Search results for "ACOUSTIC"
showing 10 items of 1590 documents
Enhanced prediction of multipaction breakdown in passive waveguide components including space charge effects
2008
An enhanced prediction software tool of multipaction breakdown effect in passive waveguide components is proposed in this work. For such purpose, the space charge field effects are included employing a particle-in-cell code and finite differences in time domain integration techniques. As a result, the novel prediction tool models all the physical effects derived from multipactor such as reflected power, noise and/or harmonics, thus improving the accuracy of the threshold predictions and providing very valuable additional information of the phenomena. Such tool has been integrated within a full-wave modal analysis software for complex waveguide geometries (FEST3D), and the multipactor effect…
Key processing precedes emotional categorization of Western music.
2005
To investigate whether key processing precedes the appraisal of valence in music, participants listened to pairs of clips of same or different valence, played either in the same key or one semitone apart. They judged whether the second clip expressed the same emotion as the first one. Our predictions were confirmed: the response times obtained were shorter when both clips were played in the same key than when they were played one semitone apart.
New fast mismatch negativity paradigm for determining the neural prerequisites for musical ability.
2011
Studies have consistently shown that the mismatch negativity (MMN) for different auditory features correlates with musical skills, and that this effect is more pronounced for stimuli integrated in complex musical contexts. Hence, the MMN can potentially be used for determining the development of auditory skills and musical expertise. MMN paradigms, however, are typically very long in duration, and far from sounding musical. Therefore, we developed a novel multi-feature MMN paradigm with 6 different deviant types integrated in a complex musical context of no more than 20 min in duration. We found significant MMNs for all 6 deviant types. Hence, this short objective measure can putatively be …
Informal musical activities are linked to auditory discrimination and attention in 2-3-year-old children: an event-related potential study
2012
The relation between informal musical activities at home and electrophysiological indices of neural auditory change detection was investigated in 2-3-year-old children. Auditory event-related potentials were recorded in a multi-feature paradigm that included frequency, duration, intensity, direction, gap deviants and attention-catching novel sounds. Correlations were calculated between these responses and the amount of musical activity at home (i.e. musical play by the child and parental singing) reported by the parents. A higher overall amount of informal musical activity was associated with larger P3as elicited by the gap and duration deviants, and smaller late discriminative negativity r…
Silent music reading: Amateur musicians' visual processing and descriptive skill
2013
This article addresses the silent reading of music notation, combining eye-movement measures with a semantic analysis of readers’ verbal descriptions of the notated music. A group of musical novices ( n = 16) and two groups of musical amateurs (less experienced n = 11 and more experienced n = 10) participated in three separate measurement sessions during a nine-month-long university music course designed for future primary-school teachers. In each session they viewed a notated folk song for 30 s and then described what they had seen. Greater musical experience was found to be connected with shorter fixation durations, more linear scanning of the notated music, and more accurate and integra…
Ligand removal from soluble CdTe nanocrystals evidenced by time-resolved photoluminescence spectroscopy
2008
We present experimental studies on the effect of pyridine treatment on the optical properties of ligand-stabilized colloidal CdTe nanocrystals. We demonstrate, by quasi-stationary and time-resolved photoluminescence (PL) spectroscopy, a drastic reduction in the PL lifetime and a concomitant decrease in the PL yield by more than 90% when dissolving the nanocrystals in pyridine. The pyridine solvent efficiently removes the ligand shell and thus enables a rapid energy transfer from the quantum dot to optically dark surface states or into the solvent. The demonstrated removal of the ligand shell is a key step towards integrating such CdTe nanocrystals in hybrid organic/inorganic nanocomposites,…
Lateral force microscopy of multiwalled carbon nanotubes
2009
Carbon nanotubes are usually imaged with the atomic force microscope (AFM) in non-contact mode. However, in many applications, such as mechanical manipulation or elasticity measurements, contact mode is used. The forces affecting the nanotube are then considerable and not fully understood. In this work lateral forces were measured during contact mode imaging with an AFM across a carbon nanotube. We found that, qualitatively, both magnitude and sign of the lateral forces to the AFM tip were independent of scan direction and can be concluded to arise from the tip slipping on the round edges of the nanotube. The dependence on the normal force applied to the tip and on the ratio between nanotub…
Radiofrequency volumetric tissue reduction (RFVTR) of inferior turbinates: a new method in the treatment of chronic nasal obstruction.
2001
Twenty-two Caucasians (16 male and 6 female) with chronic bilateral nasal obstruction due to hypertrophic inferior turbinates were followed up over a three-month period. They were assessed by clinical examination, as active anterior rhinometry, and acoustic rhinometry before and after topical decongestion, preoperatively and three months after surgery. All patients were treated by application of radiofrequency-volumetric-tissue reduction (RFVTR, or somnoplasty) to both inferior turbinates. Initial postoperative edematous response disappeared during the first week after RFVTR. Three months postoperatively 20 of 22 patients (91%) reported subjective improvement of nasal patency. The average …
Acoustic rhinometry in pre-school children.
1993
Acoustic rhinometry was performed in 35 normal nose-breathing children between 3 and 6 years. The average cross-sectional areas at the nasal valve, at the anterior end of the turbinates, and in the nasopharynx were 0.34 +/- 0.06 cm2, 0.35 +/- 0.08 cm2 and 1.37 +/- 0.48 cm2 respectively. The average minimal cross-sectional area was 0.29 +/- 0.06 cm2. The minimal cross-sectional area was located at the nasal valve in 14 and at the anterior end of nasal turbinates in 21 of the 35 children. As would be expected, the cross-sectional areas at different sites of the nasal cavity increased with increasing age of the children. But, whereas the minimal cross-sectional area increased by 0.024 cm2 per …