in the form of passive seismic methods, broadband seismometers have been used in hydrocarbon exploration. the frequency bandwidth typically studied is in the range of 1–6 hz. the observations on low frequency band of microtremors are used to calculate the spectral ratio of vertical and horizontal components (v/h) and power spectral density (psd). attributes based on the v/h ratio and the psd ha...

A 2.4 GHz CMOS RF front-end using for ZigBee application is described. The front-end consists of a low noise amplifier and a down-mixer and uses a 2 MHz IF frequency. A common source with resistive feedback and an inductive degeneration are adopted for a low noise amplifier, and a 20 dB gain control step is digitally controlled. A passive mixer for low current consumption is employed. The RF fr...

Kinetic inductance detectors (KIDs) are a promising technology for low-noise, highly-multiplexible mmand submm-wave detection. KIDs have a number of advantages over other detector technologies, which make them an appealing option in the cosmic microwave background B-mode anisotropy search, including passive frequency domain multiplexing and relatively simple fabrication, but have suffered from ...

in this paper the optimal design of a dissipator made of aluminium and steel and principallysubjected to shear forces and the preliminary results of the characterization tests are described.the device has been designed on the basis of an optimization procedure with the objective tomaximize the energy dissipated in the device. the response of a 3d frame equipped with thedevice and subjected to 7...

background noise exposure is known as a risk factor for hearing loss and one of its effects is noise-induced stress. cortisol as a stress hormone is used in noise-induced stress assessments. objectives the aim of this study was to measure and compare saliva cortisol concentrations in the morning and evening in normal work day and rest day in both case and control groups and to assess the associ...

In this letter, we identify that the analysis in terms of noise multibeam passive beamforming networks requires a proper formulation, order not to overestimate generated by network. We show inherent spatial diversity offered type results an improvement signal-to-noise ratio, similar one obtained digital architectures, with penalty due insertion loss. To illustrate phenomena, two generalized equ...

Passive harmonic mode-locking in soliton fiber laser is presented with excellent noise characteristics by employing a single-walled carbon nanotubes saturable absorber designed to interact with evanescent wave of the laser field. The 34(th) harmonic mode-locking pulses at 943.16 MHz repetition rate were stably generated with 18 mW output power, >50 dB side-mode suppression and -140 dB/Hz relati...