introduction: depression as a disorder is relatively common in all societies several factors are involved in depression development, that shift work is one of these factors. this study compared the frequency of depression in different shifts of nurses in hospitals of yazd university of medical sciences. materials & methods: this study is a descriptive analytical study. based on statistical meth...

In frequency hopping communication, time delay and Doppler shift incur interference. With the escalating upgrading of complicated interference, in this paper, time-frequency two-dimensional (TFTD) partial Hamming correlation (PHC) properties wide-gap frequency-hopping sequences (WGFHSs) with are discussed. A bound on maximum TFTD auto-correlation (PHAC) two bounds PHC WGFHSs got. Li-Fan-Yang pa...

The improvement of sensitivity in quartz crystal microbalance (QCM) applications has been addressed in the last decades by increasing the sensor fundamental frequency, following the increment of the frequency/mass sensitivity with the square of frequency predicted by Sauerbrey. However, this sensitivity improvement has not been completely transferred in terms of resolution. The decrease of freq...

Coupled nonlinear equations that describe the nonlinear process of stimulated Raman scattering in optical fibers are derived. These equations account in a unified manner for the Raman amplification, the Stokes generation, the induced self-frequency shift, and the interpulse stimulated Raman-scattering-induced crossfrequency shift. The equations reduce to a well-known form for relatively wide pi...

Previous studies have shown that adaptation to a sinusoidal grating raises the contrast threshold for detecting gratings of similar spatial frequency and causes a shift in the apparent frequency of gratings of neighboring spatial frequency. In the present study the threshold rise and frequency shift were studied under two conditions: after adapting to a grating (successive condition) and while ...

Perturbation theory is used to calculate the frequency shift of acoustic modes of an homogeneous turbulent fluid and the frequency shifts of solar modes due to turbulent convection. For sound waves in a random flow, the fractional frequency shift is +(11/30)M in the long-wavelength limit, and the shift at short wavelengths is −(2/3)M2, where M is the average Mach number of the flow. In our mode...

We calculate the self-frequency shift experienced by a soliton in a dispersion-managed fiber that is due to the Raman effect, as well as the energy and frequency shifts that result from a collision of such solitons with different wavelengths. We find that dispersion management suppresses both types of frequency shift but does not significantly affect the energy shift that is accumulated over a ...

In this paper altitude measurement from water surface using laser beam is presented. Research data indicate that the reflection of infrared waves from water surface is about zero and it is less than 2% for visible radiations. Phase-shift and heterodyne technique was used for the measurement, and the laser beam ( mW p nm 10 , 700 = = l ) was modulated by a sine wave having a fixed frequency....