numerical simulator, with proper equation of state (EOS) modules. EWASG is an EOS module for high enthalpy geothermal fluids consisting of mixtures of water, salts and a non-condensable gas (NCG). We have recently plugged it into T2Well and also improved the analytical computation of heat exchange between the well and the surrounding formations at early time, which may be important for reproducing the transient results of production tests. The resulted wellbore-reservoir simulator, T2Well-EWASG, is capable to simulate high enthalpy geothermal wells. We validated T2Well-EWASG against flowing pressure and temperature logs taken from published literature.

Purpose Reduced bone strength is associated with a loss of bone mass, usually evaluated by dual-energy X-ray absorptiometry, although it is known that the bone microstructure also affects the bone strength. Here, a method is proposed to measure (in laboratory) the bone volume–to–total volume ratio by single-sided NMR scanners, which is related to the microstructure of the trabecular bone. Methods Three single-sided scanners were used on animal bone samples. These low-field, mobile, low-cost devices are able to detect the NMR signal, regardless of the sample sizes, without the use of ionizing radiations, with the further advantage of signal localization offered by their intrinsic magnetic field gradients. Results The performance of the different single-sided scanners have been discussed. The results have been compared with bone volume–to–total volume ratio by micro CT and MRI, obtaining consistent values. Conclusions Our results demonstrate the feasibility of the method for laboratory analyses, which are useful for measurements like porosity on bone specimens. This can be considered as the first step to develop an NMR method based on the use of a mobile single-sided device, for the diagnosis of osteoporosis, through the acquisition of the signal from the appendicular skeleton, allowing for low-cost, wide screening campaigns. Magn Reson Med 79:501–510, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Pathline or streamline computation is used today to improve the understanding of fluid flow behavior in groundwater modelling. In particular, pathline computation on unstructured grids requires an accurate velocity interpolation method when the flow velocity field is given by numerical simulators only at the faces of the grid blocks; as for example in the case of the Integral Finite Difference method is used for spatial discretization. In the case of 3D Voronoi unstructured grids, a corner velocity interpolation (CVI) method allows continuous velocity field interpolation while preserving the mass conservation principle. We have developed a computer code, named TOUGH2Path, able to compute the velocity field based on the CVI method and generalized barycentric coordinates for 3D Voronoi polytope grid blocks tailored for the TOUGH family of codes. Results for the classical quarter five spot problem show that the coded algorithm correctly reproduces the pathlines computed with semi-analytical methods.

The analysis of Nuclear Magnetic Resonance (NMR) relaxation of 1H nuclei gives fundamental information about the structure of different types of porous media via the determination of 1-dimensional and 2-dimensional (2D) distributions of the typical NMR parameters (longitudinal T1and transverse T2relaxation times). Despite the great amount of literature available on this topic, only a few open source software are available, usually after a direct request to the authors. This work aims to stimulate the comparison of different approaches by making our open source inversion Matlab Package (Upen2DTool) available, to encourage its application and extension to the various 2D NMR problems. The solution algorithm applies the Uniform PENalty principle and automatically computes locally adapted regularization parameters and approximate solutions. Moreover a Windows binary code is available for testing for non-Matlab users. Keywords: 2D NMR data inversion, Uniform penalty, Adaptive regularization, SVD filtering

Polymer modified bitumen (PMB) is used extensively in thin asphalt surfacing and seals in order to improve specific performances. However, the performances of PMB are not easy to demonstrate with the conventional methods, such as penetration test, softening point etc. In order to a better evaluation, different characterization methods are needed rather then ordinary empirical rheological tests. This work deals with the characterization of linear copolymer styrene–butadiene–styrene (SBS) and SBS + polyphosphoric acid (PPA) modified bitumen by using conventional as well as advanced methods on bitumens at different ageing steps and temperature. Fundamental rheological tests, based on a state of the art dynamic shear rheometer in the temperature range from −30 °C to +160 °C and advanced 1 H magnetic resonance relaxometry analysis to evaluate the effect of modifiers on the bitumen structure, were used. Moreover, morphological analysis by scanning electron microscope (SEM) was performed on neat and modified bitumen and the effect of the filler addition on the supra-molecular organization of the bituminous binder was also investigated.

TMGAS, an equation of state module of TOUGH2 V.2.0 reservoir simulator, was used to model the migration of CO2, H2S, and CH4 in a deep sedimentary formation. The scope is the improvement of the description of non-condensable gas (NCG) migration within modeling studies of sedimentary basins’ evolution. Different scenarios have been simulated with NCG migration taking place in a large sedimentary formation discretized with a full 3D Voronoi approach by using specifically improved versions of the pre- and post-processing tools for TOUGH2 developed at the University of Bologna. Simulated reference scenarios are related to the migration of CO2, H2S, and CH4 generated at constant rate for 1 × 106 years in a fresh water aquifer. Additional scenarios are simulated with NCG migration taking place in the same formation but saturated with brine. The effects of pressure-temperature-composition (PTX) conditions on thermodynamic equilibria, phase composition, phase thermo-physical properties and, consequently, on the migration features of different NCGs are modeled and discussed. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd

Summary Stabilization of organic matter (OM) is an important topic in soil science, but it is not yet completely understood. Recent interest in the recovery of poor or damaged soil with the addition of OM from waste such as paper mill sludge has led to further research on this topic. Research on the association of OM with soil minerals is difficult; therefore, most of the experimental studies published have been carried out on natural (not treated) or artificial soil. In this paper, we describe the use of both 1H nuclear magnetic resonance relaxometry in the time domain (TD-MRR) and N2 adsorption–desorption techniques to characterize samples of soil taken from a hillside treated with paper mill sludge. We have shown that although both techniques are sensitive to different, but to some extent complementary, scales of pore sizes, they can highlight the clogging effect of OM on soil pores (in a range of pores sizes from a few nm to several µm). The relations with total organic carbon were similar for the bound water porosity evaluated by TD-MRR and the specific surface area determined by N2 adsorption–desorption. This new approach that uses both TD-MRR and N2 adsorption–desorption also suggests that OM is well protected in small pores (≤ 2 µm), especially when there is preferential association with minerals, for example with kaolin clay and carbonates. Highlights Characterization of the porosity of soil sampled from a hillside treated with organic waste. The combined use of 1H nuclear magnetic resonance relaxometry and N2 adsorption-desorption techniques. There is a clogging effect of organic matter on soil pores from a few nm to several µm. Both techniques can be used to add information on potential TOC stabilization.

The software TOUGH2Viewer 2.0, originally available since 2012, is an enhanced visualization software specifically designed to visualize the results of TOUGH simulations performed using structured and fully unstructured 3D Voronoi grids. 3D Voronoi grids permit a great degree of flexibility when accurate numerical simulations are required. The TOUGH family of simulators represents a set of software well-known worldwide for numerical modeling and simulation for coupled transport of water, vapor, non-condensable gas and heat in porous and fractured media. Nevertheless, TOUGH has no native enhanced pre- and post-processing tools, and several pre- and post-processing tools have been developed. Using TOUGH2Viewer the users can interactively navigate the model, a 3-dimensional virtual environment, by means of a Graphical User Interface (GUI). This new version of TOUGH2viewer allows the editing of numerical models by dedicated GUIs, adding pre-processing capabilities.

In this paper we present an improvement of the 2DUPEN algorithm (I2DUPEN) obtained by applying data windowing and Singular Value Decomposition (SVD) filtering. The presented I2DUPEN method solves a regularized weighted least squares problem where the weights are related to the statistics of the data. The SVD filtering is applied to reduce the problem size. The preliminary results on real 2D Nuclear Magnetic Resonance data show the potentiality of this strategy to improve the performance of the algorithm preserving reconstructions of good quality. Just as the original 2DUPEN algorithm, I2DUPEN can be used on a wide range of NMR data obtained from different kinds of samples, from multi-scale length porous materials to biological samples.

The exploitation potential of shallow geothermal energy is usually defined in terms of site-specific ground thermal characteristics. While true, this assumption limits the complexity of the analysis, since feasibility studies involve many other components that must be taken into account when calculating the effective market viability of a geothermal technology or the economic value of a shallow geothermal project. In addition, the results of a feasibility study are not simply the sum of the various factors since some components may be conflicting while others will be of a qualitative nature only. Different approaches are therefore needed to evaluate the suitability of an area for shallow geothermal installation. This paper introduces a new GIS platform-based multicriteria decision analysis method aimed at comparing as many different shallow geothermal relevant factors as possible. Using the Analytic Hierarchic Process Tool, a geolocalized Suitability Index was obtained for a specific technological case: the integrated technologies developed within the GEOTeCH Project. A suitability map for the technologies in question was drawn up for Europe.

There is growing interest in construction field issues related to environmental protection, energy saving and raw materials. Therefore, the interest in recycling waste materials to produce new construction ones is constantly increasing. This study proposes a new methodology to produce lightweight aggregates (LWAs) by alkali-activation of two different waste powders: a digested spent bentonite clay and a basalt powder. Metakaolin, as secondary precursor, was added to the mixtures according to mix-design proportions, to improve the mechanical properties of the final materials, while a specific activators mix of Sodium Silicate and Sodium Hydroxide enabled the alkali-activation. The expansion process, on the other hand, was obtained using Peroxide within the liquid mix. The experimental LWAs were analyzed and tested in compliance with the EN 13055-1 standard. A more in-depth analysis on LWAs&rsquo, air voids content and porosity was also carried out by the means of Mercury Intrusion Porosimetry and Nuclear Magnetic Resonance. The results were compared with those obtained from commercial Lightweight Expanded Clay Aggregate, which represents one of the most common LWAs in the construction field. According to the presented preliminary results, the use of alkali-activated waste powders seems to be a suitable solution for the production of eco-friendly LWAs by allowing the recycling of waste materials and energy saving for their production.

The kinetics of cement hydration has been studied by 1 H-NMR, through the analysis of the Free Induction Decay (FID) combined with quasi-continuous T 1 relaxation time distributions analysis, operating a sort of 2D T 1 – T 2 correlation analysis on a somewhat more physical than mathematical basis. The analysis allowed us to distinguish two solid components, SS (Solid-Short) with T 1 of a few milliseconds and SL (Solid-Long) with T 1 of the order of a second, ascribable to 1 H of anisotropically bound groups in the C–S–H gel, and to 1 H nuclei of the Portlandite crystals and possibly to crystal water in Ettringite crystals, respectively. A liquid-like component LS (Liquid-Short) with very short T 2 (∼80 μs) and T 1 a few milliseconds, both quite stable during hydration, was isolated and interpreted as water confined in the inter-layer spaces of the gel. Amounts of LS and SS increase together steadily during hydration, and these, divided by LL (Liquid-Long, the signal from the water in the pores), are proportional to 1/ T 1 for LL, confirming a surface relaxation effect for LL.

TOUGH2 is an integral finite differences numerical simulator for non-isothermal multiphase flow in fractured porous media, which can manage complex spatial discretizations. Numerical simulation accuracy is affected, among other things, by grid resolution. Increasing the grid resolution requires computational and operating costs depending on the number of nodes and variables processed. The complexity of the management of the model increases when unstructured grids and local refinement are used. In order to improve the management and optimize the activities to update the model, an open source pre-processor has been developed using the open source codes GRASS GIS, SQLite and AMESH. Operations such as domain discretization, rock type assignment and mesh file generation have been automatized. Graphical interfaces allow for a user-friendly utilization. Operating errors and time required by pre-processing activities to generate and update locally refined unstructured grids have been reduced. Productivity in numerical modeling has been substantially increased. A novel approach to generate TOUGH2 input file through GIS is presented.TOUGH2GIS automatically creates locally refined unstructured 3D grids.Rock types attribution to grid blocks is automatically and efficiently performed.Seamless integration into an available open-source GIS package.An application to a sample dataset shows method feasibility.

none 8 As is known, a full three-dimensional (3D) unstructured grid permits a great degree of flexibility when performing accurate numerical reservoir simulations. However, when the Integral Finite Difference Method (IFDM) is used for spatial discretization, constraints (arising from the required orthogonality between the segment connecting the blocks nodes and the interface area between blocks) pose difficulties in the creation of grids with irregular shaped blocks. The full 3D Voronoi approach guarantees the respect of IFDM constraints and allows generation of grids conforming to geological formations and structural objects and at the same time higher grid resolution in volumes of interest. In this work, we present dedicated pre- and post-processing gridding software tools for the TOUGH family of numerical reservoir simulators, developed by the Geothermal Research Group of the DICAM Department, University of Bologna. VORO2MESH is a new software coded in C++, based on the voro++ library, allowing computation of the 3D Voronoi tessellation for a given domain and the creation of a ready to use TOUGH2 MESH file. If a set of geological surfaces is available, the software can directly generate the set of Voronoi seed points used for tessellation. In order to reduce the number of connections and so to decrease computation time, VORO2MESH can produce a mixed grid with regular blocks (orthogonal prisms) and irregular blocks (polyhedron Voronoi blocks) at the point of contact between different geological formations. In order to visualize 3D Voronoi grids together with the results of numerical simulations, the functionality of the TOUGH2Viewer post-processor has been extended. We describe an application of VORO2MESH and TOUGH2Viewer to validate the two tools. The case study deals with the simulation of the migration of gases in deep layered sedimentary formations at basin scale using TOUGH2-TMGAS. A comparison between the simulation performances of unstructured and structured grids is presented. Bonduà, Stefano; Battistelli, Alfredo; Berry, Paolo; Bortolotti, Villiam; Consonni, Alberto; Cormio, Carlo; Geloni, Claudio; Vasini, Ester Maria Bonduà, Stefano; Battistelli, Alfredo; Berry, Paolo; Bortolotti, Villiam; Consonni, Alberto; Cormio, Carlo; Geloni, Claudio; Vasini, Ester Maria

Scientists applying magnetic resonance techniques to cultural heritage are now a quite vast and international community, even if these applications are not yet well known outside this community. Not only laboratory experiments but also measurements in the field are now possible, with the use of portable nuclear magnetic resonance (NMR) instruments that enable non-invasive and non-destructive studies on items of any size, of high artistic and historical value as well as diagnosis of their conservation state. The situation was completely different in the second half of the 1990s when our group started working on applications of NMR to cultural heritage, by combining the knowledge of NMR for fluids in porous media at the University of Bologna, with the skilfulness of the chemists for cultural heritage of CNR and University of Florence, and Safeguarding Cultural Heritage Department of Aosta. Since then, our interest has been mainly devoted to develop methods to study the structure of pore space and their changes as a result of the decay, as well as to evaluate performance of the protective and conservative treatments of porous materials like stone, ceramic, cements and wood. In this paper, we will review the pathway that led us from the first tentative experiments, in the second half of the 1990s to the current work on these topics.

Fast-field-cycling nuclear magnetic resonance (FFC-NMR) is a powerful technique for non-destructively probing the properties of fluids contained within the pores of porous materials. FFC-NMR measures the spin&ndash, lattice relaxation rate R 1 ( f ) as a function of NMR frequency f over the kHz to MHz range. The shape and magnitude of the R 1 ( f ) dispersion curve is exquisitely sensitive to the relative motion of pairs of spins over time scales of picoseconds to microseconds. To extract information on the nano-scale dynamics of spins, it is necessary to identify a model that describes the relative motion of pairs of spins, to translate the model dynamics to a prediction of R 1 ( f ) and then to fit to the experimental dispersion. The principles underpinning one such model, the 3 &tau, model, are described here. We present a new fitting package using the 3 &tau, model, called 3TM, that allows users to achieve excellent fits to experimental relaxation rates over the full frequency range to yield five material properties and much additional derived information. 3TM is demonstrated on historic data for mortar and plaster paste samples.

Reduced bone strength is associated with a loss of bone mass, usually evaluated by dual-energy X-ray absorptiometry, although it is known that the bone microstructure also affects the bone strength. Here, a method is proposed to measure (in laboratory) the bone volume-to-total volume ratio by single-sided NMR scanners, which is related to the microstructure of the trabecular bone.Three single-sided scanners were used on animal bone samples. These low-field, mobile, low-cost devices are able to detect the NMR signal, regardless of the sample sizes, without the use of ionizing radiations, with the further advantage of signal localization offered by their intrinsic magnetic field gradients.The performance of the different single-sided scanners have been discussed. The results have been compared with bone volume-to-total volume ratio by micro CT and MRI, obtaining consistent values.Our results demonstrate the feasibility of the method for laboratory analyses, which are useful for measurements like porosity on bone specimens. This can be considered as the first step to develop an NMR method based on the use of a mobile single-sided device, for the diagnosis of osteoporosis, through the acquisition of the signal from the appendicular skeleton, allowing for low-cost, wide screening campaigns. Magn Reson Med 79:501-510, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

How to estimate the risk of the occurrence of non-hydrocarbon components (nonHC) such as carbon dioxide (CO2), hydrogen sulfide (H2S) or nitrogen (N2), is one of the main issues in the field of petroleum exploration. Numerical models can provide valuable tools to predict the occurrence and distribution of such components. Different approaches exists to this end, starting from the simplest ones, relying onto geometrical considerations, up to those based on a fully physical description of the migration and accumulation processes.In this work, a procedure for efficient coupling of petroleum system analysis withmultiphase Darcy flow simulations is developed to obtain 3D time dependent representation of the migration paths and accumulation volumes of nonHC at basin scale on a geological timescale. We focus on the tests carried out to prove that is technically feasible to run simulations of very deep geological formations (high P, T, salinity) even if considering a very detailed picture of the transport phenomena (buoyant, viscous and capillary forces). The challenge is to find the right compromise between the needs to honor fine-scale hydrostratigraphic details of the structure and the size of the numerical model in its discretized form.

This work aimed to study pulsed electric fields (PEF) effect on the water distribution of freeze-dried apple. Apple (var. Cripps Pink) was treated in 15% trehalose and 1% ascorbic acid solution (388μS/cm) at 3Hz and various electric field strengths 0.3; 0.6; 0.9 and 1.2kVcm−1 for 5, 10 or 15 pulses. The samples were frozen at −45°C and freeze-dried. The analyses were performed after rehydration. Differential Scanning Calorimetry (DSC) and Nuclear Magnetic Resonance in the domain of time (TD-NMR) were performed to assess thermal properties of freezable water and water distribution in apple tissue, respectively. PEF changed the integrity and continuity of the cell structure shown by the water redistribution between different compartments. The water in vacuoles and extracellular spaces had higher TD-NMR relaxation times as water molecules can diffuse in larger volumes before relaxing, even if the overall solutes concentration in the tissue increases.

Time-Domain Nuclear Magnetic Resonance (TD-NMR) of 1 H nuclei is used to monitor the maturation up to 30 days of three different endodontic cement pastes. The “Solid–liquid” separation of the NMR signals and quasi-continuous distributions of relaxation times allow one to follow the formation of chemical compounds and the build-up of the nano- and subnano-structured C–S–H gel. 1 H populations, distinguished by their different mobilities, can be identified and assigned to water confined within the pores of the C–S–H gel, to crystallization water and Portlandite, and to hydroxyl groups. Changes of the TD-NMR parameters during hydration are in agreement with the expected effects of the different additives, which, as it is known, can substantially modify the rate of reactions and the properties of cementitious pastes. Endodontic cements are suitable systems to check the ability of this non-destructive technique to give insight into the complex hydration process of real cement pastes.

Ocean acidification is predicted to impact ecosystems reliant on calcifying organisms, potentially reducing the socioeconomic benefits these habitats provide. Here we investigate the acclimation potential of stony corals living along a pH gradient caused by a Mediterranean CO2 vent that serves as a natural long-term experimental setting. We show that in response to reduced skeletal mineralization at lower pH, corals increase their skeletal macroporosity (features >10 μm) in order to maintain constant linear extension rate, an important criterion for reproductive output. At the nanoscale, the coral skeleton's structural features are not altered. However, higher skeletal porosity, and reduced bulk density and stiffness may contribute to reduce population density and increase damage susceptibility under low pH conditions. Based on these observations, the almost universally employed measure of coral biomineralization, the rate of linear extension, might not be a reliable metric for assessing coral health and resilience in a warming and acidifying ocean., Global warming and ocean acidification impact coral ecosystems. Here, the authors show higher skeletal porosity and reduced bulk density at lower pH in corals living along a natural pH gradient in the Mediterranean, which may contribute to reduce population density and increase damage susceptibility.

Editorial of the Proceedings of the 12th International Bologna Conference on Magnetic Resonance in Porous Media (MRPM12), 9-13 February 2014, Victoria University of Wellington, Wellington, New Zealand

One of the most promising recycling procedures of some industrial organic wastes, as paper mill sludge (PMS), is soil amendment. In this field of application, PMS and natural soil are mixed together according to specific regulations to avoid potential environmental risks that can arise after land restoration, and hence, the mixture must be scrupulously characterized and evaluated, also by means of different analytical techniques. Proton nuclear magnetic resonance (1H NMR) is a powerful, noninvasive and nondestructive technique to investigate natural and artificial porous media, and it is a promising tool to characterize amended soils as well, also in the light of the experimental difficulties that these materials generally entail. In this work, NMR micro- and macro-porosity were related to total organic carbon (TOC) content, and information on the behavior of organic matter (OM) contained inside the mineral matrix was obtained. In particular, a high presence of TOC shows that micropores are forbidden to the saturating water, giving evidence of OM interactions with soil microstructure. This kind of analysis has clear implications in the characterization of amended soil biological processes, such as biodegradation. © 2013, Islamic Azad University (IAU).

In fresh pork loin, the information concerning fat content is very important, both from the consumer as well as from the nutritional point of view. Knowing the fat content allows industry to classify the fresh loins accordingly. Fat content in loins is a factor related to moisture variability; therefore on-line, non-destructive technologies that could be used in an industrial environment to predict fat-to-moisture ratio are of special interest for companies from the pork processing sector. The time-domain nuclear magnetic resonance (1H TD-NMR), and in particular Relaxometry and Imaging (MRI), has been introduced as a promising alternative to traditional food characterization method due to its rapidity, simplicity, and potential for on-line non-destructive measurements. In this paper, the authors introduce original and innovative procedures using NMR Relaxometry and 1H nuclei imaging which can be employed to estimate the fat content in intact pork loins by exploiting the difference between fat and water longitudinal relaxation time (T1) distributions. They demonstrate how analysis of the quasi-continuous distributions of T1 in fresh intact loins allowed them to obtain a significant relationship between F/W ratios determined from Relaxometry and chemical analysis. This chapter also explains how both NMR Relaxometry and Imaging can estimate the fat-to-moisture ratios in loins in a non-destructive way.

The collection and composting of organic waste from both households and industries has long been recognized as a valuable contribution to waste management. The first step towards a “zero-waste” concept, in particular in the food processing sector, is the identification, quantification and characterization of residues. Thus considerable efforts have been focused towards the definition of compost maturity in order to decide on the quality of compost. Therefore the principal requirement of a compost for its safe use is a high degree of maturity, which implies a stable organic matter (OM) content and the absence of phytotoxic compounds and plant or animal pathogens. Magnetic Resonance Relaxometry (MRR) and Imaging (MRI) of hydrogen nuclei are optimal candidates to give information on the degree of degradation and maturity of compost, especially when there is needed a careful non-invasive and non-destructive characterization. Because many foods are proton-rich, e.g., from water, fat, carbohydrates, and proteins, MRR is a common tool to gain information about the composition and internal structure of foods, permitting also to monitor the compositional and structural modifications when they undergo natural or artificial processes. Since the relaxation times (longitudinal T1 and transverse T2) variations change the image contrast, MRI can easily monitor the structural changes in foods during processing and storage. MRI can detect and show internal variations in the water content, as well as changes in water interaction with cellular tissues. In this work typical MRR parameters as T1 and T2, and 1H signal amplitude were related to water content, and to micro and molecular structure of the compost itself, to follow the compost phases. Furthermore the authors used Quantitative Relaxation Tomography (QRT), a method to measure locally the relaxation times by means of MRI images. This technique allowed them to locally follow the FW biodegradation over time and to evaluate the maturity and quality parameters. In summary, matching magnetic resonance techniques with other standard analyses could be of great importance to fully describe the stages of composting and define the degree of compost maturity.

The inversion of two-dimensional Nuclear Magnetic Resonance (NMR) data requires the solution of a rst kind Fredholm integral equation with a two-dimensional tensor product kernel and lower bound constraints. For the solution of this ill-posed inverse problem, the recently presented 2DUPEN algorithm [V. Bortolotti et al., Inverse Problems , 33(1), 2016] uses multi- parameter Tikhonov regularization with automatic choice of the regularization parameters. In this work, I2DUPEN, an improved version of 2DUPEN that implements Mean Windowing and Singular Value Decomposition filters, is deeply tested. The reconstruction problem with filtered data is formulated as a compressed weighted least squares problem with multi-parameter Tikhonov regularization. Results on synthetic and real 2D NMR data are presented with the main purpose to deeper analyze the separate and combined e effects of these filtering techniques on the reconstructed 2D distribution.

Cement hydration occurs when water is added to cement powder, leading to the formation of crystalline products like Portlandite and the quasi-amorphous, poorly crystalline, calcium silicate hydrate (C-S-H) gel. Despite its importance in determining the final properties of the cement, many models exist for the nano and sub-nano level organization of this liquid stone. H-1 NMR relaxometry in White Portland Cement paste during hydration allowed us to monitor the formation and evolution of the multiscale porosity of the cement, with the formation of structures at nano and sub-nano levels of C-S-H gel (calcium silicate interlayer water, water in small and large gel pores) along with three low-mobility H-1 pools, identified as H-1 nuclei in C-S-H layers, likely belonging to OH groups, with H-1 nuclei in Portlandite, and in crystal water of Ettringite. By assuming these assignments, our data allowed us to compute the distances of pairs of H-1 nuclei in Portlandite and in crystal water ((1.9 +/- 0.2) angstrom and (1.6 +/- 0.1)angstrom, respectively), consistent with the known values of these distances. The picture of the porous structure at nano and sub-nano levels emerging from our results is consistent with the Jennings colloidal model for C-S-H gel. Moreover, the constant values observed during hydration of parameters extracted from our data analysis strongly support that model, being compatible with the picture of C-S-H gel developing in comparable-sized clumps of the same composition, but not easily interpretable by models proposing quasi continuous sheets of C-S-H layers.

Magnetic resonance imaging and relaxation analysis are combined in a spatially resolved technique (relaxation tomography), which is able to quantify the parameters connected to the local structure in the internal regions of a porous material saturated by water, giving information on the pore space structure beyond the nominal instrumental resolution. Voxel-by-voxel longitudinal (T1) and transverse (T2) relaxation curves are acquired in order to obtain T1, T2 and S(0) maps, where S(0) is the extrapolation to zero time of the total equilibrium magnetization corrected for T2 decay. The proposed method permits evaluation of the porosity (ratio of pore space to total volume), at different length scales, from the sample to the voxel, not all achievable by traditional methods. More striking is its ability to describe how porosity is shared among different classes of surface-to-volume ratios of diffusion cells (the regions that the individual water molecules, starting at their particular positions, can experience...

The effects of protective hydrophobic products applied to porous media such as stone or mortar vary greatly with the product, the porous medium, and the mode of application. Nuclear Magnetic Resonance (NMR) measurements on fluids in the pore spaces of both treated and untreated samples can give information on the contact of the fluid with the internal surfaces, which is affected by all the above factors. Continuous distributions of relaxation times T1 and T2 of water in the pores of both synthetic and natural porous media were obtained before and after hydrophobic treatment. The synthetic porous media are ceramic filter materials characterized by narrow distributions of pore dimensions and show that the treatment does not produce large changes in the relaxation times of the water. For three travertine samples most of a long relaxation time component, presumably from the largest pores, remains after treatment, while the amplitude of an intermediate component is greatly reduced. For three pudding-stone samples, treatment leads to a substantial loss from the long component and an even greater loss from the intermediate component.

The inversion of two-dimensional NMR data is an ill-posed problem related to the numerical computation of the inverse Laplace transform. In this paper we present the 2DUPEN algorithm that extends the Uniform Penalty (UPEN) algorithm [Borgia, Brown, Fantazzini, {\em Journal of Magnetic Resonance}, 1998] to two-dimensional data. The UPEN algorithm, defined for the inversion of one-dimensional NMR relaxation data, uses Tikhonov-like regularization and optionally non-negativity constraints in order to implement locally adapted regularization. In this paper, we analyze the regularization properties of this approach. Moreover, we extend the one-dimensional UPEN algorithm to the two-dimensional case and present an efficient implementation based on the Newton Projection method. Without any a-priori information on the noise norm, 2DUPEN automatically computes the locally adapted regularization parameters and the distribution of the unknown NMR parameters by using variable smoothing. Results of numerical experiments on simulated and real data are presented in order to illustrate the potential of the proposed method in reconstructing peaks and flat regions with the same accuracy.

In order to well distinguish different tissues of the human body by magnetic resonance imaging (MRI), it is of great importance to find procedures to improve the image contrast. In particular, a valuable feature is to image only specific parts of organs and/or tissues while ignoring all the others. Dedicated MRI sequences able to filter the 1 H nuclei signals based on the different longitudinal relaxation times (T1) of the tissues have been developed. Standard signal selection/attenuation sequences, such as the Short Time Inversion Recovery and Multiple Inversion Recovery, have the effect to zero the signal for a discrete number of T1 values. Parametrically Enabled Relaxation Filters with Double and multiple Inversion (PERFIDI) sequences act on a range of T1 values and behave as an electronic band-pass or high-pass or low-pass filters. PERFIDI filters are therefore primarily focused on the components that pass through, rather than on those that are blocked. These filters have been developed and tested by nuclear magnetic resonance relaxometry. Here, these sequences have been validated for MRI on phantom samples to mimic T1 distributions present in tissues. Preliminary applications show that PERFIDI filters can effectively work on a range of T1 values to give well contrasted images.

For a large suite of consolidated sandstone samples low in shale content we have measured the permeability k , irreducible water saturation S wi , porosity φ, electrical-resistivity formation factor F , porosity by NMR, geometric-mean relaxation times T 1 g , and stretched-exponential relaxation times T 1 s (or T 1 s ) is the decisive parameter for the estimation of k or S wi of porous sandstones by other than direct measurements of these quantities. The additional use of φ or F brings appreciable, but not decisive, improvement. We show isovalue maps of the error factor δ, which show substantial regions of near-minimum values of δ and show basic compatibility of our estimators for permeability with different published estimators. The exponents of T 1 g (or T 1 s ) in our power-law estimators and those of various published estimators for k are not very far from 2.0 if either or both of φ and F are also used in the estimators.