the dedicated satellite mission goce will sense various small mass variations along its path around the earth. here we study the effect of the earth’s topography and atmosphere on goce data. the effects depend on the magnitude of topographic height, and they will therefore vary by region. as the effect of the atmosphere and topography must be removed from the total gravity anomaly prior to geoi...

Ocean ambient noise is generated in many ways such as from winds, rain and shipping. A technique has recently been developed (Harrison and Simons, J. Acoust. Soc. Am, Vol. 112 no. 4, 2002) that uses the vertical directionality of ambient noise to determine seabed properties. It was shown that taking a ratio of upward looking beams to downward produces an estimate of the reflection loss. This te...

SUMMARY The purpose of marine seismic experiments is to provide information the structure and physical properties subsurface. P-wave velocity distribution most commonly modelled property, usually by inversion arrival times or waveform attributes. In wide-angle reflection/refraction (WAS) experiments, phases identified in data recorded ocean bottom seismometers (OBS) are used image relatively de...

the use of stokes boundary values problems for the determination of the geoid requires that gravity anomalies (as boundary values) are known on geoid (as boundary). while, the gravity observations are measured on the earth's surface, to obtain boundary data, the surface gravity anomalies does are downward from the terrain onto geoid. for downward continuation (dwc) of surface gravity anoma...

Introduction: Hearing loss is one of the most common occupational diseases. In most workplaces, workers are exposed to noise and solvents simultaneously, so the potential risk of hearing loss due to solvents may be attributed to noise.  In this study we aimed to assess the effect of exposure to mixed aromatic solvents on hearing in the absence of exposure to hazardous noise.   Materials and Met...

Perceived continuity was studied by varying the direction (steady-state, upward glide, or downward glide), the frequency separation, and the slope of two sinusoidal tones separated by a louder burst of white noise. When the two tones had different directions, continuity was perceived according to a frequency-proximity principle (frequency-interpolation effect). On the other hand, when the tones...

the modulation response, relative intensity noise and frequency noise characteristics of qd lasers are investigated theoretically, in presence of an additional optical pumping. it is revealed that the modulation response of qd laser enhances under additional optical beam. by small signal analysis of the carriers' and photons' rates, it is proposed that by injecting excess carriers to ...