Recently there has been a great interest in the ability to relate the hydro-mechanical properties of soils to their acoustic response. This ability could enhance high resolution non-destructive evaluation of the shallow subsurface, and would have applications in a variety of fields including groundwater and contaminant hydrogeology, oil recovery, soil dynamics, and the detection of buried objects. Groundwater hydrologists and environmental engineers are challenged with the task of characterizing the material, mechanical and hydraulic properties of the subsurface with limited information generally collected from discrete points. Geophysical testing offers a suite of measurement techniques that allow for the non destructive evaluation of potentially large areas in a continuous manner. Acoustic testing is one geophysical method used by many professions to characterize the subsurface. Unsaturated and multiphase flow modeling relies on the relationship between the capillary pressure and the level of saturation of the porous media. It has been previously suggested that this relationship may be non-unique and rate dependent. A theory which relates this dynamic relationship to the acoustic properties of the soil was developed by others. This research attempts to experimentally verify this theory by meeting the following three objectives: (1) develop an apparatus and procedure to collect acoustic waveforms on laboratory sized unsaturated soil samples, (2) develop a forward modeling technique using a one-dimensional wave propagation model as an alternative analysis method for waves collected on relatively small laboratory specimens, and (3) apply the theory to the measured acoustic data in an attempt to predict the dynamic behavior of the capillary pressure relationship. The acoustic data collected showed variation in compressional wave velocity and attenuation with saturation, and the trends were consistent with data collected by others in partially saturated rocks. The forward modeling technique was shown to provide objective results with reasonable accuracy and low computational time. The dynamic effects predicted with these acoustic measurements did not sufficiently explain the dynamic behavior seen in the laboratory. This is attributed to other causes of significant attenuation not accounted for in the wave propagation theory that was evaluated.

"The hazard associated with dust deflagrations has increased over the last decade industries that manufacture, transport, process, or use combustible dusts. Identification of the controlling parameters of dust deflagration mechanisms is crucial to our understanding of the problem. The objective of this study is to develop an experimental platform, called the Hybrid Flame Analyzer (HFA), capable of measuring the laminar and turbulent burning velocity of gas, dust, and hybrid (gas and dust) air premixed flames as a function of properties specific to the reactants such as dust-particle size and concentration. In this work the HFA is used to analyze a particle-gas-air premixed system composed of coal dust particles (75-90 µm and 106-120 µm) in a premixed CH4-air ( = 0.8, 1.0 and 1.2) flame. This work ultimately aims to improve the knowledge on fundamental aspects of dust flames which is essential for the development of mathematical models. This study is the first of its kind where multiple different parameters that govern flame propagation (initial particle radius, particle concentration, gas phase equivalence ratio, turbulent intensity, and integral length scale) are systematically analyzed in a spatially uniform cloud of volatile particles forming a stationary flame. The experiments show that the turbulent burning velocity is more than two-times larger than the laminar counter-part for each and every case studied. It is observed that smaller particles and larger concentrations (> 50 g/m3) tend to enhance the turbulent burning velocity significantly compared to larger particle sizes and lower concentration ranges. The experimental data is used to develop a correlation similar to turbulent gas flames to facilitate modeling of the complex behavior. "

"Passive scalar concentration and velocity fields of isolated turbulent puffs were examined experimentally using the planar laser Mie scattering and PIV techniques, respectively. Work in WPI laboratories on reacting, fully-modulated jets has indicated significantly reduced flame lengths for compact puffs in comparison with steady and pulsed jets. Of particular interest is the entrainment and mixing of isolated turbulent puffs away from the nozzle. The present experiments were carried out in order to enhance fundamental understanding of the velocity fields associated with isolated, turbulent puffs. Puffs were generated by injecting air through a 5 mm diameter nozzle into a flow chamber with a weak co-flow. The injection time was varied by the use of a fast-response solenoid valve from 20 ms to 161 ms. Puffs with a Reynolds number of 5,000 were examined in the range of 25 - 75 diameters downstream of the nozzle. The results indicate that as the injection volume increases, puffs evolve from a spherical geometry to one with a tail. The distribution of a passive scalar within the examined turbulent puffs is unlike that in turbulent vortex rings. The half-width of radial concentration profile through the puff center decreases as the injection volume increases. On the other hand, the puff length in the axial direction increases with the injection volume. The results from phase-locked PIV measurements indicate that the largest axial mean velocities and the radial velocity fluctuation are within the central portion of the puff and the largest axial velocity fluctuation are typically present above the puff center. The turbulent shear stress profiles within puffs are antisymmetric about the centerline and the maximum magnitude for the smallest injection volume is 2.5 times the steady jet value. The vorticity fields calculated from phase-locked velocity field data indicate the presence of vorticity throughout the puff volume. The ratio of puff volume flow rate to steady jet at the puff center location was largest for the smallest injection volume. The majority of entrainment into the puff occurs below the puff center while the puff cap pushes out into surrounding fluid. In general, the puff characteristics did not reveal an internal structure analogous to that in the turbulent vortex ring."

"This study investigates the interaction of micron- sized coal particles entrained into lean methane €“ air premixed flames. In a typical axisymmetric burner, coal particles are made to naturally entrain into a stream of the premixed reactants using an orifice plate setup. Pittsburgh seam coal dust, with three particle sizes in the range of 0 to 25 µm, 53 to 63 µm, and 75 to 90 µm is used. The effects of different coal dust concentrations (10 €“ 300 g/m3) at three lean equivalence ratios, ϕ (methane-air) of 0.75, 0.80 and 0.85 on the laminar burning velocity are determined experimentally. The laminar burning velocity of the coal dust-methane-air mixture is determined by taking a shadowgraph of the resulting flame and using the cone-angle method. The results show that the addition of coal dust in methane-air premixed flame reduces the laminar burning velocity at particle size of 53 to 63 µm and 75 to 90 µm. However, burning velocity promotion is observed for 0 to 25 µm particles at ϕ = 0.80. Two competing effects are assumed involved in the process. The first is burning velocity promotion effect that the released volatile increases the gaseous mixture equivalence ratio and thus the burning velocity. The second is the heat sink effect of the coal particles to reduce the flame temperature and accordingly the burning velocity. A mathematical model is developed based on such assumption and it can successfully predict the change of laminar burning velocity at various dust concentration. Furthermore, the implication of this study to coal mine safety is discussed."

Cílem práce je zobrazit vývoj webových aplikací na platformě Java, představit javovské webové frameworky Struts, WebWork, Velocity a Tapestry, vytvořit metodiku pro porovnání těchto frameworků a porovnat je podle metodiky tak, aby si čtenář mohl zvolit framework, který bude jeho aplikaci nejlépe vyhovovat. První část, která končí kapitolou číslo tři, popisuje vývoj webových aplikací od počátku až k javovským webovým frameworkům a představí zkoumané frameworky. Pro konkrétní představu jsou zde popsány programy naprogramované ve všech frameworcích. Ve druhé části je vytvořena metodika a frameworky jsou podle ní porovnány. Na závěr jsou shrnuta pozitiva i negativa daných frameworků.

The purpose of this study was to determine the relationship between the Minimal Velocity Threshold (MVT) of 1RM and repetitions until failure testing conditions using the back squat exercise. Fourteen injury-free males with experience in the back squat volunteered to perform a 1RM and a submaximal (70% 1RM) repetitions until failure test, each during different testing sessions. Mean Concentric Velocity (MCV) was collected using a wireless inertia-measuring device. The last successful repetition in either condition was considered the MVT. A very small relationship between 1RM and repetitions until failure MVT was found (r=-0.135). There were no significant differences between testing sessions and the effect size was small (Cohen’s d=0.468) between each testing session. The small relationship and the non-significant p-value might suggest there is individual variance with MVT. In conclusion, the results of this study do not support a general MVT for the back squat comparing 1RM and submaximal repetitions until failure.

No description available.

The purpose of air distribution systems for HVAC is tocreate proper air quality and thermal conditions in an occupiedzone. In mixing type air distribution systems air is suppliedinto a room through various types of outlets and distributed byturbulent air jets. These air jets are the primary factorsaffecting room air motion. The ASHRAE handbook recognises fourmajor zones of maximum velocity decay along a jet. Although numerous theoretical and experimental studies havebeen conducted to develop turbulent air jet theory from the1930's, air jet performance in the further field from theoutlet is still not well understood. Many studies were therefore carried out, and the followingconclusions can be drawn from them:     The end centerline velocities of zone 3 for both "free"jet and wall jet could strongly depend on the outletvelocities and room size.     TheK-value of wall jets could be a function of bothoutlet velocities and outlet size.     It is very important to choose suitable sampling time toevaluate jet performance.     CFD can not always be used to predict jet behaviour,especially for the jet with low outlet velocity and in thearea far away from the outlet. However, for a two-dimensionwall jet, CFD could be a powerful tool for designers. <b>KEYWORDS</b>: air jet, centerline velocity,K-velocity, air diffuser, ventilation, measurement,CFD

In patients with chronic kidney disease (CKD), overhydration, uremic toxins and left ventricular (LV) dyssynchrony are factors that may lead to LV dysfunction and conduction abnormalities and thus contribute to the high cardiac mortality. Colour tissue velocity imaging (TVI) allows a detailed quantitative analysis of cardiac function in CKD patients, opening new possibilities to evaluate longitudinal myocardial motion, rapid isovolumetric events, LV filling pressure and LV synchronicity. Aims: Using TVI technique: 1. To evaluate myocardial function disturbances and their relations to risk factors in CKD patients. 2. To assess LV synchronicity in HD patients, both at baseline and after HD, and 3. To study acute cardiac effects of HD and i.v. furosemide in HD patients. Methods: 40 predialysis CKD (stages I, II, III, IV and V) (Study II) and 59 HD (Studies I, III, IV and V) patients were studied. In both groups of patients LV function was evaluated using TVI, and in HD patients LV synchronicity was also assessed using tissue synchronization imaging (TSI). In HD patients the evaluations were performed before and after HD (Studies III and V) and i.v. furosemide infusion (Study IV). Results: 1. TVI detected: a) LV contraction disturbances in CKD patients with LVH and normal ejection fraction. b) An increase of LV contractility after HD. c) No changes in cardiac function induced by furosemide. 2. TSI detected the presence of LV dyssynchrony and its improvement after HD. 3. In CKD, cardiac dysfunction seemed to be related to high levels of PTH, phosphate and blood pressure. Conclusions: TVI is a sensitive tool for studies on cardiac function in CKD, allowing a detailed and accurate evaluation of disturbances in LV function. TVI also provides the possibility to follow the changes in LV function and synchronicity induced by different therapeutical interventions. The obtained information may contribute to a better management of CKD patients. / QC 20100809

Groundwater flow in the capillary fringe is rarely measured during hydrogeological studies because of the difficulties associated with investigating this region. Previous research using a point velocity probe (PVP) to investigate groundwater velocity below the water table suggested that the PVP may also be capable of measuring groundwater velocity within the capillary fringe. The earlier PVP was redesigned for this study to allow for groundwater velocity data to be collected remotely. Using this system, groundwater velocity in the capillary fringe was investigated under field and laboratory conditions. Field experiments to investigate horizontal flow in the capillary fringe were conducted either by collecting vertical velocity profiles across the water table, or by holding the probe stationary and allowing seasonal recharge to move the capillary fringe and water table past the probe. Laboratory experiments were conducted in a controlled flow tank that simulated regions of an aquifer up to 85 cm above the water table. The redesigned PVP performed well as a remote system and provided velocity measurements up to 12 cm above the water table under field conditions. These values were consistent with those measured below the water table. In the laboratory, under conditions of drainage, groundwater velocity measurements in the capillary fringe consistent with values below the water table were measured up to 44 cm above the water table. The ability to measure horizontal flow of groundwater in the capillary fringe may open up new avenues for research in the study of contaminant transport in phreatic aquifers.