this study determines the impact of e-commerce (ec) on some of important economic criteria including total factor productivity( tfp) of iran country as a developing country in comparison with us standard as a developed country through analyzing and calculating interrelated issues. the model is based on both econometrics and growth accounting approach to fill the gaps of previous studies. on the...

in this paper, a photonic crystal waveguide with point defects and lattice constant perturbations of +5%, -5% are being investigated. firstly waveguide structures with constant and specific parameters are being studied and photonic band gap diagrams for te/tm modes are depicted; then pulse propagation in the frequencies available in the band gap are shown. after that, effects of parameters like...

The momentum conserving indirect excitonic transitions, from the ⌫ 15 valence band maximum to the conduction band minima close to the X 1 point in the Brillouin zone have been measured for GaP in piezo-modulated transmission. At 6 K, excitonic signatures due to phonon emission are observed at E gx ϩប␻ ph for TA͑X͒, LA͑X͒, and TO͑X͒ phonons ͑E gx ϭfree exciton band gap͒, whereas at 120 K signatures for ...

AB S TRACT We study the structure of a stationary and axisymmetric charge-deficient region (or a potential gap) in the outer magnetosphere of a spinning neutron star. A large electric field along the magnetic field lines is created in this potential gap and accelerates migratory electrons (e2) and/or positrons (e) to ultrarelativistic energies. Assuming that the gap is immersed in a dense soft ...

Phospholipase C-gamma (PLC-gamma) and GTPase activating protein (GAP) are substrates of EGF, PDGF and other growth factor receptors. Since either PLC-gamma or GAP also bind to the activated receptors it was suggested that their SH2 domains are mediating this association. We attempted to delineate the specific region of the EGF receptor that is responsible for the binding, utilizing EGF receptor...

Purpose: The aim of this study was to evaluate the effect of two gingival finishing lines (90° shoulder and deep chamfer) on the marginal fitness of two types of full anatomic all-ceramic crowns; zirconia crowns (Zikonzhan) and glass ceramic crowns (IPS e-max CAD) milled with CAD/CAM system. Materials and Methods: Two dentoform teeth of left maxillary first molar were prepared with chamfer fini...

We examined the dynamics of connexins, E-cadherin and α-catenin during gap-junction disassembly and assembly in regenerating hepatocytes by immunofluorescence microscopy, and immunogold-electron microscopy using SDS-digested freeze-fracture replicas. The present findings suggest that during the disappearance of gap junctions most of the gap junction plaques are broken up into smaller aggregates...

The energy source of a pulsar's non-thermal emission is the rotational energy loss of the neutron star. The rotational energy of the neutron star is transformed into the pulsar radiation by a long sequence of processes. The processes of this sequence are discussed. 1. Introduction The current sample of radio pulsars contains about six hundred pulsars (e.g., Taylor et al. 1993). The radio lumino...