In this study, three voluteless centrifugal fans are compared for their aeroacoustic performances. The tonal noise is predicted by coupling the IDDES with Formulation 1A of Farassat. sources at blade passing frequency (BPF) identified. It found that related to fan inlet gap, which introduces higher velocity intensities and turbulent fluctuations interacting leading edge. By redesigning BPF redu...

BACKGROUND gap detection in 11 and 12-year-old children. AIM to investigate temporal resolution through the Gap in Noise test in children of 11 and 12 years in order to establish criteria of normal development. METHOD participants were 92 children, with ages of 11 and 12 years, enrolled in elementary school, with no evidences of otologic, and/or neurologic, and/or cognitive disorders, as we...

Five normal listeners were tested in detail for their auditory gap-detection thresholds, using stimuli in which the narrow-band noise markers of the gap differed in one or both of two auditory dimensions ~frequency composition and ear stimulated!. Gap thresholds for stimuli in which the markers differed along either single dimension averaged about 18 ms, while thresholds for markers differing a...

Ray-Kuang Lee, Elena A. Ostrovskaya, Yuri S. Kivshar, and Yinchieh Lai Nonlinear Physics Centre and ARC Centre of Excellence for Quantum-Atom Optics, Research School of Physical Sciences and Engineering, The Australian National University, Canberra, Australian Capital Territory 0200, Australia Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, ...

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...

background: in the steel industry, coke-fueled furnaces are used for smelting iron ore to produce cast iron are considered as sources of annoying noise.this study aims to evaluate the noise pollution blast furnace and sound source characteristics in order to present noise control measures in the steel industry. methods: measurement of noise level and its frequency analysis was performed using s...

In wireless channel the noise has a zero mean. This channel property can be used in the enhancement of the noise performance in the digital receivers by oversampling the received signal and calculating the decision variable based on the time average of more than one sample of the received signal. The averaging process will reduce the effect of the noise in the decision variable that will approa...