The Experts below are selected from a list of 4230 Experts worldwide ranked by ideXlab platform

D M Dobrev - One of the best experts on this subject based on the ideXlab platform.

  • improvement of the catv Coaxial Distribution system parameters
    2012
    Co-Authors: L T Jordanova, D M Dobrev
    Abstract:

    Summary The paper deals with Coaxial part of HFC CATV system. System parameters determinative in obtaining the desired signal level, carrier-to-noise ratio and acceptable nonlinear distortions are considered. Formulae for the gain and the maximum number of RF amplifiers in the longest Coaxial link are developed. A mathematical model of the return path channel is suggested with the noise-funneling effect being taken into consideration. Experimental and analytical results are shown that enable the engineer to determine the optimum operating level for a return path laser. A special attention is drawn to the design of the subscribers’ Distribution network and to the equalization of the downstream and upstream signal levels in particular. Two methods to set and maintain the balance of the return path are described that make it possible for some of the signal characteristics to be monitored.

T R Hsing - One of the best experts on this subject based on the ideXlab platform.

  • architectural alternatives of wireless access through hybrid fiber coax Distribution plant
    Global Communications Conference, 1995
    Co-Authors: W Y Chen, T R Hsing
    Abstract:

    Due to the smaller microcell size, a limited distance transmission on the Coaxial Distribution plant is still required when using the hybrid fiber/Coaxial (HFC) Distribution plant to provide wireless access. It is found that the transmission capability of the Coaxial Distribution plant is generally better than that of the air interface. However, the available spectrum, especially in the upstream direction, is limited. Three architectural alternatives are identified. The first one uses the Coaxial cables between the fiber node (FN) and first line amplifiers to provide radio frequency (RF) transmission with or without carrier frequency conversion. The second establishes fixed transmission links between the FN and radio ports using a simple digital modulation method such as QPSK. The third requires efficient transmission schemes and advanced media access protocols to establish a local area network (LAN) to provide flexible high rate wireless access services.

L T Jordanova - One of the best experts on this subject based on the ideXlab platform.

  • improvement of the catv Coaxial Distribution system parameters
    2012
    Co-Authors: L T Jordanova, D M Dobrev
    Abstract:

    Summary The paper deals with Coaxial part of HFC CATV system. System parameters determinative in obtaining the desired signal level, carrier-to-noise ratio and acceptable nonlinear distortions are considered. Formulae for the gain and the maximum number of RF amplifiers in the longest Coaxial link are developed. A mathematical model of the return path channel is suggested with the noise-funneling effect being taken into consideration. Experimental and analytical results are shown that enable the engineer to determine the optimum operating level for a return path laser. A special attention is drawn to the design of the subscribers’ Distribution network and to the equalization of the downstream and upstream signal levels in particular. Two methods to set and maintain the balance of the return path are described that make it possible for some of the signal characteristics to be monitored.

W Y Chen - One of the best experts on this subject based on the ideXlab platform.

  • architectural alternatives of wireless access through hybrid fiber coax Distribution plant
    Global Communications Conference, 1995
    Co-Authors: W Y Chen, T R Hsing
    Abstract:

    Due to the smaller microcell size, a limited distance transmission on the Coaxial Distribution plant is still required when using the hybrid fiber/Coaxial (HFC) Distribution plant to provide wireless access. It is found that the transmission capability of the Coaxial Distribution plant is generally better than that of the air interface. However, the available spectrum, especially in the upstream direction, is limited. Three architectural alternatives are identified. The first one uses the Coaxial cables between the fiber node (FN) and first line amplifiers to provide radio frequency (RF) transmission with or without carrier frequency conversion. The second establishes fixed transmission links between the FN and radio ports using a simple digital modulation method such as QPSK. The third requires efficient transmission schemes and advanced media access protocols to establish a local area network (LAN) to provide flexible high rate wireless access services.

Saad A Khan - One of the best experts on this subject based on the ideXlab platform.

  • effect of ph on protein Distribution in electrospun pva bsa composite nanofibers
    Biomacromolecules, 2012
    Co-Authors: Christina Tang, Evren A Ozcam, Brendon Stout, Saad A Khan
    Abstract:

    We examine the protein Distribution within an electrospun polymer nanofiber using polyvinyl alcohol and bovine serum albumin as a model system. We hypothesize that the location of the protein within the nanofiber can be controlled by carefully selecting the pH and the applied polarity of the electric field as the pH affects the net charge on the proteins. Using fluorescently labeled BSA and surface analysis, we observe that the Distribution of BSA is affected by the pH of the electrospinning solution. Therefore, we further probe the relevant forces on the protein in solution during electrospinning. The role of hydrodynamic friction was assessed using glutaraldehyde and HCl as a tool to modify the viscosity of the solution during electrospinning. By varying the pH and the polarity of the applied electric field, we evaluated the effects of electrostatic forces and dielectrophoresis on the protein during fiber formation. We surmise that electrostatic forces and hydrodynamic friction are insignificant relative to dielectrophoretic forces; therefore, it is possible to separate species in a blend using polarizability contrast. A Coaxial Distribution of protein in the core can be obtained by electrospinning at the isoelectric point of the protein, whereas surface enrichment can be obtained when the protein carries a net charge.