in this study, 22 patients (15-75 years old) were selected and transferred to ct scan for tumor ablation. for ablations, after prep and drep under the local anesthesia and mild sedation in proper position, small incision made and special needle inserted and guided by proper direction to the core of the tumor. then, laser probe inserted through the needle and laser energy delivered. although we ...

We discuss the properties of the pentaquark in a collective stringlike model with a nonplanar configuration of the four quarks and the antiquark. In an application to the mass spectrum of exotic Θ baryons, we find that the ground state pentaquark has angular momentum and parity J = 1/2− and a small magnetic moment of 0.382 μN . The decay width is suppressed by the spatial overlap with the decay...

The simultaneous influences of an intense laser field and static electric field on one-electron states and intraband optical absorption coefficient are investigated in two-dimensional GaAs/Ga 0.7Al0.3 As quantum ring. An analytical expression of the effective confining potential in the presence of the external fields is obtained. The one-electron energy levels and wave functions are calculated ...

Executive Summary We propose a program of study of the interaction of electrons and photons in fields approaching the critical QED field strength of an electron rest energy per Compton wavelength. This can be achieved in collisions between the picosecond pulses of a teraWatt laser and a 50-GeV electron beam. The phenomena accessible to study include nonlinear Compton scattering , trident produc...

We examine the spectrum of gravitational radiation emitted by a network of cosmic strings, with emphasis on the observational constraints and the opportunities for detection. The analysis improves over past work, as we use a phenomenological model for the radiation spectrum emitted by a cosmic string loop. This model attempts to include the effect of the gravitational back-reaction on the radia...

Several microwatts of tunable cw radiation near 194 nm in a linewidth of less than 2 MHz have been generated by sum-frequency mixing the radiation from a frequency-doubled argon-ion laser with the radiation from a ring dye laser in a crystal of potassium pentaborate. An external ring cavity resonant with the dye laser gives an enhancement factor of about 14 in the sum-frequency-generated radiat...

We demonstrate a CW random distributed feedback Raman fiber laser operating in a 1.2 μm spectral band. The laser generates up to 3.8 W of the quasi-CW radiation at 1175 nm with the narrow spectrum of 1 nm. Conversion efficiency reaches 60%. Up to 1 W is generated at the second Stokes wavelength of 1242 nm. It is shown that the generation spectrum of RDFB Raman fiber laser is much narrower than ...

In the context of conjugated polymers, especially those of the poly (phenylenevinylene) (PPV) family, which are promising candidates as emission material in light emitting devices such as LEDs, field effect transistors and photovoltaic devices, we have, in the present study, prepared MEH-PPV [Poly [2- methoxy-5-(2’-ethyl-hexyloxy)-1,4-phenylen-evinylene] of low molecular weight and low polydisp...

At room temperature, cobalt oxide cations directly convert methane to methanol with high selectivity but very low efficiency. Two potential intermediates of this reaction, the [HO-Co-CH(3)](+) insertion intermediate and [H(2)O-Co=CH(2)](+) aquo-carbene complex are produced in a laser ablation source and characterized by electronic and vibrational spectroscopy. Reaction of laser-ablated cobalt c...