Search results for "NOISE"
showing 10 items of 1375 documents
Survey of the Working Condition of Used Tractors in Northern Italy
1995
The working condition of 96 used tractors of different ages and sizes was examined in Northern Italy and compared with those of new machines and the standards at present in force. The results show that from the safety point of view, performance levels do not worsen drastically with increase in vehicle age. Rusty roll-over protective structures with cracks and tears are the main danger. Controls which are difficult to operate, seats in very bad condition, high levels of noise and vibrations render the situation critical from the ergonomic point of view.
Noise contribution to resonance phenomena and information propagation in non linear electronic networks
2015
This manuscript presents research aiming to show possible positive effects of deterministic and stochastic perturbations on the responses of different nonlinear systems. To that end, both numerical and experimental studies were carried out on two kinds of structures : an elementary electronic FitzHugh-Nagumo oscillator and an electrical line developed by resistively coupling 45 elementary cells. In the first section, the elementary cell characterization was undertaken in a deterministic regime. In the presence of a bichromatic stimulus, it is shown that when the low frequency component is subthreshold, its detection can be maximized for an optimal magnitude of the second component thanks to…
Trokšņa līmeņa novērtējums iekštelpās
2017
Bakalaura darba “Trokšņa līmeņa novērtējums iekštelpās” ietvaros veikti trokšņa līmeņa mērījumi daudzdzīvokļu māju dzīvojamās telpās dažādās Rīgas apkaimēs - Bolderājā, Vecrīgā un Maskavas forštatē. Novērtējums veikts izmantojot tiešo mērījumu metodi ar kalibrētu iekārtu PCE-322A. Iegūtie rezultāti apkopoti izvērtējot diennakts cikliskumu, mainību nedēļas laikā, ārējo faktoru ietekmi, kopā veiktas 8 mērījumu kampaņas. Iegūtie rezultāti liecina par normatīviem atbilstošu akustiskā trokšņa līmeni dzīvojāmo ēku telpās, kas nozīmē, ka tiek nodrošināta cilvēku aizsardzība pret akustiskā trokšņa nelabvēlīgo iedarbību.
Vitamin A deficiency increases noise susceptibility in guinea pigs.
1990
The effect of vitamin A deficiency in guinea pigs on noise-induced temporary threshold shift (TTS) was evaluated after short (15 min) acoustic overstimulation with a moderate (90 dB) broad-band white noise. Some guinea pigs were fed ad libitum a purified diet deficient in vitamin A (VAD group) until biochemical signs of deficiency occurred. A second, control group (VA group) received the same diet as well as 100 IU vitamin A daily by pharyngeal tube. Cochlear potentials were recorded by special computerized equipment using implanted electrodes. Before acoustic stimulation, a baseline value was determined with a test stimulus [90 dBA (A-filter according to usual DIN instructions)] correspond…
Ascorbic acid reduces noise-induced nitric oxide production in the guinea pig ear.
2008
Objectives: Noise-induced hearing loss can be caused, among other causes, by increased nitric oxide (NO) production in the inner ear leading to nitroactive stress and cell destruction. Some studies in the literature suggest that the degree of hearing loss (HL) could be reduced in an animal model through ascorbic acid supplementation. To identify the effect of ascorbic acid on tissue-dependent NO content in the inner ear of the guinea pig, we determined the local NO production in the organ of Corti and the lateral wall separately 6 hours after noise exposure. Study Design: Prospective animal study in guinea pigs. Methods: Over a period of 7 days, male guinea pigs were supplied with minimum (…
Influence of Silence and Noise Filtering on Speech Quality Monitoring
2021
With the exponential increase of mobile users and internet subscribers, the utilization of voice over internet protocol (VoIP) application is increasing dramatically. People exploit different VoIP applications for effective communication, for example, Google Meet, Microsoft Skype, Zoom video conferencing applications, etc. The single-ended speech quality metrics are employed for measuring and monitoring the quality of speech. However, different types of degradations present in the surroundings distort the quality of speech. In order to meet the desired quality of experience (QoE) level of end-user while using VoIP applications, it is necessary to reduce VoIP degradations and obtain the opti…
Road traffic detection using wireless noise sensors
2012
In this paper we present our experimental result of using wireless noise sensor network (WNSN) to detect road traffic. With the features implemented in our network such as multipoint measuring, synchronization, real-time data availability, and strict compliance of sound level meter (SLM) standard IEC 61672:2003, we assert the possibility of using WNSN to detect road traffic, such as vehicle amount, size, and velocity. This application can be extended and integrated as a part of Intelligent Transportation System (ITS).
Simultaneous ranging and self-positioning in unsynchronized wireless acoustic sensor networks
2016
Automatic ranging and self-positioning is a very desirable property in wireless acoustic sensor networks, where nodes have at least one microphone and one loudspeaker. However, due to environmental noise, interference, and multipath effects, audio-based ranging is a challenging task. This paper presents a fast ranging and positioning strategy that makes use of the correlation properties of pseudonoise sequences for estimating simultaneously relative time-of-arrivals from multiple acoustic nodes. To this end, a proper test signal design adapted to the acoustic node transducers is proposed. In addition, a novel self-interference reduction method and a peak matching algorithm are introduced, a…
Resonant activation in polymer translocation: new insights into the escape dynamics of molecules driven by an oscillating field
2010
The translocation of molecules across cellular membranes or through synthetic nanopores is strongly affected by thermal fluctuations. In this work we study how the dynamics of a polymer in a noisy environment changes when the translocation process is driven by an oscillating electric field. An improved version of the Rouse model for a flexible polymer has been adopted to mimic the molecular dynamics, by taking into account the harmonic interactions between adjacent monomers and the excluded-volume effect by introducing a Lennard–Jones potential between all beads. A bending recoil torque has also been included in our model. The polymer dynamics is simulated in a two-dimensional domain by num…
Translocation time of periodically forced polymer chains.
2010
6 páginas, 11 figuras.-- PACS number(s): 36.20.-r, 05.40.-a, 87.15.A-, 87.10.-e