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Marco Geppi - One of the best experts on this subject based on the ideXlab platform.
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dynamics of dimethylbutanols in plastic crystalline phases by field cycling 1h nmr relaxometry
Journal of Physical Chemistry B, 2018Co-Authors: Elisa Carignani, Ewa Juszynskagalązka, Miroslaw Galązka, Maria Massalskaarodź, Claudia Forte, Marco Geppi, Alessandro Mandoli, Lucia CalucciAbstract:2,2-Dimethylbutan-1-ol (2,2-DM-1-B), 3,3-dimethylbutan-1-ol (3,3-DM-1-B), and 3,3-dimethylbutan-2-ol (3,3-DM-2-B) show a rich solid-state polymorphism, which includes one or more plastic crystalline phases (also referred to as orientationally disordered crystalline (ODIC) phases) and glass of the liquid or ODIC phases. In this work, the dynamics of the three isomeric alcohols was investigated in the liquid and plastic crystalline phases by fast field cycling 1H NMR relaxometry in the temperature range between 213 and 303 K. The analysis of the nuclear magnetic relaxation dispersion curves (i.e., longitudinal relaxation rate R1 vs 1H Larmor Frequency) acquired for the different alcohols at different temperatures gave quantitative information on internal motions, overall molecular reorientations, and molecular self-diffusion. Self-diffusion coefficients were also determined in the liquid phase and in some ODIC phases of the samples from the trends of 1H R1 as a function of the Frequency square root at low f...
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dynamics of the chiral liquid crystal 4 butyl 4 s 2 methylbutoxy azoxybenzene in the isotropic cholesteric and solid phases a fast field cycling nmr relaxometry study
Journal of Physical Chemistry B, 2016Co-Authors: Elisa Carignani, Lucia Calucci, Ewa Juszynskagalązka, Miroslaw Galązka, Maria Massalskaarodź, Claudia Forte, Marco GeppiAbstract:1H NMR relaxometry was applied to investigate dynamic processes in the isotropic liquid, cholesteric, and crystalline phases of the chiral mesogen 4′-butyl-4-(S)-(2-methylbutoxy)azoxybenzene (4ABO5*). To this aim, 1H longitudinal relaxation rates were measured as a function of temperature (between 257 and 319 K) and Larmor Frequency (from 10 kHz to 35 MHz by a fast field-cycling relaxometer and at 400 MHz by an NMR spectrometer). The NMR relaxation dispersion (NMRD) curves so obtained were analyzed in terms of models suitable for the description of dynamic processes in the different phases, thus quantitatively determining values of characteristic motional parameters. In particular, internal and overall rotations/reorientations, molecular translational diffusion, and collective motions contribute to relaxation in the isotropic and cholesteric phases, whereas, in the crystalline phase, relaxation is mainly determined by internal motions and molecular reorientations. The results were discussed and compared w...
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Dynamics of the Chiral Liquid Crystal 4′-Butyl-4‑(S)‑(2-methylbutoxy)azoxybenzene in the Isotropic, Cholesteric, and Solid Phases: A Fast Field-Cycling NMR Relaxometry Study
2016Co-Authors: Elisa Carignani, Lucia Calucci, Claudia Forte, Ewa Juszyńska-gałązka, Mirosław Gałązka, Maria Massalska-arodź, Marco GeppiAbstract:1H NMR relaxometry was applied to investigate dynamic processes in the isotropic liquid, cholesteric, and crystalline phases of the chiral mesogen 4′-butyl-4-(S)-(2-methylbutoxy)azoxybenzene (4ABO5*). To this aim, 1H longitudinal relaxation rates were measured as a function of temperature (between 257 and 319 K) and Larmor Frequency (from 10 kHz to 35 MHz by a fast field-cycling relaxometer and at 400 MHz by an NMR spectrometer). The NMR relaxation dispersion (NMRD) curves so obtained were analyzed in terms of models suitable for the description of dynamic processes in the different phases, thus quantitatively determining values of characteristic motional parameters. In particular, internal and overall rotations/reorientations, molecular translational diffusion, and collective motions contribute to relaxation in the isotropic and cholesteric phases, whereas, in the crystalline phase, relaxation is mainly determined by internal motions and molecular reorientations. The results were discussed and compared with those previously obtained on the same compound by dielectric relaxation spectroscopy
Elisa Carignani - One of the best experts on this subject based on the ideXlab platform.
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dynamics of dimethylbutanols in plastic crystalline phases by field cycling 1h nmr relaxometry
Journal of Physical Chemistry B, 2018Co-Authors: Elisa Carignani, Ewa Juszynskagalązka, Miroslaw Galązka, Maria Massalskaarodź, Claudia Forte, Marco Geppi, Alessandro Mandoli, Lucia CalucciAbstract:2,2-Dimethylbutan-1-ol (2,2-DM-1-B), 3,3-dimethylbutan-1-ol (3,3-DM-1-B), and 3,3-dimethylbutan-2-ol (3,3-DM-2-B) show a rich solid-state polymorphism, which includes one or more plastic crystalline phases (also referred to as orientationally disordered crystalline (ODIC) phases) and glass of the liquid or ODIC phases. In this work, the dynamics of the three isomeric alcohols was investigated in the liquid and plastic crystalline phases by fast field cycling 1H NMR relaxometry in the temperature range between 213 and 303 K. The analysis of the nuclear magnetic relaxation dispersion curves (i.e., longitudinal relaxation rate R1 vs 1H Larmor Frequency) acquired for the different alcohols at different temperatures gave quantitative information on internal motions, overall molecular reorientations, and molecular self-diffusion. Self-diffusion coefficients were also determined in the liquid phase and in some ODIC phases of the samples from the trends of 1H R1 as a function of the Frequency square root at low f...
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dynamics of the chiral liquid crystal 4 butyl 4 s 2 methylbutoxy azoxybenzene in the isotropic cholesteric and solid phases a fast field cycling nmr relaxometry study
Journal of Physical Chemistry B, 2016Co-Authors: Elisa Carignani, Lucia Calucci, Ewa Juszynskagalązka, Miroslaw Galązka, Maria Massalskaarodź, Claudia Forte, Marco GeppiAbstract:1H NMR relaxometry was applied to investigate dynamic processes in the isotropic liquid, cholesteric, and crystalline phases of the chiral mesogen 4′-butyl-4-(S)-(2-methylbutoxy)azoxybenzene (4ABO5*). To this aim, 1H longitudinal relaxation rates were measured as a function of temperature (between 257 and 319 K) and Larmor Frequency (from 10 kHz to 35 MHz by a fast field-cycling relaxometer and at 400 MHz by an NMR spectrometer). The NMR relaxation dispersion (NMRD) curves so obtained were analyzed in terms of models suitable for the description of dynamic processes in the different phases, thus quantitatively determining values of characteristic motional parameters. In particular, internal and overall rotations/reorientations, molecular translational diffusion, and collective motions contribute to relaxation in the isotropic and cholesteric phases, whereas, in the crystalline phase, relaxation is mainly determined by internal motions and molecular reorientations. The results were discussed and compared w...
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Dynamics of the Chiral Liquid Crystal 4′-Butyl-4‑(S)‑(2-methylbutoxy)azoxybenzene in the Isotropic, Cholesteric, and Solid Phases: A Fast Field-Cycling NMR Relaxometry Study
2016Co-Authors: Elisa Carignani, Lucia Calucci, Claudia Forte, Ewa Juszyńska-gałązka, Mirosław Gałązka, Maria Massalska-arodź, Marco GeppiAbstract:1H NMR relaxometry was applied to investigate dynamic processes in the isotropic liquid, cholesteric, and crystalline phases of the chiral mesogen 4′-butyl-4-(S)-(2-methylbutoxy)azoxybenzene (4ABO5*). To this aim, 1H longitudinal relaxation rates were measured as a function of temperature (between 257 and 319 K) and Larmor Frequency (from 10 kHz to 35 MHz by a fast field-cycling relaxometer and at 400 MHz by an NMR spectrometer). The NMR relaxation dispersion (NMRD) curves so obtained were analyzed in terms of models suitable for the description of dynamic processes in the different phases, thus quantitatively determining values of characteristic motional parameters. In particular, internal and overall rotations/reorientations, molecular translational diffusion, and collective motions contribute to relaxation in the isotropic and cholesteric phases, whereas, in the crystalline phase, relaxation is mainly determined by internal motions and molecular reorientations. The results were discussed and compared with those previously obtained on the same compound by dielectric relaxation spectroscopy
Lucia Calucci - One of the best experts on this subject based on the ideXlab platform.
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dynamics of dimethylbutanols in plastic crystalline phases by field cycling 1h nmr relaxometry
Journal of Physical Chemistry B, 2018Co-Authors: Elisa Carignani, Ewa Juszynskagalązka, Miroslaw Galązka, Maria Massalskaarodź, Claudia Forte, Marco Geppi, Alessandro Mandoli, Lucia CalucciAbstract:2,2-Dimethylbutan-1-ol (2,2-DM-1-B), 3,3-dimethylbutan-1-ol (3,3-DM-1-B), and 3,3-dimethylbutan-2-ol (3,3-DM-2-B) show a rich solid-state polymorphism, which includes one or more plastic crystalline phases (also referred to as orientationally disordered crystalline (ODIC) phases) and glass of the liquid or ODIC phases. In this work, the dynamics of the three isomeric alcohols was investigated in the liquid and plastic crystalline phases by fast field cycling 1H NMR relaxometry in the temperature range between 213 and 303 K. The analysis of the nuclear magnetic relaxation dispersion curves (i.e., longitudinal relaxation rate R1 vs 1H Larmor Frequency) acquired for the different alcohols at different temperatures gave quantitative information on internal motions, overall molecular reorientations, and molecular self-diffusion. Self-diffusion coefficients were also determined in the liquid phase and in some ODIC phases of the samples from the trends of 1H R1 as a function of the Frequency square root at low f...
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dynamics of the chiral liquid crystal 4 butyl 4 s 2 methylbutoxy azoxybenzene in the isotropic cholesteric and solid phases a fast field cycling nmr relaxometry study
Journal of Physical Chemistry B, 2016Co-Authors: Elisa Carignani, Lucia Calucci, Ewa Juszynskagalązka, Miroslaw Galązka, Maria Massalskaarodź, Claudia Forte, Marco GeppiAbstract:1H NMR relaxometry was applied to investigate dynamic processes in the isotropic liquid, cholesteric, and crystalline phases of the chiral mesogen 4′-butyl-4-(S)-(2-methylbutoxy)azoxybenzene (4ABO5*). To this aim, 1H longitudinal relaxation rates were measured as a function of temperature (between 257 and 319 K) and Larmor Frequency (from 10 kHz to 35 MHz by a fast field-cycling relaxometer and at 400 MHz by an NMR spectrometer). The NMR relaxation dispersion (NMRD) curves so obtained were analyzed in terms of models suitable for the description of dynamic processes in the different phases, thus quantitatively determining values of characteristic motional parameters. In particular, internal and overall rotations/reorientations, molecular translational diffusion, and collective motions contribute to relaxation in the isotropic and cholesteric phases, whereas, in the crystalline phase, relaxation is mainly determined by internal motions and molecular reorientations. The results were discussed and compared w...
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Dynamics of the Chiral Liquid Crystal 4′-Butyl-4‑(S)‑(2-methylbutoxy)azoxybenzene in the Isotropic, Cholesteric, and Solid Phases: A Fast Field-Cycling NMR Relaxometry Study
2016Co-Authors: Elisa Carignani, Lucia Calucci, Claudia Forte, Ewa Juszyńska-gałązka, Mirosław Gałązka, Maria Massalska-arodź, Marco GeppiAbstract:1H NMR relaxometry was applied to investigate dynamic processes in the isotropic liquid, cholesteric, and crystalline phases of the chiral mesogen 4′-butyl-4-(S)-(2-methylbutoxy)azoxybenzene (4ABO5*). To this aim, 1H longitudinal relaxation rates were measured as a function of temperature (between 257 and 319 K) and Larmor Frequency (from 10 kHz to 35 MHz by a fast field-cycling relaxometer and at 400 MHz by an NMR spectrometer). The NMR relaxation dispersion (NMRD) curves so obtained were analyzed in terms of models suitable for the description of dynamic processes in the different phases, thus quantitatively determining values of characteristic motional parameters. In particular, internal and overall rotations/reorientations, molecular translational diffusion, and collective motions contribute to relaxation in the isotropic and cholesteric phases, whereas, in the crystalline phase, relaxation is mainly determined by internal motions and molecular reorientations. The results were discussed and compared with those previously obtained on the same compound by dielectric relaxation spectroscopy
Z Chowdhuri - One of the best experts on this subject based on the ideXlab platform.
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magnetic field uniformity in neutron electric dipole moment experiments
Physical Review A, 2019Co-Authors: C Abel, N J Ayres, T Baker, G Bison, K Bodek, V Bondar, C Crawford, P J Chiu, E Chanel, Z ChowdhuriAbstract:Magnetic field uniformity is of the utmost importance in experiments to measure the electric dipole moment of the neutron. A general parametrization of the magnetic field in terms of harmonic polynomial modes is proposed, going beyond the linear-gradients approximation. We review the main undesirable effects of non-uniformities: depolarization of ultracold neutrons, and Larmor Frequency shifts of neutrons and mercury atoms. The theoretical predictions for these effects were verified by dedicated measurements with the single-chamber nEDM apparatus installed at the Paul Scherrer Institute.
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measurement of a false electric dipole moment signal from 199hg atoms exposed to an inhomogeneous magnetic field
European Physical Journal D, 2015Co-Authors: G Bison, K Bodek, Z Chowdhuri, S Afach, C A Baker, M Daum, M Fertl, B FrankeAbstract:We report on the measurement of a Larmor Frequency shift proportional to the electric-field strength for 199Hg atoms contained in a volume permeated with aligned magnetic and electric fields. This shift arises from the interplay between the inevitable magnetic field gradients and the motional magnetic field. The proportionality to electric-field strength makes it apparently similar to an electric dipole moment (EDM) signal, although unlike an EDM this effect is P- and T-conserving. We have used a neutron magnetic resonance EDM spectrometer, featuring a mercury co-magnetometer and an array of external cesium magnetometers, to measure the shift as a function of the applied magnetic field gradient. Our results are in good agreement with theoretical expectations.
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measurement of a false electric dipole moment signal from 199 hg atoms exposed to an inhomogeneous magnetic field
arXiv: Atomic Physics, 2015Co-Authors: S Afach, G Bison, K Bodek, Z Chowdhuri, C A Baker, M Daum, M Fertl, B Franke, P Geltenbort, K GreenAbstract:We report on the measurement of a Larmor Frequency shift proportional to the electric-field strength for $^{199}{\rm Hg}$ atoms contained in a volume permeated with aligned magnetic and electric fields. This shift arises from the interplay between the inevitable magnetic field gradients and the motional magnetic field. The proportionality to electric-field strength makes it apparently similar to an electric dipole moment (EDM) signal, although unlike an EDM this effect is P- and T-conserving. We have used a neutron magnetic resonance EDM spectrometer, featuring a mercury co-magnetometer and an array of external cesium magnetometers, to measure the shift as a function of the applied magnetic field gradient. Our results are in good agreement with theoretical expectations.
Claudia Forte - One of the best experts on this subject based on the ideXlab platform.
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dynamics of dimethylbutanols in plastic crystalline phases by field cycling 1h nmr relaxometry
Journal of Physical Chemistry B, 2018Co-Authors: Elisa Carignani, Ewa Juszynskagalązka, Miroslaw Galązka, Maria Massalskaarodź, Claudia Forte, Marco Geppi, Alessandro Mandoli, Lucia CalucciAbstract:2,2-Dimethylbutan-1-ol (2,2-DM-1-B), 3,3-dimethylbutan-1-ol (3,3-DM-1-B), and 3,3-dimethylbutan-2-ol (3,3-DM-2-B) show a rich solid-state polymorphism, which includes one or more plastic crystalline phases (also referred to as orientationally disordered crystalline (ODIC) phases) and glass of the liquid or ODIC phases. In this work, the dynamics of the three isomeric alcohols was investigated in the liquid and plastic crystalline phases by fast field cycling 1H NMR relaxometry in the temperature range between 213 and 303 K. The analysis of the nuclear magnetic relaxation dispersion curves (i.e., longitudinal relaxation rate R1 vs 1H Larmor Frequency) acquired for the different alcohols at different temperatures gave quantitative information on internal motions, overall molecular reorientations, and molecular self-diffusion. Self-diffusion coefficients were also determined in the liquid phase and in some ODIC phases of the samples from the trends of 1H R1 as a function of the Frequency square root at low f...
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dynamics of the chiral liquid crystal 4 butyl 4 s 2 methylbutoxy azoxybenzene in the isotropic cholesteric and solid phases a fast field cycling nmr relaxometry study
Journal of Physical Chemistry B, 2016Co-Authors: Elisa Carignani, Lucia Calucci, Ewa Juszynskagalązka, Miroslaw Galązka, Maria Massalskaarodź, Claudia Forte, Marco GeppiAbstract:1H NMR relaxometry was applied to investigate dynamic processes in the isotropic liquid, cholesteric, and crystalline phases of the chiral mesogen 4′-butyl-4-(S)-(2-methylbutoxy)azoxybenzene (4ABO5*). To this aim, 1H longitudinal relaxation rates were measured as a function of temperature (between 257 and 319 K) and Larmor Frequency (from 10 kHz to 35 MHz by a fast field-cycling relaxometer and at 400 MHz by an NMR spectrometer). The NMR relaxation dispersion (NMRD) curves so obtained were analyzed in terms of models suitable for the description of dynamic processes in the different phases, thus quantitatively determining values of characteristic motional parameters. In particular, internal and overall rotations/reorientations, molecular translational diffusion, and collective motions contribute to relaxation in the isotropic and cholesteric phases, whereas, in the crystalline phase, relaxation is mainly determined by internal motions and molecular reorientations. The results were discussed and compared w...
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Dynamics of the Chiral Liquid Crystal 4′-Butyl-4‑(S)‑(2-methylbutoxy)azoxybenzene in the Isotropic, Cholesteric, and Solid Phases: A Fast Field-Cycling NMR Relaxometry Study
2016Co-Authors: Elisa Carignani, Lucia Calucci, Claudia Forte, Ewa Juszyńska-gałązka, Mirosław Gałązka, Maria Massalska-arodź, Marco GeppiAbstract:1H NMR relaxometry was applied to investigate dynamic processes in the isotropic liquid, cholesteric, and crystalline phases of the chiral mesogen 4′-butyl-4-(S)-(2-methylbutoxy)azoxybenzene (4ABO5*). To this aim, 1H longitudinal relaxation rates were measured as a function of temperature (between 257 and 319 K) and Larmor Frequency (from 10 kHz to 35 MHz by a fast field-cycling relaxometer and at 400 MHz by an NMR spectrometer). The NMR relaxation dispersion (NMRD) curves so obtained were analyzed in terms of models suitable for the description of dynamic processes in the different phases, thus quantitatively determining values of characteristic motional parameters. In particular, internal and overall rotations/reorientations, molecular translational diffusion, and collective motions contribute to relaxation in the isotropic and cholesteric phases, whereas, in the crystalline phase, relaxation is mainly determined by internal motions and molecular reorientations. The results were discussed and compared with those previously obtained on the same compound by dielectric relaxation spectroscopy
