Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 19 of 19 for “"decibels"”.
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Reducing the decibels of noise produced by the wood planer in the shop of the Vocational Agriculture Department
… operating and surfacing noise to eighty-five decibels of audible sound revealed that the acoustical treatments would reduce the noise level in the shop. Eighty-five decibels of sound was the established federal safety level at which continuous exposure of the unprotected ear to the noise would …
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Enhancement of temporal and spatial resolution of 2-D reflection data: application to Texaco data over Venice Dome in Plaquemines Parish, Louisiana
… pre-stack data are enhanced by a maximum of 14 decibels between 10 and 58 Hz after SAGC and 4 decibels between 17 and 58 Hz after deconvolution. Signal enhancement improves reflector amplitude to optimize hyperbola collapse through migration. MEE expands the migration cone spatially by 3,503.7 m …
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A Comparative Study of Insertion Loss of Traffic Noise Barriers in Georgia
… was measured as noise difference in A-weighted decibels (dBA) immediately before and after the barriers. The insertion loss was then evaluated by correlating with noise barrier types and other influential variables, including the separation distance of barriers from traffic, the level of …
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Binaural interactions in the auditory midbrain with bilateral electric stimulation of the cochlea
… ranges of ITD sensitivity limited to a few decibels. Consistent with behavioral results in bilaterally implanted humans, neural ITD discrimination thresholds degraded with increasing pulse rates above 100 pulses per second (pps).
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The design and implementation of a wideband digital radio receiver
… with a spurious-free dynamic range exceeding 80 decibels below carrier (dBc). The results achieved reflect favourably on the digital receiver architecture. While the necessity for minimal analogue circuitry will possibly always exist, digital radio architectures are currently able to compete with …
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Non-Destructive Bridge Deck Condition Assessment with a Probability-Based Deterioration Threshold
… data representing different underlying physics, (decibels for ground penetrating radar and volts for half-cell potential), making data interpretation and comparison difficult for bridge owners and practitioners. The deterioration threshold, or the transition between healthy and deteriorated areas, …
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The impact of Rayleigh fading channel effects on the RF-DNA fingerprinting process
… For a signal-to-noise ratio greater than 21 decibels, an average percent correct classification of more than 95% was achieved in a two-reflector channel.
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The Development and Role of Peripheral Auditory Structures in <i>Otocinclus affinis</i>
… increased hearing thresholds by 19 – 23 decibels (dB). I then tested the role of the compound pterotic bone fenestrae in hearing by covering them with a tissue adhesive (n-butyl cyanoacrylate) and recording the hearing thresholds. Covering fenestrae increased hearing thresholds by 4 – 11 …
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Azimuth Modulation of the Radar Backscatter at Near-Normal Incidence
… shows from a fraction of a decibel to up to 10 decibels of azimuth modulation, depending on the surface conditions. In this thesis, a physical optics approach is used with a two-dimensional surface model to derive the electromagnetic backscatter from the ocean surface. If the waves on the ocean …
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The prevalence of hearing loss in HIV-infected South African adolescents on antiretroviral therapy
… air-conduction (AC) thresholds above 30 decibels (dB) were considered to be indicative of debilitating hearing loss. Statistical analysis included univariate analysis and multivariate logistic regression. Results: The cross-sectional analysis included data from 540 participants; …
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Digital Terrain Models for Radio Path Loss Calculations
… to within a radio path loss error of ± 6 decibels; and<br/>(vi) be as computationally efficient as the regular grid.<br/><br/>This research focuses on the implementation of a number of prototype DTMs, including a regular grid, sub-sampled grids, variable density grids, elevation difference …
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Listening to urban sound: A mixed-method approach for understanding human mobility, individual sound exposure, and psychological well-being
… aspects that can be measured in terms of decibels but also socio-psychological aspects that are subjectively perceived by individuals. Urban sound should not merely be considered as an environmental pollutant. Instead, it can be therapeutic resources for human health. Further, individuals’ …
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Evolving subglacial water systems in East Antarctica from airborne radar sounding
… brighter than their surroundings by at least two decibels (relatively bright), and are both consistently reflective (specular) and have a reflection coefficient greater than --10 decibels (absolutely bright). Dim lakes are relatively bright and specular but not absolutely bright, possibly …
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Audit of outcomes of endoscopic cholesteatoma ear surgery
… was 40dB compared to a preoperative mean of 50,3 decibels (dB). In the Groote Schuur group, 23 underwent an exclusive endoscopic approach; 42 had a CWU, 40 had a CWD and 5 had a combined endoscopic-microscopic approach. Overall recidivism rate for the above 13 year old group was 17% (19/110). Of …
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Global development, acoustic and emissive consequences of hydropower
… (~0.0315 kHz) may increase by up to 30 decibels. Similarly, sound pressure levels of riffles increase by up to 16 decibels in the low to mid frequencies (~0.250 kHz). Overall, the findings of this thesis have a number of implications for river catchment management. Hydropower …
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Effects of Earplug Material, Insertion Depth, and Measurement Technique on Hearing Occlusion Effect
… the other a self vocal utterance of "EE" to 65 decibels A-weighted (dBA). The attenuation capability of the medical balloon- based earplugs were tested via monaural Real-Ear-Attenuation-at-Threshold (REAT) test per ANSI S3.19-1974 and compared to that of a Peltor H10A earmuff. Experimental …
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Trailing-Edge Blowing of Model Fan Blades for Wake Management
… baseline blades are directly comparable in decibels. The optimum blowing rate for the simple blowing blades is clearly 2.5%, since this rate shows the most potential tone noise reduction. The Kuethe vane blades suggest decreases in tone noise over all of the tested blowing rates.
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An Experimental Investigation of Unsteady Surface Pressure on Single and Multiple Airfoils
… < 10 a reduction in unsteady lift of up to 7 decibels (dB) occurs while an increase occurs for reduced frequencies > 10 as the angle of attack is increased. The reduction in unsteady lift at low reduced frequencies with increasing angle of attack is a result that has never before been shown …
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Hlukoměr a detektor zvuků
Práce se zabývá návrhem a konstrukcí hlukoměru, který vyjadřuje míru hluku pomocí hladiny akustického tlaku. Pro měření hluku je možné nastavit jeden ze dvou váhových filtrů typu A nebo C zohledňujících vlastnosti lidského sluchu, dále je možné přepínat mezi režimy Fast a Slow v závislosti na …