Publications by authors named "Roberto Senesi"
Article Synopsis
- The study measures the nuclear kinetic energies of hydrogen and oxygen in water molecules as they transition from solid to liquid at specific temperatures (270 K for solid and 276 K for liquid), using neutron Compton profiles in deep inelastic neutron scattering experiments.* -
- It finds similar total kinetic energy values per molecule in both phases (35.3 ± 0.8 kJ/mol for solid, 34.8 ± 0.8 kJ/mol for liquid), aligning with computer simulations and models that suggest minimal difference between the two states through a phase change.* -
- The small variance in nuclear kinetic energy across melting enables simplification in calculating neutron environmental doses in settings like high altitude or polar regions, suggesting that the
Article Synopsis
- - Neutron imaging is a powerful technique used in various applications that require strong penetration capabilities, especially for detecting specific elements and analyzing crystal structures.
- - Two notable methods are white-beam neutron imaging, which focuses on elements with high neutron attenuation, and energy-resolved Bragg edge imaging for studying crystal lattices.
- - The text emphasizes the potential of energy-selective neutron imaging to provide detailed molecular-specific information, highlighted by a practical example investigating molecular-hydrogen behavior in the HKUST-1 metal-organic framework.
Article Synopsis
- Boron-containing compounds like 4-borono-phenylalanine (BPA) are used in Boron Neutron Capture Therapy (BNCT) to target and destroy cancer cells via neutron irradiation, which triggers nuclear reactions in boron-rich materials.* -
- This study models the thermal neutron cross-section of BPA to examine how boron absorption competes with hydrogen scattering, aiming to optimize BNCT treatment by reducing the latter's effect.* -
- The findings indicate that fluorinated versions of BPA enhance neutron capture efficiency, offering a potential improvement for BNCT, while also facilitating monitoring and pharmacokinetic studies with fluorine-based imaging techniques.*
The increasing interest in stretchable conductive composite materials, that can be versatile and suitable for wide-ranging application, has sparked a growing demand for studies of scalable fabrication techniques and specifically tailored geometries. Thanks to the combination of the conductivity and robustness of carbon nanotube (CNT) materials with the viscoelastic properties of polymer films, in particular their stretchability, "surface composites" made of a CNT on polymeric films are a promising way to obtain a low-cost, conductive, elastic, moldable, and patternable material. The use of polymers selected for specific applications, however, requires targeted studies to deeply understand the interface interactions between a CNT and the surface of such polymer films, and in particular the stability and durability of a CNT grafting onto the polymer itself.
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- - This study explores the properties of methylammonium lead tribromide single crystals across different phases (orthorhombic, tetragonal, and cubic) using neutron scattering techniques, emphasizing the impact of vibrational energies on hydrogen nuclear kinetic energy.
- - It highlights that the tetragonal phase exhibits a higher Gaussian contribution to average nuclear kinetic energy compared to the cubic and orthorhombic phases, suggesting distinct vibrational behaviors in different structural phases.
- - The research confirms that vibrational modes in the orthorhombic phase align with results from powder samples, with only minor frequency differences noted when comparing to similar compounds (MAPbI), indicating consistent zero-point energies across the two perovskites. *
Article Synopsis
- * It employs 3σ and 10σ methods to analyze spectral intensities across specific energy-transfer ranges, highlighting the impact of the blank (instrument setup without analyte) on measurement accuracy, particularly with small sample sizes.
- * The findings indicate TOSCA can detect 128 μmol of elemental hydrogen and quantify 428 μmol in ZrH, providing valuable data for creating calibration curves and assessing instrument sensitivity for both TOSCA and the upcoming VESPA beam
Extra virgin olive oil (EVOO) is defined as a functional food as it contains numerous phenolic components with well-recognized health-beneficial properties, such as high antioxidant and anti-inflammatory capacity. These characteristics depend on their structural/conformational behavior, which is largely determined by intra- and intermolecular H-bond interactions. While the vibrational dynamics of isolated compounds have been studied in a number of recent investigations, their signal in a real-life sample of EVOO is overwhelmed by the major constituent acids.
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- The experimental neutron cross sections for all 20 standard amino acids were measured over a range of energies from 1 meV to 10 keV, using advanced calculation techniques.
- The dominant contribution to scattering comes from hydrogen atoms, and the results simplify the modeling of complex organic systems like proteins and tissues by averaging functional group contributions.
- These findings enhance transport simulations for medical applications, particularly in therapies such as boron neutron capture therapy and proton therapy, while also improving the accuracy of neutron scattering experiments on biological samples.
Article Synopsis
- The study investigates the hydrogen nuclear momentum distribution in biphenyl using deep inelastic neutron scattering, revealing that the potential affecting hydrogen is mainly harmonic and isotropic in nature.
- The findings support the central limit theorem, indicating that as the number of vibrational modes increases, the momentum distribution approaches a Gaussian function.
- Additionally, the research highlights a disparity between experimental and theoretical predictions of anisotropy in biphenyl due to complex interactions and structural disorder, while also showcasing an improved experimental setup for better data collection.
Article Synopsis
- * It is validated using INS measurements of ZrH from the TOSCA spectrometer and applied to the biological molecule l-lysine, ultimately enhancing the reliability of experimental benchmarks for theoretical calculations.
- * The study also covers self-shielding corrections based on neutron sample cross-section and presents how this data can be derived experimentally, making the algorithm accessible to the neutron research community through MANTID software.
Article Synopsis
- The study explores supercritical water using neutron scattering experiments and molecular dynamics simulations, focusing on hydrogen dynamics under high pressure and temperature conditions.
- It examines how vibrational motions, like bending and stretching, change as water transitions from a subcritical liquid to a supercritical gas-like state, analyzing these changes through a detailed spectral decomposition.
- The findings reveal that hydrogen bonds remain intact at elevated temperatures and indicate that the local hydrogen potential becomes less anisotropic in the supercritical phase due to more distorted hydrogen bonds, highlighting the interplay between intramolecular and intermolecular dynamics.
Article Synopsis
- The Mariana Trench, specifically the Challenger Deep, is an extreme environment where unique experiments on hydrogen nuclear dynamics in water were conducted under high pressure (1092 bars), low temperature (1 °C), and salinity (35 g/kg).
- Using deep inelastic neutron scattering at the VESUVIO spectrometer, researchers found that pressure increases the hydrogen nuclear mean kinetic energy, while ions in the water have the opposite effect.
- These findings support advanced simulations on hydrogen dynamics and may explain variations in isotopic fractionation values in the Challenger Deep compared to standard seawater.
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- - The study focuses on developing electrode arrays made from single-walled carbon nanotubes (SWCNT) attached to medium-density polyethylene (MD-PE) films for better brain monitoring technology known as brain-machine interface (BMI).
- - Researchers tested these SWCNT arrays in laboratory rats for two months, observing their ability to record stable and high-quality brain electrical activity (ECoG), as well as assessing their flexibility, stability, and biocompatibility.
- - The findings suggest that these flexible SWCNT-based electrodes have great potential for chronic use in monitoring epilepsy and could be valuable for neuroprosthetic applications due to their low impedance and adaptability to brain surface contours.
Article Synopsis
- Innovative conductors made from single wall carbon nanotubes (SWCNT) are developed for flexible and stretchable electronic applications without needing chemical modifications for stable integration with polymer films.
- The composite materials combine the biocompatibility of carbon nanotubes, their electrical conductivity, and the elastic properties of polymers, allowing for effective use in technology.
- Electrical testing shows promise for these materials in practical uses, demonstrated by a six-sensor grid recording brain activity in rats over three months.
Article Synopsis
- - Advances in Cultural Heritage research are focusing on a multidisciplinary approach that combines physical and chemical evaluations to understand artefacts' structures and conservation states, aiding in optimal exhibition conditions.
- - Neutron-based techniques, recognized for being non-invasive and non-destructive, are utilized globally to analyze historical and cultural artefacts, revealing crucial details about their composition, manufacturing methods, and alterations due to environmental factors.
- - The text reviews key neutron methods for characterizing materials in Cultural Heritage, discusses the sensors and detectors used, and presents case studies demonstrating their significant impact in various archaeological and historical settings.
Aggregation states of amyloid beta peptides for amyloid beta A β 1 - 40 to A β 1 - 42 and A β p 3 - 42 are investigated through small angle neutron scattering (SANS). The knowledge of these small peptides and their aggregation state are of key importance for the comprehension of neurodegenerative diseases (e.g.
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- Neutron scattering, scanning electron, and atomic force microscopy were used to analyze the elemental and structural properties of two types of stainless steel orthodontic archwires, confirming they are both austenitic stainless steel type AISI 304.
- The neutron technique's enhanced sensitivity allowed for precise measurement of composition factors and pitting resistance, revealing a significant martensite phase in the G&H wire due to its lower stability and processing issues.
- These findings provide insights into how alloy composition and material processing affect corrosion resistance and mechanical properties, suggesting this methodology could apply to the study of other biomedical materials in the future.
Article Synopsis
- The study presents a refined detection method for yttrium-aluminum-perovskite detectors on the VESUVIO spectrometer, resulting in a significant increase in photon count rates—up to three times higher.
- This optimization leads to a notable reduction in both the relative error bars (by about 40%) and noise levels (by around 35%) during deep inelastic neutron scattering measurements.
- The improvements also enhance the accuracy of line shape analysis in neutron Compton profiles and support better detection of anisotropy and anharmonicity in local potentials, potentially benefiting future research at VESUVIO.
Article Synopsis
- - The study focused on the grave goods of Kha and Merit from ancient Egypt, housed at the Museo Egizio in Turin, using advanced techniques like neutron imaging and gamma analysis.
- - This non-destructive research revealed detailed structural information about the inner contents of alabaster and metallic vases found in the tombs.
- - Findings included insights into the vases' isotopic and phase composition, enhancing our understanding of their contents and potential purposes in ancient practices.
Article Synopsis
- Researchers analyzed two brands of orthodontic archwires, G&H and Azdent, using neutron diffraction to study their metallurgical and phase structure.
- The findings revealed a bi-phase structure in the archwires, with G&H containing 45.67% martensitic phase and Azdent 6.62%, suggesting changes during the wire's cold working fabrication process.
- Additional analyses provided insight into atomic and isotopic compositions, linking the alloying elements to the mechanical properties, such as strength and ductility, of the materials used.
Article Synopsis
- The study introduces the first direct measurements of nuclear momentum distribution anisotropy and quantum kinetic energy in water at its triple point, utilizing deep inelastic neutron scattering (DINS).
- It analyzes hydrogen momentum distributions through an anisotropic Gaussian model, yielding precise kinetic energy data for both stable and metastable (supercooled) water.
- The findings enhance the understanding of hydrogen's quantum state in various water phases and improve the applicability of DINS for researching nuclear quantum effects, providing valuable reference data for future theoretical studies.
Article Synopsis
- The research investigated how water and ice behave at the particle level when adsorbed in graphene oxide sponges at two temperatures: 293 K and 20 K.
- Using Deep Inelastic Neutron Scattering (DINS), scientists measured the kinetic energy and momentum distribution of hydrogen in these materials to understand hydrogen's dynamics in a two-dimensional confined space.
- Results showed that hydrogen in water and ice exhibited unique behavior, with energy levels higher than those in bulk materials, highlighting the interplay between the adsorbed water/ice and the structure of the GO sponge.
Article Synopsis
- - The study used Inelastic Neutron Scattering to measure the OH stretching vibrational spectrum of water between 269 K and 296 K, revealing that the mean kinetic energy of protons remains nearly constant with temperature, indicating weak quantum effects on hydrogen bonds.
- - For ice, advanced calculations matched experimental results, showing that the ratio of stretching kinetic energy to total kinetic energy increases from ice to liquid to vapor, highlighting stronger hydrogen bonding in ice compared to liquid and vapor phases.
- - Interestingly, the research discovered that in the metastable liquid phase, this ratio hits a minimum, suggesting that intermolecular interactions in supercooled water are actually stronger than previously thought, challenging established beliefs about hydrogen bonding in supercooled water.
Article Synopsis
- - The study utilized Deep Inelastic Neutron Scattering (DINS) to analyze water confined in mesoporous silica at room temperature, focusing on the interactions between water protons and silanol groups on the surface.
- - Researchers controlled water adsorption to achieve a 1:1 ratio of water molecules to silanol groups, allowing for a precise measurement of the system's proton dynamics and organization.
- - The findings indicate that the hydrogen bonds formed between water protons and the silanol oxygen are significantly stronger than those found in bulk water, suggesting unique structural properties in confined water environments.