The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform

Afshin S. Daryoush - One of the best experts on this subject based on the ideXlab platform.

  • Improvement of both bandwidth and driving voltage of Polymer Phase modulators using buried in-plane coupled micro-strip driving electrodes
    Journal of Applied Physics, 2017
    Co-Authors: Massinissa Hadjloum, Mohammed El Gibari, Afshin S. Daryoush
    Abstract:

    A large performance improvement of Polymer Phase modulators is reported by using buried in-plane coupled microstrip (CMS) driving electrodes, instead of standard vertical Micro-Strip electrodes. The in-plane CMS driving electrodes have both low radio frequency (RF) losses and high overlap integral between optical and RF waves compared to the vertical designs. Since the optical waveguide and CMS electrodes are located in the same plane, optical injection and microwave driving access cannot be separated perpendicularly without intersection between them. A via-less transition between grounded coplanar waveguide access and CMS driving electrodes is introduced in order to provide broadband excitation of optical Phase modulators and avoid the intersection of the optical core and the electrical probe. Simulation and measurement results of the benzocyclobutene Polymer as a cladding material and the PMMI-CPO1 Polymer as an optical core with an electro-optic coefficient of 70pm/V demonstrate a broadband operation of 67GHz using travelling-wave driving electrodes with a half-wave voltage of 4.5 V, while satisfying its low RF losses and high overlap integral between optical and RF waves of in-plane CMS electrodes

Massinissa Hadjloum - One of the best experts on this subject based on the ideXlab platform.

  • Improvement of both bandwidth and driving voltage of Polymer Phase modulators using buried in-plane coupled micro-strip driving electrodes
    Journal of Applied Physics, 2017
    Co-Authors: Massinissa Hadjloum, Mohammed El Gibari, Afshin S. Daryoush
    Abstract:

    A large performance improvement of Polymer Phase modulators is reported by using buried in-plane coupled microstrip (CMS) driving electrodes, instead of standard vertical Micro-Strip electrodes. The in-plane CMS driving electrodes have both low radio frequency (RF) losses and high overlap integral between optical and RF waves compared to the vertical designs. Since the optical waveguide and CMS electrodes are located in the same plane, optical injection and microwave driving access cannot be separated perpendicularly without intersection between them. A via-less transition between grounded coplanar waveguide access and CMS driving electrodes is introduced in order to provide broadband excitation of optical Phase modulators and avoid the intersection of the optical core and the electrical probe. Simulation and measurement results of the benzocyclobutene Polymer as a cladding material and the PMMI-CPO1 Polymer as an optical core with an electro-optic coefficient of 70pm/V demonstrate a broadband operation of 67GHz using travelling-wave driving electrodes with a half-wave voltage of 4.5 V, while satisfying its low RF losses and high overlap integral between optical and RF waves of in-plane CMS electrodes

Yoichiro Ito - One of the best experts on this subject based on the ideXlab platform.

  • countercurrent chromatographic separation and purification of various ribonucleases using a small scale cross axis coil planet centrifuge with aqueous aqueous Polymer Phase systems
    Journal of Chromatography B, 2009
    Co-Authors: Kazufusa Shinomiya, Hiroko Kobayashi, Naomi Motoyoshi, Norio Inokuchi, Kazuya Nakagomi, Yoichiro Ito
    Abstract:

    Countercurrent chromatographic (CCC) separation and purification of various ribonucleases (RNases) was performed using the small-scale cross-axis coil planet centrifuge (X-axis CPC) with aqueous-aqueous Polymer Phase systems. RNases B and A were well resolved from each other with an aqueous-aqueous Polymer Phase system composed of 12.5% (w/w) polyethylene glycol (PEG) 1000 and 12.5% (w/w) dibasic potassium phosphate (pH 9.2) as the mobile lower Phase. The commercial RNase A samples obtained from three different companies were also highly purified using the 16.0% (w/w) PEG 1000-6.3% (w/w) dibasic potassium phosphate-6.3% (w/w) monobasic potassium phosphate system (pH 6.6) using the upper Phase as the mobile Phase. Recombinant RNase Po(1), an RNase T(1) family enzyme, was further successfully separated from the crude extract using the same solvent system with the lower Phase used as the mobile Phase. The RNase activities were well preserved during the CCC separation. The overall results demonstrate that the small-scale X-axis CPC is useful for a simple and rapid purification of various RNases in a preparative-scale.

  • Protein separation by nonsynchronous coil planet centrifuge with aqueous-aqueous Polymer Phase systems.
    Journal of chromatography. A, 2003
    Co-Authors: Kazufusa Shinomiya, Yozo Kabasawa, Kazuhiro Yanagidaira, Haruo Sasaki, Minoru Muto, Tadashi Okada, Yoichiro Ito
    Abstract:

    Counter-current chromatographic separation of proteins was performed using a rotary-seal-free nonsynchronous coil planet centrifuge (CPC) fabricated in our laboratory. This apparatus has a unique feature that allows a freely adjustable rotational rate of the coiled separation column at a given revolution speed. The separation was performed using a set of stable proteins including cytochrome c, myoglobin and lysozyme with two different types of aqueous-aqueous Polymer Phase systems, i.e., PEG (polyethylene glycol) 1000-dibasic potassium phosphate, and PEG 8000-dextran T500 in 5 mM potassium phosphate buffer. Using a set of multilayer coiled columns prepared from 0.8 mm I.D. PTFE tubing with different volumes (11, 24, 39 ml), the effect of the column capacity on the partition efficiency was investigated under a given set of experimental conditions. Among these experiments, the best separation of proteins was attained using the 39 ml capacity column with a 12.5% (w/w) PEG 1000-12.5% (w/w) dibasic potassium phosphate system at 10 rpm of coil rotation under 800 rpm. With lower Phase mobile at 0.2 ml/min in the head-to-tail elution, the resolution between cytochrome c and myoglobin was 1.6 and that between myoglobin and lysozyme, 1.9. With upper Phase mobile in the head-to-tail elution, the resolution between lysozyme and myoglobin peaks was 1.5. In these two separations, the stationary Phase retention was 35.0 and 33.3%, respectively. Further studies were carried out using a pair of eccentric coil assemblies with 0.8 mm I.D. PTFE tubing at a total capacity of 20 ml. A comparable resolution was obtained using both lower and upper Phases as a mobile Phase in a head-to-tail elution. The results of our studies demonstrate that the nonsynchronous CPC is useful for protein separation with aqueous-aqueous Polymer Phase systems.

  • Protein separation by nonsynchronous coil planet centrifuge with aqueous–aqueous Polymer Phase systems
    Journal of Chromatography A, 2003
    Co-Authors: Kazufusa Shinomiya, Yozo Kabasawa, Kazuhiro Yanagidaira, Haruo Sasaki, Minoru Muto, Tadashi Okada, Yoichiro Ito
    Abstract:

    Counter-current chromatographic separation of proteins was performed using a rotary-seal-free nonsynchronous coil planet centrifuge (CPC) fabricated in our laboratory. This apparatus has a unique feature that allows a freely adjustable rotational rate of the coiled separation column at a given revolution speed. The separation was performed using a set of stable proteins including cytochrome c, myoglobin and lysozyme with two different types of aqueous-aqueous Polymer Phase systems, i.e., PEG (polyethylene glycol) 1000-dibasic potassium phosphate, and PEG 8000-dextran T500 in 5 mM potassium phosphate buffer. Using a set of multilayer coiled columns prepared from 0.8 mm I.D. PTFE tubing with different volumes (11, 24, 39 ml), the effect of the column capacity on the partition efficiency was investigated under a given set of experimental conditions. Among these experiments, the best separation of proteins was attained using the 39 ml capacity column with a 12.5% (w/w) PEG 1000-12.5% (w/w) dibasic potassium phosphate system at 10 rpm of coil rotation under 800 rpm. With lower Phase mobile at 0.2 ml/min in the head-to-tail elution, the resolution between cytochrome c and myoglobin was 1.6 and that between myoglobin and lysozyme, 1.9. With upper Phase mobile in the head-to-tail elution, the resolution between lysozyme and myoglobin peaks was 1.5. In these two separations, the stationary Phase retention was 35.0 and 33.3%, respectively. Further studies were carried out using a pair of eccentric coil assemblies with 0.8 mm I.D. PTFE tubing at a total capacity of 20 ml. A comparable resolution was obtained using both lower and upper Phases as a mobile Phase in a head-to-tail elution. The results of our studies demonstrate that the nonsynchronous CPC is useful for protein separation with aqueous-aqueous Polymer Phase systems.

  • Countercurrent Chromatographic Separation of Proteins by Cross-Axis Coil Planet Centrifuge: Choice of Polymer Phase Systems and Revolution Speed
    Journal of Liquid Chromatography & Related Technologies, 1998
    Co-Authors: Kazufusa Shinomiya, Yozo Kabasawa, Yoichiro Ito
    Abstract:

    Abstract Countercurrent chromatographic separation of proteins by the cross-axis coil planet centrifuge was maximized by selecting the suitable Polymer Phase system and revolution speed. Polymer Phase systems composed of polyethylene glycol (PEG) 1000 and several inorganic salts were examined to determine partition coefficient values (K) for various proteins. The overall results indicated that the Polymer Phase system composed of 12.5% (w/w) PEG 1000 and 12.5% (w/w) dibasic potassium phosphate yielded suitable K values for most proteins except for cytochrome C and apo-transferrin which may be separable with a solvent system composed of 12.5% (w/w) PEG 1000 and 24% (w/w) potassium citrate. A series of experiments with the PEG 1000 - potassium phosphate system under various revolution speeds revealed that the best separation was achieved at 850 rpm. The above optimized conditions may be applied to separations of other protein samples.

  • Counter-current chromatography of lipoproteins with a Polymer Phase system using the cross-axis synchronous coil planet centrifuge.
    Journal of chromatography, 1992
    Co-Authors: Yoichi Shibusawa, Yoichiro Ito, Katsunori Ikewaki, Daniel J. Rader, H. Bryan Brewer
    Abstract:

    Abstract Lipoproteins were separated by counter-current chromatography using the type-XLL coil planet centrifuge. The separation was performed with a Polymer Phase system composed of 16% (w/w) polyethylene glycol 1000 and 12.5% (w/w) dibasic potassium phosphate by eluting the lower Phase at a flow rate of 0.5 ml/min. About 5 ml of the sample solution containing approximately 150 mg of a lipoprotein mixture were loaded. High- and low-density lipoproteins were resolved within 12 h. Each component was detected by gel electrophoresis with oil red staining.

Erik Luijten - One of the best experts on this subject based on the ideXlab platform.

  • Critical Polymer-Polymer Phase separation in ternary solutions
    The Journal of chemical physics, 2005
    Co-Authors: Lei Guo, Erik Luijten
    Abstract:

    We study Polymer-Polymer Phase separation in a common good solvent by means of Monte Carlo simulations of the bond-fluctuation model. Below a critical, chain-length-dependent concentration, no Phase separation occurs. For higher concentrations, the critical demixing temperature scales nonlinearly with the total monomer concentration, with a power law relatively close to a renormalization-group prediction based on “blob” scaling arguments. We point out that earlier simulations and experiments have tested this power-law dependence at concentrations outside the validity regime of the scaling arguments. The critical amplitudes of the order parameter and the zero-angle scattering intensity also exhibit chain-length dependences that differ from the conventional predictions but are in excellent agreement with the renormalization-group results. In addition, we characterize the variation of the average coil shape upon Phase separation.

Mohammed El Gibari - One of the best experts on this subject based on the ideXlab platform.

  • Improvement of both bandwidth and driving voltage of Polymer Phase modulators using buried in-plane coupled micro-strip driving electrodes
    Journal of Applied Physics, 2017
    Co-Authors: Massinissa Hadjloum, Mohammed El Gibari, Afshin S. Daryoush
    Abstract:

    A large performance improvement of Polymer Phase modulators is reported by using buried in-plane coupled microstrip (CMS) driving electrodes, instead of standard vertical Micro-Strip electrodes. The in-plane CMS driving electrodes have both low radio frequency (RF) losses and high overlap integral between optical and RF waves compared to the vertical designs. Since the optical waveguide and CMS electrodes are located in the same plane, optical injection and microwave driving access cannot be separated perpendicularly without intersection between them. A via-less transition between grounded coplanar waveguide access and CMS driving electrodes is introduced in order to provide broadband excitation of optical Phase modulators and avoid the intersection of the optical core and the electrical probe. Simulation and measurement results of the benzocyclobutene Polymer as a cladding material and the PMMI-CPO1 Polymer as an optical core with an electro-optic coefficient of 70pm/V demonstrate a broadband operation of 67GHz using travelling-wave driving electrodes with a half-wave voltage of 4.5 V, while satisfying its low RF losses and high overlap integral between optical and RF waves of in-plane CMS electrodes