Environmental NMR: Fast-field-cycling Relaxometry

Conte, Pellegrino; Alonzo, G.

doi:10.1002/9780470034590.emrstm1330

Cited by 27 publications

(107 citation statements)

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“…The samples were immediately analyzed by a Stelar Spinmaster Fast Field Cycling Relaxometry instrument at a constant temperature of 25°C. The bases for the FFC NMR relaxometry have been already reported in De Pasquale et al (2012) and Conte and Alonzo (2013). For this reason, here, we report only the experimental conditions applied for the present study.…”

Section: Nmr Relaxometry Investigationsmentioning

confidence: 99%

“…Field switching time was 3 ms, while spectrometer dead time was 15 μs. All the recovery curves were evaluated by the UPEN algorithm (Alma Mater Studiorum, Università di Bologna, Italy) (Conte and Alonzo 2013) with the aim to obtain the longitudinal relaxation time (T 1 ) distributions, and therefore, information on the way water molecules are trapped in each sample (Conte et al 2013a). …”

Section: Nmr Relaxometry Investigationsmentioning

confidence: 99%

“…The high energy moisture characteristic (HEMC) technique was applied in order to investigate changes in aggregate stability through measurement of water retention curve at high matric potential (CollisGeorge and Figueroa 1984;Crescimanno et al 1995;Mamedov 2002, Mamedov et al 2010;Ouyang et al 2013). 1 H NMR relaxometry with fast field cycling (FFC) setup was applied to monitor pore size distribution through the evaluation of the water dynamics in biochar/sandy-clay soil samples (Conte and Alonzo 2013). Results revealed that increasing amount of biochar added to the sandy-clay soil improved aggregate stability and increased soil porosity, thus improving the amount of water that the biochar amended soil was able to retain.…”

Section: Introductionmentioning

confidence: 99%

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Structure alteration of a sandy-clay soil by biochar amendments

et al. 2014

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Purpose The aim of the present study was to investigate structure alterations of a sandy-clay soil upon addition of different amounts of biochar (f bc ). Materials and methods All the f bc samples were analyzed by high energy moisture characteristic (HEMC) technique and 1 H nuclear magnetic resonance (NMR) relaxometry. HEMC was applied in order to evaluate aggregate stability of biocharamended soil samples. 1 H NMR relaxometry experiments were conducted for the evaluation of the pore distributions through the investigation of water dynamics of the same samples.Results and discussion The HEMC technique revealed improvement in aggregate stability through measurements of the amount of drainable pores and the stability ratio. The latter increased as the amount of biochar was raised up. The 1 H NMR relaxometry revealed a unimodal T 1 distribution for both the sole sandy-clay soil and the biochar. Conversely, a bimodal T 1 distribution was acquired for all the different f bc samples. Conclusions Improvement in aggregate stability was obtained as biochar was progressively added to the sandy-clay soil. A dual mechanism of water retention has been hypothesized. In particular, intra-aggregate porosity was indicated as the main responsible for molecular water diffusion when f bc comprised between 0 and 0.33. Conversely, inter-aggregate porosity resulted predominant, through swelling processes, when f bc overcame 0.33.

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Section: Nmr Relaxometry Investigationsmentioning

confidence: 99%

Section: Nmr Relaxometry Investigationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Structure alteration of a sandy-clay soil by biochar amendments

et al. 2014

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“…NMR method allows determining group composition of bitumen and BPB with an accuracy of 3%, this will allow us to estimate the composition changes, as well as the convergence of the results obtained by other methods (Conte and Alonzo, 2013;Kimmich andAnoardo, 2004, Bayer et al, 2010).…”

Section: Discussionmentioning

confidence: 96%

“…Nuclear magnetic relaxation (NMR) is one of the modern instrumental methods of physical chemistry (Kimmich and Anoardo, 2004;Conte and Alonzo, 2013, Xu et al, 2013, Bayer et al, 2013Haber-Pohlmeier et al, 2013) and is a fundamental property of nuclear magnetism, characterizing the dynamics of nuclear spins system in the oil bitumen-polymer systems.…”

Section: Introductionmentioning

confidence: 99%

Structural Dynamic Study of Roof Waterproofing Materials

Кемалов¹,

Kemalov²,

Валиев³

et al. 2014

MAS

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The present research was aimed to develop the scientific applied principles and technologies of composite bituminous materials for civil engineering based on the investigation of the structures of polymer modifier and bitumen-polymer binder (BPB) on its basis with the use of nuclear magnetic resonance (NMR). The method of pulsed NMR was chosen as one of the rapid analysis methods that can be used for the analysis of bitumen-polymer systems, especially when assessing the group chemical composition of residual oil feedstock (ROF), bitumens and composite materials based on them. Using the method of pulsed NMR the regularities of the impact of modifier component composition on the changes of structural-group composition of the original and modified products were specified. Based on the results of research the optimal ratio of bitumen-polymer binder components was investigated, the manufacturability of the process for obtaining of composite bituminous materials for civil engineering with the aim of optimizing the quality of the final products was evaluated. Pulsed NMR -spectroscopy is suggested as input and output quality control of bituminous products. The regularities of redistribution of the phases with different molecular mobility and their relationship with the binder components were investigated. Rapid technique for quantifying the content of polymer in the solvent was developed.

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Measuring hydrological connectivity inside a soil by low field nuclear magnetic resonance relaxometry

Conte

Ferro

2017

Hydrological Processes

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Hydrological connectivity inside the soil is related to the spatial patterns inside the soil (i.e., the structural connectivity). This, in turn, is directly associated with the physical and the chemical processes at a molecular level (i.e., the functional connectivity). Nuclear magnetic resonance (NMR) relaxometry can be successfully applied to reveal both structural and functional components of soil hydrological connectivity. In the present study, the low field NMR relaxometry was applied on water suspended soils sampled at the upstream-and downstream-end of three different length plots. Also the sediments collected from the storage tanks at the end of each plot were water suspended and monitored by NMR relaxometry. The results from the NMR investigations were elaborated by using a mathematical approach in order to quantify both the functional and structural connectivity components. In particular, following integration of the T 1 distribution curve, an S-shaped curve was obtained. It revealed two plateaus corresponding to the shortest (low component) and the longest (high component) intervals of relaxation times, respectively. According to relaxometry theory, the two T 1 intervals, associated to the different plateaus, were attributed to micro and macro soil pores, respectively. The two T 1 intervals were used to define a functional connectivity index, while the central part of the S-shaped distribution was used to define a structural connectivity index. Here we provide the physical meaning of the our mathematical approach, thereby revealing that functional connectivity index increases with plot length, as a result of a selective eroded particle transport. Moreover, the relationship structural connectivity index versus plot length resulted quasi-independent of grainsize distribution, whereas the values of the structural connectivity index for the sediment samples resulted lower than those obtained for the corresponding soils.

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Environmental NMR: Fast-field-cycling Relaxometry

Cited by 27 publications

References 61 publications

Structure alteration of a sandy-clay soil by biochar amendments

Structure alteration of a sandy-clay soil by biochar amendments

Structural Dynamic Study of Roof Waterproofing Materials

Measuring hydrological connectivity inside a soil by low field nuclear magnetic resonance relaxometry

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