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Effect of currents and waves on ADCP echo intensityChen, Yu-Cun 13 February 2007 (has links)
In this study, bottom mounted ADCP and RCM 9 were deployed to collect time series data of current, turbidity and acoustic backscattered echo intensity (EI) in the estuarine environment near Love River and in the coastal waters of Howan. Our results indicate that in the torrential rain event, the Love River became very turbid with the flow speed exceeding 1.5 m/s. ADCP EI data also increase rapidly and correlate well with the turbidity data. Based on the empirical formula of Kim and Voulgaris (2003), the EI time series data of the first bin are converted into sediment suspension concentration (SSC), which compared reasonably well with those converted from the optical observations of turbidity. Therefore, ADCP EI data can be used as a good proxy of SSC. Velocity profiles measured by ADCP were also analyzed to obtain the friction velocity and roughness length according to the logarithmic relationship. The log layer height extended to almost full channel depth of 4 m during strong flows, the roughness lengths were about 10-3 m and the bottom shear stress reached 10 Pa. It is not surprising that bottom sediments are stirred under such a large shear stress.
The sediment suspension due to current and wave action in the rather clear coastal waters of Howan is also investigated by means of ADCP EI data. In winters the observed current speed is stronger while the wave height is smaller (Hs<1 m). It is found that the near-bottom ADCP EI data have better correlation with the current magnitude but poorer correlation with surface waves. On the other hand, the ADCP EI data near the sea surface become more dependent on the surface waves. This is possible due to the bubbles entrained by breaking waves, especially under the condition of Hs>0.5 m. In summers the observed current speed is weaker while the wave height is generally higher. In one typhoon event the observed Hs even reached 4.5 m. The calculated maximum orbital velocity at the bottom and bed shear stress generated by surface waves are sufficient to mobilize sediment. The ADCP EI data of the whole water column (about 15 m) correlate nicely with the wave height but correlate poorly with current magnitude. In contrast to the results of the Love River, the near-bottom ADCP EI data show a weak correlation with the turbidity observation.
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A clinical comparison and analysis between conventional MLC based and solid compensator based IMRT treatment techniques [electronic resource] /Khadija, Murshed. January 2009 (has links)
Thesis (M.S.)--University of Toledo, 2009. / "In partial fulfillment of the requirements for the degree of Master of Science in Biomedical Sciences." Title from title page of PDF document. Bibliography: p. 34-35.
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Noise and Vibration Control for a Decanting CentrifugeRandle, Perri January 2011 (has links)
High levels of machine noise result in health issues for those people exposed to the machine for extended periods. Machine noise is becoming a more significant design consideration, often because of legislative requirements.
Decanting centrifuges are machines with a rotating bowl. They have a number of noise sources, the most significant being structural noise, vortex/turbulence noise and siren noise. Due to the size, mass and speed of the rotating bowl, the bowl is the main source of structural noise. The structural noise is produced by all surfaces that are directly coupled to the bowl’s bearings. Due to the speed of rotation of the bowl, the turbulence from the various trailing edges generates broad spectrum vortex noise. Siren noise due to air flow through the bowl also generates significant noise especially at the lower harmonics of the bowl rotation frequency.
Strategies to reduce decanter machine noise include:
• Decoupling the surfaces of the from the main bearings of the rotating bowl and hence reduce the amount of structurally transmitted noise.
• Smoothing the surface of the bowl to minimise the edges that produce vortices that are shed and produce vortex/turbulence noise.
• As siren noise is produced due to flow through the rotating bowl, which is integral to the function of the decanter, the exit ports should be designed so that the noise is produced within parts of the sound spectrum that have low noise levels.
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Intensity discrimination in hearingCarlyon, R. P. January 1984 (has links)
No description available.
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Mutual Diffusion of Poly(4-vinylpyridine) in Chloroform Probed by Quasielastic Light ScatteringChen, Kuo-Wei 01 July 2004 (has links)
A light scattering study of dilute solutions consisting of poly(4-vinylpyridine) dissolved in chloroform has been carried out. Chloroform is a good solvent for P4VP. Dynamic light scattering measurements show only a diffusion mode in the intensity autocorrelation function for freshly prepared solutions, but two modes are present as the solution ages. The two modes found in P4VP/CHCl3 solution both show a clear q dependence, q being the magnitude of the scattering wave vector, thus indicating that both are diffusive modes. For this system, the diffusion coefficient is found to be mainly determined by the osmotic modulus, with the solution stress modulus making a negligible contribution. A decrease of mutual diffusion coefficient with increasing polymer concentration is observed. As the temperature of the solution is lowered, the mutual diffusion coefficient decreases linearly. Extrapolation of the mutual diffusion coefficient to zero yields the critical temperature, at which the P4VP/CHCl3 solution undergoes a phase transition.
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The Study of Laser-Induced Intensity Gratings in Azo-Dye Doped Liquid CrystalsLin, Hsin-chia 12 July 2004 (has links)
The laser-induced holographic grating technique was employed to study the dynamic of the intensity grating formation in the azo-dye doped liquid crystals. The liquid crystal material in this study has several mesomorphic phases: smectic C, smectic A, and nematic. The first order of diffraction in the mesomorphic phases have been investigated by changing the concentration of dye, the polarizations of the writing beams and the probe beam
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The Study of Phase-Intensity Conversion Transmission MethodHuang, Chiao-Cheng 24 June 2000 (has links)
In this thesis, we present the phase-intensity conversion transmission method for the first time. We analyze phase-intensity conversion theory, laser diode noise, and EDFA noise. By experiment, we investigate the impact of the parameters in phase-intensity conversion such as light source linewidth, phase modulation index, dispersion magnitude, and EDFA on the system performance. We successfully demonstrated simultaneous transmission of one AM-VSB channel through intensity modulation and one QAM channel through phase modulation over 10 km single mode fiber using LiNbO3 external modulator. The system performance with CNR of 57~61 dB for the AM-VSB channel and BER of 6.8´10-9 for the QAM channel can be achieved. The demonstration and the experimental results confirm the feasibility of phase-intensity conversion techniques. Potentially, the phase-intensity conversion transmission method could be applied on optical encryption and decryption systems.
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Walking cadence to attain a minimum of moderate aerobic intensity in people at risk of cardiovascular diseasesSerrano, Fagner 29 July 2015 (has links)
Problem: Walking cadence (steps/minute) is used to prescribe walking intensity. For healthy adults, the recommended cadence is generally 100 steps per minute to reach moderate intensity. However, the required walking cadence to reach that intensity for people having risk factors for cardiovascular diseases (CVD) is unknown.
Methods: Ninety-one people presenting risk factors for CVD completed a graded exercise test to assess maximum oxygen consumption. In a separate session, when participants reached moderate intensity based on their maximum oxygen consumption, walking cadence was recorded.
Results: Mean walking cadence to reach moderate intensity was 115.8 ± 10.3 steps per minute. Using linear regression analysis, only body weight (ß=0.24; P=0.018) significantly predicted the walking cadence required to reach moderate intensity.
Conclusions: The walking cadence needed for people presenting risk factors for CVD to reach moderate intensity is about 116 steps per minute. Body weight influences the walking cadence needed to reach moderate intensity. / October 2015
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Comparing the effects of three exercise intensities on the prevention of hypoglycemia in people with type 1 diabetesRempel, Meaghan 01 September 2015 (has links)
The appropriate intensity of exercise needed to reduce the risk of hypoglycemia (≤3.9 mmol/L) in persons with type 1 diabetes (T1D) is not known.
Ten participants with T1D performed four exercise sessions on a treadmill lasting 45 minutes: a control condition at 45-55% of heart rate reserve and three high intensity sessions at 70, 80, and 90% of heart rate reserve. A blinded continuous glucose monitor was used to measure time spent ≤3.9 mmol/L and glucose variability in the 12 hours following exercise.
There were no significant changes in the percentage of time spent ≤3.9 mmol/L (p=0.58) and glucose variability as measured by mean absolute glucose change (p=0.53) and continuous overall net glycemic action (CONGA1: p=0.95; CONGA2: p=0.90; CONGA4: p=0.72) between the sessions.
High intensity exercise at 70, 80, and 90% of HRR does not significantly reduce the amount of time spent ≤3.9 mmol/L or glucose variability compared to the 45-55% session alone. / October 2015
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Reflex eyeblink latency as a function of stimulus intensityBixler, Edward Oren, 1937- January 1965 (has links)
No description available.
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