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Sample records for laboratory experimental investigation

  1. Laboratory investigations

    Our task is to design mined-repository systems that will adequately secure high-level nuclear waste for at least 10,000 yr and that will be mechanically stable for 50 to 100-yr periods of retrievability during which mistakes could be corrected and a valuable source of energy could be reclaimed, should national policy on the reprocessing of spent fuel ever change. The only credible path for the escape of radionuclides from the repository to the biosphere is through ground-water, and in hard rock, bulk permeability is largely governed by natural and artificial fracture systems. Catastrophic failure of an excavation in hard rock is likely to occur at the weakest links - the discontinuities in the rock mass that is perturbed first by mining and then by radiogenic heating. The laboratory can contribute precise measurements of the pertinent thermomechanical, hydrological and chemical properties and improve our understanding of the fundamental processes through careful experiments under well controlled conditions that simulate the prototype environment. Thus laboratory investigations are necessary, but they are not sufficient, for conventional sample sizes are small relative to natural defects like joints - i.e., the rock mass is not a continuum - and test durations are short compared to those that predictive modeling must take into account. Laboratory investigators can contribute substantially more useful data if they are provided facilities for testing large specimens(say one cubic meter) and for creep testing of all candidate host rocks. Even so, extrapolations of laboratory data to the field in neither space nor time are valid without the firm theoretical foundations yet to be built. Meanwhile in-situ measurements of structure-sensitive physical properties and access to direct observations of rock-mass character will be absolutely necessary

  2. Laboratory experimental investigations of braid theory using the rotor-oscillator flow

    Filippi, Margaux; Atis, Séverine; Allshouse, Michael; Jacobs, Gustaaf; Budišić, Marko; Thiffeault, Jean-Luc; Peacock, Thomas

    2015-11-01

    Interpreting ocean surface dynamics is crucial to many areas of oceanography, ranging from marine ecology to pollution management. Motivated by this, we investigated the braid theory method to detect transport barriers bounding coherent structures in two-dimensional flows. Whereas most existing techniques rely on an extensive spatiotemporal knowledge of the flow field, we sought to identify these structures from sparse data sets involving trajectories of a few tracer particles in a two-dimensional flow. We present the results from our laboratory experiments, which were based on investigations using the rotor-oscillator flow, as a stepping stone towards oceanic applications.

  3. A Laboratory Investigation of Supersonic Clumpy Flows: Experimental Design and Theoretical Analysis

    Poludnenko, A. Y.; Dannenberg, K. K.; Drake, R. P.; Frank, A.; Knauer, J.; Meyerhofer, D. D.; Furnish, M.; Asay, J. R.; Mitran, S.

    2004-03-01

    We present a design for high energy density laboratory experiments studying the interaction of hypersonic shocks with a large number of inhomogeneities. These ``clumpy'' flows are relevant to a wide variety of astrophysical environments, including the evolution of molecular clouds, outflows from young stars, planetary nebulae, and active galactic nuclei. The experiment consists of a strong shock (driven by a pulsed-power machine or a high-intensity laser) impinging on a region of randomly placed plastic rods. We discuss the goals of the specific design and how they are met by specific choices of target components. An adaptive mesh refinement hydrodynamic code is used to analyze the design and establish a predictive baseline for the experiments. The simulations confirm the effectiveness of the design in terms of articulating the differences between shocks propagating through smooth and clumpy environments. In particular, we find significant differences between the shock propagation speeds in a clumpy medium and those in a smooth one with the same average density. The simulation results are of general interest for foams in both inertial confinement fusion and laboratory astrophysics studies. Our results highlight the danger of using average properties of inhomogeneous astrophysical environments when comparing timescales for critical processes, such as shock crossing and gravitational collapse.

  4. A Laboratory Investigation of Supersonic Clumpy Flows: Experimental Design and Theoretical Analysis

    Poludnenko, A Y; Drake, R P; Frank, A; Knauer, J P; Meyerhofer, D D; Furnish, M; Asay, J R

    2004-01-01

    We present a design for high energy density laboratory experiments studying the interaction of hypersonic shocks with a large number of inhomogeneities. These ``clumpy'' flows are relevant to a wide variety of astrophysical environments including the evolution of molecular clouds, outflows from young stars, Planetary Nebulae and Active Galactic Nuclei. The experiment consists of a strong shock (driven by a pulsed power machine or a high intensity laser) impinging on a region of randomly placed plastic rods. We discuss the goals of the specific design and how they are met by specific choices of target components. An adaptive mesh refinement hydrodynamic code is used to analyze the design and establish a predictive baseline for the experiments. The simulations confirm the effectiveness of the design in terms of articulating the differences between shocks propagating through smooth and clumpy environments. In particular, we find significant differences between the shock propagation speeds in a clumpy medium comp...

  5. Active pCO2-Control of Seawater Culture Systems for Laboratory-Based Biogeochemical Experimentation Investigating Global Ocean Acidification

    Hintz, C. J.; Chandler, G. T.; Shaw, T. J.; McCorkle, D. C.

    2007-12-01

    The large-scale effects of anthropogenic CO2 rise and global ocean acidification on calcifying and photosynthetic organisms are not well understood. This ongoing uncertainty fundamentally limits our ability to fully understand global carbon cycling. Field-based studies are limited to the current environmental chemistries observed throughout the world's oceans - a prohibitively resource-intensive platform for manipulative experimentation. Moreover, complex carbonate system equilibria decoupled from the atmosphere are difficult to poise and maintain in laboratory seawater-based experiments lasting longer than a few hours or days. This severely limits the scope of biogeochemical experimentation for simulating past or future ocean chemistries. To address these experimental shortcomings we developed a novel system for the stringent control of pCO2 in culture aeration and seawater. A custom CO2 scrubbing system was designed which removes > 99.8% of atmospheric CO2 at 3-4 L min-1 aeration rate. High precision mass flow controllers integrated with a modular programmable process controller precisely mix high-purity (99.95%) compressed CO2 with the preconditioned CO2-free air stream for aeration into the culture system. Long-term maintenance of experimental CO2 is within ± 2 μatm when operating between 150- 2000 μatm pCO2. The system, in its current configuration, has the ability to simultaneously manipulate and maintain 3 separate carbonate chemistries using aeration pCO2 and seawater alkalinity in independent 400-L seawater reservoirs. Future system expansion can easily maintain 5 or more separate chemistries. The goal of this research is to develop stringent control of seawater carbonate system chemistries for the deep- sea benthic foraminifera cultures housed at the University of South Carolina Arnold School of Public Health. Current experiments are investigating trace metal foraminiferal paleoproxy signatures that appear correlated with [CO32-] very near calcite

  6. Experimental methods for the simulation of supercritical CO2 injection at laboratory scale aimed to investigate capillary trapping

    Trevisan, L.; Illangasekare, T. H.; Rodriguez, D.; Sakaki, T.; Cihan, A.; Birkholzer, J. T.; Zhou, Q.

    2011-12-01

    Geological storage of carbon dioxide in deep geologic formations is being considered as a technical option to reduce greenhouse gas loading to the atmosphere. The processes associated with the movement and stable trapping are complex in deep naturally heterogeneous formations. Three primary mechanisms contribute to trapping; capillary entrapment due to immobilization of the supercritical fluid CO2 within soil pores, liquid CO2 dissolving in the formation water and mineralization. Natural heterogeneity in the formation is expected to affect all three mechanisms. A research project is in progress with the primary goal to improve our understanding of capillary and dissolution trapping during injection and post-injection process, focusing on formation heterogeneity. It is expected that this improved knowledge will help to develop site characterization methods targeting on obtaining the most critical parameters that capture the heterogeneity to design strategies and schemes to maximize trapping. This research combines experiments at the laboratory scale with multiphase modeling to upscale relevant trapping processes to the field scale. This paper presents the results from a set of experiments that were conducted in an intermediate scale test tanks. Intermediate scale testing provides an attractive alternative to investigate these processes under controlled conditions in the laboratory. Conducting these types of experiments is highly challenging as methods have to be developed to extrapolate the data from experiments that are conducted under ambient laboratory conditions to high temperatures and pressures settings in deep geologic formations. We explored the use of a combination of surrogate fluids that have similar density, viscosity contrasts and analogous solubility and interfacial tension as supercritical CO2-brine in deep formations. The extrapolation approach involves the use of dimensionless numbers such as Capillary number (Ca) and the Bond number (Bo). A set of

  7. 3D PiC code simulations for a laboratory experimental investigation of Auroral Kilometric Radiation mechanisms

    Gillespie, K. M.; Speirs, D. C.; Ronald, K.; McConville, S. L.; Phelps, A. D. R.; Bingham, R.; Cross, A. W.; Robertson, C. W.; Whyte, C. G.; He, W.; Vorgul, I.; Cairns, R. A.; Kellett, B. J.

    2008-12-01

    Auroral Kilometric Radiation (AKR), occurs naturally in the polar regions of the Earth's magnetosphere where electrons are accelerated by electric fields into the increasing planetary magnetic dipole. Here conservation of the magnetic moment converts axial to rotational momentum forming a horseshoe distribution in velocity phase space. This distribution is unstable to cyclotron emission with radiation emitted in the X-mode. In a scaled laboratory reproduction of this process, a 75-85 keV electron beam of 5-40 A was magnetically compressed by a system of solenoids and emissions were observed for cyclotron frequencies of 4.42 GHz and 11.7 GHz resonating with near cut-off TE0,1 and TE0,3 modes, respectively. Here we compare these measurements with numerical predictions from the 3D PiC code KARAT. The 3D simulations accurately predicted the radiation modes and frequencies produced by the experiment. The predicted conversion efficiency between electron kinetic and wave field energy of around 1% is close to the experimental measurements and broadly consistent with quasi-linear theoretical analysis and geophysical observations.

  8. 3D PiC code simulations for a laboratory experimental investigation of Auroral Kilometric Radiation mechanisms

    Gillespie, K M; Speirs, D C; Ronald, K; McConville, S L; Phelps, A D R; Bingham, R; Cross, A W; Robertson, C W; Whyte, C G; He, W [SUPA Department of Physics, John Anderson Building, 107 Rottenrow, University of Strathclyde, Glasgow, G4 0NG (United Kingdom); Vorgul, I; Cairns, R A [School of Mathematics and Statistics, University of St Andrews, St Andrews, KY16 9SS (United Kingdom); Kellett, B J [Space Science and Technology Department, STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom)], E-mail: karen.gillespie@strath.ac.uk

    2008-12-15

    Auroral Kilometric Radiation (AKR), occurs naturally in the polar regions of the Earth's magnetosphere where electrons are accelerated by electric fields into the increasing planetary magnetic dipole. Here conservation of the magnetic moment converts axial to rotational momentum forming a horseshoe distribution in velocity phase space. This distribution is unstable to cyclotron emission with radiation emitted in the X-mode. In a scaled laboratory reproduction of this process, a 75-85 keV electron beam of 5-40 A was magnetically compressed by a system of solenoids and emissions were observed for cyclotron frequencies of 4.42 GHz and 11.7 GHz resonating with near cut-off TE{sub 0,1} and TE{sub 0,3} modes, respectively. Here we compare these measurements with numerical predictions from the 3D PiC code KARAT. The 3D simulations accurately predicted the radiation modes and frequencies produced by the experiment. The predicted conversion efficiency between electron kinetic and wave field energy of around 1% is close to the experimental measurements and broadly consistent with quasi-linear theoretical analysis and geophysical observations.

  9. 3D PiC code simulations for a laboratory experimental investigation of Auroral Kilometric Radiation mechanisms

    Auroral Kilometric Radiation (AKR), occurs naturally in the polar regions of the Earth's magnetosphere where electrons are accelerated by electric fields into the increasing planetary magnetic dipole. Here conservation of the magnetic moment converts axial to rotational momentum forming a horseshoe distribution in velocity phase space. This distribution is unstable to cyclotron emission with radiation emitted in the X-mode. In a scaled laboratory reproduction of this process, a 75-85 keV electron beam of 5-40 A was magnetically compressed by a system of solenoids and emissions were observed for cyclotron frequencies of 4.42 GHz and 11.7 GHz resonating with near cut-off TE0,1 and TE0,3 modes, respectively. Here we compare these measurements with numerical predictions from the 3D PiC code KARAT. The 3D simulations accurately predicted the radiation modes and frequencies produced by the experiment. The predicted conversion efficiency between electron kinetic and wave field energy of around 1% is close to the experimental measurements and broadly consistent with quasi-linear theoretical analysis and geophysical observations.

  10. Experimental investigation of the formation and propagation of plasma jets created by a power laser: application to laboratory astrophysics

    Plasma jets are often observed in the polar regions of Young Stellar Objects (YSO). For a better understanding of the whole processes at the origin of their formation and evolution, this research thesis aims at demonstrating the feasibility of a plasma jet generation by a power laser, and at investigating its characteristics. After a detailed description of Young Stellar Objects jets and an overview of theoretical models, the author describes some experiments performed with gas guns, pulsed machines and power lasers. He describes means of generation of a jet by laser interaction via strong shock propagation. He reports experimental work, describing the target, laser operating conditions and the determination of jet parameters: speed, temperature, density. Then, he introduces results obtained for plasma jet propagation in vacuum, describes their evolution with respect to initial conditions (target type, laser operating conditions), and identifies optimal conditions for generating a jet similar to that in astrophysical conditions. He considers their propagation in ambient medium like for YSO jets in interstellar medium. Two distinct cases are investigated: collision of two successive shocks in a gaseous medium, and propagation of a plasma jet in a gas jet

  11. An Experimental Investigation of the Role of Radiation in Laboratory Bench-Top Experiments in Thermal Physics

    Twomey, Patrick; O'Sullivan, Colm; O'Riordan, John

    2009-01-01

    A simple undergraduate experiment designed to study cooling purely by radiation and cooling by a combination of convection and radiation is described. Results indicate that the contribution from radiative cooling in normal laboratory experiments is more significant than students often realize, even in the case of forced cooling. (Contains 1…

  12. LABORATORY SETUP FOR EXPERIMENTAL INVESTIGATIONS OF INNOVATIVE ENERGY-EFFICIENT SYSTEMS’ EQUIPMENT EXAMPLES OF AGRICULTURAL ENTERPRISES OFF-LINE POWER SUPPLY ON THE BASIS OF HELIOMODULUSES

    Braginets A. V.

    2015-09-01

    Full Text Available The development of laboratory setup is connected with a necessity of designing and experimental investigation of equipment examples for innovative energy efficient system of agricultural enterprises off-line power supply on the basis of helio moduluses and is stipulated by needs of efficient heat electro supply of agricultural enterprises working in climatic regions with low and short-term solar activity. Operating regimes, matching and justification of necessary elements for the construction of the energy efficient helio system and the most efficient their arrangement are determined based on preliminary experiments. Geographical location of agricultural enterprise (the principal checkpoints should be insolation intencity and solstice angle typical for the region and social-economic development level of the region should be taken into consideration at forming demands to the constructions and abilities of heat water supply helio modules. The necessity of investigations at laboratory setup with artificial heat sources, simulating solar heat, is explained by impossibility of experiments’ carrying out in the real nature conditions, notably because of weather inconstancy and climate in tote, because of impossibility of setups exact placement on ground location, because of helio collector’s modes of operation limitation by the range of solar activity only in the investigated region etc. The list of technological parameters and helio water heating process factors, which are measured and controlled during the experiments, is built into the designing of the setup. These parameters are based on the statistical data given by meteorological stations of late years. All that will ease the designing of manufacturing helio collectors and will allow to get more precise information, oriented to the maintenance of energy efficient equipment in different zones of researched region with highest possible usage of their potential. With a glance of foresaid, we

  13. Experimental investigations on desiccant wheels

    Experimental investigations on several commercially available and newly fabricated rotors are conducted in two different laboratories to evaluate performance trends. Experimental uncertainties are analysed and the parameters determining the rotor performance are investigated. It is found that the optimal rotation speed is lower for lithium chloride or compound rotors than for silica gel rotors. Higher regeneration air temperatures lead to higher dehumidification potentials at almost equal dehumidification efficiencies, but with increasing regeneration specific heat input and enthalpy changes of the process air. The influence of the regeneration air humidity was also notable and low relative humidities increase the dehumidification potential. Finally, the measurements show that rising water content in the ambient air causes the dehumidification capacity to rise, while the dehumidification efficiency is not much affected and both specific regeneration heat input and latent heat change of the process air decrease. For desiccant cooling applications in humid climates this is a positive trend. - Highlights: ► New experimental results on a range of desiccant wheels. ► High dehumidification capacities and low enthalpy changes for process air high water content. ► Higher regeneration temperature increases capacity, but lowers energy efficiency.

  14. Solid Oxide Fuel Cell Experimental Laboratory

    Federal Laboratory Consortium — NETL’s Solid Oxide Fuel Cell Experimental Laboratory in Morgantown, WV, gives researchers access to models and simulations that predict how solid oxide fuel cells...

  15. Experimental investigation of wave boundary layer

    Sumer, B. Mutlu

    2003-01-01

    A review is presented of experimental investigation of wave boundary layer. The review is organized in six main sections. The first section describes the wave boundary layer in a real-life environment and its simulation in the laboratory in an oscillating water tunnel and in a water tank with an ...

  16. Transformative geomorphic research using laboratory experimentation

    Bennett, Sean J.; Ashmore, Peter; Neuman, Cheryl McKenna

    2015-09-01

    Laboratory experiments in geomorphology is the theme of the 46th annual Binghamton Geomorphology Symposium (BGS). While geomorphic research historically has been dominated by field-based endeavors, laboratory experimentation has emerged as an important methodological approach to study these phenomena, employed primarily to address issues related to scale and the analytical treatment of the geomorphic processes. Geomorphic laboratory experiments can result in transformative research. Several examples drawn from the fluvial and aeolian research communities are offered as testament to this statement, and these select transformative endeavors often share very similar attributes. The 46th BGS will focus on eight broad themes within laboratory experimentation, and a diverse group of scientists has been assembled to speak authoritatively on these topics, featuring several high-profile projects worldwide. This special issue of the journal Geomorphology represents a collection of the papers written in support of this symposium.

  17. The Mica Creek Experimental Watershed: An Outdoor Laboratory for the Investigation of Hydrologic Processes in a Continental/Maritime Mountainous Environment

    Link, T. E.; Gravelle, J.; Hubbart, J.; Warnsing, A.; Du, E.; Boll, J.; Brooks, E.; Cundy, T.

    2004-12-01

    Experimental catchments have proven to be extremely useful for investigations focused on fundamental hydrologic processes and on the impacts of land cover change on hydrologic regimes and water quality. Recent studies have illustrated how watershed responses to experimental treatments vary greatly between watersheds with differing physical, ecological and hydroclimatic characteristics. Meteorological and hydrological data within catchments are needed to help identify how hydrologic mechanisms may be altered by land cover alterations, and to both constrain and develop spatially-distributed physically based models. Existing instrumentation at the Mica Creek Experimental Watershed (MCEW) in northern Idaho is a fourth-order catchment that is undergoing expansion to produce a comprehensive dataset for model development and testing. The experimental catchments encompass a 28 km2 area spanning elevations from 975 to 1725 m msl. Snow processes dominate the hydrology of the catchment and climate conditions in the winter alternate between cold, dry continental and warm, moist maritime weather systems. Landcover is dominated by 80 year old second growth conifer forests, with partially cut (thinned) and clear-cut sub-catchments. Climate and precipitation data are collected at a SNOTEL site, three primary, and seven supplemental meteorological stations stratified by elevation and canopy cover. Manual snow depth measurements are recorded every 1-2 weeks during snowmelt, stratified by aspect, elevation and canopy cover. An air temperature transect spans three second-order sub-catchments to track air temperature lapse rate dynamics. Precipitation gauge arrays are installed within thinned and closed-canopy stands to track throughfall and interception loss. Nine paired and nested sub-catchments are monitored for flow, temperature, sediment, and nutrients. Hydroclimatic data are augmented by LiDAR and hyperspectral imagery for determination of canopy and topographic structure

  18. Laboratory measurements of Vp and Vs in a porosity-developed crustal rock: Experimental investigation into the effects of porosity at deep crustal pressures

    Saito, Satoshi; Ishikawa, Masahiro; Arima, Makoto; Tatsumi, Yoshiyuki

    2016-05-01

    In order to evaluate the influence of porosity on the elastic properties of crustal rocks at deep crustal pressures, we performed laboratory measurements of compressional-wave (Vp) and shear-wave (Vs) velocities in a porosity-developed gabbro sample up to 1.0 GPa at room temperature. Based on the measured Vp and Vs data, we evaluated the changes in velocities, Vp/Vs, Poisson's ratio (σ), and total porosity of the rock as a function of pressure. Compared with the 'porosity-free' intrinsic elastic values of the gabbro sample, our results suggest that the development of porosity in crustal rocks lowers their Vp, Vs, Vp/Vs, and Poisson's ratio. Deviations (ΔVp, ΔVs, ΔVp/Vs, and Δσ) of the measured values from the intrinsic values are enhanced with increasing porosity. We evaluated the ΔVp from previous experimental study on the rocks of Tanzawa plutonic complex providing constraints on interpretation of the seismic velocity profiles of the Izu-Bonin-Mariana (IBM) arc and found a large negative ΔVp (up to - 22.7%) at lower pressures. The intrinsic velocity combined with the measured velocity data at in situ pressure conditions suggest that the ranges of Vp (6.0-6.5 km/s) in the middle crust of the IBM arc reflect the presence of considerable porosity and its closure in intermediate rocks and/or the change of composition from felsic to intermediate in mid-crustal rocks.

  19. Experimental investigation of cavity flows

    Loeland, Tore

    1998-12-31

    This thesis uses LDV (Laser Doppler Velocimetry), PIV (Particle Image Velocimetry) and Laser Sheet flow Visualisation to study flow inside three different cavity configurations. For sloping cavities, the vortex structure inside the cavities is found to depend upon the flow direction past the cavity. The shape of the downstream corner is a key factor in destroying the boundary layer flow entering the cavity. The experimental results agree well with numerical simulations of the same geometrical configurations. The results of the investigations are used to find the influence of the cavity flow on the accuracy of the ultrasonic flowmeter. A method to compensate for the cavity velocities is suggested. It is found that the relative deviation caused by the cavity velocities depend linearly on the pipe flow. It appears that the flow inside the cavities should not be neglected as done in the draft for the ISO technical report on ultrasonic flowmeters. 58 refs., 147 figs., 2 tabs.

  20. Emissions from waste combustion. An application of statistical experimental design in a laboratory-scale boiler and an investigation from large-scale incineration plants

    Zhang Xiaojing

    1997-05-01

    The aim of this thesis is a study of the emissions from the combustion of household refuse. The experiments were both on a laboratory-scale boiler and on full-scale incineration plants. In the laboratory, an artificial household refuse with known composition was fed into a pilot boiler with a stationary grate. Combustion was under non-optimum conditions. Direct sampling with a Tenax adsorbent was used to measure a range of VOCs. Measurements were also made of incompletely burnt hydrocarbons, carbon monoxide, carbon dioxide, oxygen and flue gas temperature. Combustion and emission parameters were recorded continuously by a multi-point data logger. VOCs were analysed by gas chromatography and mass spectrometry (GC/MS). The full-scale tests were on seven Swedish incineration plants. The data were used to evaluate the emissions from large-scale incineration plants with various type of fuels and incinerators, and were also compared with the laboratory results. The response surface model developed from the laboratory experiments was also validated. This thesis also includes studies on the gasification of household refuse pellets, estimations of particulate and soot emissions, and a thermodynamic analysis of PAHs from combustion flue gas. For pellet gasification, experiments were performed on single, well characterised refuse pellets under carefully controlled conditions. The aim was to see if the effects of pellets were different from those of untreated household refuse. The results from both laboratory and full-scale tests showed that the main contributions to emissions from household refuse are plastics and moisture. 142 refs, 82 figs, 51 tabs

  1. Experimental investigations of ICRF effects

    The goal of the Phaedrus program is to establish the relative efficiency of helicity and momentum current drive for rf near and below omegaci and compare to theory. This paper discusses major accomplishments in the rf program; extension of operating parameters; facility improvements; and additional experimental activities

  2. Experimental investigation of plasmofluidic waveguides

    Ku, Bonwoo; Kwon, Min-Suk, E-mail: mskwon@unist.ac.kr [School of Electrical and Computer Engineering, UNIST, 50 UNIST-gil, Eonyang-eup, Ulju-gun, Ulsan 689-798 (Korea, Republic of); Shin, Jin-Soo [Department of Electrical Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

    2015-11-16

    Plasmofluidic waveguides are based on guiding light which is strongly confined in fluid with the assistance of a surface plasmon polariton. To realize plasmofluidic waveguides, metal-insulator-silicon-insulator-metal (MISIM) waveguides, which are hybrid plasmonic waveguides fabricated using standard complementary metal-oxide-semiconductor technology, are employed. The insulator of the MISIM waveguide is removed to form 30-nm-wide channels, and they are filled with fluid. The plasmofluidic waveguide has a subwavelength-scale mode area since its mode is strongly confined in the fluid. The waveguides are experimentally characterized for different fluids. When the refractive index of the fluid is 1.440, the plasmofluidic waveguide with 190-nm-wide silicon has propagation loss of 0.46 dB/μm; the coupling loss between it and an ordinary silicon photonic waveguide is 1.79 dB. The propagation and coupling losses may be reduced if a few fabrication-induced imperfections are removed. The plasmofluidic waveguide may pave the way to a dynamically phase-tunable ultracompact device.

  3. Quantifying the accuracy of laboratory SIP experimental set ups

    Ntarlagiannis, D.; Slater, L. D.

    2014-12-01

    Over the last decade the spectral induced polarization (SIP) method has reemerged as a promising method for subsurface investigations. The sensitivity of SIP to bulk and interfacial physicochemical properties permits a wider range of hydrogeophysical and environmental applications, including monitoring of subsurface biogeochemical transformations. Improvements in instrumentation and experimental designs, along with faster acquisition capabilities and easy access to processing routines are encouraging novel applications of the method, and support quantitative interpretation of the data acquired. Motivated by recent research that focus on small scale changes, over large frequency ranges, we performed a series of experiments to identify the accuracy of common laboratory SIP experimental set ups. We performed measurements on resistor - capacitor (RC) networks, to identify the instrumentation accuracy, and also on standard laboratory columns filled with materials of known SIP response, primarily on well characterized fluids of different conductivity. Early results show small errors in the low frequency range, attributed to electrode polarization; in higher frequencies, typically above 1000 Hz, the errors may become significant limiting the meaningful interpretation of small phase angles at these frequencies. The data will be compared with published data using comparable experimental set ups, and could be used to set realistic expectations on future SIP experiments and applications. With this work we aim at developing a best practices document that can aid the SIP user in collecting meaningful and repeatable results.

  4. Investigating Coccolithophorid Biology in the Sedimentary Laboratory

    McClelland, H. L. O.; Barbarin, N.; Beaufort, L.; Hermoso, M.; Rickaby, R. E. M.

    2014-12-01

    Coccolithophores are the ocean's dominant calcifying phytoplankton; they play an important, but poorly understood, role in long-term biogeochemical climatic feedbacks. Calcite producing marine organisms are likely to calcify less in a future world where higher carbon dioxide concentrations will lead to ocean acidification (OA), but coccolithophores may be the exception. In coccolithophores calcification occurs in an intracellular vesicle, where the site of calcite precipitation is buffered from the external environment and is subject to a uniquely high degree of biological control. Culture manipulation experiments mimicking the effects of OA in the laboratory have yielded empirical evidence for phenotypic plasticity, competition and evolutionary adaptation in asexual populations. However, the extent to which these results are representative of natural populations, and of the response over timescales of greater than a few hundred generations, is unclear. Here we describe a new sediment-based proxy for the PIC:POC (particulate inorganic to particulate organic carbon ratio) of coccolithophore biomass, which is equivalent to the fractional energy contribution to calcification at constant pH, and a biologically meaningful measure of the organism's tendency to calcify. Employing the geological record as a laboratory, we apply this proxy to sedimentary material from the southern Pacific Ocean to investigate the integrated response of real ancient coccolithophore populations to environmental change over many thousands of years. Our results provide a new perspective on phenotypic change in real populations of coccolithophorid algae over long timescales.

  5. Experimental Results in DIS from Jefferson Laboratory

    Sebastian Kuhn

    2009-10-01

    We are summarizing the experimental program of Jefferson Lab (Thomas Jefferson National Accelerator Facility in Newport News, VA) in deep inelastic electron scattering. We show recent results and discuss future plans for both the present 6 GeV era and the 12 GeV energy-upgraded facility.

  6. Laboratory Investigation of the Airglow Bands

    Drouin, Brian; Yu, Shanshan; Crawford, Timothy J.; Miller, Charles E.; Yee, Jeng-Hwa

    2013-06-01

    We report the first high spectral resolution laboratory measurements of oxygen A-band night glow simulated using a static discharge cell. Our static discharge system reproduces the conditions of the mesospheric oxygen night glow - suggesting O(^1D) + O_2 as the primary source of the emission. Additionally, use of the static cell has enabled us to collect spectra for rare molecular oxygen isotopologues using isotopically enriched samples. The (0,0), (0,1), and (1,1) b-Xvibrational bands were observed with a Bruker 125 HR for all six isotopologues. The (1,2) and (2,2) bands were observed also for the main isotopologue. The frequencies of the observed (0,1) transitions resolved discrepancies in Raman data for (16-17, 17-17, and 17-18), enabling us to improve the vibrational parameterization of the ground electronic state in the global fit of Yu et al. Rotationally resolved intensities were determined for the (0,0), (0,1) and (1,1) bands. The experimental band intensity ratios I(0,0)/I(0,1) = 13.6 and I(0,0)/I(1,1) = 60 are in excellent agreement with the recent mesospheric remote sensing data. S. Yu, C.E. Miller, B.J. Drouin, H.S.P. Müller, J. Chem. Phys. 136, 024304, 2012

  7. Pressure laboratories for parameter controlled experimentation of deep sea environments

    Steffen, H.; Holscher, B.; Gust, G.; Thomsen, L.

    2003-04-01

    The in-situ examination of deep sea environments poses many challenges and cannot always be optimised which places the researcher at a disadvantage upon encountering high costs, few possibilities of controlling the naturally given parameters such as temperature, pressure or hydrodynamic conditions, and weather conditions while at sea. To overcome these limitations, pressure laboratories are emerging tools for biological, chemical and geological studies. The Department of Ocean Engineering 1 of the Technical University Hamburg-Harburg has been developing different types of pressure laboratories to meet the needs of the natural sciences. Three types of experimental settings were identified for examination and manipulation: experiments with artificial samples, natural samples that have been decompressed during recovery and re-pressurised, and, finally, natural samples in their original, undamaged state. We concentrate on the latter type of settings. For the laboratory simulations, different transfer units are needed for the decompression-free transfer from field site to laboratory, depending on sample type consisting of either fluids, solid-liquid suspensions including small particles and living organisms, or sediment cores. The pressure labs are thus linked to the in-situ site through special sample and transfer units which collect the undisturbed deep sea samples. As a result, laboratory investigation, after sample transfer, is very similar to in-situ analysis, but with the advantage of perfect control of the sample's environment and condition including the hydrodynamics at the sea bed. Two pressure laboratories that accomplish the given investigation tasks with different types of samples for depths down to 5500 m will be presented together with the related technology for sample acquisition. The latest system will be mobile, fully modular, and container based. Examples of experiments, some completed and some in progress, will be shown: Biological experiments include

  8. Epistemological Dizziness in the Psychology Laboratory: Lively Subjects, Anxious Experimenters, and Experimental Relations, 1950-1970.

    Morawski, Jill

    2015-09-01

    Since the demise of introspective techniques in the early twentieth century, experimental psychology has largely assumed an administrative arrangement between experimenters and subjects wherein subjects respond to experimenters' instructions and experimenters meticulously constrain that relationship through experimental controls. During the postwar era this standard arrangement came to be questioned, initiating reflections that resonated with Cold War anxieties about the nature of the subjects and the experimenters alike. Albeit relatively short lived, these interrogations of laboratory relationships gave rise to unconventional testimonies and critiques of experimental method and epistemology. Researchers voiced serious concerns about the honesty and normality of subjects, the politics of the laboratory, and their own experimental conduct. Their reflective commentaries record the intimacy of subject and experimenter relations and the plentiful cultural materials that constituted the experimental situation, revealing the permeable boundaries between laboratory and everyday life. PMID:26685518

  9. Experimental investigation of quadrupole virtual photon spectrum

    To test experimentally the quadrupole virtual photon spectrum calculation, the (e,α) excitation function of an isolated 2+ level at 20.14 MeV in 24Mg was measured. The most recent calculations in DWBA, including nuclear size effects, are compared to this experimental curve. The differential cross section d2σ/dΩdE was measured 480, 900, 1320 in the laboratory system, for total electron energies of 20.0, 20.8, 21.5, 24.0, 26.0, 28.0, 30.0, 32.0, 36.0, and 40.0 MeV. The reduced matrix element B(E2) of the 20,14 MeV level is extracted as a secondary product of this work. (author)

  10. Preliminary rock mechanics laboratory: Investigation plan

    This document presents the rationale for rock mechanics laboratory testing (including the supporting analysis and numerical modeling) planned for the site characterization of a nuclear waste repository in salt. This plan first identifies what information is required for regulatory and design purposes, and then presents the rationale for the testing that satisfies the required information needs. A preliminary estimate of the minimum sampling requirements for rock laboratory testing during site characterization is also presented. Periodic revision of this document is planned

  11. Experimental investigation of thermal barriers. Final report

    During this contract period, we completed the following small scale laboratory experiments: (a) plasma confinement by picket fence cusp magnetic fields. (b) Electrostatic plugging of picket fence cusps. (c) Investigations of sheath phenomena including: characteristics of probe sheaths, secondary electrons in a plasma-wall sheath, and end wall characteristics in TMX. (d) Suppression of secondary electron emission by permanent magnet produced multidipole magnetic field. (e) Electron thermal insulation by double layers and multiple double layers. Many of these investigations have already had important consequences in the development of improvement for neutral beam sources

  12. The European Network of Analytical and Experimental Laboratories for Geosciences

    Freda, Carmela; Funiciello, Francesca; Meredith, Phil; Sagnotti, Leonardo; Scarlato, Piergiorgio; Troll, Valentin R.; Willingshofer, Ernst

    2013-04-01

    Integrating Earth Sciences infrastructures in Europe is the mission of the European Plate Observing System (EPOS).The integration of European analytical, experimental, and analogue laboratories plays a key role in this context and is the task of the EPOS Working Group 6 (WG6). Despite the presence in Europe of high performance infrastructures dedicated to geosciences, there is still limited collaboration in sharing facilities and best practices. The EPOS WG6 aims to overcome this limitation by pushing towards national and trans-national coordination, efficient use of current laboratory infrastructures, and future aggregation of facilities not yet included. This will be attained through the creation of common access and interoperability policies to foster and simplify personnel mobility. The EPOS ambition is to orchestrate European laboratory infrastructures with diverse, complementary tasks and competences into a single, but geographically distributed, infrastructure for rock physics, palaeomagnetism, analytical and experimental petrology and volcanology, and tectonic modeling. The WG6 is presently organizing its thematic core services within the EPOS distributed research infrastructure with the goal of joining the other EPOS communities (geologists, seismologists, volcanologists, etc...) and stakeholders (engineers, risk managers and other geosciences investigators) to: 1) develop tools and services to enhance visitor programs that will mutually benefit visitors and hosts (transnational access); 2) improve support and training activities to make facilities equally accessible to students, young researchers, and experienced users (training and dissemination); 3) collaborate in sharing technological and scientific know-how (transfer of knowledge); 4) optimize interoperability of distributed instrumentation by standardizing data collection, archive, and quality control standards (data preservation and interoperability); 5) implement a unified e-Infrastructure for data

  13. Mars Science Laboratory Mission and Science Investigation

    Grotzinger, John P.; Crisp, J.; Vasavada, A R; Anderson, R.C.; Baker, C J; Barry, R.; Ferdowski, B.; Gilbert, J. B.; Golombek, M.; Jandura, L.; Maki, J; Simmonds, J. J.; Welch, R. V.

    2012-01-01

    Scheduled to land in August of 2012, the Mars Science Laboratory (MSL) Mission was initiated to explore the habitability of Mars. This includes both modern environments as well as ancient environments recorded by the stratigraphic rock record preserved at the Gale crater landing site. The Curiosity rover has a designed lifetime of at least one Mars year (∼23 months), and drive capability of at least 20 km. Curiosity’s science payload was specifically assembled to assess habitability and inclu...

  14. The Locust Jump: An Integrated Laboratory Investigation

    Scott, Jon

    2005-01-01

    The locust is well known for its ability to jump large distances to avoid predation. This class sets out a series of investigations into the mechanisms underlying the jump enabling students to bring together information from biomechanics, muscle physiology, and anatomy. The nature of the investigation allows it to be undertaken at a number of…

  15. Experimental Investigation of a Rectangular Airlift Pump

    I. I. Esen

    2010-01-01

    Hydraulic performance of an airlift pump having a rectangular cross-section 20 mm × 80 mm was investigated through an experimental program. The pump was operated at six different submergence ratios and the liquid flow rate was measured at various flowrates of air injected. The effectiveness of the pump, defined as the ratio of the mass of liquid pumped to the mass of air injected, was determined as a function of the mass of air injected for different submergence ratios. Results obtained were ...

  16. A Novel Experimental Technique to Simulate Pillar Burst in Laboratory

    He, M. C.; Zhao, F.; Cai, M.; Du, S.

    2015-09-01

    Pillar burst is one type of rockburst that occurs in underground mines. Simulating the stress change and obtaining insight into the pillar burst phenomenon under laboratory conditions are essential for studying the rock behavior during pillar burst in situ. To study the failure mechanism, a novel experimental technique was proposed and a series of tests were conducted on some granite specimens using a true-triaxial strainburst test system. Acoustic emission (AE) sensors were used to monitor the rock fracturing process. The damage evolution process was investigated using techniques such as macro and micro fracture characteristics observation, AE energy evolution, and b value analysis and fractal dimension analysis of cracks on fragments. The obtained results indicate that stepped loading and unloading simulated the pillar burst phenomenon well. Four deformation stages are divided as initial stress state, unloading step I, unloading step II, and final burst. It is observed that AE energy has a sharp increase at the initial stress state, accumulates slowly at unloading steps I and II, and increases dramatically at peak stress. Meanwhile, the mean b values fluctuate around 3.50 for the first three deformation stages and then decrease to 2.86 at the final stage, indicating the generation of a large amount of macro fractures. Before the test, the fractal dimension values are discrete and mainly vary between 1.10 and 1.25, whereas after failure the values concentrate around 1.25-1.35.

  17. Preparation of bentonites for laboratory investigations

    A project study on behalf of Nagra for high radioactive waste disposal in deep geological formations as well as literature studies have shown that bentonite could be a suitable filling and sealing material. The Institute for Foundation and Soil Mechanics of the Swiss Institute of Technology has been given a contract by Nagra to investigate different bentonites. The investigations concentrate on the Na-bentonite MX-80 from Wyoming, which is foreseen by the Swedes, and on the geographically more favorable Ca-bentonite Montigel from Bavaria. Montigel powder and granulate, which show certain manufacturing advantages, were investigated. The quality of the bentonites was examined especially to ascertain whether the bentonites were homogeneous with respect to composition and properties. Montmorillonite, carbonate, oxidizing substances and exchangeable ions were quality content criteria for bentonite. The investigations showed that these bentonites are typical Na- and Ca-bentonites. A representative sample of 500 kg weight (250 kg for Montigel K) was largely homogeneous. The samples were analysed by x-rays and thermoanalysis. Additionally grain size, carbonate content, methylene blue value, yield point, exchange capacity and exchangeable ions were determined. 5 refs., 2 figs., 2 tabs

  18. Experimental Investigation of Shock Wave Surfing

    Parziale, N J; Hornung, H G; Shepherd, J E

    2010-01-01

    Shock wave surfing is investigated experimentally in GALCIT's Mach 4.0 Ludwieg Tube. Shock wave surfing occurs when a secondary free-body follows the bow shock formed by a primary free-body; an example of shock wave surfing occurs during meteorite breakup. The free-bodies in the current investigation are nylon spheres. During each run in the Ludwieg tube a high speed camera is used to capture a series of schlieren images; edge tracking software is used to measure the position of each sphere. Velocity and acceleration are had from processing the position data. The radius ratio and initial orientation of the two spheres are varied in the test matrix. The variation of sphere radius ratio and initial angle between the centers of gravity are shown to have a significant effect on the dynamics of the system.

  19. Experimental investigation of magnetically confined plasma loops

    Tenfelde, Jan

    2012-12-11

    Arch-shaped magnetic flux tubes generated in a pulsed-power plasma experiment were investigated with a variety of diagnostics concerning their expansion properties. Specifically, the expansion velocity was of interest, which is observed as constant for a wide range of experimental parameters. An MHD transport mechanism is investigated as possible cause of a uniform arch cross section: Axial transport of poloidal magnetic flux along the plasma may cause a pinch force leading to a uniform diameter along the arch. Despite numerous experimental findings at a very similar experimental setup, no indication for the relevance of this process could be found. Instead, magnetic probe data showed that the plasma current in the apex region is constant. A constant expansion velocity was observed for considerably different experimental conditions. This included different plasma source designs with fundamentally different toroidal magnetic field topology and variation of the working gas, which lead to plasma densities lower by an order of magnitude. Inside the current channel of the arch, Alfven velocities were estimated. To this end, plasma density profiles obtained from interferometry were inverted to obtain local densities, which were in turn verified by means of Stark broadening of hydrogen Balmer lines. Furthermore, measurements of multiple components of the magnetic field of the plasma arch were performed. An estimate for the conductivity was obtained from Spitzer's formula for fully ionized plasma using electron temperatures obtained from elementary optical emission spectroscopy. From the presented data of ccd imaging, magnetic field probes, and to lesser extent, interferometry, the underlying assumption of residual plasma (and considerable plasma currents through it) below the actual arch structure is very plausible. Rough estimates of the electric field strength along the arch and results of the magnetic field measurements showed, that the detected expansion

  20. Experimental investigation of magnetically confined plasma loops

    Arch-shaped magnetic flux tubes generated in a pulsed-power plasma experiment were investigated with a variety of diagnostics concerning their expansion properties. Specifically, the expansion velocity was of interest, which is observed as constant for a wide range of experimental parameters. An MHD transport mechanism is investigated as possible cause of a uniform arch cross section: Axial transport of poloidal magnetic flux along the plasma may cause a pinch force leading to a uniform diameter along the arch. Despite numerous experimental findings at a very similar experimental setup, no indication for the relevance of this process could be found. Instead, magnetic probe data showed that the plasma current in the apex region is constant. A constant expansion velocity was observed for considerably different experimental conditions. This included different plasma source designs with fundamentally different toroidal magnetic field topology and variation of the working gas, which lead to plasma densities lower by an order of magnitude. Inside the current channel of the arch, Alfven velocities were estimated. To this end, plasma density profiles obtained from interferometry were inverted to obtain local densities, which were in turn verified by means of Stark broadening of hydrogen Balmer lines. Furthermore, measurements of multiple components of the magnetic field of the plasma arch were performed. An estimate for the conductivity was obtained from Spitzer's formula for fully ionized plasma using electron temperatures obtained from elementary optical emission spectroscopy. From the presented data of ccd imaging, magnetic field probes, and to lesser extent, interferometry, the underlying assumption of residual plasma (and considerable plasma currents through it) below the actual arch structure is very plausible. Rough estimates of the electric field strength along the arch and results of the magnetic field measurements showed, that the detected expansion

  1. Experimental and theoretical investigations of falling film evaporation

    Pehlivan, Hüseyin; Özdemir, Mustafa

    2012-06-01

    In this study, a mathematical model was developed for falling film evaporation in vacuum using heat transfer relations. An experimental device was designed. experimental set-up which was used was equipped with a triangular weir distribution device and it had the ability to record data up to 3 m. Experiments were performed in a single-effect process with sucrose-water solution varying from 3 to 20% concentration rate of sucrose and we used a vertical tube evaporator with the dimensions of laboratory scale. The model that was developed considers convection, shear stress, viscosity and conjugate heat transfer while most of the previous works ignored these factors. The main factors influencing the heat transfer mechanism performance of the unit were investigated and analyzed. We concluded that the experimental studies are verified by the developed model. Furthermore, it was also concluded that, the heat transfer is affected by the mass flow rate, sucrose concentration rate in solution, film thickness and pressure.

  2. Open-ended versus guided laboratory activities: Impact on students' beliefs about experimental physics

    Wilcox, Bethany R

    2016-01-01

    Improving students' understanding of the nature of experimental physics is often an explicit or implicit goal of undergraduate laboratory physics courses. However, lab activities in traditional lab courses are typically characterized by highly structured, guided labs that often do not require or encourage students to engage authentically in the process of experimental physics. Alternatively, open-ended laboratory activities can provide a more authentic learning environment by, for example, allowing students to exercise greater autonomy in what and how physical phenomena are investigated. Engaging in authentic practices may be a critical part of improving students' beliefs around the nature of experimental physics. Here, we investigate the impact of open-ended activities in undergraduate lab courses on students' epistemologies and expectations about the nature of experimental physics, as well as their confidence and affect, as measured by the Colorado Learning Attitudes about Science Survey for Experimental Ph...

  3. Failure investigations in the nuclear materials laboratory

    A report is given of damage to hydrostatic floating seals (with a single-stage pressure drop of 155 bar) from pressurized water reactors. The seals were manufactured from the steel X 22 CrNi 17 and plasmacoated with a layer of Cr2O3. The types of damage occurring (green discoloration and hump formation) are discussed in terms of their mechanistic causes. A further investigation involved metallographic examination with optical and scanning electron microscopes of seven specimens from thin-walled piping made of the finegrained, structural steel 17 MnMoV 6,4 in which cracking had occurred in weld regions, in particular, crack growth and the form of cracking at the weld root were investigated. (orig.)

  4. Experimental investigations of MFCI in Russia

    This report contains a review of the experimental investigations of MFCI which are carried out as applied to the safety problems of LMFBR, mainly in IPPE. Until the present time these investigations have been performed in out of pile conditions, using different substances for molten fuel simulation. A brief description of the experimental installations and results obtained in the course of experimental program realization is given. In particular the results are presented on the study of MFCI phenomenology with regards to the influence on the interaction energy release of such factors as: type of molten fuel-coolant contact, temperature conditions, ratio of interacted masses, scale factor. Simulation experiments have been effectuated using the following pairs of interaction media: low-melting metals (Lead, Tin, Bismuth, Aluminium)/water; molten Titan and Stainless steel/water; molten Titan and Stainless steel/sodium, eutectic alloy potassium-sodium; alumina/sodium; thermite mixture (Zr + Fe2O3)/water, sodium. The experiments were carried out mainly with the melts masses below 1 kg, except for some series of the experiments on molten Lead-water interaction, where the melt masses as big as 40 kg were used. Initial temperatures of low-melting metals have not exceeded 800 deg. C, while for the Stainless steel, Titan melts and alumina they were equal to 2200 deg. and 2500 deg. C respectively. The temperature of the melt, obtained by combustion of the thermite mixture Zr + Fe2O3, was about 3000 deg. C. The first part of the MFCI investigation program has been completed for the present time. A set of the data on the dynamical characteristics of interactions (time delays, amplitudes and shape of interaction pressure pulses, duration of interaction stage) and conversion coefficients of melt thermal energy into mechanical one was obtained. Analysis of these results has shown an essentially milder interaction energetics in the case of alkali metals coolants as compared with

  5. Storage of high-level wastes, investigations in underground laboratories

    This article reviews the different collaborations made by ANDRA (national agency for the management of radioactive wastes) in the fields of underground radioactive waste storage. ANDRA has taken part in various experimental research programs performed in laboratories such as Mol in Belgium, Aspo in Sweden, Pinawa in Canada and Grimsel in Switzerland. This article details the experiments led at Mol since 1984. ANDRA is commissioned by the 30.12.91 decree to study the possibility of storage in deep geological layers. A thorough knowledge of the matter requires the building of underground laboratories in order to test and validate technological choices on a real scale. 6 themes will have to be investigated: 1) the capacity to seal up the storage facility after its use in order to assure the protection of man and environment, 2) the effects of geological perturbations on the confining properties of the site, 3) the confining ability of the Callovian-Oxfordian geological formation, 4) the transfer of radionuclides from the geological formation to the biosphere, 5) the constructing possibility of an underground storage facility, and 6) the possibility of retrieving the stored packages. (A.C.)

  6. Mars Science Laboratory Mission and Science Investigation

    Grotzinger, John P.; Crisp, Joy; Vasavada, Ashwin R.; Anderson, Robert C.; Baker, Charles J.; Barry, Robert; Blake, David F.; Conrad, Pamela; Edgett, Kenneth S.; Ferdowski, Bobak; Gellert, Ralf; Gilbert, John B.; Golombek, Matt; Gómez-Elvira, Javier; Hassler, Donald M.; Jandura, Louise; Litvak, Maxim; Mahaffy, Paul; Maki, Justin; Meyer, Michael; Malin, Michael C.; Mitrofanov, Igor; Simmonds, John J.; Vaniman, David; Welch, Richard V.; Wiens, Roger C.

    2012-09-01

    Scheduled to land in August of 2012, the Mars Science Laboratory (MSL) Mission was initiated to explore the habitability of Mars. This includes both modern environments as well as ancient environments recorded by the stratigraphic rock record preserved at the Gale crater landing site. The Curiosity rover has a designed lifetime of at least one Mars year (˜23 months), and drive capability of at least 20 km. Curiosity's science payload was specifically assembled to assess habitability and includes a gas chromatograph-mass spectrometer and gas analyzer that will search for organic carbon in rocks, regolith fines, and the atmosphere (SAM instrument); an x-ray diffractometer that will determine mineralogical diversity (CheMin instrument); focusable cameras that can image landscapes and rock/regolith textures in natural color (MAHLI, MARDI, and Mastcam instruments); an alpha-particle x-ray spectrometer for in situ determination of rock and soil chemistry (APXS instrument); a laser-induced breakdown spectrometer to remotely sense the chemical composition of rocks and minerals (ChemCam instrument); an active neutron spectrometer designed to search for water in rocks/regolith (DAN instrument); a weather station to measure modern-day environmental variables (REMS instrument); and a sensor designed for continuous monitoring of background solar and cosmic radiation (RAD instrument). The various payload elements will work together to detect and study potential sampling targets with remote and in situ measurements; to acquire samples of rock, soil, and atmosphere and analyze them in onboard analytical instruments; and to observe the environment around the rover. The 155-km diameter Gale crater was chosen as Curiosity's field site based on several attributes: an interior mountain of ancient flat-lying strata extending almost 5 km above the elevation of the landing site; the lower few hundred meters of the mountain show a progression with relative age from clay-bearing to sulfate

  7. Experimental investigation of passive pool mixing

    After the initial blow-down phase of a hypothetical design basis accident or severe accident in the General Electric Simplified Boiling Water Reactor (SBWR), heat is added to the suppression pool by gas-vapor flow through the isolation condenser (IC) and passive containment cooler (PCC) vent lines. The exit of the vent lines is fairly shallow (on the order of 0.75 meters) in order to enhance IC/PCC operation. The surface temperature of a pool increases when heat is injected. The magnitude of increase depends on the amount of the pool involved in heat absorption and thermal gradients in the absorbing region. Thermal stratification occurs because a rising plume carries the energy of the vented gas-vapor to the pool surface and, as a result, only the region of the pool above the injection point is involved in heat absorption. This experimental investigation demonstrated the feasibility of using the IC/PCC vent flow to drive pool mixing. A passive mixer was designed and constructed on the basis of buoyancy and momentum utilization. The mixer was sized to represent one in a system of several mixers which could be implemented in the SBWR. The experimental results show that the potential exists to involve a significant amount of the suppression pool in heat absorption using a passive mixer

  8. Experimental investigation of the role of ions in aerosol nucleation

    Enghoff, Martin Andreas Bødker

    nucleation theory. Several ideas have been put forward to solve this nucleation problem, e.g. Ion-Induced Nucleation (Raes & Janssens 1985) and Ternary Nucleation (Kulmala et al. 2000). Experimental investigations exploring the role of ions in particle production are scarce, and often at conditions far...... energetic cosmic rays can promote the production of cloud condensation nuclei at low altitudes constitutes a link between cosmic rays and Earth's climate and there is thus a need to corroborate the results in a different experiment The present results are obtained in the same laboratory, but using a new...

  9. Propane hydrate nucleation: Experimental investigation and correlation

    Jensen, Lars; Thomsen, Kaj; von Solms, Nicolas

    2008-01-01

    In this work the nucleation kinetics of propane gas hydrate has been investigated experimentally using a stirred batch reactor. The experiments have been performed isothermally recording the pressure as a function of time. Experiments were conducted at different stirring rates, but in the same...... supersaturation region. The experiments showed that the gas dissolution rate rather than the induction time of propane hydrate is influenced by a change in agitation. This was especially valid at high stirring rates when the water surface was severely disturbed.Addition of polyvinylpyrrolidone (PVP...... the presence of additives. In most cases reasonable agreement between the data and the model could be obtained. The results revealed that especially the effective surface energy between propane hydrate and water is likely to change when the stirring rate varies from very high to low. The prolongation...

  10. Comparison of Laboratory Experimental Data to XBeach Numerical Model Output

    Demirci, Ebru; Baykal, Cuneyt; Guler, Isikhan; Sogut, Erdinc

    2016-04-01

    generating data sets for testing and validation of sediment transport relationships for sand transport in the presence of waves and currents. In these series, there is no structure in the basin. The second and third series of experiments were designed to generate data sets for development of tombolos in the lee of detached 4m-long rubble mound breakwater that is 4 m from the initial shoreline. The fourth series of experiments are conducted to investigate tombolo development in the lee of a 4m-long T-head groin with the head section in the same location of the second and the third tests. The fifth series of experiments are used to investigate tombolo development in the lee of a 3-m-long rubble-mound breakwater positioned 1.5 m offshore of the initial shoreline. In this study, the data collected from the above mentioned five experiments are used to compare the results of the experimental data with XBeach numerical model results, both for the "no-structure" and "with-structure" cases regarding to sediment transport relationships in the presence of only waves and currents as well as the shoreline changes together with the detached breakwater and the T-groin. The main purpose is to investigate the similarities and differences between the laboratory experimental data behavior with XBeach numerical model outputs for these five cases. References: Baykal, C., Sogut, E., Ergin, A., Guler, I., Ozyurt, G.T., Guler, G., and Dogan, G.G. (2015). Modelling Long Term Morphological Changes with XBeach: Case Study of Kızılırmak River Mouth, Turkey, European Geosciences Union, General Assembly 2015, Vienna, Austria, 12-17 April 2015. Gravens, M.B. and Wang, P. (2007). "Data report: Laboratory testing of longshore sand transport by waves and currents; morphology change behind headland structures." Technical Report, ERDC/CHL TR-07-8, Coastal and Hydraulics Laboratory, US Army Engineer Research and Development Center, Vicksburg, MS. Roelvink, D., Reniers, A., van Dongeren, A., van Thiel de

  11. Modelling and laboratory investigation of microbial enhanced oil recovery

    Desouky, S.M. [King Saud University, College of Engineering, Riyadh (Saudi Arabia); Abdel-Daim, M.M.; Sayyouh, M.H.; Dahab, A.S. [Cairo University, College of Engineering and Petroleum Engineering Department, Giza (Egypt)

    1996-08-15

    A one-dimensional model was developed to simulate the process of enhanced oil recovery by microorganisms. The model involves five components (oil, water, bacteria, nutrient and metabolites), with adsorption, diffusion, chemotaxis, growth and decay of bacteria, nutrient consumption, permeability damage and porosity reduction effects. Experiments were conducted to identify the parameters affecting the transport and growth of three bacterial strains: Streptococcus, Staphylococcus and Bacillus in porous media. Several correlations were developed from the experimental laboratory data and were used in the simulator. Comparison between the experimental and simulated results emphasized the validity of the developed simulator and determined its degree of accuracy (average absolute relative error=8.323%). The simulator was used to investigate the effects of indigenous bacteria, slug size, incubation time, residual oil saturation, absolute permeability, and injection flow rate on oil recovery. Results show that more oil can be recovered by using Streptococcus with molasses as a medium. Oil recovery is sensitive to variation in concentration of injected indigenous bacteria, size of bacterial culture slug, incubation time and residual oil saturation. The change of absolute permeability, or injection flow rate, has no effect on oil recovery efficiency by bacteria

  12. Investigating Student Perceptions of the Chemistry Laboratory and Their Approaches to Learning in the Laboratory

    Berger, Spencer Granett

    laboratory procedures. In order to test the effects of the intervention, an experimental group (N=87) completed these supplementary questions during two laboratory experiments while a control group (N=84) performed the same experiments without these additional questions. The effects of the intervention on laboratory exam performance were measured. Students in the experimental group had a higher average on the laboratory exam than students in the control group.

  13. [LABORATORY AND EXPERIMENTAL STUDY OF THE COMPLEX PROBIOTIC PREPARATION "BIFILACT-BILS" IN CAPSULATED FORM].

    Neschislyaev, V A; Stolbova, M G; Mokin, P A; Orlova, E V; Ershov, A E

    2016-01-01

    The composition and technology of complex probiotic in hard gelatin capsules was developed in Perm Branch "Biomed" of "Microgen" State Company. The preparation contains three production strains: Lactobacillus plantarum 8P-A3, L. acidophilus K3W24 and Bifidobacterium bifidum 1. Laboratory and experimental (preclinical) study of the probiotic included investigation of the antagonistic activity, "acute" and "chronic" toxicity, the effect of the preparation on histology and hematology of laboratory animals. The result of these studies suggested of the probiotic had high inhibitory activity against pathogenic microflora when compared with probiotic monopreparations and had no toxic effects on laboratory animals. PMID:27301138

  14. An Investigative, Cooperative Learning Approach to the General Microbiology Laboratory

    Seifert, Kyle; Fenster, Amy; Dilts, Judith A.; Temple, Louise

    2009-01-01

    Investigative- and cooperative-based learning strategies have been used effectively in a variety of classrooms to enhance student learning and engagement. In the General Microbiology laboratory for juniors and seniors at James Madison University, these strategies were combined to make a semester-long, investigative, cooperative learning experience…

  15. An Experimental Investigation of Cognitive Defusion

    Pilecki, Brian C.; McKay, Dean

    2012-01-01

    The current study compared cognitive defusion with other strategies in reducing the impact of experimentally induced negative emotional states. Sixty-seven undergraduates were assigned to one of three conditions (cognitive defusion, thought suppression, or control) and instructed in standardized approaches relevant to each condition before viewing…

  16. Structural failures and experimental investigations of lightweightstructures

    Drdácký, Miloš

    Varšava: Wydawnictwo naukowe, 2002 - (Obrebski, J.), s. 613-622 ISBN 83-908867-6-6. [Lightweight structures in civil engineering. Varšava (PL), 24.06.2002-28.06.2002] R&D Projects: GA MK PK99P04OPP006 Keywords : structural failures, forensic engineering, experimental mechanics Subject RIV: JN - Civil Engineering

  17. Experimental investigation of gas aerostatic bearings

    Steinbauer, P.; Šika, Z.; Kozánek, Jan; Šimek, J.

    2008-01-01

    Roč. 3, - (2008), s. 769-776. ISSN 1335-2393 R&D Projects: GA ČR GA101/06/1787 Institutional research plan: CEZ:AV0Z20760514 Keywords : aerostatic bearing * experimental identification * measurement Subject RIV: BI - Acoustics

  18. Experimental Investigation on Hydrodynamic Behavior of the Geometric Spar Platform

    ZHANG Fan; YANG Jian-min; LI Run-pei; CHEN Gang

    2006-01-01

    In recent years, attention has been focused on the spar platform for gas and oil exploitation in deep water. With the development of offshore technology, many new spar concepts have been put forward and fully studied. This paper presents the results of an experimental investigation on the hydrodynamic behavior of a new spar concept from Novellent Offshore LLC, USA, which is called Geometric Spar (G-spar). A new type of buoyancy can concept from the same company, viz. Integrated Buoyancy Can (IBC), is researched in the meantime. The G-spar and IBC models with a 1:70 scale are tested in the State Key Laboratory of Ocean Engineering at Shanghai Jiao Tong University for the global performance of the spar hull, in which the second-order wave drift force is involved, as well as the effect of heave plates on the motion characteristics and mooring force of the G-spar platform.

  19. A Vodcasted, Cross-Disciplinary, Behavioral Neuroscience Laboratory Exercise Investigating the Effects of Methamphetamine on Aggression

    Shanks, Ryan A.; Southard, E. Megan; Tarnowski, Laura; Bruster, Matthew; Wingate, Stacia W.; Dalman, Nancy; Lloyd, Steven A.

    2011-01-01

    This article describes a laboratory experience utilizing videos to engage students in hypothesis-driven experimentation in behavioral neuroscience. It provides students with an opportunity to investigate the effects of chronic methamphetamine exposure on aggression in adult mice using a resident-intruder paradigm. Instructors and students only…

  20. Experimental Investigation of Thermal Conductivity through Nanofluids

    Abid, Muhammad

    2012-01-01

    ABSTRACT: The method used in this experimental work is the Temperature Oscillation Technique (TOT). Thermal conductivity measurement through Temperature Oscillation Technique is to fill the cylinder with the nanofluids, and apply the temperature oscillations at both ends of the cylinder. It measures the phase and amplitude of the temperature oscillation in the center and at both ends of the cylinder. Thermal diffusivity is calculated from the phase and amplitude values. Furthermore, thermal c...

  1. Experimental investigation of a control synthetic jet

    Němcová, L.; Kordík, Jozef; Trávníček, Zdeněk; Kopecký, V.

    Vol. 1. Liberec : TU Liberec, 2011 - (Vít, T.; Dančová, P.; Novotný, P.), s. 315-322 ISBN 978-80-7372-784-0. [Experimental Fluid Mechanics 2011. Jičín (CZ), 22.11.2011-25.11.2011] R&D Projects: GA ČR(CZ) GA101/09/1959 Institutional research plan: CEZ:AV0Z20760514 Keywords : flow control * synthetic jet * jet flow Subject RIV: BK - Fluid Dynamics

  2. The Experimental Investigation of Supersymmetry Breaking

    Peskin, Michael E.

    1996-01-01

    If Nature is supersymmetric at the weak interaction scale, what can we hope to learn from experiments on supersymmetric particles? The most mysterious aspect of phenomenological supersymmetry is the mechanism of spontaneous supersymmetry breaking. This mechanism ties the observable pattern of supersymmetric particle masses to aspects of the underlying unified theory at very small distance scales. In this article, I will discuss a systematic experimental program to determine the mechanism of s...

  3. Experimental facilities for plate-out investigations and future work

    The safety of HTR under normal operation and accident conditions, the possibility of inspection, maintenance and repair or decontamination of single primary components as well as the safety of maintenance personnel are essentially determined by the transport- and deposition behaviour of the non gaseous fission - and activation products in the primary loop of the reactor. A comprehensive program has been started in 1969 in KFA in collaboration with various industrial firms and foreign institutions to investigate these problems. The program includes in-pile and out-pile experiments, simulating reactor conditions and also different laboratory experiments and extensive theoretical investigations. The aim of these efforts is to test experimentally the models and computercodes, which are used for prediction of transport and deposition behaviour of fission products for HTR's as well under normal as under accident conditions. Further more a verified dataset is to be established. In this paper a survey is given of the experimental facilities carried out by KFA or in cooperation with KFA

  4. Theoretical and experimental investigations of Chinese evacuated tubular solar collectors

    Qin, Lin; Furbo, Simon

    1999-01-01

    Four different marketed Chinese evacuated tubular solar collectors have been investigated both theoretically and experimentally. The advantages of the investigated solar collectors compared to normal flat plate collectors were elucidated.......Four different marketed Chinese evacuated tubular solar collectors have been investigated both theoretically and experimentally. The advantages of the investigated solar collectors compared to normal flat plate collectors were elucidated....

  5. High range electromagnetic fields. Experimental investigations

    It has been often discussed on the health effects from the electromagnetic fields, and nowadays this theme is particularly controlled and studied by the research-workers. It needs to know what is the risk connected to the exposure to the electromagnetism during a short or a long quantity of time and what are the health pathologies caused by the continue exposure. On one hand the results from epidemiological research can not still define the effect of the dose, on the other hand the legislative frame is variously fragmented and based on cautious concepts. But in this work, under the collaboration of Energy Resources Laboratory in Lausanne and the Geo resources and Territory Department in Turin University, are presented the early results on the experiments got out on high frequency (950 MHZ) in order to give a contribution to the debate between the scientific community and the public opinion

  6. Theoretical And Experimental Investigation Of Reditrons

    Kwan, T. J.; Davis, H. A.; Fulton, R. D.; Sherwood, E. G.

    1988-05-01

    We have carried out theoretical and experimental study to optimize the efficiency of microwave production of the reditron. In the optimal configuration, we have achieved the production of 3.3 GW of microwave radiation at 10.0% efficiency with a very narrow spectrum centered at 2.15 GHz. This is roughly a factor of 3.5 increase in efficiency and about 3 in bandwidth narrowing over conventional vircators. In additon, we found that the use of cavities can achieved bandwidth narrowing, stability of frequency during repeated operation, improvement of mode selectivity.

  7. The experimental investigation of supersymmetry breaking

    If Nature is supersymmetric at the weak interaction scale, what can we hope to learn from experiments on supersymmetric particles? The most mysterious aspect of phenomenological supersymmetry is the mechanism of spontaneous supersymmetry breaking. This mechanism ties the observable pattern of supersymmetric particle masses to aspects of the underlying unified theory at very small distance scales. In this article, I will discuss a systematic experimental program to determine the mechanism of supersymmetry breaking. Both pp and e+e- colliders of the next generation play an essential role

  8. Extra-terrestrial sprites: laboratory investigations in planetary gas mixtures

    Dubrovin, D.; Yair, Y.; Price, C.; Nijdam, S.; Clevis, T.T.J.; Veldhuizen, E.M. van; Ebert, U.

    2012-01-01

    We investigate streamers in gas mixtures representing the atmospheres of Jupiter, Saturn (H2-He) and Venus (CO2-N2). Streamer diameters, velocities, radiance and overall morphology are investigated with fast ICCD camera images. We confirm experimentally the scaling of streamer diameters in these gas

  9. Numerical and experimental investigations on catalytic recombiners

    Numerous containments of European light water reactors (LWR) are equipped with passive auto-catalytic recombiners (PAR). These devices are designed for the removal of hydrogen generated during a severe accident in order to avoid serious damage caused by a detonation. PARs make use of the fact that hydrogen and oxygen react exothermally on catalytic surfaces generating steam and heat even below conventional ignition concentrations and temperatures. Activities at ISR aim at overcoming existing limitations of today's systems. These are e.g. limited conversion capacity or unintended ignition of the gaseous mixture due to overheating of the catalyst elements caused by strong reaction heat generation. Experiments at the REKO facilities are conducted in order to achieve a profound understanding of the processes inside a recombiner, such as reaction kinetics or heat and mass transfer. Innovative PAR designs which may overcome existing limitations can be developed based on the knowledge obtained from these experiments. For the analysis of the processes inside a PAR the numerical code REKO-DIREKT is being developed. The code calculates the local catalyst temperatures and the concentration regression along the catalyst plates. For the validation of the model numerous experiments have been performed with different types of coating and different plate arrangements. The first calculations fit well with the experimental results indicating a proper understanding of the fundamental processes. The paper describes the experiments as well as the numerical model and presents model calculations in comparison with experimental results. (authors)

  10. Environmental epidemiology applied to urban atmospheric pollution: a contribution from the Experimental Air Pollution Laboratory (LPAE)

    André Paulo Afonso de; Braga Alfésio Luis Ferreira; Lin Chin An; Conceição Gleice Margarete de Souza; Pereira Luiz Alberto Amador; Miraglia Simone Georges El Khouri; Böhm György Miklos

    2000-01-01

    Systematic investigation on the effects of human exposure to environmental pollution using scientific methodology only began in the 20th century as a consequence of several environmental accidents followed by an unexpected mortality increase above expected mortality and as a result of observational epidemiological and toxicological studies conducted on animals in developed countries. This article reports the experience of the Experimental Air Pollution Laboratory at the School of Medicine, Un...

  11. Experimental Investigation of Wetting with Magnetic Fluids.

    Manukyan, Selin; Schneider, Marius

    2016-05-24

    Here we report the experimental results of the general wetting behavior of an oil-based ferrofluid and a water-based magnetic paint droplet on a hydrophobic surface under the effect of an external magnetic field. By increasing the magnetic field in the vertical direction, the height of the oil-based ferrofluid droplet increases while the width decreases; on the contrary, under the same circumstances, the height of the water-based magnetic paint droplet decreases whereas the width increases. The wetting behavior of the oil-based ferrofluid and the water-based magnetic paint droplets is evaluated as a function of the contact angle, contact line diameter, and hysteresis curve alterations. Conclusively, a general explanation is given for the contrary behavior of both liquids, and some application processes for future implementations are introduced. PMID:27119597

  12. Experimental investigations of active air bearings

    Santos, Ilmar; Morosi, Stefano

    2012-01-01

    greatest challenges in a high-speed gas bearing design. A great deal of research is devoted to attack such issues, where most propose passive designs such as compliant foil bearings, tilting pad and flexure pivot gas bearings. These solutions proved to be effective in improving static and dynamic......Along with traditional oil lubrication, increasing demand for high-speed applications has renewed attention to gas bearings technology. Traditional aerostatic and aerodynamic gas lubrication has been widely used in a variety of applications, ranging from high-speed spindles to micro and meso......-scale turbomachinery. The present paper deals with experimental rotordynamic testing of a flexible rotor supported by hybrid aerostaticaerodynamic gas journal bearing equipped with an electronic radial air injection system. From a rotordynamic point of view there are two phenomena that limit the widespread of...

  13. Biomass granular screw feeding: An experimental investigation

    Dai, Jianjun; Grace, John R. [Department of Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, BC, V6 T 1Z3 (Canada)

    2011-02-15

    Successful feeding is critical to biomass utilization processes, but difficult due to the heterogeneity, physical properties and moisture content of the particles. The objectives of the present study were to find the mechanisms of blockage in screw feeding and to determine the effects of particle mean size (0.5-15 mm), size distribution, shape, moisture content (10-60%), density and compressibility on biomass particle feeding at room temperature. Wood pellets, sawdust, hog fuel and wood shavings were tested in a screw feeder/lock hopper system previously employed to feed sawdust into a pilot-scale circulating fluidized-bed gasifier. Experimental results showed that large particles, wide size distributions, large bulk densities and high moisture contents generally led to larger torque requirements for screw feeding. The ''choke section'' and seal plug play important roles in determining the torque requirements. (author)

  14. Exploratory experimental investigation of a wave propeller

    Dane, Carl W.

    1992-01-01

    Approved for public release; distribution is unlimited A low-speed wind tunnel investigation was conducted to determine if a small secondary airfoil or wave propeller, oscillating in a rotary plunging motion, could significantly affect the airflow over a lifting airfoil surface to delay the onset of stall. The lifting airfoil shape was a NACA 66(215)-216, chosen for its chordwise pressure port instrumentation. Testing consisted of measuring the pressure distribution of the NACA 66(215)-2...

  15. Experimental investigation of turbine-structure interaction

    Fabre, Romain

    2015-01-01

    This project concerns the fast growing sector of tidal energy. It is carried out with the company Sustainable Marine Energy Ltd currently developing a new concept of tidal turbines. The main purpose of the research is to investigate a phenomenon that was noticed in previous researches: the increase of performances of the turbine due to the presence of the turbine support structure. For this purpose, a physical model was manufactured; it is design to recreate the turbine-p...

  16. Electrically Responsive Surfaces: Experimental and Theoretical Investigations

    2016-01-01

    orientation of the surface-tethered molecules under electroinduced switching, but also provided an in-depth characterization of the system reversibility. Furthermore, the unique support from molecular dynamics (MD) simulations is highlighted. MD simulations with polarizable force fields (FFs), which could give proper description of the charge polarization caused by electrical stimulus, have helped not only back many of the experimental observations, but also to rationalize the mechanism of switching behavior. More importantly, this polarizable FF-based approach can efficiently be extended to light or pH stimulated surfaces when integrated with reactive FF methods. The interplay between experimental and theoretical studies has led to a higher level of understanding of the switchable surfaces, and to a more precise interpretation and rationalization of the observed data. The perspectives on the challenges and opportunities for future progress on stimuli-responsive surfaces are also presented. PMID:27268783

  17. Electrically Responsive Surfaces: Experimental and Theoretical Investigations.

    Cantini, Eleonora; Wang, Xingyong; Koelsch, Patrick; Preece, Jon A; Ma, Jing; Mendes, Paula M

    2016-06-21

    the surface-tethered molecules under electroinduced switching, but also provided an in-depth characterization of the system reversibility. Furthermore, the unique support from molecular dynamics (MD) simulations is highlighted. MD simulations with polarizable force fields (FFs), which could give proper description of the charge polarization caused by electrical stimulus, have helped not only back many of the experimental observations, but also to rationalize the mechanism of switching behavior. More importantly, this polarizable FF-based approach can efficiently be extended to light or pH stimulated surfaces when integrated with reactive FF methods. The interplay between experimental and theoretical studies has led to a higher level of understanding of the switchable surfaces, and to a more precise interpretation and rationalization of the observed data. The perspectives on the challenges and opportunities for future progress on stimuli-responsive surfaces are also presented. PMID:27268783

  18. Investigation of Appropriate Refractory Material for Laboratory Electritic Resistrance Furnance

    J.B Agboola

    2009-07-01

    Full Text Available There have been numerous efforts to increase the local content of furnaces; hence the choice of appropriate refractory material for lining of locally manufactured furnaces has remained a major concern. This research work investigates the choice of appropriate local refractory material for the lining of laboratory electric resistance furnace.Electric resistance furnaces are extensively used in the laboratory for heat treatment of metals and alloys. Refractory binders such as silicon carbide were experimented upon for strength and resistance to high temperature.The results obtained showed that Kankara fireclay containing 15% SiC ( 5.70 % linear shrinkage , 46.2% apparent porosity, 1.77gkm³ Bulk density, 18 cycles of spalling tests at 1300°C, 5.253KN/m² of cold strength has appropriate properties for producing grooved bricks for lining of laboratory electric resistance Furnace.

  19. Experimental investigation on fracture of layered plates

    Agnihotri, Servesh; Parameswaran, Venkitanarayanan

    2015-03-01

    Layered structures, used in many applications such as windshields, thermal protection systems, heavy armor etc., are comprised of layers having different elastic and fracture properties. Present study focuses on understanding the behavior of cracks in a layered plate oriented in such a way that there are property jumps across the crack front. Two layer plates were fabricated by joining Polymethylmethacrylate (PMMA) and epoxy sheets using an epoxy based adhesive (Araldite). Single edge notched specimens were subjected to mixed mode loading using the asymmetric four point bending configuration. The results of the study indicated that the failure in two layer plates is progressive in nature. Crack extension starts in the most vulnerable layer (epoxy) first and the crack grows in a sequence of jumps and arrests in this layer. Once this crack reaches a particular length the crack in the second layer starts extending resulting in final failure of the plate. Similar sequence of events was observed in the case of dynamically loaded samples. The predictions of the load at which epoxy crack starts growing and the angle at which the crack grows using the maximum tensile stress criteria were in reasonable agreement with the experimentally observed values.

  20. Experimental investigation of planar ion traps

    Pearson, C E; Brown, K R; Chuang, I L; Leibrandt, D R; Mallard, W J

    2005-01-01

    Chiaverini et al. [Quant. Inf. Comput. 5, 419 (2005)] recently suggested a linear Paul trap geometry for ion trap quantum computation that places all of the electrodes in a plane. Such planar ion traps are compatible with modern semiconductor fabrication techniques and can be scaled to make compact, many zone traps. In this paper we present an experimental realization of planar ion traps using electrodes on a printed circuit board to trap linear chains of tens of 0.44 micron diameter charged particles in a vacuum of 15 Pa (0.1 torr). With these traps we address concerns about the low trap depth of planar ion traps and develop control electrode layouts for moving ions between trap zones without facing some of the technical difficulties involved in an atomic ion trap experiment. Specifically, we use a trap with 36 zones (77 electrodes) arranged in a cross to demonstrate loading from a traditional four rod linear Paul trap, linear ion movement, splitting and joining of ion chains, and movement of ions through in...

  1. Experimental investigation on flow modes of electrospinning

    Ting Si; Guang-Bin Li; Xing-Xing Chen; Rui-Jun Tian; Xie-Zhen Yin

    2012-01-01

    Electrospinning experiments are performed by using a set of experimental apparatus,a stroboscopic system is adopted for capturing instantaneous images of the conejet configuration.The cone and the jet of aqueous solutions of polyethylene oxide (PEO) are formed from an orifice of a capillary tube under the electric field.The viscoelastic constitutive relationship of the PEO solution is measured and discussed.The phenomena owing to the jet instability are described,five flow modes and corresponding structures are obtained with variations of the fluid flow rate Q,the electric potential U and the distance h from the orifice of the capillary tube to the collector.The flow modes of the cone-jet configuration involves the steady bending mode,the rotating bending mode,the swinging rotating mode,the blurring bending mode and the branching mode.Regimes in the Q-U plane of the flow modes are also obtained.These results may provide the fundamentals to predict the operating conditions expected in practical applications.

  2. Experimental investigation of hydrogen peroxide RF plasmas

    Barni, R.; Decina, A.; Zanini, S.; D'Orazio, A.; Riccardi, C.

    2016-04-01

    This work reports a detailed experimental study of the plasma properties in low pressure RF discharges in hydrogen peroxide and a comparison with argon under the same operating conditions. H2O2 plasmas have been proposed for sterilization purposes. Electrical properties of the discharge were shown to be similar, as for the RF and DC voltages of the driving electrode. Bulk plasma volume remains stable, concentrated in an almost cylindrical region between the two facing electrodes. It was found that the electron temperature is almost uniform across the plasma and independent of the power level. This is higher than in argon discharges: T e  =  4.6  ±  0.9 eV versus T e  =  3.3  ±  1.1 eV. The plasma density increases almost linearly with the power level and a substantial negative ion component has been ruled out in hydrogen peroxide. Dissociation in the plasma gas phase was revealed by atomic hydrogen and hydroxyl radical emission in the discharge spectra. Emission from hydroxyl and atomic oxygen demonstrates that oxidizing radicals are produced by hydrogen peroxide discharges, revealing its usefulness for plasma processing other than sterilization, for instance to increase polymer film surface energy. On the other hand, argon could be considered as a candidate for the sterilization purposes due to the intense production of UV radiation.

  3. Experimental Investigation of Thruster Cathode Physics

    Crofton, Mark

    2004-11-01

    Advanced ion propulsion technologies are being developed under the Nuclear Electric Xenon Ion System (NEXIS) program for use in outer planet exploration. A revolutionary approach to thruster cathode design is dictated by the very high lifetime and propellant throughput requirements for nuclear electric applications. In conventional dispenser hollow cathodes used in thrusters, processes leading to depletion, inadequate transport, or insufficient production of barium are among those limiting the lifetime. A reservoir hollow cathode is being developed to address each of these failure mechanisms, exploiting four design variables - matrix material, source material, geometry, and thermal design - to essentially eliminate established failure modes. The very long anticipated lifetime necessitates new life validation methods to augment or replace the conventional lifetest approach. One important tool for quickly evaluating design changes is the ability to measure barium density inside a hollow cathode and/or in the plume. The dependence of barium density on temperature and other factors is an extremely important indicator of cathode health, particularly if the ratio Ba:BaO is also obtained. Comparison of barium production for reservoir and conventional cathodes will enable an assessment of the efficacy of reservoir designs and the goal of reducing barium consumption at a given emission current level. This study describes benchmark measurements made on a conventional cathode previously operated in a 20-kW NEXIS laboratory engine. Data on cathode operation and life-limiting processes were obtained through direct, real-time monitoring of atoms and molecules. A high-resolution, tunable laser system was employed to detect absorption of the low-density barium atoms inside the cathode. The plume was monitored also, using a quadrupole mass spectrometer to monitor multiple species and measure ion charge ratios. Data obtained with retarding potential analyzers or other means are

  4. Experimental Investigation of the Loss Coefficients in a Linear Cascade

    Taghavi-Zenouz, Reza; Etemadi, Majed; Nabati, Mehdi

    2014-06-01

    This paper reports results of experimental investigations on a linear cascade of axial compressor blades. Experiments were conducted in an open circuit subsonic wind tunnel of Aerodynamics Research Laboratory of the Iran University of Science and Technology. Different Reynolds numbers based on the blade chord length were examined, ranging from 80,000 to 500,000. Flow incidences were changed between -8 to +8 degrees with 2 degrees intervals. Freestream turbulence intensity was changed between 1.25 to 4 percent corresponding to different mesh screens mounted upstream of the test model. All the above flow conditions provided to establish various flow regimes, in terms of fully laminar and transitional flows, around the blades. At a specified range of Reynolds numbers laminar separation bubble/bubbles occurred over the blade solid walls. Surface pressure distributions were measured utilizing a computerized data acquisition system. Fluctuating velocities were also measured at various positions around the separation bubble zone, using hot film anemometry. Surface oil flow visualization was carried out for some selected flow conditions. Experimental results were used to study boundary layer characteristics and to determine variations of loss coefficient with each of Reynolds number, flow incidence and turbulence intensity parameters for the test model.

  5. Experimental Investigation of Particle Deagglomeration using Turbulence

    The effect of turbulence on powder aerosol deagglomeration was investigated. Two impinging jets were used to generate turbulence. Lactose particles, whose fully dispersed fine particle fraction (FPF) - number percentage of the particles whose diameter smaller than 5 μm- is above 90 %, were applied as aerosol powder. The particle size distribution after the dispersion unit were measured by using phase Doppler anemometer (PDA) and turbulence level were quantified at the impingement point of two jets with laser Doppler anemometer. As the turbulence level increases turbulent time and length scales decrease, and the ratio of fine particle fraction (FPF) increases from 36% to 86%.

  6. Experimental Investigation of Using Fuel Additives - Alcohol

    S.M. Fayyad

    2010-01-01

    This research presents an investigation of the effects of ethanol addition to low octane numbergasoline, on the fuel octane number and on the performance of the engine. In this study, the tested gasoline(octane number = 90) is blended with five different percentages of ethanol, namely 3, 6, 9, 12 and 15% onvolume basis. Then these fuel blends, as well as the base gasoline fuel, w ere burnt in the tested engine. It isfound that the octane number of gasoline increases continuously and linearly ...

  7. Experimental Investigation of Using Fuel Additives - Alcohol

    S.M. Fayyad

    2010-03-01

    Full Text Available This research presents an investigation of the effects of ethanol addition to low octane numbergasoline, on the fuel octane number and on the performance of the engine. In this study, the tested gasoline(octane number = 90 is blended with five different percentages of ethanol, namely 3, 6, 9, 12 and 15% onvolume basis. Then these fuel blends, as well as the base gasoline fuel, w ere burnt in the tested engine. It isfound that the octane number of gasoline increases continuously and linearly with increasing the ethanolpercentage in gasoline. Hence, ethanol is an effective compound for increasing the value of the octane numberof gasoline. Also, it is also noticed that the best performance of the engine was obtained when 15% of ethanolwas used in the gasoline blend.

  8. Experimental investigation of a flapping wing model

    Hubel, Tatjana Y.; Tropea, Cameron

    The main objective of this research study was to investigate the aerodynamic forces of an avian flapping wing model system. The model size and the flow conditions were chosen to approximate the flight of a goose. Direct force measurements, using a three-component balance, and PIV flow field measurements parallel and perpendicular to the oncoming flow, were performed in a wind tunnel at Reynolds numbers between 28,000 and 141,000 (3-15 m/s), throughout a range of reduced frequencies between 0.04 and 0.20. The appropriateness of quasi-steady assumptions used to compare 2D, time-averaged particle image velocimetry (PIV) measurements in the wake with direct force measurements was evaluated. The vertical force coefficient for flapping wings was typically significantly higher than the maximum coefficient of the fixed wing, implying the influence of unsteady effects, such as delayed stall, even at low reduced frequencies. This puts the validity of the quasi-steady assumption into question. The (local) change in circulation over the wing beat cycle and the circulation distribution along the wingspan were obtained from the measurements in the tip and transverse vortex planes. Flow separation could be observed in the distribution of the circulation, and while the circulation derived from the wake measurements failed to agree exactly with the absolute value of the circulation, the change in circulation over the wing beat cycle was in excellent agreement for low and moderate reduced frequencies. The comparison between the PIV measurements in the two perpendicular planes and the direct force balance measurements, show that within certain limitations the wake visualization is a powerful tool to gain insight into force generation and the flow behavior on flapping wings over the wing beat cycle.

  9. Experimental investigation of a flapping wing model

    Hubel, Tatjana Y.; Tropea, Cameron [Technische Universitaet Darmstadt, Fachgebiet Stroemungslehre und Aerodynamik, Darmstadt (Germany)

    2009-05-15

    The main objective of this research study was to investigate the aerodynamic forces of an avian flapping wing model system. The model size and the flow conditions were chosen to approximate the flight of a goose. Direct force measurements, using a three-component balance, and PIV flow field measurements parallel and perpendicular to the oncoming flow, were performed in a wind tunnel at Reynolds numbers between 28,000 and 141,000 (3-15 m/s), throughout a range of reduced frequencies between 0.04 and 0.20. The appropriateness of quasi-steady assumptions used to compare 2D, time-averaged particle image velocimetry (PIV) measurements in the wake with direct force measurements was evaluated. The vertical force coefficient for flapping wings was typically significantly higher than the maximum coefficient of the fixed wing, implying the influence of unsteady effects, such as delayed stall, even at low reduced frequencies. This puts the validity of the quasi-steady assumption into question. The (local) change in circulation over the wing beat cycle and the circulation distribution along the wingspan were obtained from the measurements in the tip and transverse vortex planes. Flow separation could be observed in the distribution of the circulation, and while the circulation derived from the wake measurements failed to agree exactly with the absolute value of the circulation, the change in circulation over the wing beat cycle was in excellent agreement for low and moderate reduced frequencies. The comparison between the PIV measurements in the two perpendicular planes and the direct force balance measurements, show that within certain limitations the wake visualization is a powerful tool to gain insight into force generation and the flow behavior on flapping wings over the wing beat cycle. (orig.)

  10. Experimental Investigation of the Decay from A Ship's Propeller

    W. Lam; G. A. Hamill; SONG Yong-chen; D. J. Robinson; S. Raghunathan

    2011-01-01

    In the present study, an experimental investigation of the decay of the maximum velocity and its turbulent characteristics behind a ship propeller, in "bollard pull" condition (zero speed of advance), is reported. Velocity measurements were performed in laboratory by use of a Laser Doppler Anemometry (LDA) measurement system. Earlier researchers described that the maximum axial velocity is constant at the initial stage of a ship's propeller jet (Fuehrer and Romisch, 1977; Blaauw and van de Kaa, 1978; Berger et al., 1981; Verhey, 1983) as reported in a pure water jet (Albert.son et al., 1950; Lee et al., 2002; Dai, 2005), but a number of researchers disagreed with the constant velocity assumption. The present study found that the maximum axial velocity decays in the zone of flow establishment and the zone of established flow with different rates. The investigation provides an insight into the decays of both the maximum velocity and the maximum turbulent fluctuation in axial, tangential and radial components and the decay of the maximum turbulent kinetic energy. Empirical equations are proposed to allow coastal engineers to estimate the jet characteristics from a ship's propeller.

  11. Experimental Investigation of Turbine Vane Heat Transfer for Alternative Fuels

    Nix, Andrew Carl [West Virginia Univ., Morgantown, WV (United States)

    2015-03-23

    The focus of this program was to experimentally investigate advanced gas turbine cooling schemes and the effects of and factors that contribute to surface deposition from particulate matter found in coal syngas exhaust flows on turbine airfoil heat transfer and film cooling, as well as to characterize surface roughness and determine the effects of surface deposition on turbine components. The program was a comprehensive, multi-disciplinary collaborative effort between aero-thermal and materials faculty researchers and the Department of Energy, National Energy Technology Laboratory (NETL). The primary technical objectives of the program were to evaluate the effects of combustion of syngas fuels on heat transfer to turbine vanes and blades in land-based power generation gas turbine engines. The primary questions to be answered by this investigation were; What are the factors that contribute to particulate deposition on film cooled gas turbine components? An experimental program was performed in a high-temperature and pressure combustion rig at the DOE NETL; What is the effect of coal syngas combustion and surface deposition on turbine airfoil film cooling? Deposition of particulate matter from the combustion gases can block film cooling holes, decreasing the flow of the film coolant and the film cooling effectiveness; How does surface deposition from coal syngas combustion affect turbine surface roughness? Increased surface roughness can increase aerodynamic losses and result in decreased turbine hot section efficiency, increasing engine fuel consumption to maintain desired power output. Convective heat transfer is also greatly affected by the surface roughness of the airfoil surface; Is there any significant effect of surface deposition or erosion on integrity of turbine airfoil thermal barrier coatings (TBC) and do surface deposits react with the TBC in any way to decrease its thermal insulating capability? Spallation and erosion of TBC is a persistent problem in

  12. Experimental and numerical investigation of non-neutral complex plasmas

    Romé, M.; Cavaliere, F.; Cavenago, M.; Ikram, M.; Lepreti, F.; Maero, G.; Paroli, B.; Pozzoli, R.

    2013-03-01

    A plasma of particles with the same sign of charge, can be easily confined under ultra-high vacuum conditions in Penning-Malmberg traps, where the time evolution of the system is monitored for very long times by means of electrostatic and optical diagnostic systems. Complex (dusty) plasmas are ionized gases that contain a distribution of micrometer-sized particles with a surface charge of the order of a few thousand electron charges. The interplay between a wide range of scales in time and space gives rise to new characteristic physical phenomena. Laboratory complex plasmas generally satisfy a global (quasi-)neutrality condition. A different concept is represented by a non-neutral complex plasma. To investigate the dynamics of this system, we are currently developing the DuEl (Dust-Electron) device, where negatively charged dust particles will be present together with a population of electrons. The experimental set-up will include a dust injection system and a Penning-Malmberg trap for the confinement of the dust-contaminated electron plasma. We describe here the main physical aims of the project and the present design of the apparatus. To support the experimental project, we have been developing a specifically tailored two-dimensional 'hybrid' Particle-In-Cell code. Using polar cylindrical coordinates, the code aims to investigate the transverse dynamics of a magnetized electron plasma contaminated by a massive, charged species. A mass-less fluid approximation for the electron population is exploited, while the dust component is treated with a kinetic description, also including the gravitational force. The preliminary results of systematic studies on the effects of heavy (magnetized or non-magnetized) dust grains on the equilibrium and stability properties of the electron fluid are presented. The implementation of other characteristic phenomena of interest, e.g. residual gas friction and dust charge fluctuations, is also under development.

  13. Experimental and numerical investigation of non-neutral complex plasmas

    Rome, M.; Cavaliere, F.; Maero, G.; Paroli, B.; Pozzoli, R. [INFN Sezione di Milano and Dipartimento di Fisica, Universita degli Studi di Milano, Via Celoria 16, I-20133 Milano (Italy); Cavenago, M. [INFN Laboratori Nazionali di Legnaro, Viale dell' Universita 2, I-35020 Legnaro (Italy); Ikram, M. [INFN Sezione di Milano and Dipartimento di Fisica, Universita degli Studi di Milano, Via Celoria 16, I-20133 Milano, Italy and Department of Physics, Hazara University, 21300 Mansehra (Pakistan); Lepreti, F. [Dipartimento di Fisica, Universita della Calabria and CNISM Unita di Cosenza, Ponte P. Bucci 31C, I-87036 Rende (Italy)

    2013-03-19

    A plasma of particles with the same sign of charge, can be easily confined under ultra-high vacuum conditions in Penning-Malmberg traps, where the time evolution of the system is monitored for very long times by means of electrostatic and optical diagnostic systems. Complex (dusty) plasmas are ionized gases that contain a distribution of micrometer-sized particles with a surface charge of the order of a few thousand electron charges. The interplay between a wide range of scales in time and space gives rise to new characteristic physical phenomena. Laboratory complex plasmas generally satisfy a global (quasi-)neutrality condition. A different concept is represented by a non-neutral complex plasma. To investigate the dynamics of this system, we are currently developing the DuEl (Dust-Electron) device, where negatively charged dust particles will be present together with a population of electrons. The experimental set-up will include a dust injection system and a Penning-Malmberg trap for the confinement of the dust-contaminated electron plasma. We describe here the main physical aims of the project and the present design of the apparatus. To support the experimental project, we have been developing a specifically tailored two-dimensional 'hybrid' Particle-In-Cell code. Using polar cylindrical coordinates, the code aims to investigate the transverse dynamics of a magnetized electron plasma contaminated by a massive, charged species. A mass-less fluid approximation for the electron population is exploited, while the dust component is treated with a kinetic description, also including the gravitational force. The preliminary results of systematic studies on the effects of heavy (magnetized or non-magnetized) dust grains on the equilibrium and stability properties of the electron fluid are presented. The implementation of other characteristic phenomena of interest, e.g. residual gas friction and dust charge fluctuations, is also under development.

  14. Experimental and numerical investigation of non-neutral complex plasmas

    A plasma of particles with the same sign of charge, can be easily confined under ultra-high vacuum conditions in Penning-Malmberg traps, where the time evolution of the system is monitored for very long times by means of electrostatic and optical diagnostic systems. Complex (dusty) plasmas are ionized gases that contain a distribution of micrometer-sized particles with a surface charge of the order of a few thousand electron charges. The interplay between a wide range of scales in time and space gives rise to new characteristic physical phenomena. Laboratory complex plasmas generally satisfy a global (quasi-)neutrality condition. A different concept is represented by a non-neutral complex plasma. To investigate the dynamics of this system, we are currently developing the DuEl (Dust-Electron) device, where negatively charged dust particles will be present together with a population of electrons. The experimental set-up will include a dust injection system and a Penning-Malmberg trap for the confinement of the dust-contaminated electron plasma. We describe here the main physical aims of the project and the present design of the apparatus. To support the experimental project, we have been developing a specifically tailored two-dimensional 'hybrid' Particle-In-Cell code. Using polar cylindrical coordinates, the code aims to investigate the transverse dynamics of a magnetized electron plasma contaminated by a massive, charged species. A mass-less fluid approximation for the electron population is exploited, while the dust component is treated with a kinetic description, also including the gravitational force. The preliminary results of systematic studies on the effects of heavy (magnetized or non-magnetized) dust grains on the equilibrium and stability properties of the electron fluid are presented. The implementation of other characteristic phenomena of interest, e.g. residual gas friction and dust charge fluctuations, is also under development.

  15. Road Traffic Congestion and Public Information: An Experimental Investigation

    Anthony Ziegelmeyer; Frédéric Koessler; Kene Boun My; Laurent Denant-Boèmont

    2007-01-01

    This paper reports two laboratory studies designed to study the impact of public information about past departure rates on congestion levels and travel costs. Our experimental design is based on a discrete version of Arnott, de Palma, and Lindsey’s (1990) bottleneck model where subjects have to choose their departure time in order to reach a common destination. Experimental treatments in our first study differ in terms of the level of public information on past departure rates and the relativ...

  16. Students' assessment of interactive distance experimentation in nuclear reactor physics laboratory education

    Malkawi, Salaheddin; Al-Araidah, Omar

    2013-10-01

    Laboratory experiments develop students' skills in dealing with laboratory instruments and physical processes with the objective of reinforcing the understanding of the investigated subject. In nuclear engineering, where research reactors play a vital role in the practical education of students, the high cost and long construction time of research reactors limit their accessibility to few educational programmes around the world. The concept of the Internet Reactor Laboratory (IRL) was introduced earlier as a new approach that utilises distance education in nuclear reactor physics laboratory education. This paper presents an initial assessment of the implementation of the IRL between the PULSTAR research reactor at North Carolina State University in the USA and the Department of Nuclear Engineering at Jordan University of Science and Technology (JUST) in Jordan. The IRL was implemented in teaching the Nuclear Reactor laboratory course for two semesters. Feedback from surveyed students verifies that the outcomes attained from using IRL in experimentation are comparable to that attainable from other on-campus laboratories performed by the students.

  17. Experimental and Theoretical Investigations of Wet Flue Gas Desulphurisation

    Kiil, Søren

    temperature in the interval 313 - 333 K, pertinent for full-scale wet FGD packed towers. The possibility of co-firing straw and coal was investigated in a full-scale power plant. No ef-fects on the overall performance of the wet FGD plant were observed, though laboratory ex-periments with fine dust and fly......-scale experiments. In the theoretical part of the work, the laboratory and pilot plant observations are investigated using mathematical modelling.The mechanism underlying the rate of dissolution of finely grinded limestone particles was examined in a laboratory batch apparatus using acid titration. Three Danish...

  18. Experimental methods for laboratory-scale ensilage of lignocellulosic biomass

    Anaerobic fermentation is a potential storage method for lignocellulosic biomass in biofuel production processes. Since biomass is seasonally harvested, stocks are often dried or frozen at laboratory scale prior to fermentation experiments. Such treatments prior to fermentation studies cause irreversible changes in the plant cells, influencing the initial state of biomass and thereby the progression of the fermentation processes itself. This study investigated the effects of drying, refrigeration, and freezing relative to freshly harvested corn stover in lab-scale ensilage studies. Particle sizes, as well as post-ensilage drying temperatures for compositional analysis, were tested to identify the appropriate sample processing methods. After 21 days of ensilage the lowest pH value (3.73 ± 0.03), lowest dry matter loss (4.28 ± 0.26 g. 100 g-1DM), and highest water soluble carbohydrate (WSC) concentrations (7.73 ± 0.26 g. 100 g-1DM) were observed in control biomass (stover ensiled within 12 h of harvest without any treatments). WSC concentration was significantly reduced in samples refrigerated for 7 days prior to ensilage (3.86 ± 0.49 g. 100 g−1 DM). However, biomass frozen prior to ensilage produced statistically similar results to the fresh biomass control, especially in treatments with cell wall degrading enzymes. Grinding to decrease particle size reduced the variance amongst replicates for pH values of individual reactors to a minor extent. Drying biomass prior to extraction of WSCs resulted in degradation of the carbohydrates and a reduced estimate of their concentrations. The methods developed in this study can be used to improve ensilage experiments and thereby help in developing ensilage as a storage method for biofuel production. -- Highlights: ► Laboratory-scale methods to assess the influence of ensilage biofuel production. ► Drying, freezing, and refrigeration of biomass influenced microbial fermentation. ► Freshly ensiled stover exhibited

  19. Experimental investigation of jet pulse control on flexible vibrating structures

    Karaiskos, Grigorios; Papanicolaou, Panos; Zacharopoulos, Dimitrios

    2016-08-01

    The feasibility of applying on-line fluid jet pulses to actively control the vibrations of flexible structures subjected to harmonic and earthquake-like base excitations provided by a shake table is explored. The operating principles and capabilities of the control system applied have been investigated in a simplified small-scale laboratory model that is a mass attached at the top free end of a vertical flexible slender beam with rectangular cross-section, the other end of which is mounted on an electrodynamic shaker. A pair of opposite jets placed on the mass at the top of the cantilever beam applied the appropriate forces by ejecting pressurized air pulses controlled by on/off solenoid electro-valves via in house developed control software, in order to control the vibration caused by harmonic, periodic and random excitations at pre-selected frequency content provided by the shaker. The dynamics of the structure was monitored by accelerometers and the jet impulses by pressure sensors. The experimental results have demonstrated the effectiveness and reliability of Jet Pulse Control Systems (JPCS). It was verified that the measured root mean square (RMS) vibration levels of the controlled structure from harmonic and earthquake base excitations, could be reduced by approximately 50% and 33% respectively.

  20. Experimental and analytical investigation of a fluidic power generator

    Sarohia, V.; Bernal, L.; Beauchamp, R. B.

    1981-01-01

    A combined experimental and analytical investigation was performed to understand the various fluid processes associated with the conversion of flow energy into electric power in a fluidic generator. Experiments were performed under flight-simulated laboratory conditions and results were compared with those obtained in the free-flight conditions. It is concluded that the mean mass flow critically controlled the output of the fluidic generator. Cross-correlation of the outputs of transducer data indicate the presence of a standing wave in the tube; the mechanism of oscillation is an acoustic resonance tube phenomenon. A linearized model was constructed coupling the flow behavior of the jet, the jet-layer, the tube, the cavity, and the holes of the fluidic generator. The analytical results also show that the mode of the fluidic power generator is an acoustical resonance phenomenon with the frequency of operation given by f approx = a/4L, where f is the frequency of jet swallowing, a is the average speed of sound in the tube, and L is the length of the tube. Analytical results further indicated that oscillations in the fluidic generator are always damped and consequently there is a forcing of the system in operation.

  1. Experimental investigation of surface litter ignition by bark firebrands

    Filkov, Alexander; Kasymov, Denis; Zima, Vladislav; Matvienko, Oleg

    2016-01-01

    Probability and conditions for ignition of surface litter (pine needles) caused by firebrands is studied in the laboratory conditions. For modeling of firebrands, pine bark of various sizes 10×10, 15×15, 20×20, 25×25, 30×30 mm2 and 5 mm in thickness is used. The experiment was conducted in the absence of wind and at different wind velocities: 1, 1.5, 2 and 3 m/s. To conduct investigations, an experimental setup was constructed for generation of firebrands and their impact on surface litter. The results of experiments have shown that the increase in air velocity leads to the increase in probability of surface litter ignition. Thus, wind plays a role of catalyst in the ignition process, bringing an oxidizing agent to firebrands and supporting the process of smoldering. However, if the wind velocity is insufficient for ignition, then there is only the process of smoldering. The area of "uncertainty", where there is smoldering of surface litter without transition to ignition, is found to decrease with increasing the wind velocity. Based on the received results, it can be concluded that the ignition curve of surface liter by firebrands is nonlinear and depends on the wind velocity. At the same time, there is no smoldering and ignition of surface litter for all the wind velocities and the particles with a size of 10 × 10 mm2, regardless of their number.

  2. Children's recantation of adult wrongdoing: An experimental investigation.

    Malloy, Lindsay C; Mugno, Allison P

    2016-05-01

    Child maltreatment cases often hinge on a child's word versus a defendant's word, making children's disclosures crucially important. There is considerable debate concerning why children recant allegations, and it is imperative to examine recantation experimentally. The purpose of this laboratory analogue investigation was to test (a) how often children recant true allegations of an adult's wrongdoing after disclosing and (b) whether children's age and caregiver supportiveness predict recantation. During an interactive event, 6- to 9-year-olds witnessed an experimenter break a puppet and were asked to keep the transgression a secret. Children were then interviewed to elicit a disclosure of the transgression. Mothers were randomly assigned to react supportively or unsupportively to this disclosure, and children were interviewed again. We coded children's recantations (explicit denials of the broken puppet after disclosing) and changes in their forthcomingness (shifts from denial or claims of lack of knowledge/memory to disclosure and vice versa) in free recall and in response to focused questions about the transgression. Overall, 23.3% of the children recanted their prior disclosures (46% and 0% in the unsupportive and supportive conditions, respectively). No age differences in recantation rates emerged, but 8- and 9-year-olds were more likely than 6- and 7-year-olds to maintain their recantation throughout Interview 2. Children whose mothers reacted supportively to disclosure became more forthcoming in Interview 2, and those whose mothers reacted unsupportively became less forthcoming. Results advance theoretical understanding of how children disclose negative experiences, including sociomotivational influences on their reports, and have practical implications for the legal system. PMID:26771375

  3. Laboratory Investigations on Estuary Salinity Mixing: Preliminary Analysis

    F. H. Nuryazmeen

    2014-05-01

    Full Text Available Estuaries are bodies of water along the coasts that are formed when fresh water from rivers flows into and mixes with salt water from the ocean. The estuaries serve as a habitat to some aquatic lives, including mangroves. Human-induced activities such as dredging of shipping lanes along the bottom estuarine, the disposal of industrial wastes into the water system and shoreline development influence estuarine dynamics which include mixing process. These activities might contribute to salinity changes and further adversely affect the estuarine ecosystem. In order to study at the characteristics of the mixing between salt water (estuary and freshwater (river, a preliminary investigation had been done in the laboratory. Fresh water was released from one end of the flume and overflowing at weir at the other end. Meanwhile, salt water was represented by the red dye tracer released through a weir and intruded upstream as a gravity current. The isohalines are plotted to see the salinity patterns. Besides, to examine the spatial and temporal salinity profiles along the laboratory investigations, the plotted graphs have been made. The results show that the changes in salinity level along the flume due to mixing between fresh water and salt water. This showed typical salt-wedge estuary characteristics.

  4. Numerical and experimental investigation of geometric parameters in projection welding

    Kristensen, Lars; Zhang, Wenqi; Bay, Niels

    2000-01-01

    parameters by numerical modeling and experimental studies. SORPAS, an FEM program for numerical modeling of resistance welding, is developed as a tool to help in the phase of product design and process optimization in both spot and projection welding. A systematic experimental investigation of projection...

  5. Randomized block experimental designs can increase the power and reproducibility of laboratory animal experiments.

    Festing, Michael F W

    2014-01-01

    Randomized block experimental designs have been widely used in agricultural and industrial research for many decades. Usually they are more powerful, have higher external validity, are less subject to bias, and produce more reproducible results than the completely randomized designs typically used in research involving laboratory animals. Reproducibility can be further increased by using time as a blocking factor. These benefits can be achieved at no extra cost. A small experiment investigating the effect of an antioxidant on the activity of a liver enzyme in four inbred mouse strains, which had two replications (blocks) separated by a period of two months, illustrates this approach. The widespread failure to use these designs more widely in research involving laboratory animals has probably led to a substantial waste of animals, money, and scientific resources and slowed down the development of new treatments for human and animal diseases. PMID:25541548

  6. Experimental investigation of subsonic combustion driven MHD generator performance

    McClaine, A. W.; Swallom, D. W.; Kessler, R.

    1984-01-01

    Future mature combined cycle MHD/steam electrical power plants may use subsonic flow trains. To provide a data base of subsonic generator design and operating experience an experimental program was begun in 1977 at the Avco Everett Research Laboratory. During this program an MHD generator was operated with a subsonic flow train under both Faraday and diagonal loads. This paper reviews the work performed under this program and the results obtained.

  7. An Inquiry-Based Density Laboratory for Teaching Experimental Error

    Prilliman, Stephen G.

    2012-01-01

    An inquiry-based laboratory exercise is described in which introductory chemistry students measure the density of water five times using either a beaker, a graduated cylinder, or a volumetric pipet. Students are also assigned to use one of two analytical balances, one of which is purposefully miscalibrated by 5%. Each group collects data using…

  8. Experimental econophysics properties and mechanisms of laboratory markets

    Huang, Ji-Ping

    2015-01-01

    Experimental Econophysics describes the method of controlled human experiments, which is developed by physicists to study some problems in economics or finance, namely, stylized facts, fluctuation phenomena, herd behavior, contrarian behavior, hedge behavior, cooperation, business cycles, partial information, risk management, and stock prediction. Experimental econophysics together with empirical econophysics are two branches of the field of econophysics. The latter one has been extensively discussed in the existing books, while the former one has been seldom touched. In this book, the author will focus on the branch of experimental econophysics. Empirical econophysics is based on the analysis of data in real markets by using some statistical tools borrowed from traditional statistical physics. Differently, inspired by the role of controlled experiments and system modelling (for computer simulations and/or analytical theory) in developing modern physics, experimental econophysics specially relies on controlle...

  9. Field studies, laboratory experiments, and modeling investigations in fractured media

    Groundwater flow and radionuclide migration are two critical factors in determining the performance of a high-level nuclear waste (HLW) repository. Flow and transport in fractured media is a complex problem that must be addressed by both the site characterization programs and predictive models. The Repository Technology Program is investigating three aspects of the problem in cooperative efforts with Canada and Sweden as well as in international programs such as INTRAVAL. The methodologies and techniques developed in these programs can be applied to any site investigation that must consider fracture flow and transport of radionuclides along discrete fractures. Laboratory experiments are being performed in cooperation with Atomic Energy of Canada, Limited (AECL) on a large block of granite (∼1 m square) with a discrete fracture to investigate dispersion and diffusion along the fracture. Nonreactive and reactive tracers are used in the experiments. Tracers that include uranine, iodine, and cesium are injected under controlled gradients and sampled uniformly along the fracture discharge surface. Results of the nonreactive tracer experiments will be used to calibrate a radionuclide transport code (FRACFLO) recently developed at Battelle's Office of Waste Technology Development. The calibrated models will then be used to predict the results of experiments that use reactive tracers. The experiment and associated modeling are being considered for use as a test case in the INTRAVAL program

  10. Experimental investigation of rubble mound breakwaters for wave energy conversion

    Luppa, C.; Contestabile, P.; Cavallaro, L.;

    2015-01-01

    The paper describes recent laboratory investigation on the breakwater integrated device named “OBREC” (Overtopping BReakwater for Energy Conversion). This technology recently appeared on the wave energy converter scene as an executive outcome of improving composite seawalls by including overtoppi...

  11. Investigation of Sulfate Attack by Experimental and Thermodynamic Means

    Kunther, Wolfgang

    2012-01-01

    This work investigates sulfate attack in complex sulfate environments by exposing different binder types to various sulfate solutions and comparing predicted phase and volume changes with experimental data. The most important aspects of this work can be grouped in three topics: The comparison of the predicted volume increase with the experimentally observed length changes. This part of the work shows that volume increase cannot be linked direct...

  12. Possible experimental investigation of the phenomenon of anomalous ionization

    We discuss the possibility of investigating experimentally in the upper ionosphere the critical velocity phenomenon. This occurs when a cloud of neutral gas interacts with plasma in a transverse magnetic field. We determine the region in experimental parameter space (flow rate of the gas, plasma density, etc.) where we might anticipate the occurrence of a self-sustaining beam-plasma discharge. We consider quantitatively the dynamics of the discharge process

  13. Experimental investigation of coarse-grained particles in pipes

    Vlasák, P.; Chára, Z.; Konfršt, J. (Jiří); Kysela, B. (Bohuš)

    2013-01-01

    The effect of solid concentration and mixture velocity on the flow behaviour and pressure drops of coarse-grained particle-water mixtures in the turbulent flow was experimentally investigated. Concentration distribution in the pipe cross-section was also studied. Graded basalt pebbles as a model of solid particles were studied on an experimental pipe loop with horizontal, vertical, and inclined sections of smooth stainless steel pipes of inner diameter D = 100 mm. The study revealed that the ...

  14. Experimental investigations of thermal interaction between corium and coolants

    Zagorul'ko, Yu. I.; Zhmurin, V. G.; Volov, A. N.; Kovalev, Yu. P.

    2008-03-01

    We present a generalized analysis of the experimental results from investigations of thermal interaction in corium simulators (melts of thermite mixtures U + Mo3 and Zr + Fe2O3)-coolant (Na and H2O) systems. We also present the results from experimental assessments of the kinematic characteristics pertinent to the displacement of materials during the thermal interaction process and the coefficients for conversion of the corium thermal energy into mechanical work.

  15. Requirements for Real-Time Laboratory Experimentation over the Internet.

    Salzmann, C.; Latchman, H. A.; Gillet, D.; Crisalle, O. D.

    A prototype system based on an inverted pendulum is used to study the Quality of Service and discuss requirements of remote-experimentation systems utilized for carrying out control engineering experiments over the Internet. This class of applications involves the transmission over the network of a variety of data types with their own peculiar…

  16. Experimental Methods in Neuroscience: An Undergraduate Neuroscience Laboratory Course for Teaching Ethical Issues, Laboratory Techniques, Experimental Design, and Analysis

    Hall, Adam C.; Harrington, Mary E.

    2003-01-01

    We have developed and recently taught a 200 level undergraduate course entitled, ‘Experimental Methods in Neuroscience’. This is a required course in an increasingly popular Neuroscience major at Smith College. Students are introduced initially to issues of animal ethics and experimentation, and are familiarized with our Animal Care Facility. Using an open field and rotarod apparatus, and the elevated plus and Barnes mazes, they conduct behavioral testing of two strains of mice, C57/BL/6J and...

  17. Oak Ridge National Laboratory Research Reactor Experimenters' Guide

    The Oak Ridge National Laboratory has three multipurpose research reactors which accommodate testing loops, target irradiations, and beam-type experiments. Since the experiments must share common or similar facilities and utilities, be designed and fabricated by the same groups, and meet the same safety criteria, certain standards for these have been developed. These standards deal only with those properties from which safety and economy of time and money can be maximized and do not relate to the intent of the experiment or quality of the data obtained. The necessity for, and the limitations of, the standards are discussed; and a compilation of general standards is included

  18. EXPERIMENTAL INVESTIGATION OF AN AIR CHARGED LOW POWERED STIRLING ENGINE

    Can ÇINAR

    2004-01-01

    Full Text Available In this study, an air charged, low powered manufactured ? type Stirling engine was investigated experimentally. Tests were conducted at 800, 900 and 1000 °C hot source temperatures, 1, 1.5, 2, 2.5, 3, 3.5 bars air charge pressure. The variation of engine power depending on the charge pressure and hot source temperature for two different heat transfer area was investigated experimentally. Maximum output power was obtained at 1000 °C and 3 bars charge pressure as 58 W at 441 rpm. Engine speed was reached at 846 rpm without load.

  19. EXPERIMENTAL INVESTIGATION OF AN AIR CHARGED LOW POWERED STIRLING ENGINE

    Can ÇINAR

    2004-01-01

    In this study, an air charged, low powered manufactured ? type Stirling engine was investigated experimentally. Tests were conducted at 800, 900 and 1000 °C hot source temperatures, 1, 1.5, 2, 2.5, 3, 3.5 bars air charge pressure. The variation of engine power depending on the charge pressure and hot source temperature for two different heat transfer area was investigated experimentally. Maximum output power was obtained at 1000 °C and 3 bars charge pressure as 58 W at 441 rpm. Engine speed w...

  20. New experimental tools for bioassays with whitefly in laboratory

    Thiago Luis Martins Fanela

    2012-12-01

    Full Text Available The objective of this work was to develop an experimental kit for assessments of repellency, deterrence for oviposition, and insecticidal activity on adults of the whitefly Bemisia tabaci biotype B. The kit, which consisted of arenas and nebulizer, was effective for conducting bioassays, and the application of aqueous extracts by inhaler was adequate. The techniques are simple, cheap, and may contribute to research on this insect.

  1. EXPERIMENTAL INVESTIGATION OF CAVITATION IN A SUDDEN EXPANSION PIPE

    ZHANG Jian-min; YANG Qing; WANG Yu-rong; XU Wei-lin; CHEN Jian-gang

    2011-01-01

    For sudden expansion pipes, experiments were carried out to study the cavitation inception for various enlargement ratios in high speed flows.The flow velocity of the prototype reaches 50 m/s in laboratory.The relationship between the expansion ratio and the incipient cavitation number is obtained.The scale and velocity effects are revealed.It is shown that Keller's revised formula should be modified to calculate the incipient cavitation number when the forecasted velocity of the flows in the prototype exceeds the experimental velocity.

  2. An open microcomputer-based laboratory system for perceptional experimentality

    Hamalainen, Ari

    A computer, equipped with hardware for acquiring data about the properties of a physical system and programs for processing that data, is a powerful tool for physics research and instruction. There is strong evidence that utilizing microcomputer-based laboratories (MBLs) in instruction can lead to significantly improved learning. The perceptional approach is a method for physics instruction, developed at the Department of Physics, University of Helsinki. Its main arguments are that the meanings of the concepts must be learnt before their formal definitions and adoption, and that learning and research are fundamentally similar concept formation processes. Applying the perceptional approach requires the ability to perform quantitative experiments, either as students' laboratory exercises or as lecture demonstrations, and to process their results. MBL tools are essential for this. In student's laboratory exercises, they reduce the routine work and leave more time for the actual learning. In lecture demonstrations, they make it possible to perform the experiments in the tight time limits. At a previous stage of the research, a set of requirements was found that the perceptional approach places on MBL systems. The primary goal of this thesis is to build a prototype of a MBL system that would fulfil these requirements. A secondary goal is to describe technical aspects of a computerized measurement system from the standpoint of educational use. The prototype was built using mostly commercial sensors and data acquisition units. The software was written with a visual programming language, designed for instrumentation applications. The prototype system was developed and tested with a set of demonstrations of various topics in the Finnish high school physics curriculum, which were implemented according to the perceptional approach. Limited usability tests were also performed. The prototype was improved, until it could perform the test demonstrations. It was found to meet the

  3. Experimental investigations of overvoltages in neutral isolated networks

    Vukelja, P.I.; Naumov, R.M.; Vucinic, M.M.; Budisin, P.B. (Electrotechnicki Inst. ' Nikola Tesla' , Belgrade (Yugoslavia))

    1993-09-01

    For more than a decade, the Nikola Tesla Institute has worked intensively on experimental investigations of transient voltages and currents in neutral isolated networks, usually at 6 kV. The paper presents the results of investigations of overvoltages at the instant of appearance of an earth fault and during its interruption, the earth-fault currents and overvoltages during ferroresonance. Investigations were performed on cable station service networks in hydro- and thermal-power plants, industrial and similar installations in Yugoslavia. On the basis of these investigations, some measures are suggested for improving the reliability of operation of neutral isolated networks. (author)

  4. Laboratory investigation of axisymmetric single vacuum well point

    VU Van-tuan; YAO Lei-hua; WEI Ying-jie

    2016-01-01

    Vacuum well point is a new but faint soft ground treatment method. This work focuses on the consolidation behavior of a reconstituted soft clayey specimen under vacuum well point combined with surcharge loading. The laboratory test was conducted through a vacuum-surcharge consolidation apparatus, and the vacuum loading scheme was adopted for vacuum pressure application to investigate the vacuum effect on soil consolidation. In the testing process, some key parameters such as vacuum pressure, pore water pressure and settlement deformation were timely recorded. Furthermore, the water content, void ratio and permeability coefficient of samples collected after loading were measured to reflect the consolidation characteristics. By comparing with the membrane system and membraneless system, something different was found for the vacuum well point method. The results indicate that the consolidation behavior of an axisymmetric single vacuum well point is almost identical to the behavior of vacuum preloading combined with prefabricated vertical drain (PVD), except for the distribution of the vacuum pressure along the well drain due to the structure of the vacuum well point. And the vacuum well point method may be useful for the improvement of soft clayey deposit in a certain depth.

  5. An investigation into stent expansion using numerical and experimental techniques

    Toner, Deborah

    2009-01-01

    Extensive finite element analyses have been carried out by researchers to investigate the difference in the mechanical loading induced in vessels stented with various different stent designs and the influence of this loading on restenosis outcome. This study investigates the experimental validation of these numerical stent expansions using compliant mock arteries. The development of this in-vitro validation test has the prospect of providing a fully validated preclinical testing tool which ca...

  6. An Experimental Investigation of Secure Communication With Chaos Masking

    Dhar, Sourav

    2007-01-01

    The most exciting recent development in nonlinear dynamics is realization that chaos can be useful. One application involves "Secure Communication". Two piecewise linear systems with switching nonlinearities have been taken as chaos generators. In the present work the phenomenon of secure communication with chaos masking has been investigated experimentally. In this investigation chaos which is generated from two chaos generators is masked with the massage signal to be transmitted, thus makes communication is more secure.

  7. Numerical and experimental investigation of bump foil mechanical behaviour

    Larsen, Jon Steffen; Cerda Varela, Alejandro Javier; Santos, Ilmar

    2014-01-01

    Corrugated foils are utilized in air foil bearings to introduce compliance and damping thus accurate mathematical predictions are important. A corrugated foil behaviour is investigated experimentally as well as theoretically. The experimental investigation is performed by compressing the foil......, between two parallel surfaces, both statically and dynamically to obtain hysteresis curves. The theoretical analysis is based on a two dimensional quasi static FE model, including geometrical non-linearities and Coulomb friction in the contact points and neglects the foil mass. A method for implementing...... the friction is suggested. Hysteresis curves obtained via the FE model are compared to the experimental results obtained. Good agreement is observed in the low frequency range and discrepancies for higher frequencies are thoroughly discussed....

  8. Experimental Investigation of the Wind Turbine Blade Root Flow

    Akay, B.; Ferreira, C.S.; Van Bussel, G.J.W.

    2010-01-01

    Several methods from experimental to analytical are used to investigate the aerodynamics of a horizontal axis wind turbine. To understand 3D and rotational effects at the root region of a wind turbine blade, correct modeling of the flow field is essential. Aerodynamic models need to be validated by

  9. Choice of experimental venue matters in ecotoxicology studies: Comparison of a laboratory-based and an outdoor mesocosm experiment.

    Mikó, Zsanett; Ujszegi, János; Gál, Zoltán; Imrei, Zoltán; Hettyey, Attila

    2015-10-01

    The heavy application of pesticides and its potential effects on natural communities has attracted increasing attention to inadvertent impacts of these chemicals. Toxicologists conventionally use laboratory-based tests to assess lethal concentrations of pesticides. However, these tests often do not take into account indirect, interactive and long-term effects, and tend to ignore different rates of disintegration in the laboratory and under natural conditions. Our aim was to investigate the importance of the experimental venue for ecotoxicology tests. We reared tadpoles of the agile frog (Rana dalmatina) in the laboratory and in outdoor mesocosms and exposed them to three initial concentrations of a glyphosate-based herbicide (0, 2 and 6.5 mg a.e./L glyphosate), and to the presence or absence of caged predators (dragonfly larvae). The type of experimental venue had a large effect on the outcome: The herbicide was less lethal to tadpoles reared in outdoor mesocosms than in the laboratory. Further, while the herbicide had a negative effect on development time and on body mass in the laboratory, tadpoles exposed to the herbicide in mesocosms were larger at metamorphosis and developed faster in comparison to those reared in the absence of the herbicide. The effect of the herbicide on morphological traits of tadpoles also differed between the two venues. Finally, in the presence of the herbicide, tadpoles tended to be more active and to stay closer to the bottom of laboratory containers, while tadpole behaviour shifted in the opposite direction in outdoor mesocosms. Our results demonstrate major discrepancies between results of a classic laboratory-based ecotoxicity test and outcomes of an experiment performed in outdoor mesocosms. Consequently, the use of standard laboratory tests may have to be reconsidered and their benefits carefully weighed against the difficulties of performing experiments under more natural conditions. Tests validating experimentally estimated

  10. Experimental and numerical investigation on two-phase flow instabilities

    Ruspini, Leonardo Carlos

    2013-03-01

    Two-phase flow instabilities are experimentally and numerically studied within this thesis. In particular, the phenomena called Ledinegg instability, density wave oscillations and pressure drop oscillations are investigated. The most important investigations regarding the occurrence of two-phase flow instabilities are reviewed. An extensive description of the main contributions in the experimental and analytical research is presented. In addition, a critical discussion and recommendations for future investigations are presented. A numerical framework using a hp-adaptive method is developed in order to solve the conservation equations modelling general thermo-hydraulic systems. A natural convection problem is analysed numerically in order to test the numerical solver. Moreover, the description of an adaptive strategy to solve thermo-hydraulic problems is presented. In the second part of this dissertation, a homogeneous model is used to study Ledinegg, density wave and pressure drop oscillations phenomena numerically. The dynamic characteristics of the Ledinegg (flow excursion) phenomenon are analysed through the simulation of several transient examples. In addition, density wave instabilities in boiling and condensing systems are investigated. The effects of several parameters, such as the fluid inertia and compressibility volumes, on the stability limits of Ledinegg and density wave instabilities are studied, showing a strong influence of these parameters. Moreover, the phenomenon called pressure drop oscillations is numerically investigated. A discussion of the physical representation of several models is presented with reference to the obtained numerical results. Finally, the influence of different parameters on these phenomena is analysed. In the last part, an experimental investigation of these phenomena is presented. The designing methodology used for the construction of the experimental facility is described. Several simulations and a non

  11. The role of laboratory investigations in evaluating abdominal tuberculosis

    Sherwani Rana

    2015-01-01

    Full Text Available Background and Objectives: Tuberculosis (TB continues to be a major health problem in developing countries like India. Abdominal TB is defined as an infection of the peritoneum, or hollow or solid abdominal organs with Mycobacterium tuberculosis (Mtb. The gastrointestinal tract is one of the most frequent sites of extrapulmonary involvement in TB. The present study was undertaken to evaluate the role of laboratory investigations in the diagnosis of abdominal TB. Materials and Methods: The study was conducted on 300 patients admitted to various departments of our hospital from November 2005 to October 2007. Detailed histories and thorough clinical examinations together with relevant hematological, biochemical, cytological, radiological, and histopathological investigations were carried out in suspected cases of Koch′s abdomen. Results: Erythrocyte sedimentation rates with positive results were seen in 79.3% patients. Serological test enzyme-linked immunosorbent assay was performed on only 30 patients and was found to be positive for IgG, and IgM in 25 cases with a sensitivity of 83%. Thirteen out of 15 cases were positive for adenosine deaminase done on ascitic fluid. The results of the two patients who underwent Mtb polymerase chain reaction (PCR were consistent with TB. Out of 21 image-guided fine-needle aspiration cytology (FNAC cases, 10 (48% of the positive cases showed caseating necrosis while 7 (33% had noncaseous necrosis. Stain for acid-fast bacilli (AFB was performed on all cases and was positive in 42 cases (38.8%. Lymph node biopsy was done in 95% of the cases. Conclusions: Serological investigations have a limited value, while PCR is a highly specific test. Since cost restricts its use, only two patients in our study could afford it. BACTEC is more sensitive and faster than culture techniques for the diagnosis of mycobacterial infections. FNAC is a reliable, cost effective alternative, and 81% diagnostic yield in the present study

  12. Laboratory investigation of antenna signals from dust impacts on spacecraft

    Sternovsky, Zoltan; Collette, Andrew; Malaspina, David M.; Thayer, Frederick

    2016-04-01

    Electric field and plasma wave instruments act as dust detectors picking up voltage pulses induced by impacts of particulates on the spacecraft body. These signals enable the characterization of cosmic dust environments even with missions without dedicated dust instruments. For example, the Voyager 1 and 2 spacecraft performed the first detection of dust particles near Uranus, Neptune, and in the outer solar system [Gurnett et al., 1987, 1991, 1997]. The two STEREO spacecraft observed distinct signals at high rate that were interpreted as nano-sized particles originating from near the Sun and accelerated to high velocities by the solar wind [MeyerVernet et al, 2009a, Zaslavsky et al., 2012]. The MAVEN spacecraft is using the antennas onboard to characterize the dust environment of Mars [Andersson et al., 2014] and Solar Probe Plus will do the same in the inner heliosphere. The challenge, however, is the correct interpretation of the impact signals and calculating the mass of the dust particles. The uncertainties result from the incomplete understanding of the signal pickup mechanisms, and the variation of the signal amplitude with impact location, the ambient plasma environment, and impact speed. A comprehensive laboratory study of impact generated antenna signals has been performed recently using the IMPACT dust accelerator facility operated at the University of Colorado. Dust particles of micron and submicron sizes with velocities of tens of km/s are generated using a 3 MV electrostatic analyzer. A scaled down model spacecraft is exposed to the dust impacts and one or more antennas, connected to sensitive electronics, are used to detect the impact signals. The measurements showed that there are three clearly distinct signal pickup mechanisms due to spacecraft charging, antenna charging and antenna pickup sensing space charge from the expanding plasma cloud. All mechanisms vary with the spacecraft and antenna bias voltages and, furthermore, the latter two

  13. Investigation of high purity beryllium for the International Thermonuclear Experimental Reactor (ITER), Task 002. Final report

    The report includes a description of experimental abilities of Solid Structure Research Laboratory of IAE NNC RK, a results of microstructural characterization of A-4 grade polycrystal Beryllium produced at the Ulba metal plant and a technical project-for irradiation experiments. Technical project contains a detailed description of five proposed experiments, clearing behavior of Beryllium materials under the influence of irradiation, temperature, helium and hydrogen accumulation. Complex irradiation jobs, microstructural investigations and mechanical tests are planned in the framework of these experiments

  14. Integrating Laboratory and Numerical Decompression Experiments to Investigate Fluid Dynamics into the Conduit

    Spina, Laura; Colucci, Simone; De'Michieli Vitturi, Mattia; Scheu, Bettina; Dingwell, Donald Bruce

    2015-04-01

    The study of the fluid dynamics of magmatic melts into the conduit, where direct observations are unattainable, was proven to be strongly enhanced by multiparametric approaches. Among them, the coupling of numerical modeling with laboratory experiments represents a fundamental tool of investigation. Indeed, the experimental approach provide invaluable data to validate complex multiphase codes. We performed decompression experiments in a shock tube system, using pure silicon oil as a proxy for the basaltic melt. A range of viscosity comprised between 1 and 1000 Pa s was investigated. The samples were saturated with Argon for 72h at 10MPa, before being slowly decompressed to atmospheric pressure. The evolution of the analogue magmatic system was monitored through a high speed camera and pressure sensors, located into the analogue conduit. The experimental decompressions have then been reproduced numerically using a multiphase solver based on OpenFOAM framework. The original compressible multiphase Openfoam solver twoPhaseEulerFoam was extended to take into account the multicomponent nature of the fluid mixtures (liquid and gas) and the phase transition. According to the experimental conditions, the simulations were run with values of fluid viscosity ranging from 1 to 1000 Pa s. The sensitivity of the model has been tested for different values of the parameters t and D, representing respectively the relaxation time for gas exsolution and the average bubble diameter, required by the Gidaspow drag model. Valuable range of values for both parameters are provided from experimental observations, i.e. bubble nucleation time and bubble size distribution at a given pressure. The comparison of video images with the outcomes of the numerical models was performed by tracking the evolution of the gas volume fraction through time. Therefore, we were able to calibrate the parameter of the model by laboratory results, and to track the fluid dynamics of experimental decompression.

  15. Experimental investigation on the natural convection flow in pool boiling

    Kim, Seok, E-mail: seokim@kaeri.re.kr [Thermal Hydraulics Safety Research Division, Korea Atomic Energy Research Institute, 111 Daedeok-daero989beongil, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Kim, Dong Eok [Department of Precision Mechanical Engineering, Kyungpook National University, 386 Gajang-dong, Sangju, Gyeongsangbuk-do 742-711 (Korea, Republic of); Ryu, Sung Uk; Lee, Seung Tae; Euh, Dong-Jin [Thermal Hydraulics Safety Research Division, Korea Atomic Energy Research Institute, 111 Daedeok-daero989beongil, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2014-12-15

    Highlights: • The velocity field measurements conducted on the subject of a single and two-phase natural convection flow. • Experimental results show a large natural convection flow at the region above the heater rod. • The thermal stratification is shown at the region below the heater rod. • The results contribute to provide the benchmark data of a thermal hydraulic system analysis code. - Abstract: In the present study, the key thermal hydraulic phenomena within a passive condensate cooling tank (PCCT) of a small-scale pool test rig with a single heater rod are experimentally investigated. The volumetric scaling ratio of the test rig is 1/910 the size of the passive auxiliary feedwater system (PAFS) condensing heat removal assessment loop (PASCAL), which is a PAFS performance evaluation test facility. The two-dimensional velocity vector fields that occur as the water level decreases are experimentally investigated in a pool that contains a horizontal heater rod. The 2D particle image velocimetry (PIV) measurement technique is adopted to determine the velocity vector field of the natural convection flow. The experimental results indicate that a large natural convection flow occurs above the heater rod and that thermal stratification occurs below the heater rod. The thermal stratification and the stagnant region begin to disappear when the pool temperature reaches approximately 90 °C. The experimental results can provide benchmark data to validate computational fluid dynamics (CFD) calculations of thermal hydraulic phenomena that occur in a pool with a heat source.

  16. Laboratory investigation of crushed salt consolidation and fracture healing

    A laboratory test program was conducted to investigate the consolidation behavior of crushed salt and fracture healing in natural and artificial salt. Crushed salt is proposed for use as backfill in a nuclear waste repository in salt. Artificial block salt is proposed for use in sealing a repository. Four consolidation tests were conducted in a hydrostatic pressure vessel at a maximum pressure of 2500 psi (17.2 MPa) and at room temperature. Three 1-month tests were conducted on salt obtained from the Waste Isolation Pilot Plant and one 2-month test was conducted on salt from Avery Island. Permeability was obtained using argon and either a steady-state or transient method. Initial porosities ranged from 0.26 to 0.36 and initial permeabilities from 2000 to 50,000 md. Final porosities and permeabilities ranged from 0.05 to 0.19 and from -5 md to 110 md, respectively. The lowest final porosity (0.05) and permeability (-5 md) were obtained in a 1-month test in which 2.3% moisture was added to the salt at the beginning of the test. The consolidation rate was much more rapid than in any of the dry salt tests. The fracture healing program included 20 permeability tests conducted on fractured and unfractured samples. The tests were conducted in a Hoek cell at hydrostatic pressures up to 3000 psi (20.6 MPa) with durations up to 8 days. For the natural rock salt tested, permeability was strongly dependent on confining pressure and time. The effect of confining pressure was much weaker in the artificial salt. In most cases the combined effects of time and pressure were to reduce the permeability of fractured samples to the same order of magnitude (or less) as the permeability measured prior to fracturing

  17. Laboratory investigation of crushed salt consolidation and fracture healing

    1987-01-01

    A laboratory test program was conducted to investigate the consolidation behavior of crushed salt and fracture healing in natural and artificial salt. Crushed salt is proposed for use as backfill in a nuclear waste repository in salt. Artificial block salt is proposed for use in sealing a repository. Four consolidation tests were conducted in a hydrostatic pressure vessel at a maximum pressure of 2500 psi (17.2 MPa) and at room temperature. Three 1-month tests were conducted on salt obtained from the Waste Isolation Pilot Plant and one 2-month test was conducted on salt from Avery Island. Permeability was obtained using argon and either a steady-state or transient method. Initial porosities ranged from 0.26 to 0.36 and initial permeabilities from 2000 to 50,000 md. Final porosities and permeabilities ranged from 0.05 to 0.19 and from <10/sup -5/ md to 110 md, respectively. The lowest final porosity (0.05) and permeability (<10/sup -5/ md) were obtained in a 1-month test in which 2.3% moisture was added to the salt at the beginning of the test. The consolidation rate was much more rapid than in any of the dry salt tests. The fracture healing program included 20 permeability tests conducted on fractured and unfractured samples. The tests were conducted in a Hoek cell at hydrostatic pressures up to 3000 psi (20.6 MPa) with durations up to 8 days. For the natural rock salt tested, permeability was strongly dependent on confining pressure and time. The effect of confining pressure was much weaker in the artificial salt. In most cases the combined effects of time and pressure were to reduce the permeability of fractured samples to the same order of magnitude (or less) as the permeability measured prior to fracturing.

  18. METHODS OF EXPERIMENTAL VERIFICATION OF STEINER THEOREM IN PHYSICAL PRACTICUM AND LABORATORY WORK

    Zharilkasin Iskakov

    2014-07-01

    Full Text Available In this paper, the technique of laboratory work on experimental verification of Steiner’s Theorem in laboratory conditions is developed. To do this, specially designed experimental device was used. The main part of such device is a simple physical pendulum, swinging freely about the axis of suspension, consisting of a cylindrical disc set on a thin rod. To determine the moment of inertia of cylindrical body about the axis of vibrations, property of a physical quantity additivity was used. When processing experimental results, functional approximation by a least squares method was applied; as a result, the empirical expression of Steiner’s Theorem was achieved. Results of experimental studies were very close to the results of theoretical calculations. Laboratory work can be easily repeated for a body of arbitrary shape. The methodology used can be recommended for physical practicum in universities as an effective and easy way of experimental verification of Steiner’s theorem.

  19. Field and Laboratory Investigations of Organic Photochemistry on Urban Surfaces

    Styler, S. A.; Baergen, A.; van Pinxteren, D.; Donaldson, D. J.; Herrmann, H.

    2014-12-01

    In polluted urban environments, windows and building surfaces rapidly become coated with a complex film of chemicals, which enhances the dry deposition of particles and the partitioning of semi-volatile organic species to the surface. Despite its high surface-to-volume ratio and direct exposure to sunlight, few studies have directly investigated the role that this "urban film" may play in promoting the photooxidative processing of semi-volatile organics contained within it. The present study represents a comprehensive field- and laboratory-based investigation of the film-phase photochemistry of polycyclic aromatic hydrocarbons (PAH), here used as proxies for light-absorbing semi-volatile organics present within the film. Urban film sampling was conducted using a custom-built three-stage sampler housing, which was deployed in a central, high-traffic area in Leipzig, Germany. The sampler itself employs small glass beads as surrogate window surfaces and is designed such that only its uppermost stage is exposed to sunlight. Each stage is subdivided into 16 compartments, which allows for the study of film formation and evolution. In the first phase of the study, the role of urban film as a photochemical sink for reactive organic species was determined by measuring total film PAH content and PAH abundance ratios as a function of atmospheric exposure time under both light and dark conditions. In the second, more general, phase of the study, the organic and inorganic composition of collected film samples was compared to that of co-located PM10 samples, and differences between the two sample types were used to gain insight into the relative importance of heterogeneous photochemical oxidation within the particle and film phases. In the third phase of the study, film samples grown under dark conditions were exposed to gas-phase ozone in an atmospheric-pressure flat-bed reactor, and the kinetics of ozone-induced PAH loss were studied under both dark and illuminated conditions

  20. Experimental investigations on dynamic effects in impact notch bending tests

    The dynamic behaviour of three point bending samples under impact stresses is examined experimentally. Various measuring processes, above all the shadow optics etching process are used. A quasi-static analysis is made by a simple spring/mass model to describe the stress behaviour quantitatively. Based on this, the dynamic effects in model experiments are measured quantitatively with dynamic correction functions and are discussed with reference to the wave processes in the sample. A systematic view of the effect of the many system parameters on the dynamic stress behaviour is obtained. Finally, examples show that the results of this model investigation can be transferred to other experimental conditions. (orig./HP)

  1. Experimental Investigation of Effect on Hydrate Formation in Spray Reactor

    Jianzhong Zhao

    2015-01-01

    Full Text Available The effects of reaction condition on hydrate formation were conducted in spray reactor. The temperature, pressure, and gas volume of reaction on hydrate formation were measured in pure water and SDS solutions at different temperature and pressure with a high-pressure experimental rig for hydrate formation. The experimental data and result reveal that additives could improve the hydrate formation rate and gas storage capacity. Temperature and pressure can restrict the hydrate formation. Lower temperature and higher pressure can promote hydrate formation, but they can increase production cost. So these factors should be considered synthetically. The investigation will promote the advance of gas storage technology in hydrates.

  2. Investigating Electromagnetic Induction through a Microcomputer-Based Laboratory.

    Trumper, Ricardo; Gelbman, Moshe

    2000-01-01

    Describes a microcomputer-based laboratory experiment designed for high school students that very accurately analyzes Faraday's law of electromagnetic induction, addressing each variable separately while the others are kept constant. (Author/CCM)

  3. The hot cell laboratories for material investigations of the Institute for Safety Research

    Viehrig, H.W.

    1998-10-01

    Special facilities for handling and testing of irradiated specimens are necessary, to perform the investigation of activated material. The Institute for Safety Research has two hot cell laboratories: - the preparation laboratory and - the materials testing laboratory. This report is intended to give an overview of the available facilities and developed techniques in the laboratories. (orig.)

  4. Experimental techniques for the investigation of coupled phenomena in geomaterials

    Romero E.

    2010-06-01

    Full Text Available The paper describes different experimental setups and techniques used to investigate coupled stress, fluid (water and air and temperature effects on geomaterials. Two temperature controlled cells are described: a a constant volume cell in which thermal pulses can be performed under controlled hydraulic conditions to induce pore pressure build-up during quasi-undrained heating and later dissipation; and b an axisymmetric triaxial cell with controlled suction and temperature to perform drained heating and cooling paths under partially saturated states. The paper also presents an experimental setup to perform controlled flow-rate gas injection experiments on argillaceous rocks using a high-pressure triaxial cell. This cell is used to study gas migration phenomena and the conditions under which gas breakthrough processes occur. Selected test results are presented, which show the capabilities of the different experimental setups described to capture main behavioural features.

  5. Experimental and numerical investigation on an innovative solar chimney

    Highlights: • Intensifiers were applied to increase heat flux. • Numerical and experimental data were compered. • We investigated the rotational pattern of the air inside the SC. • This chimney is equipped with a container, placed exactly beneath the collector. - Abstract: A novel small scale model of solar chimney was investigated experimentally and numerically. Air flow, heat transfer and flow characteristics were numerically calculated and compared with the experimental results in this paper. Two intensifiers were used to intensify the heat flux radiated by the sun all around the solar chimney in the experimental case. An air tank was located downside the system to increase the absorption of the solar radiation reflected by the intensifiers. RNG k–ε model was chosen to simulate the turbulence and the well-known SIMPLE algorithm was used to solve the coupled velocity and pressure equations. Results show that utilization of intensifiers caused an increase in velocity magnitude in the chimney and consequently more power was generated. The maximum velocity of 5.12 m/s was reached which is remarkable, considering the small size of the SC structure

  6. Experimental and theoretical investigation of high gradient acceleration

    This report contains a technical progress summary of the research conducted under the auspices of DOE Grant No. DE-AC02-91-ER40648, ''Experimental and Theoretical Investigations of High Gradient Acceleration''. This grant supports three research tasks: Task A consists of the design, fabrication and testing of a 17GHz RF photocathode gun, which can produce 2ps electron pulses with up to 1nC of charge at 2MeV energy and at a 1OHz repetition rate. Task B supports the testing of high gradient acceleration at 33GHz structure, and Task C comprises theoretical investigations, both in support of the experimental tasks and on critical physics issues for the development of high energy linear colliders

  7. Experimental and theoretical investigation of high gradient acceleration

    This report contains a technical progress summary of the research conducted under the auspices of DOE Grant No. DE-FG0291ER-40648. ''Experimental and Theoretical Investigations of High Gradient Acceleration.'' This grant supports three research tasks: Task A consists of the design and fabrication of a 17GHz of photocathode gun, Task B supports the testing of high gradient acceleration using a 33GHz structure, and Task C comprises theoretical investigations, both in support of the experimental tasks and on critical physics issues for the development of high energy linear colliders. This report is organized as follows. The development of an rf gun design and research progress on the picosecond laser system is summarized in Sec. 2, the status of the studies of the LBL/Haimson high gradient structure, using a 50 MW free-electron laser is summarized in Sec. 3, and theoretical research progress is described in Sec. 4. Supporting material is contained in Appendices A-G

  8. COMPARATIVE FIELD EXPERIMENTAL INVESTIGATIONS OF DIFFERENT FLAT PLATE SOLAR COLLECTORS

    Guangming Chen

    2015-12-01

    Full Text Available Full-scale traditional metal solar collectors and solar collector specimens fabricated from polymeric materials were investigated in the present study. A polymeric collector is 67.8% lighter than a traditional metal solar collector, and a metal solar collector with transparent plastic covering is 40.3% lighter than a traditional metal solar collector. Honeycomb multichannel plates made from polycarbonate were chosen to create a polymeric solar collector. A test rig for the natural circulation of the working fluid in a solar collector was built for a comparative experimental investigation of various solar collectors operating at ambient conditions. It was shown experimentally that the efficiency of a polymeric collector is 8–15% lower than the efficiency of a traditional collector.

  9. Experimental and theoretical investigation of high gradient acceleration

    Wurtele, J.S.; Bekefi, G.; Chen, C.; Chen, S.C.; Temkin, R.J.

    1993-01-01

    This report contains a technical progress summary of the research conducted under the auspices of DOE Grant No. DE-AC02-91-ER40648, Experimental and Theoretical Investigations of High Gradient Acceleration''. This grant supports three research tasks: Task A consists of the design, fabrication and testing of a 17GHz RF photocathode gun, which can produce 2ps electron pulses with up to 1nC of charge at 2MeV energy and at a 1OHz repetition rate. Task B supports the testing of high gradient acceleration at 33GHz structure, and Task C comprises theoretical investigations, both in support of the experimental tasks and on critical physics issues for the development of high energy linear colliders.

  10. Experimental and numerical investigation of thermal flow meter

    Cebula Artur

    2015-01-01

    The paper presents analytical and numerical model calculation results of the temperature distribution along the thermal flow meter. Results show a very good conformity between numerical and analytical model. Apart from the calculation results the experimental investigations are presented. The author performed the test where a temperature of duct wall surface was measured. The relation between mass flow rate in terms of the duct surface temperature difference was developed.

  11. An experimental method for coating-substrate interface investigation

    Wänstrand, Olle; Podgornik, Bojan

    2015-01-01

    Investigations of coated surfaces indicate that in many cases the coating-substrate interface is the weakest part of the coated component, with the coating-to-substrate adhesion being used to evaluate the strength of the coating-substrate interface. While modeling of the coated surface depends on coating and substrate material properties, which are not easy to determine, standard experimental methods do not allow a direct study of the interface. The aim of the present paper is to describe a s...

  12. Experimental investigation of the serum albumin fascia microstructure

    Buzoverya, M. E.; Shcherbak, Yu. P.; Shishpor, I. V.

    2012-09-01

    The results of theoretical and experimental investigation of biological liquids are reported. Structural effects observed in fascias are considered with account of the molecular features of albumin and the concept of supramolecular organization of polymers. It is revealed that the morphology of human serum albumin fascias depends on the concentration and quality of the solvent. It is shown that the water-salt fascias of albumin are more structured than water solutions with the same concentration.

  13. An Experimental Investigation on Inclined Negatively Buoyant Jets

    Bashitialshaaer, Raed; Larson, Magnus; Persson, Kenneth M.

    2012-01-01

    An experimental study was performed to investigate the behavior of inclined negatively buoyant jets. Such jets arise when brine is discharged from desalination plants. A turbulent jet with a specific salinity was discharged through a circular nozzle at an angle to the horizontal into a tank with fresh water and the spatial evolution of the jet was recorded. Four different initial jet parameters were changed, namely the nozzle diameter, the initial jet inclination, the jet density and the flow...

  14. Experimental and numerical investigations on adhesively bonded joints

    Negru, R.; Marsavina, L.; Hluscu, M.

    2016-04-01

    Two types of adhesively bonded joints were experimental and numerical investigated. Firstly, the adhesives were characterized through a set of tests and the main elastic and mechanical properties were obtained. After that, the stress distributions at interface and middle of adhesive layer were determined using a linear elastic FEA. The numerical data were fitted by a power law in order to determine the critical values of intensity of stress singularity.

  15. Characteristics of Constrained Handwritten Signatures: An Experimental Investigation

    Donato, Impedovo; Pirlo, Giuseppe; Rizzi, Fabrizio

    2015-01-01

    Handwritten signatures are considered one of the most useful biometric traits for personal verification. In the networked society, in which a multitude of different devices can be used for signature acquisition, specific research is still needed to determine the extent to which features of an input signature depend on the characteristics of the signature apposition process. In this paper an experimental investigation was carried out on constrained signatures, which were acquired using writing...

  16. Experimental Investigation On Design Of High Pressure Steam Turbine Blade

    SUBRAMANYAM PAVULURI, DR. A. SIVA KUMAR

    2013-01-01

    The Experimental investigation on design of high pressure steam turbine blade addresses the issue of steam turbine efficiency. A specific focus on aerofoil profile for high pressure turbine blade, and it evaluates the effectiveness of certain Chromium and Nickel in resisting creep and fracture in turbine blades. The capable of thermal and chemical conditions in blade substrate from to prevent the corrosion when exposed to wet steam. The efficiency of the steam turbine is a key factor in both ...

  17. Experimental Investigation of a W-Band Gyroklystron Amplifier

    Blank, Monica; Danly, Bruce; Levush, Baruch; Latham, Peter

    1997-05-01

    A four cavity W-band gyroklystron amplifier experiment is currently underway at the Naval Research laboratory. The gyroklystron has produced 55.5 kW peak output power and 23.5% efficiency in the TE_01 mode with a 56 kV, 4.2 A electron beam. The -3 dB bandwidth is greater than 400 MHz. The small signal and saturated gains are 36 dB and 28 dB, respectively. A time dependent version of the non-linear code MAGYKL (P.E. Latham, W. Lawson, V. Irwin, IEEE Trans. Plasma Sci., Vol. 22, No. 5, pp. 804-817, 1994.) was developed to design the interaction circuit. Theoretical performance predictions are in good agreement with experimental results. Details of the circuit design, comparisons of theory with measured data, and plans for future experiments will be presented.

  18. Experimental Investigation on Selective Laser Melting of Glass

    Fateri, Miranda; Gebhardt, Andreas; Thuemmler, Stefan; Thurn, Laura

    Although laser-based Additive Manufacturing (AM) processes have been investigated extensively for use with different materials, fabrication of 3D glass objects using Selective Laser Melting (SLM) technology is not well developed even though it has many applications. As such an experimental investigation on the process parameters of glass powder using SLM process was conducted and the results are summarized in this paper. Multiple 3D objects were fabricated and analyzed. Lastly Scanning Electron Microcopy (SEM) of the manufactured objects as well as effect of process parameters on dimensional accuracy, surface quality, and the density of the fabricated parts are presented in this paper.

  19. Experimental investigation on SPS casing treatment with bias flow

    Dong Xu

    2014-12-01

    Full Text Available Generally, casing treatment (CT is a passivity method to enhance the stall margin of fan/compressor. A novel casing treatment based on the small disturbance theory and vortex and wave interaction suggestion is a method combining passive control and active control, which has been proved effective at enhancing the stall margin of fan/compressor in experiment. In order to investigate the mechanism of this kind of casing treatment, an experimental investigation of a stall precursor-suppressed (SPS casing treatment with air suction or blowing air is conducted in the present paper. The SPS casing treatment is designed to suppressing stall precursors to realize stall margin enhancement in turbomachinery. The experimental results show that the casing treatment with blowing air of small quantity can improve the stall margin by about 8% with about 1% efficiency loss. By contrast, the SPS casing treatment with micro-bias flow does not improve the stall margin much more than that without bias flow, even worse. Meanwhile, the present investigation has also attempted to reveal the mechanism of stall margin improvement with the casing treatment. It is found that the stall margin improvements vary with the modification of the unsteady shedding flow and the unsteady wall boundary impedance. The experimental results agree fairly well with the theoretical prediction using a flow stability model of rotating stall.

  20. Experimental and numerical investigation of a draft tube cone at lower runner speeds

    Bosioc, Alin I.; Tanasa, Constantin

    2016-06-01

    The variable demand on the energy market enforces that hydraulic turbine to operate at different regimes, far from the best efficiency point. An experimental test rig was developed in our laboratory in order to reproduce these regimes. As a result, the investigated flow regimes allow us to quantify the flow behavior from part load operation to full load operation. The paper focuses on experimental and numerical investigations of mean velocity profiles and of stagnant region developed in the centre of draft tube cone. First the numerical results are validated against experimental results. At the end a qualitative analysis of the streamline pattern is complemented, giving us an evaluation of the stagnant region from the draft tube cone at different runner speeds.

  1. A Collaborative, Investigative Recombinant DNA Technology Course with Laboratory

    Pezzementi, Leo; Johnson, Joy F.

    2002-01-01

    A recombinant DNA technology course was designed to promote contextual, collaborative, inquiry-based learning of science where students learn from one another and have a sense of ownership of their education. The class stressed group presentations and critical reading and discussion of scientific articles. The laboratory consisted of two research…

  2. Ribose 5-Phosphate Isomerase Investigations for the Undergraduate Biochemistry Laboratory

    Jewett, Kathy; Sandwick, Roger K.

    2011-01-01

    The enzyme ribose 5-phosphate isomerase (RpiA) has many features that make it attractive as a focal point of a semester-long, advanced biochemistry laboratory for undergraduate students. The protein can easily and inexpensively be isolated from spinach using traditional purification techniques. Characterization of RpiA enzyme activity can be…

  3. Laboratory investigations of effective flow behavior in unsaturated heterogeneous sands

    Wildenschild, Dorthe; Høgh Jensen, Karsten

    1999-01-01

    controlled method. The heterogeneous sand systems were established in a laboratory tank for three realizations of random distributions of the homogeneous sands comprising a system of 207 grid cells. The water flux was controlled at the upper boundary, while a suction was applied at the lower boundary such...

  4. Experimental investigations on fiber laser color marking of steels

    Highlights: • We develop an experimental approach with the aim to bring a contribution to the comprehension of the occurring phenomena during laser color marking of steels. • We have used a home-made marking device composed of a pulsed fiber laser and galvanometric mirrors. • Both commercial and elaborated in laboratory steels have been used as samples. • The experiments have been performed for different laser beam operating parameters, under normal atmospheric conditions. • The treated samples were analyzed either by optical and scanning electronic microscopy, as well as by energy dispersion spectroscopy. - Abstract: We develop an experimental approach with the aim to bring a contribution to the comprehension of the occurring phenomena during laser color marking of steels. A home-made marking device using a pulsed fiber laser has been used to treat steel samples under different laser beam operating parameters, for different compositions of the processed steel, and at normal atmospheric conditions. The treated samples were analyzed either by optical and scanning electronic microscopy, as well as by energy dispersion spectroscopy. The results show the influence of the operating parameters on the obtained colors

  5. Assessment of experimental research techniques for the investigation of radionuclide migration in aquifers

    The objectives of this work have been to contribute to a better understanding of the transport behaviour of the actinides using Eu as a homologue and, in addition, to compare the different laboratory techniques used in migration studies - batch, column and diffusion tests. The experimental work was focused on the radioisotopes of (Na), (Ca), Sr, Zr, (Nb), Tc, Eu and (Pu) and investigated the essential influences on the transport behaviour, exerted by redox conditions, the formation of complexes with natural humic acid as well as the formation and/or presence of colloids. Samples from the Gorleben and Drigg sites were investigated

  6. Experimental Investigation of Optimal Adhesion of Mushroomlike Elastomer Microfibrillar Adhesives.

    Marvi, Hamidreza; Song, Sukho; Sitti, Metin

    2015-09-22

    Optimal fiber designs for the maximal pull-off force have been indispensable for increasing the attachment performance of recently introduced gecko-inspired reversible micro/nanofibrillar adhesives. There are several theoretical studies on such optimal designs; however, due to the lack of three-dimensional (3D) fabrication techniques that can fabricate such optimal designs in 3D, there have not been many experimental investigations on this challenge. In this study, we benefitted from recent advances in two-photon lithography techniques to fabricate mushroomlike polyurethane elastomer fibers with different aspect ratios of tip to stalk diameter (β) and tip wedge angles (θ) to investigate the effect of these two parameters on the pull-off force. We found similar trends to those predicted theoretically. We found that β has an impact on the slope of the force-displacement curve while both β and θ play a role in the stress distribution and crack propagation. We found that these effects are coupled and the optimal set of parameters also depends on the fiber material. This is the first experimental verification of such optimal designs proposed for mushroomlike microfibers. This experimental approach could be used to evaluate a wide range of complex microstructured adhesive designs suggested in the literature and optimize them. PMID:26322396

  7. Experimental investigation of interaction processes between droplets and hot walls

    Karl, A.; Frohn, A.

    2000-04-01

    A detailed experimental investigation of interaction processes of small liquid droplets with hot walls well above the Leidenfrost temperature has been carried out. The experimental method which uses monodisperse droplet streams in combination with a standard video camera allows very detailed observations and measurements with very high time resolution. The main intent of this paper is to study the mechanical behavior of liquid droplets impacting on hot walls well above the Leidenfrost temperature. A better understanding of this process may lead to a better modeling of two-phase flows, especially for applications in fuel preparation processes, combustion processes, and spray cooling. The loss of momentum of the droplets, the droplet deformation, and the onset of droplet disintegration have been investigated. For all experimental results correlations have been developed, which can be used to improve the numerical modeling of two-phase flows. Using the correlation for the loss of momentum a theoretical approximation for the maximum droplet deformation has been deduced, which yields a very good agreement with our own measurements as well as with results reported in the literature. A minimum impinging angle for droplet disintegration has been discovered for small impinging angles. Below this impinging angle no droplet disintegration is observed. This phenomenon is directly related to the energy dissipation at the wall during the interaction process. With the presented work the understanding of basic interaction processes between droplets and hot walls may be improved.

  8. Experimental Investigation of the Rayleigh-Taylor Instability

    White, Jeremy

    2011-12-01

    A series of experiments have been carried out to study the behavior of the Rayleigh-Taylor instability. The experiments cover a wide range of Atwood (A = (rho2-rho1)/(rho 2-rho1)) numbers, 0.28 ≤ A ≤ 1 using immiscible fluids, with Reynolds numbers spanning four orders of magnitude, ˜ 10 ≤ Re ≤ 10000. Multiple 2D interface shapes have been studied along with a single 3D configuration. The unique properties of magnetorheological fluids are exploited to generate well defined, static initial conditions for both single and multi-mode sinusoidal perturbations as well as isolated wavelengths of single-mode perturbations protruding from flat interfaces. The magnetic properties of the fluid are used to hold these shapes static prior to running, as well as to suspend them above a lighter fluid to allow gravity to provide acceleration to drive the mixing. The 2D experimental results corroborate some of the limitations of the non-linear analytical models, which have been recently investigated numerically, as well as observed in 3D experiments, but not reported in 2D experiments before. The unbounded growth of the Rayleigh-Taylor spikes at late times has been experimentally confirmed for both the 3D condition, where this is predicted to occur for all Atwood numbers, and for the A = 1 limit in the 2D configuration. Preliminary testing with multi-mode interface shapes with high viscosity, high surface tension MR fluids demonstrate the feasibility of extending this unique experimental technique to the more complicated multi-mode/broadband initial conditions more commonly present in applications. Further extension to lower viscosity and surface tension MR fluids for higher Reynolds number flows has proven difficult with the experimental design, yet has revealed the future changes that will be needed to apply this unique experimental idea to the study of the turbulent mix regime. Finally, 3D simulations using the 2D experimental conditions have demonstrated the importance

  9. Numerical and laboratory investigations of transient and steady-state flow in a fractured core

    Kwicklis, E.M.; Thamir, F.; Healy, R.W.; Boughton, C.J. [Geological Survey, Lakewood, CO (United States); Anderton, S. [SAIC, Golden, CO (United States)

    1993-06-01

    An improved understanding of the ability of fractures to transmit water at matric potentials less than zero is essential for evaluating the ability of the rocks of Yucca Mountain, Nevada, to safely isolate nuclear waste. Numerical and experimental investigations of this subnuclear waste. Numerical and experimental investigations of this subject will help substantiate flux estimates of both liquid water and water vapor at Yucca Mountain, aid in assessing the effectiveness of capillary barriers at the contact between nonwelded and fractured welded units, and may provide insight as to the manner in which flow may become concentrated along specific pathways through a network of fractures under conditions of partial saturation. This paper summarizes some of the numerical and laboratory investigations that have been conducted at the US Geological Survey in Denver on a core of welded tuff containing a single fracture parallel to the core axis. The objectives of these investigations were to (1) explore the possibility that the unsaturated hydrologic properties of a fracture could be estimated by applying inverse techniques to the results of transient imbibition experiments, and (2) evaluate the accuracy of estimates of unsaturated fracture hydrologic properties derived from transient tests or numerical modeling through direct steady-state measurements. The core examined in these experiments is 0.0699 m long and has a radius of 0.0208 m. It was obtained from the {open_quotes}columnar zone{close_quotes} of the Tiva Canyon member of the Paintbrush Tuff near Wren Wash on Yucca Mountain. 10 refs., 12 figs.

  10. Laboratory Investigations of the Assessment and Preconcentration of Coastal Sillimanite

    Rao, R. Bhima

    1998-01-01

    India has a high demand for refractory minerals. Sillimanite is one of the minerals having high refractory characteristics. In this paper, the availability of sillimanite along the coastal belt of Orissa coast and its laboratory beneficiation tests are discussed. The results indicate that +0.5 mm contain shell, 2.8 s.g. floats contain quartz, magnetic heavies contain ilmenite and garnet and the non—magnetic heavies contain mainly sillimanite. The raw sand contains 4% sillimanite and the preco...

  11. Experimental investigation of cyclic hygrothermal aging of hybrid composite

    El Yagoubi, Jalal

    2013-04-05

    This work provides an experimental investigation of the cyclic hygrothermal aging of a hybrid composites. We aimed to propose a general framework in the view to further optimize polymer-based composites. It reports experimental data and relevant observations collected during an aging campaign (up to 2000 cycles) where anhydride-cured epoxy samples as well as composites samples are exposed to environmental conditions. The data gathered during the whole campaign reveals that (1) the polymer displays a non-classical sorption behavior (2) the volume change is correlated to the mass uptake (3) the elastic modulus is correlated to the glass transition temperature. Matrix and interface degradation of the hybrid composite is monitored by means of microstructural observations. © 2013 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

  12. Investigating true and false confessions within a novel experimental paradigm.

    Russano, Melissa B; Meissner, Christian A; Narchet, Fadia M; Kassin, Saul M

    2005-06-01

    The primary goal of the current study was to develop a novel experimental paradigm with which to study the influence of psychologically based interrogation techniques on the likelihood of true and false confessions. The paradigm involves guilty and innocent participants being accused of intentionally breaking an experimental rule, or "cheating." In the first demonstration of this paradigm, we explored the influence of two common police interrogation tactics: minimization and an explicit offer of leniency, or a "deal." Results indicated that guilty persons were more likely to confess than innocent persons, and that the use of minimization and the offer of a deal increased the rate of both true and false confessions. Police investigators are encouraged to avoid interrogation techniques that imply or directly promise leniency, as they appear to reduce the diagnostic value of any confession that is elicited. PMID:15943675

  13. Experimental investigation of synthetic aperture flow angle estimation

    Oddershede, Niels; Jensen, Jørgen Arendt

    2005-01-01

    Currently synthetic aperture flow methods can find the correct velocity magnitude, when the flow direction is known. To make a fully automatic system, the direction should also be estimated. Such an approach has been suggested by Jensen (2004) based on a search of the highest cross-correlation as a...... function of velocity and angle. This paper presents an experimental investigation of this velocity angle estimation method based on a set of synthetic aperture flow data measured using our RASMUS experimental ultrasound system. The measurements are performed for flow angles of 60, 75, and 90 deg. with...... respect to the axial direction, and for constant velocities with a peak of 0.1 m/s and 0.2 m/s. The implemented synthetic aperture imaging method uses virtual point sources in front of the transducer, and recursive imaging is used to increase the data rate. A 128 element linear array transducer is used...

  14. Mizunami Underground Research Laboratory project (rock mechanical investigations). MIZ-1 borehole investigations

    In order to establish the scientific and technical basis of geological disposal of high level radioactive waste, Japan Atomic Energy Agency (JAEA) is advancing the geo-scientific research at the Mizunami Underground Laboratory (MIU). In this project, the surface-based investigation phase (Phase I) was finished in fiscal year 2004. Rock mechanics investigations were conducted in Phase I using the MIZ-1 borehole in order to understand the rock mechanical conditions deep underground and to construct a rock mechanical model of the MIU construction site. This report describes the results of these investigations. A brief summary is shown as follows. 1) Determining the average rock physical and mechanical properties using core from Toki Granite are: - apparent specific gravity: 2.62; - unconfined compressive strength (U.C.S.): 173Mpa; - tangent modulus at 50% U.C.S: 51.8Gpa; - poisson's ratio: 0.265. These results are consistent with the results of similar investigations in the nearby Shobasama site. 2) Estimation of in situ stress by stress measurements using cores. Four different methods (AE, DRA, ASR, and DSCA) were applied to estimate the in situ stress state. However the results are very low confidence due to very small deformation during drilling, excepting DSCA. 3) Determining of in situ stress by hydraulic fracturing. The horizontal, maximum principal stress is oriented to NW-SE (using north magnetic pole). Above six hundred meters depth, the in situ stress state is reverse fault type (SH > Sh ≥ Sv overburden pressure ρgh as Sv). But below it, the in situ stress state changed to a wrench or normal fault type (SV ≥ SH > Sh). 4) Rock mechanical model. In consideration of the investigations and geological model, we proposed a rock mechanical model consisting of two in situ stress states and homogeneous, rock mechanical properties. (author)

  15. Environmental epidemiology applied to urban atmospheric pollution: a contribution from the Experimental Air Pollution Laboratory (LPAE

    André Paulo Afonso de

    2000-01-01

    Full Text Available Systematic investigation on the effects of human exposure to environmental pollution using scientific methodology only began in the 20th century as a consequence of several environmental accidents followed by an unexpected mortality increase above expected mortality and as a result of observational epidemiological and toxicological studies conducted on animals in developed countries. This article reports the experience of the Experimental Air Pollution Laboratory at the School of Medicine, University of São Paulo, concerning the respiratory system and pathophysiological mechanisms involved in responses to exposure to pollution using toxicological and experimental procedures, complemented by observational epidemiological studies conducted in the city of São Paulo. It also describes these epidemiological studies, pointing out that air pollution is harmful to public health, not only among susceptible groups but also in the general population, even when the concentration of pollutants is below the limits set by environmental legislation. The study provides valuable information to support the political and economic decision-making processes aimed at preserving the environment and enhancing quality of life.

  16. Experimental investigation of fast ion dynamics in TORPEX toroidal plasmas

    Roulet, Boris

    2010-01-01

    The goal of the present diploma work is to experimentally investigate the fast ion physics in TORPEX plasmas, in which interchange modes with flute characteristics and intermittent transport events, i.e. blobs, are observed to dominate the plasma dynamics. During the first part of the diploma, the Candidate will test different fast ion emitters on a test bench, which will be then mounted into the BN casing to form the fast ion source. In parallel, the Candidate will design an innovative in-ve...

  17. Experimental investigation of resonant MEMS switch with ac actuation

    Pal, Jitendra; Zhu, Yong; Wang, Boyi; Lu, Junwei; Khan, Fahimullah; Viet Dao, Dzung; Wang, Yifan

    2016-06-01

    In this letter, modeling, analysis, and experimental investigation for a resonant MEMS switch are presented. The resonant switch harnesses its mechanical resonance to lower the required actuation voltage by a substantial factor over the switch with static actuation. With alternating actuation voltage at its mechanical resonance frequency of 6.6 kHz, the average capacitance is tuned by changing the gap between fixed and movable electrodes. Based on the proposed actuation method, the device offers 57.44% lower actuation voltage compared with the switch with static actuation.

  18. Experimental investigation of edge localised modes in JET

    Edge Localised Modes (ELMs) in the JET tokamak have been studied experimentally, using density profile and fluctuation data from a multichannel reflectometer and temperature profile data from an ECE heterodyne radiometer. The following topics have been investigated: The radial extent and localisation of the density and temperature profile perturbations caused by the ELMs. Fluctuations in the density and magnetic field in connection with the ELMs. The correlation between the repetition frequency of the L-H transition ELMs, and the plasma edge temperature and density. Trajectories in n-T space prior to ELMs later in the H-mode. (au) (39 refs.)

  19. Experimental and Numerical Investigation of Condensation Shock in Shock Tube

    F.Marsik; P.Sopuch; 等

    1997-01-01

    The homogeneous nucleation with subsequent spontaneous condensation of water,pentanol,and ethanol vapors in a carrier gas are investigated experimentally and theoretically in the expansion part of a shock tube.The precise pressure and MCW measurements give additional information about the wetness,so that the nucleation and condensation rates which are closely coupled for stronger expansion rates are determied more accurately,Predictions of the principle of the minimum of entropy production are compared with experiments performed for water,ethanol and pentanol at different pressures.

  20. Experimental investigation of system effects in stressed-skin elements

    Dela Stang, B.; Isaksson, T.; Hansson, M.

    What kind of behaviour can be expected from stressed-skin elements at failure? To answer this question was a primary objective of the experimental investigation presented in this report. Systems of 3 roof units, each made of 5 parallel beams, have been tested for load-carrying capacity and...... behaviour at failure. Test results are compared with analytical calculations estimating the load-bearing capacity from predicted bending strength of each beam used in the system. The test results show that failure of one beam does not necessarily lead to failure of the whole system. This is an important...

  1. NUMERICAL AND EXPERIMENTAL INVESTIGATION OF FTOW OVER A SEMTCIRCULAR WEIR

    刘春嵘; 呼和敖德; 马文驹

    2002-01-01

    The water flow over a semicircular weir is investigated numericallyand experimentally in this paper. The numerical model solves the Reynolds equationfor a mean flow field with the κ-ε turbulent model. To trace the motion of the freesurface, the VOF method with geometric reconstruction is employed. The velocity ofthe flow is measured by means of LDV technique. Four types of flow patterns, theposition of the separation and reattachment point, the distribution of shear stresson the bed at downstream of the weir are presented and discussed. The numericalresults agree well with the experiment data.

  2. Numerical and experimental investigation into the aerodynamics of dragonfly flight.

    Russell, David; Wang, Z. Jane

    2004-11-01

    Dragonflies have a unique feature in that they drive two pairs of wings independently and modulate the phase delay between them during different modes of flight. To investigate the role of fore-hind wing interactions, we developed a computational tool to simulate flows around multiple wings. We also performed an experiment on tethered dragonflies in order to measure the 3D wing motions and vertical forces. In this talk we report on the comparison of the computed and experimental forces, wing inertia and fluid forces, the passive mechanism of wing rotation, and the effect of fore-hind wing interactions.

  3. Experimental Investigation of a Novel Blast Wave Mitigation Device

    Su, Zhenbi; Peng, Wen; Zhang, Zhaoyan; Gogos, George; Skaggs, Reed; Cheeseman, Bryan; Yen, Chian Fong

    2009-01-01

    A novel blast wave mitigation device was investigated experimentally in this paper. The device consists of a piston-cylinder assembly. A shock wave is induced within the cylinder when a blast wave impacts on the piston. The shock wave propagates inside the device and is reflected repeatedly. The shock wave propagation process inside the device lengthens the duration of the force on the base of the device to several orders of magnitude of the duration of the blast wave, while it decreases the ...

  4. Students' Assessment of Interactive Distance Experimentation in Nuclear Reactor Physics Laboratory Education

    Malkawi, Salaheddin; Al-Araidah, Omar

    2013-01-01

    Laboratory experiments develop students' skills in dealing with laboratory instruments and physical processes with the objective of reinforcing the understanding of the investigated subject. In nuclear engineering, where research reactors play a vital role in the practical education of students, the high cost and long construction time of…

  5. The colloid investigations conducted at the Aespoe Hard Rock Laboratory during 2000-2004

    In 2000, SKB decided to initiate an international colloid project at the Aespoe Hard Rock Laboratory in Sweden. The objectives of the colloid project are to: (i) study the role of bentonite as a colloid source, (ii) verify the background colloid concentration at Aespoe HRL and, (iii) investigate the potential for colloid formation/transport in natural groundwater concentrations. The experimental concepts for the colloid project are: laboratory experiments with bentonite, background field measurements of natural colloids, borehole specific bentonite colloid stability experiments and a fracture specific transport experiment. The activities concerning the laboratory experiments and background field measurements are described in this work; the other activities are ongoing or planned. The following conclusions were made: The bentonite colloid stability is strongly dependent on the groundwater ionic strength. Natural colloids are organic degradation products such as humic and fulvic acids, inorganic colloids (clay, calcite, iron hydroxide) and microbes. Microbes form few but large particles and their concentration increase with increasing organic carbon concentrations. The small organic colloids are present in very low concentrations in deep granitic groundwater. The concentrations can be rather high in shallow waters. The colloid concentration decreases with depth and salinity, since colloids are less stable in saline waters. The colloid content at Aespoe is less than 300 ppb. The colloid content at repository level is less than 50 ppb. The groundwater variability obtained in the boreholes reflects well the natural groundwater variability along the whole HRL tunnel

  6. The colloid investigations conducted at the Aespoe Hard Rock Laboratory during 2000-2004

    Laaksoharju, Marcus [Geopoint AB, Stockholm (Sweden); Wold, Susanna [Royal Inst. of Tech., Stockholm (Sweden). School of Chemical Science and Engineering, Nuclear Chemistry] (eds.)

    2005-12-15

    In 2000, SKB decided to initiate an international colloid project at the Aespoe Hard Rock Laboratory in Sweden. The objectives of the colloid project are to: (i) study the role of bentonite as a colloid source, (ii) verify the background colloid concentration at Aespoe HRL and, (iii) investigate the potential for colloid formation/transport in natural groundwater concentrations. The experimental concepts for the colloid project are: laboratory experiments with bentonite, background field measurements of natural colloids, borehole specific bentonite colloid stability experiments and a fracture specific transport experiment. The activities concerning the laboratory experiments and background field measurements are described in this work; the other activities are ongoing or planned. The following conclusions were made: The bentonite colloid stability is strongly dependent on the groundwater ionic strength. Natural colloids are organic degradation products such as humic and fulvic acids, inorganic colloids (clay, calcite, iron hydroxide) and microbes. Microbes form few but large particles and their concentration increase with increasing organic carbon concentrations. The small organic colloids are present in very low concentrations in deep granitic groundwater. The concentrations can be rather high in shallow waters. The colloid concentration decreases with depth and salinity, since colloids are less stable in saline waters. The colloid content at Aespoe is less than 300 ppb. The colloid content at repository level is less than 50 ppb. The groundwater variability obtained in the boreholes reflects well the natural groundwater variability along the whole HRL tunnel.

  7. Integral Test Facility PKL: Experimental PWR Accident Investigation

    Klaus Umminger

    2012-01-01

    Full Text Available Investigations of the thermal-hydraulic behavior of pressurized water reactors under accident conditions have been carried out in the PKL test facility at AREVA NP in Erlangen, Germany for many years. The PKL facility models the entire primary side and significant parts of the secondary side of a pressurized water reactor (PWR at a height scale of 1 : 1. Volumes, power ratings and mass flows are scaled with a ratio of 1 : 145. The experimental facility consists of 4 primary loops with circulation pumps and steam generators (SGs arranged symmetrically around the reactor pressure vessel (RPV. The investigations carried out encompass a very broad spectrum from accident scenario simulations with large, medium, and small breaks, over the investigation of shutdown procedures after a wide variety of accidents, to the systematic investigation of complex thermal-hydraulic phenomena. This paper presents a survey of test objectives and programs carried out to date. It also describes the test facility in its present state. Some important results obtained over the years with focus on investigations carried out since the beginning of the international cooperation are exemplarily discussed.

  8. Investigations of Solar Prominence Dynamics Using Laboratory Simulations

    Laboratory experiments simulating many of the dynamical features of solar coronal loops have been carried out. These experiments manifest collimation, kinking, jet flows, and S-shapes. Diagnostics include high-speed photography and x-ray detectors. Two loops having opposite or the same magnetic helicity polarities have been merged and it is found that counter-helicity merging provides much greater x-ray emission. A non-MHD particle orbit instability has been discovered whereby ions going in the opposite direction of the current flow direction can be ejected from a magnetic flux tube.

  9. The Monotonicity Puzzle: An Experimental Investigation of Incentive Structures

    Jeannette Brosig

    2010-05-01

    Full Text Available Non-monotone incentive structures, which - according to theory - are able to induce optimal behavior, are often regarded as empirically less relevant for labor relationships. We compare the performance of a theoretically optimal non-monotone contract with a monotone one under controlled laboratory conditions. Implementing some features relevant to real-world employment relationships, our paper demonstrates that, in fact, the frequency of income-maximizing decisions made by agents is higher under the monotone contract. Although this observed behavior does not change the superiority of the non-monotone contract for principals, they do not choose this contract type in a significant way. This is what we call the monotonicity puzzle. Detailed investigations of decisions provide a clue for solving the puzzle and a possible explanation for the popularity of monotone contracts.

  10. Experimental investigation and performance test of heavy duty torque converter

    The present study is an investigation on the characteristics of heavy load toque converter by experimental process. To get the dynamic performance, the dynamometer was used with a parameters of speed, torque, oil pressure and oil flux, etc. The torque converter was tested for various input speed, output oil pressure and input oil flow rate. All experiments were investigated in case that the speed ratio is increased. The torque ratio and capacity factor was in inverse proportion to speed. Engine revolution had a more effects at region of low speed ratio. But, the opposite phenomena were represented increase of efficiency. In result of this experiments, the characteristics of torque converter were not influenced by oil pressure and oil flux

  11. An Experimental Investigation of Hydrogen Production from Biomass

    吕鹏梅; 常杰; 付严; 王铁军; 陈勇; 祝京旭

    2003-01-01

    In gaseous products of biomass steam gasification, there exist a lot of CO, CH4 and other hydrocarbons that can be converted to hydrogen through steam reforming reactions. There exists potential hydrogen production from the raw gas of biomass steam gasification. In the present work, the characteristics of hydrogen production from biomass steam gasification were investigated in a small-scale fluidized bed. In these experiments, the gasifying agent (air) was supplied into the reactor from the bottom of the reactor and the steam was added into the reactor above biomass feeding location. The effects of reaction temperature, steam to biomass ratio, equivalence ratio (ER) and biomass particle size on hydrogen yield and hydrogen yield potential were investigated. The experimental results showed that higher reactor temperature, proper ER, proper steam to biomass ratio and smaller biomass particle size will contribute to more hydrogen and potential hydrogen yield.

  12. Experimental investigation of transitional flow in a toroidal pipe

    Kühnen, J; Hof, B; Kuhlmann, H

    2015-01-01

    The flow instability and further transition to turbulence in a toroidal pipe (torus) with curvature (tube-to-coiling diameter) 0.049 is investigated experimentally. The flow inside the toroidal pipe is driven by a steel sphere fitted to the inner pipe diameter. The sphere is moved with constant azimuthal velocity from outside the torus by a moving magnet. The experiment is designed to investigate curved pipe flow by optical measurement techniques. Using stereoscopic particle image velocimetry, laser Doppler velocimetry and pressure drop measurements, the flow is measured for Reynolds numbers ranging from 1000 to 15000. Time- and space-resolved velocity fields are obtained and analysed. The steady axisymmetric basic flow is strongly influenced by centrifugal effects. On an increase of the Reynolds number we find a sequence of bifurcations. For Re=4075 a supercritical bifurcation to an oscillatory flow is found in which waves travel in the streamwise direction with a phase velocity slightly faster than the mean...

  13. Drag reduction by dimples? - A complementary experimental/numerical investigation

    The paper is concerned with an experimental and numerical investigation of the turbulent flow over dimpled surfaces. Shallow dimples distributed regularly over the wall of a plane channel with large aspect ratio are used to study their effect on the friction drag. The resulting pressure drop in the channel was measured for smooth and dimpled walls. In addition to these investigations on internal flows, an external flow study was performed and boundary-layer profiles were measured using a Pitot-tube rake. Complementary to the measurements, direct numerical simulations for the internal flow configuration with and without dimples were carried out for two different grid resolutions and analyzed in detail. The objective was to clarify whether or not dimples cause reduction of the skin-friction drag

  14. Experimental and Theoretical Status of Borromean Halo Nuclei Structure Investigation

    Petrascu, Marius

    2006-08-01

    An introduction to the work performed in pre-emission of neutrons from 11Li halo nuclei will be presented. The standing present problems in the investigation of the structure of Borromean halo nuclei by means of the Cnn correlation function are outlined. An investigation of the target screening effect on the pre-emission of halo neutrons will be briefly described. It is shown that due to the diminishing of the screening effect the yield of neutron pair pre-emission is expected to be much larger in the case of 12C than in the case of Si target. It is shown that a new experiment on l2C target will allow to solve the standing problems of Cnn and also to test experimentally a recent new theory of Cnn [10 ].

  15. Experimental Investigation of Piston Rings for Internal Combustion Engines

    Klit, Peder; Vølund, Anders

    2008-01-01

    conditions, but this is not the case in real life operation. These problems forms the basis for the experimental investigation. In large two-stroke engines the cylinder oil is supplied to the bearing at discrete locations on the cylinder liner at a specific rate at a certain time. The shifting in lubrication...... assembly. The aim of this paper is to investigate the tribological condition between a piston ring and cylinder. A test apparatus is used to study the interaction between a piston ring and a cylinder liner. In large two stroke engines with cross head bearings the piston height is small compared to smaller...... four stroke engines where the skirt transfers the guide forces to the cylinder liner. The power loss due to piston skirt friction is estimated by comparing two different piston designs. The piston ring experiences hydrodynamic, mixed and boundary lubrication and the squeeze effect of the piston ring is...

  16. EXPERIMENTAL INVESTIGATION OF EMERGENCY GATE SHUTTING FOR ORIFICE TUNNEL

    2002-01-01

    In the process of the emergence gate shutting of one orifice tunnel, a big noise and great vibration may be observed in the mid gate chamber. In order to guarantee the working safety of orifice tunnels, an experimental investiga-tion is carried out in Sichuan University. In the investigation,the fluctuation pressure along the tunnel and the wind velocity in the entry of emergency gate are measured. In the mean time, the fluid state in orifice tunnel is carefully observed and analyzed. The reasons of the noise and vibration in the mid gate chamber are found out and some countermeasures are presented in this paper. The conclusions are useful to the ori-fice tunnels with high water head and huge discharge.

  17. An Experimental and Theoretical Investigation of Electrostatically Coupled Cantilever Microbeams

    Ilyas, Saad

    2016-06-16

    We present an experimental and theoretical investigation of the static and dynamic behavior of electrostatically coupled laterally actuated silicon microbeams. The coupled beam resonators are composed of two almost identical flexible cantilever beams forming the two sides of a capacitor. The experimental and theoretical analysis of the coupled system is carried out and compared against the results of beams actuated with fixed electrodes individually. The pull-in characteristics of the electrostatically coupled beams are studied, including the pull-in time. The dynamics of the coupled dual beams are explored via frequency sweeps around the neighborhood of the natural frequencies of the system for different input voltages. Good agreement is reported among the simulation results and the experimental data. The results show considerable drop in the pull-in values as compared to single microbeam resonators. The dynamics of the coupled beam resonators are demonstrated as a way to increase the bandwidth of the resonator near primary resonance as well as a way to introduce increased frequency shift, which can be promising for resonant sensing applications. Moreover the dynamic pull-in characteristics are also studied and proposed as a way to sense the shift in resonance frequency.

  18. Experimental investigation of effects of external loads on erosive wear

    H. Imrek

    2009-01-01

    Full Text Available Purpose: The purpose of the paper is to investigate effects of external loads on erosive wear.Design/methodology/approach: In this experimental study, specimens were placed on specially designed a specimen holder and then, external tensile loads corresponding to 0%, 20%, 40% and 60% of the specimen’s yield strength were applied on the specimens. For every load step, the specimens were subjected to 15º, 30º, 45º, 60º, 75º and 90º of erodent impact angles. At the end of the tests, effects of external loads and impingement angles on erosive wear were studied. In the experimental set, dry and compressed air was used to impinge erodents onto the test specimens and subsequent wear was investigated. During the tests, the impingement angles were adjusted by turning the specimen holder around its axis. Erodent particles used were SAE G40 having internal uniform martensitic structure and angular geometry. Determination of erodents speed was achieved with the help of the Rotating Double Disc Method. The speed used in the tests was 30 m/s.Findings: At the end of the tests, erosive wear rates were obtained as functions of stresses and impingement angles. Graphs showing variations of erosive wear rates for load values obtained against every impingement angle and yield stress were drawn. Critical impingement angle and load values at which maximum erosion rate was obtained were determined.Research limitations/implications: In researches made on erosive wears so far; there are only few studies dealing with the effects of external loads on the specimens subjected to erosive wear. By considering that stresses may affect the erosive wear, the stress state around contact area as well as material properties, this experimental study has thus, investigated likely effects of stresses on the erosive wear. With the help of the designed special specimen holder, the specimens were subjected to tensile stresses that are lower than the yield strength of the material

  19. Students' Written Arguments in General Chemistry Laboratory Investigations

    Choi, Aeran; Hand, Brian; Greenbowe, Thomas

    2012-11-01

    This study aimed to examine the written arguments developed by college freshman students using the Science Writing Heuristic approach in inquiry-based general chemistry laboratory classrooms and its relationships with students' achievement in chemistry courses. Fourteen freshman students participated in the first year of the study while 19 freshman students participated in the second year of the study. Two frameworks, an analytical and a holistic argument framework, were developed to evaluate the written argument generated by students. The analytical framework scored each argument component separately and allocated a Total Argument score while the holistic framework evaluated the arguments holistically. Three hundred and sixty-eight samples from 33 students were evaluated. Stepwise regression analyses revealed that the evidence and the claims-evidence relationship components were identified as the most important predictors of the Total Argument and the Holistic Argument scores. Students' argument scores were positively correlated with their achievement, as measured by the final grade received for the general chemistry laboratory and the general chemistry lecture course.

  20. Does magical thinking produce neutralising behaviour? An experimental investigation.

    Bocci, Laura; Gordon, P Kenneth

    2007-08-01

    Magical thinking is of relevance to obsessive compulsive disorder (OCD), and has been most widely investigated in relation to the cognitive bias known as thought-action fusion (TAF). This is seen as playing a role in the formation of fears about responsibility for harm. We suggest that magical thinking may also characterise some types of neutralising behaviour, which arise in response to those fears, and are a hallmark of the disorder. In an experimental study of 51 undergraduate students, we assessed whether the use of neutralising behaviours in response to an induction of fears of increasing likelihood for harm is related to a propensity for magical thinking. The 75.5% of participants demonstrated at least one form of neutralising behaviour in response to a TAF-induction task. Neutralising was associated with stronger and more persistent responses to the task, and with questionnaire measures of magical ideation. Those who neutralised did not report higher levels of OCD symptoms. It appears that neutralising is a common response in circumstances that provoke a sense of responsibility for harm. Its occurrence may be linked to magical thinking, however, the results from this experimental investigation suggested that this process may not be specific to OCD. PMID:17403518

  1. Alternate Methods to Experimentally Investigate Shock Initiation Properties of Explosives

    Svingala, Forrest; Lee, Richard; Sutherland, Gerrit; Samuels, Philip

    2015-06-01

    Reactive flow models are desired for many new explosives early in the formulation development stage. Traditionally, these models are parameterized by carefully-controlled 1-D shock experiments, including gas-gun testing with embedded gauges and wedge testing with explosive plane wave lenses (PWL). These experiments are easy to interpret, due to their 1-D nature, but are generally expensive to perform, and cannot be performed at all explosive test facilities. We investigate alternative methods to probe shock-initiation behavior of new explosives using widely-available pentolite gap test donors and simple time-of-arrival type diagnostics. These methods can be performed at a low cost at virtually any explosives testing facility, which allows experimental data to parameterize reactive flow models to be collected much earlier in the development of an explosive formulation. However, the fundamentally 2-D nature of these tests may increase the modeling burden in parameterizing these models, and reduce general applicability. Several variations of the so-called modified gap test were investigated and evaluated for suitability as an alternative to established 1-D gas gun and PWL techniques. At least partial agreement with 1-D test methods was observed for the explosives tested, and future work is planned to scope the applicability and limitations of these experimental techniques.

  2. Experimental investigation of turbulent mixing by Rayleigh-Taylor instability

    A key feature of compressible turbulent mixing is the generation of vorticity via the ∇px ∇(1/ρ) term. This source of vorticity is also present in incompressible flows involving the mixing of fluids of different density, for example Rayleigh-Taylor unstable flows. This paper gives a summary of an experimental investigation of turbulent mixing at a plane boundary between two fluids, of densities ρ1, and ρ2. (ρ1 > ρ2) due to Rayleigh-Taylor instability. The two fluids are near incompressible and mixing occurs when an approximately constant acceleration, g, is applied normal to the interface with direction from fluid 2 to fluid 1. Full details of the experimental programme are given in a set of three reports. Some of the earlier experiments are also described by Read. Previous experimental work and much of the theoretical research has concentrated on studying the growth of the instability from a single wavelength perturbation rather than turbulent mixing. Notable exceptions are published in the Russian literature. A related process, turbulent mixing induced by the passage of shock waves though an interface between fluids of different density is described by Andronov et al. The major purpose of the experiments described here was to study the evolution of the instability from small random perturbations where it is found that large and larger structures appear as time proceeds. A novel technique was used to provide the desired acceleration. The two fluids were enclosed in a rectangular tank, the lighter fluid 2 initially resting on top of the denser fluid 1. One or more rocket motors were then used to drive the tank vertically downwards. The aim of the experimental programme is to provide data for the calibration of a turbulence model used to predict mixing in real situations

  3. Laboratory Investigation of the Electromagnetic Electron-Ion Hybrid Instability

    Enloe, C. Lon; Tejero, Erik; Amatucci, Bill; Crabtree, Chris; Ganguli, Guru

    2015-11-01

    The electromagnetic to electrostatic transition of the electron-ion hybrid instability is currently being studied in the Space Physics Simulation Chamber at NRL. It has been shown by theory that strong gradients in plasma flows perpendicular to the magnetic field can drive electromagnetic waves in the whistler branch. Velocity-sheared flows of this type may naturally arise in the boundary layer between plasmas of different characteristics, such as in the plasma sheet in the Earth's magnetosphere and laser produced plasma expansions across a magnetic field. When the wave vector normalized to the electron skin depth is much larger than 1, the waves are predominantly electrostatic in character and electromagnetic otherwise. These waves are eigenmodes in the direction of the velocity shear and demonstrate a dramatic increase in width after transitioning to an electromagnetic wave. Results from recent experiments will be presented in which this transition is observed. Work supported by the Naval Research Laboratory Base Program.

  4. Further laboratory and theoretical investigations of ammonium dinitramide

    Tulis, A.J.; Snelson, A. [IIT Research Institut, Chicago (United States); Heberlein, C.; Patel, D.L. [U.S. Army Cecom RD et E Center, NVESD (United States)

    1996-12-31

    Hydrogen and deuterated ammonium dinitramide have been vaporized under high vacuum and the IR matrix isolation spectra of the decomposition products obtained. Tentative vibration assignments have been made for HN(NO{sub 2}){sub 2} and DN(NO{sub 2}){sub 2} assuming a symmetrical non-planar structure in which the H or D is bonded to the central nitrogen atom. Other structures are also possible. Ab initio calculations have been made for the various structural isomers of hydrogen dinitramide. Vibration frequencies calculated for the hydrogenated and deuterated species are compared with the experimental values with the object of identifying the molecules` structure. (authors) 3 refs.

  5. Experimental investigation of dispersion phenomenon in a fractured porous medium

    Ali Sanati

    2015-02-01

    Full Text Available Dispersion of fluids flowing through porous media is an important phenomenon in miscible displacement. Dispersion causes instability of miscible displacement flooding; therefore, to obtain and maintain the miscibility zone, the porous medium dispersivity should be considered in displacing fluid volume calculation. Many works have been carried out to investigate the dispersion phenomenon in porous media in terms of theory, laboratory experiments and modeling. What is still necessary is to study the effects of presence of fracture in a porous medium on dispersion coefficient or dispersivity. In this work dispersion phenomenon in a fractured porous medium has been investigated through a series of miscible displacement tests on homogeneous sandstone core samples. Tests were repeated on the same core samples with induced fracture in the flow direction. The effects of fracture on miscible displacement flooding have been studied by comparison of the results of dispersion tests in the absence and presence of fracture. In the presence of fracture, breakthrough time reduced and the tail of effluent S-shaped curve smeared. Moreover, the slope of S-shaped curve at 1 pore volume of injected fluid was lower than homogeneous case which means dispersion coefficient increased. The results presented in this work provide an insight to the understanding of dispersion phenomenon for modeling of miscible displacement process through naturally fractured reservoirs.

  6. Experimental Investigation of Biogas Reforming in Gliding Arc Plasma Reactors

    P. Thanompongchart

    2014-01-01

    Full Text Available Biogas is an important renewable energy source. Its utilization is restricted to vicinity of farm areas, unless pipeline networks or compression facilities are established. Alternatively, biogas may be upgraded into synthetic gas via reforming reaction. In this work, plasma assisted reforming of biogas was investigated. A laboratory gliding arc plasma setup was developed. Effects of CH4/CO2 ratio (1, 2.33, 9, feed flow rate (16.67–83.33 cm3/s, power input (100–600 W, number of reactor, and air addition (0–60% v/v on process performances in terms of yield, selectivity, conversion, and energy consumption were investigated. High power inputs and long reaction time from low flow rates, or use of two cascade reactors were found to promote dry reforming of biogas. High H2 and CO yields can be obtained at low energy consumption. Presence of air enabled partial oxidation reforming that produced higher CH4 conversion, compared to purely dry CO2 reforming process.

  7. Experimental investigation of the acceleration of deflagration in wake flow

    In real gas cloud explosions turbulence is produced by the flow field caused by the combustion process. But also turbulence can be produced by an initial flow field due to atmospheric wind or technical devices. This turbulence may lead to an increased rate of chemical reaction connected with high pressure levels. The reported laboratory-scale experiments are particularly designed in order to investigate the influence of a flow field present at the moment of ignition inside a partially confined hydrocarbon-air gas cloud. Experiments have been done using a flow channel capable to produce an unsteady flow field of combustible gas independent of the combustion process itself. The parameters which have been varied in these tests are the initial flow velocity, the gas-mixture composition and the geometry. The tests have been carried out mainly with stoichiometric ethylene-air and propane-air mixtures. The measured quantities are: pressure time history inside the test section, CH-radical radiation and also high speed photographs have been taken. The results show that the initial flow speed and the reactivity of the gas mixture investigated have a strong influence on the maximum overpressure and the duration of the positive pressure phase but also quenching effect may become important for high flow velocities and mixtures of low reactivity. (author)

  8. Biodiesel from soybean oil: experimental procedure of transesterification for organic chemistry laboratories

    The transesterification procedure of triacylglycerides from soybean oil (in natura and waste oil) to give biodiesel was adapted to semi-micro laboratory scale as an additional experimental technique of nucleophilic acyl substitution for undergraduate courses in Chemistry and related areas. (author)

  9. Diesel Engine Emission Reduction Using Catalytic Nanoparticles: An Experimental Investigation

    Ajin C. Sajeevan

    2013-01-01

    Full Text Available Cerium oxide being a rare earth metal with dual valance state existence has exceptional catalytic activity due to its oxygen buffering capability, especially in the nanosized form. Hence when used as an additive in the diesel fuel it leads to simultaneous reduction and oxidation of nitrogen dioxide and hydrocarbon emissions, respectively, from diesel engine. The present work investigates the effect of cerium oxide nanoparticles on performance and emissions of diesel engine. Cerium oxide nanoparticles were synthesized by chemical method and techniques such as TEM, EDS, and XRD have been used for the characterization. Cerium oxide was mixed in diesel by means of standard ultrasonic shaker to obtain stable suspension, in a two-step process. The influence of nanoparticles on various physicochemical properties of diesel fuel has also been investigated through extensive experimentation by means of ASTM standard testing methods. Load test was done in the diesel engine to investigate the effect of nanoparticles on the efficiency and the emissions from the engine. Comparisons of fuel properties with and without additives are also presented.

  10. Experimental investigation of the Richtmyer-Meshkov instability.

    Weber, Christopher R. (University of Wisconsin-Madison, Madison, WI)

    2011-09-01

    The Richtmyer-Meshkov instability (RMI) is experimentally investigated using several different initial conditions and with a range of diagnostics. First, a broadband initial condition is created using a shear layer between helium+acetone and argon. The post-shocked turbulent mixing is investigated using planar laser induced fluorescence (PLIF). The signature of turbulent mixing is present in the appearance of an inertial range in the mole fraction energy spectrum and the isotropy of the late-time dissipation structures. The distribution of the mole fraction values does not appear to transition to a homogeneous mixture, and it is possible that this effect may be slow to develop for the RMI. Second, the influence of the RMI on the kinetic energy spectrum is investigated using particle image velocimetry (PIV). The influence of the perturbation is visible relatively far from the interface when compared to the energy spectrum of an initially flat interface. Closer to the perturbation, an increase in the energy spectrum with time is observed and is possibly due to a cascade of energy from the large length scales of the perturbation. Finally, the single mode perturbation growth rate is measured after reshock using a new high speed imaging technique. This technique produced highly time-resolved interface position measurements. Simultaneous measurements at the spike and bubble location are used to compute a perturbation growth rate history. The growth rates from several experiments are compared to a new reshock growth rate model.

  11. Experimental Investigation of Ice Phase Change Material Heat Exchangers

    Leimkuehler, Thomas O.; Stephan, Ryan A.

    2012-01-01

    Phase change materials (PCM) may be useful for spacecraft thermal control systems that involve cyclical heat loads or cyclical thermal environments. Thermal energy can be stored in the PCM during peak heat loads or in adverse thermal environments. The stored thermal energy can then be released later during minimum heat loads or in more favorable thermal environments. This can result in a decreased turndown ratio for the radiator and a reduced system mass. The use of water as a PCM rather than the more traditional paraffin wax has the potential for significant mass reduction since the latent heat of formation of water is approximately 70% greater than that of wax. One of the potential drawbacks of using ice as a PCM is its potential to rupture its container as water expands upon freezing. In order to develop a space qualified ice PCM heat exchanger, failure mechanisms must first be understood. Therefore, a methodical experimental investigation has been undertaken to demonstrate and document specific failure mechanisms due to ice expansion in the PCM. A number of ice PCM heat exchangers were fabricated and tested. Additionally, methods for controlling void location in order to reduce the risk of damage due to ice expansion were investigated. This paper presents an overview of the results of this investigation from the past three years.

  12. Experimental investigations on vessel-hole ablation during severe accidents

    This report presents experimental results, and subsequent analyses, of scaled reactor pressure vessel (RPV) failure site ablation tests conducted at the Royal Institute of Technology, Division of Nuclear Power Safety (RIT/NPS). The goal of the test program is to reduce the uncertainty level associated with the phase-change-ablation process, and, thus, improve the characterization of the melt discharge loading on the containment. In a series of moderate temperature experiments, the corium melt is simulated by the binary oxide CaO-B2O3 or the binary eutectic and non-eutectic salts NaNO3-KNO3, while the RPV head steel is represented by a Pb, Sn or metal alloys plate. A complementary set of experiments was conducted at lower temperatures, using water as melt and salted ice as plate material. These experiments scale well to the postulated prototypical conditions. The multidimensional code HAMISA, developed at RIT/NPS, is employed to analyze the experiments with good pre- and post-test predictions. The effects of melt viscosity and crust surface roughness, along with failure site entrance and exit frictional losses on the ablation characteristics are investigated. Theoretical concept was proposed to describe physical mechanisms which govern the vessel-hole ablation process during core melt discharge from RPV. Experimental data obtained from hole ablation tests and separate-effect tests performed at RIT/NPS were used to validate component physical models of the HAMISA code. It is believed that the hole ablation phenomenology is quite well understood. Detailed description of experiments and experimental data, as well as results of analyses are provided in the appendixes

  13. Experimental investigation of bond strength under high loading rates

    Michal, Mathias; Keuser, Manfred; Solomos, George; Peroni, Marco; Larcher, Martin; Esteban, Beatriz

    2015-09-01

    The structural behaviour of reinforced concrete is governed significantly by the transmission of forces between steel and concrete. The bond is of special importance for the overlapping joint and anchoring of the reinforcement, where rigid bond is required. It also plays an important role in the rotational capacity of plastic hinges, where a ductile bond behaviour is preferable. Similar to the mechanical properties of concrete and steel also the characteristics of their interaction changes with the velocity of the applied loading. For smooth steel bars with its main bond mechanisms of adhesion and friction, nearly no influence of loading rate is reported in literature. In contrast, a high rate dependence can be found for the nowadays mainly used deformed bars. For mechanical interlock, where ribs of the reinforcing steel are bracing concrete material surrounding the bar, one reason can be assumed to be in direct connection with the increase of concrete compressive strength. For splitting failure of bond, characterized by the concrete tensile strength, an even higher dynamic increase is observed. For the design of Structures exposed to blast or impact loading the knowledge of a rate dependent bond stress-slip relationship is required to consider safety and economical aspects at the same time. The bond behaviour of reinforced concrete has been investigated with different experimental methods at the University of the Bundeswehr Munich (UniBw) and the Joint Research Centre (JRC) in Ispra. Both static and dynamic tests have been carried out, where innovative experimental apparatuses have been used. The bond stress-slip relationship and maximum pull-out-forces for varying diameter of the bar, concrete compressive strength and loading rates have been obtained. It is expected that these experimental results will contribute to a better understanding of the rate dependent bond behaviour and will serve for calibration of numerical models.

  14. Experimental investigation of bond strength under high loading rates

    Michal Mathias

    2015-01-01

    Full Text Available The structural behaviour of reinforced concrete is governed significantly by the transmission of forces between steel and concrete. The bond is of special importance for the overlapping joint and anchoring of the reinforcement, where rigid bond is required. It also plays an important role in the rotational capacity of plastic hinges, where a ductile bond behaviour is preferable. Similar to the mechanical properties of concrete and steel also the characteristics of their interaction changes with the velocity of the applied loading. For smooth steel bars with its main bond mechanisms of adhesion and friction, nearly no influence of loading rate is reported in literature. In contrast, a high rate dependence can be found for the nowadays mainly used deformed bars. For mechanical interlock, where ribs of the reinforcing steel are bracing concrete material surrounding the bar, one reason can be assumed to be in direct connection with the increase of concrete compressive strength. For splitting failure of bond, characterized by the concrete tensile strength, an even higher dynamic increase is observed. For the design of Structures exposed to blast or impact loading the knowledge of a rate dependent bond stress-slip relationship is required to consider safety and economical aspects at the same time. The bond behaviour of reinforced concrete has been investigated with different experimental methods at the University of the Bundeswehr Munich (UniBw and the Joint Research Centre (JRC in Ispra. Both static and dynamic tests have been carried out, where innovative experimental apparatuses have been used. The bond stress-slip relationship and maximum pull-out-forces for varying diameter of the bar, concrete compressive strength and loading rates have been obtained. It is expected that these experimental results will contribute to a better understanding of the rate dependent bond behaviour and will serve for calibration of numerical models.

  15. Experimental investigations in turbulent buoyant jets of sodium

    Axisymmetric, turbulent buoyant jets are investigated in the sodium test section TEFLU. The character of the flow is divided into three regimes depending on the densimetric Froude number: the pure jet, the buoyant jet in the transition regime and the pure plume. By means of a temperature compensated Miniature Permanentmagnet Flowmeter Probe the mean velocity, mean temperature and intensity of temperature fluctuations are measured simultaneously at axial distances between 3 and 40 initial jet diameters from the orifice. The functional principle of the Miniature Permanentmagnet Flowmeter Probe which allows velocity measurements to be made in the presence of a temperature gradient is described in detail. For all three regimes both the decay laws of the quantities measured along the axis of the containment pipe and the radial profiles are indicated and discussed. With the help of the radial profiles of the mean quantities the axial development of the half-width radii and the axial development of the momentum, buoyancy and volume fluxes are calculated. In addition, the time history of the temperature fluctuations is recorded at several radial positions. The data are analysed according to characteristic values of statistical signal analysis such as minimum value, maximum value, skewness, flatness and according to characteristic functions such as probability density function, autopower spectrum density and autocorrelation function. The experimental results for the axisymmetric, turbulent buoyant jets of sodium are compared with experimental results from the literature and with fluids of molecular Prandtl numbers greater than or equal to 0.7. The basic differences betwen the experimental results obtained for water and for sodium are outlined. Statements are formulated which allow thermo- and fluiddynamic diffusion processes to be transferred from water to sodium. (orig.)

  16. Experimental Investigation of Exhaust Thermoelectric System and Application for Vehicle

    Liu, X.; Deng, Y. D.; Wang, W. S.; Su, C. Q.

    2015-06-01

    In this case study, an energy harvesting system using a thermoelectric power generator (TEG) has been constructed. Experimental investigation of the hot and cold sides of the thermoelectric modules (TMs) in this system has been undertaken to assess the feasibility for automotive applications. Two test benches have been developed to analyze the TM performance and the TEG system characteristics, especially the temperature difference, open-circuit voltage, and maximum power output of the TM and TEG system. As the performance of a TM is most influenced by the applied pressure and the temperature difference, a thermostatic heater, thermostatic water tank, and clamping devices are used in our experimental apparatus, increasing the output power of the TEG system. Based on the test bench, a new system called the "four-TEGs" system was designed and assembled into a prototype vehicle called "Warrior," and the characteristics of the system such as the maximum power output have been studied in road tests. The results show great potential for application of this technology in future vehicles.

  17. Experimental investigation of coarse particle conveying in pipes

    Vlasak Pavel

    2015-01-01

    Full Text Available The advanced knowledge of particle-water mixture flow behaviour is important for safe, reliable, and economical design and operation of the freight pipelines. The effect of the mixture velocity and concentration on the coarse particle – water mixtures flow behaviour was experimentally investigated on an experimental pipe loop of inner diameter D = 100 mm with horizontal, vertical, and inclined pipe sections. Narrow particle size distribution basalt pebbles were used as model of coarse-grained solid particles. The radiometric method was used to measure particle concentration distribution in pipe cross-section. Mixture flow behaviour and particles motion along the pipe invert were studied in a pipe viewing section. The study revealed that the coarse particlewater mixtures in the horizontal and inclined pipe sections were significantly stratified. The particles moved principally in a layer close to the pipe invert. However, for higher and moderate flow velocities the particles moved also in the central part of the pipe cross-section, and particle saltation was found to be dominant mode of particle conveying.

  18. An experimental investigation of the dielectric properties of electrorheological fluids

    A home-made electrorheological (ER) fluid, known as ETSERF, has been created with suspension-based powders dispersed in silicone oil. Because of the special structure of their particles, ETSERF suspensions present a complex behavior. In the absence of an electric field, the ETSERF fluid manifests a near-Newtonian behavior, but when an electric field is applied, it exhibits a pseudoplastic behavior with yield stress. The ER effect under DC electric fields has been experimentally investigated using both hydrous and anhydrous ER fluids. The ER properties are strongly dependent on the dielectric properties of ETSERF suspensions, and hydrous ER fluids have a high dielectric constant and a high relaxation frequency which show a strong electrorheological effect. The relationship between the electrorheological effect and the permittivity of ER fluids has also been extensively studied. Experimental results show that the interfacial polarization plays an important role in the electrorheological phenomenon. The ageing of ETSERF fluids was also studied and it was found that the dielectric properties (mainly the dielectric loss tangent) and ER properties are strongly related to the duration of ageing. A fresh ETSERF suspension exhibits high relaxation frequency and high dielectric constant. These results are mainly explained by the effect of interfacial polarizations

  19. Experimental Investigation and Theoretical Modeling of Nanosilica Activity in Concrete

    Han-Seung Lee

    2014-01-01

    Full Text Available This paper presents experimental investigations and theoretical modeling of the hydration reaction of nanosilica blended concrete with different water-to-binder ratios and different nanosilica replacement ratios. The developments of chemically bound water contents, calcium hydroxide contents, and compressive strength of Portland cement control specimens and nanosilica blended specimens were measured at different ages: 1 day, 3 days, 7 days, 14 days, and 28 days. Due to the pozzolanic reaction of nanosilica, the contents of calcium hydroxide in nanosilica blended pastes are considerably lower than those in the control specimens. Compared with the control specimens, the extent of compressive strength enhancement in the nanosilica blended specimens is much higher at early ages. Additionally, a blended cement hydration model that considers both the hydration reaction of cement and the pozzolanic reaction of nanosilica is proposed. The properties of nanosilica blended concrete during hardening were evaluated using the degree of hydration of cement and the reaction degree of nanosilica. The calculated chemically bound water contents, calcium hydroxide contents, and compressive strength were generally consistent with the experimental results.

  20. Numerical and experimental investigation of the TRIP strain

    In the first part a comprehensive experimental program is presented involving differential thermo-analyses (DTA) as well as dilatation tests under various non-proportional mechanical as well as thermal loading paths with the objective to measure the additional inelastic strain contribution due to transformation induced plasticity (TRIP). A maraging steel exhibiting complete martensitic transformation in a temperature interval ranging from around 150 oC down to about 70 oC is chosen as an appropriate testing material, since its comparatively low martensite start temperature (MS) facilitates measuring and precludes undesirable creep effects. A concept on how to isolate the TRIP strain contribution from the overall strain monitored by the multiaxial testing device is discussed. Particular attention is paid to the evolution of the martensite fraction during transformation and its dependence on the type and the magnitude of the applied mechanical load. The second part deals with the numerical simulation of the thermo-mechanical material behavior using an elastic predictor - radial return algorithm based on the underlying thermodynamic principles as the starting point. A user supplied subroutine has been developed that provides a commercial finite element solver with the proper material response to a given strain increment. The behavior of a three dimensional unit cell consisting of a regular array of cubic elements, each representing a single, arbitrarily oriented grain of a polycrystal is investigated. The good agreement of the numerical results with the experimental data backs the notion of a transformation related backstress is proposed. Refs. 3 (author)

  1. Experimental investigation of resonance curves in dynamic force microscopy

    Polesel-Maris, Jérôme; Piednoir, Agnès; Zambelli, Tomaso; Bouju, Xavier; Gauthier, Sébastien

    2003-09-01

    A precise experimental investigation of the amplitude and phase resonance curves of a driven dynamic force microscope (DFM) cantilever interacting with an Al2O3(0001) surface in ultra-high vacuum is reported. The large amplitude (a few tens of nanometres), high cantilever stiffness (25 N m-1) and high quality factor (a few 104) characterizing these experiments are typical of the frequency modulation (FM) mode of DFM. The whole range of tip-substrate distances where a stationary oscillation of the cantilever can be maintained is explored. It covers two different regimes: a large distance regime where only long range conservative van der Waals interactions contribute and a small distance regime where short range interactions play a significant role. A comparison is made with frequency shift and excitation amplitude curves as a function of the distance acquired in the FM mode. It is also shown that approach-retract amplitude and phase curves usually obtained in the amplitude modulation mode can be extracted from these data. These experimental results are compared with analytical predictions reported in the literature. An excellent agreement is found in the van der Waals domain, allowing us to evaluate the Hamaker constant for the alumina-vacuum-silicon system.

  2. Numerical simulation and experimental investigation of incremental sheet forming process

    HAN Fei; MO Jian-hua

    2008-01-01

    In order to investigate the process of incremental sheet forming (ISF) through both experimental and numerical approaches, a three-dimensional elasto-plastic finite element model (FEM) was developed to simulate the process and the simulated results were compared with those of experiment. The results of numerical simulations, such as the strain history and distribution, the stress state and distribution, sheet thickness distribution, etc, were discussed in details, and the influences of process parameters on these results were also analyzed. The simulated results of the radial strain and the thickness distribution are in good agreement with experimental results. The simulations reveal that the deformation is localized around the tool and constantly remains close to a plane strain state. With decreasing depth step, increasing tool diameter and wall inclination angle, the axial stress reduces, leading to less thinning and more homogeneous plastic strain and thickness distribution. During ISF, the plastic strain increases stepwise under the action of the tool. Each increase in plastic strain is accompanied by hydrostatic pressure, which explains why obtainable deformation using ISF exceeds the forming limits of conventional sheet forming.

  3. Experimental investigation of thermal neutron analysis based landmine detection technology

    Background: Recently, the prompt gamma-rays neutron activation analysis method is wildly used in coal analysis and explosive detection, however there were less application about landmine detection using neutron method especially in the domestic research. Purpose: In order to verify the feasibility of Thermal Neutron Analysis (TNA) method used in landmine detection, and explore the characteristic of this technology. Methods: An experimental system of TNA landmine detection was built based on LaBr3 (Ce) fast scintillator detector and 252Cf isotope neutron source. The system is comprised of the thermal neutron transition system, the shield system, and the detector system. Results: On the basis of the TNA, the wide energy area calibration method especially to the high energy area was investigated, and the least detection time for a typical mine was defined. In this study, the 72-type anti-tank mine, the 500 g TNT sample and several interferential objects are tested in loess, red soil, magnetic soil and sand respectively. Conclusions: The experimental results indicate that TNA is a reliable demining method, and it can be used to confirm the existence of Anti-Tank Mines (ATM) and large Anti-Personnel Mines (APM) in complicated condition. (authors)

  4. Experimental investigations of a chimney-dependent solar crop dryer

    Afriyie, J.K.; Nazha, M.A.A.; Rajakaruna, H. [School of Engineering and Technology, De Montfort University, Queens Building, The Gateway, Leicester LE1 9BH (United Kingdom); Forson, F.K. [Department of Mechanical Engineering, Kwame Nkrumah University of Science and Technology, Kumasi (Ghana)

    2009-01-15

    An experimental investigation into the performance of a solar crop dryer with solar chimney and no air preheating is described. Tests were first performed on the cabinet dryer, using a normal chimney. The trials were repeated with a solar chimney. Still with the solar chimney, further trials were carried out with the roof of the drying chamber inclined further to form a tent dryer. The described tests include no-load tests for airflow rate measurements and drying tests, with cassava as the crop. Air velocities, temperatures, ambient relative humidity and the drop in crop moisture contents at different stages of the drying process are also presented. The effects of the various configurations described above on the drying process are deduced and discussed while comparing the experimental results with one another. In addition, the performance of the dryer in relation to other natural convection dryers is discussed. The results show that the solar chimney can increase the airflow rate of a direct-mode dryer especially when it is well designed with the appropriate angle of drying-chamber roof. However, the increase in flow rate only increases the drying rate when the relative humidity (RH) of the ambient air is below a certain mark (60% for cassava). (author)

  5. Experimental investigation of the Mg-Al-Ca system

    This work focuses on the experimental investigation of the ternary Mg-Al-Ca system using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and metallographic techniques. DSC has permitted real time measurement of the temperature and enthalpy of the phase transformations. One of the invariant transformations predicted by thermodynamic modeling was verified experimentally and found to occur at 513 oC with composition close to 10.8 at.% Ca, 79.5 at.% Mg and 9.7 at.% Al. Three binary compounds are found to have an extended solid solubility into the ternary system: (Mg2Ca) where Al substitute Mg in the binary compound Mg2Ca (Al2Ca) and (Al3Ca8) where Mg substitute Al in the binary compounds Al2Ca and Al3Ca8, respectively. Two morphologies of eutectic structure were observed in the micrographs and supported by solidification curves; a coarse and fine eutectic microstructures due to the existence of Al2Ca and Mg2Ca, respectively

  6. Experimental investigations of the functional morphology of dragonfly wings

    H.Rajabi; A.Darvizeh

    2013-01-01

    Nowadays,the importance of identifying the flight mechanisms of the dragonfly,as an inspiration for designing flapping wing vehicles,is well known.An experimental approach to understanding the complexities of insect wings as organs of flight could provide significant outcomes for design purposes.In this paper,a comprehensive investigation is carried out on the morphological and microstructural features of dragonfly wings.Scanning electron microscopy (SEM) and tensile testing are used to experimentally verify the functional roles of different parts of the wings.A number of SEM images of the elements of the wings,such as the nodus,leading edge,trailing edge,and vein sections,which play dominant roles in strengthening the whole structure,are presented.The results from the tensile tests indicate that the nodus might be the critical region of the wing that is subjected to high tensile stresses.Considering the patterns of the longitudinal corrugations of the wings obtained in this paper,it can be supposed that they increase the load-bearing capacity,giving the wings an ability to tolerate dynamic loading conditions.In addition,it is suggested that the longitudinal veins,along with the leading and trailing edges,are structural mechanisms that further improve fatigue resistance by providing higher fracture toughness,preventing crack propagation,and allowing the wings to sustain a significant amount of damage without loss of strength.

  7. Experimental investigation into scaling models of methane hydrate reservoir

    Highlights: • The scaling criteria for methane hydrate reservoir are built. • The scaling criteria are verified by the experiments in two 3-D simulators. • The scaling criteria are used for predicting gas production of real hydrate reservoir. • Methane of 1.168 × 106 m3 is produced from the hydrate reservoir after 13.9 days. - Abstract: The Cubic Hydrate Simulator (CHS), a three-dimensional 5.8 L cubic pressure vessel, and the Pilot-Scale Hydrate Simulator (PHS), a three-dimensional 117.8 L pressure vessel, are used for investigating the production processes of hydrate. The gas production behaviors of methane hydrate in the porous media using the thermal stimulation method with a five-spot well system are studied. The experimental conditions are designed by a set of scaling criteria for the gas hydrate reservoir. The experimental results verify that the scaling criteria for gas hydrate production are reliable. The scaling criteria are used for predicting the production behavior of the real-scale hydrate reservoir. In the model of the real-scale hydrate reservoir with the size of 36 m × 36 m × 36 m, methane of 1.168 × 106 m3 (STP) is produced from the hydrate reservoir during 13.9 days of gas production. It is obtained that the gas recovery is 0.73, and the final energy efficiency is 9.5

  8. Experimental Investigation on Performance of Pulse Detonation Rocket Engine Model

    LI Qiang; FAN Wei; YAN Chuan-jun; HU Cheng-qi; YE Bin

    2007-01-01

    The PDRE test model used in these experiments utilized kerosene as the fuel, oxygen as oxidizer, and nitrogen as purge gas. The solenoid valves were employed to control intermittent supplies of kerosene, oxygen and purge gas. PDRE test model was 50 mm in inner diameter by 1.2 m long. The DDT (defiagration to detonation transition) enhancement device Shchelkin spiral was used in the test model.The effects of detonation frequency on its time-averaged thrust and specific impulse were experimentally investigated. The obtained results showes that the time-averaged thrust of PDRE test model was approximately proportional to the detonation frequency. For the detonation frequency 20 Hz, the time-averaged thrust was around 107 N, and the specific impulse was around 125 s. The nozzle experiments were conducted using PDRE test model with three traditional nozzles. The experimental results obtained demonstrated that all of those nozzles could augment the thrust and specific impulse. Among those three nozzles, the convergent nozzle had the largest increased augmentation, which was approximately 18%, under the specific condition of the experiment.

  9. Experimental Investigation of Ternary Alloys for Fusion Breeding Blankets

    Choi, B. William [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chiu, Ing L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-26

    Future fusion power plants based on the deuterium-tritium (DT) fuel cycle will be required to breed the T fuel via neutron reactions with lithium, which will be incorporated in a breeding blanket that surrounds the fusion source. Recent work by LLNL proposed the used of liquid Li as the breeder in an inertial fusion energy (IFE) power plant. Subsequently, an LDRD was initiated to develop alternatives ternary alloy liquid metal breeders that have reduced chemical reactivity with water and air compared to pure Li. Part of the work plan was to experimentally investigate the phase diagrams of ternary alloys. Of particular interest was measurement of the melt temperature, which must be low enough to be compatible with the temperature limits of the steel used in the construction of the chamber and heat transfer system.

  10. Cracking in autoclaved aerated concrete: Experimental investigation and XFEM modeling

    Ferretti, D., E-mail: daniele.ferretti@unipr.it [Department of Civil, Environmental, Land Management Engineering and Architecture, University of Parma, P.co Area delle Scienze 181/A, 43124 Parma (Italy); Michelini, E. [Department of Civil, Environmental, Land Management Engineering and Architecture, University of Parma, P.co Area delle Scienze 181/A, 43124 Parma (Italy); Rosati, G. [Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza L. Da Vinci 32, 20133 Milano (Italy)

    2015-01-15

    The paper aims to investigate and model cracking development in beams and deep-beams made of autoclaved aerated concrete (AAC). Fracture mechanics of AAC has been first studied by performing three-point bending tests on beams, similar to those commonly used for ordinary concrete elements. In some of these tests, crack growth has been also monitored by using ESPI laser technique. In this way, it has been possible to calibrate the main parameters of a proper cohesive law by means of extended finite element inverse analysis. Subsequently, cracking tests have been also performed on deep-beams, whose behavior is more representative of full scale walls. To validate the proposed cohesive law, deep-beam experimental behavior has been finally simulated through XFEM.

  11. Experimental Investigation of Piston Rings for Internal Combustion Engines

    Christiansen, Jens; Klit, Peder; Vølund, Anders; Hwang, Jong-Hyun

    One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. A very important condition for describing the frictional behavior of a piston ring correctly is knowledge about the amount of lubricant present. For piston rings the external...... conditions, but this is not the case in real life operation. These problems forms the basis for the experimental investigation. In large two-stroke engines the cylinder oil is supplied to the bearing at discrete locations on the cylinder liner at a specific rate at a certain time. The shifting in lubrication...... regimes and the non-uniform oil distribution opens for the possibility of starved conditions for the piston ring bearing. Therefore it is important to measure the oil distribution on the liner as a function of the operating conditions. The amount of lubricant available is reflected in the friction...

  12. Experimental investigation of air bubble flows in a water pool

    This paper presents experimental results on rising bubbles in the wetwell of a boiling water reactor (BWR) in a loss-of-coolant accident in the pressure suppression pool (PSP). This accident scenario includes three processes: blowdown and associated water slug phenomena, bubble dynamics and related water flow during continuous release of gases and development of a thermal stratification. The paper covers the middle phase where air is fed through a downcomer. The developments of bubble formation and bubble flow are investigated by means of high speed videos. Diameter, velocity, formation frequency and breakup distance of bubbles are evaluated using automated image evaluation procedures. The experiments have been performed in the cylindrical vessel of the THAI test facility with a height of 9.2 m and a diameter of 3.2 m. (author)

  13. Experimental Investigation of Ternary Alloys for Fusion Breeding Blankets

    Future fusion power plants based on the deuterium-tritium (DT) fuel cycle will be required to breed the T fuel via neutron reactions with lithium, which will be incorporated in a breeding blanket that surrounds the fusion source. Recent work by LLNL proposed the used of liquid Li as the breeder in an inertial fusion energy (IFE) power plant. Subsequently, an LDRD was initiated to develop alternatives ternary alloy liquid metal breeders that have reduced chemical reactivity with water and air compared to pure Li. Part of the work plan was to experimentally investigate the phase diagrams of ternary alloys. Of particular interest was measurement of the melt temperature, which must be low enough to be compatible with the temperature limits of the steel used in the construction of the chamber and heat transfer system.

  14. Experimental investigation of turbulent flows in pipe junctions

    Branching, three-dimensional, incompressible internal flows are examined in detail in circular pipe configurations at an experimental plant for water and at a test bench for air. Laminar and turbulent flows are made visible in water for Re4. Typical phenomena are described in detail, e.g. separations, secondary flows and locally non-stationary behavior under stationary inflow conditions and outflow conditions. Wall pressure distributions for turbulent flows up to Re=105 measured at the same test bench supply a good explanation for a number of observed effects. A quantitative investigation of turbulent velocity fields of selected flow cases up to outflow lengths of 10D is carried out in air with the aid of hot-wire anemometry. (orig./DG)

  15. NUMERICAL AND EXPERIMENTAL INVESTIGATION OF BEVELED TRAILING EDGE FLOW FIELDS

    MOSALLEM M. M.

    2008-01-01

    The characteristics of flow past beveled trailing edges attached to flat plates have been investigated numerically and experimentally. The test models used in the present study were two 2D blunt-faced flat plates having asymmetric beveled trailing edges of angles 27° and 60°. The numerical simulation results display an asymmetric wake behind the 27° beveled trailing edge and von karmen street vortices behind the 60° beveled trailing edge. The flow visualization using cavitation technique showed the same observations of the numerical simulation. Therefore, it is obvious that the trailing edge geometry has a pronounced effect on the wake development and vortex shedding. Also, it is concluded that the cavitation phenomenon can be used as a visualization technique at high flow velocities.

  16. An experimental-differential investigation of cognitive complexity

    2009-12-01

    Full Text Available Cognitive complexity as defined by differential and experimental traditions was explored to investigate the theoretical advantage and utility of relational complexity (RC theory as a common framework for studying fluid cognitive functions. RC theory provides a domain general account of processing demand as a function of task complexity. In total, 142 participants completed two tasks in which RC was manipulated, and two tasks entailing manipulations of complexity derived from the differential psychology literature. A series of analyses indicated that, as expected, task manipulations influenced item difficulty. However, comparable changes in a psychometric index of complexity were not consistently observed. Active maintenance of information across multiple steps of the problem solving process, which entails strategic coordination of storage and processing that cannot be modelled under the RC framework was found to be an important component of cognitive complexity.

  17. An experimental investigation of glare and restructured fiber metal laminates

    Benedict, Adelina Vanessa

    Fiber Metal Laminates (FMLs) are a group of materials fabricated by bonding glass/epoxy layers within metal layers. This class of materials can provide good mechanical properties, as well as weight savings. An FML known as Glass Laminate Aluminum Reinforced Epoxy (GLARE) was studied. An experimental investigation comprising of microscopy and tensile testing was carried out using different grades of GLARE. Microscopy revealed the construction details of GLARE, while tensile testing provided means of measuring and analyzing its stress-strain responses. Next, different metal surface pretreatment methods were explored. These included sandblasting, Phosphoric Acid Anodizing (PAA), and AC-130 Sol-Gel treatment. Woven S-2 glass, an epoxy adhesive, and aluminum alloy sheet metal were used to fabricate restructured FMLs using time and cost effective procedures. Additional microscopy and tensile testing allowed for comparisons with GLARE and aircraft grade aluminum alloys. The restructured FMLs showed similar behaviors to GLARE with potential significant improvements in fabrication efficiency.

  18. Experimental Investigation of Turbulence Specifications of Turbidity Currents

    B Firoozabadi

    2010-01-01

    Full Text Available The present study investigates the turbulence characteristic of turbidity current experimentally. The three-dimensional Acoustic-Doppler Velocimeter (ADV was used to measure the instantaneous velocity and characteristics of the turbulent flow. The experiments were conducted in a three-dimensional channel for different discharge flows, concentrations, and bed slopes. Results are expressed at various distances from the inlet, for all flow rates, slopes and concentrations as the distribution of turbulence energy, Reynolds stress and the turbulent intensity. It was concluded that the maximum turbulence intensity happens in both the interface and near the wall. Also, it was observed that the turbulence intensity reaches its minimum where maximum velocity occurs.

  19. Cracking in autoclaved aerated concrete: Experimental investigation and XFEM modeling

    The paper aims to investigate and model cracking development in beams and deep-beams made of autoclaved aerated concrete (AAC). Fracture mechanics of AAC has been first studied by performing three-point bending tests on beams, similar to those commonly used for ordinary concrete elements. In some of these tests, crack growth has been also monitored by using ESPI laser technique. In this way, it has been possible to calibrate the main parameters of a proper cohesive law by means of extended finite element inverse analysis. Subsequently, cracking tests have been also performed on deep-beams, whose behavior is more representative of full scale walls. To validate the proposed cohesive law, deep-beam experimental behavior has been finally simulated through XFEM

  20. Experimental Investigation of Software Testing and Reliability Assessment Methods (EISTRAM)

    The Experimental Investigation of Software Testing and Reliability Assessment Methods (EISTRAM) project builds on experiences from the RESTRAM review project, which pinpointed certain reliability assessment methods as particularly interesting. The focus for the EISTRAM project is the PIE-technique, proposed by Jeffrey Voas, a technique to estimate the sensitivity of programs. PIE is a reverse acronym for Execution, Infection and Propagation, the three stages needed for a code error to produce a program failure. This progress report contains a description of the PIE-technique and the statistical fundament of the technique. It presents a classification of the syntactic mutants, and criteria for the selection of mutants to use in the PIE analysis. Issues concerning implementation of the technique are described, as well as results from using the technique on three test programs. (author)

  1. EXPERIMENTAL AND NUMERICAL INVESTIGATIONS ON HORIZONTAL OIL-GAS FLOW

    2007-01-01

    Experiments were carried out to investigate the characteristics of oil-gas flow in a horizontal pipe on a large scale (with the inner diameter D = 125 mm). With the experimental data, the flow patterns were presented. Through the analyses for the flow regime transition, it was found that there was a critical superficial velocity of liquid phase for the flow regime transiting from stratified flow to slug flow. The slug flow could not occur until the superficial velocity of liquid phase was higher than the critical velocity. For the flow pattern transiting from stratified to slug flow, the transmitting velocity of gas phase decreases with the augmentation of superficial velocity of liquid phase. On the basis of the experiments, numerical simulations of different flow patterns and their transitions were performed with the use of the Volume Of Fluid (VOF) technique. The results of the computations are shown to match well with the measured data in the experiments.

  2. A Novel Experimental Setup to Investigate Magnetized Dusty Plasmas

    Romero-Talamas, C. A.; Larocque, P.; Alvarez, J.; Sardin, J.

    2013-10-01

    Progress on the design and construction of a novel experimental setup to investigate dusty plasmas at the University of Maryland, Baltimore County (UMBC) is presented. The setup includes separation adjustability of discharge electrodes and their orientation with respect to gravity without breaking vacuum, and a pair of water-cooled coils to produce magnetic fields with strengths of up to several Tesla. The coils' orientation is also designed to be adjustable with respect to gravity. A pulse-forming network to power the coils with flattop times of several seconds is under design. The setup is mounted inside a large glass bell jar to provide wide optical access to the dusty plasmas, and to minimize interference of chamber walls and mounts with imposed electric or magnetic fields. Planned experiments include crystallization and wave propagation under strong magnetic fields.

  3. Border Collision Route to Quasiperiodicity: Numerical Investigation and Experimental Confirmation

    Zhusubaliyev, Zhanybai; Mosekilde, Erik; Maity, S.; Mohanan, S.; Banerjee, S.

    2006-01-01

    Numerical studies of higher-dimensional piecewise-smooth systems have recently shown how a torus can arise from a periodic cycle through a special type of border-collision bifurcation. The present article investigates this new route to quasiperiodicity in the two-dimensional piecewise-linear normal...... periodicity, e.g., a period-5 focus. This article also contains a discussion of torus destruction via a homoclinic bifurcation in the piecewise-linear normal map. Using a dc–dc converter with two-level control as an example, we report the first experimental verification of the direct transition to...... quasiperiodicity through a border-collision bifurcation. ©2006 American Institute of Physics...

  4. Experimental Investigation into Magnetortheological Damper Subjected to Impact Loads

    XIANG Hengbo; FANG Qin; GONG Ziming; WU Hao

    2008-01-01

    A good mechanical model of magnetorheological damper (MRD) is essential to predict the shock isolation performance of MRD in numerical simulation.But at present,the mechanical models of MRD were all derived from the experiment subjected to harmonic vibration loads.In this paper,a commercial MRD (type RD-1005-3) manufactured by Lord Corporation was studied experimentally in order to investigate its isolation performance under the impact loads.A new mechanical model of MRD was proposed according to the data obtained by impact test.A good agreement between the numerical results and test data was observed,which showed that the model was good to simulate the dynamic properties of MRD under impact loads.It is also demonstrated that MRD can improve the acceleration and displacement response of the structure obviously under impact loads.

  5. Experimental and theoretical investigation of anaerobic fluidized bed biofilm reactors

    M. Fuentes

    2009-09-01

    Full Text Available This work presents an experimental and theoretical investigation of anaerobic fluidized bed reactors (AFBRs. The bioreactors are modeled as dynamic three-phase systems. Biochemical transformations are assumed to occur only in the fluidized bed zone. The biofilm process model is coupled to the system hydrodynamic model through the biofilm detachment rate; which is assumed to be a first-order function of the energy dissipation parameter and a second order function of biofilm thickness. Non-active biomass is considered to be particulate material subject to hydrolysis. The model includes the anaerobic conversion for complex substrate degradation and kinetic parameters selected from the literature. The experimental set-up consisted of two mesophilic (36±1ºC lab-scale AFBRs (R1 and R2 loaded with sand as inert support for biofilm development. The reactor start-up policy was based on gradual increments in the organic loading rate (OLR, over a four month period. Step-type disturbances were applied on the inlet (glucose and acetic acid substrate concentration (chemical oxygen demand (COD from 0.85 to 2.66 g L-1 and on the feed flow rate (from 3.2 up to 6.0 L d-1 considering the maximum efficiency as the reactor loading rate switching. The predicted and measured responses of the total and soluble COD, volatile fatty acid (VFA concentrations, biogas production rate and pH were investigated. Regarding hydrodynamic and fluidization aspects, variations of the bed expansion due to disturbances in the inlet flow rate and the biofilm growth were measured. As rate coefficients for the biofilm detachment model, empirical values of 3.73⋅10(4 and 0.75⋅10(4 s² kg-1 m-1 for R1 and R2, respectively, were estimated.

  6. Laboratory Investigation of Noise-Canceling Headphones Utilizing ``Mr. Blockhead''

    Koser, John

    2013-09-01

    While I was co-teaching an introductory course in musical acoustics a few years ago, our class investigated several pieces of equipment designed for audio purposes. One piece of such equipment was a pair of noise-canceling headphones. Our students were curious as to how these devices were in eliminating background noise and whether they indeed block low-frequency sounds as advertised.

  7. Clinical and laboratory investigation of experimentaly infected broilers with CIAV

    Kapetanov Miloš C.

    2004-01-01

    Full Text Available Chicken infectious anemia (CIA is widespread viral disease in countries with the intensive poultry industry. In susceptible birds CIAV causes anemia subcutaneous and intramuscular hemorrhages, lymphoid tissue atrophy immunosuppression, cachexia and increased mortality. Protection of progeny relies not only on age resistance but also on maternally delivered antibodies (Mabs so possessing the information on level and persistence of Mabs is of great significance. In our study experimental infection with CIAV was performed on one and seven days old broiler chickens from naturally infected parent flock during the rearing period. In infected birds, clinical signs hematological findings and humoral immune response were examined. After euthanasia, we looked for specific pathomorphological and histopathological changes that indicate the presence of CIAV infection. In all one and seven days old chickens maternally derived antibodies were established. No clinical signs of CIA were observed, hematological findings showed no deviation from referent values, and there were no specific pathomorphological and histopathological changes at postmortem examination. According to previous knowledge, only serological negative flock if infected in time of laying represent risk for vertical transmission to progeny where typical disease with mortality will appear. The absence of Mabs in one day old chickens is critical point in break of disease. Typical clinical picture in day old chickens rises only when vertical transmission occurs.

  8. Laboratory Investigation of Entrainment and Mixing in Oceanic Overflows

    Philippe, Odier; Ecke, Robert E

    2013-01-01

    We present experimental measurements of a wall-bounded gravity current, motivated by characterizing natural gravity currents such as oceanic overflows. We use particle image velocimetry and planar laser-induced fluorescence to simultaneously measure the velocity and density fields as they evolve downstream of the initial injection from a turbulent channel flow onto a plane inclined at 10$^\\circ$ with respect to horizontal. The turbulence level of the input flow is controlled by injecting velocity fluctuations upstream of the output nozzle. The initial Reynolds number based on Taylor microscale of the flow, R$_\\lambda$, is varied between 40 and 120, and the effects of the initial turbulence level are assessed. The bulk Richardson number $Ri$ for the flow is about 0.3 whereas the gradient Richardson number $Ri_g$ varies between 0.04 and 0.25, indicating that shear dominates the stabilizing effect of stratification. Kelvin-Helmholtz instability results in vigorous vertical transport of mass and momentum. We pres...

  9. Zirconia abutments and restorations: from laboratory to clinical investigations.

    Ferrari, M; Vichi, A; Zarone, F

    2015-03-01

    In last years the use of zirconia in dentistry has become very popular. Unfortunately, the clinical indications for a dental use of zirconia are not completely clear yet, neither are their limitations. The objective of this review was to evaluate the basic science knowledge on zirconia and to discuss some aspects of the clinical behavior of zirconia-based restorations. In particular, one of the goals was highlighting the possible correlation between in vitro and in vivo studies. The definition of concepts like success, survival and failure was still debated and the correlation between in vitro results and predictability of clinical behavior was investigated. PMID:25576437

  10. Experimental investigation of water sprayed finned heat exchanger tube bundles

    Experimental investigations have been made to study the performance of two finned tube-bundle heat exchangers (FORGO type) when wetted by water sprays. The heat exchangers are designed to cool water in a dry cooling tower. The test-elements had a frontal area of 1 m2. The water sprays were created by 20 nozzles, 200 mm in front of the heat exchangers. Air velocities at the inlet of the coolers were in the range 0,8 m/s to 12 m/s and initial temperature differences ITD reached 45 degrees C. The test facility was designed to determine the combined latent and sensible heat fluxes in the wetted heat exchanger, the airside pressure drop and the air humidity and temperature at the exchanger inlet and outlet, and to measure the weight of the water wetting the cooler's surface. The sprayed test elements were investigated in different positions, but most of the experiments were carried out in the position with the fins horizontal