Noninvasive nuclear magnetic resonance profiling of painting layers | Request PDF Home Art Visual Arts Painting ArticleNoninvasive nuclear magnetic resonance profiling of painting layers July 2008 Applied Physics Letters 93(3):033505-033505-3 DOI: 10.1063/1.2963026 Authors: Federica Presciutti Università degli Studi di Perugia Juan Perlo Magritek GmbH Federico Casanova Magritek Inc. Stefan Glöggler Max Planck Institute for Biophysical Chemistry Show all 8 authorsHide Request full-text PDFTo read the full-text of this research, you can request a copy directly from the authors. Request full-text Download citation Copy link Link copied Request full-text Download citation Copy link Link copied To read the full-text of this research, you can request a copy directly from the authors. Citations (64) References (16) Abstract In this work we demonstrate the potential of single-sided nuclear magnetic resonance (NMR) sensors to access deeper layers of paintings noninvasively by means of high-resolution depth profiles spanning several millimeters. The performance of the sensor in resolving painting structures was tested on models for which excellent agreement with microscopy techniques was obtained. The depth profiling NMR technique was used in situ to investigate old master paintings. The observation of differences in NMR relaxation times of tempera binders from these paintings and from artificially aged panels raises the possibility to differentiate between original and recently restored areas. Discover the world's research 20+ million members 135+ million publications 700k+ research projects Join for free No full-text available To read the full-text of this research, you can request a copy directly from the authors. Request full-text PDF Citations (64) References (16) ... Single-sided nuclear magnetic resonance (NMR) has been used to non-invasively study objects and chemical processes including oil well logging [4,5], food [6][7][8], manufacturing procedures [9,10], paintings [11][12][13][14][15], instruments [16], ceramics [17][18][19], paper [20], and building materials [21]. The use of permanent magnets in single-sided devices greatly reduces engineering and operation complexity associated with traditional NMR equipment. ... ... The small size of the single-sided magnets allows them to be mounted on mechanical lifts that can control motion of the entire magnet set-up. This facilitates NMR "profiling" or one-dimensional imaging of paint layers with resolution on the scale of tens of microns [11,[22][23][24]. By utilizing the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence, spin-spin relaxation times (T 2 ) can be measured [25,26]. ... ... CPMG experiments were carried out on the area of paint providing the greatest signal as determined by measuring a 1-D depth profile [11]. For Sample Groups B, C, and D, the CPMG measurements were made using a pulse length of between 4.75 and 5.0 μs (B 1 pulse power = 50-53 kHz), and 128 echoes were collected with an echo time of 60 μs. ... Physical and chemical properties of traditional and water-mixable oil paints assessed using single-sided NMR Article Mar 2017 MICROCHEM J Nicholas A. Udell Robyn E Hodgkins Barbara Berrie Tyler Meldrum Single-sided NMR and gas chromatography were used in tandem to investigate the physical and chemical differences between traditional linseed oil paint and water-mixable oil paint. Water-mixable oil paints contain an emulsifier that confers water miscibility, but it may also affect the curing process and the intermolecular network formed in a cured paint film. Comparisons of paint samples of different compositions and ages show that the emulsifier changes both the chemical and physical properties of the paint films, though at different curing times and to different extents depending on the paint formulation. This research highlights the utility of NMR relaxometry in cultural heritage analysis, and suggests further study into the effects of agents affecting the curing process and reactions within a paint film. View Show abstract ... This technique permits the identification of characteristic vibrations associated with functional groups in a given molecule [31,32]. Typical applications include analysis of paint pigments and binders, lacquers and finishes. ... ... Museum curators, art historians, restoration scientists, and archaeologists have many analytical tools at their disposal to study objects with cultural heritage significance. These analytical tools include: 1. ultraviolet-visible (UV-vis) absorption, reflection, fluorescence, and phosphorescence spectroscopy [1-5]; 2. infrared (IR) (also referred to by the instrumentation type Fourier transform IR (FTIR)) absorption and reflection spectroscopy [6][7][8][9][10][11] in the near, shortwave, mid, and far regions of the spectrum; 3. Raman spectroscopy (RS) [12], surface enhanced Raman spectroscopy (SERS) [13,14], and surface enhanced resonance Raman spectroscopy (SERRS) [15] 5. x-ray fluorescence (XRF) [17,18], energy dispersive XRF (EDXRF), and wavelength dispersive XRF (WDXRF), and confocal XRF [19] spectroscopy; 6. mass spectroscopy (MS), laser photolysis gas chromatography mass spectroscopy (LP GC-MS) [20,21], and pyrolysis gas chromatography mass spectroscopy (Py GC-MS) [22]; 7. neutron activation analysis (NAA) [23]; 8. particle-induced x-ray emission (PIXE) spectroscopy [24,25]; 9. Mössbauer spectroscopy [26]; 10. conventional liquid phase nuclear magnetic resonance (NMR) [27,28], solid state NMR (SSNMR) [29,30], and unilateral time resolved NMR spectroscopy [31,32]; and 11. electron paramagnetic resonance (EPR) spectroscopy. ... Concordant ESR and TL depositional age of Romanian Plane loess Chapter Oct 2020 L.C. Tugulan Mihail Secu Vasile Bercu Octavian G Duliu To determine the age of a 2.8 m loess horizon situated in the Eastern Romanian Plane, the independent age methods based on the accumulation of radiation defects, i.e. thermoluminescence (TL) and electron spin resonance (ES), were used for the same quartz fraction. In both cases, the additive method was used to determine the local paleodose (PD) while the local annual dose rate was recalculated starting from the content of radioactive elements in soil determined by high resolution gamma-ray spectrometry. Final results gave coincident results within experimental uncertainties of 19.85 ± 2.60 and 20.38 ± 2.93 ka for TL and respectively for ESR age. One possible explanation of the relatively high level of age uncertainties could be related to the additive method of the estimation of the PD by extrapolating the signal to dose dependency. View Show abstract ... Oil-binding medium was used in northern Europe since the 13th century, on its introduction in Italy in the 15th century oil painting seems mainly to have been effected using walnut oil but use of linseed oil became more general in the 16th century (i.e Mona Lisa of Leonardo Da Vinci, 1503-1517) [1,2]. Due to the preciousness of the painting, we used in situ portable NMR to obtain, in a fully nondestructive and non-invasive way, the stratigraphy of a great number of regions of the painting [3][4][5]. The successive sampling was carried out according to the results obtained by in situ NMR and was limited to regions near gaps, cracks, and in those regions partially removed during the 20th century restoration. ... ... Starting from the surface of the painting, the two regions labeled as 1 and 3, with an intense NMR signal were ascribed to the painting layer and the wood respectively, whereas the intermediate one labeled as 2, with the weakest intensity, was ascribed to the primer (see Fig. 2a). The thickness of the layers was calculated by measuring the distance from the position of half maximum amplitude of the first edge to the equivalent point of the second edge [4]. The value of the thickness of the painting layer composed by varnishes, binders and pigments was found to be 650 ± 50 μm in the 14th century region, 800 ± 50 μm in the 16th century re-painted region, and 850 ± 50 μm in the 20th century re-painted region. ... Advanced NMR methodologies and micro-analytical techniques to investigate the stratigraphy and materials of 14th century Sienese Wooden Paintings Article Mar 2016 Microchem J A. Atrei Nadia Marchettini Valeria Di Tullio Donatella Capitani View ... Figure 1b shows a device consisting of a permanent magnet mounted on a precision lift. Application of these devices has opened a number of new possibilities also in the field of cultural heritage [27][28][29][30][31][32][33][34]. NMR sensor with a uniform gradient to resolve the near surface structure of arbitrarily large samples, the sensor is placed on a lift that allows one to move the magnetic field inside the object to be analyzed with micrometric steps, sensor by RWTH Aachen University, Aachen, Germany [26]. ... ... NMR stratigraphy is an analytical technique which may be applied in situ to reveal different layers of a painting in a fully non-invasive manner. The first stratigraphy was published by Presciutti et al. [27]. With this technique, layers of different materials can be detected and their thickness can be measured. ... Applications of Nuclear Magnetic Resonance Sensors to Cultural Heritage Article Full-text available Apr 2014 SENSORS-BASEL Noemi Proietti Donatella Capitani Valeria Di Tullio In recent years nuclear magnetic resonance (NMR) sensors have been increasingly applied to investigate, characterize and monitor objects of cultural heritage interest. NMR is not confined to a few specific applications, but rather its use can be successfully extended to a wide number of different cultural heritage issues. A breakthrough has surely been the recent development of portable NMR sensors which can be applied in situ for non-destructive and non-invasive investigations. In this paper three studies illustrating the potential of NMR sensors in this field of research are reported. View Show abstract ... The possibility of using the NMR-MOUSE as a scientific tool for the nondestructive analysis of paintings had been tested on modern model easel paintings on wood prepared following the procedures of old masters. The wood panels were first covered by a layer of primer and then a paint layer from copper-and cobalt-based pigments mixed in binder [12]. Presciutti et al. used the NMR-MOUSE to gather depth profiles of these samples with a resolution of 10 μm. ... ... Differences in relaxation of paint layers are caused by the type of pigment, the type of binder, the history of aging [12], and the history of restoration. Apart from the pigments, aging and restoration impact the state of the binder by loss of small molecules and chemical changes invoked by exposure to oxidation, heat, and solvents. ... Nondestructive Testing of Objects from Cultural Heritage with NMR Chapter Jan 2018 Maria Baias Bernhard Bluemich View ... In recent years several issues regarding cultural heritage have been afforded by NMR [10][11][12]. Among these are wall paintings and oil paintings [13][14][15][16][17][18][19], paper [20,21], moisture in historical walls [22][23][24], lead soaps [25-28], pigments [29,30], organic paint binders [31,32], modern art materials [33-35], archaeological and fossil wood [36-39], ancient leather [40,41], amber [42,43], ancient pottery [44-46], porous stones [47-51], and advanced cleaning and conservation systems for cultural heritage [52-55]. ... ... NMR stratigraphy is able to reveal non-invasively and in situ the different layers of a painting. The first NMR stratigraphy was published few years ago by Presciutti et al. [16]. The stratigraphy encodes the amplitude of the 1 H-NMR signal as a function of the depth scanned. ... Nuclear Magnetic Resonance, a Powerful Tool in Cultural Heritage Article Full-text available Jan 2018 Noemi Proietti Donatella Capitani Valeria Di Tullio In this paper five case studies illustrating applications of NMR (Nuclear Magnetic Resonance) in the field of cultural heritage, are reported. Different issues were afforded, namely the investigation of advanced cleaning systems, the quantitative mapping of moisture in historic walls, the investigation and evaluation of restoration treatments on porous stones, the stratigraphy of wall paintings, and the detection of CO2 in lapis lazuli. Four of these case studies deal with the use of portable NMR sensors which allow non-destructive and non-invasive investigation in situ. The diversity among cases reported demonstrates that NMR can be extensively applied in the field of cultural heritage. View Show abstract ... The type of binder, its state and the type and concentration of the embedded pigments determine the relaxation times T 1 and T 2 observed by NMR. 10,26 For accelerated F I G U R E 1 NMR-MOUSE set up at the State Bureau of Criminial Investgations in Berlin measuring a painting forged by Wolfgang Beltracchi. Two of the four magnets, rf-coil and sensitive slice are overlaid to the NMR-MOUSE. ... ... The sensor is mounted on a translation stage that allows to place the sensitive slice into the paint layer, which is aligned in parallel with the sensitive slice light aging of tempera paint, it has been found that T 2 decreases with increasing aging time, while natural aging of master paintings over centuries decreases both, T 1 and T 2 ( Figure 2B). 26 The gifted forger of modern art, Wolfgang Beltracchi 27 has baked or ironed his paintings to artificially age the paint. The light-aging study ( Figure 2B) and the insights gained from accelerated aging and natural aging of synthetic polymer materials suggest that nondestructive NMR relaxometry with the NMR-MOUSE may reveal the differences between Beltracchi's accelerated aging of paint and the paint aged naturally over decades in known originals on display in museums. ... Aging of polymeric materials by stray‐field NMR relaxometry with the NMR‐MOUSE Article Mar 2018 CONCEPT MAGN RESON A Bernhard Blümich The sensitivity of NMR relaxation to molecular motion is explored to study the aging of polymer materials and paint binder in master paintings. Polymeric materials are formulated from macromolecules with a distribution of molecular weights and low molecular weight additives. Their physical and chemical properties change with time due to exposure to temperature, mechanical stress, and solvents. These conditions lead to physical and chemical aging, which can proceed naturally over longer times or accelerated under artificial conditions in shorter times. Either procedure bears a particular signature on the molecular mobility, which can be probed nondestructively by the NMR relaxation times T1 and T2. Natural aging and accelerated temperature‐ and solvent‐induced aging are summarized for synthetic polymer materials and compared to aging of binders in the paint layers of paintings aged naturally over hundreds of years and aged artificially by solvent‐cleaning procedures during restoration or at elevated temperature during forgery. View Show abstract ... NMR MOUSE is a relatively small and compact device design to perform noninvasive and nondestructive analyses, highly valued in the field of cultural heritage. Objects like mummies (Rühli et al., 2007), paintings (Presciutti et al., 2008), frescoes (Proietti et al., 2005) and parchments (Badea et al., 2008;Masic et al., 2012) were successfully analysed using NMR-MOUSE. ... UNILATERAL NMR FOR DAMAGE ASSESSMENT OF VEGETABLE- TANNED LEATHER. CORRELATION WITH HYDROTHERMAL PROPERTIES Conference Paper Full-text available Oct 2014 Claudiu Sendrea Elena Badea Lucretia Miu Horia Iovu Unilateral NMR has proven to be a valuable tool in the field of collagen-based cultural heritage where non-destructive analyses are highly demanded. Old leather is a collagen-based biomaterial made from animal hides chemically treated by vegetable or mineral tanning to increase chemical and physical durability and confer desired handling and working characteristics. In this study unilateral Nuclear Magnetic Resonance (NMR) combined with shrinkage temperature measurement by the Micro Hot Table (MHT) method were applied to evaluate the conformational, structural and stability changes of variously vegetable tanned leathers exposed to accelerated ageing by heating at 70 °C in controlled atmosphere at 30% relative humidity (RH) and irradiated with 4000 lx in the visible light region for 8, 16, 32 and 64 days. Longitudinal relaxation time T1 values, measured by NMR MOUSE portable equipment using a saturation recovery sequence, showed specific variations depending on both animal species and tanning agent, and ageing time. Collagen fibres' shrinkage temperature Ts values evaluated using the home made MHT equipment available at INCDTP-ICPI, Bucharest, complemented the hydrothermal information on fibre level. View Show abstract ... The position of the excited slice is moved inside the sample by means of a high-precision lift that repositions the sensor with respect to the sample. The use of these sensors has already opened new possibilities (Rühli et al., 2007;Presciutti et al., 2008;Blümich et al., 2010a and b;Del Federico et al., 2010;Di Tullio et al., 2011Proietti et al., 2011Proietti et al., , 2014. ... Nuclear Magnetic Resonance to investigate inorganic porous materials of interest in the cultural heritage field Article Full-text available Jun 2015 EUR J MINERAL Giorgio Trojsi Valeria Di Tullio Donatella Capitani Noemi Proietti Nuclear Magnetic Resonance (NMR) can be successfully applied to a wide number of organic, inorganic, and hybrid materials regarding cultural heritage. High-resolution solid-state NMR provides information on the structure of materials, and portable NMR devices allow non-destructive and non-invasive in situ investigation of variably sized objects. This result is possible by combining open magnets and surface radiofrequency coils to generate a sensitive volume external to the sensor and inside the object under investigation. In this paper we focus on the application of NMR to investigate inorganic porous materials such as pottery, plasters, and stones from cultural heritage sites. 27Al MAS and 3QMAS, and 29Si MAS high-resolution solid-state NMR along with spectral deconvolution allowed for the investigation of the chemical structure of ancient pottery. Portable unilateral NMR was used to investigate, in a non-invasive and non-destructive way, the porous structure of pottery. The effect of protective-consolidating treatments on plaster was carefully investigated by 1H NMR depth profiles that allowed for scanning with micrometric resolution of plaster specimens. Changes occurring in the total open porosity after treatments were also evaluated. NMR diffusion measurements provided information on the restricted geometry of the porous structure of two types of biocalcarenite and tuff. A suitable processing of collected data enabled us to define the average pore radius and pores’ interconnection in these materials. View Show abstract ... The study of objects of cultural heritage by compact and mobile NMR is conducted predominantly with stray-field instruments such as the NMR-MOUSE because nondestructiveness is essential in nearly all cases [1,13,38,39] with the exception of moisture monitoring in large building structures, a case for which the NMR DIP-stick has been designed (see above) [148]. Objectives pursued by stray-field NMR in the context of cultural heritage are moisture mapping [149,150], contributing to the optimization of stone conservation strategies [151], studying the mortar base of wall paintings [152,153], assessing bone degradation [13,154], monitoring the water distribution in wooden panels such as easel paintings [155], studying the stratigraphy and binder states of paintings [156], assisting in the development of restoration techniques for easel paintings [157,158], and studying the degradation mechanisms of parchment and leather [159][160][161]. The overriding goals are to understand the states of degradation, to identify the extent of past restoration and conservation measures, and to monitor the impact of conservation efforts on the state of the object. ... Mobile and Compact NMR Chapter Jan 2016 Bernhard Bluemich NMR with mobile and compact devices is experiencing considerable growth in recent years in particular since instruments have become available, which are capable not only of measuring NMR relaxation but also images and high-resolution spectra. Based on permanent magnet technology, compact tabletop NMR instruments measure samples of materials and solutions positioned inside the magnet, while compact mobile instruments measure material properties of intact objects and samples nondestructively in the inhomogeneous stray field outside the magnet. Following a brief introduction to NMR with homogeneous and inhomogeneous magnetic fields and to the concepts of permanent center- and stray-field NMR magnets, the evolution of the technology over the past 10 years is reviewed and illustrated with selected applications. Relaxation and diffusion measurements find use in the analysis of foods, biological tissues, polymer materials, porous media, and objects of cultural heritage. Compact imaging instruments are mainly employed to study crops and plants as well as transport phenomena in chemical engineering and geophysics. Tabletop NMR spectrometers find increasing use in educational institutions and for chemical analysis and reaction monitoring on the workbench and in the fume hood of the synthesis laboratory, and they are being explored as a tool for process control. View Show abstract ... Various noninvasive and noncontact modalities which can provide in-situ quantitative information in depth, such as confocal x-ray fluorescence (with elemental distribution contrast) 2 , femtosecond pump-probe microscopy (with molecular and structural constrast) 3 , nuclear magnetic resonance (NMR) (with 1 H abundance constrast) 4 , and optical coherence tomography (with structural constrast) 5 , are under active research. Nonetheless, to date, the aforementioned optical techniques, as well as x-ray fluorescence (the emitted photon is optical) have been limited to demonstrations permitting measurements to depths up to only tens or ~200 μm due to strong optical attenuation, while NMR has only been used to demonstrate several Z-scans across a painting 6 . ... Global mapping of stratigraphy of an old-master painting using sparsity-based terahertz reflectometry Article Full-text available Nov 2017 Junliang Dong Alexandre Locquet Marcello Melis D.s. Citrin The process by which art paintings are produced typically involves the successive applications of preparatory and paint layers to a canvas or other support; however, there is an absence of nondestructive modalities to provide a global mapping of the stratigraphy, information that is crucial for evaluation of its authenticity and attribution, for insights into historical or artist-specific techniques, as well as for conservation. We demonstrate sparsity-based terahertz reflectometry can be applied to extract a detailed 3D mapping of the layer structure of the 17th century easel painting Madonna in Preghiera by the workshop of Giovanni Battista Salvi da Sassoferrato, in which the structure of the canvas support, the ground, imprimatura, underpainting, pictorial, and varnish layers are identified quantitatively. In addition, a hitherto unidentified restoration of the varnish has been found. Our approach unlocks the full promise of terahertz reflectometry to provide a global and detailed account of an easel painting’s stratigraphy by exploiting the sparse deconvolution, without which terahertz reflectometry in the past has only provided a meager tool for the characterization of paintings with paint-layer thicknesses smaller than 50 μm. The proposed modality can also be employed across a broad range of applications in nondestructive testing and biomedical imaging. View Show abstract ... Painted surfaces including wood, stone,a nd canvas,a re prominent objects where mobile NMR sensors can help unravel their history and optimize conservation and restora- tion strategies.T he flat sensitive slice of the NMR-MOUSE combined with the portability of the sensor are valuable assets for mapping and characterizing thin-layer stratigraphy across depth ranges of up to 25 mm. [35][36][37][38] Wall paintings and frescoes are particularly unique in the sense that the stratigraphy of their mortar base bears the signature of the craftsmen at the time of painting,a ltering,and restoring. ... Cultural Heritage Studies with Mobile NMR Article Mar 2018 ANGEW CHEM INT EDIT Christian Rehorn Bernhard Bluemich Nuclear Magnetic Resonance (NMR) provides in‐situ information about selected isotope densities in samples and objects, while also providing contrast through rotational and translational molecular dynamics. These parameters are probed not only in magnetic resonance spectroscopy and imaging but also in nondestructive materials testing by mobile stray‐field NMR whose unique perks are valuable in cultural heritage studies. We present recent progress in the analysis of cultural heritage with mobile 1H NMR stray‐field sensors, for which the detection zone is outside of the NMR magnet. Prominent applications include the analysis of stratigraphies in paintings and frescoes, and the assessment of material states changing under the impact of aging, conservation and restoration. View Show abstract ... Painted surfaces including wood, stone,a nd canvas,a re prominent objects where mobile NMR sensors can help unravel their history and optimize conservation and restora- tion strategies.T he flat sensitive slice of the NMR-MOUSE combined with the portability of the sensor are valuable assets for mapping and characterizing thin-layer stratigraphy across depth ranges of up to 25 mm. [35][36][37][38] Wall paintings and frescoes are particularly unique in the sense that the stratigraphy of their mortar base bears the signature of the craftsmen at the time of painting,a ltering,and restoring. ... Cultural Heritage Studies with Mobile NMR Article Mar 2018 Angew Chem Christian Rehorn Bernhard Bluemich Nuclear Magnetic Resonance (NMR) provides in‐situ information about selected isotope densities in samples and objects, while also providing contrast through rotational and translational molecular dynamics. These parameters are probed not only in magnetic resonance spectroscopy and imaging but also in nondestructive materials testing by mobile stray‐field NMR whose unique perks are valuable in cultural heritage studies. We present recent progress in the analysis of cultural heritage with mobile 1H NMR stray‐field sensors, for which the detection zone is outside of the NMR magnet. Prominent applications include the analysis of stratigraphies in paintings and frescoes, and the assessment of material states changing under the impact of aging, conservation and restoration. View Show abstract ... One of these contexts is represented by mobile Laboratories (i.e., mobile Labs). The reference architecture [103] consists of a physically constrained environment, a mobile room/laboratory that can be transported. Inside this laboratory thousands of heterogeneous sensors/actuators can be activated to analyze critical objects, where measurements are to be extremely precise, fast and repeated several times (for reproducibility test). ... Smart Portable Devices Suitable for Cultural Heritage: A Review Article Full-text available Jul 2018 SENSORS-BASEL Federica Valentini Andrea Calcaterra Simonetta Antonaroli Maurizio Talamo This article reviews recent portable sensor technologies to apply in the Cultural Heritage (CH) fields. The review has been prepared in the form of a retrospective description of the sensor’s history and technological evolution, having: new nanomaterials for transducers, miniaturized, portable and integrated sensors, the wireless transmission of the analytical signals, ICT_Information Communication Technology and IoT_Internet of Things to apply to the cultural heritage field. In addition, a new trend of movable tattoo sensors devices is discussed, referred to in situ analysis, which is especially important when scientists are in the presence of un-movable and un-tangible Cultural Heritage and Art Work objects. The new proposed portable contact sensors (directly applied to art work objects and surfaces) are non-invasive and non-destructive to the different materials and surfaces of which cultural heritage is composed. View Show abstract ... Unilateral NMR has been previously used to measure selfdiffusion in porous materials, polymers, and viscous materials. [19] In the case of paintings, the technique allows the determination of the stratigraphy [20] in ac ompletely non-invasive manner, providing am ethod to map the work of art in its entirety to determine possible locations where micro-samples may be removed. [21] HR-MAS NMR spectroscopy allows analysis of very small samples of soft matter. ... Water Diffusion and Transport in Oil Paints as Studied by Unilateral NMR and 1H High‐Resolution MAS‐NMR Spectroscopy Article Sep 2019 CHEMPHYSCHEM Nicholas Zumbulyadis Silvia A. Centeno Cecil Dybowski Valeria Di Tullio Heavy metal carboxylate degradation severely affects thousands of oil paintings. Relative humidity has been reported to accelerate the rate of the reactions. To evaluate its role further, water diffusion and molecular mobility of protons in linseed oil‐based lead white paints were studied by unilateral NMR and 1 H HRMAS spectroscopy. The results indicate that exposure to high %RH for relatively long times affects the dynamics of the oil paint’s mobile fraction and that the effect is more pronounced as the thickness of the film increases. It was found that the paint can absorb appreciable amounts of water and has a porosity of approximately 6% available for the diffusion of water, for which a regime of restricted diffusion was observed. Furthermore, the presence of bound and free‐moving water, due to the possible formation of hydrated ionic groups clusters, supports the hypothesis of a polymeric/ionomeric network, as well as regions of essentially water free to move as in the bulk. The findings allow a better understanding of the role of water as a factor activating the degradation process in linseed oil‐based lead white paints. View Show abstract ... an NMR depth profile can detect, non-invasively and in situ, the multi-layered structure of a painting. In recent years, Presciutti et al. [41] reported the first NMR stratigraphy collected in a wooden painting dating from the 15th century. The profile encodes the intensity of the 1 H NMR signal as a function of the depth scanned, recognizing layers according to their hydrogen content. ... New Insights to Characterize Paint Varnishes and to Study Water in Paintings by Nuclear Magnetic Resonance Spectroscopy (NMR) Article Full-text available Apr 2020 Noemi Proietti Valeria Di Tullio Paintings are complex multi-layered systems made of organic and inorganic materials. Several factors can affect the degradation of paintings, such as environmental conditions, past restoration works and, finally, the type of painting technique and the art materials used over the centuries. The chemical–physical characterization of paintings is a constant challenge that requires research into and the development of novel analytical methodologies and processes. In recent years, solvents and water-related issues in paintings are attracting more attention, and several studies have been focused on analyzing the interaction between water molecules and the constitutive materials. In this study, recent applications applying different NMR methodologies were shown, highlighting the weakness and the strength of the techniques in analyzing paintings. In particular, the study of water and its diffusive interactions within wall and oil paintings was performed to prove how the portable NMR can be used directly in museums for planning restoration work and to monitor the degradation processes. Furthermore, some preliminary results on the analysis of varnishes and binders, such as linseed oil, shellac, sandarac and colophony resins, were obtained by 1H HR-MAS NMR spectroscopy, highlighting the weakness and strengths of this technique in the field of conservation science. View Show abstract ... Electron paramagnetic resonance (EPR) spectroscopy is one of a vast number of spectroscopic analytical techniques [1][2][3][4][5][6][7][8][9][10] used by art conservators, historians, and restorers to study paintings. EPR spectroscopy probes magnetic energy levels associated with unpaired electrons in matter, and is therefore useful for investigating paramagnetic, ferro/ferrimagnetic, and free radical containing pigments. ... The Noninvasive Analysis of Paint Mixtures on Canvas Using an EPR MOUSE Article Full-text available Mar 2020 Elizabeth A. Bogart Haley Wiskoski Matina Chanthavongsay Joseph Hornak Many artists create the variety of colors in their paintings by mixing a small number of primary pigments. Therefore, analytical techniques for studying paintings must be capable of determining the components of mixtures. Electron paramagnetic resonance (EPR) spectroscopy is one of many techniques that can achieve this, however it is invasive. With the recent introduction of the EPR mobile universal surface explorer (MOUSE), EPR is no longer invasive. The EPR MOUSE and a least squares regression algorithm were used to noninvasively identify pairwise mixtures of seven different paramagnetic pigments in paint on canvas. This capability will help art conservators, historians, and restorers to study paintings with EPR spectroscopy. View Show abstract ... The sublimation kinetics of CDD were studied both by NIR and NMR spectroscopies and a good agreement between the two employed techniques was demonstrated. The aim of this work was to broaden the investigation of the CDD + solvent system to include porous stone matrices, so as to describe its global disappearance process by means of the aforementioned, non-invasive analytical techniques [12][13][14][15][16][17][18][19][20][21][22]. ... A non-invasive investigation of cyclododecane kinetics in porous matrices by near-infrared spectroscopy and NMR in-depth profilometry Article May 2014 J CULT HERIT Chiara Anselmi Federica Presciutti Brenda Doherty Costanza Miliani In order to evaluate the effectiveness of cyclododecane (CDD) as a temporary protective coating and consolidating agent for fragile stone materials, this paper focuses on its physicochemical behaviour in terms of its penetration into porous matrices and subsequent sublimation. In particular, a near-infrared spectroscopy (NIR) and NMR in-depth profilometry study has been carried out by monitoring the evaporation/sublimation process of CDD solutions as a function of time. By means of this non-invasive multitechnique approach, the behavior of CDD both on the surface and inside the first millimeters of the stones has been adequately described. It has also been highlighted how the progression of CDD's disappearance within different stones is affected by both substrate porosity and boiling point of the carrier solvent. These results demonstrate the potential of such a method of protocol for non-invasive in situ monitoring of the unconstrained sublimation process of this temporary protective agent. View Show abstract ... This approach is invasive, resulting in the destruction of the integrity of the painting. Various noninvasive and noncontact modalities which can provide in-situ quantitative information in depth, such as confocal X-ray fluorescence (with elemental distribution contrast) [85], femtosecond pump-probe microscopy (with molecular and structural constrast) [86], nuclear magnetic resonance (with 1 H abundance constrast) [87], and optical coherence tomography (with structural constrast) [88], are under active research. Although with micrometer-level high resolution, these methods have limited penetration in depth, or imply probing a small region of interest, as opposed to an extended area, and therefore, cannot generate a 3D global mapping of the layer structure of a painting [89]. ... TERAHERTZ IMAGING FOR NONDESTRUCTIVE EVALUATION AND MATERIAL CHARACTERIZATION A Dissertation Presented to The Academic Faculty Thesis Jun 2017 Junliang Dong Thanks to the emergence of powerful light sources and highly sensitive detectorsoperating in the terahertz (THz) spectral region, the traditional THz ‘gap’ (0.1-10THz) is shrinking fast nowadays. Recent advances in photonics and electronics enablesthe development of compact but sophisticated THz time domain spectroscopy (TDS)systems. Today, pulsed THz imaging based on THz-TDS systems is investigatedin many areas spanning from nondestructive evaluation (NDE), industrial qualitycontrol, medical imaging and security sectors to studies of fundamental physics andcultural heritage. Despite the on-going broad applications of THz imaging, a THz‘killer application’– a novel, innovative use in which THz imaging exhibits higherperformance than any other existing techniques, is still waiting to be clearly identified.Therefore, the research problems of this thesis aim at the exploration of the potentialof THz imaging in the fields of industry and cultural heritage conservation science,and developing theories and techniques to enhance the capabilities of THz imagingto solve practical problems in NDE and material characterization.The thesis is outlined as follows. View Show abstract ... The sublimation kinetics of CDD were studied both by NIR and NMR spectroscopies and a good agreement between the two employed techniques was demonstrated. The aim of this work was to broaden the investigation of the CDD + solvent system to include porous stone matrices, so as to describe its global disappearance process by means of the aforementioned, non-invasive analytical techniques [12][13][14][15][16][17][18][19][20][21][22]. ... Monitoring of optimized SERS active gel substrates for painting and paper substrates by unilateral NMR profilometry Article Jul 2014 J Raman Spectros Antonio Sgamellotti Brenda Doherty Federica Presciutti Costanza Miliani In order to realize a surface enhanced Raman spectroscopy (SERS) gel protocol with portable Raman instrumentation, this contribution oversees the optimization of a removable SERS active methylcellulose gel and the applicability of an innovative gelatin substrate. Analytical evaluations by non-invasive portable nuclear magnetic resonance (NMR) profilometry with regards to methylcellulose and gelatin film penetration and removal from an unvarnished painted surface and commercial dyed paper substrates have been carried out, respectively, following successful SERS measurements. Both gels have been specifically prepared in accordance to the substrate under exam so as to simultaneously permit sufficient surface interaction for Raman enhancements to be recorded with limited penetration into or subsequent damage on removal of the matrix under study. This work continues to bridge the gap towards non-invasive SERS measurements and in-situ SERS measurements. Copyright © 2014 John Wiley & Sons, Ltd. View Show abstract ... With unilateral NMR, the magnetic field is applied to one side of the object allowing measurements to be performed without any sampling, thereby preserving the integrity of the object under investigation. [27][28][29][30][31][32][33][34][35] This non-destructive and non-invasive technique was applied to evaluate the penetration depth of the treatment, its capability to impair water absorption, the presence of inhomogeneities caused by sharp variations of the amount of absorbed product, and how the treatment may change the open porosity and may affect water diffusion through the porous matrix. Exploiting the strong and constant field gradient generated by unilateral NMR sensor, diffusion measurements were carried out to obtain the average surface-to-volume ratio of pores and the degree of pores interconnection in untreated and treated tuffs. ... Unilateral NMR investigation of multifunctional treatments on stones based on colloidal inorganic and organic nanoparticles Article Jan 2015 Magn Reson Chem Mariacristina Cocca Roberto Avolio Maurizio Avella Valeria Di Tullio Consolidation and protection are among the most important treatments usually carried out in conservation of stone artifacts and monuments. In this paper, portable unilateral NMR and conventional techniques were used for investigating new multifunctional treatments based on tetraethoxysilane, silica, and polytetrafluoroethylene nanoparticles. The study was carried out on a very complex and heterogeneous porous stone such as tuff. NMR study allowed to obtain detailed information on the penetration depth of treatments, the hydrophobic effect, and changes in the open porosity caused by treatments. Physical and chemical inhomogeneities between the impregnated layers of tuff and the layers underneath were also detected. The average pores radius and pores interconnection obtained from NMR diffusion measurements were used for the first time to compare effects of different consolidating and/or protective treatments on stone. Because unilateral NMR technique is neither destructive nor invasive, investigation of treatments can be also carried out and optimized directly on buildings and monuments of interest for Cultural Heritage. Copyright © 2014 John Wiley & Sons, Ltd. View Show abstract ... [11] The spin-spin decay related to a 1 H stratigraphy of a painting can suggest the presence of different layers constituted by different organic materials allowing for subsequent selective microsampling. [12][13][14] Moreover the spin-spin and spin-lattice relaxations can also be affected by the interaction ... A non-invasive NMR relaxometric characterization of the cyclododecane–solvent system inside porous substrates Article Jan 2015 Magn Reson Chem Federica Presciutti Brenda Doherty Chiara Anselmi Costanza Miliani With the aim of deepening the knowledge on the behavior of cyclododecane (CDD) as a temporary consolidant agent for weathered stones, NMR longitudinal and transverse relaxation decays have been exploited to follow the distribution of cyclododecane solutions into porous matrices. By measuring as function of time the relaxation decay constants of CDD solutions dropped onto porous supports, it has been possible to differentiate the step encompassing the solvent evaporation, which determines the consolidant migration within the matrix, from that governing the consolidant sublimation, which is related to the consolidation effectiveness over time. Copyright © 2014 John Wiley & Sons, Ltd. View Show abstract ... Following the 1 H NMR method already described in our previous paper [3], stratigraphic determinations were carried out in situ in a fully non-invasive way. The method encodes the amplitude of the 1 H NMR signal as a function of the depth scanned [6][7][8][9] allowing us to discriminate and visualize different layers made of different hydrogencontaining materials. ... A Multi-Analytical study of ancient nubian detached mural paintings Article Oct 2015 MICROCHEM J Noemi Proietti Valeria Di Tullio Federica Presciutti Donatella Capitani View A Miniaturized NMR-MOUSE with a High Magnetic Field Gradient (Mini-MOUSE) Article Dec 2014 APPL MAGN RESON Dirk Oligschläger Stefan Glöggler Jan Watzlaw Bernhard Bluemich Mobile nuclear magnetic resonance sensors still suffer from relatively high weight and large dimensions, although they are already considerably smaller than superconducting high-field magnets. Application of such sensors for an accurate analysis of rigid materials and thin layers is limited by the echo time of the radiofrequency (rf) coil and the spatial resolution of the sensor. This study presents the construction of a miniaturized NMR-MOUSE® that is reduced to about 90 % in volume and weight compared to a standard Profile NMR-MOUSE®. Thanks to the short dead time of 4 µs of the micro-structured rf coil, short transverse relaxation times of rigid and dry materials can be determined with improved accuracy. Furthermore, it is possible to record depth profiles with high resolution. The large magnetic field gradient of the new set-up leads to enhanced diffusion contrast. View Show abstract Characterization of aging and solvent treatments of painted surfaces using single-sided NMR Article Jan 2015 Magn Reson Chem Gwendoline Fife Bascha Stabik Allison E. Kelley Tyler Meldrum Typical experiments conducted with single-sided NMR are incapable of unique chemical identification and, thus, often rely on comparative measurements in scientific study. However, cultural heritage objects have unique natures and histories, making a genuine ‘control’ sample a rarity and complicating many scientific investigations. In this paper, we present some comparative results enabled by such a rare, control sample. Two paintings, The Dinner and The Dance from the 1616 set Pipenpoyse Wedding, were made by the same artist with indistinguishable materials and techniques. However, despite their shared history, The Dinner has undergone varnishing and subsequent varnish removal multiple times, whereas The Dance has not. NMR measurements on these two paintings show the effect of organic-solvent-based treatments on the stiffness of the paintings as measured by T2,eff, supporting visual and tactile observations that The Dinner is stiffer throughout its thickness than The Dance, probably due to ingress of natural resins and organic solvents into the paint and ground layers. In addition to a comparative analysis of these two paintings, initial experiments to compare solvent penetration with different varnish removal methods are described. Model canvas painting samples were treated with solvent in two ways—with free solvent on a swab and with cellulose gel thickened solvent in a tissue. Both treatment methods cause a measurable change in T2,eff; however, the thickened-solvent method affects a narrower region of the model than does the free solvent. Copyright © 2014 John Wiley & Sons, Ltd. View Show abstract Mobile Nuclear Magnetic Resonance Chapter Jun 2012 Ernesto Danieli Bernhard Blümich Federico Casanova In order to make NMR available for applications that require moving the NMR equipment outside of the laboratory, several research groups have engaged in developing magnets and radiofrequency probes suitable for in situ measurements. This article summarizes the advances reported in the field of mobile NMR within the last decade. In particular, emphasis is placed on the challenges posed by the hardware while optimizing compact sensors when specific methods, such as relaxation, imaging, or spectroscopy, need to be implemented. Since the design of mobile systems is driven by the target application, the tools are engineered in view of the optimum compromise between portability and sensitivity among the configurations that generate the required magnetic field profile. This review covers the most relevant methodologies available for sample characterization within mobile NMR and describes the steps taken to optimize the sensors.Keywords:mobile NMR;single-sided NMR;permanent magnets;magnet design;Halbach magnets View Show abstract Book of Abstracts of the 3rd International Seminar and Workshop on Emerging Technology and Innovation for Cultural Heritage "Advanced Technology for Diagnosis, Preservation and Management of Historical and Archaeological Parchment, Leather and Textile Artefacts" (ETICH 2014) Book Full-text available Oct 2014 Ed. Andrea Bernath Irina Petroviciu Elena Badea The International Seminar and Workshop on Emerging Technology and Innovation for Cultural Heritage (ETICH) is dedicated to the natural connection between science and conservation. The main aim of ETICH is to bring together conservators, restorers, conservation scientists, chemists, physicians, engineers, teachers and show how interdisciplinary work across a broad range of discipline is contributing to the conservation and sustainable preservation of our cultural heritage. In the last decades the booming developments in chemical, physical and biological science, but also in the fields of electronics and computer sciences, nanomaterials and nanotechnologies has brought us new instruments and methods of great perfection, which present new horizons in the analysis, diagnosis and protection of historical and cultural objects and artefacts. ETICH 2014 is the third edition after previous symposia organised in collaboration with the National Museum of Romania History in 2012 and Romanian Academy Library in 2013, and focusses on advanced technologies for diagnosis, preservation and management of historical and archaeological parchment, leather and textile artefacts. The need for full interdisciplinary participation of professionals in the conservation and restoration of cultural heritage has been universally recognised. We thus hope that the 2014 ETICH edition will particularly provide an international platform for presentation and discussion and on how to effectively integrate scientific research outcomes with preservation practice. The 2014 Seminar and Workshop is jointly organized by the National Research and Development Institute for Textile and Leather (INCDTP), ICPI Division, Bucharest, Romanian Association Science and Cultural Heritage in Connection (i-CON) and Training Centre for Conservators and Restorers (CePCoR), ASTRA National Museum Complex (CNM ASTRA), Sibiu. View Show abstract Miniaturized multi-coil arrays for functional planar imaging with a single-sided NMR sensor Article Feb 2015 Sören Lehmkuhl Dirk Oligschläger Jan Watzlaw Bernhard Bluemich Nowadays most low-field NMR sensors, such as the single-sided Profile NMR-MOUSE®, still suffer from poor sensitivity, either resulting from low magnetic field strengths and correspondingly low NMR frequencies, or lack of sensitivity. Generally, micro-coils can improve sensitivity, but due to their small size, and thus small inductance, they are mainly used for high-field NMR. Their main application field is parallel imaging, where those coils are typically assembled to receive-only coil-arrays and increase the field-of-view. Prominent signal combination techniques such as GRAPPA and SENSE are used to combine the spatially independent NMR signals to images in order to increase acquisition speed. A decisive disadvantage of today's single-sided NMR probes is the limited accessibility for NMR imaging. Although it is possible to use flat gradient coils on top of the NMR-MOUSE® to apply imaging techniques, such images can only be recorded with very long acquisition times, excluding the NMR-MOUSE® for lateral imaging of time-dependent processes. In this study sensitivity improved micro-structured RF coils, optimized for low frequencies, and correspondingly arrays of these coils, were employed to improve sensitivity and gave access to lateral spatial resolution within the sensitive plane at several observation points at the same time. Recently developed three- and four-coil arrays were combined with a Profile NMR-MOUSE® and characterized in terms of coil coupling, noise correlation and signal combination. The three-coil array was used for lateral imaging of moisture transport in travertine rock samples and to study the one-dimensional drying of paint. Copyright © 2015 Elsevier Inc. All rights reserved. View Show abstract Hyphenated low-field NMR techniques: combining NMR with NIR, GPC/SEC and rheometry: Hyphenated low-field NMR techniques Article Apr 2015 Magn Reson Chem Volker Räntzsch Manfred Wilhelm Gisela Guthausen Hyphenated low-field NMR techniques are promising characterization methods for online process analytics and comprehensive offline studies of soft materials. By combining different analytical methods with low-field NMR, information on chemical and physical properties can be correlated with molecular dynamics and complementary chemical information. In this review, we present three hyphenated low-field NMR techniques: a combination of near-infrared spectroscopy and time-domain NMR (TD-NMR) relaxometry, online (1) H-NMR spectroscopy measured directly after size exclusion chromatographic (SEC, also known as GPC) separation and a combination of rheometry and TD-NMR relaxometry for highly viscous materials. Case studies are reviewed that underline the possibilities and challenges of the different hyphenated low-field NMR methods. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd. View Show abstract Development of NMR: Solid-State NMR and Materials Science, Post 1995 Chapter Jun 2012 Jeffrey A. Reimer During the period 1995-2011 the sub-discipline of solid-state NMR grew enormously as represented by more than 30,000 publications, numerous conferences, and a burgeoning population of young researchers. This article seeks to summarize the trends of these researches in the area of materials chemistry, engineering, and physics. These trends are found to be based upon three pillars: a strong and evolving base of fundamental science, a clear connection to emerging computation and communication technologies, and the perspicacity of researchers in the fields of materials science.Keywords:solid-state NMR;materials;instrumentation;portable NMR;computation;theory;sensitivity;quadrupolar;dipolar;chemical shift View Show abstract Single-Sided Stray-Field NMR Profiling Using Chirped Radiofrequency Pulses Article Aug 2015 APPL MAGN RESON Leah B. Casabianca Yifat Sarda Elad Bergman Lucio Frydman Single-sided nuclear magnetic resonance (NMR) scanners find increased use in applications where non-destructive measurements are needed. These single-sided scanners are characterized by a weak magnetic field and a large stray magnetic field gradient. These characteristics make these scanners suitable for determining a sample’s proton density profile, or for mapping NMR properties such as T 1, T 2 or diffusivity as a function of distance. The strong stray-field gradient generated by these magnets dictates a need for relatively high transmission/reception bandwidths, even when thin slices are involved. Consequently, scanning a large volume demands multiple separate measurements, associated with long scan times, potential inaccuracies associated with mechanical misplacements and limitations in tackling certain in vivo or dynamic systems. This work explores the consequences of replacing the hard pulses in the usual multi-echo sequence used in this kind of scanner, with frequency-swept (chirped) pulses. It was found that, under identical echo times and number of echoes, peak power-limited cases like the ones usually involved in these setups endow chirped-pulse sequences with a higher sensitivity than their square-pulse counterparts. Furthermore, data can be extracted in this manner faster; it can also be measured from larger slabs following a single excitation, thereby avoiding the need for multiple mechanical motions of the scanner/sample. Still, at least with the system hereby assayed, hardware limitations prevented us from utilizing equally short echo times for square- as well as chirped-pulse implementations. Given the shorter echo delays that could be used in the square-pulse versions, optimal acquisitions ended up endowing the latter with the best overall sensitivity defined as signal intensity per unit acquisition time. Potential bypasses of this limitation are briefly discussed. View Show abstract Single-sided NMR Article Jan 2011 Federico Casanova Juan Perlo Bernhard Blümich Since its discovery in 1945 [1, 2], nuclear magnetic resonance (NMR) has developed into an inexhaustible research field. It is exploited in several areas in physics, chemistry, biology, and medicine to extract unique information at the molecular level [3–8]. In chemistry, for example, it is considered to be one of the most powerful analytical tools to elucidate molecular structure, and in medicine it is routinely used for diagnostic imaging. Driven by the fact that sensitivity and spectral resolution increase with the magnetic field strength and homogeneity, magnets are built larger and larger over the years. Today, magnets are heavy and static devices installed in special NMR laboratories designed to shield electromagnetic interference and reduce magnetic field distortions in order to provide ideal experimental conditions (Fig. 1.1a). Besides the fact that samples of interest must be taken to the magnet, they must fit into the limited space available in the bore of the magnet. These issues are certainly a limitation when arbitrarily large samples require non-destructive analysis. View Show abstract High resolution spectroscopic mapping imaging applied in situ to multilayer structures for stratigraphic identification of painted art objects Conference Paper Full-text available Apr 2016 G. Karagiannis The development of non–destructive techniques is a reality in the field of conservation science. These techniques are usually not so accurate, as the analytical micro–sampling techniques, however, the proper development of soft–computing techniques can improve their accuracy. In this work, we propose a real–time fast acquisition spectroscopic mapping imaging system that operates from the ultraviolet to mid infrared (UV/Vis/nIR/mIR) area of the electromagnetic spectrum and it is supported by a set of soft–computing methods to identify the materials that exist in a stratigraphic structure of paint layers. Particularly, the system acquires spectra in diffuse–reflectance mode, scanning in a Region-Of-Interest (ROI), and having wavelength range from 200 up to 5000 nm. Also, a fuzzy c–means clustering algorithm, i.e., the particular soft–computing algorithm, produces the mapping images. The evaluation of the method was tested on a byzantine painted icon. View Show abstract Applications in Material Science and Cultural Heritage Chapter Jan 2011 J. Kolz The diversity of available techniques has made magnetic resonance a valuable tool in medicine, in chemistry, as well as in material science [1–3]. In spite of the complexity of obtaining high-resolution spectra and the lower sensitivity compared to NMR with superconducting magnets this is also true for single-sided NMR, particularly considering that the technique is truly non-destructive due to the open geometry of the sensor [4, 5]. The first U-shaped sensor was conceived to View Show abstract Nondestructive Testing of Objects from Cultural Heritage with NMR Chapter Jun 2018 Maria Baias Bernhard Blümich Our world heritage is constantly facing the risk of being lost, either to severe weather conditions, chemical or biological attack, mishandling by conservators, inappropriate storage conditions, or even destruction by war. Science can provide the necessary tools for analyzing the objects of cultural heritage, assessing their state of conservation, and proposing suitable methods and strategies for preserving them for future generations. Nondestructive testing by nuclear magnetic resonance (NMR) in this area of research is relatively new. It was made possible by the development of portable single-sided NMR sensors capable of recording NMR signals from samples that are exterior to the magnet. Nondestructibility and mobility are the two main features identifying mobile NMR as an essential tool for cultural heritage research. © Springer International Publishing AG, part of Springer Nature 2018. View Show abstract Identification of complex structures of paintings on canvas by NMR: Correlation between NMR profile and stratigraphy Article May 2020 MAGN RESON CHEM Leonardo Brizi Villiam Bortolotti Giulia Marmotti Mara Camaiti 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 over‐paintings, 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. NMR profiling, often named NMR stratigraphy, is an NMR relaxometry technique applied by single‐sided portable devices developed to overcome the disadvantages of micro‐invasive 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 T 2 quasi‐continuous distributions, and the results compared with standard stratigraphic cross‐sections analysis. Combining signal intensity and T 2 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 non‐uniform 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 non‐destructive method for analyzing paintings on canvas. View Show abstract NMR relaxometry of oil-paint binders Article Full-text available Mar 2020 MAGN RESON CHEM Franziska Busse Markus Küppers Christian Rehorn Bernhard Blümich Mobile nuclear magnetic resonance (NMR) is a flexible technique for nondestructive characterization of water in plants, the physical properties of polymers, moisture in porous walls or the binder in paintings by relaxation measurements. NMR relaxation data report material properties and therefore can also help to characterize the state of tangible cultural heritage. In this work, we discuss the relaxation behavior in two series' of naturally aged paint mock‐up samples. First, paints with different pigment concentrations were prepared and investigated in terms of the longitudinal and transverse relaxation‐time distributions. We document the evolution of both relaxation time distributions during the initial drying stage and demonstrate the heightened importance of transverse over longitudinal relaxation measurements. Second, we observe non‐linear dependences of the relaxation times on the pigment concentration in a typical oil binder. Third, in a study of naturally aged paint samples prepared in the years between 1914 and 1951 and subsequently aged under controlled conditions, we explore the possibility of determining the age of paintings using partial least square regression (PLS) by fitting T1‐T2 data with the sample age. Our results suggest some correlation, albeit with significant scatter. Estimating the age of a painting stored under unknown conditions from NMR relaxation data is therefore not feasible, as the cumulative effects of light irradiation, humidity, and biological degradation further obfuscate the chemical and physical impact of aging on the relaxation times in addition to the impact of pigment concentration. View Show abstract Production of highly concentrated and hyperpolarized metabolites within seconds in high and low magnetic fields Article Full-text available Oct 2019 PHYS CHEM CHEM PHYS Sergey Korchak Meike Emondts Salvatore Mamone Stefan Glöggler Hyperpolarized metabolites are very attractive contrast agents for in vivo magnetic resonance imaging studies enabling early diagnosis of cancer, for example. Real-time production of concentrated solutions of metabolites is a desired goal that will enable new applications such as the continuous investigation of metabolic changes. To this end, we are introducing two NMR experiments that allow us to deliver high levels of polarization at high concentrations (50 mM) of an acetate precursor (55% 13C polarization) and acetate (17% 13C polarization) utilizing 83% para-state enriched hydrogen within seconds at high magnetic field (7 T). Furthermore, we have translated these experiments to a portable low-field spectrometer with a permanent magnet operating at 1 T. The presented developments pave the way for a rapid and affordable production of hyperpolarized metabolites that can be implemented in e.g. metabolomics labs and for medical diagnosis. View Show abstract The MR Cap: A single‐sided MRI system designed for potential point‐of‐care limited field‐of‐view brain imaging Article Jun 2019 MAGN RESON MED Patrick C. McDaniel Clarissa Zimmerman Cooley Jason P Stockmann Lawrence L Wald Purpose: The size, cost, and siting requirements of conventional MRI systems limit their availability and preclude usage as monitoring or point-of-care devices. To address this, we developed a lightweight MRI for point-of-care brain imaging over a reduced field of view (FOV). Methods: The B0 magnet was designed with a genetic algorithm optimizing homogeneity over a 3 × 8 × 8 cm FOV and a built-in gradient for slice selection or readout encoding. An external pair of gradient coils enables phase encoding in the other two directions and a radiofrequency (RF) coil provides excitation and detection. The system was demonstrated with high-resolution 1D "depth profiling" and 3D phantom imaging. Results: The lightweight B0 magnet achieved a 64-mT average field over the imaging region at a materials cost of <$450 USD. The weight of the magnet, gradient, and RF coil was 8.3 kg. Depth profiles were obtained at high resolution (0.89 mm) and multislice rapid acquisition with refocused echoes (RARE) images were obtained with a resolution ~2 mm in-plane and ~6-mm slice thickness, each in an imaging time of 11 min. Conclusion: The system demonstrates the feasibility of a lightweight brain MRI system capable of 1D to 3D imaging within a reduced FOV. The proposed system is low-cost and small enough to be used in point-of-care applications. View Show abstract Advanced Characterization Techniques, Diagnostic Tools and Evaluation Methods in Heritage Science Book Jan 2018 David M. Bastidas Emilio Cano This book details the application of advanced characterisation techniques and diagnostic tools to heritage science, including the evaluation of heritage assets’ condition, their preservation and restoration. It examines the use of electrochemical techniques in conservation science, with a particular focus on how to solve problems in taking on-site measurements. Specifically, it introduces readers to a new gel polymer (GPE) electrochemical cell developed by the authors for the characterisation of metallic heritage objects. Other techniques used to characterise and monitor reinforced concrete objects in more modern buildings are also covered, including non-destructive electrochemical techniques that allow steel corrosion to be assessed in these structures, and in those that are used to protect and repair such buildings. The usefulness of the NMR-Mouse nuclear magnetic resonance sensor in the assessment and preservation of softer heritage materials, such as wood, parchment, bone, and painted walls, is covered, as well as Infrared reflectography for examining paintings and laser cleaning for restoring them. The book introduces ultra-High Performance Liquid Chromatography (u-HPLC) with a diode-array (DAD) and mass–mass (MS-MS) quadruple time-of-flight spectroscopy (QTOF). This new technique can be applied to the analysis and identification of natural and synthetic organic pigments and its use is demonstrated in several case studies. This book provides a rigorous scientific grounding in the application of state-of-the-art techniques in heritage science and conservation, and offers a practical handbook for practitioners. View Show abstract Concepts and Applications of the NMR-MOUSE Chapter Jan 2018 Bernhard Blümich The NMR-MOUSE is a portable magnetic resonance imaging device employed for non-destructive testing of hydrogen-containing materials. Following an introduction to NMR and the NMR-MOUSE, the use of the device for heritage studies is illustrated with examples concerning mummies, easel paintings and frescoes. View Show abstract Mobile and Compact NMR Chapter Jan 2018 Bernhard Blümich View Solid-state NMR for the study of Asger Jorn’s paintings Article Nov 2015 Microchem J Cindie Kehlet Filiz Kuvvetli Amelia Catalano Jens Dittmer In this work, we explore the potential of a recent NMR technology, requiring one to two orders of magnitude less sample quantity than conventional solid-state NMR, for the study of oil paintings. The aim is the detection of changes on the molecular level that may be related to the degradation of the paint. Our sample is a small paint fragment that has flaked off the canvas of Asger Jorn's work Maske from 1945, and an approximatively one-year-old zinc white reference sample. In addition to the expected signals stemming from products of the curing process, we observe chemical shifts corresponding to carboxylates indicating de-esterification and saponification. The advantage of using solid-state NMR is the possibility to study the entire sample rather than the small extractable mobile fraction. Fast spinning in conjunction with filtering techniques allows for the acquisition of 1H spectra of the mobile fraction in order to characterize it in its original environment. This could be all the more important as some hypotheses say that the loss of this mobile phase, acting as a plasticizer, is responsible for the degradation of the paint. View Show abstract Photoacoustic signal attenuation analysis for the assessment of thin layers thickness in paintings Article Full-text available Mar 2018 J APPL PHYS George Tserevelakis Alice Dal Fovo K. Melessanaki Giannis Zacharakis This study introduces a novel method for the thickness estimation of thin paint layers in works of art, based on photoacoustic signal attenuation analysis (PAcSAA). Ad hoc designed samples with acrylic paint layers (Primary Red Magenta, Cadmium Yellow, Ultramarine Blue) of various thicknesses on glass substrates were realized for the specific application. After characterization by Optical Coherence Tomography imaging, samples were irradiated at the back side using low energy nanosecond laser pulses of 532 nm wavelength. Photoacoustic waves undergo a frequency-dependent exponential attenuation through the paint layer, before being detected by a broadband ultrasonic transducer. Frequency analysis of the recorded time-domain signals allows for the estimation of the average transmitted frequency function, which shows an exponential decay with the layer thickness. Ultrasonic attenuation models were obtained for each pigment and used to fit the data acquired on an inhomogeneous painted mock-up simulating a real canvas painting. Thickness evaluation through PAcSAA resulted in excellent agreement with cross-section analysis with a conventional brightfield microscope. The results of the current study demonstrate the potential of the proposed PAcSAA method for the non-destructive stratigraphic analysis of painted artworks. View Show abstract Mobile NMR: An essential tool for protecting our cultural heritage Article Oct 2016 MAGN RESON CHEM Maria Baias What is "cultural heritage"? Is it simply our legacy of physical artifacts – or is it our collective legacy as human societies – how we want to be remembered by future generations? With time, negligence, and even military conflict working to erase the past, we must ask: Can a better understanding of our shared heritage assist us in addressing cultural differences in the present day? And how can science both help us understand the historic record and work to preserve it? In this perspective article we examine an emerging scientific method, mobile nuclear magnetic resonance, that can help us examine in a non-invasive way important objects and sites of our cultural heritage. Following these investigations one can envisage ways for protecting our global heritage for future generations. For this purpose we examine how this method can be used to non-destructively explore historical artifacts, which can lead to understanding the science behind the creation of these treasured items – paintings, frescoes, parchments, historical buildings, musical instruments, ancient mummies, and other artifacts. This perspective article follows few relevant examples from the scientific literature where mobile NMR has been applied in a non-invasive way to analyze objects of cultural heritage. One can envision possible future advancements of this technique and further applications where portable NMR can be used for conservation of cultural heritage. View Show abstract Effect of pigment concentration on NMR relaxometry in acrylic paints Article May 2020 MAGN RESON CHEM Mary T. Rooney Tyler Meldrum Acrylic emulsion paint is among the most common media employed by 20th century artists. Since early acrylic paintings have begun to require the attention of conservators, scientists are working to characterize the properties of these paints to facilitate conservation efforts. In this study, we report an investigation of the physical and chemical properties of acrylic emulsion paints using single‐sided NMR in conjunction with gloss measurements and scanning electron microscopy‐energy dispersive spectrometry. Combining the data from these techniques gives insight into pigment‐base interactions and the acrylic curing process, showing that as pigment concentration is increased in paints, the amount of acrylic base adsorbed to pigment particles increases, resulting in films with differing relaxation times. This research both emphasizes and contextualizes the utility of NMR relaxometry in studying cultural heritage objects, and prompts further study into the effects of pigment concentration on the curing and conservation of paint films. View Show abstract Investigation of stratigraphic mapping in paintings using micro-Raman spectroscopy Conference Paper Full-text available Apr 2016 G. Karagiannis Georgios Apostolidis In this work, microRaman spectroscopy is used to investigate the stratigraphic mapping in paintings. The objective of mapping imaging is to segment the dataset, here spectra, into clusters each of which consisting spectra that have similar characteristics; hence, similar chemical composition. The spatial distribution of such clusters can be illustrated in pseudocolor images, in which each pixel of image is colored according to its cluster membership. Such mapping images convey information about the spatial distribution of the chemical substances in an object. Moreover, the laser light source that is used has excitation in 1064 nm, i.e., near infrared (NIR), allowing the penetration of the radiation in deeper layers. Thus, the mapping images that are produced by clustering the acquired spectra (specifying specific bands of Raman shifts) can provide stratigraphic information in the mapping images, i.e., images that convey information of the distribution of substances from deeper, as well. To cluster the spectra, unsupervised machine learning algorithms are applied, e.g., hierarchical clustering. Furthermore, the optical microscopy camera (×50), where the Raman probe (B and WTek iRaman EX) is plugged in, is attached to a computerized numerical control (CNC) system which is driven by a software that is specially developed for Raman mapping. This software except for the conventional CNC operation allows the user to parameterize the spectrometer and check each and every measurement to ensure proper acquisition. This facility is important in painting investigation because some materials are vulnerable to such specific parameterization that other materials demand. The technique is tested on a portable experimental overpainted icon of a known stratigraphy. Specifically, the under icon, i.e., the wavy hair of “Saint James”, can be separated from upper icon, i.e., the halo of Mother of God in the “Descent of the Cross”. View Show abstract An analytical renaissance Article Feb 2010 CHEM IND-LONDON Michael Gross View Unilateral magnetic resonance Article Jan 2013 J.C. García In just a few decades Nuclear Magnetic Resonance (NMR) has become an important tool in almost all areas of human development. In this context, Unilateral Magnetic Resonance (UMR) has emerged in recent years as a powerful technique to explore samples of arbitrary size. In UMR the desired magnetic field is generated in a remote volume outside the magnet, which means inhomogeneous magnetic field. New magnet designs have been developed and applied in diverse fields such as down-hole oil well logging, characterization of food products, medical applications, material analysis, artwork preservation and investigation of plants and soils. Nevertheless, because of the advantages and capabilities of this method, new applications are continually being developed. This work introduces the particularities of NMR in inhomogenous fields and makes a review of the most important works developed in UMR. Magnet approaches and new applications are discussed. View Show abstract Mobile depth profiling and sub-surface imaging techniques for historical paintings—Review Article Article Jul 2013 SPECTROCHIM ACTA B Matthias Alfeld José A. C. Broekaert Hidden, sub-surface paint layers and features contain valuable information for the art-historical investigation of a painting's past and for its conservation for coming generations. The number of techniques available for the study of these features has been considerably extended in the last decades and established techniques have been refined. This review focuses on mobile non-destructive subsurface imaging and depth profiling techniques, which allow for the in-situ investigation of easel paintings, i.e. paintings on a portable support. Among the techniques discussed are: X-ray radiography and infrared reflectography, which are long established methods and are in use for several decades. Their capabilities of element/species specific imaging have been extended by the introduction of energy/wavelength resolved measurements. Scanning macro-X-ray fluorescence analysis made it for the first time possible to acquire elemental distribution images in-situ and optical coherence tomography allows for the non-destructive study the surface paint layers in virtual cross-sections. These techniques and their variants are presented next to other techniques, such as Terahertz imaging, Nuclear Magnetic Resonance depth profiling and established techniques for non destructive testing (thermography, ultrasonic imaging and laser based interference methods) applied in the conservation of historical paintings. Next to selected case studies the capabilities and limitations of the techniques are discussed. View Show abstract Show more A Review of Nondestructive Characterization of Composites Using NMR Chapter Jan 1989 George A. Matzkanin Nuclear Magnetic Resonance (NMR) is a nondestructive evaluation technique useful for characterizing organic matrix composites and other polymer based materials. NMR depends on the interaction between the nuclear magnetic moment and a magnetic field and thus it is sensitive to localized field variations caused by molecular motions, changes in molecular or crystal structure, and chemical composition differences. Application of NMR to composites and polymers involves measurement of the hydrogen nucleus (proton) NMR signal. Fortunately, the proton NMR signal is very strong and easily measured. Much of the physical and chemical information available through the use of NMR is associated with the relaxation characteristics of the nuclear magnetic moments, which can be measured using pulsed NMR techniques. The energy exchange between nuclear moments and the surrounding lattice is characterized by the spin-lattice relaxation time, T1, while the energy exchange among nudear magnetic moments is described by the spin-spin relaxation time, T2. These relaxation times are very sensitive to molecular motions and structural changes and can be used to provide both qualitative and quantitative information on the dynamic environment in which the nuclei are located. For application to composites and polymers, hydrogen NMR has been used to characterize water absorption, molecular diffusion, environmental degradation, aging, degree of cure, and modulus variations. View Show abstract A new tool for painting diagnostics: Optical coherence tomography Article Jul 2006 OPT SPECTROSC+ Tito Arecchi Marco Bellini C. Corsi A. Tortora Nondestructive techniques have seen successful growth in the last few years, and, among them, optical ones are widespread and extremely well received in the field of painting diagnostics because of their effectiveness and safety. At present, many techniques for nondestructive investigations of paintings are available; nevertheless, none of them is suitable for a quantitative characterization of varnish. However, varnish removal, either partial or complete, is a fundamental part of the cleaning process, which is an essential step in painting conservation. This critical process has been carried out, up to now, without the possibility of any non-destructive measurement for assessing the actual varnish thickness, but with microscopic observation of a detached microfragment. Optical coherence tomography (OCT) is a noninvasive technique that is well established for biomedical applications. In this work, we present a novel application of OCT to measure the varnish film thickness for painting diagnostics. View Show abstract Non-invasive in-situ investigations versus micro-sampling: A comparative study on a Renoirs painting Article Dec 2007 APPL PHYS A-MATER Costanza Miliani Francesca Rosi Aviva Burnstock Antonio Sgamellotti In this paper, a multi-technique in-situ non-invasive approach has been followed for the study of the materials used for a painting by Pierre-Auguste Renoir, “A woman at her toilette”. The study was carried out using five portable spectroscopic techniques, namely X-ray fluorescence, mid-infrared reflectance spectroscopy, near infrared reflectance spectroscopy, and UV-Vis spectroscopy in absorption and emission. The painting was selected as a case study because it was examined in advance of the current investigation using conventional micro-sampling techniques. This provided the opportunity to evaluate potential and limitations of the non-invasive approach to the complex case of the modern painting. View Show abstract The NMR MOUSE, a mobile universal surface explorer Article Sep 1996 J Magn Reson G. Eidmann R. Savelsberg Peter Blümler Bernhard Blümich View Non-invasive identification of surface materials on marble artifacts with fiber optic mid-FTIR reflectance spectroscopy Article Aug 2006 Camilla Ricci Costanza Miliani Bruno Brunetti Antonio Sgamellotti Research work using a compact and portable fiber optic mid-infrared reflectance spectrometer has been carried out to study surface materials on marble, first on laboratory reference models and then on historical objects. The laboratory research has shown that the complex optical reflectance phenomena of layered samples can be interpreted in terms of the nature of the compounds present (sulfates, oxalates, phosphates, resins, waxes and proteins were studied) even with a very low signal overlapping with the strong carbonate reflectance. The portable instrument was used for in situ examination of the surface condition of two Italian marble works of art: the Deposizione dalla Croce by Benedetto Antelami in the Parma cathedral and the David by Michelangelo in the Galleria dell'Accademia in Firenze. View Show abstract Degradation of historical paper: Nondestructive analysis by the NMR-MOUSE Article May 2003 J MAGN RESON Bernhard Bluemich S. Anferova Shivam Sharma C Federici The NMR-MOUSE is a mobile sensor for single-sided NMR inspection of organic materials which takes advantage of the principles of magnetic resonance and inside-out-NMR. Historical books dating from the 17th century were measured at different points by positioning the NMR-MOUSE on the paper. Different degrees of paper degradation can be discriminated from the regularized inverse Laplace transform of the envelope of the acquired echo signals. For the first time the degradation of historical paper was characterized entirely nondestructively by NMR. As a contribution to current preservation efforts, NMR shows great promise for future use in damage assessment of historical documents. View Show abstract Monitoring degradation in paper: Non-invasive analysis by unilateral NMR. Part II Article Oct 2004 J MAGN RESON Noemi Proietti Donatella Capitani Enrico Pedemonte A.L. Segre High quality paper samples have been oxidized with a specific oxidant to reproduce one of the possible causes of the aging of paper. All samples have been characterized by 13C CP-MAS NMR spectroscopy. The artificial aging of paper has been monitored using a standard NMR relaxometer and the results have been compared with the corresponding data obtained using an unilateral NMR relaxometer. Experimental values obtained with both techniques are in agreement, demonstrating that unilateral NMR relaxometric measurements constitute a suitable non-invasive method for assessing the degradation process of cellulose-based materials. The sensitivity of the non-invasive NMR method allows the detection of degradation even at a very early stage. Effects due to the sample volume and to the penetration depth have been investigated. View Show abstract Profiles with Microscopic Resolution by Single-Sided NMR Article Oct 2005 J MAGN RESON Juan Perlo Federico Casanova Bernhard Bluemich A single-sided NMR sensor to produce depth profiles with microscopic spatial resolution is presented. It uses a novel permanent magnet geometry that generates a highly flat sensitive volume parallel to the scanner surface. By repositioning the sensitive slice across the object one-dimensional profiles of the sample structure can be produced with a space resolution better than 5 microm. The open geometry of the sensor results in a powerful testing tool to characterize arbitrarily sized objects in a non-destructive way. View Show abstract Fiber-Optic Fourier Transform Mid-Infrared Reflectance Spectroscopy: A Suitable Technique for in Situ Studies of Mural Paintings Article Apr 2007 APPL SPECTROSC Costanza Miliani Francesca Rosi Ilaria Borgia Antonio Sgamellotti A prototypical in situ noninvasive study of ancient mural painting materials has been carried out using an easily manageable fiber-optic Fourier transform mid-infrared (mid-FT-IR) reflectance spectrophotometer. The reported object of the study is the Renaissance fresco by Pietro Vannucci, called il Perugino, located in the church of Santa Maria delle Lacrime (1521, Trevi, Perugia Italy). For the first classification and interpretation of infrared spectra, principal components analysis was used. Spectral artifacts due to lacunas, restoration materials, or alteration products have been identified, as well as two different secco refinements bound in a tempera medium. For the characterization of inorganic pigments, mid-FT-IR spectra have been integrated with other data obtained through in situ X-ray fluorescence (XRF) elemental analysis. This complementary noninvasive approach led to the characterization of Perugino's pigments, even in the presence of complex mixtures. The mid-FT-IR noninvasive technique, in combination with XRF, is thus recommended as a valuable first approach for the examination of mural paintings, permitting the assessment of the execution technique as well as contributing to the evaluation of the conservation state. View Show abstract Jan 2007 F Miliani A Rosi B G Burnstock A Brunetti Sgamellotti Miliani, F. Rosi, A. Burnstock, B. G. Brunetti, and A. Sgamellotti, Appl. Phys. A: Mater. Sci. Process. 89, 849 2007. Jan 1996 R Eidmann P Salvelsberg B Blümler Blümich Eidmann, R. Salvelsberg, P. Blümler, and B. Blümich, J. Magn. Reson., Ser. A 122, 104 1996. Jan 2006 M Arecchi C Bellini R Corsi M Fontana L Materazzi A Pezzati Tortora Arecchi, M. Bellini, C. Corsi, R. Fontana, M. Materazzi, L. Pezzati, and A. Tortora, Opt. Spectrosc. 101, 23 2006. Jan 2004 D Proietti E Capitani B Pedemonte A L Blümich Segre Proietti, D. Capitani, E. Pedemonte, B. Blümich, and A. L. Segre, J. Magn. Reson. 170, 113 2004. Jul 2003 S Blümich S Anferova A L Sharma C Segre Federici Blümich, S. Anferova, S. Sharma, A. L. Segre, and C. Federici, J. Magn. Reson. 161, 204 2003. Jan 2005 F Perlo B Casanova Blümich Perlo, F. Casanova, and B. Blümich, J. Magn. Reson. 176, 64 2005. 11 B. Blümich, Essential NMR Springer, Berlin, 2005. Jan 2005 B Blümich B. Blümich, Essential NMR ͑Springer, Berlin, 2005͒. Recommendations Discover more about: Painting Project SICAMOR Francesca Benetti Valeria Di Tullio Donatella Capitani [...] Emiliano Carretti View project Article Non-invasive NMR profiling of painting layers January 2008 · Applied Physics Letters Federica Presciutti Juan Perlo Costanza Miliani [...] Antonio Sgamellotti In this work we demonstrate the potential of single-sided nuclear magnetic resonance �NMR� sensors to access deeper layers of paintings noninvasively by means of high-resolution depth profiles spanning several millimeters. The performance of the sensor in resolving painting structures was tested on models for which excellent agreement with microscopy techniques was obtained. The depth profiling ... [Show full abstract] NMR technique was used in situ to investigate old master paintings. The observation of differences in NMR relaxation times of tempera binders from these paintings and from artificially aged panels raises the possibility to differentiate between original and recently restored areas. Read more Looking for the full-text? You can request the full-text of this article directly from the authors on ResearchGate. Request full-text Already a member? Log in ResearchGate iOS App Get it from the App Store now. Install Keep up with your stats and more Access scientific knowledge from anywhere or Discover by subject area Recruit researchers Join for free LoginEmail Tip: Most researchers use their institutional email address as their ResearchGate login PasswordForgot password? Keep me logged in Log in or Continue with LinkedIn Continue with Google Welcome back! Please log in. Email · HintTip: Most researchers use their institutional email address as their ResearchGate login PasswordForgot password? 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