Paul Rochon - Profile on Academia.edu (original) (raw)
Papers by Paul Rochon
Generalized theory of magnetic field diffusion in superconducting cylinders: II
Journal of Low Temperature Physics, 1985
ABSTRACT
Cooperative Motion of Side Groups in Amorphous Polymers: Dipolar Interactions
Abstract : Two ester-type monomers with different polarity, BEM and NBEM, copolymerize with the a... more Abstract : Two ester-type monomers with different polarity, BEM and NBEM, copolymerize with the azo-containing monomer DR1M in random fashion and form amorphous copolymers. The polarity of BEM is comparable to the polarity of DR1M, and the electronic spectra confirm that BEM and DR1M interact with each other more strongly than NBEM and DR1M do. A nonlinear increase of the photoinduced birefringence as a function of azo content is found in DR1M copolymers with the polar BEM group, while the increase is linear in copolymers with the nonpolar NBEM group. Comparison between the two copolymer series suggests that the dipolar association between BEM and DR1M is the major factor causing cooperative motion in these amorphous copolymers enhancing the photoinduced birefringence. jg p.2
Linear and Nonlinear Optics of Organic Materials VIII, 2008
ABSTRACT Surface relief structures are optically inscribed onto azobenzene containing thin films.... more ABSTRACT Surface relief structures are optically inscribed onto azobenzene containing thin films. We present a brief review of the technique and results. The films act either as optical waveguides of as substrates upon which thin gold films are deposited to support surface plasmon waves. Multiple gratings are inscribed to act as optical couplers and Bragg gratings. Here, we report on the amplitude and phase changes that occur when the incident light is resonantly coupled into waveguide or surface plasmon modes. We illustrate the method of obtaining the dispersion curve of the device. The effects on amplitude are readily observed in the transmission or reflection spectra. In addition, since the structures can be made such that the resonant TE and TM modes to be well separated, we can measure the phase changes of the transmitted or reflected beams near resonance. A simple device showing polarization to wavelength modulation encoding is presented.
Journal of Pharmaceutical Sciences, 1990
High-field (300 MHz) 'H NMR spectral analysis and particle size distribution analysis employing t... more High-field (300 MHz) 'H NMR spectral analysis and particle size distribution analysis employing the quasielastic light scattering (QELS) technique were performed on samples of the 1st International Standard for low molecular weight (LMW) heparin derivatives recently selected by the World Health Organization (WHO). We propose that the results of these analyses, which showed that the material is highly homogeneous in particle size and retains spectral features characteristic of its porcine mucosal origin, form an appropriate basis for physicochemical comparison between the "Standard' and other LMW heparin preparations. Analogous to this information from the ' H data, the 13C
Effect of light polarization on the diffraction pattern of small wires
American Journal of Physics, 1985
American Journal of Physics, 2004
We reexamine the linear theory of wave propagation through an elastic string under uniform tensio... more We reexamine the linear theory of wave propagation through an elastic string under uniform tension or a slender elastic rod from a perspective that focuses on the flow of mechanical energy and mechanical momentum. Continuity equations are established for the flow of energy and momentum, leading to two boundary conditions for the net wave displacement. The important special case of a small amplitude pulse of arbitrary shape traveling through a uniform slender medium joined to another medium with a different linear mass density is examined in detail. The new boundary conditions lead to the correct relative amplitudes for the reflected and transmitted pulses. We obtain the instantaneous mechanical energy and momentum of the incident, reflected, and transmitted pulses and show that the net mechanical energy and momentum are separate constants of motion. The cases of an incoming pulse described by a Lorentzian and a Gaussian distribution are suggested as problems to be solved by the interested reader.
Forward Fraunhofer scattering from a semi-infinite plane
Journal of the Optical Society of America A, 1986
ABSTRACT
Photoconductivity and photovoltaic excitation spectra and their wavelength derivative in Cu2O
Journal of Physics and Chemistry of Solids, 1975
ABSTRACT
A simple method for the manufacture of mesoscopic metal wires
Journal of Materials Research, 1996
A process for the manufacture of very thin parallel wires has been developed. A series of paralle... more A process for the manufacture of very thin parallel wires has been developed. A series of parallel silver wires have been written for the study of one-dimensional electron transport. The wires are approximately 200 nm wide and 8 mm long. The method used can produce longer and thinner wires.
Erratum: ‘‘Diffraction of electrons and light by an obstacle: A comparative study’’ [Am. J. Phys. 53, 1005 (1985)]
American Journal of Physics, 1986
1998 International Conference on Applications of Photonic Technology III: Closing the Gap between Theory, Development, and Applications, 1998
Interaction of hepatic asialoglycoprotein receptor with dimyristoyl phosphatidylcholine vesicles
Biochemistry and Cell Biology, 1987
The hepatocyte membrane asialoglycoprotein receptor (ASGP-R) was extracted from rabbit liver, pur... more The hepatocyte membrane asialoglycoprotein receptor (ASGP-R) was extracted from rabbit liver, purified, and then incubated with preformed vesicles of dimyristoyl phosphatidylcholine. The association of protein with lipid was dependent on vesicle size and the best results were achieved with small vesicles of about 20 nm diameter. The ligand binding capacity of ASGP-R–vesicle complexes was also measured and found to be approximately sevenfold greater than free receptor in aqueous buffer and twofold greater than receptor solubilized in Triton X-100. Most likely, the reconstitution procedure used in these experiments does not result in transmembrane insertion of the receptor. ASGP-R probably resides on the surface of the vesicle, held there primarily by weak hydrophobic forces.
Hyperbolic identity for solving the cubic equation
American Journal of Physics, 1986
Photovoltaic Effect of a Au–Ge Barrier in a Quantizing Magnetic Field
Canadian Journal of Physics
A study is made of the oscillatory spectral distribution of the photovoltaic effect of a gold–ger... more A study is made of the oscillatory spectral distribution of the photovoltaic effect of a gold–germanium Schottky barrier in quantizing magnetic fields. The spectra are taken at 4.2 K in the Faraday configuration for fields of up to 70 kG. The results are analyzed in terms of the Pidgeon and Brown coupled bands theory of interband magneto-absorption. Excitonic effects are observed and discussed.
Diffraction from Small Wires, Including Surface Roughness
Optica Acta: International Journal of Optics
Maxwell&amp;#39;s theory has been successfully used to fit experimental data for the smal... more Maxwell&amp;#39;s theory has been successfully used to fit experimental data for the small-angle scattering of an optical beam by metallic wires with diameters of the order of 25 μm. An alteration of the theory to take into account surface roughness is proposed, and the results are used to fit the data obtained for a copper electroplated wire with surface irregularities.
Low-frequency voltage response of the direct current-induced intermediate state in a type I wire
Physica B+C
ABSTRACT
Photoinduced liquid crystal alignment based on a surface relief grating in an assembled cell
Applied Physics Letters, 1999
[Applied Physics Letters 74, 3791 (1999)]. Xiang Tong Li, Almeria Natansohn, Paul Rochon. Abstrac... more [Applied Physics Letters 74, 3791 (1999)]. Xiang Tong Li, Almeria Natansohn, Paul Rochon. Abstract. ... This theory which relates the azimuthal surface anchoring energy obtained from a grating to its spacing and depth has been experimentally tested by Kanel et al. ...
Macromolecules, 2002
Two copolymers, poly{4′-[[[2-(methacryloyloxy)ethyl]ethyl]amino]-4-nitroazobenzene}-co-[(methacry... more Two copolymers, poly{4′-[[[2-(methacryloyloxy)ethyl]ethyl]amino]-4-nitroazobenzene}-co-[(methacryloyloxy)-4-nitrophenyl-(S)-prolinol] (poly(DR1M-co-(S)-NPPMMA)) and poly{4-[2-methacryloyloxy)ethyl]azobenzene-co-[(methacryloyloxy)-4-nitrophenyl-(S)-prolinol] (poly(MEA-co-(S)-NPPMMA)), were synthesized and characterized. They contain side chain azobenzene chromophores (DR1 and MEA, respectively) and a prolinol-based chiral side chain group (NPP). Photoinduced birefringence, polarized absorption spectroscopy, and chiroptical properties (optical rotation and circular dichroism) in films were measured, and the results are discussed in relation to the structure of these copolymers. Cooperative motion of the chiral structural unit is observed for the photoinduced birefringence. Chirality is, however, not transmitted from the chiral structural unit to the azobenzene structural unit at the 1:1 compositions investigated here.
Generalized theory of magnetic field diffusion in superconducting cylinders: II
Journal of Low Temperature Physics, 1985
ABSTRACT
Cooperative Motion of Side Groups in Amorphous Polymers: Dipolar Interactions
Abstract : Two ester-type monomers with different polarity, BEM and NBEM, copolymerize with the a... more Abstract : Two ester-type monomers with different polarity, BEM and NBEM, copolymerize with the azo-containing monomer DR1M in random fashion and form amorphous copolymers. The polarity of BEM is comparable to the polarity of DR1M, and the electronic spectra confirm that BEM and DR1M interact with each other more strongly than NBEM and DR1M do. A nonlinear increase of the photoinduced birefringence as a function of azo content is found in DR1M copolymers with the polar BEM group, while the increase is linear in copolymers with the nonpolar NBEM group. Comparison between the two copolymer series suggests that the dipolar association between BEM and DR1M is the major factor causing cooperative motion in these amorphous copolymers enhancing the photoinduced birefringence. jg p.2
Linear and Nonlinear Optics of Organic Materials VIII, 2008
ABSTRACT Surface relief structures are optically inscribed onto azobenzene containing thin films.... more ABSTRACT Surface relief structures are optically inscribed onto azobenzene containing thin films. We present a brief review of the technique and results. The films act either as optical waveguides of as substrates upon which thin gold films are deposited to support surface plasmon waves. Multiple gratings are inscribed to act as optical couplers and Bragg gratings. Here, we report on the amplitude and phase changes that occur when the incident light is resonantly coupled into waveguide or surface plasmon modes. We illustrate the method of obtaining the dispersion curve of the device. The effects on amplitude are readily observed in the transmission or reflection spectra. In addition, since the structures can be made such that the resonant TE and TM modes to be well separated, we can measure the phase changes of the transmitted or reflected beams near resonance. A simple device showing polarization to wavelength modulation encoding is presented.
Journal of Pharmaceutical Sciences, 1990
High-field (300 MHz) 'H NMR spectral analysis and particle size distribution analysis employing t... more High-field (300 MHz) 'H NMR spectral analysis and particle size distribution analysis employing the quasielastic light scattering (QELS) technique were performed on samples of the 1st International Standard for low molecular weight (LMW) heparin derivatives recently selected by the World Health Organization (WHO). We propose that the results of these analyses, which showed that the material is highly homogeneous in particle size and retains spectral features characteristic of its porcine mucosal origin, form an appropriate basis for physicochemical comparison between the "Standard' and other LMW heparin preparations. Analogous to this information from the ' H data, the 13C
Effect of light polarization on the diffraction pattern of small wires
American Journal of Physics, 1985
American Journal of Physics, 2004
We reexamine the linear theory of wave propagation through an elastic string under uniform tensio... more We reexamine the linear theory of wave propagation through an elastic string under uniform tension or a slender elastic rod from a perspective that focuses on the flow of mechanical energy and mechanical momentum. Continuity equations are established for the flow of energy and momentum, leading to two boundary conditions for the net wave displacement. The important special case of a small amplitude pulse of arbitrary shape traveling through a uniform slender medium joined to another medium with a different linear mass density is examined in detail. The new boundary conditions lead to the correct relative amplitudes for the reflected and transmitted pulses. We obtain the instantaneous mechanical energy and momentum of the incident, reflected, and transmitted pulses and show that the net mechanical energy and momentum are separate constants of motion. The cases of an incoming pulse described by a Lorentzian and a Gaussian distribution are suggested as problems to be solved by the interested reader.
Forward Fraunhofer scattering from a semi-infinite plane
Journal of the Optical Society of America A, 1986
ABSTRACT
Photoconductivity and photovoltaic excitation spectra and their wavelength derivative in Cu2O
Journal of Physics and Chemistry of Solids, 1975
ABSTRACT
A simple method for the manufacture of mesoscopic metal wires
Journal of Materials Research, 1996
A process for the manufacture of very thin parallel wires has been developed. A series of paralle... more A process for the manufacture of very thin parallel wires has been developed. A series of parallel silver wires have been written for the study of one-dimensional electron transport. The wires are approximately 200 nm wide and 8 mm long. The method used can produce longer and thinner wires.
Erratum: ‘‘Diffraction of electrons and light by an obstacle: A comparative study’’ [Am. J. Phys. 53, 1005 (1985)]
American Journal of Physics, 1986
1998 International Conference on Applications of Photonic Technology III: Closing the Gap between Theory, Development, and Applications, 1998
Interaction of hepatic asialoglycoprotein receptor with dimyristoyl phosphatidylcholine vesicles
Biochemistry and Cell Biology, 1987
The hepatocyte membrane asialoglycoprotein receptor (ASGP-R) was extracted from rabbit liver, pur... more The hepatocyte membrane asialoglycoprotein receptor (ASGP-R) was extracted from rabbit liver, purified, and then incubated with preformed vesicles of dimyristoyl phosphatidylcholine. The association of protein with lipid was dependent on vesicle size and the best results were achieved with small vesicles of about 20 nm diameter. The ligand binding capacity of ASGP-R–vesicle complexes was also measured and found to be approximately sevenfold greater than free receptor in aqueous buffer and twofold greater than receptor solubilized in Triton X-100. Most likely, the reconstitution procedure used in these experiments does not result in transmembrane insertion of the receptor. ASGP-R probably resides on the surface of the vesicle, held there primarily by weak hydrophobic forces.
Hyperbolic identity for solving the cubic equation
American Journal of Physics, 1986
Photovoltaic Effect of a Au–Ge Barrier in a Quantizing Magnetic Field
Canadian Journal of Physics
A study is made of the oscillatory spectral distribution of the photovoltaic effect of a gold–ger... more A study is made of the oscillatory spectral distribution of the photovoltaic effect of a gold–germanium Schottky barrier in quantizing magnetic fields. The spectra are taken at 4.2 K in the Faraday configuration for fields of up to 70 kG. The results are analyzed in terms of the Pidgeon and Brown coupled bands theory of interband magneto-absorption. Excitonic effects are observed and discussed.
Diffraction from Small Wires, Including Surface Roughness
Optica Acta: International Journal of Optics
Maxwell&amp;#39;s theory has been successfully used to fit experimental data for the smal... more Maxwell&amp;#39;s theory has been successfully used to fit experimental data for the small-angle scattering of an optical beam by metallic wires with diameters of the order of 25 μm. An alteration of the theory to take into account surface roughness is proposed, and the results are used to fit the data obtained for a copper electroplated wire with surface irregularities.
Low-frequency voltage response of the direct current-induced intermediate state in a type I wire
Physica B+C
ABSTRACT
Photoinduced liquid crystal alignment based on a surface relief grating in an assembled cell
Applied Physics Letters, 1999
[Applied Physics Letters 74, 3791 (1999)]. Xiang Tong Li, Almeria Natansohn, Paul Rochon. Abstrac... more [Applied Physics Letters 74, 3791 (1999)]. Xiang Tong Li, Almeria Natansohn, Paul Rochon. Abstract. ... This theory which relates the azimuthal surface anchoring energy obtained from a grating to its spacing and depth has been experimentally tested by Kanel et al. ...
Macromolecules, 2002
Two copolymers, poly{4′-[[[2-(methacryloyloxy)ethyl]ethyl]amino]-4-nitroazobenzene}-co-[(methacry... more Two copolymers, poly{4′-[[[2-(methacryloyloxy)ethyl]ethyl]amino]-4-nitroazobenzene}-co-[(methacryloyloxy)-4-nitrophenyl-(S)-prolinol] (poly(DR1M-co-(S)-NPPMMA)) and poly{4-[2-methacryloyloxy)ethyl]azobenzene-co-[(methacryloyloxy)-4-nitrophenyl-(S)-prolinol] (poly(MEA-co-(S)-NPPMMA)), were synthesized and characterized. They contain side chain azobenzene chromophores (DR1 and MEA, respectively) and a prolinol-based chiral side chain group (NPP). Photoinduced birefringence, polarized absorption spectroscopy, and chiroptical properties (optical rotation and circular dichroism) in films were measured, and the results are discussed in relation to the structure of these copolymers. Cooperative motion of the chiral structural unit is observed for the photoinduced birefringence. Chirality is, however, not transmitted from the chiral structural unit to the azobenzene structural unit at the 1:1 compositions investigated here.