Results found: 3

Number of results on page

Search results

Sort By:

Limit search:

The Use of the Phase Locking Information in the Human Auditory System for Frequencies Above 5 kHz

100%

Sęk A., Bukała M.

Acta Physica Polonica A

2013

vol. 123

issue 6

1106-1113

Accurate allocation of neural impulses to the same phase (i.e. phase locking) in the auditory system, ceases for frequencies above 5 kHz. However, some recent works suggest that it may have a much higher value. A discrimination of harmonic complex and inharmonic complex sound, formed using sound harmonic complex, in which all components were shifted towards higher frequency by the same number in hertzs, was analyzed. Fundamental frequency was F_0=1 kHz and signals were bandpass filtered by a fixed filter center frequency of which was 11F_0 and bandwidth 5F_0. Discrimination threshold was Δ F=0.089F_0 for 10 normal-hearing subjects. However, replacing the sinusoidal components with the noise bands brought about a significant increase in thresholds. The largest increase was observed for 700 Hz bandwidth. The replacement of sinusoidal components with noisebands reduces information conveyed by phase locking. The differences in excitation pattern for harmonic complex and inharmonic complex signals, for the average threshold, did not exceed 0.7 dB. Therefore they could not be a useful cue for harmonic complex and inharmonic complex discrimination. A simplified model of phase locking showed that the substitution of sinusoids with bands of noise significantly reduced number of intervals between successive neural spikes corresponding to the virtual pitch of harmonic complex and inharmonic complex sounds. This degradation of discrimination suggests that the main source of information about the pitch of harmonic complex and inharmonic complex, especially for sinusoidal components, was the phase locking.

Modeling of Small Diameter Semiconductor Nanowires

81%

Bukała M., Galicka M., Buczko R., Kacman P.

Acta Physica Polonica A

2007

vol. 112

issue 2

425-430

The properties of very thin (up to 16Å diameter) wires, cut out from the bulk in either zinc-blende or wurtzite material, are studied theoretically. In the total energy calculations we use ab initio methods and consider three different crystallographic growth axes for the zinc-blende and one for the wurtzite structure. We show that the most stable zinc-blende nanowires are those growing along (111) direction, however, the wurtzite structure is found to be energetically more favorable than the zinc-blende for wires of the same diameter. In addition, the band structure of the wires was calculated.

Experimental and Theoretical Analysis οf PbTe-CdTe Solid Solution Grown by Physical Vapour Transport Method

42%

Szot M., Szczerbakow A., Dybko K., Kowalczyk L., Smajek E., Domukhovski V., Łusakowska E., Dziawa P., Mycielski A., Story T., Bukała M., Galicka M., Sankowski P., Buczko R., Kacman P.

Acta Physica Polonica A

2009

vol. 116

issue 5

959-961

Bulk monocrystals of Pb_{1-x}Cd_{x}Te, with the Cd content x up to 0.11, were grown by physical vapour transport method. The structural, electrical and optical properties of these ternary crystals were studied experimentally and theoretically. All investigated samples exhibit rock-salt structure and high crystal quality, which was confirmed by X-ray rocking curve width parameter of about 100 arcsec. The decrease of the lattice parameter with increasing Cd content x was found experimentally, in agreement with ab initio calculations. The band structures of Pb_{1-x}Cd_{x}Te mixed crystals for x values up to 0.2 were calculated using tight binding approach. The calculated band gap in the L-point increases with the Cd content in qualitative agreement with photoluminescence measurements in the infrared. For all studied Pb_{1-x}Cd_{x}Te samples, the Hall effect and electrical conductivity measurements, performed in the temperature range from 4 to 300 K, revealed p-type conductivity.

Refine search results

3 Acta Physica Polonica A

1 2013

1 2009

1 2007

3 Bukała M.

2 Buczko R.

2 Galicka M.

2 Kacman P.

1 Domukhovski V.

1 Dybko K.

1 Dziawa P.

1 Kowalczyk L.

1 Mycielski A.

1 Sankowski P.

1 Smajek E.

1 Story T.

1 Szczerbakow A.

1 Szot M.

1 Sęk A.

1 Łusakowska E.

Search results

The Use of the Phase Locking Information in the Human Auditory System for Frequencies Above 5 kHz

Modeling of Small Diameter Semiconductor Nanowires

Experimental and Theoretical Analysis οf PbTe-CdTe Solid Solution Grown by Physical Vapour Transport Method