WorldWideScience

Sample records for laboratory experimental investigation

  1. Laboratory investigations

    International Nuclear Information System (INIS)

    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. Experimental and numerical investigations in the near-burner region of a laboratory scale burner

    Energy Technology Data Exchange (ETDEWEB)

    N.G. Orfanoudakis; A. Hatziapostolou; K. Krallis; K. Sardi; A. Fatsis; N. Vlachakis; St. A. Mavromatis; V.D. Tsoukalas [TEI Chalkis (Greece). Mechanical Engineering Department, Laboratory for Steam Boilers, Turbines & Thermal Plants

    2005-07-01

    An experimental and numerical investigation on the effect of swirl on the motion of coal particles in the near-burner region of a multi-fuel swirl-stabilised laboratory burner of total thermal input of 100kW, has been performed. The burner was designed as a scale model of a 10MW coal burner operating in a cement rotary kiln, produced flames of different aerodynamic characteristics and was able to burn a combination of gaseous, liquid and pulverised solid fuels. Temperature and Laser Doppler measurements confirmed the ability of the burner to produce close-to-industrialconditions. Velocity measurements showed that the flow field was axisymmetric and an internal recirculation zone (IRZ) in the shape of a toroidal vortex was formed around the centreline for swirl numbers of at least 0.65. A 60% increase in the swirl number, from 0.65 to 0.9, resulted in a 30% widening of the IRZ. Solid particle measurements revealed that the width of the zone where coal particles recirculate is 20% larger than that formed in the single phase case and that most of the coal particles are centrifuged away from the IRZ.. The flow field was modeled as 2D axisymmetric and results were obtained with both the RNG and k-{epsilon} turbulence models and results were shown to be in good agreement with the measurements even at the high swirl number, when the RMG model was used. Lagrangian tracking of coal particles in the range of 1 to 150 {mu}m was also performed by as a function of swirl number. The calculations revealed that particles of diameter larger than about 20 {mu}m are centrifuged away from the IRZ in accordance to the measurements while particles larger than 100 {mu}m, due to their high inertia remain on the IRZ boundary and are neither centrifuged nor entrained inside the recirculation zone, The calculations showed that the effect of centrifuging is decreased when the swirl number of reduced. 13 figs., 1 tabs.

  3. Experimental Investigation of Beam Breakup in the Jefferson Laboratory 10 kW FEL Upgrade Driver

    CERN Document Server

    Tennant, Chris; Douglas, David; Hoffstaetter, Georg Heinz; Jordan, Kevin; Merminga, Lia; Pozdeyev, Eduard; Simrock, Stefan; Smith, Todd I; Wang, Haipeng

    2005-01-01

    In recirculating accelerators, and in particular energy recovery linacs (ERLs), the maximum current has been limited by multipass, multibunch beam breakup (BBU), which occurs when the electron beam interacts with the higher-order modes (HOMs) of an accelerating cavity on the accelerating pass and again on the energy recovered pass. This effect is of particular concern in the design of modern high average current energy recovery accelerators utilizing superconducting technology. Experimental observations of the instability at the Jefferson Laboratory 10 kW Free-Electron Laser (FEL) are presented. Measurements of the threshold current for the instability are presented and compared to the predictions of several BBU simulation codes. To further characterize the instability, beam based measurements were made to determine the orientation of the dangerous HOMs. With BBU posing a threat to high current beam operation in the FEL, several suppression schemes were developed. These include direct damping of the dangerous...

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

    CERN Document Server

    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. Superconducting inductive pulsed power supply for electromagnetic launchers: Design aspects and experimental investigation of laboratory set-up

    Energy Technology Data Exchange (ETDEWEB)

    Weck, W.; Ehrhart, P.; Mueller, A.; Reiner, G. [Magnet-Motor GmbH, Starnberg (Germany)

    1997-01-01

    The principle of the superconducting inductive energy storage and of superconducting pulse switching is reviewed. Design criteria are discussed by introducing two different laboratory set-ups. Special emphasis will be laid on the methods of charging the energy storage and on the pulse switching. The layout and dimensioning of an experimental pulsed power supply with an energy capacity of 4 MJ are described. First experimental results are presented and future development steps are discussed.

  6. Laboratory Experimentation in Economics

    OpenAIRE

    Dimitrios Koumparoulis

    2013-01-01

    Experimental economics is the application of experimental methods to study economic questions. Data collected in experiments are used to estimate effect size, test the validity of economic theories, and illuminate market mechanisms. Economic experiments usually use cash to motivate subjects, in order to mimic real-world incentives. Experiments are used to help understand how and why markets and other exchange systems function as they do. A fundamental aspect of the subject is design of experi...

  7. A Remote Laboratory Experimentation Network.

    OpenAIRE

    C. Schmid(n); Eikaas, T. I.; Foss, B.; Gillet, D

    2001-01-01

    This contribution presents a remote laboratory project with a new business model that aims at bringing physical experimentation back into the learning arena, where remotely operable laboratory experiments used in advanced education and training schemes are made available to a global market. This is done via the Internet using a set of e-commerce and advanced information and communication technology solutions. The project will add online remote experimentation to distance learning techniques. ...

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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…

  10. Laboratory Investigations on Percussive Drilling

    Science.gov (United States)

    Kivade, S. B.; Murthy, Ch. S. N.; Vardhan, Harsha

    2013-10-01

    The laboratory investigation was carried out on ten rock samples using pneumatic drill with drill bits of different diameters. In general, the process of drilling always produces sound. Sound is generated from the bit-rock interface regardless of the material of the bit used in drilling. The predicted sound level and penetration rate are a product of the drill power and the physical properties of the rocks penetrated. Rock samples were collected from the field and physical properties of the rocks were determined in the laboratory. The sound level and penetration rates were correlated with the rock properties. The compressive strength and abrasivity exhibit strong correlations with the sound level and penetration rate. It was concluded that, among the rock properties included in this study, the compressive strength and abrasivity values are the dominant ones affecting the penetration rate and sound level of percussive drills. Though ten rock samples have been covered in this study, detailed analysis of only one of them is presented.

  11. Experimental facility of innovative types as the laboratory analog of research reactor experimental device

    International Nuclear Information System (INIS)

    The paper analyses capability of creating laboratory analogs of complex experimental facilities at research reactors utilizing power radionuclide neutron sources fabricated in industrial conditions. Some experimental and calculational investigations of neutron-physical characteristics are presented, which have been attained at the RIZ research reactor laboratory analog. Experimental results are supplemented by calculational investigations, fulfilled by means of the BRAND three-dimensional computational complex and the ROZ-6 one-dimensional program. 4 refs.; 3 figs

  12. Experimental investigations of long-term interactions of molten UO2 with MgO and concrete at Argonne National Laboratory

    International Nuclear Information System (INIS)

    Experimental work at Argonne is being performed to investigate the long-term molten core debris retention capability of the ex-vessel cavity following a postulated meltdown accident. The eventual objective of the work is to determine if normal structural material (concrete) or a specifically selected sacrificial material (MgO) located in the ex-vessel cavity region can effectively contain molten core debris. The materials under investigation at ANL are various types of concrete (limestone, basalt and magnetite) and commercially-available MgO brick. Results are presented of the status of real material experimental investigation at ANL into 1) molten UO2 pool heat transfer, 2) long-term molten UO2 penetration into concrete and 3) long-term molten UO2 penetration into refractory substrates. The decay heating in the fuel has been simulated by direct electrical heating permitting the study of the long-term interaction

  13. Experimental investigations of long-term interactions of molten UO2 with MgO and concrete at Argonne National Laboratory

    International Nuclear Information System (INIS)

    Experimental work at Argonne is being performed to investigate the long-term molten-core-debris retention capability of the ex-vessel cavity following a postulated meltdown accident. The eventual objective of the work is to determine if normal structural material (concrete) or a specifically selected sacrificial material (MgO) located in the ex-vessel cavity region can effectively contain molten core debris. The materials under investigation at ANL are various types of concrete (limestone, basalt and magnetite) and commercially-available MgO brick. Results are presented of the status of real material experimental investigation at ANL into (1) molten UO2 pool heat transfer, (2) long-term molten UO2 penetration into concrete and (3) long-term molten UO2 penetration into refractory substrates. The decay heating in the fuel has been simulated by direct electrical heating permitting the study of the long-term interaction

  14. Experimental investigation of wave boundary layer

    DEFF Research Database (Denmark)

    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...... oscillating seabed. A brief account is given of measured quantities, measurement techniques (LDA, PIV, flow visualization) and limitations/constraints in the experimental investigation of the wave boundary layer in the laboratory. The second section concentrates on uniform oscillating boundary layers with a....... Results of recent research on wave boundary layers over a bed with large roughness (such as a/ks = O(1)) are also included in the review. The fourth section describes the effect of superimposed current on the wave boundary layer. The entire ¿spectrum¿, namely from the wave-dominated regime to the current...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  16. Laboratory Investigations into the Extreme Universe

    CERN Document Server

    Chen, P

    2003-01-01

    Recent years have seen tremendous progress in our understanding of the extreme universe, which in turn points to even deeper questions to be further addressed. History has shown that the symbiosis between direct observations and laboratory investigations is instrumental in the progress of astrophysics. Current frontier astrophysical phenomena related to particle astrophysics and cosmology typically involve one or more of the following conditions: (1) extremely high energy events;(2) very high density, high temperature processes; (3) super strong field environments. Laboratory experiments using high intensity lasers and particle beams can calibrate astrophysical observation or detection processes, investigate the underlying dynamics of astrophysical phenomena, and probe fundamental physics in extreme limits. We give examples of possible laboratory experiments that investigate into the extreme universe.

  17. Experimental investigations of ICRF effects

    International Nuclear Information System (INIS)

    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

  18. Contest Design: An Experimental Investigation

    OpenAIRE

    Sheremeta, Roman

    2009-01-01

    This paper experimentally compares the performance of four simultaneous lottery contests: a grand contest, two multiple prize settings (equal and unequal prizes), and a contest which consists of two subcontests. Consistent with the theory, the grand contest generates the highest effort levels among all simultaneous contests. In multi-prize settings, equal prizes produce lower efforts than unequal prizes. The results also support the argument that joint contests generate higher efforts than an...

  19. Experimental Investigations on Market Behavior

    OpenAIRE

    Žakelj, Blaž

    2012-01-01

    This thesis is a collection of three essays on inflation expectations, forecasting uncertainty, and the role of uncertainty in sequential auctions, all using experimental approach. Chapter 1 studies how individuals forecast inflation in fictitious macroeconomic setup and analyzes the effect of monetary policy rules on their decisions. Results display heterogeneity in inflation forecasting rules and demonstrate the importance of adaptive learning forecasting if model switching is assumed. Chap...

  20. Laboratory Experimental Design of Molecular Cloud Implosions

    Science.gov (United States)

    Keiter, Paul; Stone, James; Trantham, Matt; Malamud, Guy; Klein, Sallee

    2012-10-01

    The interaction of ionizing radiation with its surrounding medium is a ubiquitous issue in astrophysics. Although the interaction can occur in many environments, the interaction of an ionization front with a molecular cloud is of particular interest. Material ablated form the cloud can form turbulent structure [Peters et al, 2008] and coupled with the radiatively-driven implosion of the cloud can have important consequences in stellar formation. Our understanding of stellar formation is based on computer simulations and models. To improve our understanding of these models, data is required. We present the design of an experiment to study the interaction of an ionization front with a high density sphere, which acts as a surrogate for the molecular cloud. Irradiating a high-Z foil with laser beams generates the ionization front. The ionization front will propagate in a low density medium before interacting with the sphere. We will present our experimental design along with initial simulations. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-FG52-09NA29548.

  1. Laboratory investigation of tyre sliding grip coefficient

    OpenAIRE

    Ivanov, Rosen; Rusev, Rusi; Ilchev, Plamen

    2006-01-01

    The paper presents the results of a laboratory investigation on the variation of the tyre sliding grip coefficient depending on the tyre construction, the air pressure, the vertical load and the wheel camber. Eight different models of tyres are tested. A significant reduction of the tyre sliding grip coefficient on a hard ground was registered, when the tyre pressure is low and the wheel camber is bigger. The analysis of results and explanation of causes are done.

  2. Laboratory investigation of constitutive property scaling behavior

    International Nuclear Information System (INIS)

    Because many constitutive rock properties must be measured at one scale but applied at another, scaling behavior is an issue facing many applied disciplines, including the petroleum industry. A research program has been established to investigate and a quantify scaling behavior through systematic physical experimentation, with the aim of developing and testing models that describe scaling behavior in a quantitative manner. Scaling of constitutive rock properties is investigated through physical experimentation involving the collection of gas-permeability data measured over a range of discrete scales. The approach is to systematically isolate those factors that influence property scaling and investigate their relative contributions to overall scaling behavior. Two blocks of rock, each exhibiting differing heterogeneity structure. have recently been examined. The two samples were found to yield different scaling behavior, as exhibited by changes in the distribution functions and semi-variograms. Simple models have been fit to the measured scaling behavior that are of similar functional form but of different magnitude

  3. Laboratory Investigations of Stratospheric Halogen Chemistry

    Science.gov (United States)

    Wine, Paul H.; Nicovich, J. Michael; Stickel, Robert E.; Hynes, Anthony J.

    1997-01-01

    A final report for the NASA-supported project on laboratory investigations of stratospheric halogen chemistry is presented. In recent years, this project has focused on three areas of research: (1) kinetic, mechanistic, and thermochemical studies of reactions which produce weakly bound chemical species of atmospheric interest; (2) development of flash photolysis schemes for studying radical-radical reactions of stratospheric interest; and (3) photochemistry studies of interest for understanding stratospheric chemistry. The first section of this paper contains a discussion of work which has not yet been published. All subsequent chapters contain reprints of published papers that acknowledge support from this grant.

  4. Quantifying the accuracy of laboratory SIP experimental set ups

    Science.gov (United States)

    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.

  5. Investigating Coccolithophorid Biology in the Sedimentary Laboratory

    Science.gov (United States)

    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.

  6. Experimental investigations of the nuclear structure

    International Nuclear Information System (INIS)

    The problem of experimental investigation into atomic nucleus structure is discussed. Examples of studying the properties of low-lying nucleus states using cyclotron-type accelerators for their production are presented. The consideration is conducted on the base of the Idisol experimental complex created at the Finland. Results of measuring masses of neutron-redundant rubidium nuclei are presented. Schemes of 160Er and 108In decay are presented. 12 refs.; 6 figs

  7. Experimental investigation into Quaternary badland geomorphic development

    Science.gov (United States)

    Kasanin-Grubin, Milica; Kuhn, Nikolaus; Yair, Aaron; Bryan, Rorke; Schwanghart, Wolfgang

    2010-05-01

    Badland morphology is commonly linked to lithological properties of the bedrock. However, recent investigations indicate that the geomorphic development is sensitive to climate and in particular to precipitation characteristics. In this study, the precipitation characteristics that are critical for the Quaternary landscape development in the Dinosaur Badlands in Alberta, Canada, and Zin Valley Badlands, Negev Desert, Israel are investigated. Runoff, erosion and weathering were simulated in the field and the laboratory to determine rates for modeling different precipitation regimes. Currently, the geomorphic development in the Dinosaur badlands is characterized by weathering/supply limited conditions, leading to slope retreat independent of lithology. In the Negev, transport limited conditions cause frequent runoff discontinuity, creating a pattern of areas dominated by erosion or deposition. The results of the weathering and erosion experiments show that the balance between snowmelt induced weathering in the spring and summer rainfall and erosion determine the rate of slope retreat in the Dinosaur Badlands. In the Zin Valley, on the other hand, the magnitude of the individual rainstorms determines whether a slope section is eroded or acts as a sediment sink. The experiments illustrate that the badland slopes experienced an auto-stabilization during the Quaternary in the Zin Valley. In the Dinosaur Badlands Holocene climatic variations have not caused a permanent differentiation of patterns of erosion and deposition. Based on these results the reaction of badland slopes to changing precipitation characteristics was modeled. In their current state, both badland slope systems appear to be fairly stable against climate change in the range of those occurring during the Holocene. However, the stability is achieved in different ways. In the Dinosaur Badlands, weathering rates are low compared to erosion capacity, maintaining continuous evacuation of sediment from slopes to the flood planes of the Red Deer River system. Only a very pronounced contrast between winter weathering and drier summers would generate a colluvium and thus change slope hydrology. In the Zin Valley the development of a thick colluvium at the foot of the slopes has increased infiltration capacity, reducing runoff and sediment yield into the floodplain. Here, only an increase in rainfall magnitude would improve runoff continuity and induce the erosion of the colluvium. This would in turn reduce infiltration capacity and thus initiate a positive feedback on runoff and sediment yield into the Zin River. Overall, Holocene climate change appears to be insufficient to change the geomorphic development in both badlands. However, this stability is achieved not despite of climate, but because of the specific history of geomorphic development. In addition, the combination of erosion and weathering experiments with numerical modeling demonstrates the versatility of Experimental Geomorphology in landscape evolution studies.

  8. Experimental Investigation of Wave Attenuation Through Vegetation

    Science.gov (United States)

    Ozeren, Y.; Wren, D. G.

    2011-12-01

    Wetlands and coastal vegetation can reduce the surge and wave impact on coastal areas. Yet, the primary mechanisms of wave mitigation by vegetation are still unclear. The objective of this study was to investigate and quantify the attenuation of waves through vegetation using laboratory experiments. The wave attenuation properties of artificial vegetation and live and dormant S. alterniflora and J. roemerianus were investigated under monochromatic and irregular wave conditions at full scale in a wave tank facility at the USDA-ARS-National Sedimentation Laboratory in Oxford, Mississippi. Water level sensors and a video camera were used to record water level data. Drag coefficients were estimated for artificial and natural plants and regression equations were derived for the drag coefficients as functions of both Reynolds and Keulegan-Carpenter number. It was observed that vertical variation of vegetation density had an important effect on the drag coefficient.

  9. Experimental investigation of quadrupole virtual photon spectrum

    International Nuclear Information System (INIS)

    To test experimentally the quadrupole virtual photon spectrum calculation, the (e,?) 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 d2?/d?dE 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. Experimental investigation of Reykjavik city footbridge

    DEFF Research Database (Denmark)

    Zivanovic, Stana; Ingólfsson, Einar Thór; Pavic, Aleksandar; Gudmundsson, Gudmundur Valur

    2011-01-01

    This study describes experimental investigation of a 160 m long footbridge in Reykjavik. The bridge is a continuous post tensioned concrete beam spanning eight spans, the longest being 27.1 m. In plan, the structure has eye-catching spiral shape. Modal testing of the structure was conducted to...

  11. Preliminary rock mechanics laboratory: Investigation plan

    International Nuclear Information System (INIS)

    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

  12. Numerical and Experimental Investigation of Tidal Current Energy Extraction

    OpenAIRE

    Sun, Xiaojing

    2008-01-01

    Numerical and experimental investigations of tidal current energy extraction have been conducted in this study. A laboratory-scale water flume was simulated using commercial computational fluid dynamics (CFD) code FLUENT. In the numerical model, the tidal current turbine is represented with an actuator disk, which produces a pressure drop associated with energy loss. The free water surface is considered in the model using a volume of fluid method and is allowed to deform fre...

  13. A Meaningful Experience in Laboratory Investigation

    Science.gov (United States)

    Szinai, S. S.; Szinai, N.

    1976-01-01

    The framework of the course "Problems in Pharmaceutical Chemistry" was used to give second- and third-year pharmacy students at the University of Florida an opportunity to obtain an insight into the workings of laboratories dealing with drug-related problems. Goals, outline, and an illustrative project for the course are described. (LBH)

  14. Experimental investigation of NIRS spatial sensitivity

    OpenAIRE

    Patil, Amol V.; Safaie, Javad; Moghaddam, Hamid Abrishami; Wallois, Fabrice; Grebe, Reinhard

    2011-01-01

    Near infrared spectroscopy (NIRS) is regarded as a potential medical diagnostic technique for investigation of hemodynamic changes. However, uncertainties pertaining to the origin of NIRS signals have hampered its clinical interpretation. The uncertainities in NIRS measurements especially in case of living tissues are due to lack of rigorous combined theoretical-experimental studies resulting in clear understanding of the origin of NIRS signals. For their reliable interpretation it is importa...

  15. Theoretical and experimental investigations on lyoluminescence

    International Nuclear Information System (INIS)

    Investigations on lyoluminescence, a process which emits light when certain substances irradiated with ionizing radiations are dissolved in suitable solvent, have been undertaken to understand the basic physico-chemical mechanism of the process. A theoretical model has been developed utilizing existing schemes and postulates of lyoluminescence for organic substances. To the best knowledge of the authors, no such model exists in the literature. The model is tested for saccharides and is found to fit well with experimental results. (author)

  16. Experimental Emulsified Diesel and Benzen Investigation

    OpenAIRE

    Suleiman Abu-Ein

    2010-01-01

    This study presents an experimental investigation of emulsified fuels as an operating material for vehicle engines. Water in fuel blends is still relatively unknown and unaccepted by the majority of people. Introducing water into the combustion chamber has been around for more than one time, through water injection systems and emulsification of water into fuel. Adding water to fules will reduce bad emissions of the vehicles. It is found that brake power, engine power and also the engine torqu...

  17. Experimental investigation on road vehicle active suspension:

    OpenAIRE

    Jayaraj, Jancirani; John, Dennie; Krishnasamy, Prabu

    2013-01-01

    This paper presents an investigation report for an electronically controlled pneumatic suspension system. The performance improvement in the passengers comfort and attitude behaviour are evaluated for a proportional integral derivative (PID) controlled pneumatic suspension design. An appropriate mathematical model is developed for a single wheel suspension with the passenger seat system. The simulation is accomplished through LABVIEW and lab-based experimental analysis is conducted. Based on ...

  18. Experimental investigation on road vehicle active suspension

    OpenAIRE

    Krishnasamy, Prabu; Jayaraj, Jancirani; John, Dennie

    2015-01-01

    This paper presents an investigation report for an electronically controlled pneumatic suspension system. The performance improvement in the passengers comfort and attitude behaviour are evaluated for a proportional integral derivative (PID) controlled pneumatic suspension design. An appropriate mathematical model is developed for a single wheel suspension with the passenger seat system. The simulation is accomplished through LABVIEW and lab-based experimental analysis is conducted. Based on ...

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

    Science.gov (United States)

    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 analysis, numerical modelling, and joint development and standardization of numerical tools (e-science implementation); 6) collect and store data in a flexible inventory database accessible within and beyond the Earth Sciences community(open access and outreach); 7) connect to environmental and hazard protection agencies, stakeholders, and public to raise consciousness of geo-hazards and geo-resources (innovation for society). We will inform scientists and industrial stakeholders on the most recent WG6 achievements in EPOS and we will show how our community is proceeding to design the thematic core services.

  20. An experimental investigation of parasitic microstrip arrays

    Science.gov (United States)

    Lee, Richard Q.; Acosta, Roberto; Dahele, J. S.; Lee, K. F.

    1987-01-01

    The characteristics of a parasitic microstrip antenna array with a center-fed patch are experimentally investigated. The parasitic array is composed of identical parasitic patches which are symmetrically arranged and electromagnetically coupled to a center-fed patch. The shape and dimensions of the parasitic patches and their positions relative to the center-fed patch are parameters in the study. To show mutual coupling effects between radiating and nonradiating edges of adjacent patches, the impedance and radiation characteristics of a three-element parasitic array excited with (0.1) mode are examined, and compared to that of a single patch. Experimental data indicate that the presence of parasitic patches has significant effects upon the gain, resonant frequency, and impedance bandwidth of the array.

  1. The Locust Jump: An Integrated Laboratory Investigation

    Science.gov (United States)

    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…

  2. Experimental Emulsified Diesel and Benzen Investigation

    Directory of Open Access Journals (Sweden)

    Suleiman Abu-Ein

    2010-05-01

    Full Text Available This study presents an experimental investigation of emulsified fuels as an operating material for vehicle engines. Water in fuel blends is still relatively unknown and unaccepted by the majority of people. Introducing water into the combustion chamber has been around for more than one time, through water injection systems and emulsification of water into fuel. Adding water to fules will reduce bad emissions of the vehicles. It is found that brake power, engine power and also the engine torque have been improved with the emulsified fuels for both diesel and benzen till 25% water percentage addition.

  3. Laboratory investigations of volatile trapping in comets

    Science.gov (United States)

    Owen, Tobias (Principal Investigator)

    1996-01-01

    This research program consists of laboratory studies of the formation of ice at low temperatures to simulate the formation of comets in the outer solar nebula. The ice is condensed in the presence of various mixtures of gases at a given temperature, and then warmed to see at what temperatures the gases are released and how much gas was actually trapped. Our results to date indicate that the trapping of argon, krypton, and xenon in ice formed at approximately 50 K fractionates these gase in a way that fits the relative abundances found in the atmospheres of Mars and Earth. This is markedly different from the situation in chondritic meteorites, where the abundance of xenon is about equal to that of krypton. It appears that comets represent a better source for planetary volatiles than do the meteorites.

  4. Experimental and numerical investigations of plasma turbulence

    International Nuclear Information System (INIS)

    Turbulence in plasmas has been investigated experimentally and numerically. The work described here is divided into four parts: - experiments on edge turbulence in a single-ended Q-machine. Convective cells are investigated in detail together with the anomalous transport caused by them. - Numerical simulation of the edge turbulence in the Q-machine. This simulation uses spectral methods to solve Euler's equation in a cylindrical geometry. - Measurements on wave propagation and the ion beam instability in an unmagnetized plasma with an ion beam with a finite diameter. - Development of software for the automated acquisition of data. This program can control an experiment as well as make measurements. It also include a graphics part. (author) 66 ills., 47 refs

  5. Experimental Investigation of Shock Wave Surfing

    CERN Document Server

    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.

  6. Investigating intertemporal choice through experimental evolutionary robotics.

    Science.gov (United States)

    Paglieri, Fabio; Parisi, Domenico; Patacchiola, Massimiliano; Petrosino, Giancarlo

    2015-06-01

    In intertemporal choices, subjects face a trade-off between value and delay: achieving the most valuable outcome requires a longer time, whereas the immediately available option is objectively poorer. Intertemporal choices are ubiquitous, and comparative studies reveal commonalities and differences across species: all species devalue future rewards as a function of delay (delay aversion), yet there is a lot of inter-specific variance in how rapidly such devaluation occurs. These differences are often interpreted in terms of ecological rationality, as depending on environmental factors (e.g., feeding ecology) and the physiological and morphological constraints of different species (e.g., metabolic rate). Evolutionary hypotheses, however, are hard to verify in vivo, since it is difficult to observe precisely enough real environments, not to mention ancestral ones. In this paper, we discuss the viability of an approach based on evolutionary robotics: in Study 1, we evolve robots without a metabolism in five different ecologies; in Study 2, we evolve metabolic robots (i.e., robots that consume energy over time) in three different ecologies. The intertemporal choices of the robots are analyzed both in their ecology and under laboratory conditions. Results confirm the generality of delay aversion and the usefulness of studying intertemporal choice through experimental evolutionary robotics. PMID:25721533

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

    Science.gov (United States)

    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.

  8. Experimental investigations of MFCI in Russia

    International Nuclear Information System (INIS)

    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 water. Some review is given on the further program of the MFCI study. (author)

  9. Experimental Investigation of Pseudospark generated electron beam

    International Nuclear Information System (INIS)

    The pseudospark (PS) discharge is, however, more recently recognized as a different type of discharge which is capable of generating electron beams with the highest combined current density and brightness of any known type of electron source. PS discharge is a specific type of gas discharge, which operates on the left-hand side of the hollow cathode analogy to the Paschen curve with axially symmetric parallel electrodes and central holes on the electrodes. The PS discharge generated electron beam has tremendous applications in plasma filled microwave sources where normal material cathode cannot be used. Analysis of the electron beam profile has been carried out experimentally for different applied voltages. The investigation has been done at different axial and radial location inside the drift tube in argon atmosphere. This paper represents experimentally derived axial and radial variation of the beam current inside the plasma filled drift tube of PS discharge based plasma cathode electron (PCE) gun. With the help of current density estimation the focusing and defocusing point of electron beam in axial direction can be analyzed. It has been further confirmed the successful propagation of electron beam in confined manner without any assistance of external magnetic field.

  10. Experimental Investigation of Pseudospark generated electron beam

    Science.gov (United States)

    Kumar, Niraj; Verma, D. K.; Prajapati, J.; Kumar, M.; Meena, B. L.; Tyagi, M. S.; Srivastava, V.; Pal, U. N.

    2012-11-01

    The pseudospark (PS) discharge is, however, more recently recognized as a different type of discharge which is capable of generating electron beams with the highest combined current density and brightness of any known type of electron source. PS discharge is a specific type of gas discharge, which operates on the left-hand side of the hollow cathode analogy to the Paschen curve with axially symmetric parallel electrodes and central holes on the electrodes. The PS discharge generated electron beam has tremendous applications in plasma filled microwave sources where normal material cathode cannot be used. Analysis of the electron beam profile has been carried out experimentally for different applied voltages. The investigation has been done at different axial and radial location inside the drift tube in argon atmosphere. This paper represents experimentally derived axial and radial variation of the beam current inside the plasma filled drift tube of PS discharge based plasma cathode electron (PCE) gun. With the help of current density estimation the focusing and defocusing point of electron beam in axial direction can be analyzed. It has been further confirmed the successful propagation of electron beam in confined manner without any assistance of external magnetic field.

  11. Experimental Investigations of the Lunar Photoelectron Sheath

    Science.gov (United States)

    Dove, A.; Sternovsky, Z.; Wang, X.; Robertson, S. H.; Lapanse, C.; Horanyi, M.; Collette, A.

    2010-12-01

    Solar ultraviolet radiation incident upon the dayside lunar surface produces a photoelectron gas that dominates the near-surface plasma environment, with a typical density of 60 cm-3 and a characteristic scale-length of ~1 m. It has traditionally been difficult to produce a photoelectron gas with sufficient density in a laboratory settings to study its properties. In our initial experiments, the characterization of the photoelectron density above a Zr surface (work function W=4.4 eV) illuminated by Xe excimer lamps (peak emission at a wavelength of 172 nm) indicated that a sheath with a Debye length on the order of 10 cm formed. We characterize the photoelectron population above the surface by utilizing an emissive probe to map the electric potential distribution above the surface, and a Langmuir probe to determine the number density and temperature of the photoelectrons. A grid is placed 7.5 cm above the Zr surface to repel photoelectrons emitted from the chamber walls. Emissive probe measurements show a potential dip of about 2 V extending ~1 cm above the zirconium surface. The size of this potential well is dependent on the number of lamps illuminating the surface, as the density of photoelectrons above the surface increases with greater illumination. The electrons in the sheath have a Maxwellian distribution with an electron temperature around 1 eV (maximum energies are expected to be approximately 2.8 eV). We will use this experimental apparatus to characterize the photoelectron sheath above other surfaces; powders, such as CeO2 have similar work functions, but different photoelectric yields. Lunar soil simulants are expected to have approximately an order of magnitude smaller yield than metallic surfaces, which will act to increase the characteristic length of the photoelectron sheath above the surface. The experiments and accompanying computer simulations are used to guide the development of new instrument concepts for future in situ plasma measurements on the lunar surface.

  12. Experimental investigation on reflooding of debris beds

    International Nuclear Information System (INIS)

    Highlights: • A downcomer can significantly improve the beds’ coolability. • The perforated downcomer was occupied by steam and thus without effect. • Comparable quenching times in DEBRIS and PRELUDE. • Good agreement of MEWA calculation with the experiment in case of open downcomer. - Abstract: In case of a severe accident, continuous unavailability of cooling water to the core may result in over heating of the fuel elements and the loss of core integrity. Under such conditions a structure of heated particles of different sizes and shapes (debris) may be formed by fragmentation of core material inside the reactor pressure vessel (RPV). To avoid any damage to the RPV the reflooding is of great importance in order to establish long-term coolability. In the framework of an GRS R and D project and the SARNET network, specific experimental investigations on the coolability of debris beds with different bed contents (e.g. mono-/polydispersed bed of stainless steel balls with 6/3/2 mm in diameter, irregularly shaped particles from PREMIX experiments – KIT) and various initial bed temperatures at ambient pressure (1 bar) were carried out at IKE using the DEBRIS test facility and the small DEBRIS test set-up. In both experimental configurations the particles are volumetrically heated by an electromagnetic induction coil to predefined temperatures and then flooded with subcooled water from top (top-flooding) or from bottom (bottom-flooding). Depending on the flooding situation the cooling down (quenching) behaviour of the beds varies significantly due to the change of co- and counter-current liquid–vapour flow and respective heat transfer between solid and generated two-phase flow. This paper presents the main experimental results of systematic quenching studies at IKE. Furthermore, some representative results of benchmark experiments performed by IKE and IRSN (PRELUDE test facility) in the frame of the SARNET joint work are demonstrated. Finally, exemplary comparisons between experimental data and numerical results of simulations with IKE’s code MEWA-2D are shown

  13. Mars Science Laboratory Mission and Science Investigation

    Science.gov (United States)

    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-bearing strata, separated by an unconformity from overlying likely anhydrous strata; the landing ellipse is characterized by a mixture of alluvial fan and high thermal inertia/high albedo stratified deposits; and a number of stratigraphically/geomorphically distinct fluvial features. Samples of the crater wall and rim rock, and more recent to currently active surface materials also may be studied. Gale has a well-defined regional context and strong evidence for a progression through multiple potentially habitable environments. These environments are represented by a stratigraphic record of extraordinary extent, and insure preservation of a rich record of the environmental history of early Mars. The interior mountain of Gale Crater has been informally designated at Mount Sharp, in honor of the pioneering planetary scientist Robert Sharp. The major subsystems of the MSL Project consist of a single rover (with science payload), a Multi-Mission Radioisotope Thermoelectric Generator, an Earth-Mars cruise stage, an entry, descent, and landing system, a launch vehicle, and the mission operations and ground data systems. The primary communication path for downlink is relay through the Mars Reconnaissance Orbiter. The primary path for uplink to the rover is Direct-from-Earth. The secondary paths for downlink are Direct-to-Earth and relay through the Mars Odyssey orbiter. Curiosity is a scaled version of the 6-wheel drive, 4-wheel steering, rocker bogie system from the Mars Exploration Rovers (MER) Spirit and Opportunity and the Mars Pathfinder Sojourner. Like Spirit and Opportunity, Curiosity offers three primary modes of navigation: blind-drive, visual odometry, and visual odometry with hazard avoidance. Creation of terrain maps based on HiRISE (High Resolution Imaging Science Experiment) and other remote sensing data were used to conduct simulated driving with Curiosity in these various modes, and allowed selection of the Gale crater landing site which requires climbing the base of a mountain to achieve its primary science goals. The Sample Acquisition, Processing, and Handling (SA/SPaH) subsystem is responsible for the acquisition of rock and soil samples from the Martian surface and the processing of these samples into fine particles that are then distributed to the analytical science instruments. The SA/SPaH subsystem is also responsible for the placement of the two contact instruments (APXS, MAHLI) on rock and soil targets. SA/SPaH consists of a robotic arm and turret-mounted devices on the end of the arm, which include a drill, brush, soil scoop, sample processing device, and the mechanical and electrical interfaces to the two contact science instruments. SA/SPaH also includes drill bit boxes, the organic check material, and an observation tray, which are all mounted on the front of the rover, and inlet cover mechanisms that are placed over the SAM and CheMin solid sample inlet tubes on the rover top deck.

  14. Modelling and laboratory investigation of microbial enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    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

  15. Experimental and Theoretical Investigations of Wet Flue Gas Desulphurisation

    DEFF Research Database (Denmark)

    Kiil, Søren

    This thesis describes experimental and theoretical investigations of wet flue gas desulphurisa-tion (FGD). A review of the current knowledge of the various rate determining steps in wet FGD plants is presented. The experimental work covers laboratory studies as well as pilot- and full...... was found to decrease the rate of gas phase mass transport with up to 15 %, though the effect could not be correlated.A detailed model for a wet FGD pilot plant, based on the falling film principle, was devel-oped. All important rate determining steps, absorption of SO2, oxidation of HSO3...... absorber de-pending on the process conditions. A typical holding tank pH of 5-5.5 (also used in full-scale wet FGD packed towers) was found to be a reasonable compromise between residual lime-stone in the gypsum and the degree of desulphurisation. Simulations were only slightly sensi-tive to the...

  16. Experimental investigation of creep behavior of reactor vessel lower head

    International Nuclear Information System (INIS)

    The objective of the USNRC supported Lower Head Failure (LHF) Experiment Program at Sandia National Laboratories is to experimentally investigate and characterize the failure of the reactor pressure vessel (RPV) lower head due to the thermal and pressure loads of a severe accident. The experimental program is complemented by a modeling program focused on the development of a constitutive formulation for use in standard finite element structure mechanics codes. The problem is of importance because: lower head failure defines the initial conditions of all ex-vessel events; the inability of state-of-the-art models to simulate the result of the TMI-II accident (Stickler, et al. 1993); and TMI-II results suggest the possibility of in-vessel cooling, and creep deformation may be a precursor to water ingression leading to in-vessel cooling

  17. Numerical and Experimental Investigation on Root Anchorage

    Science.gov (United States)

    Ali, F.; Osman, N.; Hashim, R.; Khalilnejad, A.

    2012-04-01

    In more recent times, the roles played by vegetation in some specific geotechnical processes have been recognized. Vegetation may affect slope stability in many ways. The stability of slopes is governed by the load, which is the driving force that causes failure, and the resistance, which is the strength of the soil-root system. The weight of trees growing on a slope adds to the load but the roots of trees serve as a soil reinforcement and increase the resistance. In order to ensure that the weight of the trees on the slope help to enhance its stability it is required that they are planted down-slope of the neutral point. Maximum contribution is produced if the trees are located at the slope toe. Considering a typical slip circle, at this location the direction of shear force acting on the trees may be considered as close-to-vertical for the purpose of analysis. In this study, 3D numerical simulations of root anchorage have been performed to study the mechanism and the factors influencing the pull out capacity of tree roots. The investigation was performed using ABACUS finite element program. Field pull-out tests were also carried out on Melastoma malabathricum which been shown to be very suitable to be grown on slope, and the results are compared with numerical simulations. Parametric studies were also done to study the effects of factors such as root pattern, angle of inclination as well as soil properties. The results show that the 3D finite element analyses are able to approximately simulate the experimental tests. The results of the field tests, simulations and the parametric studies will be presented and discussed in more details in this paper.

  18. Numerical and experimental investigation of downdraft gasification of wood chips

    International Nuclear Information System (INIS)

    Highlights: ? We examined the efficiency of gasifying wood chips in a downdraft reactor using numerical and experimental methods. ? Feedstock density and heating value is important as it controls the flame stability. ? Improvements modeled gasifier include decreasing the heat losses, controlling the system leaks and enhancing the mixing. ? Max. temp. measured at the combustion zone as expected with a cold gas efficiency of 70% (CFD) vs. 89% (equilibrium model). - Abstract: Biomass is widely perceived as a potential renewable energy source. Thermo-chemical conversion technologies including gasification, co-firing, and pyrolysis are of primary interest due to their higher conversion efficiency and throughput when compared with the low temperature digestion and fermentation for lignocellulose and wood-based feedstock. In this paper, a small scale, air blown, downdraft gasification system is operated using wood to investigate its conversion efficiency. Wood chips of 0.5 cm thickness, 1–2 cm width, and 2–2.5 cm length constitute the feedstock to the downdraft gasifier that is assembled and instrumented at Masdar Institute’s Waste-to-Energy laboratory. The experimental investigation of the temperature field inside the gasifier is followed by high fidelity numerical simulation using CFD to model the Lagrangian particle coupled evolution. The numerical simulation is conducted on a high resolution mesh accounting for the solid and gaseous phases, k–? turbulence, and reacting CFD model. The temperature distribution and the evolution of species are computed and compared with the experimental results and with the ideal equilibrium, zero dimensional case.

  19. Experimental investigation of a coaxial gyrotron oscillator

    Science.gov (United States)

    Advani, Rahul N.

    1999-09-01

    This thesis presents experimental results of a megawatt power level, 140 GHz coaxial gyrotron oscillator. The coaxial gyrotron has the potential to transport very high power electron beams and thus achieve higher microwave output power levels than conventional gyrotrons. A TE21,13 coaxial gyrotron was designed to operate at 95 kV, 76 A. This tube was tested to high power with the first high power Inverted Magnetron Injection Gun (IMIG). The IMIG electron gun was tested to 10 MW (105 kV, 93 A), which is the highest power level for a non-relativistic gyrotron gun. Operation of the coaxial gyrotron oscillator yielded power levels of greater than 1 MW in two different configurations: with the coaxial conductor (at 92kV, 70 A, and 16% efficiency) and without the coaxial conductor (85 kV, 65 A, and 18% efficiency). We also successfully operated this tube in three configurations (empty cavity, radial output, and axial output) with no beam interception. We observed regimes of dominant single mode and multi-mode operation. We also identified electron beam asymmetries and tube alignment as two major issues, which can limit the performance of a coaxial gyrotron. An unexpected source of magnetic field error was found in the magnetization of the stainless steel parts. All these results have led to techniques for improving not only coaxial gyrotrons but also other gyrotron tubes. We also investigated a ferroelectric cathode, which has the potential to achieve higher currents than thermionic cathodes in a simpler, low cost gun. We report the first results on a ferroelectric cathode gun in a magnetron injection gun configuration suitable for use in a gyrotron. It had an annular emitter shape with a diameter of 11.4 cm and a width of 0.25 cm and operated at currents of up to 10 A (1.1 A/cm2) at 8 kV, in 5 ?s flat-top pulses. This result (along with the kiloampere beam obtained at Integrated Applied Physics) demonstrate the scalability of ferroelectric cathodes to large diameter electron beams. Also, the first ever microwaves from a ferroelectric cathode were generated in a collaboration experiment at Tel Aviv University. Finally, we developed a theory to explain the emission process from ferroelectric cathodes. The experiments reported have shown the suitability of ferroelectric cathodes for future microwave generation experiments. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

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

    Science.gov (United States)

    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…

  1. Experimental investigation of the plasma focus discharge

    International Nuclear Information System (INIS)

    One reports the main experimental results obtained on low current level Focus discharges: 200 kA and 50 kA. Neutron and X-ray scaling laws from 50 kA up to 2500 kA have been established by taking into account all the results obtained at the Centre d'Etudes de Limeil. These scaling laws show the great interest of a 10 MA Plasma Focus device. To achieve this high current level, one present the experimental study of an explosive current generator driven plasma Focus

  2. An Experimental Investigation of Cognitive Defusion

    Science.gov (United States)

    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…

  3. Experimental Explosive Characterization for Counterterrorist Investigation

    Science.gov (United States)

    Etayo, D.; Maestrojuan, I.; Teniente, J.; Ederra, I.; Gonzalo, R.

    2013-08-01

    A THz spectral characterization of different explosives of special interest for the Spanish National Security Forces "Guardia Civil" is presented in this paper. This forensic analysis has been done in the frequency range from 0.060 THz to 3.5 THz using the Teraview TPS Spectra 3000 system in laboratory conditions. With this equipment the refractive index, absorbance and complex permittivity of the explosive samples have been obtained. In this study, some of the most common used explosives (Bullet gunpowder, mine gunpowder, PETN, TNT, RDX) are analysed paying special attention to differences related to the manufacturing process used to elaborate some of them and to the purity of the samples. The different fabrication processes of the explosives lead to the same spectral behaviour and characteristics. At the same time, the inclusion of some additives in the explosive samples does not alter their main electromagnetic properties. The sensitivity limit of the measurement system has been found to be to 10 mg of explosives. These results will be used to design future THz imaging systems that allow to detect and identify them in security and defence applications and/or to complete laboratory studies after a terrorist action.

  4. Experimental Investigation on Caisson Breakwater Sliding

    DEFF Research Database (Denmark)

    Ruol, Piero; Martin, Paolo; Andersen, Thomas Lykke; Martinelli, Luca

    This note presents wave flume experiments, carried out at Aalborg University, measuring the horizontal sliding distance of a vertical breakwater in 1:40 scale. Horizontal and uplift wave induced pressures were accurately measured simultaneously with the caisson movements. Caissons of different...... weight and same geometries are tested under regular and irregular waves. It is found that, under breaking conditions, the expected inaccuracy of the prediction of the force, inherent on the variability of the breaking process, induce unacceptable errors in the prediction of the sliding. This observation...... endorses other previous experimental results. Conversely, when the actual measured input force is used as input, the analytical Shimosako formula fit quite well the experimental sliding distance....

  5. Numerical and experimental investigations on cavitation erosion

    Science.gov (United States)

    Fortes Patella, R.; Archer, A.; Flageul, C.

    2012-11-01

    A method is proposed to predict cavitation damage from cavitating flow simulations. For this purpose, a numerical process coupling cavitating flow simulations and erosion models was developed and applied to a two-dimensional (2D) hydrofoil tested at TUD (Darmstadt University of Technology, Germany) [1] and to a NACA 65012 tested at LMH-EPFL (Lausanne Polytechnic School) [2]. Cavitation erosion tests (pitting tests) were carried out and a 3D laser profilometry was used to analyze surfaces damaged by cavitation [3]. The method allows evaluating the pit characteristics, and mainly the volume damage rates. The paper describes the developed erosion model, the technique of cavitation damage measurement and presents some comparisons between experimental results and numerical damage predictions. The extent of cavitation erosion was correctly estimated in both hydrofoil geometries. The simulated qualitative influence of flow velocity, sigma value and gas content on cavitation damage agreed well with experimental observations.

  6. Experimental investigation of bifurcation induced bandgap reconfiguration

    Science.gov (United States)

    Bernard, Brian P.; Mazzoleni, Michael J.; Garraud, Nicolas; Arnold, David P.; Mann, Brian P.

    2014-08-01

    By applying an asymmetric on-site restoring force in a 1D chain of oscillators, we demonstrate experimentally that a morphing in the bandgap structure or passive bandgap reconfiguration can be triggered by an increase in environmental excitation amplitude. Recent studies on wave propagation have focused on new capabilities and behaviors resulting from intrinsic nonlinearities. This paper details a bistable experimental design that achieves amplitude dependent filtering through passive bandgap reconfiguration, which is triggered by a bifurcation. The system studied comprises a 1D chain of axially aligned pendulums in dimer unit cells with geometrically nonlinear nearest neighbor coupling where bistability is induced through repulsive magnets. When the bistability is asymmetric, each potential well has a different linear spectra. Though this paper uses mechanically coupled oscillators as an example, the phenomenon itself could be used in any wave propagation media where asymmetric bistability can be implemented.

  7. Numerical and experimental investigations on cavitation erosion

    International Nuclear Information System (INIS)

    A method is proposed to predict cavitation damage from cavitating flow simulations. For this purpose, a numerical process coupling cavitating flow simulations and erosion models was developed and applied to a two-dimensional (2D) hydrofoil tested at TUD (Darmstadt University of Technology, Germany) [1] and to a NACA 65012 tested at LMH-EPFL (Lausanne Polytechnic School) [2]. Cavitation erosion tests (pitting tests) were carried out and a 3D laser profilometry was used to analyze surfaces damaged by cavitation [3]. The method allows evaluating the pit characteristics, and mainly the volume damage rates. The paper describes the developed erosion model, the technique of cavitation damage measurement and presents some comparisons between experimental results and numerical damage predictions. The extent of cavitation erosion was correctly estimated in both hydrofoil geometries. The simulated qualitative influence of flow velocity, sigma value and gas content on cavitation damage agreed well with experimental observations.

  8. Experimental Investigation on Caisson Breakwater Sliding

    DEFF Research Database (Denmark)

    Ruol, Piero; Martin, Paolo

    2014-01-01

    This note presents wave flume experiments, carried out at Aalborg University, measuring the horizontal sliding distance of a vertical breakwater in 1:40 scale. Horizontal and uplift wave induced pressures were accurately measured simultaneously with the caisson movements. Caissons of different weight and same geometries are tested under regular and irregular waves. It is found that, under breaking conditions, the expected inaccuracy of the prediction of the force, inherent on the variability of the breaking process, induce unacceptable errors in the prediction of the sliding. This observation endorses other previous experimental results. Conversely, when the actual measured input force is used as input, the analytical Shimosako formula fit quite well the experimental sliding distance.

  9. Experimental investigation of radiation temperature in hohlraums

    International Nuclear Information System (INIS)

    Radiation temperature in hohlraums is diagnosed by using two soft X-ray spectrometers and a multi-pinhole soft X-ray streak camera. Taking plasma closure effects of the diagnostic hole into consideration, the accuracy has been improved. 2D-images and processes of the hole closure and radiation temperature in the hohlraums vs time have been obtained. A preliminary model of the closure effect of diagnostic hole is proposed based on the experimental data

  10. Experimental investigations of active air bearings

    DEFF Research Database (Denmark)

    Santos, Ilmar; Morosi, Stefano

    2012-01-01

    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 i...

  11. Role of vegetation on erosion processes: experimental investigation

    Science.gov (United States)

    Termini, Donatella

    2014-05-01

    Investigations on soil-system ecology are ever more oriented toward quantitative information based on the study of the linkages between physical processes and ecological response in rivers. As it is known, in presence of vegetation, the hydrodynamics characteristics of flow are principally determined by the mutual interrelation between the flow velocity field and the hydraulic behavior (completely submerged or emergent) of the vegetation elements. Much effort has been made toward identifying the theoretical law to interpret the vertical profile of flow longitudinal velocity in vegetated channels. Many theoretical and experimental studies in laboratory channels have been carried out and especially the case of submerged flexible vegetation has been examined (Termini, 2012). The effects of vegetation on flow velocity are significant and of crucial importance for stabilizing sediments and reducing erosion. Vegetation has a complex effect on walls roughness and the study of the hydrodynamic conditions of flow is difficult. Although most studies based on the "boundary layer" scheme so that the hydrodynamic conditions inside and above the vegetated layer are considered separately, some authors (Ghisalberti and Nepft, 2002; Carollo et al., 2008) claim that the "mixing layer" scheme is more appropriate to define the velocity profile both inside and outside the vegetated layer. Experimental program has been recently carried out in two laboratory flumes constructed at the laboratory of Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali - University of Palermo (Italy) with real and flexible vegetation on the bed. In this paper, attention is paid to the influence of vegetation on the erosion processes both on the bed and on the channel banks. The structure of the detailed flow velocity field is analyzed and compared with that obtained in absence of vegetation. Attention is then devoted to the analysis of soil erosion mechanism. Carollo F.G., Ferro V., Termini D. (2008). Flow velocity profile and turbulence characteristics in a vegetated straight flume. International Congress Riverflow 2008- Cesnme - Izmir (Turkey) 3-5 September Ghisalberti, M. & Nepf, H. M. 2002. Mixing layer and coherent structures in vegetated acquatic flows. Journal of Geophysical Reseach 107(2). Termini D. (2012). Experimental investigation on the role of vegetation on sediment transport mechanism: review of recent results - 9th ISE - International Symposium on Ecohydraulics - 2012, ISSN 0945-358X Vienna - CD proceedings-

  12. Experimental investigation of cryogenic oscillating heat pipes.

    Science.gov (United States)

    Jiao, A J; Ma, H B; Critser, J K

    2009-07-01

    A novel cryogenic heat pipe, oscillating heat pipe (OHP), which consists of an 4 × 18.5 cm evaporator, a 6 × 18.5 cm condenser, and 10 cm length of adiabatic section, has been developed and experimental characterization conducted. Experimental results show that the maximum heat transport capability of the OHP reached 380W with average temperature difference of 49 °C between the evaporator and condenser when the cryogenic OHP was charged with liquid nitrogen at 48% (v/v) and operated in a horizontal direction. The thermal resistance decreased from 0.256 to 0.112 while the heat load increased from 22.5 to 321.8 W. When the OHP was operated at a steady state and an incremental heat load was added to it, the OHP operation changed from a steady state to an unsteady state until a new steady state was reached. This process can be divided into three regions: (I) unsteady state; (II) transient state; and (III) new steady state. In the steady state, the amplitude of temperature change in the evaporator is smaller than that of the condenser while the temperature response keeps the same frequency both in the evaporator and the condenser. The experimental results also showed that the amplitude of temperature difference between the evaporator and the condenser decreased when the heat load increased. PMID:20585410

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

    DEFF Research Database (Denmark)

    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....

  14. Experimental investigation of quantum Simpson's paradox

    Science.gov (United States)

    Li, Yu-Long; Tang, Jian-Shun; Wang, Yi-Tao; Wu, Yu-Chun; Han, Yong-Jian; Li, Chuan-Feng; Guo, Guang-Can; Yu, Ying; Li, Mi-Feng; Zha, Guo-Wei; Ni, Hai-Qiao; Niu, Zhi-Chuan

    2013-07-01

    The well-known Simpson's paradox, or Yule-Simpson (YS) effect, is often encountered in social-science and medical-science statistics. It occurs when the correlations present in different groups are reversed if the groups are combined. Simpson's paradox also exists in quantum measurements. In this Brief Report, we experimentally realized two analogous effects: the quantum-classical YS effect and the quantum-quantum YS effect in the quantum-dot system. We also compared the probability of obtaining those two effects under identical quantum measurements and found that the quantum-quantum YS effect is more likely to occur than the quantum-classical YS effect.

  15. EXPERIMENTAL INVESTIGATION OF LIGHTWEIGHT CONCRETE WITH STEELFIBER

    Directory of Open Access Journals (Sweden)

    Fatih ALTUN

    2006-03-01

    Full Text Available In this study, Dramix RC-80/60-BN steel fiber was added into lightweight concrete of 400 cement dosage in the amounts of 10, 20, 30, 40, 50 and 60. The specimens were tested 28 days later to find the measured apparent specific gravity, concrete strength, modulus of elasticity and toughness value experimentally. Our study concluded that the addition of steel fiber has not changed the concrete strength and modulus of elasticity while it has increased the toughness of lightweight concrete of fixed cement dosage.

  16. Experimental investigations of active air bearings

    DEFF Research Database (Denmark)

    Santos, Ilmar; Morosi, Stefano

    -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....... Implementing active lubrication adds however a considerable number of parameters and variables. The performance of a good control system lays most importantly on a good choice of control gains, which in general are different depending on the goal of the controller. Optimum tuning of the control loop is...

  17. Numerical and experimental investigations on catalytic recombiners

    International Nuclear Information System (INIS)

    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)

  18. Experimental analysis of nonlinear oscillations in the undergraduate physics laboratory

    International Nuclear Information System (INIS)

    In this paper, we present a simple experiment to introduce the nonlinear behaviour of oscillating systems in the undergraduate physics laboratory. The transverse oscillations of a spring allow reproduction of three totally different scenarios: linear oscillations, nonlinear oscillations reducible to linear for small displacements, and intrinsically nonlinear oscillations. The chosen approach consists of measuring the displacements using video photogrammetry and computing the velocities and the accelerations by means of a numerical differentiation algorithm. In this way, one can directly check the differential equation of the motion without having to integrate it, or perform an experimental study of the potential energy in each of the analysed scenarios. This experiment allows first year students to reflect on the consequences and the limits of the linearity assumption for small displacements that is so often made in technical studies. (paper)

  19. Overall control architecture of the European tritium handling experimental laboratory

    International Nuclear Information System (INIS)

    The overall control architecture serving the European Tritium Handling Experimental Laboratory (ETHEL) consists of two types of apparatus: (1) Programmable Logic Controllers (PLCs), Personal Computers (PCs), networks which constitute the so-called Distributed Digital Control System (DDCS); (2) Fail-safe hard-wiring which operates independently of the DDCS. This paper deals with the first type of apparatus; its hardware and software are described. The computerized system, defined by a four-level hierarchical and modular architecture, is a large distributed Real-time Control System. The operation is mainly centralised in the Control Room through a fully programmable man-machine interface (graphic displays, trends, etc.). 3 refs., 3 figs., 1 tab

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

    Science.gov (United States)

    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…

  1. A Research-Inspired Laboratory Sequence Investigating Acquired Drug Resistance

    Science.gov (United States)

    Taylor, Elizabeth Vogel; Fortune, Jennifer A.; Drennan, Catherine L.

    2010-01-01

    Here, we present a six-session laboratory exercise designed to introduce students to standard biochemical techniques in the context of investigating a high impact research topic, acquired resistance to the cancer drug Gleevec. Students express a Gleevec-resistant mutant of the Abelson tyrosine kinase domain, the active domain of an oncogenic…

  2. Experimental investigations of active air bearings

    DEFF Research Database (Denmark)

    Santos, Ilmar; Morosi, Stefano

    2012-01-01

    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 traditional gas lubrication: 1) Low damping makes operation across critical speed dangerous, as even low level of unbalance can generate large vibration responses. This is especially problematic for gas bearing applications, which often operate in the supercritical region. Moreover, 2) An upper bound to supercritical operation is determined by the appearance of subsynchronous whirl instability. Due to the sudden increase in amplitude with respect to speed, this most often corresponds to the maximal attainable rotational speed of the system. Postponing the onset speed of instability poses therefore one of the 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 properties of the bearings, however issues related to the manufacturing and accuracy of predictions has so far limited their applications. Another drawback is that passive bearings offer a low degree of flexibility, meaning that an accurate optimization is necessary for each application. The developed prototype active bearing offers several promising performance enhancements. Synchronous vibrations can be effectively addressed ensuring safe operation across the critical speeds; whirling instability is suppressed; interveningon the software, rather than the hardware can modify the response of the system. Implementing active lubrication adds however a considerable number of parameters and variables. The performance of a good control system lays most importantly on a good choice of control gains, which in general are different depending on the goal of the controller. Optimum tuning of the control loop is addressed experimentally, showing dependency on the supply pressure and, less prominently, the rotational velocity. Copyright © 2012 by ASME.

  3. Experimental investigation of wing with vortex generators

    Directory of Open Access Journals (Sweden)

    ?.?. ???????

    2010-01-01

    Full Text Available  The idea of research of the organized vortex flow of a wing for the purpose of perfection of aerodynamic characteristics on the big angels of attack develops. The wing with vortex generators in the form of flows on a forward edge in low velocity wind tunnel was with that end in view investigated. It is shown, that the organized vortex flow of a wing with vortex generators on a forward edge practically does not change aerodynamic characteristics at small angels of attack and strongly influences on the big angels of attack, increasing the maximum elevating force and improving momentum characteristics at small change of drag.

  4. Experimental Investigation of Using Fuel Additives - Alcohol

    OpenAIRE

    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 ...

  5. Experimental research of soil erosion using laboratory rainfall simulator

    Science.gov (United States)

    Laburda, Tomáš; Schwarzová, Pavla; Krása, Josef

    2015-04-01

    Soil erosion has been an important part of research at the Department of Irrigation, Drainage and Landscape Engineering, Czech Technical University in Prague since the 50s of the 20th century. Bigger emphasis was put later on practical methods resulting in acquisition of laboratory rainfall simulator in 1999. This article compares data from simulations done at the laboratory rainfall simulator which is used for experimental measurement of rainfall-runoff processes on soil samples (typical soil type groups) from agriculture land in the Czech Republic. Total 10 soil sets have been tested within 255 simulations (247 rainfall-runoff hours in total) from 2002 to 2014. These soil sets cover wide range of soil types from silty clay loam to sandy loam soils or from impervious to pervious soils. Setting values of rainfall intensity (40 to 60 mm/hr), inclination (longitudinal slope from 4° to 8°) and initial condition of surface runoff (crusted or loosened) present primary parameters of every experiment. On the basis of different combinations of setting, 2 representative evaluation states of the minimum (min LC) and maximum (max LC) load conditions were established. The most important data obtained at the Simulator are soil moisture content, progression of surface runoff, soil loss and infiltration. Results clearly show dependence of initial moisture content on physical properties, when impervious soils with high fraction of clay reach over 30 % wt., pervious soils with high fraction of sand achieve initial average moisture content only about 20 % wt. Results of steady-state values of surface runoff and soil loss for minimum and maximum load conditions and its ratio show that highest increase of values due to higher load conditions reach silt loamy soil (Horomerice), silt clay loamy soil (Klapy) and loamy soil (Vsetaty), while the lowest increase reach silt loamy soil (Trebsin I) and sandy loamy soil (Trebesice I). General trend in all cases is obviously to increase both values, but while the average values of surface runoff increased 2.1-times, in the case of soil loss steady state values increased even 5.6-times. During these 12 years of experimental research, large sets of data were collected and used for comparison of behaviour of different soils under extreme conditions and also as input parameters for recalibration of SMODERP (Simulation Model for Determination of Surface Runoff and Erosion Processes) which has been developed at the same departement since 1989. This research is supported by grant: SGS14/180/OHK1/3T/11 Rainfall-runoff, erosion and transport processes - experimental research.

  6. Numerical and experimental investigation of cloud droplet collision-coalescence

    Science.gov (United States)

    Rosa, B.; Aliseda, A.; Bateson, C.; Ayala, O.; Parishani, H.; Wang, L. P.

    2012-04-01

    In recent years there has been significant progress in the field of numerical weather prediction (NWP). New and more efficient algorithms together with modern supercomputers offer hitherto unattainable possibilities of modeling severe weather phenomena with greater accuracy. Spatial resolution of the contemporary NWP models is of the order of 1km and is being further reduced. Such a resolution approaches the regime for which the convective processes can be explicitly represented. Nevertheless, moist processes related to cloud physics still need to be better parameterized. Investigation of the moist processes by direct measurements of droplet-droplet and droplet-turbulence interactions in real clouds is difficult due to the short time and length scales involved. In this study we focus on the numerical and laboratory-experimental investigation of collision-coalescence of cloud droplets. Quantitative description of this process is of great importance since the collision-coalescence plays important role in the development of warm rain, that is, transformation of small cloud droplets to rain drops. Our experimental approach is aimed at developing in the wind tunnel a turbulent flow and droplet distribution similar to those occurring in the real cloud. Using direct numerical simulations (DNS) we are able to realistically reproduce the conditions that take place in the wind tunnel. Together, we hope to combine these two different tools to gain a better quantitative understanding of turbulent collision-coalescence of cloud droplets. In the simulations we modeled motion of small inertial droplets (Stokes number in the range of 0.1 to 10) immersed in homogeneous slowly decaying isotropic turbulent flow. Droplet statistics have been analyzed for different initial spectra of the turbulent flow. The Reynolds number was limited by the laboratory and DNS accessibility to around 400. The key result is the comparison of the one-dimensional (1D) Radial Distribution Function (RDF) from the experiments with the 1D and 3D RDFs from the simulations. The comparison allows us to validate the numerical treatment of the droplet dynamics in close proximity, and to develop methods to extrapolate the experimental measurements to 3D. We will also compare the relative velocity of droplet pairs, obtained along a line or plane from PDPA and PIV measurements, to the equivalent statistics obtained from the 3D velocity fields in the DNS.

  7. Experimental and theoretical investigation of electrokinetic decontamination of concrete

    International Nuclear Information System (INIS)

    Contamination of concrete by radionuclides and metals is a widespread problem throughout the nuclear power industry and the Department of Energy. Electrokinetic decontamination appears to be an attractive technology for application to this problem due to the possibility for decontamination without removal of concrete and limited labor requirements; however, further experimental and theoretical work is necessary to fully understand the process and to define the capabilities and limitations of the technology. This paper presents details of experimental and theoretical studies of the process and their implications for field demonstrations. Preliminary results of these studies indicate that electroosmosis is not likely to be the dominant transport mechanism in most cases; rather, most species will be transported by electromigration. Batch equilibration tests have shown that removal of each contaminant will be governed largely by the chemistry of the concrete, contaminant, and lixiviant; in particular, precipitation of species such as cobalt and uranium will limit transport in the normally high-pH concrete pore solution. It is recommended that laboratory determination of site-specific isotherms be made prior to demonstrations of this technology. Dynamic experiments indicate that it is possible to transport non-precipitating species. The results of a computational model have been shown to be in good agreement with dynamic experiments; therefore, this model will provide a valuable tool for the further investigation and optimization of electrokinetic decontamination of concrete

  8. Computational and experimental investigation of magnetized target fusion

    International Nuclear Information System (INIS)

    In Magnetized Target Fusion (MTF), a preheated and magnetized target plasma is hydrodynamically compressed to fusion conditions. Because the magnetic field suppresses losses by electron thermal conduction in the fuel during the target implosion heating process, the compression may be over a much longer time scale than in traditional inertial confinement fusion (ICF). Bigger targets and much lower initial target densities than in ICF can be used, reducing radiative energy losses. Therefore, ''liner-on-plasma'' compressions, driven by relatively inexpensive electrical pulsed power, may be practical. Potential MTF target plasmas must meet minimum temperature, density, and magnetic field starting conditions, and must remain relatively free of high-Z radiation-cooling-enhancing contaminants. At Los Alamos National Laboratory, computational and experimental research is being pursued into MTF target plasmas, such as deuterium-fiber-initiated Z-pinches, and the Russian-originated MAGO plasma. In addition, liner-on-plasma compressions of such target plasmas to fusion conditions are being computationally modeled, and experimental investigation of such heavy liner implosions has begun. The status of the research will be presented

  9. Experimental and Theoretical Investigations of Wet Flue Gas Desulphurisation

    DEFF Research Database (Denmark)

    Kiil, SØren

    1998-01-01

    This thesis describes experimental and theoretical investigations of wet flue gas desulphurisa-tion (FGD). A review of the current knowledge of the various rate determining steps in wet FGD plants is presented. The experimental work covers laboratory studies as well as pilot- and full-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 limestones of dif-ferent origin were tested. A transient, mass transport controlled, mathematical model was de-veloped to describe the dissolution process. Model predictions were found to be qualitatively in good agreement with experimental data. Deviations between measurements and simulations were attributed primarily to the particle size distribution (PSD) measurements of the limestone particles, which were used as model inputs. The measured PSD was probably not representa-tive of a given limestone sample because of agglomeration phenomena taking place in the dis-perser, preventing a stable and accurate measurement. Other factors, such as convective mass transfer, porosity and porosity changes, and perhaps surface reaction, may also influence the rate of dissolution. However, those effects could not, due to the uncertainty of the PSD, be confirmed. Empirical correlations for the dimensionless mass transfer coefficients in a pilot plant (falling- film column) were determined. The correlations are valid at gas phase Reynolds numbers from 7500 to 18,300 and liquid phase Reynolds numbers from 4000 to 12,000, conditions of industrial relevance. The presence of inert particles in the liquid phase was found to decrease the rate of gas phase mass transport with up to 15 %, though the effect could not be correlated.A detailed model for a wet FGD pilot plant, based on the falling film principle, was devel-oped. All important rate determining steps, absorption of SO2, oxidation of HSO3-, dissolution of limestone, and crystallisation of gypsum were included. Model predictions were compared to experimental data such as gas phase concentration profiles of SO2, slurry pH-profiles, sol-ids contents of the slurry, liquid phase concentrations, and residual limestone in the gypsum. Simulations were found to match experimental data for the two Danish limestone types (Faxe Bryozo and a chalk, Mikrovit) investigated. Gas phase mass transport was found to be the dominating rate determining step, though the liquid phase mass transport resistance could not be neglected. Simulations and experimental data both showed the same degree of desulphuri-sation and absorber pH profile for the two limestone types using a holding tank pH of 5.5, but the residual limestone in the gypsum was significantly lower for the chalk. Furthermore, simulations showed that between 10 and 30 % of the limestone dissolves in the absorber de-pending on the process conditions. A typical holding tank pH of 5-5.5 (also used in full-scale wet FGD packed towers) was found to be a reasonable compromise between residual lime-stone in the gypsum and the degree of desulphurisation. Simulations were only slightly sensi-tive to the 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 ash from the full-scale experiments showed a decrease in limestone reactivity. However, the test period was only about one week, probably not allowing the FGD plant to reach steady state operation. Pilot-scale experiments were initiated to investigate the possibility of oxidising spray dry scrubber by-products (TASP) to gypsum in wet FGD plants. The investigations showed that it was possible to oxidise the TASP at concentrations of up to 300 g/litre (feed tank basis

  10. Experimental and numerical investigations on melamine wedges.

    Science.gov (United States)

    Schneider, S

    2008-09-01

    Melamine wedges are often used as acoustic lining material for anechoic chambers. It was proposed here to study the effects of the mounting conditions on the acoustic properties of the melamine wedges used in the large anechoic chamber at the LMA. The results of the impedance tube measurements carried out show that the mounting conditions must be taken into account when assessing the quality of an acoustic lining. As it can be difficult to simulate these mounting conditions in impedance tube experiments, a numerical method was developed, which can be used to complete the experiments or for parametric studies. By combining the finite and the boundary element method, it is possible to investigate acoustic linings with almost no restrictions as to the geometry, material behavior, or mounting conditions. The numerical method presented here was used to study the acoustic properties of the acoustic lining installed in the anechoic chamber at the LMA. Further experiments showed that the behavior of the melamine foam is anisotropic. Numerical simulations showed that this anisotropy can be used to advantage when designing an acoustic lining. PMID:19045648

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Geoengineering characterization of welded tuffs from laboratory and field investigations

    International Nuclear Information System (INIS)

    Welded tuff beneath Yucca Mountain adjacent to the Nevada Test Site (NTS) is being considered for development as a high-level radioactive waste repository by the Nevada Nuclear Waste Storage Investigations (NNWSI) Project. Because access into Yucca Mountain has been limited to borehole explorations, early geoengineering materials characterizations have been derived from laboratory tests on cores from Yucca Mountain and from laboratory and field tests on welded tuffs located in G-Tunnel on the NTS. G-Tunnel contains welded tuffs that have similar properties and stress states to those at Yucca Mountain and has been the location for in situ rock mechanics testing. The purpose of this paper is to summarize the geoengineering material property data obtained to date and to compare appropriate laboratory and field data from G-Tunnel to findings from Yucca Mountain. Geomechanical and thermal data are provided and are augmented by limited geological and hydrological data. A comparison of results of laboratory measurements on tuffs from Yucca Mountain and G-Tunnel indicates good agreement between the bulk densities, saturations, moduli of elasticity, Poisson's ratios, and P-wave velocities. The G-Tunnel tuff has slightly lower thermal conductivity, tensile strength, compressive strength and slightly higher matrix permeability than does the welded tuff near the proposed repository horizon at Yucca Mountain. From a laboratory-to-field scaling perspective, the modulus of deformation shows the most sensitivity to field conditions because of the presence of the joints found in the field. 14 references, 1 table

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

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas BØdker

    The role of ions in producing aerosols in Earth’s atmosphere is an area of very active research. Atmospheric (Clarke et al. 1998) and experimental (Berndt et al. 2005) observations have shown that the nucleation of aerosol particles can occur under conditions that cannot be explained by classical 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 removed from those relevant for the lower part of the atmosphere (Bricard et al. 1968). Recent experimental work (Svensmark et al. 2007) demonstrated that ions, produced by cosmic rays in the atmosphere, are likely to play an important role in the production of new aerosol particles. The mechanism whereby energetic cosmic rays can promote the production of cloud condensation nuclei at low altitudes constitutes a linkbetween 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 setup The experiments were conducted in a 50 L cylindrical reaction chamber made of electropolished stainless steel. Aerosols were grown using photochemically produced sulphuric acid and ionization levels were controlled with a Cs-137 gamma-source. An increase in nucleation was observed when the chamber was exposed to the radioactive source. The results were analyzed using a model based on the General Dynamic Equation and the analysis revealed that Ion Induced Nucleation is the most likely mechanism for the observed nucleation increases and thus confirm the previous results.

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

    Energy Technology Data Exchange (ETDEWEB)

    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 modern turbine engines; and What advancements in film cooling hole geometry and design can increase effectiveness of film cooling in turbines burning high-hydrogen coal syngas due to the higher heat loads and mass flow rates of the core flow? Experimental and numerical investigations of advanced cooling geometries that can improve resistance to surface deposition were performed. The answers to these questions were investigated through experimental measurements of turbine blade surface temperature and coolant coverage (via infrared camera images and thermocouples) and time-varying surface roughness in the NETL high-pressure combustion rig with accelerated, simulated surface deposition and advanced cooling hole concepts, coupled with detailed materials analysis and characterization using conventional methods of Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), 3-D Surface Topography (using a 3-D stylus profilometer). Detailed surface temperatures and cooling effectiveness could not be measured due to issues with the NETL infrared camera system. In collaboration with faculty startup funding from the principal investigator, experimental and numerical investigations were performed of an advanced film cooling hole geometry, the anti-vortex hole (AVH), focusing on improving cooling effectiveness and decreasing the counter-rotating vortex of conventional cooling holes which can entrain mainstream particulate matter to the surface. The potential benefit of this program is in gaining a fundamental understanding of how the use of alternative fuels will effect the operation of modern gas turbine engines, providing valuable data for more effective cooling designs for future turbine systems utilizing alternative fuels.

  15. Laboratory investigation of platelet function: a review of methodology.

    OpenAIRE

    Yardumian, D A; Mackie, I.J.; Machin, S.J.

    1986-01-01

    Over the past decade interest in and knowledge about the role of platelets in the haemostatic process and in various pathological conditions has continued to grow. The scope of laboratory methodology to investigate platelet function in clinical haemorrhagic and thrombotic disorders in the specialised haemostasis unit has also proportionally widened. After highlighting the physiological processes of the role of platelets in the haemostatic mechanism this brief review comments critically on the...

  16. Experimental Investigation of Ventilation of a Surface Piercing Hydrofoil

    Science.gov (United States)

    Harwood, Casey; Miguel Montero, Francisco; Young, Yin Lu; Ceccio, Steven

    2013-11-01

    Bodies that pierce a liquid free-surface are prone to entrainment of atmospheric and/or vaporous gases. This process, called ventilation, can occur suddenly and violently, drastically altering hydrodynamic response. Experiments have been conducted at the free-surface towing-tank in the University of Michigan Marine Hydrodynamics Laboratory to investigate fully attached, partially ventilated, and fully ventilated flows around a canonical surface-piercing hydrofoil. The objectives of the work are: (i) to gain a broad and improved understanding of the physics of ventilation, (ii) to classify the physical mechanisms by which ventilation inception and washout may occur and quantify the conditions required for each mechanism and (iii) to quantify the effects of ventilation on global hydrodynamic responses, including the six force and moment components. Experimental data and high-speed video will be used to illustrate the impact of ventilation on hydrodynamic loads, pressures, and flow structures. The completion of this study is expected to contribute significantly toward a comprehensive understanding of ventilation physics, and toward an improved ability to design safe and controllable ventilated lifting surfaces for use in propulsion, energy harvesting, and turbomachinery. Bodies that pierce a liquid free-surface are prone to entrainment of atmospheric and/or vaporous gases. This process, called ventilation, can occur suddenly and violently, drastically altering hydrodynamic response. Experiments have been conducted at the free-surface towing-tank in the University of Michigan Marine Hydrodynamics Laboratory to investigate fully attached, partially ventilated, and fully ventilated flows around a canonical surface-piercing hydrofoil. The objectives of the work are: (i) to gain a broad and improved understanding of the physics of ventilation, (ii) to classify the physical mechanisms by which ventilation inception and washout may occur and quantify the conditions required for each mechanism and (iii) to quantify the effects of ventilation on global hydrodynamic responses, including the six force and moment components. Experimental data and high-speed video will be used to illustrate the impact of ventilation on hydrodynamic loads, pressures, and flow structures. The completion of this study is expected to contribute significantly toward a comprehensive understanding of ventilation physics, and toward an improved ability to design safe and controllable ventilated lifting surfaces for use in propulsion, energy harvesting, and turbomachinery. Supported by: The Office of Naval Research (ONR) (Grant No. N00014-09-1-1204); the National Research Foundation of Korea (NRF) (GCRC-SOP Grant No. 2012-0004783); the National Science Foundation Graduate Student Research Fellowship (Grant No. DGE 1256260).

  17. Experimental Investigation of the Trigger Problem in Magnetic Reconnection

    Science.gov (United States)

    Egedal, Jan

    2012-07-01

    Magnetic reconnection releases magnetic energy not only in steady-state, but also in time-dependent and often explosive events requiring a transition from slow reconnection to fast. The question of what causes this transition is known as the ``trigger problem'' and is not well understood. We address the trigger problem using the Versatile Toroidal Facility (VTF) at MIT. We observe spontaneous reconnection events [1] with exponentially growing reconnection rates, and we characterize the 3D dynamics of these events using multiple internal probes. The observed reconnection is asymmetric: it begins at one toroidal location and propagates around in both directions. The spontaneous onset is facilitated by an interaction between the x-line current channel and a global mode in the electrostatic potential. It is this mode which breaks axisymmetry and enables a localized decrease in x-line current. We model the onset using an empirical Ohm's law and current continuity, which is maintained by ion polarization currents associated with the mode. The model reproduces the exponential growth of the reconnection electric field, and the model growth rate agrees well with the experimentally measured growth rate. The onset location is likely determined by small asymmetries in the in-vessel coils. To further investigate this conjecture new coils have been installed, which allow for controlled changes in toroidal asymmetry. The observations are suggestive of solar flare dynamics and are relevant to tokamak research [3]. [1] Egedal, J. et al. Laboratory Observations of Spontaneous Magnetic Reconnection. Phys. Rev. Lett. 98, 015003 (2007). [2] Katz, N. et al. Laboratory Observation of Localized Onset of Magnetic Reconnection. Phys. Rev. Lett. 104, 255004 (2010). [3] Park, H.K. et al. Self-organized Te redistribution during driven reconnection processes in high-temperature plasmas. Phys. Plasmas 13, 055907 (2006).

  18. Experimental study of driven magnetic relaxation in a laboratory plasma

    Science.gov (United States)

    Hsu, S. C.; Tang, X. Z.

    2008-11-01

    The Driven Relaxation Experiment (DRX) has been built at LANL to investigate the possibility of exploiting resonances in the nonlinear force-free equation [1] to optimize magnetic flux amplification and current multiplication for driven-relaxed spheromak-like plasmas, and to explore the application of these ideas to plasma astrophysics problems [2]. It is also our goal to see whether relaxed states with ?> ?1 can be formed and sustained. The experiment uses a planar magnetized coaxial gun (100--180 kA, 1--7 mWb) to generate driven- relaxed plasmas within a cylindrical flux-conserving boundary (0.9 m diameter). Unique features of DRX include high ?gun up to 3?1, and a continuously adjustable boundary elongation. The gun is powered by a 3- stage capacitor bank to form (10 kV, 500 ?F) and sustain (5 kV, 8 mF) the plasma for up to 500 ?s, corresponding to >10 Sweet-Parker times which allows the plasma to reach a quasi-steady-state. The primary diagnostic is a 48- channel 2D magnetic probe array that will map out a poloidal cross-section of the magnetic field configuration at one toroidal position. The full equilibrium magnetic field will be constructed using a combination of the experimental data and a nonlinear force-free equilibrium solver. We will present details of the experimental setup and the first experimental data. Supported by LANL LDRD. [1] Tang & Boozer, PRL 94, 225004 (2005); PRL 98, 175001 (2007) [2] Tang, ApJ 679, 1000 (2008).

  19. Reduction of friction in fluid transport: experimental investigation

    Scientific Electronic Library Online (English)

    G., Aguilar; K., Gasljevic; E.F., Matthys.

    2006-10-01

    Full Text Available La reducción de fricción o de arrastre (DR) mediante el uso de soluciones poliméricas o surfactantes es sin duda alguna la técnica de reducción de fricción para flujos turbulentos en tuberías mas efectiva (es posible obtener reducciones de hasta un factor de 8 en los coeficientes de fricción en segm [...] entos de tuberías rectas). Desde el punto de vista fundamental, el estudio del fenómeno de DR ofrece la oportunidad de comprender mejor flujos turbulentos; desde el punto de vista práctico, la DR puede ser usada con propositos de ahorro en potencia de bombeo. La implementación comercial de estos aditivos se ha llevado a cabo con éxito en el transporte de petróleo, y la investigación necesaria para la implementación de estas soluciones en muchas otras aplicaciones sigue en proceso, p.ej., en sistemas centrales de calefacción y aire acondicionado, sistemas hidrónicos en edificios, desagües, irrigación, procesos industriales, etc. Nuestros esfuerzos se han enfocado en dos áreas principales: (A) investigación experimental sobre la transferencia de momentum y calor para soluciones reductoras de fricción, y (B) la implementación de estas soluciones en sistemas hidrónicos de enfriamiento en edificios con el propósito de ahorrar energía. Este documento pretende dar una noción general de la investigación experimental que llevamos a cabo en nuestro laboratorio de dinámica de fluidos no-Newtonianos, reología, y transferencia de calor en la UCSB. Abstract in english Drag reduction (DR) by the use of polymer and surfactant solutions is by far the most effective drag-reducing technique for turbulent flows (up to 8-fold reduction in friction coefficients is possible on straight pipes). From a fundamental point of view, the study of the DR phenomenon offers an oppo [...] rtunity for a better understanding of turbulence in general; from a practical point of view, DR can be used to save pumping power. Commercial implementation of drag-reducing fluids has proved successful for oil pipeline transportation, and looks promising for many other applications that are still under investigation, e.g. district heating or cooling systems, hydronic systems in buildings, sewers, irrigation, industrial processes, etc. Our efforts have focused on two main areas: (A) experimental research on momentum and heat transfer of turbulent flows of drag-reducing solutions, and (B) implementation of these solutions in hydronic cooling systems in buildings for energy conservation purposes. This paper describes an overview of the typical experimental research that we conduct in our non-Newtonian fluid mechanics, rheology, and heat transfer laboratory at UCSB.

  20. Seismic and geologic investigations of the Sandia Livermore Laboratory site

    International Nuclear Information System (INIS)

    This report describes results of a seismic and geologic investigation in the vicinity of Sandia Laboratories property and Sandia's Tritium Building at Livermore, California. The investigation was done to define any seismically capable faults in the immediate area and to obtain necessary information to support estimates of future possible or probable ground motions. The work included a variety of geophysical measurements, trenching, seismologic studies, geologic examination, and evaluation of possible ground surface rupture at the site. Ground motions due to the maximum potential earthquake are estimated, and probability of exceedance for various levels of peak ground acceleration is calculated. Descriptions of the various calculations and investigative techniques used and the data obtained are presented. Information obtained from other sources relevant to subsurface geology and faulting is also given. Correlation and evaluation of the various lines of evidence and conclusions regarding the seismic hazard to the Tritium Building are included

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

    International Nuclear Information System (INIS)

    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 the most preferable characteristics. ? Frozen biomass was statistically similar to freshly ensiled stover. ? Modified phenol-sulfuric method provides appropriate results and better resolution.

  2. A global remote laboratory experimentation network and the experiment service provider business model and plans

    OpenAIRE

    Tor Ivar Eikaas; Christian Schmid; Foss, Bjarne A.; Denis Gillet

    2003-01-01

    This paper presents results from the IST KAII Trial project ReLAX - Remote LAboratory eXperimentation trial (IST 1999-20827), and contributes with a framework for a global remote laboratory experimentation network supported by a new business model. The paper presents this new Experiment Service Provider business model that aims at bringing physical experimentation back into the learning arena, where remotely operable laboratory experiments used in advanced education and training schemes are m...

  3. Laboratory investigation of the loading rate effects in sand:

    OpenAIRE

    Huy, N.Q.; Van Tol, A.F.; Hölscher, P.

    2006-01-01

    In order to improve the interpretation of the quasi-static (e.g. Statnamic) pile load tests, a research project has been started to investigate effects of the loading rate on the bearing capacity of a pile in sand. A series of laboratory tests has been carried out. The testing program consists of a series of triaxial tests for sand and a series of load tests on a model pile embedded in sand in a large calibration chamber. The research pointed at answering two fundamental questions: - Th...

  4. Numerical and experimental investigation of a gully under surcharge conditions

    OpenAIRE

    Lopes, Pedro; Leandro, Jorge; Carvalho, Rita Fernandes; Páscoa, Patrícia; Martins, Ricardo

    2015-01-01

    This paper deals with numerical and experimental investigation of a gully under exceptional situations after the sewer system becomes pressurized. These results are useful for the calibration and validation of the linking elements found in Dual Drainage (DD) models. The experimental results were obtained in the MLE (Multiple-Linking-Element) experimental installation that allows the simulation of full surcharge flow through a gully. The installation consists of an 8 m long and 0.5 m wide chan...

  5. Sprite discharges on Venus and Jupiter-like planets: a laboratory investigation

    OpenAIRE

    Dubrovin, S.; Nijdam, S; Van Veldhuizen, E.M.; Ebert, U.; Yair, Y.; Price, C

    2010-01-01

    Large sprite discharges at high atmospheric altitudes have been found to be physically similar to small streamer discharges in air at sea level density. Based on this understanding, we investigate possible sprite discharges on Venus or Jupiter-like planets through laboratory experiments on streamers in appropriate CO2-N2 and H2-He mixtures. First, the scaling laws are experimentally confirmed by varying the density of the planetary gasses. Then streamer diameters, velocities and overall morph...

  6. Laboratory and numerical investigations of air sparging using MTBE as a tracer

    DEFF Research Database (Denmark)

    Mortensen, A. P.; Jensen, Karsten Høgh; Sonnenborg, T. O.; Arvin, E.

    2000-01-01

    Air sparging experiments were conducted in a laboratory column to investigate air now and mass transfer behavior in different types of sand at different air injection rates. Methyl tertiary butyl ether (MTBE) was applied as a tracer, and by measuring the volatilization and the mean air content during the experiments, the air flow pattern and its influence on mass transfer were assessed. The experimental results showed large differences among the sand types. In fine sand, the mean air content was...

  7. Sprite discharges on Venus and Jupiter-like planets: a laboratory investigation

    OpenAIRE

    Dubrovin, D; Nijdam, S; Veldhuizen, EM (Eddie) van; Ebert, UM (Ute); Yair, Y.; Price, C

    2010-01-01

    Large sprite discharges at high atmospheric altitudes have been found to be physically similar to small streamer discharges in air at sea level density. Based on this understanding, we investigate possible sprite discharges on Venus or Jupiter-like planets through laboratory experiments on streamers in appropriate CO2-N2 and H2-He mixtures. First, the scaling laws are experimentally confirmed by varying the density of the planetary gasses. Then streamer diameters, velocities...

  8. An experimental investigation of untriggered film boiling collapse

    International Nuclear Information System (INIS)

    Film boiling has been investigated in a stagnant pool, using polished brass or anodised aluminium alloy rods in water. Experimental boiling curves were obtained, and pronounced ripples on the vapour/liquid interface were photographed. A criterion for untriggered film boiling collapse is proposed, consistent with experimental results. Application of the results to molten fuel coolant interaction studies is discussed. (U.K.)

  9. Experimental and analytical investigation of Paks NPP building structures

    International Nuclear Information System (INIS)

    The dynamic characteristics of WWER-440 NPP building structures were experimentally investigated using explosive techniques. The same characteristics were calculated analytically. The comparison of experimental and analytical results show the adequacy of the modeling of the structures and soil-structure interaction. (author)

  10. Attachment theory and paranoid cognitions: An experimental investigation

    OpenAIRE

    Owens, Jane

    2013-01-01

    This thesis has been prepared in paper based format. The thesis focusses of the use of experimental manipulations in the investigation of paranoia and extends the use of these to an empirical investigation of the role of attachment theory in paranoia. Papers 1 and 2 have been prepared for submission to Clinical Psychology Review and Schizophrenia Bulletin respectively. Paper 1 provides a comprehensive overview of experimental paradigms that aim to induce or manipulate paranoid thinking in ...

  11. Experimental Investigation in Fluid Mechanics – Its Role, Problems and Tasks

    OpenAIRE

    Šafa?ík P.

    2013-01-01

    In this contribution, some problems and tasks of experimental fluid mechanics are presented. Paradoxes, basic laws and contemporary investigation approaches are discussed. Experimental results, together with theoretical knowledge and numerical simulations gradually form basis for solution of topical problems. The author of this contribution focuses his investigations into field of compressible fluid flow. Due to this, some results of high-speed aerodynamic research contributing to design and ...

  12. Laboratory Investigations on Estuary Salinity Mixing: Preliminary Analysis

    Directory of Open Access Journals (Sweden)

    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.

  13. Experimental Investigation and Modeling of Integrated Tri-generation Systems

    Science.gov (United States)

    Cetinkaya, Eda

    Energy demand in the world is increasing with population growth and higher living standards. Today, the need for energy requires a focus on renewable sources without abandoning fossil fuels. Efficient use of energy is one of the most important tasks in modern energy systems to achieve. In addition to the energy need, growing environmental concerns are linked with energy is emerged. Multi-purpose energy generation allows a higher efficiency by generating more outputs with the same input in the same system. Tri-generation systems are expected to provide at least three commodities, such as heating, cooling, desalination, storable fuel production and some other useful outputs, in addition to power generation. In this study, an experimental investigation of gasification is presented and two integrated tri-generation systems are proposed. The first integrated tri-generation system (System 1) utilizes solar energy as input and the outputs are power, fresh water and hot water. It consists of four sub-systems, namely solar power tower system, desalination system, Rankine cycle and organic Rankine cycle (ORC). The second integrated tri-generation system (System 2) utilizes coal and biomass as input and the outputs are power, fuel and hot water. It consists of five sub-systems: gasification plant, Brayton cycle, Rankine cycle, Fischer-Tropsch synthesis plant and an organic Rankine cycle (ORC). Experimental investigation includes coal and biomass gasification, where the experimental results of synthesis gas compositions are utilized in the analysis of the second systems. To maximize efficiency, heat losses from the system should be minimized through a recovery system to make the heat a useful commodity for other systems, such as ORCs which can utilize the low-grade heat. In this respect, ORCs are first analyzed for three different configurations in terms of energy and exergy efficiencies altering working fluids to increase the power output. Among two types of coal and one type biomass tried in the laboratory scale experimental set-up, Tuncbilek-Omerler is found to be superior to Konya-Ilgin coal in terms of the highest amount of hydrogen in the synthesis gas composition. As biomass, wheat straw is gasified, which shows higher exergetic efficiency in comparison to Konya-Ilgin coal. Based on theoretical analysis conducted for the integrated systems, System 2 is found to be more efficient in terms of energy and exergy in comparison with System 1. However, when local needs are taken into account, fresh water can be a desirable useful output where solar irradiation is high. Both systems are compared to conventional and co-generation systems having the same inputs to quantify the improvement in efficiency. System 1 has an energy efficiency of 69% and an exergy efficiency of 58%, whereas System 2 has an energy efficiency of 71% and an exergy efficiency of 73%. When single generation is obtained from the same inputs, it is observed that the energy and exergy efficiencies drop drastically down to 34% and 42% for System 1; 33% and 42% for System 2, respectively.

  14. EXPERIMENTAL INVESTIGATION OF CRITICAL FUNDAMENTAL ISSUES IN HAZARDOUS WASTE INCINERATION

    Science.gov (United States)

    The report gives results of a laboratory-scale program investigating several fundamental issues involved in hazardous waste incineration. The key experiment for each study was the measurement of waste destruction behavior in a sub-scale turbulent spray flame. (1) Atomization Qual...

  15. Experimental Investigations on a Novel Chemical Looping Combustion Configuration

    International Nuclear Information System (INIS)

    Chemical Looping Combustion (CLC) is a promising novel combustion technology involving inherent separation of carbon dioxide with minimum energy penalty. An oxygen carrier is employed to continuously transfer oxygen from the air reactor to the fuel reactor where the oxygen is delivered to the fuel. Consequently, direct contact between the air and fuel is prevented. The resulting flue gas is CO2-rich, without N2 dilution. The reduced oxygen carrier is then transported back to the air reactor for re-oxidation purposes, hence forming a chemical loop. Various CLC configurations have already been developed and tested on laboratory scales. However, more investigations are required to achieve feasible CLC processes. Among the different points to address, control of the solid circulation rate between the two reactors is of the highest importance regarding its effect on achievement of an appropriate oxygen transfer rate and solid oxidation degrees. Moreover, minimization of gas leakage between the fuel and air reactors is another important issue to be considered. A novel CLC configuration is proposed where reactions are carried out in two interconnected bubbling fluidized beds. Solid circulation rate control is achieved independently of gas flow rate in the reactors through use of pneumatic non-mechanical valves (L-valves). Moreover, loop-seals are employed to minimize gas leakage while transferring solids. Experimental results from operation of a 10 kWth equivalent cold prototype are presented in this paper. The effect of operating variables on the solid circulation rate, gas leakage between the two beds and the pressure balance on all of the process elements is studied. The results demonstrate stable solid circulation with efficient control of the solid flow rate and effective gas tightness of the system. (authors)

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

    Science.gov (United States)

    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

  17. Experimental and Analytical Investigations of Piles and Abutments of Integral Bridges

    OpenAIRE

    Sami Arsoy; Barker, Richard M; J. Michael Duncan

    2002-01-01

    This research investigated, through experimental and analytical studies, the complex interactions that take place between the structural components of an integral bridge and the adjoining soil. The ability of piles and abutments to withstand thermally induced cyclic loads was investigated by conducting large-scale cyclic load tests. Three pile types and three integral abutments with hinges were tested in the laboratory. Experiments simulated 75 years of bridge life. Numerical analyses were co...

  18. Experimental investigation of mixtures of bentonite and dredged sediments from Chorfa dam in Algeria

    OpenAIRE

    LABIOD-ALOUI, Zehour; TROUZINE, Habib; GHEMBAZA, Moulay Smaïne; NOUIOUA, Tahar; SEBAIBI, Yahya

    2014-01-01

    Geotechnical properties of dredged sediment from Chorfa dam in Algeria and their mixtures (5%, 10%, 15%, 20%, and 25%) with bentonite were investigated through a series of laboratory experimental tests in order to investigate possibilities of their usage as a barrier against the spread out of the Sebkha of Oran in the northwest of Algeria. Grain size and Atterberg limits tests, chemical and mineral analyses, and compaction, vertical swelling, and horizontal and vertical permeability tests wer...

  19. Historical Jeroným Mine in ?istá – Underground Experimental Geotechnical Laboratory.

    Czech Academy of Sciences Publication Activity Database

    Kaláb, Zden?k; Hrubešová, E.; Ko?ínek, R.; Ž?rek, P.; Kukutsch, Radovan

    2012-01-01

    Ro?. 21, ?. 1 (2012), s. 54-65. ISSN 1211-0728 R&D Projects: GA ?R GA105/09/0089 Institutional research plan: CEZ:AV0Z3086906 Keywords : Jeroným Mine * geotechnical laboratory * monitoring Subject RIV: DC - Siesmology, Volcanology, Earth Structure http://www.ita-aites.cz/files/tunel/komplet/tunel_1_12.pdf

  20. Experimental econophysics properties and mechanisms of laboratory markets

    CERN Document Server

    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...

  1. Russian fast research reactor BOR-60 reactor: Experimental investigations

    International Nuclear Information System (INIS)

    Experimental fast reactor BOR-60 is one of the leading experimental facilities in Russia used to test a large of number fuel pins, fuel assemblies, and control rods of different designs, fuel compositions and structural materials. It is also widely used for trying out the elements of closed fuel cycle, transmutation of actinides and plutonium utilization. BOR-60 reactor and high-capacity experimental base available at RIAR allow various experimental investigations to be performed. Since the BOR-60 startup (in 1969), a large scope of experiments have been done at RIAR practically in all directions that are of interest for the nuclear power engineering and related areas of science and engineering. In addition, a wide experience has been gained in calculation support of experimental investigations. During its 40-year operation, the BOR-60 core underwent multiple changes. There were more than 120 micro-runs, each micro-run being a reactor state different from others. The experimental investigations performed in different periods of time may be of interest for a researcher. Results obtained at this reactor contributed greatly to the development of the nuclear power engineering and made a basis for a successful startup and operation of reactors BN-350 and BN-600 as well as for long and safe operation of BOR-60 itself. At present, both the reactor and experiment gained at it are widely used for justification of promising fast reactors

  2. Experimental method for investigating helium effects in irradiated vanadium

    International Nuclear Information System (INIS)

    Analyses have been performed which indicate that an effective method for experimentally investigating helium effects in neutron irradiated vanadium base alloys can be developed. The experimental procedure involves only modest modifications to existing procedures currently used for irradiation testing of vanadium-base alloys in the FFTF reactor. Helium is generated in the vanadium alloy by decay of tritium which is either preinjected or generated within the test capsule. Calculations indicate that nearly constant He/dpa ratios of desired magnitude can be attained by proper selection of experimental parameters. The proposed method could have a major impact on the development of vanadium base alloys for fusion reactor applications. 8 refs., 4 figs

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Experimental investigations of overvoltages in neutral isolated networks

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Science.gov (United States)

    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…

  6. Investigating Systematic Uncertainty and Experimental Design with Projectile Launchers

    CERN Document Server

    Orzel, Chad; Marr, Jonathan

    2011-01-01

    The proper choice of a measurement technique that minimizes systematic and random uncertainty is an essential part of experimental physics. These issues are difficult to teach in the introductory laboratory, though: because most experiments involve only a single measurement technique, students are often unable to make a clear distinction between random and systematic uncertainties, or to compare the uncertainties associated with different techniques. In this paper, we describe an experiment suitable for an introductory college level (or advanced high school) course that uses velocity measurements to clearly show students the effects of both random and systematic uncertainties.

  7. PLACE: an open-source python package for laboratory automation, control, and experimentation.

    Science.gov (United States)

    Johnson, Jami L; Tom Wörden, Henrik; van Wijk, Kasper

    2015-02-01

    In modern laboratories, software can drive the full experimental process from data acquisition to storage, processing, and analysis. The automation of laboratory data acquisition is an important consideration for every laboratory. When implementing a laboratory automation scheme, important parameters include its reliability, time to implement, adaptability, and compatibility with software used at other stages of experimentation. In this article, we present an open-source, flexible, and extensible Python package for Laboratory Automation, Control, and Experimentation (PLACE). The package uses modular organization and clear design principles; therefore, it can be easily customized or expanded to meet the needs of diverse laboratories. We discuss the organization of PLACE, data-handling considerations, and then present an example using PLACE for laser-ultrasound experiments. Finally, we demonstrate the seamless transition to post-processing and analysis with Python through the development of an analysis module for data produced by PLACE automation. PMID:25304874

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

    OpenAIRE

    Hall, Adam C.; Mary E. Harrington

    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...

  9. Oak Ridge National Laboratory Research Reactor Experimenters' Guide

    International Nuclear Information System (INIS)

    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

  10. Laboratory studies of pre-solar grains: experimental astrophysics

    Science.gov (United States)

    Hsu, W. B.

    2006-01-01

    Primitive meteorites contain microscopic pre-solar grains that originated from stellar outflows and supernova ejecta. Identified phases include nano-diamond, graphite, silicon carbide, corundum, spinel, hibonite, and silicates. Their stellar origin was manifested by enormous isotopic compositions compared to solar materials. They are the solid samples from various stellar sources, including red giant stars, AGB stars, novae, and supernovae. Laboratory isotopic analyses of these grains provide a deeper understanding of stellar evolution, nucleo-synthesis and mixing processes, dust formation in stellar environments, and galactic chemical evolution. Pre-solar grains open a new observational window for astrophysical researches.

  11. Oak Ridge National Laboratory Research Reactor Experimenters' Guide

    Energy Technology Data Exchange (ETDEWEB)

    Cagle, C.D. (comp.)

    1982-10-01

    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.

  12. Oak Ridge National Laboratory Research Reactor Experimenters' Guide

    International Nuclear Information System (INIS)

    The Oak Ridge National Laboratory (ORNL) operates six research reactors dedicated to research and development work as well as radioisotope production. These reactors are used by ORNL and qualified non-ORNL research and development groups. The purpose of this report is to provide information to research personnel concerning the facilities and the ORNL research and services groups available to assist in the design, fabrication, operation, and post-operation examination of irradiation assemblies. Safety and operability reviews and quality assurance requirements are also described

  13. An Experimental Investigation of Secure Communication With Chaos Masking

    CERN Document Server

    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.

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

    OpenAIRE

    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...

  15. An Experimental Investigation of Secure Communication With Chaos Masking

    OpenAIRE

    Dhar, Sourav; Chakraborty, Kabir

    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 trans...

  16. New experimental tools for bioassays with whitefly in laboratory

    Directory of Open Access Journals (Sweden)

    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.

  17. Experimental investigation of stimulated Brillouin scattering in an amplified medium

    Energy Technology Data Exchange (ETDEWEB)

    Zel' dovich, B.Y.; Izotov, A.N.; Kapitskii, Y.E.; Krivoshchekov, V.A.; Mamaev, A.V.; Mel' nikov, N.A.; Pilipetskii, N.F.; Tabrin, V.N.; Shevelevich, R.S.; Shkunov, V.V.

    1985-09-01

    An experimental investigation was made of stimulated Brillouin scattering (STBS) in Nd/sup 3 +/-activated glass fibers. Optical pumping of these fibers at the wavelength of 1.06 ..mu.. resulted in amplification. Linear amplification in these fibers lowered the STBS threshold and increased the gain of conversion into a reflected Stokes wave.

  18. Experimental investigation of stimulated Brillouin scattering in an amplifying medium

    Energy Technology Data Exchange (ETDEWEB)

    Zeldovich, B.IA.; Izotov, A.N.,; Kapitskii, IU.E.; Krivoshchekov, V.A.; Mamaev, A.V.

    1985-09-01

    Stimulated Brillouin scattering (SBS) in Nd/sub 3/(+)-activated glass fibers has been investigated experimentally. Amplification in the medium at a wavelength of 1.86 microns was observed under optical pumping. It is shown that linear amplification in the medium reduced the SBS threshold and increased the gain into the reflected Stokes wave. 6 references.

  19. Investigating the Site of Newton's Laboratory in Trinity College, Cambridge

    OpenAIRE

    Spargo, P E

    2005-01-01

    It is not generally known that over the course of some thirty years, Isaac Newton carried out around four hundred chemical experiments in a private laboratory located in the walled garden immediately below his rooms in Trinity College, Cambridge. The exact location of his laboratory has long been a source of conjecture and this article describes a survey undertaken to determine both the possible site of the laboratory as well as that of the rubbish pit in which ...

  20. Laboratory investigations of arcing on W-coated graphite components

    Energy Technology Data Exchange (ETDEWEB)

    Laux, M., E-mail: michael.laux@ipp.mpg.de [Teilinstitut Greifswald, Wendelsteinstr. 1, D-17491 Greifswald (Germany); Siemroth, P.; Marx, M. [Arc Precision Sources, Coatings and Analysis GmbH, Bahnhofstr. 1, D-15745 Wildau (Germany); Neu, R.; Rohde, V.; Balden, M.; Endstrasser, N. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstr. 2, D-85748 Garching (Germany)

    2013-07-15

    Results of laboratory experiments of arcing on graphite tiles coated by a W-layer are reported. The samples have been taken from coated tiles manufactured for ASDEX Upgrade (AUG). The motion of the arcs was observed by high-speed cameras. Additionally, sample plates have been exposed to collect macro-particles emitted by the arc. The eroded surfaces of the cathodes were investigated after experiment to characterize surface changes, tracks, and re-deposited particles. On the cathode strongly radiating immobile spots are observed by the cameras acting as sources of numerous macro-particles. At the surface large holes (diameter 17 ?m) are found that perforate the W-layer and extend into the graphite bulk. Subsequent arcs tend to locate at the pre-existing holes. Hence, locally the W-coating is quickly and effectively broken, the W erosion is enhanced as compared to bulk W, and carbon is locally liberated despite the existence of an undamaged W-coating outside the arcing region.

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

    Science.gov (United States)

    Collette, A.; Meyer, G.; Malaspina, D.; Sternovsky, Z.

    2015-07-01

    We describe laboratory experiments which reproduce characteristic signals observed on spacecraft, believed to be caused by dust impact. A simulated spacecraft, including an antenna system using a facsimile of the preamplifier electronics from the STEREO/WAVES instrument, was bombarded by 10 km/s submicron-sized dust at the University of Colorado Institute for Modeling Plasma, Atmospheres, and Cosmic Dust accelerator facility. Signal variation was investigated as a function of the DC potentials of both the spacecraft and the antennas. We observed (1) signals corresponding to modification of the spacecraft body potential, an important process believed to be responsible for the so-called "triple hit" antenna signals on STEREO, (2) a few-eV energy distribution for the electrons and ions released in the impact leading to (3) signals corresponding to direct recollection of a substantial fraction of the impact charge by the spacecraft antennas, even at modest antenna bias potentials. We also observe (4) an unexpected class of fast antenna signals, which do not appear to be caused by charge recollection by either the spacecraft or the antennas and may be induced by charge separation in the expanding plasma cloud. Similar signals are also commonly observed by the STEREO/WAVES instrument but have not previously been analyzed.

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

    Energy Technology Data Exchange (ETDEWEB)

    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-dimensional similitude analysis are used to support the design, regarding the occurrence of two-phase flow instabilities. Some experimental results are presented in order to validate the current design. A full characterisation of the pressure drop losses in the facility is presented. Both, distributed and local pressure drop losses are investigated and the experimental results are compared with the main correlations used in the literature for the analysis of pressure drop in two-phase flow systems. Finally, pressure drop and density wave oscillations are studied experimentally, with main focus on the interaction of these two oscillation modes. In addition, the influence of compressibility volumes on the stability limits for the density wave phenomenon is analysed.(Author)

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

    Science.gov (United States)

    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 formulated requirements quite well, although not fully. It was also found that a visual programming language for instrumentation might have wider use in science education. The public domain programs of the prototype are available via Internet, in .

  4. Numerical and experimental investigation of vortical flow-flame interaction

    Energy Technology Data Exchange (ETDEWEB)

    Najm, H.N.; Schefer, R.W.; Milne, R.B.; Mueller, C.J. [Sandia National Labs., Livermore, CA (United States); Devine, K.D.; Kempka, S.N. [Sandia National Labs., Albuquerque, NM (United States)

    1998-02-01

    A massively parallel coupled Eulerian-Lagrangian low Mach number reacting flow code is developed and used to study the structure and dynamics of a forced planar buoyant jet flame in two dimensions. The numerical construction uses a finite difference scheme with adaptive mesh refinement for solving the scalar conservation equations, and the vortex method for the momentum equations, with the necessary coupling terms. The numerical model construction is presented, along with computational issues regarding the parallel implementation. An experimental acoustically forced planar jet burner apparatus is also developed and used to study the velocity and scalar fields in this flow, and to provide useful data for validation of the computed jet. Burner design and laser diagnostic details are discussed, along with the measured laboratory jet flame dynamics. The computed reacting jet flow is also presented, with focus on both large-scale outer buoyant structures and the lifted flame stabilization dynamics. A triple flame structure is observed at the flame base in the computed flow, as is theoretically expected, but was not observable with present diagnostic techniques in the laboratory flame. Computed and experimental results are compared, along with implications for model improvements.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Theoretical and experimental investigation of electron collisions with acetone

    Science.gov (United States)

    Homem, M. G. P.; Iga, I.; da Silva, L. A.; Ferraz, J. R.; Machado, L. E.; de Souza, G. L. C.; da Mata, V. A. S.; Brescansin, L. M.; Lucchese, R. R.; Lee, M.-T.

    2015-09-01

    We report a joint theoretical-experimental investigation on elastic electron scattering by acetone in the low- and intermediate-energy regions. More specifically, experimental differential, integral, and momentum-transfer cross sections are given in the 30-800 eV and 10?-120? ranges. Theoretical cross sections are reported in the 1-500 eV interval. The experimental differential cross sections were determined using a crossed electron-beam-molecular-beam geometry, whereas the absolute values of the cross sections were obtained using the relative-flow technique. Theoretically, a complex optical potential derived from a Hartree-Fock molecular wave function was used to represent the collision dynamics, and a single-center expansion method combined with the Padé approximant technique was used to solve the scattering equations. Our experimental cross-section data are in generally good agreement with the present calculated data. Also, our calculated grand-total and total absorption cross sections are in good agreement with the experimental results reported in the literature. Nevertheless, our calculations have revealed a strong shape resonance in the 2B2 scattering channel not clearly seen in the experimental results. Possible reasons for this fact are also discussed.

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

    International Nuclear Information System (INIS)

    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)

  8. Experimental Investigation for the Analysis of Cold-Recycled Bituminous Mixtures

    OpenAIRE

    Riviera, Pier Paolo; Chiappinelli, Giuseppe; Santagata, Ezio

    2007-01-01

    The Authors present the results obtained in a experimental investigation carried out to provide technical support to the construction of a cold-recycled bituminous sub-base layer of a major Italian motorway. Compliance of the employed materials and of the resulting recycled mixture to requirements set in Technical Specifications and to the adopted job-mix formula were verified by means of laboratory tests. Field observations focused on the evaluation of the void content of the compacted sub-b...

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

    International Nuclear Information System (INIS)

    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

  10. Scaled Laboratory Experimental Design of Radiation-Driven Cloud Implosions

    Science.gov (United States)

    Keiter, Paul; Stone, James; Trantham, Matt; Malamud, Guy; Klein, Sallee

    2014-10-01

    When hot, massive stars form they ionize and heat the surrounding interstellar medium (ISM), forming an expanding region of hot, high-radiation-pressure, ionized hydrogen gas called an H II region. The H II region itself can then induce further star formation. The two main mechanisms of star formation involving H II regions are collect and collapse [Elmegreen 1977] and radiation-driven implosions [Axford, 1964, Lefloch and Lazareff 1994]. Two persistent questions for this mechanism are when in the compression process and where in the cloud does star formation occur? Our understanding of stellar formation is based on computer simulations and models. To improve our understanding of these models, data are required. We present the design of a scaled experiment to study the interaction of an ionization front with a high-density sphere, which acts as a surrogate for the molecular cloud. Irradiating a high-Z foil with laser beams generates the ionization front. The ionization front will propagate in a low-density medium before interacting with the sphere. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0001840.

  11. Acute lung injury and acute respiratory distress syndrome: experimental and clinical investigations

    Directory of Open Access Journals (Sweden)

    Hsing I Chen

    2011-03-01

    Full Text Available Acute lung injury (ALI or acute respiratory distress syndrome (ARDS can be associated with various disorders. Recent investigation has involved clinical studies in collaboration with clinical investigators and pathologists on the pathogenetic mechanisms of ALI or ARDS caused by various disorders. This literature review includes a brief historical retrospective of ALI/ARDS, the neurogenic pulmonary edema due to head injury, the long-term experimental studies and clinical investigations from our laboratory, the detrimental role of NO, the risk factors, and the possible pathogenetic mechanisms as well as therapeutic regimen for ALI/ARDS.

  12. Laboratory investigation of crushed salt consolidation and fracture healing

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Laboratory investigation of crushed salt consolidation and fracture healing

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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 impacts of herbicides under natural conditions and studies identifying key factors determining the applicability of experimental results are urgently needed. PMID:26254767

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

    Science.gov (United States)

    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. Since previous work from our group has shown that the heterogeneous photooxidation of PAH occurs at different rates and via different mechanisms depending on its immediate environment, this in situ study of PAH reactivity provides substantial insight into the photochemical processing of this class of compounds in urban environments.

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

    Science.gov (United States)

    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.

  17. The Influence of Laboratory-Generated Tides on Experimental Deltas

    Science.gov (United States)

    Baumgardner, S. E.; Abeyta, A.; Cazanacli, D.; Paola, C.

    2013-12-01

    Due to their ecological and economic importance, deltas are widely studied but the controls on the processes that create and shape them are incompletely understood. The most prominent downstream control on a delta is the input of basinal energy from (wind-driven) waves and tides. Studies of the response of field-scale deltas to changing basinal energy conditions are limited by their large size and long response time. Laboratory-generated deltas allow control over upstream inputs (sediment and water) and base level, and enable the generation of a high-resolution record of topography and planform morphology of the deposit throughout the experiment. We include the effects of tides by imposing cyclic changes in base level with a period that is long compared to ordinary gravity waves but short compared to time scales of morphologic evolution; here we used periods of generated knickpoints, which led to channel deepening. These results suggest that basinal energy can affect deltaic processes far upstream of the coastline. We introduce waves to the system through the use of a generator; this generator produces waves with a single, user-defined period (here, ~1-2 seconds) and amplitude (2-3 cm) . The orientation of the incoming wave crests is set by the position of the generator. The addition of wave energy led to rapid shoreline retreat and straightening and the formation and migration of shore parallel barrier bars similar to what is observed in wave-influenced field-scale systems. Analysis of overhead imagery shows that wave transport of sediment occurs over a much shorter timescale than tidally-driven transport, leads to the formation of a continuous, coarse berm parallel to the shoreline and plays a major role in determining the configuration of channel mouths.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. The new low-level laboratory of the Arsenal Federal Experimental Plant

    International Nuclear Information System (INIS)

    At the Arsenal Federal Experimental Plant a new laboratory for measuring low level radioactivity concentrations has been installed. Measures taken to reduce the background as well as the equipment and the goals of the laboratory are shortly described. 1 tab. (qui)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    DEFF Research Database (Denmark)

    Kristensen, Lars; Zhang, Wenqi; Bay, Niels

    2000-01-01

    Resistance projection welding is widely used for joining of workpieces with almost any geometric combination. This makes standardization of projection welding impossible. In order to facilitate industrial applications of projection welding, systematic investigations are carried out on the geometric...... 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...... welding a disc to a ring with a triangular ring projection has been carried out to study the influence of the geometric parameters in various metal combinations. In these studies, SORPAS has been used as a supporting tool to understand the relationship of the parameters and the phenomena occurring in...

  2. Experimental and theoretical investigation of high gradient acceleration

    International Nuclear Information System (INIS)

    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

  3. Experimental investigation of contact resistance across pressed lead and aluminum

    International Nuclear Information System (INIS)

    In the proposed production of Accelerator Production of Tritium (APT) blanket module, lead will be encased in aluminum cladding. Energy transfer rate from the lead to the cooling water will be a function of the contact resistance between lead and aluminum. No data for contact resistance for this application exists in the literature. An experimental investigation has been conducted to determine thermal contact resistance between lead and aluminum in vacuum environment and also investigate the effect of pressure, surface roughness, and interface temperature on the contact resistance. The contact resistance decreases with the increase in contact pressure. Interface temperature and surface roughness do not affect the contact resistance significantly. There is slight increase in contact conductance with increasing temperature. The experimental results are generally well within acceptable accuracy and the data should be a good reference for the APT model

  4. Experimental and theoretical investigation of high gradient acceleration

    International Nuclear Information System (INIS)

    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

  5. Experimental investigations of thermal radiation from potassium atoms and design applications

    Science.gov (United States)

    Wang, C. S.; Chow, L. S. H.

    Theoretical models of thermal radiation from potassium-laden combustion gases show that thermal radiation from potassium atoms can contribute significantly to the radiant heat flux in radiant furnaces of steam generating systems. The potassium radiation is being investigated experimentally at Argonne National Laboratory. Experimental data were interpreted by a radiant heat transfer model that calculates the total gas emissivity and absorptivity from the spectral properties of CO2, H2O, and potassium atoms. The model was applied to provide design data for radiant furnaces of coal-fired magnetohydrodynamic (MHD) power generation systems, where considerable amount of potassium atoms would be present.

  6. Experimental investigation of the serum albumin fascia microstructure

    Science.gov (United States)

    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.

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

    OpenAIRE

    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 ...

  8. Experimental investigation of efficiency of a novel conical solar collector

    OpenAIRE

    MORAVEJ, M

    2015-01-01

    One of the methods to improvement of solar-to-thermal energy conversion is the design of geometry in solar collectors. In this paper, the new solar collector which is called solar conical collector has been designed and tested. The efficiency of solar conical collector was experimentally investigated by use of ASHRAE standard. Experiments were performed with water as a working fluid in the outdoor condition of Ahvaz city in the south of Iran. The results show that the average efficiency of a ...

  9. Experimental investigation of the elasticity of the human diaphragm

    OpenAIRE

    Kaemmer Daniel; Prescher Andreas; Hohl Christian; Steinau Gerhard; Böhm Gabriele

    2010-01-01

    Abstract Background Traumatic diaphragmatic ruptures affect mainly the left side. In an experimental study in human corpses we examined the stretch behaviour of the left and right diaphragmatic halves. Methods In a total of 8 male and 8 female corpses each diaphragmatic half was divided into 4 different segments. Each segments stretch behaviour was investigated. In steps of 2 N the stretch was increased up to 24 N. Results In the female the left diaphragm showed a stronger elasticity compared...

  10. Pain-avoidance versus reward-seeking: an experimental investigation

    OpenAIRE

    Claes, Nathalie; Crombez, Geert; Vlaeyen, Johan

    2015-01-01

    According to fear-avoidance models, a catastrophic interpretation of a painful experience may give rise to pain-related fear and avoidance, leading to the development and maintenance of chronic pain problems in the long term. However, little is known about how exactly motivation and goal prioritization play a role in the development of pain-related fear. The present study investigates these processes in healthy volunteers using an experimental context with multiple, competing goals. In a diff...

  11. Experimental Investigation of Energy Saving in Referigeration System

    OpenAIRE

    Inder Singh Nagar

    2014-01-01

    This Research deals with experimental investigation of energy saving in refrigeration system. We have all experienced a sensation of heat when passing behind a functioning refrigerator or air conditioner. The cause of this phenomenon is due to thr air condenser, a heat exchanger made up of tubes with air fins attached to the back of the device. This is where the cooling fluid condenses by releasing its heat into the ambient air. To utilize this heat, a water fine water droplet...

  12. Experimental investigation of streamer affinity for dielectric surfaces

    OpenAIRE

    Trienekens, D.J.M.; Nijdam, S; Akkermans, G.; Plompen, I.; Christen, T; Ebert, U.

    2015-01-01

    We have experimentally investigated the affinity of streamers for dielectric surfaces using stroboscopic imaging and stereo photography. Affinity of streamers for dielectric surfaces was found to depend on a wide set of parameters, including pressure, voltage, dielectric material and discharge gap geometry. Our results show that higher relative permittivity, higher pressure, lower voltage, an d asymmetrical sample placement increase the chance of the streamer followi...

  13. Incentives, decision frames, and motivation crowding out: an experimental investigation

    OpenAIRE

    Irlenbusch, Bernd; Sliwka, Dirk

    2005-01-01

    A simple principal agent problem is experimentally investigated in which a principal repeatedly sets a wage and an agent responds by choosing an effort level. The principal's payoff is determined by the agent's effort. In a first setting the principal can only set a fixed wage in each period. In a second setting the principal has the possibility to supplement the fixed wage with a piece rate. Surprisingly, efforts are lower in the case where piece rates can be paid. Furthermore, switching in ...

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

    OpenAIRE

    Romero E.

    2010-01-01

    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...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  16. Experimental investigation on SPS casing treatment with bias flow

    Directory of Open Access Journals (Sweden)

    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.

  17. Experimental Investigation of a W-Band Gyroklystron Amplifier

    Science.gov (United States)

    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 investigations on fiber laser color marking of steels

    International Nuclear Information System (INIS)

    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

  19. An experimental investigation of two-phase liquid oxygen pumping

    Science.gov (United States)

    Gross, L. A.

    1973-01-01

    The results of an experimental program to explore the feasibility of pumping two-phase oxygen (liquid and gas) at the pump inlet are reported. Twenty-one cavitation tests were run on a standard J-2 oxygen pump at the MSFC Components Test Laboratory. All tests were run with liquid oxygen 5 to 10 K above the normal boiling point temperature. During ten tests run at approximately at the pump inlet were noted before complete pump performance 50 percent of the nominal operating speed, two phase conditions were achieved. Vapor volumes of 40 to 50 percent at the pump inlet were noted before complete pump performance loss. The experimental results compared to predictions. Nine cavitation tests run at the nominal pump speed over a 5 K temperature range showed progressively lower net positive suction head (NPSH) requirements as temperature was increased. Two-phase operation was not achieved. The temperature varying NPSH data were used to calculate thermodynamic effects on NPSH, and the results were compared to existing data.

  20. Experimental investigation of defect criticality in FRP laminate composites

    Science.gov (United States)

    Joyce, Peter James

    1999-11-01

    This work examines the defect criticality of fiber reinforced polymer Composites. The objective is to determine the sensitivity of the finished composite to various process-induced defects. This work focuses on two different classes of process-induced defects; (1) fiber waviness in high performance carbon-fiber reinforced unidirectional composites and (2) void volume in low cost glass-fabric reinforced composites. The role of fiber waviness in the compressive response of unidirectional composites has been studied by a number of other investigators. Because of difficulties associated with producing real composites with varying levels of fiber waviness, most experimental studies of fiber waviness have evaluated composites with artificially induced fiber waviness. Furthermore, most experimental studies have been concentrated on the effects of out-of-plane fiber waviness. The objective of this work is to evaluate the effects of in-plane fiber waviness naturally occurring in autoclave consolidated thermoplastic laminates. The first phase of this project involved the development of a simple technique for measuring the resulting fiber waviness levels. An experimental investigation of the compression strength reduction in composites with in-plane fiber waviness followed. The experimental program included carbon-fiber reinforced thermoplastic composites manufactured from prepreg tape by hand layup, and carbon-fiber and glass-fiber reinforced composites manufactured from an experimental powder towpreg by filament winding and autoclave consolidation. The compression specimens exhibited kink band failure in the prepreg composite and varying amounts of longitudinal splitting and kink banding in the towpreg composites. The compression test results demonstrated the same trend as predicted by microbudding theory but the overall quantitative correlation was poor. The second thrust of this research evaluated void effects in resin transfer molded composites. Much of the existing literature in this area has focused on composites with unidirectional fiber reinforcement. In this program, the influence of void volume on the mechanical behavior of RTM composites with plain weave reinforcement was investigated. The experimental program demonstrated that the effects of void volume are negligible in terms of the fiber dominated properties. Interlaminar shear strength tests on the other hand demonstrated a linear dependence on void volume in the range tested.

  1. Experimental investigation of transient thermoelastic effects in dynamic fracture

    International Nuclear Information System (INIS)

    Thermoelastic effects in fracture are generally considered to be negligible at the benefit of the conversion of plastic work into heat. For the case of dynamic crack initiation, the experimental and theoretical emphasis has been put on the temperature rise associated with crack-tip plasticity. Nevertheless, earlier experimental work with polymers has shown that thermoelastic cooling precedes the temperature rise at the tip of a propagating crack (Fuller et al., 1975). Transient thermoelastic effects at the tip of a dynamically loaded crack have been theoretically assessed and shown to be significant when thermal conductivity is initially neglected. However, the fundamental question of the relation between crack initiation and thermal fields, both of transient nature, is still open. In this paper, we present an experimental investigation of the thermoelastic effect at the tip of fatigue cracks subjected to mixed-mode (dominant mode 1) dynamic loading. The material is commercial polymethylmethacrylate as an example of 'brittle' material. The applied loads, crack-tip temperatures and fracture time are simultaneously monitored to provide a more complete image of dynamic crack initiation. The corresponding evolution of the stress intensity factors is calculated by a hybrid-experimental numerical model. The results show that substantial crack-tip cooling develops initially to an extent which corroborates theoretical estimates. This effect is followed by a temperature rise. Fracture is shown to initiate during the early cooling phase, thus emphasizing the relevance of the phenomenon to dynamic crack initiation in this material as probably in other materials. (author)

  2. Experimental investigation of the MSFR molten salt reactor concept

    International Nuclear Information System (INIS)

    In the paper experimental modelling and investigation of the MSFR concept will be presented. MSFR is a homogeneous, single region liquid fuelled fast reactor concept. In case of molten salt reactors the core neutron flux and fission distribution is determined by the flow field through distribution and transport of fissile material and delayed neutron precursors. Since the MSFR core is a single region homogeneous volume without internal structures, it is a difficult task to ensure stable flow field, which is strongly coupled to the volumetric heat generation. These considerations suggest that experimental modelling would greatly help to understand the flow phenomena in such geometry. A scaled and segmented experimental mock-up of MSFR was designed and built in order to carry out particle image velocimetry measurements. Basic flow behaviour inside the core region can be investigated and the measurement data can also provide resource for the validation of computational fluid dynamics models. Measurement results of steady state conditions will be presented and discussed.

  3. Experimental Investigation into Electrical Discharge Machining of Stainless Steel 304

    Directory of Open Access Journals (Sweden)

    M.M. Rahman

    2011-01-01

    Full Text Available This study presents the experimental investigation of the machining characteristics of austenitic stainless steel 304 through electric discharge machining. The effectiveness of the EDM process with stainless steel is evaluated in terms of the removal rate (MRR, the Tool Wear Rate (TWR and the surface roughness of the work-piece produced. The experimental work is conducted utilizing Die Sinking electrical discharge machine of AQ55L model. Cylindrical copper electrode having a size of Ø19x37 mm and positive polarity for electrode (reverse polarity is used to machine austenitic stainless steel 304 materials. The work material holds tensile strength of 580 and 290 MPa as yield strength. The size of the work-piece was Ø22x30 mm. Investigations indicate that increasing the peak current increases the MRR and the surface roughness. The TWR increases with peak ampere until 150 ? sec pulse-on time. From the experimental results no tool wear condition is noted for copper electrode at long pulse-on time with reverse polarity. The optimal pulse-on time is changed with high ampere.

  4. A Computational and Experimental Investigation of Shear Coaxial Jet Atomization

    Science.gov (United States)

    Ibrahim, Essam A.; Kenny, R. Jeremy; Walker, Nathan B.

    2006-01-01

    The instability and subsequent atomization of a viscous liquid jet emanated into a high-pressure gaseous surrounding is studied both computationally and experimentally. Liquid water issued into nitrogen gas at elevated pressures is used to simulate the flow conditions in a coaxial shear injector element relevant to liquid propellant rocket engines. The theoretical analysis is based on a simplified mathematical formulation of the continuity and momentum equations in their conservative form. Numerical solutions of the governing equations subject to appropriate initial and boundary conditions are obtained via a robust finite difference scheme. The computations yield real-time evolution and subsequent breakup characteristics of the liquid jet. The experimental investigation utilizes a digital imaging technique to measure resultant drop sizes. Data were collected for liquid Reynolds number between 2,500 and 25,000, aerodynamic Weber number range of 50-500 and ambient gas pressures from 150 to 1200 psia. Comparison of the model predictions and experimental data for drop sizes at gas pressures of 150 and 300 psia reveal satisfactory agreement particularly for lower values of investigated Weber number. The present model is intended as a component of a practical tool to facilitate design and optimization of coaxial shear atomizers.

  5. An Adaptable Investigative Graduate Laboratory Course for Teaching Protein Purification

    Science.gov (United States)

    Carroll, Christopher W.; Keller, Lani C.

    2014-01-01

    This adaptable graduate laboratory course on protein purification offers students the opportunity to explore a wide range of techniques while allowing the instructor the freedom to incorporate their own personal research interests. The course design involves two sequential purification schemes performed in a single semester. The first part…

  6. LABORATORY INVESTIGATION AND ANALYSIS OF A GROUND-WATER FLOWMETER

    Science.gov (United States)

    The ground-water flowmeter system, model 30L, manufactured by K-V Associates, Inc., Falmouth, Massachusetts was tested under controlled laboratory conditions. The influence of slotted pipe schedule, slot orientation, backfill materials, endcap bags, isolated regions of high hydra...

  7. Students' Written Arguments in General Chemistry Laboratory Investigations

    Science.gov (United States)

    Choi, Aeran; Hand, Brian; Greenbowe, Thomas

    2013-01-01

    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…

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  10. Theoretical and experimental investigation of the thermoacoustic process

    Science.gov (United States)

    Babaei, Hadi

    This thesis presents a study of thermoacoustic processes. Thermoacoustic science, which can serve as a renewable and sustainable source of energy, involves thermoacoustic, acoustics and their interactions. This research investigated the thermoacoustic phenomenon through theoretical and experimental investigations. The theoretical study is comprised of two parts. The first part focused on the development of a comprehensive algorithm for the design, development and performance evaluation of thermoacoustic devices. The developed algorithm is capable of designing and optimizing individual thermoacoustic heat engines and refrigerators and coupled engine-refrigerator systems. In the second part of the theoretical study, the theoretical model of thermoacoustic couples predicting stack temperature difference was modified by incorporating more realistic physical processes that were consistent with practical applications. Significant improvement in the accuracy of the stack temperature difference predictions was observed with the modified model as compared to the previous models through experimental validation. Detailed experimental investigations were conducted to enhance the fundamental understanding of the thermo-fluid behavior in thermoacoustic couples. The first part of the experimental study was focused on the investigation of the influence of drive ratio and stack position on the stack temperature field. The results provided the first evidence of the two-dimensional temperature distribution on both end faces of the stack. A physical explanation for the change in the stack temperature difference profile from sinusoidal to sawtooth form with an increase in the drive ratio was provided.˙1t is concluded that the acoustic dissipation in the stack which influenced the stack cold-end temperature was responsible for this behavior. In the second part, experiments were conducted to investigate streaming velocity fields in a thermoacoustic device using a synchronized PIV technique. The results showed that not only the presence of a stack but also the type and geometrical characteristics of a stack can significantly change the structure and magnitude of acoustic streaming. For both stacks, the streaming velocity field in the region adjacent to the hot-end of the stack was stronger with higher spatio-temporal variations as compared to that adjacent to the cold-end of stack, at almost all the drive ratios. Key Words: thermoacoustic, energy, design, procedure, stack, streaming, temperature, Particle Image Velocimetry (PIV), performance.

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

    International Nuclear Information System (INIS)

    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

  12. Theoretical and Experimental Investigations of DNA Open States

    CERN Document Server

    Shigaev, A S; Lakhno, V D

    2014-01-01

    This research is a review and assay of literature data on the properties of DNA open states. The states result from large fluctuations of a duplex and have a great influence on a wide range of biochemical processes, including electric charge transfer in DNA. A comparative analysis of kinetic and thermodynamic experimental data on DNA open states has been performed for a wide temperature range. Apparent contradictions between the data of different experiments have been explained. Based on differences in thermodynamic properties and other characteristics three different types of DNA open states have been identified; a modern definition of the term "open state" has been given. A brief review of simple mathematical models of DNA has been presented; in most of the models the state of every base pair is defined by one or two variables. The central problems of investigation of heterogeneous DNA within the approaches of the level considered are examined. The roles of every model group in experimental data interpretat...

  13. Experimental Investigation of Creep Behavior of Reactor Vessel Lower Head

    International Nuclear Information System (INIS)

    The authors report a study which aimed at experimentally and numerically investigating and characterizing the failure of a reactor pressure vessel (RPV) lower head due to thermal and pressure loads generated by a severe accident. They present the experimental apparatus which is based on a scaled version of the lower part of a TMI-like reactor pressure vessel without vessel skirt. They report and comment the results obtained during the first five experiments: uniform heating and non penetrations, centre-peaked heat flux and no penetrations, edge-peaked heat flux and no penetrations, uniform heating with penetrations, edge-peaked heat flux with penetrations. They compare the third and fifth experience (those with edge-peaked heat flux)

  14. Experimental investigation of cyclic hygrothermal aging of hybrid composite

    KAUST Repository

    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.

  15. Antirelaxation coatings in coherent spectroscopy: Theoretical investigation and experimental test

    Science.gov (United States)

    Nasyrov, K.; Gozzini, S.; Lucchesini, A.; Marinelli, C.; Gateva, S.; Cartaleva, S.; Marmugi, L.

    2015-10-01

    We describe a theoretical model, based on a density matrix and the Liouville equation, for the investigation of magneto-optical resonances in alkali-metal atomic vapor, in particular in the case of the electromagnetically induced transparency (EIT) in the presence of antirelaxation coatings. The influence of the coating is parametrized with an empirical coefficient describing its efficiency; the calculations are extended to a broad range of coating quality, contrary to previous works, and to uncoated cells. The model takes into account also different configurations for the EIT formation and different efficiency of optical pumping, as determined by the coating characteristics and the atomic energy structure. The model is validated by investigating the EIT with degenerate Zeeman levels in 39K D1 and Cs D2 lines, which exhibit respectively an almost negligible and a relevant impact of hyperfine optical pumping. The results are compared to experimental data, exhibiting good agreement; in particular, for the 39K D1 line, recent findings are shown here in the case of degenerate and nondegenerate EIT with amplitude-modulated light. Our results demonstrate an effective approach for the investigation of antirelaxation coatings and their contribution in the formation of magneto-optical resonances in alkali-metal atoms, in different regimes and with largely different efficiencies. This sheds new light on well-known but not yet entirely clarified phenomena and their behavior as a function of experimental parameters.

  16. Counter-Top Thermoacoustic Refrigerator- An Experimental Investigation

    International Nuclear Information System (INIS)

    Thermoacoustic phenomenon is a new alternative refrigeration technology. Though design and fabrication is complex for getting the desired effect, it is environmentally friendly and successful system showed that it is relatively easy to run compared to the traditional vapor compression refrigeration system. Currently, theories supporting the thermoacoustic refrigeration systems are yet to be comprehensive to make them commercially viable. Theoretical, experimental, and numerical studies are being done to address the thermodynamics-acoustics interactions. In this study, experimental investigations were completed to test the feasibility of the practical use of a thermoacoustic refrigerator in its counter-top form for future specific application. The system was designed and fabricated based on linear acoustic theory. Acoustic power was given by a loud speaker and thermoacoustic effects were measured in terms of the cooling effects produced at resonanance. Investigations showed that discrepancies between designed and working resonance frequency exist. Thermoacoutic cooling improved at a certain frequency, achieved when the working frequency was varied away from the design frequency. A cooling effect of 4.8 K below the ambient temperature of 23.3 deg. C was obtained from the counter-top thermoacoustic system. This system uses no refrigerants and no compressor to generate the cooling effect, a potential to be further investigated for a practical system.

  17. Laboratory prototype for experimental validation of MR-guided radiofrequency head and neck hyperthermia

    Science.gov (United States)

    Paulides, M. M.; Bakker, J. F.; Hofstetter, L. W.; Numan, W. C. M.; Pellicer, R.; Fiveland, E. W.; Tarasek, M.; Houston, G. C.; van Rhoon, G. C.; Yeo, D. T. B.; Kotek, G.

    2014-05-01

    Clinical studies have established a strong benefit from adjuvant mild hyperthermia (HT) to radio- and chemotherapy for many tumor sites, including the head and neck (H&N). The recently developed HYPERcollar allows the application of local radiofrequency HT to tumors in the entire H&N. Treatment quality is optimized using electromagnetic and thermal simulators and, whenever placement risk is tolerable, assessed using invasively placed thermometers. To replace the current invasive procedure, we are investigating whether magnetic resonance (MR) thermometry can be exploited for continuous and 3D thermal dose assessment. In this work, we used our simulation tools to design an MR compatible laboratory prototype applicator. By simulations and measurements, we showed that the redesigned patch antennas are well matched to 50 ? (S11fat/muscle phantom. Temperature measurements using the MR scanner confirmed the focused heating capabilities and MR compatibility of the setup. We conclude that the laboratory applicator provides the possibility for experimental assessment of the feasibility of hybrid MR-HT in the H&N region. This versatile design allows rigorous analysis of MR thermometry accuracy in increasingly complex phantoms that mimic patients' anatomies and thermodynamic characteristics.

  18. Laboratory prototype for experimental validation of MR-guided radiofrequency head and neck hyperthermia

    International Nuclear Information System (INIS)

    Clinical studies have established a strong benefit from adjuvant mild hyperthermia (HT) to radio- and chemotherapy for many tumor sites, including the head and neck (H and N). The recently developed HYPERcollar allows the application of local radiofrequency HT to tumors in the entire H and N. Treatment quality is optimized using electromagnetic and thermal simulators and, whenever placement risk is tolerable, assessed using invasively placed thermometers. To replace the current invasive procedure, we are investigating whether magnetic resonance (MR) thermometry can be exploited for continuous and 3D thermal dose assessment. In this work, we used our simulation tools to design an MR compatible laboratory prototype applicator. By simulations and measurements, we showed that the redesigned patch antennas are well matched to 50 ? (S11laboratory applicator provides the possibility for experimental assessment of the feasibility of hybrid MR-HT in the H and N region. This versatile design allows rigorous analysis of MR thermometry accuracy in increasingly complex phantoms that mimic patients' anatomies and thermodynamic characteristics. (paper)

  19. Investigation of impact crater processes using experimental and numerical techniques

    Science.gov (United States)

    Baldwin, Emily Clare

    2008-12-01

    Impact events throughout the history of the Solar System have occurred at all scales, from craters produced by the hypervelocity impact of cosmic dust observed on lunar return samples, to the giant planet-sculpting impacts that have shaped the solid bodies of the Solar System. Investigating the impact process in the laboratory allows us to understand crater formation at a small scale where strength effects dominate however, it is difficult to scale directly to planetary sized impacts because gravity governs the cratering process at this large scale. Through computer modeling, it is possible to bridge the gap from small to large scale impact events. The influence of target porosity, saturation and an overlying water layer on crater morphology is investigated in the laboratory using a two-stage light gas gun to fire 1 mm diameter stainless steel projectiles at 5 km s"1 into sandstone targets. Larger craters were formed in the higher porosity targets and saturated targets. A critical water depth of 11.6 0.5 times the projectile diameter was required to prevent cratering in an unsaturated target, compared with 12.7 0.6 for saturated targets. The sensitivity of this critical water depth to impact velocity, projectile diameter and density is examined through use of the AUTODYN numerical code, for both laboratory and planetary scale impact events. Projectile survivability into water and sand targets is investigated in the lab for stainless steel and shale projectiles impacting at 2-5 km s"1 up to 30% of the projectile is found to survive. AUTODYN simulations show that basalt or sandstone meteorites impacting a simulated lunar surface survive the impact at velocities SMART-1 spacecraft into the Moon. Finally, lunar and terrestrial impact events are simulated in order to quantify the depth' of excavation as a function of transient crater diameter for a range of crater and basin sizes. The output is found to lie in the range 0.08-0.15, with the South Pole Aitken basin excavating material to a depth comparable to the thickness of the farside crust.

  20. Experimental Investigation of a Novel Blast Wave Mitigation Device

    OpenAIRE

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

    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 ...

  1. Experimental Investigation on Admittance-Based Piezoelectric Sensor Diagnostic Process

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Hyejin; Park, Tongil; Park, Gyuhae [Chonnam National University, Gwangju (Korea, Republic of)

    2015-01-15

    Structural health monitoring (SHM) techniques based on the use of active-sensing piezoelectric (PZT) materials have received considerable attention. The validation of the PZT functionality during SHM operation is critical to successfully implementing a reliable SHM system. In this study, we investigated several parameters that affect the admittance-based sensor diagnostic process. We experimentally identified the temperature dependency of the active-sensor diagnostic process. We found that the admittance-based sensor diagnostic process can differentiate the adhesion conditions of bonding materials that are used to install a PZT on a structure, which is important when designing a sensor diagnostic process for an SHM system.

  2. Experimental Investigation on Strength Characteristics of Binary Blended Concrete

    OpenAIRE

    MD. Hashmath; Toufeeq Anwar

    2014-01-01

    An experimental investigation has been carried out to assess the behavior of concrete beams blended with steel crimped fiber and flyash subjected to combined torsion-bending-shear with longitudinal reinforcement. The concrete is binary blended with 15% of fly ash by weight of cement as partial replacement of cement and addition of 0%, 0.5%, 0.75%, 1% of crimped steel fibers with aspect ratio of 80 are used for the study purpose. Compressive strength of concrete is measured by test...

  3. Experimental Investigation on Admittance-Based Piezoelectric Sensor Diagnostic Process

    International Nuclear Information System (INIS)

    Structural health monitoring (SHM) techniques based on the use of active-sensing piezoelectric (PZT) materials have received considerable attention. The validation of the PZT functionality during SHM operation is critical to successfully implementing a reliable SHM system. In this study, we investigated several parameters that affect the admittance-based sensor diagnostic process. We experimentally identified the temperature dependency of the active-sensor diagnostic process. We found that the admittance-based sensor diagnostic process can differentiate the adhesion conditions of bonding materials that are used to install a PZT on a structure, which is important when designing a sensor diagnostic process for an SHM system

  4. Preliminary experimental investigation of boundary layer in decelerating flow

    Directory of Open Access Journals (Sweden)

    P?íhoda J.

    2013-04-01

    Full Text Available Investigations of characteristics of turbulence inside boundary layer under decelerating flow were studied by means of constant temperature anemometer. The decelerating flow was simulated in the closed circuit wind tunnel 0.9 m × 0.5 m at IT AS CR. The free stream turbulence was either natural o risen up by square mesh plane grid. The details of experimental settings and measurement procedures of the instantaneous longitudinal velocity component are described and the distributions of intensity, skewness and kurtosis of turbulent fluctuations are discussed in the contribution.

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

    DEFF Research Database (Denmark)

    Dela Stang, B.; Isaksson, T.

    2002-01-01

    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 issue in studies of system effects.

  6. Experimental investigation of edge localised modes in JET

    International Nuclear Information System (INIS)

    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.)

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

    OpenAIRE

    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...

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

    International Nuclear Information System (INIS)

    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 zoneclose quotes of the Tiva Canyon member of the Paintbrush Tuff near Wren Wash on Yucca Mountain. 10 refs., 12 figs

  9. Experimental investigation of a unique airbreathing pulsed laser propulsion concept

    Science.gov (United States)

    Myrabo, L. N.; Nagamatsu, H. T.; Manka, C.; Lyons, P. W.; Jones, R. A.

    1991-01-01

    Investigations were conducted into unique methods of converting pulsed laser energy into propulsive thrust across a flat impulse surface under atmospheric conditions. The propulsion experiments were performed with a 1-micron neodymium-glass laser at the Space Plasma Branch of the Naval Research Laboratory. Laser-induced impulse was measured dynamically by ballistic pendulums and statically using piezoelectric pressure transducers on a stationary impulse surface. The principal goal was to explore methods for increasing the impulse coupling performance of airbreathing laser-propulsion engines. A magnetohydrodynamic thrust augmentation effect was discovered when a tesla-level magnetic field was applied perpendicular to the impulse surface. The impulse coupling coefficient performance doubled and continued to improve with increasing laser-pulse energies. The resultant performance of 180 to 200 N-s/MJ was found to be comparable to that of the earliest afterburning turbojets.

  10. Experimental Investigation of Microwave Waveform Interactions with DC Plasma Discharge

    Science.gov (United States)

    Vela, Russell; Sotnikov, Vladimir; Wallerstein, Austin; Mudaliar, Saba; Plechaty, Christopher; Caplinger, James; Main, Daniel; Kim, Tony

    2014-10-01

    The parametric interaction of microwaves in plasma discharges is a continuing area of interest to the Air Force Research Laboratory. While early investigations usually focused on continuous wave interactions with scaled ionospheric plasma parameters, this presentation will focus on sensor-centric microwave waveforms, and their coupling in a discharge produced plasma. As a baseline for future comparison, a DC plasma discharge, maintained in the glow discharge regime, will be utilized. To analyze the plasma based distortions on sensor-centric waveforms, sensor techniques such as the degradation of the signal, the traditional signal processing, and interaction by-products will be examined. Background on the individual waveforms, the plasma parameter sets, and a microwave based approach to the signal characterization will also be provided.

  11. Experimentally investigate ionospheric depletion chemicals in artificially created ionosphere

    International Nuclear Information System (INIS)

    A new approach for investigating ionosphere chemical depletion in the laboratory is introduced. Air glow discharge plasma closely resembling the ionosphere in both composition and chemical reactions is used as the artificially created ionosphere. The ionospheric depletion experiment is accomplished by releasing chemicals such as SF6, CCl2F2, and CO2 into the model discharge. The evolution of the electron density is investigated by varying the plasma pressure and input power. It is found that the negative ion (SF6?, CCl2F2?) intermediary species provide larger reduction of the electron density than the positive ion (CO2+) intermediary species. The negative ion intermediary species are also more efficient in producing ionospheric holes because of their fast reaction rates. Airglow enhancement attributed to SF6 and CO2 releases agrees well with the published data. Compared to the traditional methods, the new scheme is simpler to use, both in the release of chemicals and in the electron density measurements. It is therefore more efficient for investigating the release of chemicals in the ionosphere.

  12. Experimental investigation of transitional flow in a toroidal pipe

    CERN Document Server

    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. Experimental investigation of active loads control for aircraft landing gear

    Science.gov (United States)

    Mcgehee, J. R.; Dreher, R. C.

    1982-01-01

    Aircraft dynamic loads and vibrations resulting from landing impact and from runway and taxiway unevenness are recognized as significant in causing fatigue damage, dynamic stress on the airframe, crew and passenger discomfort, and reduction of the pilot's ability to control the aircraft during ground operations. One potential method for improving operational characteistics of aircraft on the ground is the application of active control technology to the landing gears to reduce ground loads applied to the airframe. An experimental investigation was conducted which simulated the landing dynamics of a light airplane to determine the feasibility and potential of a series hydraulic active control main landing gear. The experiments involved a passive gear and an active control gear. Results of this investigation show that a series hydraulically controlled gear is feasible and that such a gear is very effective in reducing the loads transmitted by the gear to the airframe during ground operations.

  14. Experimental Investigation of Sulphur Removal from LPG: New Aspect

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Memar Kazerooni

    2016-01-01

    Full Text Available Nano catalytic sulphur removal process is surveyed in this research, experimentally. Qualification of sulphur removal from liquefied natural gas process is investigated due to catalytic bed geometries which contains nano ferrite oxide and operation conditions. The purpose of experiments is finding the conditions which lead to the lowest amount of sulphur content in the out stream. Fraction of sulphur content in the outlet to the amount of sulphur in the inlet is considered as the operation criteria in this work. The effects of operating conditions such as operating temperature and pressure, the amount of sulphur concentration in feed stream, size of nano catalyst, the bed diameter and bed height are investigated. The different correlations with high confidence factor are introduced in this paper. Results show the diameter changes from 1-2 cm and the ratio of C/C0 changes from 0.05-0.03.

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

    Directory of Open Access Journals (Sweden)

    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 and then the erosive wear was investigated.Originality/value: The investigations of effects of external loads on erosive wear.

  16. Experimental and Numerical Investigations in Single Point Incremental Sheet Forming

    International Nuclear Information System (INIS)

    As recent studies introduced Incremental Sheet Forming (ISF) process as a very promising technology to manufacture sheet metal parts by the CNC controlled movement of a simple generative tool, industrial interests on ISF have increased. Indeed, due to its various advantages, such process has been demonstrated as an alternative to reduce costs resulting from stamping technology when small batches or prototypes have to be manufactured. Nevertheless, the process still needs further developments. A process analysis based on experimental and numerical investigations is required to carefully analyze the capabilities of the process and to consolidate its application in sheet metal industries. Starting from experimental results on standard components to show the interest of ISF, an application is carried out accounting flexibility of the process linked to the fact that the punches or dies are avoided and preliminary results have been obtained through experimental tests to manufacture micro parts. At the same time, a FEM analysis has been carried out in order to get the characteristics of the formed parts. In order to study the control of the process, a first study is carried out to perform an on-line sheet thickness measurement

  17. Experimental investigation on microbubble emission boiling heat transfer

    International Nuclear Information System (INIS)

    Microbubble emission boiling (MEB) is a phenomenon that the heat flux increases more rapidly compared to the critical heat flux (CHF) with a little increase of the heating surface superheat. A subcooled pool boiling experimental setup was built up to investigate the bubble behaviors of MEB under the atmospheric condition at different liquid subcooling with the help of high-speed video camera. The heating element of the experimental setup is a copper block with its upper part of a 10 mm diameter cylinder. The experimental results show that, in MEB regime, an unsteady vapor film spreads on the heating surface. Numerous microbubbles are emitted into subcooled liquid continuously with an extremely high speed from the interface. Along with the rise of heat flux, the oscillation period of vapor film along its thickness gets shorter and the maximum thickness also becomes smaller. The microbubble diameter under higher power heating is much smaller than that under low heating flux. The maximum heat flux in the experiment is about 9 MW/m2 at 60 K subcooling. (authors)

  18. Experimental investigation of streamer radius and length in SF6

    Science.gov (United States)

    Bujotzek, M.; Seeger, M.; Schmidt, F.; Koch, M.; Franck, C.

    2015-06-01

    SF6 has for decades been widely used in high voltage insulation and switching applications, e.g. in gas insulated switchgear. Despite its widespread use some important parameters, like the properties of streamers, are still not sufficiently understood. Since breakdown in SF6 always occurs via the streamer-leader transition the streamer properties are decisive for leader inception and, therefore, breakdown of the insulation. Important parameters are, for example, the streamer radius and the streamer propagation length of arrested streamers. Such properties enter in breakdown prediction models. In the present study the streamer radius and the propagation length were investigated experimentally at 50 and 100?kPa for both polarities using strongly and weakly non-uniform background fields. No experimental information was available so far for negative polarity. The resulting streamer radius scaling agrees with previous experimental results for positive polarity and with expectations from breakdown models for negative polarity. These results were similar for strongly non-uniform and weakly non-uniform background fields. A difference between the two setups was observed for the streamer lengths. It was found that for strongly non-uniform fields the streamer length scales as expected with the critical electric field but with a different field for weakly non-uniform background fields. This was similar for both polarities.

  19. Space Weathering in Houston: A Role for the Experimental Impact Laboratory at JSC

    Science.gov (United States)

    Cintala, M. J.; Keller, L. P.; Christoffersen, R.; Hoerz, F.

    2015-01-01

    The effective investigation of space weathering demands an interdisciplinary approach that is at least as diversified as any other in planetary science. Because it is a macroscopic process affecting all bodies in the solar system, impact and its resulting shock effects must be given detailed attention in this regard. Direct observation of the effects of impact is most readily done for the Moon, but it still remains difficult for other bodies in the solar system. Analyses of meteorites and precious returned samples provide clues for space weathering on asteroids, but many deductions arising from those studies must still be considered circumstantial. Theoretical work is also indispensable, but it can only go as far as the sometimes meager data allow. Experimentation, however, can permit near real-time study of myriad processes that could contribute to space weathering. This contribution describes some of the capabilities of the Johnson Space Center's Experimental Impact Laboratory (EIL) and how they might help in understanding the space weathering process.

  20. Promising lines of investigations in the realms of laboratory astrophysics with the aid of powerful lasers

    Energy Technology Data Exchange (ETDEWEB)

    Belyaev, V. S., E-mail: belyaev@tsniimash.ru; Batishchev, P. A.; Bolshakov, V. V.; Elkin, K. S.; Karabadzhak, G. F.; Kovkov, D. V.; Matafonov, A. P.; Raykunov, G. G.; Yakhin, R. A. [Russian Space Agency, Central Research Institute of Machine Building (TsNIIMash) (Russian Federation); Pikuz, S. A.; Skobelev, I. Yu.; Faenov, A. Ya.; Fortov, V. E. [Russian Academy of Sciences (IVTAN), Joint Institute for High Temperatures (Russian Federation); Krainov, V. P. [Moscow Institute of Physics and Technology (State University) (Russian Federation); Rozanov, V. B. [Russian Academy of Sciences, Lebedev Institute of Physics (Russian Federation)

    2013-04-15

    The results of work on choosing and substantiating promising lines of research in the realms of laboratory astrophysics with the aid of powerful lasers are presented. These lines of research are determined by the possibility of simulating, under laboratory conditions, problematic processes of presentday astrophysics, such as (i) the generation and evolution of electromagnetic fields in cosmic space and the role of magnetic fields there at various spatial scales; (ii) the mechanisms of formation and evolution of cosmic gamma-ray bursts and relativistic jets; (iii) plasma instabilities in cosmic space and astrophysical objects, plasma jets, and shock waves; (iv) supernova explosions and mechanisms of the explosion of supernovae featuring a collapsing core; (v) nuclear processes in astrophysical objects; (vi) cosmic rays and mechanisms of their production and acceleration to high energies; and (vii) astrophysical sources of x-ray radiation. It is shown that the use of existing powerful lasers characterized by an intensity in the range of 10{sup 18}-10{sup 22} W/cm{sup 2} and a pulse duration of 0.1 to 1 ps and high-energy lasers characterized by an energy in excess of 1 kJ and a pulse duration of 1 to 10 ns makes it possible to perform investigations in laboratory astrophysics along all of the chosen promising lines. The results obtained by experimentally investigating laser plasma with the aid of the laser facility created at Central Research Institute of Machine Building (TsNIIMash) and characterized by a power level of 10 TW demonstrate the potential of such facilities for performing a number of experiments in the realms of laboratory astrophysics.

  1. Experimental investigation of buried tritium in plant and animal tissues

    International Nuclear Information System (INIS)

    Buried exchangeable tritium appears as part of organically bound tritium (OBT) in the traditional experimental determination of OBT. Since buried tritium quickly exchanges with hydrogen atoms in the body following ingestion, assuming that it is part of OBT rather than part of tritiated water (HTO) could result in a significant overestimate of the ingestion dose. This paper documents an experimental investigation into the existence, amount and significance of buried tritium in plant and fish samples. OBT concentrations in the samples were determined in the traditional way and also following denaturing with five chemical solutions that break down large molecules and expose buried tritium to exchange with free hydrogen atoms. A comparison of the OBT concentrations before and after denaturing, together with the concentration of HTO in the supernatant obtained after denaturing, suggests that buried OBT may exist but makes up less than 5% of the OBT concentration in plants and at most 20% of the OBT concentration in fish. The effects of rinse time and rinse water volumes were investigated to optimize the removal of exchangeable OBT from the samples. (authors)

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

    Science.gov (United States)

    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.

  3. Experimental Investigations of Hydrogen Purification by Purging through Metal Hydride

    Directory of Open Access Journals (Sweden)

    Blinov D.V.

    2012-08-01

    Full Text Available In an experimental stand [1] for investigation of properties of hydrogen accumulating the materials investigated a new type of reactor cleaning and storage of hydrogen. The applicability of hydrogen purging through metal hydride beds for the purification from non-poisoning admixtures is studied experimentally. The main characteristics of the process together with the main technical barriers of the proposed technology are defined. Specially designed stainless steel continuous flow reactor filled with LaFe0.1Mn0.3Ni4.8 intermetallic compound is tested at variable inlet hydrogen/inert gas composition with measuring mass flow, pressure, temperature and hydrogen content at the outlet both for charging and discharging mode. The estimations of hydrogen losses and purification capacity show certain advantages of the studied technology in comparison with PSA-like mode [1], especially from the point of view of operation regime simplification. The evident process slow-down observed in the experiment is connected with saturation of metal hydride porous bed by hydrogen and with temperature increase due to high thermal effect at sorption (~ 40 kJ/mole ?2. The ways for heat and mass transfer optimization together with the range of applicability of the method for fine hydrogen purification are described and discussed.

  4. Experimental investigation of a dual purpose solar heating system

    International Nuclear Information System (INIS)

    Highlights: • A dual purpose water and air heating system experimentally investigated. • This system can be used to heat water and air simultaneously. • Water can be used as a PCM material for heating air through the night. • Dual purpose systems achieve greater efficiency and lower heat dissipation. • Average efficiency of dual purpose system is 4% higher than single purpose system. - Abstract: In this study, a dual purpose water and air heating system is experimentally investigated. The system consists of a dual purpose flat solar collector and a vertical water storage tank. Water and air have natural and forced convection in the collector, respectively. The reason why dual purpose systems are used is to achieve greater efficiency and lower heat dissipation. Furthermore, high temperature and high performance can be obtained using this solar collector. These systems can be used to heat water and air simultaneously or separately. The hot water can be utilized for domestic applications or as a PCM material for heating air through the night. Besides, the hot air can be used in air conditioning systems, industrial processes and dryers. Therefore, using these collectors brings high energy savings. Absorber plate temperature variation, storage tank average temperature, system efficiency and air velocity effects are presented. Moreover, hourly efficiency is compared for single purpose and dual purpose systems. The results indicate that the efficiency of the dual purpose system is 3 to 5% higher than a single purpose system

  5. Experimental and theoretical investigation of high gradient acceleration

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-02-01

    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.

  6. Experimental investigation of a packed bed thermal energy storage system

    Science.gov (United States)

    Cascetta, Mario; Cau, Giorgio; Puddu, Pierpaolo; Serra, Fabio

    2015-11-01

    In this work experimental investigations on a thermal energy storage system with a solid material as storage media and air as heat transfer fluid will be presented. The experimental test rig, installed at the DIMCM of the University of Cagliari, consists of a carbon steel tank filled with freely poured alumina beads that allows investigations of heat transfer phenomena in packed beds. The aim of this work is to show the influence of the operating conditions and physical parameters on thermocline formation and, in particular, the thermal behaviour of the thermal energy storage for repeated charging and discharging cycles. Better charging efficiency is obtained for lower values of mass flow rate and maximum air temperature and for increasing aspect ratio. A decreasing influence of the metal wall with continuous operation is also highlighted. In conclusion, the analysis focuses on the thermal hysteresis phenomenon, which causes degradation of the thermocline and the reduction of the energy that can be stored by the accumulator as the repeated number of cycles increases.

  7. Baseline experimental investigation of an electrohydrodynamically assisted heat pipe

    Science.gov (United States)

    Duncan, A. B.

    1995-07-01

    The increases in power demand and associated thermal management requirements of future space programs such as potential Lunar/Mars missions will require enhancing the operating efficiencies of thermal management devices. Currently, the use of electrohydrodynamically (EHD) assisted thermal control devices is under consideration as a potential method of increasing thermal management system capacity. The objectives of the currently described investigation included completing build-up of the EHD-Assisted Heat Pipe Test bed, developing test procedures for an experimental evaluation of the unassisted heat pipe, developing an analytical model capable of predicting the performance limits of the unassisted heat pipe, and obtaining experimental data which would define the performance characteristics of the unassisted heat pipe. The information obtained in the currently proposed study will be used in order to provide extensive comparisons with the EHD-assisted performance observations to be obtained during the continuing investigation of EHD-Assisted heat transfer devices. Through comparisons of the baseline test bed data and the EHD assisted test bed data, accurate insight into the performance enhancing characteristics of EHD augmentation may be obtained. This may lead to optimization, development, and implementation of EHD technology for future space programs.

  8. Combined analytical and experimental investigations for LWR containment phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Allielein, Hans Josef; Belt, Alexander; Broxtermann, Philipp [Institute of Reactor Safety and Reactor Technology LRST, RWTH Aachen University, Aachen (Germany); Reinecke, Ernst Arndt; Kelm, Stephan [Institute of Energy and Climate Research IEK-6, Julich (Germany)

    2012-04-15

    Main focus of the combined nuclear research activities at Aachen University (RWTH) and the Research Center Julich (JULICH) is the experimental and analytical investigation of containment phenomena and processes. We are deeply convinced that reliable simulations for operation, design basis and beyond-design basis accidents of nuclear power plants need the application of so-called lumped-parameter (LP) based codes as well as computational fluid dynamics (CFD) codes in an indispensable manner. The LP code being used at our institutions is the GRS code COCOSYS and the CFD tool is ANSYS CFX mostly used in German nuclear research. Both codes are applied for safety analyses especially of beyond design accidents. Focal point of the work is containment thermal-hydraulics, but source term relevant investigations for aerosol and iodine behavior are performed as well. To increase the capability of COCOSYS and CFX detailed models for specific features, e.g. recombiner behavior including chimney effect, building condenser, and wall condensation are developed and validated against facilities at different scales. The close connection between analytical and experimental activities is notable and identifying feature of the RWTH/JULICH activities.

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

    International Nuclear Information System (INIS)

    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

  10. How important are the dermatophytes? A clinical and laboratory investigation.

    OpenAIRE

    Davies, D. G.; Deighton, J.; Paterson, W D

    1982-01-01

    Dermatophyte infections were established in 6.9% of 640 unselected dermatology outpatients attending two district general hospitals in Cumbria over a six-month period. A clinical diagnosis of ringworm was confirmed in the laboratory in 43.1% of hospital and in 21.8% of a smaller series of general practice patients. No result of similar surveys have been published before., Even in a major stock-rearing area such as this, domestic pets appear to be a more important source of infection than the ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  13. Laboratory Experimental System for Examination of Acoustic Emission Generated by Partial Discharges

    Directory of Open Access Journals (Sweden)

    I. M. Salom

    2013-11-01

    Full Text Available One of the major causes of transformer failures is dielectric breakdown. Partial discharges cause gradual insulation degradation thus partial discharge activity monitoring provides transformer state insight. This paper gives an overview of common methods for partial discharges detection and source location in transformers, with a special reference to the acoustic method as an noninvasive and interference resistant method suitable for application. For laboratory testing a laboratory experimental system for partial discharge diagnostics using acoustic emission measurement was developed.

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

    Science.gov (United States)

    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…

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Experimental investigations of heated sources localization by acoustic brightness thermograph with focused antenna

    Science.gov (United States)

    Krotov, Eugene V.; Vilkov, Vladimir A.; Mansfeld, Anatoly D.; Reyman, Alexander M.

    2002-07-01

    Method of acoustical thermometry based on the registration of acoustical radiation produced by thermal motion of atoms and molecules allows mapping internal temperature field inside biological tissues. Investigations in this area are directed to the improvement of receiving methods and processing algorithms. Present paper is devoted to the investigation of one method of acoustical radiation measurement using acoustical thermograph with focused antenna. An operating laboratory prototype of acoustical thermograph is described. The results of experimentally measured receiving field of focused antenna in focal plane are presented. The possibility of localization of heated sources by means of acoustical thermograph with focused antenna has been demonstrated experimentally. This work was supported by RFBR and 6th competitive expertise of RAS young scientists.

  17. Role of routine laboratory investigations in preoperative evaluation

    OpenAIRE

    Kumar, Aditya; srivastava, Uma

    2011-01-01

    Traditionally, routine investigations prior to surgery are considered an important element of preanesthetic evaluation to determine the fitness for anesthesia and surgery. During past few decades this practice has been a subject of close scrutiny due to low yield and high aggregate cost. Performing routine screening tests in patients who are otherwise healthy is invariably of little value in detecting diseases and in changing the anesthetic management or outcome. Thorough history and investig...

  18. Laboratory investigation of enhanced oil recovery methods by chemical solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sayyouh, M.H.

    1982-01-01

    Results of an extensive laboratory study of the enhanced oil recovery methods, employing carbonated and caustic waterflooding, carbonated waterflooding with gas injection, polymer flooding, and surfactant-polymer flooding, are discussed. A series of the experiments were conducted in homogeneous and stratified sandpacks, while another series of runs were conducted in linear sandstone cores. Although caustic solutions markedly improved oil recovery, a higher recovery was obtained by using carbonated water, explained in terms of the dependence of oil recovery on pH of displacing water used. Using polymer solutions improved the mobility control of the displacement process. Polymer solutions were affected by thermal variations. The recovery ratio was increased with temperature. 25 references.

  19. Laboratory investigation for estimation of seismic response of the ground

    International Nuclear Information System (INIS)

    Laboratory measurements of soil properties can be used to supplement or confirm the results of field measurements. They are necessary to establish values of damping and modulus at strains larger than those that can be obtained in the field or to measure the properties of materials that do not exist in the field, such as soils to be compacted. The Dynamic Deformation Characteristics of the soil are used in order to calculate seismic response of ground, earth structures and structure-ground response. The improved cyclic triaxial equipment installed at CNRRS is used, when the dynamic properties of the soil must be obtained. In this test a cyclic load is applied to a column of soil over a number of cycles slowly enough that inertial effects do not occur. They are also used to express phenomenon that make soil to fail under seismic loading. Comparison of the obtained results with the well known international ones is presented. (authors)

  20. Experimental investigation of the Richtmyer-Meshkov instability.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Experimental investigations of silicon tetrafluoride decomposition in ECR discharge plasma.

    Science.gov (United States)

    Vodopyanov, A V; Golubev, S V; Mansfeld, D A; Sennikov, P G; Drozdov, Yu N

    2011-06-01

    The results of first experiments on the investigation of plasma of electron cyclotron resonance (ECR) discharge, sustained by CW radiation of technological gyrotron with frequency 24 GHz are considered. The parameters of nitrogen plasma of ECR discharge in magnetic field up to 1 T were investigated by Langmuir probe in the pressure range 10(-4)-10(-2) mbar under different values of microwave power. Depending on gas pressure and power of microwave radiation, the typical temperature and density of electrons could attain values of 1-5 eV and 10(11)-10(12) cm(-3), respectively. The prospects for using of ECR discharge for plasma chemical decomposition of silicon tetrafluoride (SiF(4)) have been experimentally demonstrated. Plasma was created from SiF(4) and hydrogen (H(2)) gas mixture and heated by microwave radiation in ECR conditions. Using the method of mass-spectrometry analysis of the gas at the outlet from the reactor and the weighting method, the content of the resultants of SiF(4) decomposition as a function of process parameters was investigated. It was shown that SiF(4) decomposition degree strongly depends on the microwave power, gas pressure in the reactor, gas flow rates, and can attain the value of 50%. The possible applications of PECVD method based on ECR discharge for production of isotopically pure elements with high deposition rate are discussed. PMID:21721687

  2. Experimental Investigation of Ice Phase Change Material Heat Exchangers

    Science.gov (United States)

    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.

  3. Experimental investigations in turbulent buoyant jets of sodium

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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

  5. Experimental investigation of bond strength under high loading rates

    Directory of Open Access Journals (Sweden)

    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.

  6. Experimental investigation of bond strength under high loading rates

    Science.gov (United States)

    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.

  7. Experimental Investigation of Turbulent Flow in Transition Duct

    Directory of Open Access Journals (Sweden)

    Hasan GÜL

    2012-12-01

    Full Text Available An experimental study was conducted to investigate turbulent flow through from rectangular cross-sectional area to rectangular transition duct. Three kinds of channels with different length, side angle and geometrical dimensions were designed and then flow characteristic of them were all tested. The transition duct have different inlet and outlet cross-sectional areas, outlet section is double than inlet sectional area. Measurements were made at several station along the channel and at various flow-rates, Reynolds numbers ranging from 2.105 to 6.105, in which the two–dimensional mean, local velocity and pressure were measured at the x/l = 0.20, 0.40, 0.60, 0.80, 1.00 ratio, inlet by using hot wire anemometer. Based on experimental results, different flow characteristics were obtained. According to mean and local velocity and pressure drop values, each section point of the transition duct showed various values. Friction coefficient was lowered with increasing pipe length and increasing Reynolds number. Cross flows was shown in the short pipe along length at the low Reynolds.

  8. Experimental Investigation on the Viscosity of Nano fluids

    International Nuclear Information System (INIS)

    In this study, the effect of adding SiO2 nanoparticles on the viscosity of base fluid is investigated experimentally. Base fluids are chosen among common heat transfer fluids such as ethylene glycol, transformer oil and water. In addition different volume percentages of ethylene glycol in water are used as ethylene glycol-water solution. In every base fluid different volume fractions of SiO2 nanoparticles is added. It is shown that the viscosity of solution enhance by adding nanoparticles. The effect of cooling and heating process on the viscosity of nano fluid is also discussed. The presented data show that as the temperature increases the viscosity of base fluid and nano fluid decrease. It is also revealed that there are very little differences between the viscosity of nano fluid in a specific temperature at cooling and heating cycles. According to the experimental results new correlations for predicting the viscosity of nano fluids is presented. These correlations relate the viscosity of nano fluid to the particle volume fraction and temperature.

  9. Experimental investigations of the functional morphology of dragonfly wings

    Science.gov (United States)

    Rajabi, H.; Darvizeh, A.

    2013-08-01

    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.

  10. Experimental investigation on the performance of a lithium chloride wheel

    Directory of Open Access Journals (Sweden)

    Rabah A.A.

    2012-01-01

    Full Text Available This work has investigated the influence of change in operation conditions on the performance of a Lithium Chloride (LiCl wheel. A rigorous experimental rig that facilitates the measurement of temperature, pressure, pressure drop, relative humidity, airflow rate and rotational speed is used. The measurements covered balanced flow at a wide range of rotational speeds (0 - 9.8 rpm, regeneration temperatures (50-70°C, airflow rates (280-540 kg/h and relative humidities (30-65% at ambient condition. The influence of those operation conditions on the wheel sensible effectiveness and coefficient of performance (COP are analyzed. The result revealed that a maximum COP occurs at a rotational speed of 0.2 rpm (12 rph. The results also concluded that Kays and London correlation is sufficient in the prediction of the effectiveness of the LiCl wheel. It represents the experimental data with an average absolute percent deviation (AAPD of 2.16 and a maximum absolute percent deviation (APDmax of about 6.00.

  11. Experimental investigation of a two-phase nozzle flow

    International Nuclear Information System (INIS)

    Stationary two-phase flow experiments with a convergent nozzle are performed. The experimental results are appropriate to validate advanced computer codes, which are applied to the blowdown-phase of a loss-of-coolant accident (LOCA). The steam-water experiments present a broad variety of initial conditions: the pressure varies between 2 and 13 MPa, the void fraction between 0 (subcooled) and about 80%, a great number of critical as well as subcritical experiments with different flow pattern is investigated. Additional air-water experiments serve for the separation of phase transition effects. The transient acceleration of the fluid in the LOCA-case is simulated by a local acceleration in the experiment. The layout of the nozzle and the applied measurement technique allow for a separate testing of blowdown-relevant, physical models and the determination of empirical model parameters, respectively. The measured quantities are essentially the mass flow rate, quality, axial pressure and temperature profiles as well as axial and radial density/void profiles obtained by a ?-ray absorption device. Moreover, impedance probes and a pitot probe are used. Observed phenomena like a flow contraction, radial pressure and void profiles as well as the appearance of two chocking locations are described, because their examination is rather instructive about the refinement of a program. The experimental facilities as well as the data of 36 characteristic experiments are documented. (orig.)

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

    International Nuclear Information System (INIS)

    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

  13. Experimental investigation into scaling models of methane hydrate reservoir

    International Nuclear Information System (INIS)

    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

  14. Experimental investigation and theoretical modelling of an impact damper

    Science.gov (United States)

    Vinayaravi, R.; Kumaresan, D.; Jayaraj, K.; Asraff, A. K.; Muthukumar, R.

    2013-03-01

    Impact damping is a method for improving damping of a dynamic system by means of energy dissipation due to repeated collisions of a free mass on the base structure. This paper deals with the theoretical and experimental investigations carried out to study and characterize damping with respect to the level of base excitation. The mathematical model consists of a two degree of freedom system (in which the main system is modelled as single degree of freedom system (sdof)) which undergoes momentum transfer between main mass and impact mass. The velocity response obtained from the mathematical model for the main mass and impact mass clearly indicates that the damping of the system depends on the number of effective impacts and not on the total number of impacts. Here the effect of impact damping is studied for low frequency and high amplitude excitation. Optimum parameters are determined for design of impact damper based on the mathematical model. Experiments are conducted on a cantilever beam for various excitation levels. The damping characteristics obtained from test data are compared with the predictions made from mathematical model. A good match is obtained between theoretical and experimental results. It is also observed that the energy gets re-distributed to higher modes due to the high shock that occurs during collision of the impact mass with main mass.

  15. Experimental investigation of synthetic aperture flow angle estimation

    DEFF Research Database (Denmark)

    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 for the experiments, and the emitted pulse is a 20 micro sec. chirp, linearly sweeping frequencies from approximately3.5 to 10.5 MHz. The flow angle could be estimated with an average bias up to 5.0 deg., and a average standard deviation between 0.2 deg. and 5.2 deg. Using the angle estimates, the velocity magnitudes were estimated with average standard deviations no higher than 6.5% relative to the peak velocity.

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

    Science.gov (United States)

    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.

  17. Experimental Investigation of Ternary Alloys for Fusion Breeding Blankets

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Experimental investigation on critical heat flux in vertical tubes

    International Nuclear Information System (INIS)

    An experimental study on critical heat flux of forced convection boiling in uniformly heated vertical tubes was performed in the KRISTA test facility at the Institute for Applied Thermo-and Fluid dynamics Karlsrule Research Center, using Freon-12 as the working fluid. Critical heat flux qc was measured in a 16 mm and a 2 mm diameter circular tubes. The effect of pressure, steam quality and mass velocity on CHF has been investigated. The results obtained were found to be essentially consistent in trend with the CHF data measured by other author. However, at lower pressure and mass velocity an anomalous phenomenon appeared: CHF decreased with decreasing inlet quality Xin in 2 mm diameter tube. The effect of pressure on CHF was complex. It was coupled with mass velocity and steam quality. At high mass velocity an inversion point was found out

  20. Experimental investigation of the backbending phenomenon in the Os region

    International Nuclear Information System (INIS)

    In the first part several models and theoretical formationa are discussed to explain the backbending effect. A short description of the apparatus for the measurements follows. Then the measurements on the even nuclei sup(182,184)Os and on the odd nuclei sup(181,183)Os and 181Re are discussed, which were investigated by in-beam spectroscopy. The rotational states of these nuclei were populated up to high spin states by the reactions 182W(?,5n)181Os, 186W(?,8n)182Os, 184W(?,5n)183Os, 186W(?,6n)184Os and 181Ta(?,4n)181Re. The ?-bombardement energies varied from 54 to 106. ?-single spectra, ?-?-coincidence spectra, angular distributions and time spectra were measured to get the energy levels of the rotational bands. The backbending curves which follow from these experimental results were discussed in the Rotation-Alignment model. (orig./WL)

  1. Experimental Investigation of Turbulence Specifications of Turbidity Currents

    Directory of Open Access Journals (Sweden)

    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.

  2. Experimental Investigation of MGB2 Switching with Magnetic Pulses

    Science.gov (United States)

    Ishmael, S. A.; Leveque, J.; Netter, D.; Meinke, R. B.; Masson, P. J.

    2010-04-01

    Superconducting machines require DC current excitation in the rotor usually achieved using brushless exciters relying on solid state components for current rectification. The use of solid state components limits the amount of current allowable and imposes a large inductance in the rotor. MgB2 allows for "close to" superconducting splicing enabling development of large current rotors where solid state devices could be advantageously replaced by superconducting switches and used with a flux pump excitation system. For certain applications, such as a synchronous condenser, the dynamics of the excitation system is important as well as imposing fast switching and fast recovery. Switches driven by magnetic pulses are expected to exhibit a very limited temperature increase leading to fast recovery and also to contribute to very good system dynamics. This paper covers the experimental investigation of the response of MgB2 conductors subjected to magnetic pulses. The dependence of the resistance vs. J/Jc and operating temperature are discussed.

  3. An experimental-differential investigation of cognitive complexity

    Directory of Open Access Journals (Sweden)

    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.

  4. Experimental and Theoretical Investigations of Charged Phospholipid Bilayers.

    Science.gov (United States)

    Graham, Ian Stanley

    1987-09-01

    Lipid systems containing charged species are examined by both experiment and theory. Experimental studies of the mixing of phosphatidylcholine or phosphatidylethanolamine with phosphatidic acid show that calcium induces fast ( <=q1s) phase separation of these otherwise miscible systems, and that this can occur in an isolated bilayer. Ionogenic behaviour is theoretically investigated using a new electrolyte model which explicitly includes both the solvent and particle sizes, and a binding model which uses Guggenheim combinatorics to treat non 1-1 binding stoichiometries. This work predicts a reduced dielectric constant near charged surfaces and strong repulsive forces between closely spaced (<15A) surfaces. A reanalysis of data from charged monolayers experiments indicates (1) that the new electrolyte model describes double layer behaviour at high surface charge densities better than the traditional Derjaguin - Landau - Verwey - Overbeek (DLVO) theory, (2) that calcium and magnesium bind to phosphatidylserine monolayers with a 1-1 stoichiometry.

  5. A review of experimental investigations on blast resistance of structures

    International Nuclear Information System (INIS)

    Investigations on blast resistance of structures received a lot of importance during and after the second world war. In recent years, this has assumed importance, in view of the rise in terrorist attack, accidents and sabotage. Development of computers and sophisticated instrumentation has led to more accurate mathematical modelling of the blast and response phenomena and more accurate validation of the mathematical model by experiments, bringing the analysis of this class of problems within the reach of the theoretical analyst. An attempt is made to review some recent trends in modelling, instrumentation and experimental procedures adopted by researchers working in the area of blast resistance of structures. (author). 32 refs., 8 figs., 1 tab

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Scientific Electronic Library Online (English)

    M., Fuentes; M. C., Mussati; P. A., Aguirre; N. J., Scenna.

    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 syste [...] m 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.

  8. Modeling and Laboratory Investigations of Evaporites on Mars

    Science.gov (United States)

    Bullock, M. A.; Moore, J. M.

    2009-12-01

    Evaporitic processes have been responsible for at least some of the sulfates and carbonates seen on the Martian surface (e.g. [Clark et al., 2005; McLennan et al., 2005; Squyres & Knoll, 2005]). Subsurface water charged with ions due to the dissolution of basalt and interaction with atmospheric CO2 and sulfur gases would have had the necessary chemistry to produce large quantities of evaporitic salts (e.g.[Bullock & Moore, 2004; Bullock et al., 2004; Tosca et al., 2005]). In the present work, we numerically modeled the formation of evaporites on Mars, using relevant laboratory work to constrain the calculations. Previously, we produced Mars-analog evaporites in the laboratory by desiccating brines formed under simulated Mars surface conditions [Moore et al., 2009]. The evaporites were created under two different conditions: Evaporation of brines at 3°C and 10 mbar of CO2, and evaporation of brines at 3°C and 10 mbar of CO2 with added acidic gases (100 ppm SO2, 10 ppm NO2, and 10 ppm HCl) to simulate an atmosphere rich in volcanic volatiles. We analyzed these evaporite products using IR spectroscopy and SEM microprobe. In general, Ca-sulfates dominated the precipitate mineralogy from the present-day Mars simulations, and for more acidic conditions, Mg-sulfates dominated, although both phases were observed in the precipitated products. In order to illuminate the actual formation processes of evaporites on Mars, we modeled the evaporation and the freezing/sublimation of brines under a wider range of conditions appropriate to Mars. Thermodynamic calculations using standard packages such as PHREEQ and Geochemist’s Workbench usually produce a large number of spurious species that are kinetically inhibited in natural settings. Therefore, using laboratory-derived results to realistically constrain precipitation products is essential for understanding the formation of evaporites on Mars. Our modeling results are quantitatively compared with the sulfates characterized at the Meridiani outcrops by MER Opportunity [Clark et al., 2005], just beneath the surface in the Columbia Hills by MER Spirit [Haskin et al., 2005], in the interior layered deposits of Valles Marineris [Bibring et al., 2005] and in the north polar dune fields by MEX OMEGA [Langevin et al., 2005]. Starting with brines at higher pH (6-8), we also compare model results with the carbonates seen in Nili Fossae by MRO CRISM [Ehlmann et al., 2008] and the CaCO3 seen by the Phoenix Lander [Boynton et al., 2009]. This work was supported by NASA MFRP grant NNX07AR68G to MAB, and a NASA PG&G grant to JMM. Bibring, J.-P., et al., Science 307, 1576-1581, 2005. Boynton, W. V., et al., Science 325, 61-64, 2009. Bullock, M. A., & J. M. Moore, GRL, 31, 2004 Bullock, M. A., et al., Icarus, 170, 404-423, 2004. Clark, B. C., et al., EPSL, 240, 73-94, 2005. Ehlmann, B. L., et al., Science, 322, 1828-1832, 2008. Haskin, L. A., et al., Nature, 436, 66-69, 2005. Langevin, Y., et al., Science, 307, 1584-1586, 2005. McLennan, et al., EPSL, 240, 95-121, 2005. Moore, J. M., et al., submitted to JGR, 2009. Squyres, S. W., & A. H. Knoll, EPSL, 240, 1-10, 2005. Tosca, N. J., et al., EPSL, 240, 122-148, 2005.

  9. Laboratory Investigation of Noise-Canceling Headphones Utilizing "Mr. Blockhead"

    Science.gov (United States)

    Koser, John

    2013-01-01

    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…

  10. Laboratory and Theoretical Investigations of a Ring-Capacitor Sensor

    Science.gov (United States)

    Ring-capacitor sensors are used widely for real-time estimation of volumetric soil water content ' from measured resonant frequency fr which is affected by the complex bulk soil permittivity ' = '’ + i'’’. However, the relationship fr(') requires improved investigation in terms of the dependence of ...

  11. Experimental investigations on airborne gravimetry based on compressed sensing.

    Science.gov (United States)

    Yang, Yapeng; Wu, Meiping; Wang, Jinling; Zhang, Kaidong; Cao, Juliang; Cai, Shaokun

    2014-01-01

    Gravity surveys are an important research topic in geophysics and geodynamics. This paper investigates a method for high accuracy large scale gravity anomaly data reconstruction. Based on the airborne gravimetry technology, a flight test was carried out in China with the strap-down airborne gravimeter (SGA-WZ) developed by the Laboratory of Inertial Technology of the National University of Defense Technology. Taking into account the sparsity of airborne gravimetry by the discrete Fourier transform (DFT), this paper proposes a method for gravity anomaly data reconstruction using the theory of compressed sensing (CS). The gravity anomaly data reconstruction is an ill-posed inverse problem, which can be transformed into a sparse optimization problem. This paper uses the zero-norm as the objective function and presents a greedy algorithm called Orthogonal Matching Pursuit (OMP) to solve the corresponding minimization problem. The test results have revealed that the compressed sampling rate is approximately 14%, the standard deviation of the reconstruction error by OMP is 0.03 mGal and the signal-to-noise ratio (SNR) is 56.48 dB. In contrast, the standard deviation of the reconstruction error by the existing nearest-interpolation method (NIPM) is 0.15 mGal and the SNR is 42.29 dB. These results have shown that the OMP algorithm can reconstruct the gravity anomaly data with higher accuracy and fewer measurements. PMID:24647125

  12. Experimental Investigations on Airborne Gravimetry Based on Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Yapeng Yang

    2014-03-01

    Full Text Available Gravity surveys are an important research topic in geophysics and geodynamics. This paper investigates a method for high accuracy large scale gravity anomaly data reconstruction. Based on the airborne gravimetry technology, a flight test was carried out in China with the strap-down airborne gravimeter (SGA-WZ developed by the Laboratory of Inertial Technology of the National University of Defense Technology. Taking into account the sparsity of airborne gravimetry by the discrete Fourier transform (DFT, this paper proposes a method for gravity anomaly data reconstruction using the theory of compressed sensing (CS. The gravity anomaly data reconstruction is an ill-posed inverse problem, which can be transformed into a sparse optimization problem. This paper uses the zero-norm as the objective function and presents a greedy algorithm called Orthogonal Matching Pursuit (OMP to solve the corresponding minimization problem. The test results have revealed that the compressed sampling rate is approximately 14%, the standard deviation of the reconstruction error by OMP is 0.03 mGal and the signal-to-noise ratio (SNR is 56.48 dB. In contrast, the standard deviation of the reconstruction error by the existing nearest-interpolation method (NIPM is 0.15 mGal and the SNR is 42.29 dB. These results have shown that the OMP algorithm can reconstruct the gravity anomaly data with higher accuracy and fewer measurements.

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

    International Nuclear Information System (INIS)

    In gas cloud explosions, turbulence is produced by the flow-field induced by the combustion process. But turbulence can also 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, inducing high pressure levels. The influence of an initial flow field must be taken into account, in connection with safety aspects of nuclear power plants. The reported laboratory-scale experiments were designed to investigate the influence of a flow field, present at the moment of ignition inside a partially-confined hydrocarbon-air cloud. These experiments used a flow channel capable of producing an unsteady flow-field of combustible gas independently of the combustion process itself. The parameters which varied in these tests are: initial flow velocity, gas-mixture composition and geometry. The tests were carried out with stochiometric ethylene-air and propane-air mixtures. The measured quantities are: pressure time history inside the test section. CH-radical radiation. High-speed photographs were also taken. The results show that initial flow speed and reactivity of the mixture have a strong influence on the maximum overpressure and duration of the positive pressure phase, but quenching effects may become important for high flow velocities and mixtures of low reactivity

  14. Experimental investigation of filtered epithermal-photoneutron Beams for BNCT

    International Nuclear Information System (INIS)

    The Idaho National Engineering Laboratory (INEL) has been investigating the feasibility of a concept for an accelerator-based source of epithermal neutrons for BNCT that is based on the use of a two-stage photoneutron production process driven by an electron accelerator. In this concept, relativistic electron beams impinge upon heavily-shielded tungsten targets located at the outer radius of a small cylindrical tank of circulating heavy water (D20). A fraction of the energy of the electrons is converted in the tungsten targets into radially-inward-directed bremsstrahlung radiation. Neutrons subsequently generated by photodisintegration of deuterons in the D2O within the tank are directed to the patient through a suitable beam tailoring system. Initial proof-of-principal tests using a low-current benchtop prototype of this concept have been conducted. Testing has included extensive measurements of the unfiltered photoneutron source as well as initial measurements of filtered epithermal-neutron spectra produced using two different advanced neutron filtering assemblies, as described here

  15. An Investigation into the Effectiveness of Problem-Based Learning in a Physical Chemistry Laboratory Course

    Science.gov (United States)

    Gurses, Ahmet; Acikyildiz, Metin; Dogar, Cetin; Sozbilir, Mustafa

    2007-01-01

    The aim of this study was to investigate the effectiveness of a problem-based learning (PBL) approach in a physical chemistry laboratory course. The parameters investigated were students' attitudes towards a chemistry laboratory course, scientific process skills of students and their academic achievement. The design of the study was one group…

  16. An Experimental Investigation on Inclined Negatively Buoyant Jets

    Directory of Open Access Journals (Sweden)

    Raed Bashitialshaaer

    2012-09-01

    Full Text Available 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 rate. Five geometric quantities describing the jet trajectory that are useful in the design of brine discharge systems were determined. Dimensional analysis demonstrated that the geometric jet quantities studied, if normalized with the jet exit diameter, could be related to the densimetric Froude number. Analysis of the collected data showed that this was the case for a Froude number less than 100, whereas for larger values of the Froude number the scatter in the data increased significantly. As has been observed in some previous investigations, the slope of the best-fit straight line through the data points was a function of the initial jet angle (?, where the slope increased with ? for the maximum levels (Ym studied, but had a more complex behavior for horizontal distances.

  17. Theoretical and experimental investigation of multispectral photoacoustic osteoporosis detection method

    Science.gov (United States)

    Steinberg, Idan; Hershkovich, Hadas Sara; Gannot, Israel; Eyal, Avishay

    2014-03-01

    Osteoporosis is a widespread disorder, which has a catastrophic impact on patients lives and overwhelming related to healthcare costs. Recently, we proposed a multispectral photoacoustic technique for early detection of osteoporosis. Such technique has great advantages over pure ultrasonic or optical methods as it allows the deduction of both bone functionality from the bone absorption spectrum and bone resistance to fracture from the characteristics of the ultrasound propagation. We demonstrated the propagation of multiple acoustic modes in animal bones in-vitro. To further investigate the effects of multiple wavelength excitations and of induced osteoporosis on the PA signal a multispectral photoacoustic system is presented. The experimental investigation is based on measuring the interference of multiple acoustic modes. The performance of the system is evaluated and a simple two mode theoretical model is fitted to the measured phase signals. The results show that such PA technique is accurate and repeatable. Then a multiple wavelength excitation is tested. It is shown that the PA response due to different excitation wavelengths revels that absorption by the different bone constitutes has a profound effect on the mode generation. The PA response is measured in single wavelength before and after induced osteoporosis. Results show that induced osteoporosis alters the measured amplitude and phase in a consistent manner which allows the detection of the onset of osteoporosis. These results suggest that a complete characterization of the bone over a region of both acoustic and optical frequencies might be used as a powerful tool for in-vivo bone evaluation.

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

    International Nuclear Information System (INIS)

    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

  19. Experimental Investigation of Organic Synthesis in Hydrothermal Environments

    Science.gov (United States)

    Shock, Everett L.

    1998-01-01

    The results of the investigation were presented at a Astrobiology Institute General Meeting. Seafloor hydrothermal systems may be the most likely locations on the early Earth for the emergence of life. Because of the disequilibrium inherent in such dynamic, mixing environments, abundant chemical energy would have been available for formation of the building blocks of life. In addition, theoretical studies suggest that organic compounds in these conditions would reach metastable states, due to kinetic barriers to the formation of stable equilibrium products (CO2 and methane). The speciation of organic carbon in metastable states is highly dependent on the oxidation state, pH, temperature, pressure and bulk composition of the system. The goal of our research is to investigate the effects of a number external variables on the formation, transformation, and stability of organic compounds at hydrothermal conditions. We have begun experimental work to attempt to control the oxidation state of simulated hydrothermal systems by using buffers composed of mineral powders and gas mixtures. We are also beginning to test the stability of organic compounds under these conditions.

  20. Experimental investigation of spray characteristics of alternative aviation fuels

    International Nuclear Information System (INIS)

    Highlights: • Physical properties of GTL fuel are different from those of conventional jet fuels. • Spray characteristics of GTL and Jet A-1 fuels are experimentally investigated using phase Doppler anemometry. • Regions near the nozzle are influenced by differences in fuel physical properties. • Spray characteristics of GTL can be predicted by empirical relations developed for conventional jet fuels. - Abstract: Synthetic fuels derived from non-oil feedstock are gaining importance due to their cleaner combustion characteristics. This work investigates spray characteristics of two Gas-to-Liquid (GTL) synthetic jet fuels from a pilot-scale pressure swirl nozzle and compares them with those of the conventional Jet A-1 fuel. The microscopic spray parameters are measured at 0.3 and 0.9 MPa injection pressures at several points in the spray using phase Doppler anemometry. The results show that the effect of fuel physical properties on the spray characteristics is predominantly evident in the regions close to the nozzle exit at the higher injection pressure. The lower viscosity and surface tension of GTL fuel seems to lead to faster disintegration and dispersion of the droplets when compared to those of Jet A-1 fuel under atmospheric conditions. Although the global characteristics of the fuels are similar, the effects of fuel properties are evident on the local spray characteristics at the higher injection pressure

  1. Using Experimental Methods to Investigate Discriminatory Tendencies: A Lesson Report

    Directory of Open Access Journals (Sweden)

    Yu-Wen Chen

    2013-08-01

    Full Text Available Using dictator games in experimental analysis, this lesson report demonstrates the process and results of a postgraduate class project in which university students were instructed to scientifically investigate and explore one of German society’s most hotly-contested issues: the level of discriminatory tendencies of non-Muslims towards Muslims. The results of this class project show little or no discriminatory tendencies toward Muslims. Instead, the university students under our investigation tended to act favorably, or at the very least, fairly toward Muslims. We expect that this lesson report can demonstrate how a postgraduate course can be conducted in an innovative way, empowering students to collect primary data and finishing a small scientific project during the span of a semester. Dieser Bericht stellt die Prozesse und Ergebnisse einer experimentellen Studie eines Postgraduierten-Kurses der Universität Greifswald dar. Wir zeigen, wie Studierende das Thema Migration innovativ untersuchen können, indem sie neben theoretischen Lerninhalten an experimentelle Methoden sowie die Primärforschung herangeführt werden. Anhand eines Diktatorspiels wurden die teilnehmenden Studenten angeleitet, ein in der Öffentlichkeit kontrovers debattiertes Thema wissenschaftlich zu untersuchen: Diskriminierende Tendenzen von Nicht-Muslimen gegenüber Muslimen. Die Ergebnisse dieser Studie lassen jedoch nicht auf diskriminierende Tendenzen der Studenten schließen. Stattdessen deuten sie darauf hin, dass sich die Studierenden zumindest fair gegenüber Muslimen verhalten.

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

    Science.gov (United States)

    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.

  3. Laboratory investigations of the survivability of bacteria in hypervelocity impacts.

    Science.gov (United States)

    Burchell, M J; Shrine, N R; Mann, J; Bunch, A W; Brandao, P; Zarnecki, J C; Galloway, J A

    2001-01-01

    It is now well established that material naturally moves around the Solar System, even from planetary surface to planetary surface. Accordingly, the idea that life is distributed throughout space and did not necessarily originate on the Earth but migrated here from elsewhere (Panspermia) is increasingly deemed worthy of consideration. If life arrived at the Earth from space, its relative speed will typically be of order many km s-1, and the resulting collision with the Earth and its atmosphere will be in the hypervelocity regime. A mechanism for the bacteria to survive such an impact is required. Therefore a programme of hypervelocity impacts in the laboratory at (4.5 +/- 0.6) km s-1 was carried out using bacteria (Rhodococcus) laden projectiles. After impacts on a variety of target materials (rock, glass and metal) attempts were made to culture Rhodococcus from the surface of the resulting craters and also from the target material ejected during crater formation. Control shots with clean projectiles yielded no evidence for Rhodococcus growth from any crater surface or ejecta. When projectiles doped with Rhodococcus were used no impact crater surface yielded colonies of Rhodococcus. However, for four shots of bacteria into rock (two on chalk and two on granite) the ejecta was afterwards found to give colonies of Rhodococcus. This was not true for shots onto glass. In addition, shots into aerogel (density 96 kg m-3) were also carried out (two with clean projectiles and two with projectiles with Rhodococcus). This crudely simulated aero-capture in a planetary atmosphere. No evidence for Rhodococcus growth was found from the projectiles captured in the aerogel from any of the four shots. PMID:11803976

  4. Investigating tension in the laboratory: Implications for volcanic processes

    Science.gov (United States)

    Wall, Richard; Lavallée, Yan; Kendrick, Jackie; Iddon, Fiona; Hornby, Adrian; Lamur, Anthony; von Aulock, Felix; Wadsworth, Fabian; Kilburn, Christopher; Browning, John; Meredith, Philip

    2015-04-01

    Tensile fracturing is an important process that occurs at divergent plate boundaries and can also be observed at convergent plate boundaries, where it accommodates compression. Owing to the difficulty of simulating tensile loading in the laboratory very few data exist on how rock fails in this mode and how this process changes with temperature and strain rate. To address this issue we present the results from a range of experiments that examine direct tension under controlled conditions. Experiments have been undertaken using basalt from the base of Eyjafjallajökull volcano and use a novel methodology of inducing tension through cooling. Initially, samples are heated above their solidus temperature and are allowed to expand within the apparatus. The samples are then locked in place and cooled at rates between 0.1 and 10 ° C.min-1, inducing tension within the sample. We compare results from these direct tension test with indirect tension Brazilian tests, using the same rock type, at different temperatures (between room temperature and 900° C) and at a compaction rate of 4 x 10-4 mm.s-1. From Brazilian tests the tensile strengths of samples are between 10 and 20 MPa, with an overall increase in strength with increasing temperature. Cooling induced tension experiments show that direct tensile strength is commonly 50 to 75 % of the strength under indirect tension conditions and that an increase in cooling rate generally decreases the strength of the samples. These experiments show a complex stress history during cooling, from the onset to completion of fracturing. Complementary experiments have also been undertaken on Seljadur basalt from Iceland, where acoustic emissions and seismic velocities indicate that the magnitude of thermal cracking is greater during cooling than heating. These initial results have significant implications for understanding the conditions required for tensile failure in the field and the controls on the formation of the resulting fracture.

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

    International Nuclear Information System (INIS)

    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)

  6. Laboratory Investigation of Entrainment and Mixing in Oceanic Overflows

    CERN Document Server

    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...

  7. A review of geophysical investigations at the site of Chalk River Nuclear Laboratories, Ontario

    International Nuclear Information System (INIS)

    The site of the Chalk River Nuclear Laboratories was one of the first research areas located on crystalline rocks to be extensively investigated under the Canadian Nuclear Fuel Waste Management Program. A large contribution to meeting the geoscientific objectives of the program has been made using a suite of geophysical techniques. Many of them are standard, though sometimes modified in terms of instrumentation and/or experimental and/or analytical procedures, to meet the particular needs of the waste management program. Relatively new techniques have also been employed. Much of the early evaluation and development of the various techniques took place at the Chalk River site. Standard methods such as gravity, magnetics and seismic sounding have been used to investigate bedrock structure, and the seismic method has also been used to estimate overburden thickness. Standard geophysical borehole logging has been used to obtain in situ estimates of physical properties, to locate fracture zones and to make hole to hole correlations that have helped define local structure. Several standard electrical (e.g. resitivity) and electromagnetic (e.g. VLF-EM) techniques have proven successful in identifying water-filled fractures and faults. Relatively new techniques introduced into the geophysics at Chalk River were: ground probing radar; to investigate overburden; borehole TV and acoustic televiewer and VLF-EM, to locate fractures; studies of seismic tube-waves, well tides and temperature logs, to investigate fracture location and permeability. Most of these methods have been successful and are now routinely employed at other research sites

  8. Site characterization investigations at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    The geologic and geohydrologic characterization and assessment techniques currently used at ORNL are integrated into a systematic approach. The investigations are multi-faceted, and involve investigators with a variety of expertise. Characterization studies are designed to obtain the data requirements of pathways analysis and facility design in addition to the detailed site description. The approach effectively minimizes the redundancy and lack of coordination which often arise when the study is broken down into totally independent tasks. The geologic environment of the Oak Ridge Reservation is one of structural and stratigraphic complexity which requires a comprehensive and systematic approach to characterize. Recent characterization studies have included state-of-the-science techniques in the areas of unsaturated zone testing, geochemical tests to determine attenuation properties of soils, and numerical analyses of site performance. The results of these studies and analyses are changing the technology of shallow land burial by indicating that chemically stable waste forms are required to limit radionuclide migration to acceptable levels. 11 refs., 1 tab

  9. Experimental investigation on compaction properties of sandy soils

    International Nuclear Information System (INIS)

    In this research, an effort has been made to develop a correlation between standard and modified proctor compaction test parameters, i.e., maximum dry unit weight (gamma dmax) and optimum moisture content (OMC) of sandy soils. Standard and modified proctor along with classification tests were carried out on hundred and twenty sandy soil samples with different grain size distributions. Based on the test results, the soil samples were classified into various groups of medium to fine sand with non-plastic fines up to 45%. Regression analyses were performed on the experimental data and correlations were proposed to express modified Proctor parameters (gamma dmod and OMC mod) in term of standard Proctor test parameters (gamma dstd and OMC std). The validation of the proposed predictive correlations was done by using test results of another set of sandy soil samples not used in the development of the correlations. The results of the analyses showed that variation between experimental and predicted values of gamma dmod is within +- 4 % confidence interval and that of OMC mod is within +- 2.0 %. Further, based on the test results, an effort has been made to investigate the effect of fines (finer than 75 mu m) on compaction characteristics. It was observed that gamma dmax both in case of standard and modified proctor increases with increase in fines content up to 35% and beyond that it decreases. However, the value of OMC in both the cases decreases with increase in fine content. The correlations proposed in this paper may be very useful during the project preliminary/ pre-feasibility stages in the field of Geotechnical Engineering. (author)

  10. Calculation and experimental investigation of multi-component ceramic systems

    International Nuclear Information System (INIS)

    This work shows a way to combine thermodynamic calculations and experiments in order to get useful information on the constitution of metal/non-metal systems. Many data from literature are critically evaluated and used as a basis for experiments and calculations. The following multi-component systems are treated: 1. Multi-component systems of 'ceramic' materials with partially metallic bonding (carbides, nitrides, oxides, borides, carbonitrides, borocarbides, oxinitrides of the 4-8th transition group metals) 2. multi-component systems of non-metallic materials with dominant covalent bonding (SiC, Si3N4, SiB6, BN, Al4C3, Be2C) 3. multi-component systems of non-metallic materials with dominant heteropolar bonding (Al2O3, TiO2, BeO, SiO2, ZrO2). The interactions between 1. and 2., 2. and 3., 1. and 3. are also considered. The latest commercially available programmes for the calculation of thermodynamical equilibria and phase diagrams are evaluated and compared considering their facilities and limits. New phase diagrams are presented for many presently unknown multi-component systems; partly known systems are completed on the basis of selected thermodynamic data. The calculations are verified by experimental investigations (metallurgical and powder technology methods). Altogether 690 systems are evaluated, 126 are calculated for the first time and 52 systems are experimentally verified. New data for 60 ternary phases are elaborated by estimating the data limits for the Gibbs energy values. A synthesis of critical evaluation of literature, calculations and experiments leads to new important information about equilibria and reaction behaviour in multi-component systems. This information is necessary to develop new stable and metastable materials. (orig./MM)

  11. Pain-avoidance versus reward-seeking: an experimental investigation.

    Science.gov (United States)

    Claes, Nathalie; Crombez, Geert; Vlaeyen, Johan W S

    2015-08-01

    According to fear-avoidance models, a catastrophic interpretation of a painful experience may give rise to pain-related fear and avoidance, leading to the development and maintenance of chronic pain problems in the long term. However, little is known about how exactly motivation and goal prioritization play a role in the development of pain-related fear. This study investigates these processes in healthy volunteers using an experimental context with multiple, competing goals. In a differential human fear-conditioning paradigm, 57 participants performed joystick movements. In the control condition, one movement (conditioned stimulus; CS) was followed by a painful electrocutaneous unconditioned stimulus (pain-US) in 50% of the trials, whereas another movement (nonreinforced conditioned stimulus; CS) was not. In the experimental condition, a reward in the form of lottery tickets (reward-US) accompanied the presentation of the pain-US. Participants were classified into 3 groups, as a function of the goal, they reported to be the most important: (1) pain-avoidance, (2) reward-seeking, and (3) both goals being equally important. Results indicated that neither the reward co-occurring with pain nor the prioritized goal modulated pain-related fear. However, during subsequent choice trials, participants selected the painful movement more often when the reward was presented compared with the context in which the reward was absent. The latter effect was dependent on goal prioritization, with more frequent selections in the reward-seeking group, and the least selections in the pain-avoidance group. Taken together, these results underscore the importance of competing goals and goal prioritization in the attenuation of avoidance behavior. PMID:25775360

  12. Theoretical and experimental investigation of cappillary electrolysis system

    International Nuclear Information System (INIS)

    In a fusion reactor environment, it is expected that highly tritiated water will be formed when tritium is extracted from the blanket as well as during the plasma exhaust purification process. As a consequence, the recovery of elemental tritium from its oxides is an essentrial step before recycling the fuel to the reactor. Among different basic processes that can be used for this purpose, electrolysis appears to be very promising. Therefore, SCK/CEN has developed a small dedicated cell designed to decompose 100 ml/day of pure DTO or HTO. At the present project stage, a prototype cell is available and the device has been successfully tested with light water during several thousands of hours. In the orginal concept, the liquid inventory is limited to the vertical porous gas separator. Capillarity is used as a driving force to feed the cell to avoid the use of a pump. This fact turns out to have a considerable influence on the behaviour of the electrolytic system. This particular behaviour has been theorectically investigated with the aim to allow a better basic understanding of the capillary electrolysis. A deterministic model has been developed for its purpose. The mathematical equations show clearly that the electrolyte tends to accumulate at the top of the gas separator. An equilibrium state can be reached only if sufficiently large amounts of electrolyte can flow back towards the bottom of the gas separator. This counter-flow has been taken into account by introducing a single general diffusion coefficient into the model. In a second phase, systematic experimental runs have been carried out with mock-up cells. A statistical treatment based on the maximum likelihood estimation algorithm allowed to compute the best values for the diffusion coefficient and to validate the model. Finally, acceptabel ranges of the independent varialbles have been defined and all the subsequent experimental runs have been performed without stability problems. (author). 12 refs.; 5 figs.; 1 tab

  13. Experimental Investigation of Piston Rings for Internal Combustion Engines

    DEFF Research Database (Denmark)

    Klit, Peder; VØlund, Anders

    2008-01-01

    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 load may be established by measuring the pressure distribution, i.e. the pressure drop in the piston ring package. Speed and temperature may also be established. The amount and distribution of oil present is, however, not easily determined. It is often assumed that it operates under fully flooded 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 absorbed in the bearing. Since the frictional forces are small compared to the rest of the acting forces the rig is designed such that the piston is fixed while the cylinder liner moves. This approach makes it simple to measure the parameters mentioned above by putting the instrumentation in the piston 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 significant. Experimental results are presented and the influence from speed, number of piston rings, lubrication oil type and supply oil is discussed.

  14. REVIEW OF EXPERIMENTAL STUDIES INVESTIGATING THE RATE OF STRONTIUM AND ACTINIDE ADSORPTION BY MONOSODIUM TITANATE

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.

    2010-10-01

    A number of laboratory studies have been conducted to determine the influence of mixing and mixing intensity, solution ionic strength, initial sorbate concentrations, temperature, and monosodium titanate (MST) concentration on the rates of sorbate removal by MST in high-level nuclear waste solutions. Of these parameters, initial sorbate concentrations, ionic strength, and MST concentration have the greater impact on sorbate removal rates. The lack of a significant influence of mixing and mixing intensity on sorbate removal rates indicates that bulk solution transport is not the rate controlling step in the removal of strontium and actinides over the range of conditions and laboratory-scales investigated. However, bulk solution transport may be a significant parameter upon use of MST in a 1.3 million-gallon waste tank such as that planned for the Small Column Ion Exchange (SCIX) program. Thus, Savannah River National Laboratory (SRNL) recommends completing the experiments in progress to determine if mixing intensity influences sorption rates under conditions appropriate for this program. Adsorption models have been developed from these experimental studies that allow prediction of strontium (Sr), plutonium (Pu), neptunium (Np) and uranium (U) concentrations as a function of contact time with MST. Fairly good agreement has been observed between the predicted and measured sorbate concentrations in the laboratory-scale experiments.

  15. Experimental investigation of hydraulic criteria in the fishways

    International Nuclear Information System (INIS)

    Migratory Fish travel downstream to reach larger body of water where the food is available. When they grows, migrate upstream to the place of their birth to spawn. In areas where fish have a commercial value and to keep alive these species as a part of environment, care must be done not to stop such migration specially by constructing the dams across the rivers. Diversion dams usually built across the river to divert some portion of the river flow for irrigation lands. In such dams, the engineers must provide a passage called 'FISHWAY'; for fish in order that fish can travel from down stream to the upstream of the dam. Of course, if such structure is not considered, the fish can not travel upstream to spawn, therefore in the long term these species will diminish. In this study a hydraulic model was conducted to investigate the hydraulic conditions of a vertical-slot type of fishway which has been considered for Ramhormoz diversion dam in the province of Khouzestan, Iran. The Froudian hydraulic model with the scale of 1:5 was constructed at the hydraulic laboratory of Shahid Chamran University. Tests were performed for the original design and two other alternatives slot-opening angles. Another fishway called Denil, also was tested. From the observation and data obtained from these tests, it was found that 90-degree slot opening provide suitable hydraulic conditions. Denil fishway also was found to satisfy the hydraulic criteria and due its simplicity and rapid construction was recommended to be used in this diversion dam. (author)

  16. Experimental investigation of an indirect type natural convection solar dryer

    Energy Technology Data Exchange (ETDEWEB)

    El-Sebaii, A.A.; Aboul-Enein, S.; Ramadan, M.R.I.; El-Gohary, H.G. [Tanta Univ. (Egypt). Dept. of Physics

    2002-11-01

    An indirect type natural convection solar dryer is designed, constructed and investigated experimentally under Tanta prevailing weather conditions. The system consists of a flat plate solar air heater connected to a cabinet acting as a drying chamber. The air heater is designed to be able to insert various storage materials under the absorber plate in order to improve the drying process. Sand is used as the storage material. Drying experiments have been conducted with and without storage materials for different spherical fruits, such as seedless grapes, figs and apples, as well as vegetables, such as green peas, tomatoes and onions. The solar irradiance, temperature distribution in different parts of the system, ambient temperature and relative humidity of the inlet and outlet drying air have been recorded. The equilibrium moisture content M{sub e} for seedless grapes is reached after 60 and 72 h when the system is used with and without storage material, respectively. Therefore, the storage material reduces the drying process by 12 h. In order to accelerate the drying process, the drying products are divided into pieces and then chemically treated by dipping the samples into boiling water containing 0.4% olive oil and 0.3% NaOH for 60 s. However, the required time to achieve M{sub e} for the chemically treated seedless grapes, when the system is used with sand as a storage material, is drastically reduced to 8 h. Moreover, we found that the storage and chemical pretreatment have caused significant decreases of the drying time for all the investigated crops. The present system is capable of drying 10 kg of chemically treated grapes or green peas during 20 h of sunshine. (author)

  17. LABORATORY INVESTIGATIONS OF SILICATE MUD CONTAMINATION WITH CALCIUM

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Me?imurec

    2004-12-01

    Full Text Available The silicate-based drilling fluid is a low solids KCl/polymer system with the addition of soluble sodium or potassium silicate to enhance inhibition and wellbore stability. Silicate-based drilling fluids exhibit remarkable shale and chalk stabilizing properties, resulting in gauge hole and the formation of firm cuttings when drilling reactive shales and soft chalks. Silicates protect shales by in-situ gellation when exposed to the neutral pore fluid and precipitation, which occurs on contact with divalent ions present at the surface of the shale. Also, silicates prevent the dispersion and washouts when drilling soft chalk by reacting with the Ca2+ ions present on chalk surfaces of cutting and wellbore to form a protective film. The silicate-based drilling fluid can be used during drilling hole section through shale interbeded anhydrite formations because of its superior shale stabilizing characteristics. However, drilling through the anhydrite can decrease the silicate concentration and change rheological and filtration fluid properties. So, the critical concentration of calcium ions should be investigated by lab tests. This paper details the mechanism of shale inhibition using silicate-based drilling fluid, and presents results of lab tests conducted to ascertain the effect of Ca2+ ions on silicate level in the fluid and the fluid properties.

  18. Site Safety Plan for Lawrence Livermore National Laboratory CERCLA investigations

    Energy Technology Data Exchange (ETDEWEB)

    Bainer, R.; Duarte, J.

    1993-07-01

    The safety policy of LLNL is to take every reasonable precaution in the performance of work to protect the environment and the health and safety of employees and the public, and to prevent property damage. With respect to hazardous agents, this protection is provided by limiting human exposures, releases to the environment, and contamination of property to levels that are as low as reasonably achievable (ALARA). It is the intent of this Plan to supply the broad outline for completing environmental investigations within ALARA guidelines. It may not be possible to determine actual working conditions in advance of the work; therefore, planning must allow the opportunity to provide a range of protection based upon actual working conditions. Requirements will be the least restrictive possible for a given set of circumstances, such that work can be completed in an efficient and timely fashion. Due to the relatively large size of the LLNL Site and the different types of activities underway, site-specific Operational Safety Procedures (OSPs) will be prepared to supplement activities not covered by this Plan. These site-specific OSPs provide the detailed information for each specific activity and act as an addendum to this Plan, which provides the general plan for LLNL Main Site operation.

  19. Laboratory and Theoretical Investigations on Mechanical Behavior of PLFG Mixture

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2013-01-01

    Full Text Available Phosphogypsum-lime-flyash-gravel Mixture (PLFG is usually used to strengthen road foundation of geotechnical engineering. It is important to correctly understand its mechanical behavior before corresponding design. In this present paper, compaction test, one-dimensional compression test and dry-shrinkage test were conducted to determine optimum mixture ration of PLFG. compression test on PLFG with optimum ration was carried out in order to investigate its stress-strain curve. Experiment data show that PLFG is with high bearing capacity and good stiffness. A new composite-exponent model was established, which is available for both hardening and softening type strain-stress curves of PLFG. Mathematical behavior of the presented model is far better than others to describe PLFG’s structural property. Finally, comparison between PLFG tested data and new model simulation was performed and good agreements have been found. This research is helpful for engineering sustainable utilization of to bring economy and to reduce environmental pollution.

  20. An experimental investigation of pump as turbine for micro hydro application

    International Nuclear Information System (INIS)

    This paper presents the results of an experimental investigation of a centrifugal pump working as turbine (PAT). An end suction centrifugal pump was tested in turbine mode at PAT experimental rig installed in the Mechanical Engineering Laboratory of Universiti Tenaga Nasional. The pump with specific speed of 15.36 (m, m3/s) was used in the experiment and the performance characteristic of the PAT was determined. The experiment showed that a centrifugal pump can satisfactorily be operated as turbine without any mechanical problems. As compared to pump operation, the pump was found to operate at higher heads and discharge values in turbine mode. The best efficiency point (BEP) in turbine mode was found to be lower than BEP in pump mode. The results obtained were also compared to the work of some previous researchers.

  1. Laboratory investigation of wind wave breaking modulation in the inhomogeneous current field

    Science.gov (United States)

    Bakhanov, Victor; Bogatov, Nikolai; Ermoshkin, Alexei; Kemarskaya, Olga

    2015-10-01

    A experimental laboratory study of the effect of a horizontally inhomogeneous current on breaking statistics of wind waves was carried out. Were creating a current having the same direction as wind waves with positive and negative gradients and a current of the counter direction with a negative gradient. The wind speed varied from 10.4 to 20.1 m/s based on a standard height of 10 m. The maximum current velocity near the surface was 27 cm/s. The maximum current gradient was equal to 0.09 1/s. The codirected current reduces the wind wave amplitude for all wind speeds, while the frequency of the spectral density maximum of wind waves remains the same. The frequency of the recorded by radar wind-wave breaking also decreases for positive, negative, and zero gradients. In the case of counter directions, for light winds in the presence of a current the wind wave amplitude reduces, the wind wave spectrum displaces in the direction of lower frequencies. At higher wind speeds, there were neither differences in the surface wave spectra in the presence and absence of a current, however, an increase in the frequency of the recorded by radar wind-wave breaking is observed. These laboratory investigations are carried out in the interests of the remote diagnostics methods development of inhomogeneous currents at higher wind speeds.

  2. HESS Opinions On the use of laboratory experimentation: "Hydrologists, bring out shovels and garden hoses and hit the dirt"

    Directory of Open Access Journals (Sweden)

    M. van der Perk

    2010-02-01

    Full Text Available From an outsider's perspective, hydrology combines field work with modelling, but mostly ignores the potential for gaining understanding and conceiving new hypotheses from controlled laboratory experiments. Sivapalan (2009 pleaded for a question- and hypothesis-driven hydrology where data analysis and top-down modelling approaches lead to general explanations and understanding of general trends and patterns. We discuss why and how such understanding is gained very effectively from controlled experimentation in comparison to field work and modelling. We argue that many major issues in hydrology are open to experimental investigations. Though experiments may have scale problems, these are of similar gravity as the well-known problems of fieldwork and modelling and have not impeded spectacular progress through experimentation in other geosciences.

  3. Experimental investigation and mechanistic modelling of dilute bubbly bulk boiling

    International Nuclear Information System (INIS)

    During evaporation the geometric shape of the vapour is not described using thermodynamics. In bubbly flows the bubble shape is considered spheric with small diameters and changing into various shapes upon growth. The heat and mass transfer happens at the interfacial area. The forces acting on the bubbles depend on the bubble diameter and shape. In this work the prediction of the bubble diameter and/or bubble number density in bulk boiling was considered outside the vicinity of the heat input area. Thus the boiling effects that happened inside the nearly saturated bulk were under investigation. This situation is relevant for nuclear safety analysis concerning a stagnant coolant in the spent fuel pool. In this research project a new experimental set-up to investigate was built. The experimental set-up consists of an instrumented, partly transparent, high and slender boiling container for visual observation. The direct visual observation of the boiling phenomena is necessary for the identification of basic mechanisms, which should be incorporated in the simulation model. The boiling process has been recorded by means of video images and subsequently was evaluated by digital image processing methods, and by that data concerning the characteristics of the boiling process were generated for the model development and validation. Mechanistic modelling is based on the derivation of relevant mechanisms concluded from observation, which is in line with physical knowledge. In this context two mechanisms were identified; the growth/-shrink mechanism (GSM) of the vapour bubbles and sudden increases of the bubble number density. The GSM was implemented into the CFD-Code ANSYS-CFX using the CFX Expression Language (CEL) by calculation of the internal bubble pressure using the Young-Laplace-Equation. This way a hysteresis is realised as smaller bubbles have an increased internal pressure. The sudden increases of the bubble number density are explainable by liquid super-heating. The liquid super-heating is only possible if the heat and mass transfer between the phases is slower than the saturation temperature reduction by hydrostatic pressure decreases along the height of the boiling container or due to bubble growth. By activation of the so far inactive micro-bubbles in the liquid bulk volume the bubble number density quickly increases. This effect is modelled by an algebraic function that uses a constant bubble number density in the vicinity of the saturation temperature and applies an exponentially increased bubble number density depending on the liquid super-heating. Based on modelling a local and variable bubble number density numerical flow simulations were performed. The simulations showed that this approach is a suitable model to describe the mechanisms found in the experiments. Model parameters were determined and verified by correlation with the experimental data.

  4. Numerical and experimental investigations on unsteady aerodynamics of flapping wings

    Science.gov (United States)

    Yu, Meilin

    The development of a dynamic unstructured grid high-order accurate spectral difference (SD) method for the three dimensional compressible Navier-Stokes (N-S) equations and its applications in flapping-wing aerodynamics are carried out in this work. Grid deformation is achieved via an algebraic blending strategy to save computational cost. The Geometric Conservation Law (GCL) is imposed to ensure that grid deformation will not contaminate the flow physics. A low Mach number preconditioning procedure is conducted in the developed solver to handle the bio-inspired flow. The capability of the low Mach number preconditioned SD solver is demonstrated by a series of two dimensional (2D) and three dimensional (3D) simulations of the unsteady vortex dominated flow. Several topics in the flapping wing aerodynamics are numerically and experimentally investigated in this work. These topics cover some of the cutting-edge issues in flapping wing aerodynamics, including the wake structure analysis, airfoil thickness and kinematics effects on the aerodynamic performances, vortex structure analysis around 3D flapping wings and the kinematics optimization. Wake structures behind a sinusoidally pitching NACA0012 airfoil are studied with both experimental and numerical approaches. The experiments are carried out with Particle Image Velocimetry (PIV) and two types of wake transition processes, namely the transition from a drag-indicative wake to a thrust-indicative wake and that from the symmetric wake to the asymmetric wake are distinguished. The numerical results from the developed SD solver agree well with the experimental results. It is numerically found that the deflective direction of the asymmetric wake is determined by the initial conditions, e.g. initial phase angle. As most insects use thin wings (i. e., wing thickness is only a few percent of the chord length) in flapping flight, the effects of airfoil thickness on thrust generation are numerically investigated by simulating the flow fields around a series of plunging NACA symmetric airfoils with thickness ratio ranging from 4.0% to 20.0% of the airfoil chord length. The contribution of viscous force to flapping propulsion is accessed and it is found that viscous force becomes thrust producing, instead of drag producing, and plays a non-negligible role in thrust generation for thin airfoils. This is closely related to the variations of the dynamics of the unsteady vortex structures around the plunging airfoils. As nature flyers use complex wing kinematics in flapping flight, kinematics effects on the aerodynamic performance with different airfoil thicknesses are numerically studied by using a series of NACA symmetric airfoils. It is found that the combined plunging and pitching motion can outperform the pure plunging or pitching motion by sophisticatedly adjusting the airfoil gestures during the oscillation stroke. The thin airfoil better manipulates leading edge vortices (LEVs) than the thick airfoil (NACA0030) does in studied cases, and there exists an optimal thickness for large thrust generation with reasonable propulsive efficiency. With the present kinematics and dynamic parameters, relatively low reduced frequency is conducive for thrust production and propulsive efficiency for all tested airfoil thicknesses. In order to obtain the optimal kinematics parameters of flapping flight, a kinematics optimization is then performed. A gradient-based optimization algorithm is coupled with a second-order SD Navier-Stokes solver to search for the optimal kinematics of a certain airfoil undergoing a combined plunging and pitching motion. Then a high-order SD scheme is used to verify the optimization results and reveal the detailed vortex structures associated with the optimal kinematics of the flapping flight. It is found that for the case with maximum propulsive efficiency, there exists no leading edge separation during most of the oscillation cycle. In order to provide constructive suggestions to the design of micro-air-vehicles (MAVs), 3D simulations of the flapping wings are carrie

  5. Experimental investigations of the ''Angara-5'' facility module

    International Nuclear Information System (INIS)

    The description and results of experimental investigation of the head module of the ''Angara-5'' facility are presented. The module represents and energy storage consisting of the Arkadiev-Marx generator and double shaping line (DSL). The intermediate DSL electrode is conneeted with the generator by two conductors passing through the separating section with four dielectric partitions. In the course of DSL commutation realized by five gass-filled commutators internal electrode charging is performed through the cantilever being isolation induction. Basic DSL characteristics are given. In the process of operation on increasing charge module voltage about 180 pulses with DSL charge voltage-1 MV, 80 pulses with charge voltage 1,6 MV and 10 pulses with 2,1 MV voltage have been performed. In all module operation conditions no break-down in water have been observed. Time spread of commutators switch on not exceeding +- 2,6 ns. Gas discharge channel losses are given. The module power balance under capacitor charging voltage +- 80 kV is presented

  6. Numerical and experimental investigation of thermosyphon solar water heater

    International Nuclear Information System (INIS)

    Highlights: • We studied a thermosyphon solar water heater composed of high-performance components. • A differential equations solution technique is investigated. • The influences of the collector and storage losses on the system performance were examined. • The storage losses have more influence on the long-term performance. - Abstract: A glassed flat plate collector with selective black chrome coated absorber and a low wall conductance horizontal storage are combined in order to set up a high performance thermosyphon system. Each component is tested separately before testing the complete system in spring days. During the test period, effect of different inlet water temperatures on the collector performance is studied and results have shown that the collector can reach a high efficiency and high outlet water temperature even for elevated inlet water temperatures. Subsequently, long term system performance is estimated by using a developed numerical model. The proposed model, accurate and gave a good agreement with experimental results, allowed to describe the heat transfer in the storage. It has shown also that the long-term performances are strongly influenced by losses from the storage than losses from the collector

  7. Experimental investigation on laser removal of carbon and tungsten particles

    International Nuclear Information System (INIS)

    During the operation of the ITER fusion facility, particles with size from 10 nm to 100 ?m, mainly composed of carbon, beryllium, and tungsten, will be produced. Since dust could lead to safety issues, it must be periodically removed from the facility in order to keep their quantity below the safety limit requirements. In this context, laser cleaning appeared as a very promising technique, and investigations have to be done to understand the physical processes and optimize the procedure. Several experiments were carried out to improve the understanding of the phenomena involved during the laser-induced removal of Carbon particles. The ejection mechanisms have been experimentally studied for different irradiation conditions with nanosecond laser pulses. The removal efficiency and the fluence threshold were determined by optical microscopy. The influence of the substrate was studied for the dry laser cleaning configuration. This study presents scanning electronic microscopy pictures which show that the particle removal leads to a damage of the substrate. These damages give evidences on the ablation mechanism. The laser shock cleaning was also studied. In this configuration, the laser-induced shock wave can be used to push the particles away from the surface. This technique appears to be very useful to clean shadowed areas

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

    Directory of Open Access Journals (Sweden)

    SUBRAMANYAM PAVULURI, DR. A. SIVA KUMAR

    2013-05-01

    Full Text Available 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 the environmental and economical impact of any coal-fired power station. To increasing the efficiency of a typical 500MW turbine by 1% reduces emissions of CO2 from the turbine station, with corresponding reductions in NOx and SOx. In this connection an attempt is made on steam turbine blade performance is important criterion for retrofit coal fired power plant. Based on the research presented modifications to high pressure high pressure steam turbine blades can be made to increase turbine efficiency of the turbine. The results and conclusions are presented for a study concerning the durability problems experienced with steam turbine blades.

  9. Experimental Investigation of Cavitation Induced Feedline Instability from an Orifice

    Science.gov (United States)

    Hitt, Matthew A.; Lineberry, David M.; Ahuja, Vineet; Frederick, Robert A,

    2012-01-01

    This paper details the results of an experimental investigation into the cavitation instabilities created by a circular orifice conducted at the University of Alabama in Huntsville Propulsion Research Center. This experiment was conducted in concert with a computational simulation to serve as a reference point for the simulation. Testing was conducted using liquid nitrogen as a cryogenic propellant simulant. A 1.06 cm diameter thin orifice with a rounded inlet was tested in an approximately 1.25 kg/s flow with inlet pressures ranging from 504.1 kPa to 829.3 kPa. Pressure fluctuations generated by the orifice were measured using a high frequency pressure sensor located 0.64 tube diameters downstream of the orifice. Fast Fourier Transforms were performed on the high frequency data to determine the instability frequency. Shedding resulted in a primary frequency with a cavitation related subharmonic frequency. For this experiment, the cavitation instability ranged from 153 Hz to 275 Hz. Additionally, the strength of the cavitation occur red as a function of cavitation number. At lower cavitation numbers, the strength of the cavitation instability ranged from 2.4 % to 7 % of the inlet pressure. However, at higher cavitation numbers, the strength of the cavitation instability ranged from 0.6 % to 1 % of the inlet pressure.

  10. Experimental investigation of the elasticity of the human diaphragm

    Directory of Open Access Journals (Sweden)

    Kaemmer Daniel

    2010-01-01

    Full Text Available Abstract Background Traumatic diaphragmatic ruptures affect mainly the left side. In an experimental study in human corpses we examined the stretch behaviour of the left and right diaphragmatic halves. Methods In a total of 8 male and 8 female corpses each diaphragmatic half was divided into 4 different segments. Each segments stretch behaviour was investigated. In steps of 2 N the stretch was increased up to 24 N. Results In the female the left diaphragm showed a stronger elasticity compared to the right. Additionally the left diaphragm in females showed a higher elasticity in comparison to the left in males. Traumatic diaphragmatic ruptures affect mostly the central tendineous part or the junction between tendineous and muscular part of the diaphragmatic muscle. Accordingly we found a lower elasticity in these parts compared with the other diaphragmatic segments. Conclusion In summary it can be said that albeit some restrictions we were able to determine the elasticity of different diaphragmatic segments quantitatively and reproduceably with our presented method. Thereby a comparison of results of different diaphragmatic segments as well as of both diaphragmatic halves and of both genders was possible

  11. Experimental and theoretical investigations of a 17 GHz RF gun

    CERN Document Server

    Brown, W J; Kreischer, K E; Pedrozzi, M; Shapiro, M A; Temkin, R J

    1999-01-01

    We report on experimental and theoretical investigations of a 17 GHz RF photocathode electron gun. This is the first photocathode electron gun to operate at a frequency above 2.856 GHz. The 1.5 cell, pi mode, copper cavity was tested with 50 ns pulses from a 17.150 GHz klystron amplifier built by Haimson Research Corp. A Bragg filter was used at the RF gun to reduce the reflection of parasitic modes back into the klystron. Coupling hole theory in conjunction with cold test measurements was used to determine the field profile in the RF gun. The particle in cell code MAGIC as well as coupled envelope equations were used to simulate the beam dynamics in the RF gun. With power levels of 4 MW, the on axis electric field at the cathode exceeds 300 MV/m, corresponding to an average accelerating gradient of 200 MV/m over the first half cell of the gun. Breakdown was observed at power levels above 5 MW. Electron bunches were produced by 20 mu J, 1 ps UV laser pulses impinging on the RF gun copper photocathode and were...

  12. Experimental Investigation of Energy Saving in Referigeration System

    Directory of Open Access Journals (Sweden)

    Inder Singh Nagar

    2014-08-01

    Full Text Available This Research deals with experimental investigation of energy saving in refrigeration system. We have all experienced a sensation of heat when passing behind a functioning refrigerator or air conditioner. The cause of this phenomenon is due to thr air condenser, a heat exchanger made up of tubes with air fins attached to the back of the device. This is where the cooling fluid condenses by releasing its heat into the ambient air. To utilize this heat, a water fine water droplet is project to absorb this ambient hot air to the atmosphere. so by decreasing condenser temperature we obtain the system’s energy consumption, humidification processes were initiated. The principle consists of saturating the ambient air in contact with the exchanger by projecting fine water droplets. Humidification of the air intensifies the heat exchange on the air side and reduces the cooling fluid’s condensation temperature. This lowers the compression rate in the cooling cycle and improves the compressor’s consumption of electrical power. The study is mainly focused on the Condenser to reduce the condenser work to save the electrical power.

  13. Experimental Investigations of Flow Past Spinning Circular Cylinders

    Science.gov (United States)

    Carlucci, Donald; Thangam, Siva

    1999-11-01

    Experimental investigations of flow past spinning circular cylinders were performed. Understanding and control of such flows are crucial to the design of efficient projectile based munitions. Experiments were conducted in an induction-type low-speed wind tunnel that includes a flow-conditioning section, a contraction with a 10:1 area ratio, a plexiglass test section having a nominal rectangular cross-section of 610 x 305 mm, a diffuser section, and two 7.5 hp fans which can provide a maximum velocity of 45 m/s in the test section. The right circular cylinder is spindle-mounted in the test section with a belt-driven motor. Primary instrumentation for this experiment includes pressure probes for mean-velocity measurements, hot-wire anemometer system for measuring turbulence statistics and a flow visualization system. Measured turbulence statistics include all components of the Reynolds stress tensor. Additionally, surface pressure distribution of the cylinder are mapped using static pressure taps and the pressure contribution to the drag force is computed. Mean velocity profiles and the Reynolds stress componets on the cylinder and the wake region are presented and compared with the available data in the literature. Issues related to the development of efficient and appropirate turbulence models are also addressed.

  14. Experimental Investigation on Effect of Adhesives on Thermoelectric Generator Performance

    Science.gov (United States)

    Singh, Baljit; Remeli, Muhammad Fairuz; Chet, Ding Lai; Oberoi, Amandeep; Date, Abhijit; Akbarzadeh, Aliakbar

    2015-06-01

    Thermoelectric generators (TEGs) convert heat energy into electricity. Currently, these devices are attached to heat exchangers by means of mechanical devices such as clamps or fixtures with nuts and bolts. These mechanical devices are not suitable for use in harsh environments due to problems with rusting and maintenance. To eliminate the need for such mechanical devices, various kinds of adhesives used to attach thermoelectric generators to heat exchangers are investigated experimentally in this work. These adhesives have been selected based on their thermal properties and also their stability to work in harsh environments to avoid damage to the integrity of the attachment over long periods of time. Stainless-steel plates were attached to a thermoelectric generator using the adhesives. The introduction of the adhesive as a means of attachment for thermoelectric generators contributes to increase the thermal resistance to heat transfer across the TEG. The adhesive layers increased the thermal resistance of the thermoelectric generator by 16% to 109%. This work examines the effect of the adhesives on the thermal performance and power output of a single thermoelectric generator for various heat inputs.

  15. Experimental Investigation on Characteristics of Polythene Waste Incorporated Concrete

    Directory of Open Access Journals (Sweden)

    J. Simson Jose

    2014-04-01

    Full Text Available The Disposal of large quantity of plastic cover may cause pollution of land, water bodies and air. The proposed concrete which is made up by adding plastic in concrete may help to reuse the plastic cover as one of the constituent’s material of concrete, to improve the certain properties of concrete. The properties of concrete as varying percentages of plastic will test for compressive strength and Split tensile strength and flexural strength shows that an appreciable improvement in tensile strength of concrete can be achieved by introducing cut pieces of plastic cover. This paper presents the experimental investigation of feasibility of polythene cover post consumer waste used for food packaging. The numbers of samples is prepared in M25 concrete mix with required water/ cement ratio. Plastic waste was converted in to fiber size form and added waste for three aspect ratios, is casted into desire shape and size as per requirement of the tests. Each specimen was cured for 7 days, 14 days, and 28 days. The workability of compression, tension and flexural tests were carried out. The results are compared with normal concrete was observed.

  16. Experimental investigation of supersonic flow over elliptic surface

    Science.gov (United States)

    Zhang, Qinghu; Yi, Shihe; He, Lin; Zhu, Yangzhu; Chen, Zhi

    2013-11-01

    The coherent structures of flow over a compression elliptic surface are experimentally investigated in a supersonic low-noise wind tunnel at Mach Number 3 using nano-tracer planar laser scattering (NPLS) and particle image velocimetry (PIV) techniques. High spacial resolution images and the average velocity profiles of both laminar inflow and turbulent inflow over the testing model were captured. From statistically significant ensembles, spatial correlation analysis of both cases is performed to quantify the mean size and orientation of large structures. The results indicate that the mean structure is elliptical in shape and structure angles in separated region of laminar inflow are slightly smaller than that of turbulent inflow. Moreover, the structure angle of both cases increases with its distance away from from the wall. POD analysis of velocity and vorticity fields is performed for both cases. The energy portion of the first mode for the velocity data is much larger than that for the vorticity field. For vorticity decompositions, the contribution from the first mode for the laminar inflow is slightly larger than that for the turbulent inflow and the cumulative contributions for laminar inflow converges slightly faster than that for turbulent inflow

  17. Experimental Investigation on Airfoil Shock Control by Plasma Aerodynamic Actuation

    International Nuclear Information System (INIS)

    An experimental investigation on airfoil (NACA64—215) shock control is performed by plasma aerodynamic actuation in a supersonic tunnel (Ma = 2). The results of schlieren and pressure measurement show that when plasma aerodynamic actuation is applied, the position moves forward and the intensity of shock at the head of the airfoil weakens. With the increase in actuating voltage, the total pressure measured at the head of the airfoil increases, which means that the shock intensity decreases and the control effect increases. The best actuation effect is caused by upwind-direction actuation with a magnetic field, and then downwind-direction actuation with a magnetic field, while the control effect of aerodynamic actuation without a magnetic field is the most inconspicuous. The mean intensity of the normal shock at the head of the airfoil is relatively decreased by 16.33%, and the normal shock intensity is relatively reduced by 27.5% when 1000 V actuating voltage and upwind-direction actuation are applied with a magnetic field. This paper theoretically analyzes the Joule heating effect generated by DC discharge and the Lorentz force effect caused by the magnetic field. The discharge characteristics are compared for all kinds of actuation conditions to reveal the mechanism of shock control by plasma aerodynamic actuation

  18. Experimental investigation of fatigue in a cantilever energy harvesting beam

    Science.gov (United States)

    Avvari, Panduranga Vittal; Yang, Yaowen; Liu, Peiwen; Soh, Chee Kiong

    2015-03-01

    Over the last decade, cantilever energy harvesters gained immense popularity owing to the simplicity of the design and piezoelectric energy harvesting (PEH) using the cantilever design has undergone considerable evolution. The major drawback of a vibrating cantilever beam is its vulnerability to fatigue over a period of time. This article brings forth an experimental investigation into the phenomenon of fatigue of a PEH cantilever beam. As there has been very little literature reported in this area, an effort has been made to scrutinize the damage due to fatigue in a linear vibrating cantilever PEH beam consisting of an aluminum substrate with a piezoelectric macro-fiber composite (MFC) patch attached near the root of the beam and a tip mass attached to the beam. The beam was subjected to transverse vibrations and the behavior of the open circuit voltage was recorded with passing time. Moreover, electro-mechanical admittance readings were obtained periodically using the same MFC patch as a Structural health monitoring (SHM) sensor to assess the health of the PEH beam. The results show that with passing time the PEH beam underwent fatigue in both the substrate and MFC, which is observed in a complimentary trend in the voltage and admittance readings. The claim is further supported using the variation of root mean square deviation (RMSD) of the real part of admittance (conductance) readings. Thus, this study concludes that the fatigue issue should be addressed in the design of PEH for long term vibration energy harvesting.

  19. Experimental investigation on bolting assemblies submitted to cyclic loads

    International Nuclear Information System (INIS)

    Design considerations may lead to the use of bolting or screwed connexions to join particular in sodium components of L.M.F.B. reactors. In these reactors, bolting connexions are to be chosen on criteria that may differ from those used in pressure vessel construction. For example in this case differential pressure is relatively low but thermal loads are cyclic and of large amplitude. Another particular problem is the often use of high strength materials for screws. These materials have higher elastic stress limit than strain hardening materials of the assembled components made often of austenitic steel. Because of thermal cycling the preload imposed during initial tightening can relaxe in some extent. Satisfactory operability of these components requires a minimal preload of the bolting connexion to be obtained during life time of the reactor. An experimental investigation on a representative H.M.20 bolting assembly was performed to document this behavior and to verify the applicability of design rules available in construction codes like RCC-MR (1). (orig.)

  20. Experimental investigation of mesoscale crack front triple line

    Science.gov (United States)

    Budzik, Michal K.; Jumel, Julien; Shanahan, Martin E. R.

    2014-02-01

    The aim of this paper is to investigate the mesoscale behavior and structure of an adhesive near the fracture front of an asymmetric joint consisting of carbon fiber/epoxy resin composites bonded with a relatively soft, epoxy adhesive. A single cantilever beam fracture test at constant separation rate gave steady-state crack propagation, details of which were followed by digital image correlation (DIC). A deformed, triple line region was found between the adhesive, air, and the composite, somewhat resembling a "wetting ridge," as found with a liquid meniscus in contact with a soft solid. Importantly, the partially separated bondline layer took part in (non-unidirectional) load transfer between adherends (and thus energy dissipation), contrary to common assumptions where the separated bondline is assumed no longer to play a structural role. A simple model, based on the Flamant contact mechanics approach, is proposed and compared with both a finite element solution and experimental data extracted from image correlation. The model points out the importance of two length scales: process zone extent and adhesive thickness, both being known to affect global properties of bonded structures.

  1. Theoretical and experimental investigation of coupled Ar-ion lasers

    Science.gov (United States)

    Jelonek, Mark P.

    1989-10-01

    A single mode laser theory was applied to two coupled Ar-ion lasers in Fabry-Perot resonators and the equations were solved numerically to predict intensity tuning curves and locking ranges for various types of mirror translations. The same theory was extended to model two modes in each cavity, which predicted a decrease in locking range as well as a mutually-reinforced hole burning minimum. With a single, uncoupled two mode He-Ne laser, the existence of the minimum was verified experimentally. Two multiline/multimode Ar-ion lasers were coupled through a common end mirror and the effect of coupling strength on phase locking was investigated by varying the reflectivity of that mirror. To mode coupling, interference fringe visibilities, output power, and the frequency and RF mode beat spectra were measured. The optimal phase locking occurred at about 25 percent coupling as determined by the maximum fringe visibilities produced by laser phase locking. That 25 percent coupling was the optimum coupling strength was also substantiated by fact that the maximum power output was also achieved at this point, and the appearance of the super cavity mode spacing verified that the behavior was due to phase locking. A passive cavity mode analysis of the three mirror Fabry-Perot resonator showed the system oscillated on the composite resonator frequency as well as the frequencies of both sub-resonators.

  2. Experimental investigation of premixed combustion within highly porous media

    International Nuclear Information System (INIS)

    This paper reports on an experimental investigation of premixed methane/air combustion stabilized within a reticulated partially stabilized zirconia foam burner that was performed. A flame holder was used to extend the stability range to allow a stable flame to be maintained for a variety of flow rate and equivalence ratio combinations. The stability range, temperature distributions, and emissions were examined over a range of equivalence ratios and flow rates. The flame was found to be axisymmetric for all conditions in which the reactants were sufficiently well mixed and the flow distribution was sufficiently uniform. Burning speeds were measured that were well in excess of the laminar flame speed. The axial temperature distribution (measured around the burner annulus) in the postflame zone was found to be relatively insensitive to flow rate but dependent upon the burner core length. Very low concentrations of NOx were found for fuel/air equivalence ratios of less than about 0.9. Measured O2 concentrations followed the equilibrium trend relatively well

  3. Experimental investigation on light propagation through apple tissue structures

    Science.gov (United States)

    Askoura, Mohamed Lamine; Piron, Vianney; Vaudelle, Fabrice; L'Huillier, Jean-Pierre; Madieta, Emmanuel; Mehinagic, Emira

    2015-07-01

    The interaction of light with biological materials, such as fruits and vegetables, is a complex process which involves both absorption, and scattering events at different scales. Measuring the optical properties of a fruit allows understanding the physical and chemical characteristics. In this paper, an optical bench based on the use of a continuous laser source and a CCD camera was developed to study the light diffusion inside apple tissue structures. The method refers to the well-known steady-state spatially resolved method. First, the optoelectronics system was tested with a tissue phantom in order to show the optimal sensing range required to obtain the best estimated optical properties. Second, experimental results were obtained using peeled and unpeeled apples as interrogated tissues. The data were confronted with a diffusion model in order to extract the optical properties at two wavelengths of 633, and 852 nm. To better understand the effect of the apple tissue structures, investigations into the propagation of light through a half cut apple were also performed.

  4. Field and laboratory emission cell automation and control system for investigating surface chemistry reactions.

    Science.gov (United States)

    Flemmer, Michael M; Ham, Jason E; Wells, J R

    2007-01-01

    A novel system [field and laboratory emission cell (FLEC) automation and control system] has been developed to deliver ozone to a surface utilizing the FLEC to simulate indoor surface chemistry. Ozone, humidity, and air flow rate to the surface were continuously monitored using an ultraviolet ozone monitor, humidity, and flow sensors. Data from these sensors were used as feedback for system control to maintain predetermined experimental parameters. The system was used to investigate the chemistry of ozone with alpha-terpineol on a vinyl surface over 72 h. Keeping all other experimental parameters the same, volatile organic compound emissions from the vinyl tile with alpha-terpineol were collected from both zero and 100 ppb (parts per 10(9)) ozone exposures. System stability profiles collected from sensor data indicated experimental parameters were maintained to within a few percent of initial settings. Ozone data from eight experiments at 100 ppb (over 339 h) provided a pooled standard deviation of 1.65 ppb and a 95% tolerance of 3.3 ppb. Humidity data from 17 experiments at 50% relative humidity (over 664 h) provided a pooled standard deviation of 1.38% and a 95% tolerance of 2.77%. Data of the flow rate of air flowing through the FLEC from 14 experiments at 300 ml/min (over 548 h) provided a pooled standard deviation of 3.02 ml/min and a 95% tolerance range of 6.03 ml/min. Initial experimental results yielded long term emissions of ozone/alpha-terpineol reaction products, suggesting that surface chemistry could play an important role in indoor environments. PMID:17503934

  5. Geophysical investigation: New Production Reactor Complex, Idaho National Engineering Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Filipkowski, F.; Blackey, M.; Davies, D.; Levine, E.N.; Murphy, V. [Weston Geophysical Corp., Westboro, MA (US)

    1991-12-01

    Seismic crosshole and downhole velocity measurements were performed for two borehole arrays approximately 300 feet deep in conjunction with verticality measurements and geophysical logging of borehole WO-2 (to a depth of 4,960 feet) at the NPR site of the INEL. Past studies show that the site area is covered by a thin layer of soil which overlies numerous basalt flows interrupted by sandy and clayey interbeds. Compressional and shear wave velocities computed for these arrays revealed low velocity zones at the following elevation ranges for crosshole array No. 1: 4,893 feet to 4,873 feet (basalt rubble zone) and 4,705 feet to 4,686 feet (sediment interbed). Corresponding elevation ranges for crosshole array No. 2 include: 4,830 feet to 4,815 feet (sediment interbed), 4,785 feet to 4,765 feet (highly vesicular and fractured basalt), 4,715 feet to 4,705 feet (basalt rubble zone), and 4,672 feet to 4,667 feet (sediment interbed). In general, crosshole velocity data correlated between arrays with velocity differences possibly explained by localized lithologic changes. Due to scatter in the downhole velocity data, only velocity averages were computed. However, these downhole velocities correlated to the approximate mean crosshole velocity values and therefore independent confirmed the crosshole data. Geophysical logging of well WO-2 included natural gamma, neutron, and compensated density logs to a depth of 4,960 feet at which a viscous borehole fluid inhibited further investigation. Second runs of small sections of these logs were repeated satisfactorily for confirmation of certain anomalous areas.

  6. Sesame seed allergy: Clinical manifestations and laboratory investigations

    Directory of Open Access Journals (Sweden)

    Fazlollahi MR.

    2007-10-01

    Full Text Available Background: Plant-origin foods are among the most important sources of food allergic reactions. An increase in the incidence of sesame seed allergy among children and adults has been reported in recent years. The aim of this preliminary study was to investigate the prevalence, importance and clinical manifestations of sesame allergy among Iranian patients.Methods: In a cross-sectional survey, 250 patients with suspected IgE-mediated food allergies completed a questionnaire and underwent skin prick tests with sesame extract as well as cross-reacting foods (walnut, soya and peanut. Total IgE and sesame-specific IgE levels were measured. Patients with positive skin test reactions and/or IgE specific for sesame without clinical symptoms were considered sensitive to sesame. The patients who also had clinical symptoms with sesame consumption were diagnosed as allergic to sesame.Results: Of the 250 patients enrolled in this study, 129 were male and 121 female, with a mean age of 11.7 years. The most common food allergens were cow's milk, egg, curry, tomato and sesame. Sesame sensitivity was found in 35 patients (14.1%. Only five patients (2% had sesame allergy. Sesame-sensitive patients had a significantly higher frequency of positive prick test to cross-reacting foods when compared to non-sensitized patients (p=0.00. The type of symptom was independent of gender and age of the patients, but urticaria and dermatitis-eczema were significantly more frequent in sensitized patients (p=0.008.Conclusions: This is the first study addressing the prevalence of sesame seed allergy in Iranian population. We found sesame to be a common and important cause of food allergy. The panel of foods recommended for use in diagnostic allergy tests should be adjusted.

  7. Morphodynamics of the exit of a cutoff meander: experimental findings from field and laboratory studies

    OpenAIRE

    Le Coz, J.; Michalkova, M.; Hauet, A.; Comaj, M.; Dramais, G.; Holubova, K.; Piégay, H.; Paquier, A.

    2010-01-01

    The morphological evolution of the entrances and exits of abandoned river channels governs their hydrological connectivity. The study focusses on flow and sediment dynamics in the exit of a cut-off meander where the downstream entrance is still connected to the main channel, but the upstream entrance is closed. Two similar field and laboratory cases were investigated using innovative velocimetry techniques (acoustic Doppler profiling, image analysis). Laboratory experiments were conducted wit...

  8. A Global Remote Laboratory Experimentation Network and the Experiment Service Provider Business Model and Plans

    Directory of Open Access Journals (Sweden)

    Tor Ivar Eikaas

    2003-07-01

    Full Text Available This paper presents results from the IST KAII Trial project ReLAX - Remote LAboratory eXperimentation trial (IST 1999-20827, and contributes with a framework for a global remote laboratory experimentation network supported by a new business model. The paper presents this new Experiment Service Provider business model that aims at bringing physical experimentation back into the learning arena, where remotely operable laboratory experiments used in advanced education and training schemes are made available to a global education and training market in industry and academia. The business model is based on an approach where individual experiment owners offer remote access to their high-quality laboratory facilities to users around the world. The usage can be for research, education, on-the-job training etc. The access to these facilities is offered via an independent operating company - the Experiment Service Provider. The Experiment Service Provider offers eCommerce services like booking, access control, invoicing, dispute resolution, quality control, customer evaluation services and a unified Lab Portal.

  9. Advanced Laboratory at Texas State University: Error Analysis, Experimental Design, and Research Experience for Undergraduates

    Science.gov (United States)

    Ventrice, Carl

    2009-04-01

    Physics is an experimental science. In other words, all physical laws are based on experimentally observable phenomena. Therefore, it is important that all physics students have an understanding of the limitations of certain experimental techniques and the associated errors associated with a particular measurement. The students in the Advanced Laboratory class at Texas State perform three detailed laboratory experiments during the semester and give an oral presentation at the end of the semester on a scientific topic of their choosing. The laboratory reports are written in the format of a ``Physical Review'' journal article. The experiments are chosen to give the students a detailed background in error analysis and experimental design. For instance, the first experiment performed in the spring 2009 semester is entitled Measurement of the local acceleration due to gravity in the RFM Technology and Physics Building. The goal of this experiment is to design and construct an instrument that is to be used to measure the local gravitational field in the Physics Building to an accuracy of ±0.005 m/s^2. In addition, at least one of the experiments chosen each semester involves the use of the research facilities within the physics department (e.g., microfabrication clean room, surface science lab, thin films lab, etc.), which gives the students experience working in a research environment.

  10. Accelerator laboratories: development centers for experimental physics and technology in Mexico

    International Nuclear Information System (INIS)

    Three years ago in this Nuclear Center the author and Professor Graef expounded the inception and development of experimental physics and new techniques centered about laboratories and equipped in our country with positive ion accelerators. Extracted here is the information on the laboratories that have allowed professional training as well as the furtherance of scientific productivity in each group. An additional proposal as to how the technical groups knowledgeable in advanced technology might contribute significantly to adequate preparation of youth at the intermediate level able to generate innocuous micro industries in their own neighbourhood. (Author). 5 refs, 2 figs, 2 tabs

  11. Watching what's coming near increases tactile sensitivity: An experimental investigation.

    Science.gov (United States)

    Van der Biest, Lien; Legrain, Valéry; Paepe, Annick De; Crombez, Geert

    2016-01-15

    During medical examinations, doctors regularly investigate a patient's somatosensory system by approaching the patient with a medical device (e.g. Von Frey hairs, algometer) or with their hands. It is assumed that the obtained results reflect the true capacities of the somatosensory system. However, evidence from crossmodal spatial research suggests that sensory experiences in one modality (e.g. touch) can be influenced by concurrent information from other modalities (e.g. vision), especially near the body (i.e. in peripersonal space). Hence, we hypothesized that seeing someone approaching your body could alter tactile sensitivity in that body-part. In the In Vivo Approaching Object (IVAO) paradigm, participants detected and localized threshold-level vibrotactile stimuli administered on the left of right hand (=tactile targets). In Experiment 1, this was always preceded by the experimenter approaching the same (congruent trials) or the other (incongruent trials) hand with a pen (=visual cue). In Experiment 2, a condition was added in which a point further away from the hands (also left vs. right) was approached. Response Accuracy was calculated for congruent and incongruent trials (Experiment 1 & 2) and compared between the close and far condition (Experiment 2). As expected, Response Accuracy was higher in congruent trials compared to incongruent trials, but only near the body. As a result, evidence was found for a crossmodal interaction effect between visual and tactile information in peripersonal space. These results suggest that somatosensory evaluations-both medical or research-based-may be biased by viewing an object approaching the body. PMID:26475955

  12. Experimental and theoretical investigations of a 17 GHz RF gun

    International Nuclear Information System (INIS)

    We report on experimental and theoretical investigations of a 17 GHz RF photocathode electron gun. This is the first photocathode electron gun to operate at a frequency above 2.856 GHz. The 1.5 cell, π mode, copper cavity was tested with 50 ns pulses from a 17.150 GHz klystron amplifier built by Haimson Research Corp. A Bragg filter was used at the RF gun to reduce the reflection of parasitic modes back into the klystron. Coupling hole theory in conjunction with cold test measurements was used to determine the field profile in the RF gun. The particle in cell code MAGIC as well as coupled envelope equations were used to simulate the beam dynamics in the RF gun. With power levels of 4 MW, the on axis electric field at the cathode exceeds 300 MV/m, corresponding to an average accelerating gradient of 200 MV/m over the first half cell of the gun. Breakdown was observed at power levels above 5 MW. Electron bunches were produced by 20 μJ, 1 ps UV laser pulses impinging on the RF gun copper photocathode and were measured with a Faraday cup to have up to 0.1 nC of charge. This corresponds to a peak current of about 100 A, and a density at the cathode of 8.8 kA/cm2. Multiple output electron bunches were obtained for multiple laser pulses incident on the cathode. Phase scans of laser-induced electron emission reveal an overall phase stability of better than ±20 deg. , corresponding to ±3 ps synchronization of the laser pulses to the phase of the microwave field. A Browne-Buechner magnetic spectrometer indicated that the RF gun generated 1 MeV electrons with a single shot rms energy spread of less than 2.5%, in good agreement with theoretical predictions

  13. Experimental investigation and mechanical modelling of zircaloy-4 stress corrosion cracking

    International Nuclear Information System (INIS)

    In Pressurised Water Reactor fuel assemblies, cladding tubes constitute the first safety barriers against the fission product dissemination. It is therefore essential to ensure their integrity under all the reactor operating conditions. During an important loading, resulting from severe reactor power transients, clad failures can be induced by a Stress Corrosion Cracking phenomenon (SCC) due to the combined action of mechanical loading and gaseous fission products generated by the fuel pellets. The aim of our work is to study the role played by different parameters on the SCC phenomenon of Zircaloy-4 claddings. It is made up of three complementary parts: - the modelling of local mechanical fields applied during laboratory tests; - the design of specific SCC experiments to investigate the influence of several mechanical parameters; - the observation of the damage mechanisms occurring during these different experiments. Coupling mechanical modelling and laboratory tests allowed to obtain some local information which cannot be obtained experimentally. A hierarchical approach was then used to develop accurate constitutive laws of the stress-relieved Zircaloy-4 alloy. The constitutive equations derived from this approach were fitted to the mechanical loading applied during the experiments. The specific SCC tests results and SEM observations proved the existence of a time incubation period, which lasts for an important part of the lifetime measured in the SCC pressurization tests. This incubation period is closely related to the experimental conditions of the laboratory tests. However the incubation period must be distinguished from the actual SCC mechanisms and corresponds to the time required for the metal surface to strip of its oxide layer by mechanical cracking and/or attack of zircon. First results obtained on pre-cracked samples showed that this stage, which introduces an artefact in the experimental test analysis, can be suppressed. Moreover, we have borne out that initiation and propagation of SCC cracks can be very fast when metal is laid bare and when iodine is present. (author)

  14. Analysis of Verbal Interactions during an Extended, Open-Inquiry General Chemistry Laboratory Investigation

    Science.gov (United States)

    Krystyniak, Rebecca A.; Heikkinen, Henry W.

    2007-01-01

    This study explores effects of participation by second-semester college general chemistry students in an extended, open-inquiry laboratory investigation. Verbal interactions among a student lab team and with their instructor over three open-inquiry laboratory sessions and two non-inquiry sessions were recorded, transcribed, and analyzed. Coding…

  15. Investigating the Effect of Argument-Driven Inquiry in Laboratory Instruction

    Science.gov (United States)

    Demircioglu, Tuba; Ucar, Sedat

    2015-01-01

    The aim of this study is to investigate the effect of argument-driven inquiry (ADI) based laboratory instruction on the academic achievement, argumentativeness, science process skills, and argumentation levels of pre-service science teachers in the General Physics Laboratory III class. The study was conducted with 79 pre-service science teachers.…

  16. Cold Climate Foundation Retrofit Experimental Hygrothermal Performance. Cloquet Residential Research Facility Laboratory Results

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Harmon, Anna C. [NorthernSTAR, St. Paul, MN (United States)

    2015-04-09

    This project was funded jointly by the National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL). ORNL focused on developing a full basement wall system experimental database to enable others to validate hygrothermal simulation codes. NREL focused on testing the moisture durability of practical basement wall interior insulation retrofit solutions for cold climates. The project has produced a physically credible and reliable long-term hygrothermal performance database for retrofit foundation wall insulation systems in zone 6 and 7 climates that are fully compliant with the performance criteria in the 2009 Minnesota Energy Code. These data currently span the period from November 10, 2012 through May 31, 2014 and are anticipated to be extended through November 2014. The experimental data were configured into a standard format that can be published online and that is compatible with standard commercially available spreadsheet and database software.

  17. Experimental investigations of biomass gasification with carbon-dioxide

    Science.gov (United States)

    Sircar, Indraneel

    A sustainable energy cycle may include enhanced utilization of solar energy and atmospheric CO2 to produce biomass and enhanced utilization of exhaust CO2 from power plants for synthetic gas production. The reaction of carbon with CO2 is potentially one of the important processes in a future sustainable carbon cycle. Reactions involving carbon and CO2 are also relevant to the chemical process and metal industries. Biomass char has been recognized as a present and future alternative to fossil-fuels for energy production and fuel synthesis. Therefore, biomass char gasification with CO2 recycling is proposed as a sustainable and carbon-neutral energy technology. Biomass char is a complex porous solid and its gasification involves heat and mass transfer processes within pores of multiple sizes from nanometer to millimeter scales. These processes are coupled with heterogeneous chemistry at the internal and external surfaces. Rates for the heterogeneous carbon gasification reactions are affected by inorganic content of the char. Furthermore, pore structure of the char develops with conversion and influences apparent gasification rates. Effective modeling of the gasification reactions has relied on the best available understanding of diffusion processes and kinetic rate property constants from state of the art experiments. Improvement of the influences of inorganic composition, and process parameters, such as pressure and temperature on the gasification reaction rates has been a continuous process. Economic viability of gasification relies on use of optimum catalysts. These aspects of the current status of gasification technologies have motivated the work reported in this dissertation. The reactions between biomass chars and CO2 are investigated to determine the effects of temperature and pressure on the reaction rates for large char particles of relevance to practical gasification technologies. An experimental apparatus consisting of a high-pressure fixed-bed reactor with product gas sampling for tracking the reaction progress, supported by independent gravimetric measurements of mass loss, is described. The effects of pressure and temperature on the char-CO2 reaction are investigated at elevated pressures up to 10 atm. Measurements of reaction rates at multiple temperatures and pressures for a low-ash pinewood char are presented. Kinetic rate parameters for the char-CO2 reaction are reported with detailed uncertainty calculations and discussed in the context of the structural changes of the char with mass loss. The effects of pressure and temperature on the internal mass transfer processes and the intrinsic reaction rates are assessed using Thiele analysis for non-isothermal particles with the nth order and the Langmuir-Hinshelwood kinetic rate models. The effects of potassium, calcium and iron catalysts on the CO2 gasification rates of an activated coconut char are investigated. A catalyst treatment method for obtaining high catalyst loadings (~12 wt. %) is described. The effects of the catalysts on the surface reaction rates and the activation energies are reported. The results of this study are encouraging in the context of potential future discovery of a viable low-temperature catalytic gasification process for sustainable use of biomass as a renewable energy resource. Utilization of plant based substances such as citric acid to provide higher catalytic activity and the potential for utilizing the high initial activity of iron by using rust proofing compounds for maintaining high reactivity are recommended for further development.

  18. “Golden oldies” in a laboratory course in the experimental analysis of behavior

    OpenAIRE

    Zuriff, G E

    2005-01-01

    A common problem in teaching undergraduate courses in the experimental analysis of behavior (EAB) is that the contemporary research literature is largely not comprehensible to most undergraduates. A suggested solution is the use of research articles from the early days of EAB. These are not only easy to understand but provide additional educational benefits. A reading list and an organizational structure for an undergraduate laboratory course in EAB are suggested.

  19. "Golden oldies" in a laboratory course in the experimental analysis of behavior.

    Science.gov (United States)

    Zuriff, G E

    2005-01-01

    A common problem in teaching undergraduate courses in the experimental analysis of behavior (EAB) is that the contemporary research literature is largely not comprehensible to most undergraduates. A suggested solution is the use of research articles from the early days of EAB. These are not only easy to understand but provide additional educational benefits. A reading list and an organizational structure for an undergraduate laboratory course in EAB are suggested. PMID:22478440

  20. Experimental Verification of the Petroelastic Model in the Laboratory - Fluid Substitution and Pressure Effects.

    OpenAIRE

    Rasolofosaon P. N.J.; Zinszner B.

    2012-01-01

    The poroelastic model is a major component in the workflows for the interpretation of time-lapse (or 4D) seismic data in terms of fluid repartition and/or pressure variation during the exploitation of reservoirs. This model must take into account both the fluid substitution effect and the pressure variation effect on the measured seismic parameters (velocities, impedance). This paper describes an experimental verification in the laboratory of this model. Regarding fluid substitution, Biot- Ga...

  1. Experimental investigation of reinforced-concrete Category I structures at high load levels

    International Nuclear Information System (INIS)

    A US Nuclear Regulatory Commission-funded experimental program designed to obtain information on the structural behavior of reinforced-concrete buildings has been underway at the Los Alamos National Laboratory since 1980. This information will aid the NRC in evaluating the seismic capacities of existing Seismic Category I buildings. Scale models of reinforced-concrete shear walls and buildings were subjected to static and dynamic tests. Simulated seismic tests were conducted on model structures constructed to two scales (1/30 and 1/10), permitting an evaluation of the effect of scale in experimental investigations of reinforced-concrete structures. Monotonic and cyclic quasistatic tests provide information on strength, stiffness, strength and stiffness degradation, ductility, and general load-deflection behavior up to the ultimate load. The dynamic tests yielded information on natural frequencies, equivalent viscous damping values, initial stiffness and stiffness degradation, and general response behavior. These experimental investigations have indicated that sine-sweep tests are not suitable for reinforced-concrete structures and that the initial stiffness of shear wall structures is less than predicted when assuming an uncracked concrete section

  2. Laboratory investigations on hydrate formation and dissociation in sediments - analogies and differences to natural systems

    Science.gov (United States)

    Schicks, J. M.; Spangenberg, E.; Priegnitz, M.; Heeschen, K. U.; Thaler, J.; Abendroth, S.

    2014-12-01

    In natural sediments changes in pressure and temperature may induce the dissociation of naturally occurring gas hydrates. The dissociation of the solid hydrates as well as the increase of a gas phase due to hydrate dissociation may cause or facilitate geo hazards such as slope failure [1]. Therefore, the understanding of hydrate distribution, dissociation and (re-) formation processes which in turn may alter the geomechanical properties of the sediments are of great importance for the prediction on hydrate behavior. During the last decades both, hydrate formation and dissociation, have been studied manifold in laboratory experiments to get a better understanding of these processes. However, the experimental set ups and chosen conditions such as pressure, temperature, sediments, and water saturation vary significantly and do not always simulate natural systems. Within the German national project SUGAR we developed a large LAboratory Reservoir Simulator LARS to study hydrate behavior in sediments. LARS has a total volume of 425 L and has been successfully equipped with an electrical resistivity tomography (ERT). The hydrates form from methane saturated saline water in absence of a free gas phase. Measurements of the dissolved methane at the sample in- and outlet together with temperature monitoring at different locations inside the sediment and ERT measurements are used to describe and characterize the formation process. The ERT and temperature measurements allow for a detection of spatial differences. It could be shown that in this laboratory simulation hydrate forms as it is assumed for natural scenarios. Dissociation processes induced by pressure decrease or temperature increase as well as the consecutive migration of gases and fluids were also studied. To complete the understanding of decisive factors on hydrate formation and fluid flow we investigated the influence of grain sizes on hydrate formation and the influence of hydrate saturation on permeability. In this contribution we present the experimental set up and discuss the results with regard to the analogies and differences to natural systems. [1] Jürgen Mienert, Maarten Vanneste, Stefan Bünz, Karin Andreassen, Haflidi Haflidason, Hans Petter Sejrup, Marine and Petroleum Geology 22 (2005) 233-244.

  3. Bond behaviour of reinforcing bars in UHPFRC: Experimental investigation

    OpenAIRE

    MARCHAND, Pierre; BABY, Florent; KHADOUR, Aghiad; BATTESTI, Thomas; RIVILLON, Philippe; Quiertant, Marc; Nguyen, Hong-Hai; GENEREUX, Grégory; DEVEAUD, Jean-Paul; Simon, Alain; TOUTLEMONDE, François

    2015-01-01

    This paper deals with the experimental determination of the bond behaviour between ultra-high performance fiber-reinforced concrete (UHPFRC) and reinforcing bars (rebars). An experimental campaign has been carried out to assess the bond behaviour considering different rebar diameters, different embedment lengths and different concrete covers. A relationship between bond strength, compressive strength and rebar diameter has been drawn from the results of this campaign and results found in the ...

  4. Experimental investigation of gas storage properties of black shales

    OpenAIRE

    Gasparik, Matus

    2013-01-01

    In exploration for shale gas, reliable estimations of Gas-In-Place (GIP) and portion of technically recoverable resource pose a challenging task. Improvement of our understanding of gas stogare capacity of carbonaceous shales and its evolution during geological history requires carefully designed experiments to obtain reliable experimental data. Moreover, the experimental conditions have to cover a range representative of the in-situ reservoir conditions. This thesis, which was conducted duri...

  5. Experimental investigation of the cyclic behaviour of unreinforced masonry spandrels

    OpenAIRE

    Beyer, Katrin; Abo El Ezz, Ahmad; Dazio, Alessandro

    2010-01-01

    In unreinforced masonry (URM) walls the vertical piers are connected by horizontal spandrel elements. Numerical simulations have shown that spandrels influence significantly the global wall behaviour under seismic loading. Despite their importance, experimental data on the cyclic behaviour of these spandrels is very scarce. The lack of experimental data prevented in the past the validation of numerical and mechanical models regarding the cyclic behaviour of masonry spandrels. For this reason ...

  6. Experimental investigation of two-dimensional antiferromagnetic systems

    Science.gov (United States)

    Woodward, Frank Matthew

    Quantum fluctuations have a profound effect on the bulk properties of magnetic systems, particularly in low spatial dimension. For example, 1D chains with half integral spins have a gapless excitation spectrum while whole integer spin chains have a (Haldane) gap. The quantum critical behavior of the S = 1/2 2D system is thought to be the origin of high TC superconductivity. Molecular magnets are engineered materials where spin, interaction strength, or dimensionality can be tuned for experimental exploration of magnetism. A conscious effort was made to pick chemical motifs known to generate a quasi two dimensional Heisenberg system and attempt to exploit these motifs by designing classes of compounds based upon them. Creating many similar systems and observing changes in magnetism as a result in changes of chemical structure provides for the development of a phenomenological model of magnetostructural correlations which can then be verified by calculation. This dissertation discusses two distinct classes of antiferromagnetic systems, each based upon entirely different chemical motifs, both exhibiting the desired two dimensional Heisenberg antiferromagnetic behavior. One class is based upon copper tetrabromide: (5gammaAP)2CuBr4 where 5gammaAP = 2-amino-5-gamma-pyridinium with gamma = chloro, bromo, or methyl substituents. These materials are shown, by bulk magnetization and calorimetry studies to possess an exchange strength on the order of J ? -7 to -9 K and ordering temperatures in the range of TN ? 3.5 to 5 K. In the ordered state, these materials are shown to possesses a weak 3D exchange interaction, and exhibit a spin-flop transition to long range order in the magnetism. The other class under investigation is based upon copper pyrazine: Cu(pz) 2(ClO4)2, Cu(pz)2(BF6) 2, and [Cu(pz)2(NO3)](PF6). By bulk magnetic measurements of powder and single crystal samples they are shown to be a very good approximation of the 2D QHAF model. The two dimensional magnetic exchange, J, ranges from -10 K to -20 K while the observed magnetic ordering temperatures, TN range from 4.1 K to 3 K. The nature of the ordering transition in these materials, unlike the copper bromides, has yet to be determined and is fertile ground for further research.

  7. Experimental Investigation on Strength Characteristics of Binary Blended Concrete

    Directory of Open Access Journals (Sweden)

    MD. Hashmath

    2014-12-01

    Full Text Available An experimental investigation has been carried out to assess the behavior of concrete beams blended with steel crimped fiber and flyash subjected to combined torsion-bending-shear with longitudinal reinforcement. The concrete is binary blended with 15% of fly ash by weight of cement as partial replacement of cement and addition of 0%, 0.5%, 0.75%, 1% of crimped steel fibers with aspect ratio of 80 are used for the study purpose. Compressive strength of concrete is measured by testing standard cubes (150mm x 150mm x 150mm at the age of 28 days, the combined torsion-bending-shear strength is measured by testing beams of size 100x100mm and length 1200mm with a bracket attached at center of size 100x100x300mm.This bracket is adequately reinforced to avoid any failure at joint. The tests were conducted on 12 beams for varying percentages of steel fibers and studied for their behavior under combined torsion-bending-shear. The study involved the influence of fiber addition on the ultimate torsion-bending-shear strength of beams.Test results indicated that fibrous concrete beams exhibited improved overall performance with respect to corresponding non-fibrous beams. Flyash with steel fiber has shown considerable improvement in the compressive and torsion-bending-shear strength of concrete. From the test results it is observed that the concrete mix with 15% fly ash replacement of cement of M30 grade concrete mixture has shown maximum compressive strength of 47 MPa at 28 days. Concrete mixture with 15% fly ash replacement of cement along with 0.75% of crimped steel fibers has shown significant improvement in various properties at the age 0f 28 days indicated by 38% increase in compressive strength and 58% increase in the combined torsion-bending-shear strength of concrete. Hence binary blended crimped steel fiber reinforced concrete with 15% fly ash with 0.75 % steel fibers is a novel material having superior performance characteristics compared with conventional concrete.

  8. Numerical and experimental investigation of leaks in viscoelastic pressurized pipes

    Directory of Open Access Journals (Sweden)

    S. Meniconi

    2012-09-01

    Full Text Available This paper extends the analysis concerning the importance in numerical models of unsteady friction and viscoelasticity to transients in plastic pipes with an external flow due to a leak. In fact recently such a benchmarking analysis has been executed for the cases of a constant diameter pipe (Duan et al., 2010, a pipe with a partially closed in-line valve (Meniconi et al., 2012a, and a pipe with cross-section changes in series (Meniconi et al., 2012b. The analysis is based on laboratory tests carried out at the Water Engineering Laboratory (WEL of the University of Perugia, Italy, and numerical experiments by means of different 1-D numerical models. The results show that it is crucial to take into account the viscoelasticity to simulate the main characteristics of the transients, also in the case of a damaged pipes.

  9. Experimental investigation of the displacement of viscous fluids from porous media

    Science.gov (United States)

    Baryshnikov, Nikolay; Belyakov, Georgy; Tairova, Aliya; Turuntaev, Sergey

    2015-04-01

    The problems of increase of oil recover by means of a reservoir flooding are considered as a basis for the study. The results of laboratory experimental investigations of different-viscosity and immiscible Newtonian fluid flows through porous media are presented. The investigations were carried out for a Hele-Shaw cell filled by two types of porous media. The basic difference from the previous studies is the observation of the flow after break-through of the displacing fluid into sink. A series of qualitative and quantitative results which clarify the physics of immiscible fluid flows through capillaries and porous media were obtained in the course of the experimental investigations. Experiments carried out confirm the proposition of the Saffman-Taylor theory concerning the instability of the displacement front when a lower-viscosity fluid displaces a higher-viscosity fluid. It was found that the unstable flow pattern is determined not by the length of the capillary wave which disrupts the flow but by the geometry of the pore space. Experiments on the displacement of oil from capillary by water show that the oil can be completely driven out of the capillary due to the development of wavy flow after the displacing fluid arrives at the capillary outlet.

  10. Flame propagation in dust clouds. Numerical simulation and experimental investigation

    OpenAIRE

    Skjold, Trygve

    2014-01-01

    This dissertation describes the development and validation of a methodology for estimating the consequences of accidental dust explosions in complex geometries. The approach adopted entails the use of results from standardized tests in 20-litre explosion vessels as input to the combustion model in a computational fluid dynamics (CFD) code, and the subsequent validation of the model system by comparing with results from laboratory and large-scale experiments. The PhD project includes...

  11. Experimental Investigation of Use of Microsilica in Self Compacting Concrete

    OpenAIRE

    Mr.Ashok P. Kalbande; Prof. R.V.R.K. Prasad

    2012-01-01

    This paper is described Project in detail and presents laboratory observation. Microsilica is used as a 10% replacement of cement by weight. Various test were conducted on fine aggregate & coarse aggregate, to determine specific gravity, bulk density, fineness modulus of aggregate, concrete mix proportion design using this parameter..For conventional concrete water cement ratio of 0.4 and for microsilica concrete is increased water contain about 20liter/m3. Water demand increases in ...

  12. Testing geochemical models of bentonite pore water evolution against laboratory experimental data

    International Nuclear Information System (INIS)

    The determination of a bentonite pore water composition and understanding its evolution with time underpins many radioactive waste disposal issues, such as buffer erosion, canister corrosion, and radionuclide solubility, sorption, and diffusion, inter alia. Previous modelling approaches have tended to ignore clay dissolution-precipitation reactions, a consequence of which is that montmorillonite is theoretically preserved indefinitely in the repository system. Here, we investigate the applicability of an alternative clay pore fluid evolution model, that incorporates clay dissolution-precipitation reactions as an integral component and test it against well-characterised laboratory experimental data, where key geochemical parameters, Eh and pH, have been measured directly in compacted bentonite. Simulations have been conducted using different computer codes (Geo-chemist's Workbench, PHREEQC, and QPAC) to test the applicability of this model. Thermodynamic data for the Gibb's free energy of formation of MX-80 smectite used in the calculations were estimated using two different methods ('Polymer' and 'Vieillard' Models).Simulations of 'end-point' pH measurements in batch bentonite-water slurry experiments showed different pH values according to the complexity of the system studied. The most complete system investigated revealed pH values were a strong function of partial pressure of carbon dioxide, with pH increasing with decreasing PCO2 (with log PCO2 values ranging from -3.5 to -7.5 bars produced pH values ranging from 7.9 to 9.6). A second set of calculations investigated disequilibrium between clay and pore fluid in laboratory squeezing cell tests involving pure water (pH = 9.0) or a 1 M NaOH solution (pH = 12.1). Simulations carried out for 100 days (the same timescale as the experiments) showed that smectite remained far from equilibrium throughout, and that the lowering of pH due to smectite hydrolysis was trivial. However, extending the duration of the simulations to that required for clay-fluid equilibrium, necessitated timescales of 7 and 65. years for pure water and 1 M NaOH, respectively, but again produced relatively minor reduction in pH (in the order of 0.1-0.2 pH units). If the (equilibrium) precipitation of secondary minerals was included in the simulations, then not only was the clay-fluid equilibration period extended dramatically (from 7 to 360 years for pure water, and from 65 to 2600. years for 1 M NaOH), but concomitant changes in pH were significant, decreasing from 9.0 to 8.6 (pure water) and from 12.1 to 9.0 (1 M NaOH). Repetition of these latter calculations using an alternative method for ?Gf0 smectite produced an increase in equilibration time for reaction with 1 M NaOH from 2600 to 5000 years, highlighting the potential effects of the uncertainty in thermodynamic data for smectite. A final set of calculations was carried out to investigate both the time- and space-dependent variations in pore fluid composition in laboratory in-diffusion experiments conducted for over 1200 days, initially with pure water and 'spiked' after 271 days with a Na-Ca-OH-Cl solution (pH = 11.7). Here, the sensitivity of the results to both variations in a number of parameters/conditions (porosity, reaction rate of secondary minerals, the degree of mixing of the external fluid reservoirs in the experiments, the effective diffusion coefficient) and the inclusion/exclusion of key processes (clay hydrolysis, secondary mineral precipitation, ion exchange, clay edge protonation-deprotonation reactions) was investigated. These calculations confirmed that smectite dissolution-precipitation reactions alone have an insignificant impact upon pH buffering over laboratory timescales and that the pH buffering observed is most likely controlled by clay protonation-deprotonation reactions, and kinetic secondary mineral (brucite + tobermorite) precipitation. Ion exchange reactions were found to have little effect on pH. Alternative data for the kinetic dissolution of smectite produced no observable differences, and the adoption of a re

  13. [Can a laboratory investigation be called anything? "The NPU system" sorts out the concepts and gives systematic stringency].

    Science.gov (United States)

    Nordin, Gunnar; Klinteberg, Barbro; Persson, Birgitta; Forsum, Urban

    When communicating results from laboratory investigations from the laboratory to the requesters and further between different information systems, it is important that the value as well as the unique identity and name of the laboratory investigation are correctly cited. A committee under the International Federation for Clinical Chemistry and Laboratory Medicine (IFCC) and International Union for Pure and Applied Chemistry (IUPAC) has developed a systematic nomenclature for the correct classification of laboratory investigations. Each generic laboratory investigation is provided with a unique NPU code. The system is in use among approximately 30 different clinical laboratories in Sweden, and has capacity to be the common denominator of all laboratory investigations, and to be used as the identifier in various information systems. The NPU system for the Swedish laboratories is currently administered by EQUALIS and partly financed by the participating laboratories. Other ways of funding, of benefit for the whole health care sector, will be investigated. PMID:15921106

  14. Experimental Investigation of Aerodynamic Instability of Iced Bridge Cable Sections

    DEFF Research Database (Denmark)

    Koss, Holger; Lund, Mia Schou MØller

    2013-01-01

    The accretion of ice on structural bridge cables changes the aerodynamic conditions of the surface and influences hence the acting wind load process. Full-scale monitoring indicates that light precipitation at moderate low temperatures between zero and -5°C may lead to large amplitude vibrations of bridge cables under wind action. This paper describes the experimental simulation of ice accretion on a real bridge cable sheet HDPE tube segment (diameter 160mm) and its effect on the aerodynamic load. Furthermore, aerodynamic instability will be estimated with quasi-steady theory using the determined load coefficients and experimental simulation on a 1DOF elastically suspended cable section.

  15. Confined granular flow in silos experimental and numerical investigations

    CERN Document Server

    Tejchman, Jacek

    2013-01-01

      During confined flow of bulk solids in silos some characteristic phenomena can be created, such as: —         sudden and significant increase of wall stresses, —         different flow patterns, —         formation and propagation of wall and interior shear zones, —         fluctuation of pressures and, —         strong autogenous dynamic effects. These phenomena have not been described or explained in detail yet. The main intention of the experimental and theoretical research presented in this book is to explain the above mentioned phenomena in granular bulk solids and to describe them with numerical FE models verified by experimental results.

  16. Experimental and numerical investigation of liquid-metal free-surface flows in spallation targets

    International Nuclear Information System (INIS)

    Highlights: • Experimental study of free surface for lead bismuth eutectic target. • Numerical investigation of free surface of a liquid metal target. • Advanced free surface modelling. - Abstract: Accelerator Driven Systems (ADS) are extensively investigated for the transmutation of high-level nuclear waste within many worldwide research programs. The first advanced design of an ADS system is currently developed in SCK• CEN, Mol, Belgium: the Multi-purpose hYbrid Research Reactor for High-tech Applications (MYRRHA). Many European research programs support the design of MYRRHA. In the framework of the Euratom project ‘Thermal Hydraulics of Innovative nuclear Systems (THINS)’ a liquid-metal free-surface experiment is performed at the Karlsruhe Liquid Metal Laboratory (KALLA) of Karlsruhe Institute of Technology (KIT). The experiment investigates a full-scale model of the concentric free-surface spallation target of MYRRHA using Lead Bismuth Eutectic (LBE) as coolant. In parallel, numerical free surface models are developed and tested which are reviewed in the article. A volume-of-fluid method, a moving mesh model, a free surface model combining the Level-Set method with Large-Eddy Simulation model and a smoothed-particle hydrodynamics approach are investigated. Verification of the tested models is based on the experimental results obtained within the THINS project and on previous water experiments performed at the University Catholic de Louvain (UCL) within the Euratom project ‘EUROpean Research Programme for the TRANSmutation of High Level Nuclear Waste in Accelerator Driven System (EUROTRANS)’. The design of the target enables a high fluid velocity and a stable surface at the beam entry. The purpose of this paper is to present an overview of both experimental and numerical results obtained for free surface target characterization. Without entering in technical details, the status, the major achievements and lessons for the future with respect to model development are described as well as some applications, which were carried out within the work package ‘multi-phase flow’ of THINS

  17. Inquiry-based Investigation in Biology Laboratories: Does Neem Provide Bioprotection against Bean Beetles?

    Science.gov (United States)

    Pearce, Amy R.; Sale, Amanda Lovelace; Srivatsan, Malathi; Beck, Christopher W.; Blumer, Lawrence S.; Grippo, Anne A.

    2013-01-01

    We developed an inquiry-based biology laboratory exercise in which undergraduate students designed experiments addressing whether material from the neem tree ("Azadirachta indica") altered bean beetle ("Callosobruchus maculatus") movements and oviposition. Students were introduced to the bean beetle life cycle, experimental…

  18. Horonobe Underground Research Laboratory project. Investigation report for the 2006 fiscal year

    International Nuclear Information System (INIS)

    The Horonobe Underground Research Laboratory is planned to extend over a period of 20 years. The investigations will be conducted in three phases, namely 'Phase 1: Surface-based investigations', 'Phase 2: Construction Phase' (investigations during construction of the underground facilities) and 'Phase 3: Operation phase' (research in the underground facilities). This report summarizes the results of the investigations for the 2006 fiscal year (2006/2007), the second year of the Phase 2 investigations. The investigations, which are composed of 'Geoscientific research' and 'R and D on the geological disposal of high-level radioactive waste (HLW)', were carried out according to 'Horonobe Underground Research Laboratory Project Investigation Program for the 2006 Fiscal Year'. The results of these investigations, along with the results which were obtained in other departments of Japan Atomic Energy Agency (JAEA), are properly offered to the implementations and the safety regulations. JAEA proceeded with the project in, collaboration with experts from domestic and overseas research organisation. (author)

  19. Laboratory experiments investigating magnetic field production via the Weibel instability in interpenetrating plasma flows

    Science.gov (United States)

    Huntington, Channing; Fiuza, Frederico; Ross, James Steven; Zylstra, Alex; Pollock, Brad; Drake, R. Paul; Froula, Dustin; Gregori, Gianluca; Kugland, Nathan; Kuranz, Carolyn; Levy, Matthew; Li, Chikang; Meinecke, Jena; Petrasso, Richard; Remington, Bruce; Ryutov, Dmitri; Sakawa, Youichi; Spitkovsky, Anatoly; Takabe, Hideke; Turnbull, David; Park, Hye-Sook

    2015-08-01

    Astrophysical collisionless shocks are often associated with the presence of strong magnetic fields in a plasma flow. The magnetic fields required for shock formation may either be initially present, for example in supernova remnants or young galaxies, or they may be self-generated in systems such as gamma-ray bursts (GRBs). In the case of GRB outflows, the intense magnetic fields are greater than those seeded by the GRB progenitor or produced by misaligned density and temperature gradients in the plasma flow (the Biermann-battery effect). The Weibel instability is one candidate mechanism for the generation of sufficiently strong fields to create a collisionless shock. Despite their crucial role in astrophysical systems, observation of the magnetic fields produced by Weibel instabilities in experiments has been challenging. Using a proton probe to directly image electromagnetic fields, we present evidence of Weibel-generated magnetic fields that grow in opposing, initially unmagnetized plasma flows from laser-driven laboratory experiments. Three-dimensional particle-in-cell simulations reveal that the instability efficiently extracts energy from the plasma flows, and that the self-generated magnetic energy reaches a few percent of the total energy in the system. This result demonstrates an experimental platform suitable for the investigation of a wide range of astrophysical phenomena, including collisionless shock formation in supernova remnants, large-scale magnetic field amplification, and the radiation signature from gamma-ray bursts.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  20. The Role of Diffusive Hillslopes in Landscape Evolution: An Experimental Investigation

    Science.gov (United States)

    Sweeney, K. E.; Roering, J. J.; Ellis, C.; Singh, A.

    2014-12-01

    The competition between diffusive sediment transport on hillslopes and advective transport in valleys sets fundamental spatial and temporal landscape scales, including ridge-valley spacing and landscape response time. However, the interactions between hillslopes and channels are difficult to measure in natural landscapes, due to long timescales and confounding climatic and lithologic factors. Laboratory experiments allow us to observe complex sediment dynamics in a controlled setting, but past work on erosive landscapes does not include diffusive hillslopes and hence cannot provide insight into channel-hillslope interactions. Here, we present the first results from a novel laboratory experiment combining hillslope diffusion and valley advection. Our experimental apparatus, the eXperimental Landscape Modeling (XLM) facility at the St. Anthony Falls Laboratory, consists of a 0.5 m x 0.5 m test flume filled with crystalline silica (D50 = 30?) mixed with water, a high-resolution laser scanner to measure topography, and a series of load cells to measure sediment flux. Baselevel lowering is simulated by dropping two motorized weirs. During each run, we alternated between: (1) advective transport induced by a series of misting nozzles, where drops are not large enough to disturb sediment on impact, and (2) diffusive rainsplash transport driven by a constant head drip tray. We report a series of experiments where the relative strength of advection and diffusion are varied systematically between runs, testing theoretical predictions that dominantly diffusive landscapes will have larger ridge-valley spacing and respond more slowly to perturbations in baselevel. Our work provides an invaluable dataset for both testing numerical models of landscape evolution and guiding field investigations of channel-hillslope interactions.

  1. Experimental investigations of the dipolar interactions between single Rydberg atoms

    CERN Document Server

    Browaeys, Antoine; Lahaye, Thierry

    2016-01-01

    This review summarizes experimental works performed over the last decade by several groups on the manipulation of a few individual interacting Rydberg atoms. These studies establish arrays of single Rydberg atoms as a promising platform for quantum state engineering, with potential applications to quantum metrology, quantum simulation and quantum information.

  2. Valorization of rehydrated Deglet-Nour dates by an experimental investigation of solar drying processing method

    International Nuclear Information System (INIS)

    Highlights: • A laboratory scale direct solar dryer was constructed and investigated. • The solar drying of hard date palm fruits, Deglet-Nour variety, was studied. • Three improvements in the dryer operating modes were proposed and compared. • Combination drying mode has been selected as the most adequate process. • Selected mode ensures a high quality of product and allows short duration of treatment. - Abstract: In objective to valorize hard Deglet-Nour dates, a new postharvest processing method was proposed and investigated using a laboratory scale direct solar dryer. Date samples were soaked in distilled water then dried by solar drying mean. In order to improve the quality and consumer acceptance of this date variety, three proposed drying enhancements: drying under shade (DUS), drying with photovoltaic powered ventilation (DSV) and combination drying mode (DCM) were tested and compared with the basis case of natural ventilation drying (DNV). The obtained experimental results classified the drying with solar ventilation drying mode (DSV) and combination drying mode (DCM) in favorable operating conditions needed for the studied case. Measured air drying temperatures ranged between 41.8 and 56.0 °C and 39.3 and 51.2 °C respectively for the two above techniques. The drying duration to obtain the standard moisture content (0.35 kg/kg DM) was respectively 5.25 and 8 h. Regarding quality criteria and processing time, the combination drying mode was selected as the most adequate process

  3. Experimental investigations of void dynamics in a dusty discharge

    International Nuclear Information System (INIS)

    The first electrical and spectroscopic characterizations of an instability, usually called the 'heartbeat' instability, occurring in a laboratory dusty plasma are reported. The heartbeat instability consists of successive contractions and expansions of the central dust free region observed in a dense cloud of dust particles. This cloud is formed in a radio-frequency plasma by sputtering polymer material deposited on the electrodes. The evolution of the discharge current reveals the relatively complex shape of the instability and allows one to measure its evolution as a function of gas pressure and radio-frequency power

  4. Experimental Investigation of Two-Phase Flow in Rock Salt

    Energy Technology Data Exchange (ETDEWEB)

    Malama, Bwalya; Howard, Clifford L.

    2014-07-01

    This Test Plan describes procedures for conducting laboratory scale flow tests on intact, damaged, crushed, and consolidated crushed salt to measure the capillary pressure and relative permeability functions. The primary focus of the tests will be on samples of bedded geologic salt from the WIPP underground. However, the tests described herein are directly applicable to domal salt. Samples being tested will be confined by a range of triaxial stress states ranging from atmospheric pressure up to those approximating lithostatic. Initially these tests will be conducted at room temperature, but testing procedures and equipment will be evaluated to determine adaptability to conducting similar tests under elevated temperatures.

  5. Experimental investigation of radiative thermal rectifier using vanadium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Kota, E-mail: kotaito@mosk.tytlabs.co.jp [Toyota Central Research and Development Labs, Nagakute, Aichi 480-1192 (Japan); Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8904 (Japan); Nishikawa, Kazutaka; Iizuka, Hideo [Toyota Central Research and Development Labs, Nagakute, Aichi 480-1192 (Japan); Toshiyoshi, Hiroshi [Research Center for Advanced Science and Technology (RCAST), The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8904 (Japan)

    2014-12-22

    Vanadium dioxide (VO{sub 2}) exhibits a phase-change behavior from the insulating state to the metallic state around 340?K. By using this effect, we experimentally demonstrate a radiative thermal rectifier in the far-field regime with a thin film VO{sub 2} deposited on the silicon wafer. A rectification contrast ratio as large as two is accurately obtained by utilizing a one-dimensional steady-state heat flux measurement system. We develop a theoretical model of the thermal rectifier with optical responses of the materials retrieved from the measured mid-infrared reflection spectra, which is cross-checked with experimentally measured heat flux. Furthermore, we tune the operating temperatures by doping the VO{sub 2} film with tungsten (W). These results open up prospects in the fields of thermal management and thermal information processing.

  6. Experimental and theoretical investigation of innovative broadband microwave devices

    Science.gov (United States)

    1991-05-01

    The general scope of the work performed under this contract was quite broad and included both theoretical and experimental work related to the general problem of microwave and millimeter wave sources. The principal concepts which were of interest at the outset of the contract were the Two-Stream-Amplifier and the Cerenkov Maser. However, general theory and simulation of the Ubitron/Free-Electron Laser was also performed along with specific theoretical support for the Ubitron development program in the Vacuum Electronics Branch. In addition, a great deal of interest developed in the application of Field-Emission Arrays to RF source technology, and the experimental phase of the program shifted to encompass testing, design, and evaluation of several different approaches of this technology. The remainder of this report is devoted to a specific discussion of each phase of the program.

  7. Mathematical modelling and experimental investigation of tropical fruits drying

    Energy Technology Data Exchange (ETDEWEB)

    Karim, Md Azharul [Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, University of Melbourne, Melbourne VIC 3010 (Australia); Hawlader, M.N.A. [Department of Mechanical and Manufacturing Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore)

    2005-11-01

    A mathematical model has been developed to solve the heat and mass transfer equations for convective drying of tropical fruits. The model takes into account shrinkage of material and moisture content and shrinkage dependant effective diffusivity. Heat and mass transfer equations for the dryer, termed as equipment model, have also been developed to determine the changes of drying potential of the drying medium during drying. The material model is capable of predicting the instantaneous temperature and moisture distribution inside the material. The equipment model, on the other hand, describes the transfer process in the tunnel dryer and predicts the instantaneous temperature and humidity ratio of air at any location of the tunnel. Thus, the model is capable of predicting the dynamic behaviour of the dryer. The predicted results were compared with experimental data for the drying of banana slices dried in a solar dryer. Experimental results validated the model developed. (author)

  8. Experimental and Computational Investigations of Flow past Spinning Cylinders

    Science.gov (United States)

    Carlucci, Pasquale; Mehmedagic, Igbal; Buckley, Liam; Carlucci, Donald; Thangam, Siva

    2011-11-01

    Experiments are performed in a low speed subsonic wind tunnel to analyze flow past spinning cylinders. The sting-mounted cylinders are oriented such that their axis of rotation is aligned with the mean flow. Data from spinning cylinders with both rear-mounted and fore-mounted stings are presented for a Reynolds numbers of up to 260000 and rotation numbers of up to 1.2 (based on cylinder diameter). Computations are performed using a two-equation turbulence model that is capable of capturing the effects of swirl and curvature. The model performance was validated with benchmark experimental flows and implemented for analyzing the flow configuration used in the experimental study. The results are analyzed and the predictive capability of the model is discussed. Funded in part by U. S. Army, ARDEC.

  9. Experimental investigation and modeling of scale effects in jet ejectors

    Science.gov (United States)

    Gardner, W. G.; Wang, I.; Jaworski, J. W.; Brikner, N. A.; Protz, J. M.

    2010-08-01

    Three microscale jet ejectors were designed and tested to induce a suction draft using a supersonic micronozzle. Each axisymmetric nozzle was fabricated using three-dimensional electro-discharge machining to create throat diameters of 64, 187 and 733 µm with design expansion ratios of 2.5:1 and design ejector area ratios of 8. The experimental data using nitrogen gas for the motive fluid indicate that the ejector can produce a sufficient suction draft to enable its substitution for high-speed turbomachinery in micro engine applications. A pumping power density of 308 kW L-1 is observed experimentally, which agrees well with a theoretical model including losses associated with the suction flow inlet and viscous effects in the motive nozzle and mixing regions. The present theoretical model further predicts a maximum achievable power density of 1 MW L-1 for microscale ejectors with a throat diameter of 10 µm and throat Reynolds number of 1300.

  10. Experimental investigation and modeling of scale effects in jet ejectors

    International Nuclear Information System (INIS)

    Three microscale jet ejectors were designed and tested to induce a suction draft using a supersonic micronozzle. Each axisymmetric nozzle was fabricated using three-dimensional electro-discharge machining to create throat diameters of 64, 187 and 733 µm with design expansion ratios of 2.5:1 and design ejector area ratios of 8. The experimental data using nitrogen gas for the motive fluid indicate that the ejector can produce a sufficient suction draft to enable its substitution for high-speed turbomachinery in micro engine applications. A pumping power density of 308 kW L?1 is observed experimentally, which agrees well with a theoretical model including losses associated with the suction flow inlet and viscous effects in the motive nozzle and mixing regions. The present theoretical model further predicts a maximum achievable power density of 1 MW L?1 for microscale ejectors with a throat diameter of 10 µm and throat Reynolds number of 1300.

  11. Facts and Figuring: An Experimental Investigation of Network Structure and Performance in Information and Solution Spaces

    CERN Document Server

    Shore, Jesse; Lazer, David

    2014-01-01

    Using data from a large laboratory experiment on problem solving in which we varied the structure of 16-person networks we investigate how an organization's network structure may be constructed to optimize performance in complex problem-solving tasks. Problem solving involves both search for information and search for theories to make sense of that information. We show that the effect of network structure is opposite for these two equally important forms of search. Dense clustering encourages members of a network to generate more diverse information, but it also has the power to discourage the generation of diverse theories: clustering promotes exploration in information space, but decreases exploration in solution space. Previous research, tending to focus on only one of those two spaces, had produced inconsistent conclusions about the value of network clustering. By adopting an experimental platform on which information was measured separately from solutions, we were able to reconcile past contradictions an...

  12. Horonobe Underground Research Laboratory project. Investigation report for the 2011 fiscal year

    International Nuclear Information System (INIS)

    The Horonobe Underground Research Laboratory Project is planned to extend over a period 20 years. The investigations will be conducted in three phases, namely “Phase 1: Surface-based investigations”, “Phase 2: Construction Phase” (investigations during construction of the underground facilities) and “Phase 3: Operation phase” (research in the underground facilities). This report summarizes the results of the investigations for the 2011 fiscal year (2011/2012). The investigations, which are composed of “Geoscientific research” and “R and D on geological disposal technology”, were carried out according to “Horonobe Underground Research Laboratory Project Investigation Program for the 2011 Fiscal year”. The results of these investigations, along with the results which were obtained in other departments of Japan Atomic Energy Agency (JAEA), are properly offered to the implementations and the safety regulations. For the sake of this, JAEA has proceeded with the project in collaboration with experts from domestic and overseas research organisations. (author)

  13. Horonobe Underground Research Laboratory project. Investigation report for the 2012 fiscal year

    International Nuclear Information System (INIS)

    The Horonobe Underground Research Laboratory Project is planned to extend over a period 20 years. The investigations will be conducted in three phases, namely 'Phase 1: Surface-based investigations', 'Phase 2: Construction Phase' (investigations during construction of the underground facilities) and 'Phase 3: Operation phase' (research in the underground facilities). This report summarizes the results of the investigations for the 2012 fiscal year (2012/2013). The investigations, which are composed of 'Geoscientific research' and R and D on geological disposal technology', were carried out according to 'Horonobe Underground Research Laboratory Project Investigation Program for the 2012 Fiscal year'. The results of these investigations, along with the results which were obtained in other departments of Japan Atomic Energy Agency (JAEA), are properly offered to the implementations and the safety regulations. For the sake of this, JAEA has proceeded with the project in collaboration with experts from domestic and overseas research organisations. (author)

  14. Horonobe Underground Research Laboratory project. Investigation report for the 2010 fiscal year

    International Nuclear Information System (INIS)

    The Horonobe Underground Research Laboratory Project is planned to extend over a period 20 years. The investigations will be conducted in three phases, namely 'Phase 1: Surface-based investigations', 'Phase 2: Construction Phase' (investigations during construction of the underground facilities) and 'Phase 3: Operation phase' (research in the underground facilities). This report summarizes the results of the investigations for the 2010 fiscal year (2010/2011). The investigations, which are composed of 'Geoscientific research' and 'R and D on geological disposal technology', were carried out according to 'Horonobe Underground Research Laboratory Project Investigation Program for the 2010 Fiscal year'. The results of these investigations, along with the results which were obtained in other departments of Japan Atomic Energy Agency (JAEA), are properly offered to the implementations and the safety regulations. For the sake of this, JAEA has proceeded with the project in collaboration with experts from domestic and overseas research organisations. (author)

  15. Investigations in Experimental and Theoretical High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Krennrich, Frank [Iowa State University

    2013-07-29

    We report on the work done under DOE grant DE-FG02-01ER41155. The experimental tasks have ongoing efforts at CERN (ATLAS), the Whipple observatory (VERITAS) and R&D work on dual readout calorimetry and neutrino-less double beta decay. The theoretical task emphasizes the weak interaction and in particular CP violation and neutrino physics. The detailed descriptions of the final report on each project are given under the appropriate task section of this report.

  16. Experimental Investigation of Trapped Sine-Gordon Solitons

    DEFF Research Database (Denmark)

    Davidson, A.; Dueholm, B.; Kryger, B.; Pedersen, Niels Falsig

    1985-01-01

    We have observed for the first time a single sine-Gordon soliton trapped in an annular Josephson junction. This system offers a unique possibility to study undisturbed soliton motion. In the context of perturbation theory, the soliton may be viewed as a relativistic particle moving under a uniform force with damping. Accordingly our experimental results are displayed directly in a force-versus-momentum plane, where they may be described by a theoretically derived universal curve.

  17. Precise Experimental Investigation of Eigenmodes in a Planar Ion Crystal

    OpenAIRE

    Kaufmann H.; Ulm S.; Jacob G; Poschinger U.; Landa H.; Retzker A.; Plenio M.B.; Schmidt-Kaler F.

    2012-01-01

    The accurate characterization of eigenmodes and eigenfrequencies of two-dimensional ion crystals provides the foundation for the use of such structures for quantum simulation purposes. We present a combined experimental and theoretical study of two-dimensional ion crystals. We demonstrate that standard pseudopotential theory accurately predicts the positions of the ions and the location of structural transitions between different crystal configurations. However, pseudopotential theory is insu...

  18. Experimental investigation of the 61?+ ‘shelf' state of KCs

    Science.gov (United States)

    Szczepkowski, J.; Grochola, A.; Jastrzebski, W.; Kowalczyk, P.

    2014-10-01

    We report the first experimental observation of the 61?+ state in the KCs molecule. Polarization labelling spectroscopy technique was applied to determine energies of about 1000 rovibrational levels in this state, most of them strongly perturbed by the neighbouring 43? state levels. The inverted perturbation approach was used to construct the irregular potential energy curve of the 61?+ state. It is compared with the recent theoretical calculations to show that Hund's coupling case (a) is proper for description of this state.

  19. Experimental Performance Investigation of Digital Beamforming on Synthetic Aperture Radar

    OpenAIRE

    Kim, Junghyo; Younis, Marwan; Wiesbeck, Werner

    2008-01-01

    In this paper, we present the experimental results of a Digital Beam Forming (DBF) Synthetic Aperture Radar (SAR) performance on the purpose of the High- Resolution Wide-Swath (HRWS) SAR concept. A ground-based SAR system successfully demonstrated the DBF SAR operation. The demonstrator acquired SAR raw data with very dense spatial sampling rate in order to obtain various sampling rates. We evaluate DBF performance with respect to the image quality factor with two d...

  20. Experimental investigation of dynamic pressure loads during dam break

    Science.gov (United States)

    Lobovský, L.; Botia-Vera, E.; Castellana, F.; Mas-Soler, J.; Souto-Iglesias, A.

    2014-07-01

    The objectives of this work are to revisit the experimental measurements on dam break flow over a dry horizontal bed and to provide a detailed insight into the dynamics of the dam break wave impacting a vertical wall downstream the dam, with emphasis on the pressure loads. The measured data are statistically analyzed and critically discussed. As a result, an extensive set of data for validation of computational tools is provided.

  1. Experimental investigation of dynamic pressure loads during dam break

    OpenAIRE

    Lobovský, L.; Botia Vera, Elkin; Castellana, Filippo; Mas Soler, Jordi; Souto Iglesias, Antonio

    2013-01-01

    The objectives of this work are to revisit the experimental measurements on dam break flow over a dry horizontal bed and to provide a detailed insight into the dynamics of the dam break wave impacting a vertical wall downstream the dam, with emphasis on the pressure loads. The measured data are statistically analyzed and critically discussed. As a result, an extensive set of data for validation of computational tools is provided.

  2. Experimental investigation of coarse particle conveying in pipes.

    Czech Academy of Sciences Publication Activity Database

    Vlasák, Pavel; Chára, Zden?k; Konfršt, Ji?í; Krupi?ka, Jan

    Vol. 92. Les Ulis : EDP Sciences, 2015 - (Dan?ová, P.; Vít, T.), 02111-p.1-02111-p.8 ISSN 2100-014X. [Experimental Fluid Mechanics 2014. ?eský Krumlov (CZ), 18.11.2014-21.11.2014] R&D Projects: GA ?R GAP105/10/1574 Institutional support: RVO:67985874 Keywords : particles motion * mixture flow behaviour * coarse particles Subject RIV: BK - Fluid Dynamics

  3. Experimental investigation of pulsed entangled photons and photonic quantum channels

    OpenAIRE

    Nambu, Yoshihiro; Usami, Koji; Tomita, Akihisa; Ishizaka, Satoshi; Hiroshima, Tohya; Tsuda, Yoshiyuki; matsumoto, Keiji; Nakamura, Kazuo

    2002-01-01

    The development of key devices and systems in quantum information technology, such as entangled particle sources, quantum gates and quantum cryptographic systems, requires a reliable and well-established method for characterizing how well the devices or systems work. We report our recent work on experimental characterization of pulsed entangled photonic states and photonic quantum channels, using the methods of state and process tomography. By using state tomography, we coul...

  4. Final Report: Experimental Investigation of Nonlinear Plasma Wake-Fields

    International Nuclear Information System (INIS)

    We discuss the exploration of the newly proposed blowout regime of the plasma wakefield accelerator and advanced photoinjector technology for linear collider applications. The plasma wakefield experiment at ANL produced several ground-breaking results in the physics of the blowout regime. The photoinjector R and D effort produced breakthroughs in theoretical, computational, and experimental methods in high brightness beam physics. Results have been published

  5. Experimental investigations on longitudinal dispersive mixing in heterogeneous aquifers

    OpenAIRE

    Jose, Surabhin Chackiath

    2005-01-01

    Reactive mixing of compounds in porous media is a topic of current research interest because accurate estimation of reaction rates are crucial in planning aquifer remediation methods. It is suggested that relative parameters for dilution are better quantities to estimate reaction rates than the generally used classical macrodispersion coefficients. Most of the concepts developed in the field of reactive mixing are based on theoretical and numerical studies, and have not been experimentally te...

  6. Experimental investigation of unstrained diffusion flames and their instabilities

    OpenAIRE

    Robert, Etienne

    2009-01-01

    In this thesis, thermal-diffusive instabilities are studied experimentally in diffusion flames. The novel species injector of a recently developed research burner, consisting of an array of hypodermic needles, which allows to produce quasi one-dimensional unstrained diffusion flames has been improved. It is used in a new symmetric design with fuel and oxidizer injected through needle arrays which allows to independently choose both the magnitude and direction of the bulk flow through the flam...

  7. Experimental investigation on creep behaviour of an epoxy adhesive

    OpenAIRE

    Silva, Patrícia Moreira; Sena-Cruz, José; AZENHA, Miguel; Escusa, Gonçalo Gomes

    2015-01-01

    Epoxy adhesives have been extensively used in structural strengthening. This leads to a great concern in assessing their long-term performance since epoxy resins present viscoelastic behaviour. This work aims to better understand the long-term behaviour of a specific epoxy adhesive due to the creep effects. Therefore, an experimental program comprising tensile creep tests was carried out, divided in two series: (i) series S1 - epoxy specimens subjected to different stress levels for a predefi...

  8. Combined Experimental-Numerical Method for Investigation of Ductile Metals.

    Czech Academy of Sciences Publication Activity Database

    Valach, Jaroslav; Ž?árský, M.; Jahoda, J.

    Wuppertal : Institute static and dynamic of structures Bergischen Universitat Wuppertal, 2010 - (Harte, R.), s. 62-63 ISBN N. [Bilateral Czech/German Symposium /12./. Bremen (DE), 30.06.2010-03.07.2010] R&D Projects: GA ?R(CZ) GA103/09/2101 Institutional research plan: CEZ:AV0Z20710524 Keywords : hybrid experimental-numerical method * ductility * deformation Subject RIV: JL - Materials Fatigue, Friction Mechanics

  9. Manufacturing and experimental investigation of green composite materials

    OpenAIRE

    ????????????????, ?????????

    2013-01-01

    The aim of the present thesis is to explore sustainable low cost environmentally friendly composite materials. It is a step by step experimental research. Firstly, taking under consideration the so far commercial available non-organic materials used as reinforcement and the petroleum based resins used as matrices, composite materials were fabricated and mechanically characterized. Different components in micro- and nano- scale were combined. Afterwards, the non-organic materials used a...

  10. Experimental investigation of ship-bank interaction forces

    OpenAIRE

    Vantorre, M.; Delefortrie, G.; Eloot, K.; LAFORCE, E

    2008-01-01

    A review of literature on ship-bank interaction is given, with the emphasis on experimental data and empirical formulae. The results of a systematic captive model test program carried out in the Towing Tank for Manoeuvres in Shallow Water (co-operation Flanders Hydraulics - Ghent University) in Antwerp (Belgium) arc used for discussing the influence of the main parameters determining the hydrodynamic forces and moments. The test series were carried out with three ship models in parallel cours...

  11. Experimental investigation into infrasonic emissions from atmospheric turbulence.

    Science.gov (United States)

    Shams, Qamar A; Zuckerwar, Allan J; Burkett, Cecil G; Weistroffer, George R; Hugo, Derek R

    2013-03-01

    Clear air turbulence (CAT) is the leading cause of in-flight injuries and in severe cases can result in fatalities. The purpose of this work is to design and develop an infrasonic array network for early warning of clear air turbulence. The infrasonic system consists of an infrasonic three-microphone array, compact windscreens, and data management system. Past experimental efforts to detect acoustic emissions from CAT have been limited. An array of three infrasonic microphones, operating in the field at NASA Langley Research Center, on several occasions received signals interpreted as infrasonic emissions from CAT. Following comparison with current lidar and other past methods, the principle of operation, the experimental methods, and experimental data are presented for case studies and confirmed by pilot reports. The power spectral density of the received signals was found to fit a power law having an exponent of -6 to -7, which is found to be characteristics of infrasonic emissions from CAT, in contrast to findings of the past. PMID:23464000

  12. Study on clinical and laboratory diagnostic of Lyme disease in dogs after experimental infection

    Directory of Open Access Journals (Sweden)

    Savi? Sara

    2012-01-01

    Full Text Available Experimental infection was done on 13 dogs, with B. burgdorferi s.l., in the epitzootiological area where Lyme disease in dogs and humans is present. Prior to the experimental infection, dogs in the experiment had no contact with B. burgdorferi, and they were kept in isolation. Serological methods used in the study were complement fixation and ELISA test. Biochemical blood analysis was done, also. The experimental infection of dogs was done with a referent ATCC B. burgdorferi s.l. culture, and with the isolates of B. burgdorferi s.l. previousely gained from Ixodes ricinus ticks collected on selected locations of the observed region in the northern part of Serbia (Vojvodina province. After the experimental infection, clinical symptoms were not seen in dogs and positive serological results were found in 70% of experimentally infected dogs. Immunodiagnostic criteria for the diagnosis of Lyme disease in dogs are established. In dogs without clinical symptoms for Lyme disease, when clarifying the laboratory results, one must have in mind the epizootiological situation of the region and also the possibility of former contact of the dog with B. burgdorferi s.l. For epizootiological surveys, CF can be used as an approximate screening method, with obligatory conformation with ELISA in the case of positive findings.

  13. Using experimental design modules for process characterization in manufacturing/materials processes laboratories

    Science.gov (United States)

    Ankenman, Bruce; Ermer, Donald; Clum, James A.

    1994-01-01

    Modules dealing with statistical experimental design (SED), process modeling and improvement, and response surface methods have been developed and tested in two laboratory courses. One course was a manufacturing processes course in Mechanical Engineering and the other course was a materials processing course in Materials Science and Engineering. Each module is used as an 'experiment' in the course with the intent that subsequent course experiments will use SED methods for analysis and interpretation of data. Evaluation of the modules' effectiveness has been done by both survey questionnaires and inclusion of the module methodology in course examination questions. Results of the evaluation have been very positive. Those evaluation results and details of the modules' content and implementation are presented. The modules represent an important component for updating laboratory instruction and to provide training in quality for improved engineering practice.

  14. Experimental and numerical investigation of hydro power generator ventilation

    Science.gov (United States)

    Jamshidi, H.; Nilsson, H.; Chernoray, V.

    2014-03-01

    Improvements in ventilation and cooling offer means to run hydro power generators at higher power output and at varying operating conditions. The electromagnetic, frictional and windage losses generate heat. The heat is removed by an air flow that is driven by fans and/or the rotor itself. The air flow goes through ventilation channels in the stator, to limit the electrical insulation temperatures. The temperature should be kept limited and uniform in both time and space, avoiding thermal stresses and hot-spots. For that purpose it is important that the flow of cooling air is distributed uniformly, and that flow separation and recirculation are minimized. Improvements of the air flow properties also lead to an improvement of the overall efficiency of the machine. A significant part of the windage losses occurs at the entrance of the stator ventilation channels, where the air flow turns abruptly from tangential to radial. The present work focuses exclusively on the air flow inside a generator model, and in particular on the flow inside the stator channels. The generator model design of the present work is based on a real generator that was previously studied. The model is manufactured taking into consideration the needs of both the experimental and numerical methodologies. Computational Fluid Dynamics (CFD) results have been used in the process of designing the experimental setup. The rotor and stator are manufactured using rapid-prototyping and plexi-glass, yielding a high geometrical accuracy, and optical experimental access. A special inlet section is designed for accurate air flow rate and inlet velocity profile measurements. The experimental measurements include Particle Image Velocimetry (PIV) and total pressure measurements inside the generator. The CFD simulations are performed based on the OpenFOAM CFD toolbox, and the steady-state frozen rotor approach. Specific studies are performed, on the effect of adding "pick-up" to spacers, and the effects of the inlet fan blades on the flow rate through the model. The CFD results capture the experimental flow details to a reasonable level of accuracy.

  15. Experimental and CFD investigation of gas phase freeboard combustion

    DEFF Research Database (Denmark)

    Andersen, Jimmy

    2009-01-01

    Reliable and accurate modeling capabilities for combustion systems are valuable tools for optimization of the combustion process. This work concerns primary precautions for reducing NO emissions, thereby abating the detrimental effects known as “acid rain”, and minimizing cost for flue gas treatment. The aim of this project is to provide validation data for Computational Fluid Dynamic (CFD) models relevant for grate firing combustion conditions. CFD modeling is a mathematical tool capable of predicting fluid flow, mixing and chemical reaction with thermal conversion and transport. Prediction of pollutant formation, which occurs in small concentrations with little impact on the general combustion process is in this work predicted by a post-processing step, making it less computationally expensive. A reactor was constructed to simulate the conditions in the freeboard of a grate fired boiler, but under well-defined conditions. Comprehensive experimental data for velocity field, temperatures, and gas compositionare obtained from a 50 kW axisymmetric non-swirling natural gas fired combustion setup under two different settings. Ammonia is added to the combustion setup in order to simulate fuel-NO formation during grate firing biomass combustion conditions. The experimental results are in this work compared to CFD modeling. The modeling results show, that the CFD model captured the main features of the combustion process and flow patterns. The application of more advanced chemical reaction mechanisms does not improve the prediction of the overall combustion process, but do provide additional formation about species (especially H2 and radicals), which is desirable for post-processing pollutant formation. NO formation is post-processed using various ammonia oxidation schemes and different post-processing techniques. The results in some cases provide a reasonable agreement with the experimental data. In general the application of advanced combustion modeling and more advanced ammonia oxidation mechanisms does not improve the agreement with experimental data compared to the simple eddy dissipation (mixed is burned) approach with post processing of a global combustion mechanism. The experimental setup does however not serve as a perfect validation case. The Reynolds numbers in the system put the flow regime in the transitional region, where turbulence modeling is difficult. Furthermore, the inclined jets show an affinity towards wall attachment, the entire modeling result is very sensitive to the prediction of these jets.

  16. Experimental study of a laboratory stationary plasma thruster in the Pivoine French test facility

    Energy Technology Data Exchange (ETDEWEB)

    Perot, C.; Gascon, N.; Hauser, A.; Bechu, S.; Lasgorceix, P.; Dudeck, M. [Centre National de la Recherche Scientifique (CNRS), Lab. d' Aerothermique, 45 - Orleans-la-Source (France)

    1999-07-01

    During several years, CNES (French Space Agency) and SEP-division de SNECMA have appraised Russian electric propulsion technologies, which have the potential to increase the performance of Western spacecraft. They have been particularly interested in the Russian Hall thruster technology, called Stationary Plasma Thruster (SPT), which has several advantages: for a typical SPT100 (discharge chamber diameter of 100 mm), a specific impulse (thrust/propellant flow) of 1400-1500 s, an efficiency of 45-50%, a long lifetime (up to 7000 h) and a large number of on/off cycles. using this type of thruster for the orbit control of geostationary satellites leads to a great decrease in the launch mass or, for a fixed launch mass, to a great increase in the payload mass. Though the functioning principle of an SPT is simple, a lot of the physical processes that occur in this type of thruster are not yet fully understood. To contribute to the development of the researches on the physical processes of ion thruster and the design of the next generation of thrusters, a French Research Group 'Plasma Propulsion for Orbital Systems' has been created, a new test facility and a laboratory model Hall thruster have been manufactured. The laboratory thruster was tested in the new test facility for electric thrusters research, recently assembled at Orleans in the Laboratoire d'Aerothermique. The laboratory model experimental studies were conducted as part of a program to evaluate the operating characteristics of Stationary Plasma Thruster. This thruster, intended to serve to study the Hall thrusters, was operated at various values of the discharge voltage, propellant mass flow and coils current. Electrical properties were measured at various operating points. After the review of the experimental apparatus and the thruster, the results of the first set of operating characteristics measurements of the laboratory model thruster are summarised. (authors)

  17. Experimental Investigation of Use of Microsilica in Self Compacting Concrete

    Directory of Open Access Journals (Sweden)

    Mr.Ashok P. Kalbande

    2012-05-01

    Full Text Available This paper is described Project in detail and presents laboratory observation. Microsilica is used as a 10% replacement of cement by weight. Various test were conducted on fine aggregate & coarse aggregate, to determine specific gravity, bulk density, fineness modulus of aggregate, concrete mix proportion design using this parameter..For conventional concrete water cement ratio of 0.4 and for microsilica concrete is increased water contain about 20liter/m3. Water demand increases in proportion to the amount of microsilica added. Mixing the concrete and various test are conducted on fresh concrete i.e. Slump flow, V- Funnel, L-Box, U-Box and result are obtained. Using this concrete cube specimen are cast for testing different hardened properties of concrete. i.e. 3 Days, 7 Days, 14 Days, 28 Days Compressive strength of concrete.

  18. Sediment transport during flash flood events on an intermittent river: an experimental laboratory study.

    Science.gov (United States)

    Moustabachir, H.; Chahinian, N.; Romieux, N.; Vittenet, J.; Gayrard, E.; Tournoud, M. G.

    2009-04-01

    Flash floods have a number of impacts on the water quality of river systems because the later is the resultant of pollutant input into the river and its transformation along its course. In the case of intermittent rivers this impact is increased by the long drought periods that usually precede such floods. Indeed, the pollutants are known to accumulate in the dry river sediments during the drought period and are flushed away by the first floods. The Vène, a small experimental catchment (67 km²) located in southern France is a perfect example of this type of behavior. The field data collected on the catchment since 1994 through routine and flood monitoring clearly show an increase in suspended solids and nutrient concentrations during flash floods. However, the hydraulic conditions which lead to the triggering of sediment movement and re-suspension are not known. The aim of this study is to investigate sediment re-suspension mechanisms by reproducing the dynamics of sediment movement during flash floods at the reach scale in controlled laboratory conditions. A rectangular flume (6m*0.29m*0.18m) is used as a scale model of a 1 km reach. Variable flow conditions can be set in the flume through a quarter turn valve. Discharge values are monitored using an electromagnetic flow meter and water velocity measurements are carried out in the flume using a Pitot probe coupled to a digital manometer. Dynamic similarity is imposed between the reach and the flume i.e. the reach's Froude number is set equal to that of the flume. The reach's rating curve is used to determine a set of experimental height and flow values for the flume. For each test, the slope of the flume is modified in order to respect the rating curve. The flume's bed is reconstructed by respecting the similarity ratios determined previously using glass micro beads to represent its sediments. Various tests are carried out in steady-state conditions for different discharge values. In transient conditions, the observed hydrograph's rising times are used to calculate corresponding flow durations in the flume. The entire water column is sampled for sediment mass at the outlet of the flume using very fine time steps. The measured velocity gradients are used to calculate the corresponding shear stress values at the bottom of the water column. Relationships between discharge, rising time, shear stress, and sediment mass dynamics are analyzed. The preliminary results highlight the role of turbulent processes on sediment movement and re-suspension. However, the results are extremely sensitive to the sediment arrangement pattern i.e. to bed morphology. Although the Pitot probe has clear advantages in terms of ease of use and price, the corresponding measurements do not allow an accurate determination of shear stress values. The experimental protocol is currently being enhanced to solve this problem by seeking alternate measurement devices.

  19. The Origin of Mercury's Surface Composition, an Experimental Investigation

    Science.gov (United States)

    Boujibar, A.; Righter, K.; Rapp, J. F.; Ross, D. K.; Pando, K. M.; Danielson, L. R.; Fontaine, E.

    2016-01-01

    Introduction: Results from MESSENGER spacecraft have confirmed the reduced nature of Mercury, based on its high core/mantle ratio and its FeO-poor and S-rich surface. Moreover, high resolution images revealed large volcanic plains and abundant pyroclastic deposits, suggesting major melting stages of the Mercurian mantle. In addition, MESSENGER has provided the most precise data to date on major elemental compositions of Mercury's surface. These results revealed considerable chemical heterogeneities that suggested several stages of differentiation and re-melting processes. This interpretation was challenged by our experimental previous study, which showed a similar compositional variation in the melting products of enstatite chondrites, which are a possible Mercury analogue. However, these experimental melts were obtained over a limited range of pressure (1 bar to 1 gigapascal) and were not compared to the most recent elemental maps. Therefore, here we extend the experimental dataset to higher pressures and perform a more quantitative comparison with Mercury's surface compositions measured by MESSENGER. In particular, we test whether these chemical heterogeneities result from mixing between polybaric melts. Our experiments and models show that the majority of chemical diversity of Mercury's surface can result from melting of a primitive mantle compositionally similar to enstatite chondrites in composition at various depths and degrees of melting. The high-Mg region's composition is reproduced by melting at high pressure (3 gigapascals) (Tab. 1), which is consistent with previous interpretation as being a large degraded impact basin based on its low elevation and thin average crust. While low-Mg NVP (North Volcanic Plains) are the result of melting at low pressure (1 bar), intermediate-Mg NVP, Caloris Basin and Rachmaninoff result from mixing of a high-pressure (3 gigapascals) and low-pressure components (1 bar for Rachmaninoff and 1 gigapascal for the other regions) (Tab. 1). Moreover, all compositions suggest mixing between low and high degree melts that indicate important differentiation processes.

  20. Experimental investigation of heat losses at the PACTEL facility

    International Nuclear Information System (INIS)

    Some methods are described in the present study for determining heat losses of experimental test facilities. Two different methods were chosen to be applied for the PACTEL. The experiment based on the transient method was performed in June, 1990, while results of earlier natural circulation tests could serve as a comparison between two procedures. Calculated results and plots show that the formation and values of heat losses have come up to the expectations however additional experiment is needed to obtain information about the distribution of heat losses throughout the facility. (orig.). (4 refs., 17 figs., 1 tab.)

  1. Experimental Investigation of Tesla Turbine and its Underlying Theory

    OpenAIRE

    Kartikeya Awasthi; Aman Aggarwal

    2014-01-01

    Nikola Tesla is widely known for his outstanding achievements in generation transmission and utilization of power. The object of this paper is to experimentally verify one such method of extracting electrical power from fluid energy; devised by Tesla in his 1913 patent; known as Tesla Turbine. It is to be noted that almost no work has been done using water as the working fluid for the turbine so an attempt to reconstruct the turbine as per Nikola Tesla’s patent has been made with positive res...

  2. Experimental investigations on the four-loop test facility ROCOM

    International Nuclear Information System (INIS)

    For the analysis of the core behaviour during boron dilution transients and main steam line breaks, coupled neutron kinetic/thermal hydraulic codes are necessary. These codes must contain models of the coolant mixing on its way from the inlet nozzles to the core entrance, because the reactivity insertion strongly depends on the distribution of temperature and boron concentration at the core inlet. To model the coolant mixing the ROCOM test facility was built, a fluid dynamic 1:5 scaled model of the Konvoi reactor. The experimental results at steady state flow conditions are presented in a survey form. (orig.)

  3. Experimental Investigation on Thermoelectric Chiller Driven by Solar Cell

    OpenAIRE

    Yen-Lin Chen; Zi-Jie Chien; Wen-Shing Lee; Ching-Song Jwo; Kun-Ching Cho

    2014-01-01

    This paper presents experimental explorations on cooling performance of thermoelectric chillers being driven by solar cells, as well as comparison results to the performance being driven by fixed direct current. Solar energy is clear and limitless and can be collected by solar cells. We use solar cells to drive thermoelectric chillers, where the cold side is connected to the water tank. It is found that 250 mL of water can be cooled from 18.5°C to 13°C, where the corresponding coefficient of ...

  4. Experimental investigation of the transverse SBS excitation in anisotropic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Bel`kov, S.A.; Dolgopolov, Yu.V.; Kochemasov, G.G.; Kulikov, S.M.; Solov`eva, M.N.; Sukharev, S.A.; Voronich, I.N. [Russian Federal Nuclear Center, Arzamas (Russian Federation). Inst. of Experimental Physics

    1995-12-31

    One of the factors which should be taken into account in creating high-power broad-aperture neodymium laser facilities is the possibility of generating the backward and transverse stimulated Brillouin scattering(SBS) in optical elements of the facility. Here, transverse SBS characteristics of the KDP crystal were determined by the method of SBS generation excitation in the transverse resonator. Fused silica was utilized as the test medium. Experimental oscillograms of Stokes pulses were processed by the method of pulse form approximation using the four-parametric function of time.

  5. Experimental investigation of the transverse SBS excitation in anisotropic crystals

    International Nuclear Information System (INIS)

    One of the factors which should be taken into account in creating high-power broad-aperture neodymium laser facilities is the possibility of generating the backward and transverse stimulated Brillouin scattering(SBS) in optical elements of the facility. Here, transverse SBS characteristics of the KDP crystal were determined by the method of SBS generation excitation in the transverse resonator. Fused silica was utilized as the test medium. Experimental oscillograms of Stokes pulses were processed by the method of pulse form approximation using the four-parametric function of time

  6. An experimental investigation of Fang's Ag superlens suitable for integration

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Nielsen, Rasmus Bundgaard; Xiao, Sanshui; Mortensen, Asger; Boltasseva, Alexandra; Kristensen, Anders

    2009-01-01

    We report on experimental realization of the Fang Ag superlens structure [1] suitable for further processing and integration in bio-chips by replacing PMMA with a highly chemical resistant cyclo-olefin copolymer, mr-I T85 (Micro Resist Technology, Berlin, Germany). The superlens was able to resolve 80 nm half-pitch gratings when operating at a free space wavelength of 365 nm. Fang et al. used PMMA since it enables the presence of surface plasmons at the PMMA/Ag interface at 365 nm and because it...

  7. Impact performance of specimens subjected to fatigue loading - experimental investigation

    Science.gov (United States)

    Göringer, Jakub; Foglar, Marek; Ji?í?ek, Pavel

    2015-09-01

    The impact performance of reinforced concrete specimens subjected to fatigue loading has not been quantified properly yet. This topic is significant in the field of vehicle impact or similar applications. The paper aims to fill this gap by presenting the on-going experimental program. The paper presents outcomes of the experiments focused on the performance of RC beams subjected to drop-weight impact loading. The behaviour of the beams which were prior to the impact testing subjected to cyclic loading was compared to the behaviour of the beams which were not subjected to cyclic loading.

  8. The experimental investigation of bounce characteristics of ACV responsive skirt

    Science.gov (United States)

    Zhou, W. L.; Ma, T.

    This paper presents some experimental results on the bounce characteristics of the bag-finger responsive skirt and on skirt frequency response under cushion pressure excitation obtained in a large-scale box facility. The influence of some parameters on the amplitude and frequency of the skirt bounce motion and the amplitude of the cushion pressure oscillation were explored, and the corresponding bounce boundary curves are given. Some interesting nonlinear phenomena related to the skirt instability in the time domain response are presented. The mechanism for skirt bounce and the important parameters affecting skirt dynamic stability are examined, and some means for eliminating skirt bounce are introduced.

  9. Experimental investigation of engine jet/vortex interaction

    OpenAIRE

    Huppertz, G.

    2010-01-01

    Since the 1970s a main topic in vortex research is the problem of wake vortex hazard. This thesis focuses on the aspect of engine jet vortex interaction and discusses experimental results from low speed wind tunnel tests in the wake of a swept wing half model with a model engine that can be span wise moved during wind tunnel operation. The falsifying effect of vortex meandering or unsteady movement on the evaluation of wake vortex measurements using PIV technique is analysed by a numerical me...

  10. Experimental investigations on ejector refrigeration system with ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Sankarlal, T.; Mani, A. [Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India)

    2007-07-15

    A vapor ejector refrigeration system has been designed and developed to operate with ammonia. In this paper, performance of ejector refrigeration system has been experimentally studied with three different area ratio ejectors by varying operational parameters namely generator, condenser and evaporator temperatures. Effect of non-dimensional parameters like compression ratio, expansion ratio and area ratio on the system performance is studied. Entrainment ratio and coefficient of performance of the system increase with increase in ejector area ratio and expansion ratio and they increase with decrease in compression ratio. (author)

  11. Experimental and numerical investigation of gas phase freeboard combustion

    DEFF Research Database (Denmark)

    Andersen, Jimmy; Jensen, Peter Arendt; Hvid, S.L.; Glarborg, Peter

    2009-01-01

    modeling approaches, including global schemes and analytically reduced mechanisms, were tested in the CFD calculations. In addition, the simplified schemes were compared to reference calculations with a detailed mechanism under isothermal plug flow reactor conditions. While none of the global ammonia...... approach with the De Soete global scheme and the combination of a skeletal combustion mechanism with the analytically reduced N scheme provided it reasonable agreement with the experimental data. Most of the tested ammonia oxidation schemes were able to qualitatively predict the trends in NO formation...

  12. Experimental investigations of the electron cloud key parameters

    International Nuclear Information System (INIS)

    Motivated by a potential electron cloud instability and the possible existence of electron multipacting in the LHC vacuum system, that may result in additional gas desorption and unmanageable heat loads on the cryogenic system, and extensive experimental research program is underway at CERN to quantify the key parameters driving these phenomena. Parameters, such as: photoelectron yield, photon reflectivity, secondary electron yield etc from industrially prepared surfaces have been quantified. In addition to their dependence on photon dose the effect of temperature and presence of external fields has also been studied. (author)

  13. An experimental investigation of post dryout heat transfer

    International Nuclear Information System (INIS)

    The present report contains the results of post-dryout measurements which have been carried out in the Department of Nuclear Reactor Engineering at the Royal Institute of Technology. More than 15000 heat transfer coefficients were obtained for electrically heated round tubes in the post-dryout regime, covering the following ranges of parameters: Heated length L=7000 mm, Inner diameter d(sub)i=14.90, 10.00 and 24.69 mm, Inlet subcooling ?t(sub)i=10degreeC, Pressure p=30-205 bar, Mass velocity G=500-3000 kg/m2s, Heat flux g/A=9-125 W/cm2, PDO steam quality x(sub)PDO=0.03-1.66. A brief description of the experimental equipment is given as well as a table containing the experimental results. The data have been stored on a tape which is available at the department of Nuclear Reactor Engineering at the Royal Institute of Technology. (author)

  14. Investigating Climate Change and Reproduction: Experimental Tools from Evolutionary Biology

    Directory of Open Access Journals (Sweden)

    Oliver Y. Martin

    2012-09-01

    Full Text Available It is now generally acknowledged that climate change has wide-ranging biological consequences, potentially leading to impacts on biodiversity. Environmental factors can have diverse and often strong effects on reproduction, with obvious ramifications for population fitness. Nevertheless, reproductive traits are often neglected in conservation considerations. Focusing on animals, recent progress in sexual selection and sexual conflict research suggests that reproductive costs may pose an underestimated hurdle during rapid climate change, potentially lowering adaptive potential and increasing extinction risk of certain populations. Nevertheless, regime shifts may have both negative and positive effects on reproduction, so it is important to acquire detailed experimental data. We hence present an overview of the literature reporting short-term reproductive consequences of exposure to different environmental factors. From the enormous diversity of findings, we conclude that climate change research could benefit greatly from more coordinated efforts incorporating evolutionary approaches in order to obtain cross-comparable data on how individual and population reproductive fitness respond in the long term. Therefore, we propose ideas and methods concerning future efforts dealing with reproductive consequences of climate change, in particular by highlighting the advantages of multi-generational experimental evolution experiments.

  15. Investigating climate change and reproduction: experimental tools from evolutionary biology.

    Science.gov (United States)

    Grazer, Vera M; Martin, Oliver Y

    2012-01-01

    It is now generally acknowledged that climate change has wide-ranging biological consequences, potentially leading to impacts on biodiversity. Environmental factors can have diverse and often strong effects on reproduction, with obvious ramifications for population fitness. Nevertheless, reproductive traits are often neglected in conservation considerations. Focusing on animals, recent progress in sexual selection and sexual conflict research suggests that reproductive costs may pose an underestimated hurdle during rapid climate change, potentially lowering adaptive potential and increasing extinction risk of certain populations. Nevertheless, regime shifts may have both negative and positive effects on reproduction, so it is important to acquire detailed experimental data. We hence present an overview of the literature reporting short-term reproductive consequences of exposure to different environmental factors. From the enormous diversity of findings, we conclude that climate change research could benefit greatly from more coordinated efforts incorporating evolutionary approaches in order to obtain cross-comparable data on how individual and population reproductive fitness respond in the long term. Therefore, we propose ideas and methods concerning future efforts dealing with reproductive consequences of climate change, in particular by highlighting the advantages of multi-generational experimental evolution experiments. PMID:24832232

  16. Experimental investigation two phase flow in direct methanol fuel cells

    International Nuclear Information System (INIS)

    Direct methanol fuel cells (DMFC) have received many attentions specifically for portable electronic applications since it utilize methanol which is in liquid form in atmospheric condition and high energy density of the methanol. Thus it eliminates the storage problem of hydrogen. It also eliminates humidification requirement of polymeric membrane which is a problem in PEM fuel cells. Some electronic companies introduced DMFC prototypes for portable electronic applications. Presence of carbon dioxide gases due to electrochemical reactions in anode makes the problem a two phase problem. A two phase flow may occur at cathode specifically at high current densities due to the excess water. Presence of gas phase in anode region and liquid phase in cathode region prevents diffusion of fuel and oxygen to the reaction sites thus reduces the performance of the system. Uncontrolled pressure buildup in anode region increases methanol crossover through membrane and adversely effect the performance. Two phase flow in both anode and cathode region is very effective in the performance of DMYC system and a detailed understanding of two phase flow for high performance DMFC systems. Although there are many theoretical and experimental studies available on the DMFC systems in the literature, only few studies consider problem as a two-phase flow problem. In this study, an experimental set up is developed and species distributions on system are measured with a gas chromatograph. System performance characteristics (V-I curves) is measured depending on the process parameters (temperature, fuel ad oxidant flow rates, methanol concentration etc)

  17. Control strategies for friction dampers: numerical assessment and experimental investigations.

    Directory of Open Access Journals (Sweden)

    Coelho H.T.

    2014-01-01

    Full Text Available The use of friction dampers has been proposed in a wide variety of mechanical systems for which it is not possible to apply viscoelastic materials, fluid based dampers or others viscous dampers. An important example is the application of friction dampers in aircraft engines to reduce the blades vibration amplitudes. In most cases, friction dampers have been studied in a passive way, however, a significant improvement can be achieved by controlling the normal force in the dampers. The aim of this paper is to study three control strategies for friction dampers based on the hysteresis cycle. The first control strategy maximizes the energy removal in each harmonic oscillation cycle, by calculating the optimum normal force based on the last displacement peak. The second control strategy combines the first one with the maximum energy removal strategy used in the smart spring devices. Finally, is presented the strategy which homogenously modulates the friction force. Numerical studies were performed with these three strategies defining the performance metrics. The best control strategy was applied experimentally. The experimental test rig was fully identified and its parameters were used for the numerical simulations. The obtained results show the good performance for the friction damper and the selected strategy.

  18. Experimental Investigations on Performance and Design Parameters of Solar Chimney

    Directory of Open Access Journals (Sweden)

    ?brahim ÜÇGÜL

    2010-03-01

    Full Text Available In this study, a solar chimney system, which is suitable for climate conditions of Isparta and its surroundings, is designed theoretically. With the aim of studying experimentally as based on that design, a prototype solar chimney has been constructed in the university campus area of Süleyman Demirel University-RACRER (Research and Application Center for Renewable Energy Resources. Additionally, after the experimental studies, the system is modelled theoretically with depending on the design. Then, this model constituted the basis for developed computer programme and performance parameters of the system are obtained. The obtained findings showed that the solar chimney, which is suitable for climate conditions of Isparta and its surroundings, are sufficient for determining design and performance parameters. The results showed that electricity generation with solar chimney is suitable for areas which have high solar incident and long sunshine duration and similar climate conditions as such as Isparta and its surroundings. When the results are evaluated, it is seen that electricity generation power of solar chimney depends on the region solar data, the chimney height and the size of greenhouse area.

  19. Experimental investigations of the hydraulics of PFBR steam generator

    International Nuclear Information System (INIS)

    The 500 MWe Prototype Fast Breeder Reactor (PFBR) being constructed at Kalpakkam in India, employ liquid sodium as the coolant. Steam generator units are shell and tube heat exchangers with sodium flowing on the shell side and water/steam on the tube side. Liquid sodium enters into the shell side through a side nozzle rises up in the annular space, enters into the window of tube bundle and then flows down along the tubes exchanging heat. The crossflow at tube bundle window has major influence on the flow-induced vibration (FIV) of the tubes and on the temperature profile of the steam exiting from the tubes. A near uniform flow distribution at the inlet of the tube bundle and optimum crossflow velocity are vital for the above mentioned. A scaled down model of the prototype of size 3/5 with velocity similitude was used to conduct hydraulic studies in water to determine the flow distribution and flow distribution devices were employed to achieve flow uniformity. A 60-degree sector of the PFBR SG was tested in water to establish the velocity profile and to monitor the flow induced vibration characteristics. The results of the experiments were compared with the predictions of the analysis arrived using computational tools. From the experimental studies and the theoretical analysis on the sector model an acceptable velocity distribution for the SG tubes against failure due to FIV has been established. This paper discusses the experimental study, the measurements and the analysis of the results. (author)

  20. Incipient Transient Detection in Reactor Systems: Experimental and Theoretical Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Lefteri H. Tsoukalas; S.T. Revankar; X Wang; R. Sattuluri

    2005-09-27

    The main goal of this research was to develop a method for detecting reactor system transients at the earliest possible time through a comprehensive experimental, testing and benchmarking program. This approach holds strong promise for developing new diagnostic technologies that are non-intrusive, generic and highly portable across different systems. It will help in the design of new generation nuclear power reactors, which utilize passive safety systems with a reliable and non-intrusive multiphase flow diagnostic system to monitor the function of the passive safety systems. The main objective of this research was to develop an improved fuzzy logic based detection method based on a comprehensive experimental testing program to detect reactor transients at the earliest possible time, practically at their birth moment. A fuzzy logic and neural network based transient identification methodology and implemented in a computer code called PROTREN was considered in this research and was compared with SPRT (Sequentially Probability Ratio Testing) decision and Bayesian inference. The project involved experiment, theoretical modeling and a thermal-hydraulic code assessment. It involved graduate and undergraduate students participation providing them with exposure and training in advanced reactor concepts and safety systems. In this final report, main tasks performed during the project period are summarized and the selected results are presented. Detailed descriptions for the tasks and the results are presented in previous yearly reports (Revankar et al 2003 and Revankar et al 2004).

  1. Experimental investigation of the steam condensation with air and helium

    Science.gov (United States)

    Su, Jiqiang; Sun, Zhongning; Fan, Guangming; Ding, Ming

    2013-07-01

    Condensation of steam coming out from the coolant pipe during a loss of coolant accident (LOCA) plays a key role in removing heat from the primary containment of the nuclear reactor. The presence of air and helium reduces the overall heat transfer coefficient substantially. Condensation experiments in the presence of non-condensable gases (e.g. air, helium) were conducted to evaluate the heat removal capacity of a vertical mounted smooth tube. The influences of various parameters, especially the wall subcooling, on the steam condensation heat transfer with non-condensable gases have been obtained for the wall subcooling ranging from 20 to 70°C, total pressure ranging from 2.0×105 Pa to 7.0×105 Pa and air mass fraction ranging from 0.10 to 0.95. The empirical correlations for the heat transfer coefficient, consisting of the mass fraction of the non-condensable gases (air/air helium), total pressure, wall subcooling, and helium mole fraction in non-condensable gases, have been developed based on the experimental results. The relative error of proposed correlations with experimental data is less than 10%. The helium stratification on the condensation has been researched from the distribution of helium fraction and the bulk temperature at different axial positions. It shows that the helium stratification can be ignored when the helium mole fraction in non-condensable gases is less than 35%.

  2. Local and Remote Laboratory User Experimentation Access using Digital Programmable Logic

    Directory of Open Access Journals (Sweden)

    Ian A Grout

    2005-06-01

    Full Text Available This paper will discuss the structure and operation of a programmable logic based experimentation arrangement that is suitable for both local and remote teaching and learning scenarios targeting electronic and microelectronic circuit design and test principles. With this experimentation arrangement, the ability to provide both local and Internet based “remote” access for the student and the teacher can provide a number of advantages where physical laboratory accessibility is limited and/or the learning experience must be undertaken with one or more of the parties remotely based. The paper concentrates on the design and example use of a system developed within the University of Limerick.

  3. Exploratory experimental investigations on post-tensioned structural glass beams

    DEFF Research Database (Denmark)

    Louter, C.; Nielsen, Jens Henrik; Belis, J.

    enhance the initial failure stress of the glass and to obtain ductile (post-breakage) performance. From four-point bending tests on the post-tensioned glass beam specimens it is observed that these goals are reached. From the test results it is concluded that post-tensioning glass beams is a feasible and...... promising concept, which provides enhanced strength and ductile (post-breakage) performance. Since the current investigations are exploratory, the investigated concepts leave unsolved challenges for future research within this field....

  4. Experimental and Theoretical Investigation of Instability within a Heated Meniscus

    Science.gov (United States)

    Garcia, Michel

    The behaviour of heated, evaporating menisci in capillary tubes was experimentally observed and theoretically predicted. Testing was performed with n-pentane as a working fluid evaporating in both ambient air (multicomponent, multiphase environment) and a chamber filled with its saturated vapour (single-component, multiphase environment). Capillary tubes with both thin and thick walls with comparable internal diameters were tested. Thermocouples were embedded inside the thick tubes and epoxied onto the thin tubes. A carbon composite resistive element was deposited onto each tube for electrical heating. A meniscus was positioned between tube thermocouples and electrical heating was provided until the meniscus was observed to oscillate in the axial direction, at which time it was considered destabilised. The experimental temperature gradient at the onset of instability was found to be significantly different for thin and thick tubes of comparable inner diameters. Thin tube results were determined to be more representative of the axial temperature gradient at the tube inner wall. Oscillations were observed and recorded using a microscope-camera assembly. Meniscal instability occurred at a higher temperature gradient for testing while exposed to ambient air than for testing in a pure n-pentane environment. A meniscus inside a smaller inner diameter tube was found to be capable of sustaining a larger temperature gradient than that for a meniscus inside a larger inner diameter tube. A leading-order scaled equation describing the evolution of the thin film was derived and a perturbation analysis was applied to obtain a stability criterion. A characteristic height was chosen as the height at which the evaporative mass flux was a maximum. The meniscus half channel width was chosen as the characteristic length normal to the characteristic height. A numerical thin film model was created to obtain the characteristic height from the thin film solution profile together with the calculated value of the stability criterion. Comparison with experimental results showed that the model has some predictive ability in determining the onset of evaporating meniscal instability in a heated capillary tube. Results of this study can be used to design and characterise the operational limits of phase change heat transfer devices using evaporation from a meniscus as would occur in heat pipes.

  5. Experimental investigation of the Fast-SAGD process

    Energy Technology Data Exchange (ETDEWEB)

    Shin, H. [Shell Canada Ltd., Calgary, AB (Canada); Polikar, M. [Alberta Univ., Edmonton, AB (Canada)

    2006-07-01

    High pressure and high temperature experiments were conducted to provided insight into the operation of the steam assisted gravity drainage (SAGD) process and its modified Fast-SAGD process. A mechanism for the steam chamber's collapse and recovery was suggested. Steam chamber growth is accelerated sideways in this enhanced recovery method which uses offset wells operated with cyclic steam stimulation (CSS) beside the SAGD well. The enhanced thermal efficiency offered by Fast-SAGD results in better production performance compared to conventional SAGD. The application of the Fast-SAGD process in Alberta's oil sands areas has resulted in higher net present values (NPV) for the low permeability type reservoirs of Cold Lake and Peace River because of lower steam requirements and higher productivity. In this study, the Fast SAGD process was evaluated using an automated process control system for a scaled physical model which represented a bituminous reservoir near Cold Lake being operated at high temperature and high pressure conditions. A suitable permeability of 1.25 Darcy was chosen for the prototype based on numerical simulations. Experimental results revealed that, for the Fast-SAGD process, the overall cumulative oil production is larger and the end-point cumulative steam to oil ratio (CSOR) is higher than for the SAGD process. The authors deduced that for the Fast-SAGD experiment, the steam chamber collapsed because the boiler did not produce a sufficient volume of high quality steam. Numerical simulation results confirmed this assumption. The steam chamber was then restored by modifying the experimental procedure. Best history matches showed the steam quality was 30 per cent during the SAGD and then 15 per cent after starting the CSS. It was concluded that if the same quality of steam were injected into the Fast- SAGD model as in the SAGD case, the experimental results of the Fast-SAGD case would be improved, cumulative production by 70 per cent and the CSOR by 52 per cent. 8 refs., 2 tabs., 24 figs.

  6. An experimental investigation of interaction between projectiles and flames

    Science.gov (United States)

    Baryshnikov, A. S.; Basargin, I. V.; Bobashev, S. V.; Monakhov, N. A.; Popov, P. A.; Sakharov, V. A.; Chistyakova, M. V.

    2015-12-01

    This investigation is devoted to the influence of a heated area of gas on model stability with the supersonic motion during free-flying operation. The conditions of the maximum influence on aerodynamics of body flight in an inhomogeneous heated area are ascertained.

  7. Experimental investigation of in situ cleanable HEPA filters

    International Nuclear Information System (INIS)

    Savannah River Technology Center (SRTC), High Level Waste Division, Tanks Focus Area, and the Federal Energy Technology Center (FETC) have been investigating high efficiency particulate air (HEPA) filters which can be regenerated or cleaned in situ as an alternative to conventional disposable HEPA filters. This technical report documents concerns pertaining to conventional HEPA filters

  8. Experimental investigation of interaction processes between diesel-sprays

    Energy Technology Data Exchange (ETDEWEB)

    Pawlowski, Adam Zbigniew

    2009-07-01

    This thesis addresses some fundamental questions about spray-spray interaction. The combination of the employed measurement techniques allows comprehensive insights into this phenomena. The sprays from the investigated set of cluster nozzles behave considerably different than sprays from a conventional nozzle. This is expected to be true for all diverging cluster nozzles with a significant angle between the sprays. Diverging cluster sprays offer an additional possibility for engine designers to influence the fuel distribution inside the combustion chamber. However, the sprays investigated here behave so different, that other engine parameters like piston geometry may need to be modified to use the full potential of such nozzles. Contrary to the large differences between the investigated conventional and cluster nozzles, no significant effect has been noted for conventional multi-hole nozzles in terms of entrainment between the sprays. For the currently employed number of orifices per nozzle (6-8); increasing the number of orifices alone seems to have no significant impact on the flow field between the sprays and therefore on the entrainment. This finding is supported by a simple integral entrainment model. The investigations presented here indicate that in engines these processes are governed by the geometry and probably also by the interaction with charge motion. Therefore, studying these processes in greater detail in pressurized chambers seems unreasonable. (orig.)

  9. Investigation of the fast neutron induced (n, ?) reaction. (Experimental techniques)

    International Nuclear Information System (INIS)

    For investigation of the fast neutron induced (n, ?)-reaction, two grid-type gas-filled twin ionization chambers were developed and tested. Using the ionization chambers, the energy spectra, angular distributions and cross sections of the (n, ?)-reaction were measured around En=5 MeV for 40Ca, 58Ni and 64Zn. 27 refs., 20 figs., 1 tab

  10. Experimental investigation of AC interference on cathodically protected gas pipelines

    Energy Technology Data Exchange (ETDEWEB)

    AllahKaram, S.R.; Shamani, R. [Metallurgy and Materials Department, Faculty of Engineering, University of Tehran, Tehran (Iran)

    2004-07-01

    Due to the expansion of high voltage AC power transmission lines and cathodically protected gas pipelines corresponding to the increases in energy demand, it is more difficult to construct them with enough distances between them. Thus, the pipelines are exposed to AC interference, which results in perturbation of cathodic protection and AC corrosion risk. The monitoring system used the instant-off method, with steel probes simulating coating defects. IR free potential monitoring under AC conditions is difficult to measure. The ohmic drop error due to AC current can be much more important than the error due to DC cathodic protection currents. By increasing the data acquisition rate, it has been possible to determine the polarization of the metal surface within a few milliseconds after disconnecting the coupon from the AC and DC power source. Some of the conclusions of these studies are that: - AC polarization can decay some of the protective films. - The electrochemical surface reactions and therefore the interpretation of the instantaneous off potential measurements depend strongly on the composition of the soil. The details of the method, the equipment, the results of laboratory studies, the interpretation of the data and the identification of conditions for AC corrosion have been presented. (authors)

  11. Experimental investigation of the ecological hybrid refrigeration cycle

    Science.gov (United States)

    Cyklis, Piotr; Kantor, Ryszard; Ryncarz, Tomasz; Górski, Bogus?aw; Duda, Roman

    2014-09-01

    The requirements for environmentally friendly refrigerants promote application of CO2 and water as working fluids. However there are two problems related to that, namely high temperature limit for CO2 in condenser due to the low critical temperature, and low temperature limit for water being the result of high triple point temperature. This can be avoided by application of the hybrid adsorption-compression system, where water is the working fluid in the adsorption high temperature cycle used to cool down the CO2 compression cycle condenser. The adsorption process is powered with a low temperature renewable heat source as solar collectors or other waste heat source. The refrigeration system integrating adsorption and compression system has been designed and constructed in the Laboratory of Thermodynamics and Thermal Machine Measurements of Cracow University of Technology. The heat source for adsorption system consists of 16 tube tulbular collectors. The CO2 compression low temperature cycle is based on two parallel compressors with frequency inverter. Energy efficiency and TEWI of this hybrid system is quite promising in comparison with the compression only systems.

  12. Experimental investigation of the ecological hybrid refrigeration cycle

    Directory of Open Access Journals (Sweden)

    Cyklis Piotr

    2014-09-01

    Full Text Available The requirements for environmentally friendly refrigerants promote application of CO2 and water as working fluids. However there are two problems related to that, namely high temperature limit for CO2 in condenser due to the low critical temperature, and low temperature limit for water being the result of high triple point temperature. This can be avoided by application of the hybrid adsorption-compression system, where water is the working fluid in the adsorption high temperature cycle used to cool down the CO2 compression cycle condenser. The adsorption process is powered with a low temperature renewable heat source as solar collectors or other waste heat source. The refrigeration system integrating adsorption and compression system has been designed and constructed in the Laboratory of Thermodynamics and Thermal Machine Measurements of Cracow University of Technology. The heat source for adsorption system consists of 16 tube tulbular collectors. The CO2 compression low temperature cycle is based on two parallel compressors with frequency inverter. Energy efficiency and TEWI of this hybrid system is quite promising in comparison with the compression only systems.

  13. Experimental Investigation of a Helicopter Rotor Hub Wake

    Science.gov (United States)

    Reich, David; Elbing, Brian; Schmitz, Sven

    2013-11-01

    A scaled model of a notional helicopter rotor hub was tested in the 48'' Garfield Thomas Water Tunnel at the Applied Research Laboratory Penn State. The main objectives of the experiment were to understand the spatial- and temporal content of the unsteady wake downstream of a rotor hub up to a distance corresponding to the empennage. Primary measurements were the total hub drag and velocity measurements at three nominal downstream locations. Various flow structures were identified and linked to geometric features of the hub model. The most prominent structures were two-per-revolution (hub component: scissors) and four-per-revolution (hub component: main hub arms) vortices shed by the hub. Both the two-per-revolution and four-per-revolution structures persisted far downstream of the hub, but the rate of dissipation was greater for the four-per-rev structures. This work provides a dataset for enhanced understanding of the fundamental physics underlying rotor hub flows and serves as validation data for future CFD analyses.

  14. Exploratory experimental investigations on post-tensioned structural glass beams

    Directory of Open Access Journals (Sweden)

    Christian Louter

    2014-06-01

    Full Text Available Corresponding author: Dr. ir. Christian Louter, Steel Structures Laboratory (ICOM, School of Architecture, Civil and Environmental Engineering (ENAC, École Polytechnique Fédérale de Lausanne (EPFL, GC B3 505, Station 18, Lausanne CH-1015, Switzerland. Tel.: +41 21 6932427; Fax: +41 21 6932868; E-mail: christian.louter@epfl.ch The mechanical response of post-tensioned glass beams is explored in this paper. This is done through bending experiments on post-tensioned glass beam specimens with either mechanically anchored or adhesively bonded steel tendons by which a beneficial pre-stress is inflicted on the glass beams. In addition, reference beams with identical geometry but without tendons are tested. From the results of the bending experiments it can be seen that the post-tensioned glass beams reach higher initial fracture loads than the reference glass beams. Furthermore, the post-tensioned glass beams develop a significant post-fracture reserve. From this it is concluded that post-tensioning a glass beam is a feasible concept, which provides increased initial fracture strength and enhanced post-fracture performance.

  15. An experimental investigation of double beta decay of 100Mo

    International Nuclear Information System (INIS)

    New limits on half-lives for several double beta decay modes of 100Mo were obtained with a novel experimental system which included thin source films interleaved with a coaxial array of windowless silicon detectors. Segmentation and timing information allowed backgrounds originating in the films to be studied in some detail. Dummy films containing 96Mo were used to assess remaining backgrounds. With 0.1 mole years of 100Mo data collected, the lower half-life limits at 90% confidence were 2.7 /times/ 1018 years for decay via the two-neutrino mode, 5.2 /times/1019 years for decay with the emission of a Majoron, and 1.6 /times/ 1020 years and 2.2 /times/ 1021 years for neutrinoless 0+ ? 2+ and 0+ ? 0+ transitions, respectively. 50 refs., 38 figs., 11 tabs

  16. EXPERIMENTAL INVESTIGATION & NUMERICAL ANALYSIS OF COMPOSITE LEAF SPRING

    Directory of Open Access Journals (Sweden)

    K. K. JADHAO,

    2011-06-01

    Full Text Available The Automobile Industry has shown keen interest for replacement of steel leaf spring with that of glass fiber composite leaf spring, since the composite material has high strength to weight ratio, good corrosion resistance and tailor-able properties. The objective of present study was to replace material for leaf spring. In present study the material selected was glass fiber reinforced plastic (GFRP and the polyester resin (NETPOL 1011 can be used which was more economical this will reduce total cost of composite leaf spring. A spring with constant width and thickness was fabricated by hand lay-up technique which was very simple and economical. The experiments were conducted on UTM and numerical analysis was done via (FEA using ANSYS software. Stresses and deflection results were verified for analytical and experimental results. Result shows that, the composite spring has stresses much lower than steel leaf spring and weight of composite spring was nearly reduced up to 85%.

  17. Theoretical and experimental investigation of magnetotransport in iron chalcogenides

    Directory of Open Access Journals (Sweden)

    Federico Caglieris, Fabio Ricci, Gianrico Lamura, Albert Martinelli, A Palenzona, Ilaria Pallecchi, Alberto Sala, Gianni Profeta and Marina Putti

    2012-01-01

    Full Text Available We explore the electronic, transport and thermoelectric properties of Fe1+ySexTe1?x compounds to clarify the mechanisms of superconductivity in Fe-based compounds. We carry out first-principles density functional theory (DFT calculations of structural, electronic, magnetic and transport properties and measure resistivity, Hall resistance and Seebeck effect curves. All the transport properties exhibit signatures of the structural/magnetic transitions, such as discontinuities and sign changes of the Seebeck coefficient and of the Hall resistance. These features are reproduced by calculations provided that antiferromagnetic correlations are taken into account and experimental values of lattice constants are considered in DFT calculations. On the other hand, the temperature dependences of the transport properties can not be fully reproduced, and to improve the agreement between experiment and DFT calculations it is necessary to go beyond the constant relaxation time approximation and take into account correlation effects.

  18. Experimental, quantum chemical and NBO/NLMO investigations of pantoprazole

    Science.gov (United States)

    Rajesh, P.; Gunasekaran, S.; Gnanasambandan, T.; Seshadri, S.

    2015-02-01

    The complete vibrational assignment and analysis of the fundamental modes of pantoprazole (PPZ) was carried out using the experimental FT-IR, FT-Raman and UV-Vis data and quantum chemical studies. The observed vibrational data were compared with the wavenumbers derived theoretically for the optimized geometry of the compound from the DFT-B3LYP gradient calculations employing 6-31G (d, p) basis set. Thermodynamic properties like entropy, heat capacity and enthalpy have been calculated for the molecule. HOMO-LUMO energy gap has been calculated. The intramolecular contacts have been interpreted using natural bond orbital (NBO) and natural localized molecular orbital (NLMO) analysis. Important non-linear properties such as electric dipole moment and first hyperpolarizability of PPZ have been computed using B3LYP quantum chemical calculation. Finally, the Mulliken population analysis on atomic charges of the title compound has been calculated.

  19. Experimental Investigation of Tesla Turbine and its Underlying Theory

    Directory of Open Access Journals (Sweden)

    Kartikeya Awasthi

    2014-07-01

    Full Text Available Nikola Tesla is widely known for his outstanding achievements in generation transmission and utilization of power. The object of this paper is to experimentally verify one such method of extracting electrical power from fluid energy; devised by Tesla in his 1913 patent; known as Tesla Turbine. It is to be noted that almost no work has been done using water as the working fluid for the turbine so an attempt to reconstruct the turbine as per Nikola Tesla’s patent has been made with positive results obtained by generation of useful electrical power using water as the medium which provides a new outlook towards our understanding of the turbines and the ways by which mechanical energy of the motive fluid can be converted into useful electrical output. .

  20. Performance enhancement of solar module by cooling: An experimental investigation

    Directory of Open Access Journals (Sweden)

    P G Nikhil, M Premalatha

    2012-01-01

    Full Text Available The study evaluates the silicone oil cooling of the solar module surface. Solar module with maximum power of 7W was employed for cooling. This paper summarizes the result of an outdoor experiment. The experiments were conducted in batch mode, with the cooling medium spread on the module surface at different thickness from 0mm to 6mm. The performance of the module, throughout the day, for different thickness of the medium is reported. The study also presents a mathematical model, predicting the variation of the maximum power when the module surface is cooled using silicone oil. The results of the equation model are compared and validated with the experimental as well as with results reported in the earlier works. The cooling contributes to appreciable improvement in the module efficiency to above 20%.

  1. Experimental investigation of cavitation behavior in valveless micropumps

    International Nuclear Information System (INIS)

    Recently, there have been several reports on the observation of cavitation in microfluidics and in micropumps. Though cavitation is a common occurrence in micropumping, this is one of the least understood of all micropumping phenomena, and very limited progress has been made to study the behavior of cavitation in micropumps. Hence, a dedicated study on cavitation in micropumps and its effects on the performance of the micropump would be very useful. This work presents an experimental study on the behavior of cavitation in valveless micropump. The mechanism of cavitation occurrence in valveless micropumps has been explained by applying macroscale pumping principles to suit micropumping. The different stages of micropump cavitation have been defined through suitably conducted experiments and the results have been presented. (paper)

  2. Experimental Investigation of Dynamic Behavior of Viaducts by Shock Loading

    Directory of Open Access Journals (Sweden)

    Adrian Leopa

    2011-09-01

    Full Text Available The viaducts are constructions designed to provide ground communication over different geographical barriers such as examples valleys (depressions. To avoid partial or total destruction that may occur after dynamic stress from road (or railroad or seismic activity, in viaducts structure is placed systems for dynamic isolation. Thus, the viaduct deck is mounted on viscoelastic type systems designed to provide protection from the shock loading. Over time, due to an intensive and varied of dynamic loadings, these isolation systems suffer degradation of viscoelastic links, something that leads to uncontrolled movements of the system. In this work, are established and quantified on experimental way, kinematics parameters of the vibration of the viaduct deck loading by shocks, which will be monitored over time to establish the degree of normality in the functioning of viscoelastic systems.

  3. Experimental investigation of dynamic properties of chemical control analyzers

    Science.gov (United States)

    Egoshina, O. V.; Voronov, V. N.; Makarishcheva, N. A.; Latt, Aie Min; Rogov, A. S.

    2015-05-01

    General data on dynamical characteristics of chemical control analyzers under nonstationary conditions are represented. The concise description of an experimental bench modeling the operation of a chemical-engineering monitoring system with the technical specifications of analyzers is given. Basic principles for determining dynamic characteristics of the analyzers are formulated. Results of computations of mathematical models for different types of disturbances that imitate a violation in water chemistry and the failure of single equipment components in systems for chemical control of the quality of a heat-transfer agent using in HPPs and NPPs are given. Conclusions are drawn regarding the necessity in the mandatory consideration of the dynamic characteristics during the construction of automatic systems for dozing correction reagents.

  4. Back scattering interferometry revisited – A theoretical and experimental investigation

    DEFF Research Database (Denmark)

    Jørgensen, Thomas Martini; Jepsen, S. T.; Sørensen, Henrik Schiøtt; K. di Gennaro, A.; Kristensen, S. R.

    2015-01-01

    A refractive index based detector based on so called back scattering interferometry (BSI) has been described in the literature as a unique optical method for measuring biomolecular binding interactions in solution. In this paper, we take a detailed look at the optical principle underlying this...... technique to understand fully the constituents and behaviour of the fringe patterns generated. The simulated results are compared and validated with experimental measurements. Hereby, we show that BSI does not operate as a resonant cavity as often stated in the literature. Recently, we have questioned the...... claims made that BSI in general can be used to measure molecular bindings. Here we explore this topic further in three cases using fluorescence spectroscopy as a reference method. Finally, we explore whether refractive index sensing can be used to measure the enzymatic phosphorylation of glucose to...

  5. Experimental Investigation of Hypersonic Flow and Plasma Aerodynamic Actuation Interaction

    International Nuclear Information System (INIS)

    For hypersonic flow, it was found that the most effective plasma actuator is derived from an electromagnetic perturbation. An experimental study was performed between hypersonic flow and plasma aerodynamic actuation interaction in a hypersonic shock tunnel, in which a Mach number of 7 was reached. The plasma discharging characteristic was acquired in static flows. In a hypersonic flow, the flow field can affect the plasma discharging characteristics. DC discharging without magnetic force is unstable, and the discharge channel cannot be maintained. When there is a magnetic field, the energy consumption of the plasma source is approximately three to four times larger than that without a magnetic field, and at the same time plasma discharge can also affect the hypersonic flow field. Through schlieren pictures and pressure measurement, it was found that plasma discharging could induce shockwaves and change the total pressure and wall pressure of the flow field

  6. Back scattering interferometry revisited – A theoretical and experimental investigation

    DEFF Research Database (Denmark)

    JØrgensen, Thomas Martini; Jepsen, S. T.

    2015-01-01

    A refractive index based detector based on so called back scattering interferometry (BSI) has been described in the literature as a unique optical method for measuring biomolecular binding interactions in solution. In this paper, we take a detailed look at the optical principle underlying this technique to understand fully the constituents and behaviour of the fringe patterns generated. The simulated results are compared and validated with experimental measurements. Hereby, we show that BSI does not operate as a resonant cavity as often stated in the literature. Recently, we have questioned the claims made that BSI in general can be used to measure molecular bindings. Here we explore this topic further in three cases using fluorescence spectroscopy as a reference method. Finally, we explore whether refractive index sensing can be used to measure the enzymatic phosphorylation of glucose to glucose-6-phosphate.

  7. Experimental Investigation on Sandstone Rock Permeability of Pakistan Gas Fields

    Science.gov (United States)

    Raza, Arshad; Bing, Chua Han; Nagarajan, Ramasamy; Hamid, Mohamed Ali

    2015-04-01

    Permeability is the ability of formation to produce hydrocarbon which is affected by compaction, pore size, sorting, cementation, layering and clay swelling. The effect of texture on permeability in term of grain size, sorting, sphericity, degree of cementing has been reported in literature. Also, the effect of permeability on capillary pressure, irreducible water saturation, displacement pressure and pore geometry constant has been studied separately. This preliminary study presents the experimental results of eight samples to understand the effect of similar factors of texture on permeability. With the knowledge of the results, it can be said that the effect of grain size, cementation, texture material, sphericity, and porosity can't be observed on permeability except sorting when less than ten samples are considered from different depositional environment. The results also show the impact of permeability on capillary pressure, irreducible water saturation, and displacement pressure and pore geometry index as similar as published in the literature.

  8. Experimental Investigation of the Equal Channel Forward Extrusion Process

    Directory of Open Access Journals (Sweden)

    Mahmoud Ebrahimi

    2015-03-01

    Full Text Available Among all recognized severe plastic deformation techniques, a new method, called the equal channel forward extrusion process, has been experimentally studied. It has been shown that this method has similar characteristics to other severe plastic deformation methods, and the potential of this new method was examined on the mechanical properties of commercial pure aluminum. The results indicate that approximate 121%, 56%, and 84% enhancements, at the yield strength, ultimate tensile strength, and Vickers micro-hardness measurement are, respectively, achieved after the fourth pass, in comparison with the annealed condition. The results of drop weight impact test showed that the increment of 26% at the impact force, and also decreases of 32%, 15%, and 4% at the deflection, impulse, and absorbed energy, are respectively attained for the fourth pass when compared to the annealed condition. Furthermore, the electron backscatter diffraction examination revealed that the average grain size of the final pass is about 480 nm.

  9. Experimental, analytical and computational investigation of bimodal elastomer networks

    Science.gov (United States)

    von Lockette, Paris Robert

    Advances in the synthesis of macromolecular materials have led to the creation of special classes of elastomers called bimodal because of their bimodal distributions of linear starting oligomers. Numerous studies on these materials have documented anomalous increases in ultimate strength and toughness at certain mixture combinations of the constituents but have not yet identified a cause for this behavior. In addition, the ability to predict optimal mixtures still eludes polymer chemists. Constitutive models for the behavior of bimodal materials are also unable to predict material behavior, but instead tend to capture results using complicated curve fitting and iterative schemes. This thesis uncovers topological and micromechanical sources of these enhanced properties using periodic, topological simulations of chain-level network formation and develops a constitutive model of the aggregate bimodal network. Using a topological framework, in conjunction with the eight-chain averaging scheme of Arruda and Boyce, this work develops optical and mechanical constitutive models for bimodal elastomers whose results compare favorably with data in the literature. The resulting bimodal network theory is able to predict material response for a range of bimodal compositions using only two sets of data, a direct improvement over previous models. The micromechanics of elastomeric deformation and chain orientation as described by the eight-chain model are further validated by comparing optical and mechanical data generated during large deformation shear tests on unimodal materials with finite element simulations. In addition, a newly developed optical anisotropy model for the Raman tensor of polymeric materials, generated using an eight-chain unit cell model, is shown to compare favorably with tensile data in the literature. Results generated using NETSIM, a computer program developed in this thesis, have revealed naturally occurring, self-reinforcing topological features associated with experimentally observed increases in ultimate strength and toughness. The ability to predict increases in the populations of these topologies allows for the prediction of optimal bimodal mixtures and the definition of a metric of network optimality. The sol and gel fraction predictions from NETSIM also compare well with results obtained from experimental network synthesis and previous computational simulations. After formation, each molecular chain is assigned a modified entropic force-stretch law and the undeformed network is annealed, clearly illustrating how initial chain length distributions in bimodal materials deviate from the r.m.s. assumption. The results of computational annealing also highlight several structural features that have been observed experimentally in the literature. Results of the computational deformation of simulated, three dimensional networks show enhancements to strain hardening in networks with compositions similar to those which exhibited enhanced toughness in experiments. These enhanced, simulated networks also show increases in the orientation versus stretch response over compositionally similar networks. Orientation response results support previous experimental results. Increased occurrence of the doubled connection topology is found to enhance strain hardening in simulated networks and to be a positive factor in enhanced strain energy seen in experiments. The density of single cyclics, while having a positive correlation in the enhanced strain energy seen in experiments appears to negate the effect of increased populations of doubled connections in simulations.

  10. Experimental investigation of nanosecond discharge plasma aerodynamic actuation

    International Nuclear Information System (INIS)

    In this paper we report on an experimental study of the characteristics of nanosecond pulsed discharge plasma aerodynamic actuation. The N2 (C3?u) rotational and vibrational temperatures are around 430 K and 0.24 eV, respectively. The emission intensity ratio between the first negative system and the second positive system of N2, as a rough indicator of the temporally and spatially averaged electron energy, has a minor dependence on applied voltage amplitude. The induced flow direction is not parallel, but vertical to the dielectric layer surface, as shown by measurements of body force, velocity, and vorticity. Nanosecond discharge plasma aerodynamic actuation is effective in airfoil flow separation control at freestream speeds up to 100 m/s. (physics of gases, plasmas, and electric discharges)

  11. Experimental Investigations of Space Shuttle BX-265 Foam

    Science.gov (United States)

    Lerch, Bradley A.; Sullivan, Roy M.

    2009-01-01

    This report presents a variety of experimental studies on the polyurethane foam, BX-265. This foam is used as a close-out foam insulation on the space shuttle external tank. The purpose of this work is to provide a better understanding of the foam s behavior and to support advanced modeling efforts. The following experiments were performed: Thermal expansion was measured for various heating rates. The in situ expansion of foam cells was documented by heating the foam in a scanning electron microscope. Expansion mechanisms are described. Thermogravimetric analysis was performed at various heating rates and for various environments. The glass transition temperature was also measured. The effects of moisture on the foam were studied. Time-dependent effects were measured to give preliminary data on viscoelastoplastic properties.

  12. Experimental investigation of different configurations in a flexible heliac

    International Nuclear Information System (INIS)

    The effect of varying the magnetic field configuration by adding an l=1 helical winding to the standard heliac has been studied experimentally. Equilibrium plasma configurations in the range 0.7 ? t(0) ? 1.86 have been obtained. Analyses of the plasma pressure profiles measured by Langmuir probes in this range show good agreement between the plasma isobars and the computed vacuum magnetic surfaces; for configurations with a rotational transform t(0) close to unity it is necessary to take known error fields into account. When low-order rational surfaces are present, a deterioration of the plasma confinement is clearly observed. Magnetic islands, resulting from the resonance between the low-order rational surface t = 3/2 and the m=2, n=3 vacuum field harmonics inherent in the geometry, are identified with features observed in both the plasma pressure and the floating potential profiles. (author). 8 refs, 13 figs, 1 tab

  13. An experimental investigation of underexpanded jets from oval sonic nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Rajakuperan, E. [Vikram Sarabhai Space Centre, Trivandrum (India). Aerothermal Test Fac. Div.; Ramaswamy, M.A. [Department of Aerospace Engineering, Indian Institute of Science, Bangalore-560012 (India)

    1998-04-01

    Underexpanded jets from oval sonic nozzles were experimentally studied for various pressure ratios up to 20.3. The results revealed that the barrel type of shock structure was present only in the major axis plane except at low aspect ratios. The results also revealed that the jet spreading rate in the minor axis plane of the nozzle was much higher compared to that in the major axis plane, resulting in axis switching of jets. The cross sectional area of these jets were considerably higher compared to the axisymmetric jets indicating higher interface area for viscous mixing in the near field region and increased mixing in the far field region clear of shock structure. (orig.) With 11 figs., 15 refs.

  14. Experimental Investigation on Terahertz Spectra of Amphetamine Type Stimulants

    Science.gov (United States)

    Sun, Jin-Hai; Shen, Jing-Ling; Liang, Lai-Shun; Xu, Xiao-Yu; Liu, Hai-Bo; Zhang, Cun-Lin

    2005-12-01

    The spectral absorption features of three amphetamine-type stimulants (ATS) belonging to illicit drugs have been studied with terahertz (THz) time-domain spectroscopy (THz-TDS) and the characteristic absorption spectra (fingerprint spectra) are obtained in the range from 0.2 to 2.5 THz. Fingerprint spectra of illicit drugs in terahertz band are bases to detect and to inspect nondestructively illicit drugs with terahertz technique. With fingerprint spectra of illicit drugs and strong penetrability for cloths, paper bags and leathered or plastic luggage terahertz technique would be better than other techniques in illicit drugs detection and inspection. Thus, this work would contribute to the building of corresponding fingerprint spectra database of illicit drugs and provide experimental bases for using of terahertz detection apparatus in drugs nondestructive detection and inspection in the future.

  15. Experimental investigation on air leakage characteristics of containments

    International Nuclear Information System (INIS)

    Facilities such as nuclear power plants have containments as atomic reactor which are subjected to high internal pressure. The internal pressure induces tensile stress in the containments. The tensile stress can cause generation and propagation of cracks through which the gas contaminated radioactively may leak. Supposing that a potential leakage accident happened, an experimental study on air leakage characteristics of containments was carried out. Two reinforced concrete specimens which reflect a wall of the containment were manufactured. Then the specimens were subjected to tensile load to generate cracks and air penetration tests were performed. During the air leakage test, the air pressure of inlet and outlet, the flow rate of outlet and the sum of crack widths were measured. The individual factors of the specific crack shape, the wall roughness and the flow coefficient, could be estimated from these experimental data. The factors are expressed as functions in terms of the sum of crack widths by regression analysis. The measured flow rates were compared with the predictive values obtained using the regression curves. Then flow rates according to pressure gradient and crack width were estimated. It was verified that the predicted flow rates agree with the measured flow rates statistically, that is, the estimated functions predicting the wall roughness and the flow coefficient are suitable. Once the sum of crack widths and inlet pressure of concrete wall are known, thus, the air flow rate can be predicted. The relationship among crack width, pressure and flow rate will serve as a criterion for air leakage characteristics of containments. (authors)

  16. Experimental investigation of heat transfer in the transition region

    International Nuclear Information System (INIS)

    An experimental study of forced convective boiling heat transfer for upflow of water in a circular tube has been performed using a heat transfer system with temperature-controlled indirect Joule heating. By this way, complete boiling curves from incipience of boiling to fully established film boiling could be measured including the transition boiling regime. The boiling curves were traversed in a quasi-steady mode, usually by increasing the set-point wall temperature average at a constant time rate of 3.5 K/min. The vast majority of results covers the pressure range from 0.1 to 1.0 MPa, mass flux range from 25 to 200 kg/(m2s) and inlet subcooling from 5 to 30 K. The experimental results of transition boiling heat transfer obtained in the centre of the test section were correlated in terms of a heat flux/surface superheat relationship that was normalized by the maximum heat flux (local CHF) and its associated wall superheat, respectively, to anchor the transition boiling curve to its low temperature limit. The upper surface temperature limit of the transition boiling regime was determined by inspection of measured axial distributions of surface heat flux and corresponding wall temperature. The critical heat flux (CHF) and its corresponding wall superheat has been measured, too. These temperature-controlled results were compared also with power-controlled experiments. The data are presented in terms of a table and accurate empirical correlations following Katto's generalized correlation scheme. Taking into account previous CHF data at L/D ? 100 and same range of flow conditions the length effect was found to further depend on pressure and mass flux. The data for the critical wall superheat show a distinct dependence upon pressure, mass flux and inlet quality that has not been observed before with comparable clarity

  17. Experimental Investigation of Gas-Lift Use in Nuclear Reactors

    International Nuclear Information System (INIS)

    This work briefly describes the selection of type of a two-phase flow, suitable for intensifying of a natural flow of nuclear reactors with liquid fuel – cooling mixture molten salts and the description of a „Two-phase flow demonstrator“ (TFD) used for experimental study of the „gas-lift“ system, and its influence on the support of natural convection. The experimental device works with water and the air is used as a gas. The used perspex limits the temperature to 60°C. There are stated relations for the description of a natural flow in model device and relations for determination of suitable liquid/gas ratio of the gas-lift in the study. There is described the measuring device and the application of the TFD sensor. The flow rate of water is measured by the induction flow meter that gives a voltage signal, which is brought into a computer for processing. Measuring of the velocity distribution and the size of the bubbles is performed by using the PIV method (Particle Image Velocimetry). There was created a model of dispersive bubble flow for application in nuclear reactors. The basic calculation is performed by using the homogeneous flow, where is considered, that the velocity of the fluid and the gas is equal and there is measured the relative share of the gas in homogeneous mixture with the fluid for this case. There are considered the temperature, pressure and flow rate velocity changes of the fluid and gas in the gas-lift cylinder and their influence on the size and velocity of the bubbles for the heat and mass transport of this mixture by the gas-lift cylinder. (author)

  18. Experimental performance and acoustic investigation of modern, counterrotating blade concepts

    Science.gov (United States)

    Hoff, G. E.

    1990-01-01

    The aerodynamic, acoustic, and aeromechanical performance of counterrotating blade concepts were evaluated both theoretically and experimentally. Analytical methods development and design are addressed. Utilizing the analytical methods which evolved during the conduct of this work, aerodynamic and aeroacoustic predictions were developed, which were compared to NASA and GE wind tunnel test results. The detailed mechanical design and fabrication of five different composite shell/titanium spar counterrotating blade set configurations are presented. Design philosophy, analyses methods, and material geometry are addressed, as well as the influence of aerodynamics, aeromechanics, and aeroacoustics on the design procedures. Blade fabrication and quality control procedures are detailed; bench testing procedures and results of blade integrity verification are presented; and instrumentation associated with the bench testing also is identified. Additional hardware to support specialized testing is described, as are operating blade instrumentation and the associated stress limits. The five counterrotating blade concepts were scaled to a tip diameter of 2 feet, so they could be incorporated into MPS (model propulsion simulators). Aerodynamic and aeroacoustic performance testing was conducted in the NASA Lewis 8 x 6 supersonic and 9 x 15 V/STOL (vertical or short takeoff and landing) wind tunnels and in the GE freejet anechoic test chamber (Cell 41) to generate an experimental data base for these counterrotating blade designs. Test facility and MPS vehicle matrices are provided, and test procedures are presented. Effects on performance of rotor-to-rotor spacing, angle-of-attack, pylon proximity, blade number, reduced-diameter aft blades, and mismatched rotor speeds are addressed. Counterrotating blade and specialized aeromechanical hub stability test results are also furnished.

  19. Developing a new experimental system for an undergraduate laboratory exercise to teach theories of visuomotor learning.

    Science.gov (United States)

    Kasuga, Shoko; Ushiba, Junichi

    2014-01-01

    Humans have a flexible motor ability to adapt their movements to changes in the internal/external environment. For example, using arm-reaching tasks, a number of studies experimentally showed that participants adapt to a novel visuomotor environment. These results helped develop computational models of motor learning implemented in the central nervous system. Despite the importance of such experimental paradigms for exploring the mechanisms of motor learning, because of the cost and preparation time, most students are unable to participate in such experiments. Therefore, in the current study, to help students better understand motor learning theories, we developed a simple finger-reaching experimental system using commonly used laptop PC components with an open-source programming language (Processing Motor Learning Toolkit: PMLT). We found that compared to a commercially available robotic arm-reaching device, our PMLT accomplished similar learning goals (difference in the error reduction between the devices, P = 0.10). In addition, consistent with previous reports from visuomotor learning studies, the participants showed after-effects indicating an adaptation of the motor learning system. The results suggest that PMLT can serve as a new experimental system for an undergraduate laboratory exercise of motor learning theories with minimal time and cost for instructors. PMID:25565915

  20. An experimental investigation into the behavior of glassfiber reinforced polymer elements at elevated temperatures

    Science.gov (United States)

    Qian, Kenny Zongxi

    This thesis presents a literature review and results of an experimental study about the effects of high temperatures and cyclic loading on the physical and mechanical properties of pultruded glass fiber reinforced polymer (GFRP) square tubes used in civil engineering structural applications. Most laboratory researches have focused mainly on the effect of elevated temperature on the compressive strength of the GFRP square tubes. Limited research has focused on the tensile strength of GFRP coupons under elevated temperatures. Dynamic Mechanical Analyses (DMA) was performed to assess the viscoelastic behavior including the glass transition temperature of GFRP. Sixteen GFRP coupons were tested under elevated temperatures to investigate the tensile strength and the effect of elevated temperatures to the tensile strength of GFRP. The results of an experimental program performed on fifty GFRP square tubes with different designs in 1.83m at normal temperatures were discussed to investigate compression performance. Another experimental program was performed on 20 GFRP square tubes with different designs in 1.22m under elevated temperatures. The experiments results were discussed and showed that the compressive strength of GFRP material was influenced by several factors including the glass transition v temperature and the connection bolts. Failure modes under 25°C and 75°C were crushing and the failure modes with the temperatures above 75°C were not typical crushing due to the glass transition of GFRP. Sixteen GFRP square tubes with length of 0.61m were tested with the same experimental program under elevated temperatures as the control group. Twelve GFRP square tubes with the same size were subjected to cyclic loading under elevated temperatures to investigate the effect of the cyclic loading to the compression properties of GFRP material. According to the experimental results and the discussion, the stiffness was reduced by the cyclic loading. On the contrary, the influence of the cyclic loading was not obvious compared to the GFRP specimens subjected to normal displacement control loading. The higher temperature made the stiffness of GFRP more sensitive to the cyclic loading.

  1. Applicability of laboratory experimental data (solubilities and sorption coefficients) to natural aquifier systems, for example, the Gorleben aquifer system

    International Nuclear Information System (INIS)

    The main objective of the research project is to elucidate the migration behaviour of long-lived radionuclides, especially actinides and technetium, in natural aquifer systems. Particular emphasis is directed to answer the question whether or not the experimental data obtained in laboratory can be applied without restriction to natural aquifer systems. For this purpose, the Gorleben aquifer system is taken as an example. As the subject encompasses a wide variety of geochemical reactions of long-lived radionuclides of divers elements, experiments have been confined to notable examples selected with regard to chemical nature of each element. Common reactions of geochemical importance, which are not well or poorly understood in the literature, are given priority in the present investigation. Laboratory experiments have been conducted on hydrolysis, carbonate complexation, humate complexation, redox reaction and colloid generation. Column experiments were performed for the elucidation of the migration behaviour of colloid-borne actinides. The applicability of laboratory data has been examined by comparison of thermodynamic speciation with direct spectroscopic speciation for given actinides in natural aquatic solution. Whenever the colloid generation is involved, either formation of 'real' or 'pseudo' colloids, the application of thermodynamic speciation becomes failed. In this case a new approach to appraisal of the actinide migration behaviour appears indispensable. This fact has aspired us to develop a novel method for the quantification of aquatic colloids of nanosize (10-100 nm) in very dilute concentrations (ppt range). (orig.)

  2. Theoretical and experimental investigation of thermohydrologic processes in a partially saturated, fractured porous medium

    International Nuclear Information System (INIS)

    The performance of a geologic repository for high-level nuclear waste will be influenced to a large degree by thermohydrologic phenomena created by the emplacement of heat-generating radioactive waste. The importance of these phenomena is manifest in that they can greatly affect the movement of moisture and the resulting transport of radionuclides from the repository. Thus, these phenomena must be well understood prior to a definitive assessment of a potential repository site. An investigation has been undertaken along three separate avenues of analysis: (i) laboratory experiments, (ii) mathematical models, and (iii) similitude analysis. A summary of accomplishments to date is as follows. (1) A review of the literature on the theory of heat and mass transfer in partially saturated porous medium. (2) A development of the governing conservation and constitutive equations. (3) A development of a dimensionless form of the governing equations. (4) A numerical study of the importance and sensitivity of flow to a set of dimensionless groups. (5) A survey and evaluation of experimental measurement techniques. (6) Execution of laboratory experiments of nonisothermal flow in a porous medium with a simulated fracture

  3. An experimental investigation into the mechanisms of bacterial evolution

    Science.gov (United States)

    Wee Sit, Liezl Nicolette S.

    This research investigated a new additive manufacturing approach for the rapid and inexpensive fabrication of tooling with microstructured surfaces. In this process, a metal-filled paste is printed onto a substrate and then sintered. Therefore, the approach eliminates the step (layer) effect present in current additive manufacturing processes. Results showed that paste viscosity significantly affected feature uniformity, with higher viscosity pastes producing narrow lines and more uniform feature heights. Printing parameters (print head type, flow rate from the print head, tip gap, tip diameter, and printing speed) were investigated as controls for microfeature height and width. Paste formulation was critical parameters for producing features with uniform cross-sections. The minimum feature dimensions achieved were 324 microm line width. Since the novel tooling was undamaged after 5000 injection molding cycles a new injection mold was designed and fabricated for this tooling (which is an insert).

  4. Experimental investigation on heat transport in gravel-sand materials

    DEFF Research Database (Denmark)

    Maureschat, Gerald; Heller, Alfred

    1997-01-01

    The project is a basic study on the expected thermal behaviour of gravel storage initiated as a part of a research and demonstration gravel storage for seasonal heat storage.The goal of the investigation is to determine the heat transfer between heat pipes and sand-gravel storage media by carrying...... out in a small size experiment. The experiment consists of a highly insulated box filled with two kinds of sand material crossed by a plastic heat pipe. Heat transfer is measured under dry and water satured conditions in a cross-section.The conclusions are clear. To obtain necessary heat conduction in...... media no convectional heat transport is found. It would be relevant to extend the investigation to media that enables convectional heat transport. A last conclusion is that such experiments, necessary for proper designing of sand-gravel storage types, are a very cheap form of collecting information...

  5. Exploratory experimental investigations on post-tensioned structural glass beams

    DEFF Research Database (Denmark)

    Louter, C.; Nielsen, Jens Henrik

    2013-01-01

    This paper discusses two projects on post-tensioned glass beams, performed at EPFL and DTU, respectively. In these projects small scale glass beams (length of 1.5m and 1m) are post-tensioned by means of steel threaded rods tensioned at the beam ends. The purpose of post-tensioning glass beams is to enhance the initial failure stress of the glass and to obtain ductile (post-breakage) performance. From four-point bending tests on the post-tensioned glass beam specimens it is observed that these goals are reached. From the test results it is concluded that post-tensioning glass beams is a feasible and promising concept, which provides enhanced strength and ductile (post-breakage) performance. Since the current investigations are exploratory, the investigated concepts leave unsolved challenges for future research within this field.

  6. Experimental Investigation on Mechanical Properties of Ilmenite based Al Nanocomposites

    Directory of Open Access Journals (Sweden)

    L. Rasidhar

    2013-05-01

    Full Text Available In the present investigation an attempt is made to fabricate Aluminium based metal matrix nanocomposite with Ilmenite nanoparticles. Nanocomposite is fabricated with different weight fractions (1,2,3,4,5% of Ilmenite nanoparticles. Microstructure of fabricated composite shows the uniform distribution of nano particles, density and hardness tests were performed for different weight fraction reinforcement .The mechanical properties like hardness and density increases with the increase of percentage of reinforcement of nano ilmenite particles.

  7. Yorkshire Assimilation: An Experimental Investigation of Gradient Phonological Alternation

    OpenAIRE

    Zee, T.J.

    2015-01-01

    This thesis investigates Yorkshire Assimilation (YA) in relation to both the phonology-phonetics and the categoricality-gradience distinction. Importantly, it is not assumed that the distinction between phonology and phonetics is based on that between categoricality and gradience. Firstly, regarding the phonology-phonetics distinction, it is argued on articulatory phonetic grounds that if YA is cued by segmental duration, this must be the result of a phonological process. Secondly, regarding ...

  8. Grandiose delusions: an experimental investigation of the delusion as defense.

    OpenAIRE

    Smith, N.; Freeman, D.; Kuipers, E.

    2005-01-01

    Two distinct roles for emotion in the development of delusions have been outlined. Some authors argue that delusions defend against low self-esteem and negative emotion (the delusion-as-defense account). Other authors hypothesize that delusions are not a defense but are a direct reflection of emotion and associated processes (the emotion-consistent account). An empirical investigation was conducted of the delusion-as-defense account with reference to grandiose delusions. Twenty individuals wi...

  9. Sensorimotor incongruence and body perception: an experimental investigation

    OpenAIRE

    JensFoell; HertaFlor; CandidaS.McCabe

    2013-01-01

    Objectives: Several studies have shown that mirrored arm or leg movements are related to altered body sensations. This includes the alleviation of chronic pain using congruent mirror feedback and the induction of abnormal sensation in healthy participants using incongruent mirror feedback. Prior research has identified neuronal and conceptual mechanisms of these phenomena. With the rising application of behavior-based methods for pain relief, a structured investigation of these reported effec...

  10. Experimental investigation of DC gas breakdown in argon

    International Nuclear Information System (INIS)

    In this paper the DC gas breakdown in argon have been investigated at the different interelectrode gaps L and the discharge tube radius R. The modified Paschen law have been obtained Udc = f (pL, L/R), that is the DC breakdown voltage Udc is the function not only product of the gas pressure p and the interelectrode gap L, but also the function of the ratio L/R

  11. Sensorimotor Incongruence and Body Perception: An Experimental Investigation

    OpenAIRE

    Foell, Jens; Bekrater-Bodmann, Robin; McCabe, Candida S; Flor, Herta

    2013-01-01

    Objectives: Several studies have shown that mirrored arm or leg movements can induce altered body sensations. This includes the alleviation of chronic pain using congruent mirror feedback and the induction of abnormal sensation in healthy participants using incongruent mirror feedback. Prior research has identified neuronal and conceptual mechanisms of these phenomena. With the rising application of behavior-based methods for pain relief, a structured investigation of these reported effects s...

  12. Experimental investigation of liquid chromatography columns by means of computed tomography

    DEFF Research Database (Denmark)

    Astrath, D.U.; Lottes, F.; Vu, Duc Thuong; Arlt, W.; Stenby, Erling Halfdan

    2007-01-01

    The efficiency of packed chromatographic columns was investigated experimentally by means of computed tomography (CT) techniques. The measurements were carried out by monitoring tracer fronts in situ inside the chromatographic columns. The experimental results were fitted using the equilibrium di...

  13. Cold Climate Foundation Retrofit Experimental Hygrothermal Performance: Cloquet Residential Research Facility Laboratory Results

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Louise F. [NorthernSTAR, St. Paul, MN (United States); Harmon, Anna C. [NorthernSTAR, St. Paul, MN (United States)

    2015-04-01

    Thermal and moisture problems in existing basements create a unique challenge because the exterior face of the wall is not easily or inexpensively accessible. This approach addresses thermal and moisture management from the interior face of the wall without disturbing the exterior soil and landscaping. the interior and exterior environments. This approach has the potential for improving durability, comfort, and indoor air quality. This project was funded jointly by the National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL). ORNL focused on developing a full basement wall system experimental database to enable others to validate hygrothermal simulation codes. NREL focused on testing the moisture durability of practical basement wall interior insulation retrofit solutions for cold climates. The project has produced a physically credible and reliable long-term hygrothermal performance database for retrofit foundation wall insulation systems in zone 6 and 7 climates that are fully compliant with the performance criteria in the 2009 Minnesota Energy Code. The experimental data were configured into a standard format that can be published online and that is compatible with standard commercially available spreadsheet and database software.

  14. Experimental investigation of colloidal and microbiological effect for geological disposal

    International Nuclear Information System (INIS)

    In order to know the characteristics of nuclide transfer in bentonites, which are taking attraction as a buffering material it seems essential to clarify the structure of compressed bentonites. Since the movements of various colloids and microorganisms in bentonite are greatly influenced by its pore size, the size is thought to be closely related to the transfer of nuclides in it. In this study, the effects of pore size were investigated in respect of the permeabilities for microorganisms and colloids. Gold colloids (grain size; 15 mm) were not transferred in a compressed bentonite with dry density of 1000 kg/m3, whereas those were permeable to the bentonite mixed with silica sand at 50% (w/w) for the dry density of 1000 kg/m3 but not permeable to that for 1800 kg/m3. Microbial resistance of compressed bentonite was studied in a deep geologic environment. The growths of sulfate-reducing bacteria and methane-producing bacteria were investigated in a fermenter, showing that the environment similar to actual conditions for geological disposal is habitable for these bacteria. But, it is assumed these bacteria larger than the gold colloid can not move in the environment. Therefore, it seems necessary in future to investigate bacterial effects outside of the bentonite. (M.N.)

  15. Experimental investigation of ion-ion recombination under atmospheric conditions

    Science.gov (United States)

    Franchin, A.; Ehrhart, S.; Leppä, J.; Nieminen, T.; Gagné, S.; Schobesberger, S.; Wimmer, D.; Duplissy, J.; Riccobono, F.; Dunne, E. M.; Rondo, L.; Downard, A.; Bianchi, F.; Kupc, A.; Tsagkogeorgas, G.; Lehtipalo, K.; Manninen, H. E.; Almeida, J.; Amorim, A.; Wagner, P. E.; Hansel, A.; Kirkby, J.; Kürten, A.; Donahue, N. M.; Makhmutov, V.; Mathot, S.; Metzger, A.; Petäjä, T.; Schnitzhofer, R.; Sipilä, M.; Stozhkov, Y.; Tomé, A.; Kerminen, V.-M.; Carslaw, K.; Curtius, J.; Baltensperger, U.; Kulmala, M.

    2015-07-01

    We present the results of laboratory measurements of the ion-ion recombination coefficient at different temperatures, relative humidities and concentrations of ozone and sulfur dioxide. The experiments were carried out using the Cosmics Leaving OUtdoor Droplets (CLOUD) chamber at CERN, the walls of which are made of conductive material, making it possible to measure small ions. We produced ions in the chamber using a 3.5 GeV c-1 beam of positively charged pions (?+) generated by the CERN Proton Synchrotron (PS). When the PS was switched off, galactic cosmic rays were the only ionization source in the chamber. The range of the ion production rate varied from 2 to 100 cm-3 s-1, covering the typical range of ionization throughout the troposphere. The temperature ranged from -55 to 20 °C, the relative humidity (RH) from 0 to 70 %, the SO2 concentration from 0 to 40 ppb, and the ozone concentration from 200 to 700 ppb. The best agreement of the retrieved ion-ion recombination coefficient with the commonly used literature value of 1.6 × 10-6 cm3 s-1 was found at a temperature of 5 °C and a RH of 40 % (1.5 ± 0.6) × 10-6 cm3 s-1. At 20 °C and 40 % RH, the retrieved ion-ion recombination coefficient was instead (2.3 ± 0.7) × 10-6 cm3 s-1. We observed no dependency of the ion-ion recombination coefficient on ozone concentration and a weak variation with sulfur dioxide concentration. However, we observed a more than fourfold increase in the ion-ion recombination coefficient with decreasing temperature. We compared our results with three different models and found an overall agreement for temperatures above 0 °C, but a disagreement at lower temperatures. We observed a strong increase in the recombination coefficient for decreasing relative humidities, which has not been reported previously.

  16. Experimental investigation of ion-ion recombination at atmospheric conditions

    Directory of Open Access Journals (Sweden)

    A. Franchin

    2015-02-01

    Full Text Available We present the results of laboratory measurements of the ion-ion recombination coefficient at different temperatures, relative humidities and concentrations of ozone and sulfur dioxide. The experiments were carried out using the Cosmics Leaving OUtdoor Droplets (CLOUD chamber at CERN, the walls of which are made of conductive material, making it possible to measure small ions. We produced ions in the chamber using a 3.5 GeV c?1 beam of positively-charged pions (?+ from the CERN Proton Synchrotron (PS and with galactic cosmic rays, when the PS was switched off. The range of the ion production rate varied from 2 to 100 cm?3s?1, covering the typical range of ionization throughout the troposphere. The temperature ranged from ?55 to 20 °C, the relative humidity from 0 to 70%, the SO2 concentration from 0 to 40 ppb, and the ozone concentration from 200 to 700 ppb. At 20 °C and 40% RH, the retrieved ion-ion recombination coefficient was (2.3 ± 0.7 × 10?6cm3s?1. We observed no dependency of the ion-ion recombination coefficient on ozone concentration and a weak variation with sulfur dioxide concentration. However, we found a strong dependency of the ion-ion recombination coefficient on temperature. We compared our results with three different models and found an overall agreement for temperatures above 0 °C, but a disagreement at lower temperatures. We observed a strong dependency of the recombination coefficient on relative humidity, which has not been reported previously.

  17. Experimental and numerical investigation of HyperVapotron heat transfer

    International Nuclear Information System (INIS)

    The divertor first wall and neutral beam injection (NBI) components of tokamak devices require high heat flux removal up to 20–30 MW m?2 for future fusion reactors. The water cooled HyperVapotron (HV) structure, which relies on internal grooves or fins and boiling heat transfer to maximize the heat transfer capability, is the most promising candidate. The HV devices, that are able to transfer large amounts of heat (1–20 MW m?2) efficiently, have therefore been developed specifically for this application. Until recently, there have been few attempts to observe the detailed bubble characteristics and vortex evolvement of coolant flowing inside their various parts and understand of the internal two-phase complex heat transfer mechanism behind the vapotron effect. This research builds the experimental facilities of HyperVapotron Loop-I (HVL-I) and Pressure Water HyperVapotron Loop-II (PWHL-II) to implement the subcooled boiling principle experiment in terms of typical flow parameters, geometrical parameters of test section and surface heat flux, which are similar to those of the ITER-like first wall and NBI components (EAST and MAST). The multiphase flow and heat transfer phenomena on the surface of grooves and triangular fins when the subcooled water flowed through were observed and measured with the planar laser induced fluorescence (PLIF) and high-speed photography (HSP) techniques. Particle image velocimetry (PIV) was selected to reveal vortex formation, the flow structure that promotes the vapotron effect during subcooled boiling. The coolant flow data for contributing to the understanding of the vapotron phenomenon and the assessment of how the design and operational conditions that might affect the thermal performance of the devices were collected and analysed. The subcooled flow boiling model and methods of HV heat transfer adopted in the considered computational fluid dynamics (CFD) code were evaluated by comparing the calculated wall temperatures with the experimentally measured values. It was discovered that the bubble and vortex characteristics in the HV are clearly heavily dependent on the internal geometry, flow conditions and input heat flux. The evaporation latent heat is the primary heat transfer mechanism of HV flow under the condition of high heat flux, and the heat transfer through convection is very limited. The percentage of wall heat flux going into vapour production is almost 70%. These relationships between the flow phenomena and thermal performance of the HV device are essential to study the mechanisms for the flow structure alterations for design optimization and improvements of the ITER-like devices' water cooling structure and plasma facing components for future fusion reactors. (paper)

  18. Experimental and numerical investigation of HyperVapotron heat transfer

    Science.gov (United States)

    Wang, Weihua; Deng, Haifei; Huang, Shenghong; Chu, Delin; Yang, Bin; Mei, Luoqin; Pan, Baoguo

    2014-12-01

    The divertor first wall and neutral beam injection (NBI) components of tokamak devices require high heat flux removal up to 20-30 MW m-2 for future fusion reactors. The water cooled HyperVapotron (HV) structure, which relies on internal grooves or fins and boiling heat transfer to maximize the heat transfer capability, is the most promising candidate. The HV devices, that are able to transfer large amounts of heat (1-20 MW m-2) efficiently, have therefore been developed specifically for this application. Until recently, there have been few attempts to observe the detailed bubble characteristics and vortex evolvement of coolant flowing inside their various parts and understand of the internal two-phase complex heat transfer mechanism behind the vapotron effect. This research builds the experimental facilities of HyperVapotron Loop-I (HVL-I) and Pressure Water HyperVapotron Loop-II (PWHL-II) to implement the subcooled boiling principle experiment in terms of typical flow parameters, geometrical parameters of test section and surface heat flux, which are similar to those of the ITER-like first wall and NBI components (EAST and MAST). The multiphase flow and heat transfer phenomena on the surface of grooves and triangular fins when the subcooled water flowed through were observed and measured with the planar laser induced fluorescence (PLIF) and high-speed photography (HSP) techniques. Particle image velocimetry (PIV) was selected to reveal vortex formation, the flow structure that promotes the vapotron effect during subcooled boiling. The coolant flow data for contributing to the understanding of the vapotron phenomenon and the assessment of how the design and operational conditions that might affect the thermal performance of the devices were collected and analysed. The subcooled flow boiling model and methods of HV heat transfer adopted in the considered computational fluid dynamics (CFD) code were evaluated by comparing the calculated wall temperatures with the experimentally measured values. It was discovered that the bubble and vortex characteristics in the HV are clearly heavily dependent on the internal geometry, flow conditions and input heat flux. The evaporation latent heat is the primary heat transfer mechanism of HV flow under the condition of high heat flux, and the heat transfer through convection is very limited. The percentage of wall heat flux going into vapour production is almost 70%. These relationships between the flow phenomena and thermal performance of the HV device are essential to study the mechanisms for the flow structure alterations for design optimization and improvements of the ITER-like devices' water cooling structure and plasma facing components for future fusion reactors.

  19. Combine experimental and theoretical investigation on an alkaloid-Dimethylisoborreverine

    Science.gov (United States)

    Singh, Swapnil; Singh, Harshita; Karthick, T.; Agarwal, Parag; Erande, Rohan D.; Dethe, Dattatraya H.; Tandon, Poonam

    2016-01-01

    A combined experimental (FT-IR, 1H and 13C NMR) and theoretical approach is used to study the structure and properties of antimalarial drug dimethylisoborreverine (DMIB). Conformational analysis, has been performed by plotting one dimensional potential energy curve that was computed using density functional theory (DFT) with B3LYP/6-31G method and predicted conformer A1 as the most stable conformer. After full geometry optimization, harmonic wavenumbers were computed for conformer A1 at the DFT/B3LYP/6-311++G(d,P) level. A complete vibrational assignment of all the vibrational modes have been performed on the bases of the potential energy distribution (PED) and theoretical results were found to be in good agreement with the observed data. To predict the solvent effect, the UV-Vis spectra were calculated in different solvents by polarizable continuum model using TD-DFT method. Molecular docking studies were performed to test the biological activity of the sample using SWISSDOCK web server and Hex 8.0.0 software. The molecular electrostatic potential (MESP) was plotted to identify the reactive sites of the molecule. Natural bond orbital (NBO) analysis was performed to get a deep insight of intramolecular charge transfer. Thermodynamical parameters were calculated to predict the direction of chemical reaction.

  20. Theoretical and experimental investigations of polarization switching in ferroelectric materials

    Science.gov (United States)

    Picinin, A.; Lente, M. H.; Eiras, J. A.; Rino, J. P.

    2004-02-01

    The polarization switching process is certainly the most important feature of ferroelectric materials from fundamental as well as practical points of view. In this paper, a one-dimensional lattice model is presented in order to describe the polarization switching process in ferroelectric materials, incorporating the contribution of both dipolar defects and depolarizing fields to the domain reorientation. The influence of the interaction strength between switchable dipoles and dipolar defects, the medium viscosity, the depolarizing fields, and the frequency of the external electric field on the polarization switching were simulated. It was found that the degree of interaction between domains and dipolar defects has a strong influence on the coercive field, polarization, and backswitching behavior. Through an adequate analysis of the variables in the model it was also possible to describe the evolution of the polarization switching with the number of electric field cycles, which is commonly observed in the fatigue or depinning process. Comparison between simulated and experimental results revealed a remarkable concordance.

  1. Experimental investigation on ejecting low-temperature cooling superconducting magnets

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bin; Zhang, Qiang, E-mail: 6266798@qq.com; Tong, Ming-wei; Hu, Peng; Wu, Shuang-ying; Cai, Qin; Qin, Zeng-hu

    2013-10-15

    Highlights: • The cooling temperature of the superconducting materials can be adjusted by the ejecting refrigeration. • The result shows that the temperature of liquid nitrogen can be reduced to 70 K by controlling the inlet water pressure of the ejector. • The refrigeration performance of ejector is affected by the different structure and system pressure. -- Abstract: With the development of the high-temperature superconducting (HTS) materials and refrigeration technologies, using ejecting refrigeration to cool the superconducting materials becomes the direction of HTS applications. In this paper, an experimental study has been carried out on the basis of the theory of analyzing the ejecting low-temperature cooling superconducting magnet. The relationship between area ratios and refrigeration performance at different system pressures was derived. In addition, the working fluid flow and suction chamber pressure of the ejector with different area ratios at various inlet pressures have been examined to obtain the performance of ejectors under different working conditions. The result shows that the temperature of liquid nitrogen can be reduced to 70 K by controlling the inlet water pressure when the pressurized water at 20 °C is used to eject the saturated liquid nitrogen, which can provide the stable operational conditions for the HTS magnets cooling.

  2. Experimental investigations of micro air injection to control rotating stall

    Science.gov (United States)

    Nie, Chaoqun; Tong, Zhiting; Geng, Shaojuan; Zhu, Junqiang; Huang, Weiguang

    2007-03-01

    Steady discrete micro air injection at the tip region in front of the first compressor rotor has been proved to be an effective method to delay the inception of rotating stall in a low speed axial compressor. Considering the practical application a new type of micro injector was designed and described in this paper, which was imbedded in the casing and could be moved along the chord. In order to verify its feasibility to other cases, such as high subsonic axial compressor or centrifugal compressor, some other cases have been studied. Experimental results of the same low speed axial compressor showed that the new injector could possess many other advantages besides successfully stabilizing the compressor. Experiments performed on a high subsonic axial compressor confirmed the effectiveness of micro air injection when the relative velocity at the blade tip is high subsonic. Meanwhile in order to explore its feasibility in centrifugal compressor, a similar micro injector was designed and tested on a low speed centrifugal compressor with vaned diffuser. The injected mass flow was a bit larger than that used in axial compressors and the results showed micro injection could also delay the onset of rotating stall in the centrifugal compressor.

  3. Experimental Investigation of Moisture Driven Fracture in Solid Wood

    DEFF Research Database (Denmark)

    Larsen, Finn; Ormarsson, Sigurdur

    2010-01-01

    Solid timber products, containing both heartwood and sapwood, often have a high tendency to crack during the drying process. This can cause severe loss of material for the saw-mills, especially for products with large cross sectional dimensions. The cracks (e.g. end-cracks) arise, in some cases, early in the drying process and close again later in the process. It can be difficult to see the closed cracks with visual grading. This may result in too high grading of the damaged material which may cause problems for customers such as building and furniture industries. Moisture content (MC) in green wood varies within the cross section of a timber log. The MC of heartwood, for example, is considerable lower than the MC of sapwood. Shrinkage starts at different times within different parts of the cross section, which results in a complex state of strains and stresses. The moisture related crack pattern in wood often becomes quite complex because of the annual ring structure and the different MC levels within heartwood and sapwood. The focus of this work represents the cross sectional behaviour of a timber log. The main aim is to accumulate experimental results and data for the development of a finite element model to evaluate the various couplings in the hygro-mechanical problem that govern moisture driven cracking in wood.

  4. Experimental Investigation of Catastrophic Cover-collapse Sinkhole Formation

    Science.gov (United States)

    Tao, X.; Wang, D.; Ye, M.; Wang, X.; Zhao, J.; Pacheco Castro, R. B.

    2014-12-01

    Cover-collapse sinkholes develop abruptly and can lead catastrophic damages. In order to study the mechanism of cover-collapse sinkhole formation, we set up a two dimensional experimental model and analyze the critical conditions of soil cavity expansion and collapse and discuss the role of the seepage force in the formation of sinkhole. A forecasting model of sinkhole collapse coupled the mechanics and flow is established in which a critical dimensionless number was used to evaluate the sinkhole development. The results show that: The impact of hydrologic conditions on the cave expanding is generally dramatic and geology (the scale of the opening, soil property, thickness of soil layer, etc.) plays a critical role in sinkhole development. The weak opening of the limestone by karst processes under the clay layer is the essential condition which can cause an arch in clay immediately; due to downward seepage force, the arch develops into soil cave which would expand upward stage by stage as a result of failure of soil. A short false stability exists between two contiguous stages until the arch of the soil cave cannot support the soil roof and then the sinkhole collapses. Moreover during the process the cohesive force of the soil is the major resisting force of sinkhole development.

  5. Experimental investigation on a high subsonic compressor cascade flow

    Directory of Open Access Journals (Sweden)

    Zhang Haideng

    2015-08-01

    Full Text Available With the aim of deepening the understanding of high-speed compressor cascade flow, this paper reports an experimental study on NACA-65 K48 compressor cascade with high subsonic inlet flow. With the increase of passage pressurizing ability, endwall boundary layer behavior is deteriorated, and the transition zone is extended from suction surface to the endwall as the adverse pressure gradient increases. Cross flow from endwall to midspan, mixing of corner boundary layer and the main stream, and reversal flow on the suction surface are caused by corner separation vortex structures. Passage vortex is the main corner separation vortex. During its movement downstream, the size grows bigger while the rotating direction changes, forming a limiting circle. With higher incidence, corner separation is further deteriorated, leading to higher flow loss. Meanwhile, corner separation structure, flow mixing characteristics and flow loss distribution vary a lot with the change of incidence. Compared with low aspect-ratio model, corner separation of high aspect-ratio model moves away from the endwall and is more sufficiently developed downstream the cascade. Results obtained present details of high-speed compressor cascade flow, which is rare in the relating research fields and is beneficial to mechanism analysis, aerodynamic optimization and flow control design.

  6. Experimental investigation on ejecting low-temperature cooling superconducting magnets

    International Nuclear Information System (INIS)

    Highlights: • The cooling temperature of the superconducting materials can be adjusted by the ejecting refrigeration. • The result shows that the temperature of liquid nitrogen can be reduced to 70 K by controlling the inlet water pressure of the ejector. • The refrigeration performance of ejector is affected by the different structure and system pressure. -- Abstract: With the development of the high-temperature superconducting (HTS) materials and refrigeration technologies, using ejecting refrigeration to cool the superconducting materials becomes the direction of HTS applications. In this paper, an experimental study has been carried out on the basis of the theory of analyzing the ejecting low-temperature cooling superconducting magnet. The relationship between area ratios and refrigeration performance at different system pressures was derived. In addition, the working fluid flow and suction chamber pressure of the ejector with different area ratios at various inlet pressures have been examined to obtain the performance of ejectors under different working conditions. The result shows that the temperature of liquid nitrogen can be reduced to 70 K by controlling the inlet water pressure when the pressurized water at 20 °C is used to eject the saturated liquid nitrogen, which can provide the stable operational conditions for the HTS magnets cooling

  7. Experimental Investigation of NO from Pulverized Char Combustion

    DEFF Research Database (Denmark)

    Jensen, Lars Skaarup; Jannerup, Hans Erik; Glarborg, Peter; Jensen, Anker; Dam-Johansen, Kim

    2001-01-01

    NO formation and reduction during pulverized char combustion in the temperature range 850–1150°C have been investigated in fixed-bed combustion experiments. Chars from a high-volatile bituminous coal and an anthracite have been used. Under single-particle conditions the selectivity for NO formation...... pulverized bituminous coal char in the temperature range 850–1150 °C has been found to be given by rNO=6?106m3kgC?s?e14800/T(K)?[charC]?[NO]...

  8. A preliminary experimental investigation into lateral pedestrian-structure interaction

    DEFF Research Database (Denmark)

    Ingólfsson, Einar Thór; Georgakis, Christos; Knudsen, Anders

    2008-01-01

    of 17 m and weight of 19.6 ton, the platform provides a realistic comparison to an actual footbridge. Based on experiments with single pedestrians walking across the platform at resonance, the fundamental dynamic load factor is determined using only the recorded acceleration signal. Furthermore......, tests were made with small groups of people to investigate their tendency to synchronise their walking to the motion of the platform. By analysing the recorded acceleration response and video data from the tests, the pedestrian pacing rate distribution and correlated pedestrian force have been...

  9. Experimental investigation of a newly designed supersonic wind tunnel

    Science.gov (United States)

    Wu, J.; Radespiel, R.

    2015-06-01

    The flow characteristics of the tandem nozzle supersonic wind tunnel at the Institute of Fluid Mechanics, Technische Universität Braunschweig, a are investigated. Conventional measurement techniques were utilized. The flow development is examined by pressure sensors installed at various streamwise positions. The temperature is measured in the storage tube and the settling chamber. The influence of flow treatment in the settling chamber on the flow quality is also studied. The flow quality of test section is evaluated by a 6-probe Pitot rake. The pressure fluctuations in the test section are studied by a sharp cone model. Eventually, good agreement between the measurements and numerical simulation of the tunnel design is achieved.

  10. Experimental investigation of the crashworthiness of scaled composite sailplane fuselages

    Science.gov (United States)

    Kampf, Karl-Peter; Crawley, Edward F.; Hansman, R. John, Jr.

    1989-01-01

    The crash dynamics and energy absorption of composite sailplane fuselage segments undergoing nose-down impact were investigated. More than 10 quarter-scale structurally similar test articles, typical of high-performance sailplane designs, were tested. Fuselages segments were fabricated of combinations of fiberglass, graphite, Kevlar, and Spectra fabric materials. Quasistatic and dynamic tests were conducted. The quasistatic tests were found to replicate the strain history and failure modes observed in the dynamic tests. Failure modes of the quarter-scale model were qualitatively compared with full-scale crash evidence and quantitatively compared with current design criteria. By combining material and structural improvements, substantial increases in crashworthiness were demonstrated.

  11. A Laboratory Course for Teaching Laboratory Techniques, Experimental Design, Statistical Analysis, and Peer Review Process to Undergraduate Science Students

    Science.gov (United States)

    Gliddon, C. M.; Rosengren, R. J.

    2012-01-01

    This article describes a 13-week laboratory course called Human Toxicology taught at the University of Otago, New Zealand. This course used a guided inquiry based laboratory coupled with formative assessment and collaborative learning to develop in undergraduate students the skills of problem solving/critical thinking, data interpretation and…

  12. Protocol for further laboratory investigations into the distribution of infectivity of Atypical BSE

    OpenAIRE

    European Food Safety Authority

    2014-01-01

    Information on the pathogenesis and tissue distribution of Atypical Bovine Spongiform Encephalopathy (BSE) in cattle through the study of field cases and experimental transmission studies is lacking. The latter are limited to transmission of Atypical BSE through intracerebral (i.c.) inoculation of cattle. All data currently available relate to the presence or absence of PrPSc, but do not quantify relative amounts of PrPSc or levels of infectivity. A laboratory protocol for further studies is ...

  13. Experimental investigation of stepped solar still with continuous water circulation

    International Nuclear Information System (INIS)

    Highlights: • Comparison between modified stepped and conventional solar still was carried out. • Effect of storage tank and cotton absorber on productivity was investigated. • Efficiency for modified stepped still is higher than conventional still by 20%. • The day and night efficiency increases by 5% and 3.5% for salt and sea water. - Abstract: This paper presents a modification of stepped solar still with continuous water circulation using a storage tank for sea and salt water. Total dissolved solids (TDS) of seawater and salt water before desalination is 57,100 and 2370 mg/l. A comparison study between modified stepped and conventional solar still was carried out to evaluate the developed desalination system performance under the same climate conditions. The effect of installing a storage tank and cotton black absorber for modified stepped solar still on the distillate productivity was investigated. The results indicate that, the productivity of the modified stepped still is higher than that for conventional still approximately by 43% and 48% for sea and salt water with black absorber respectively, while 53% and 47% of sea and salt water, respectively with cotton absorber. Also, the daily efficiency for modified stepped still is higher than that for conventional still approximately by 20%. The maximum efficiency of modified stepped still is occurring at a feed water flow rate of 1 LPM for sea water and 3 LPM for salt water. Total dissolved solids (TDS) of seawater and salt water after desalination is 41, and 27 mg/l

  14. Sensorimotor Incongruence and Body Perception: An Experimental Investigation

    Science.gov (United States)

    Foell, Jens; Bekrater-Bodmann, Robin; McCabe, Candida S.; Flor, Herta

    2013-01-01

    Objectives: Several studies have shown that mirrored arm or leg movements can induce altered body sensations. This includes the alleviation of chronic pain using congruent mirror feedback and the induction of abnormal sensation in healthy participants using incongruent mirror feedback. Prior research has identified neuronal and conceptual mechanisms of these phenomena. With the rising application of behavior-based methods for pain relief, a structured investigation of these reported effects seems necessary. Methods: We investigated a mirror setup that included congruent and incongruent hand and arm movements in 113 healthy participants and assessed the occurrence and intensity of unusual physical experiences such as pain, the sensation of missing or additional limbs, or changes in weight or temperature. A wooden surface instead of a mirror condition served as control. Results: As reported earlier, mirrored movements led to a variety of subjective reactions in both the congruent and incongruent movement condition, with the sensation of possessing a third limb being significantly more intense and frequent in the incongruent mirror condition. Reports of illusory pain were not more frequent during mirrored than during non-mirrored movements. Conclusion: These results suggest that, while all mirrored hand movements induce abnormal body perceptions, the experience of an extra limb is most pronounced in the incongruent mirror movement condition. The frequent sensation of having a third arm may be related to brain processes designed to integrate input from several senses in a meaningful manner. Painful sensations are not more frequent or intense when a mirror is present. PMID:23805095

  15. An experimental investigation of Fang's Ag superlens suitable for integration

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Nielsen, Rasmus Bundgaard

    2009-01-01

    We report on experimental realization of the Fang Ag superlens structure [1] suitable for further processing and integration in bio-chips by replacing PMMA with a highly chemical resistant cyclo-olefin copolymer, mr-I T85 (Micro Resist Technology, Berlin, Germany). The superlens was able to resolve 80 nm half-pitch gratings when operating at a free space wavelength of 365 nm. Fang et al. used PMMA since it enables the presence of surface plasmons at the PMMA/Ag interface at 365 nm and because it planarizes the quartz/chrome mask. If the superlens is to be integrated into a device where further processing is needed involving various organic polar solvents, PMMA cannot be used. We propose to use mr-I T85, which is highly chemically resistant to acids and polar solvents. Our superlens stack consists of a quartz/chrome grating mask, a 40 nm layer of mr-I T85, 35 nm Ag, and finally 70 nm of the negative photoresist mr-UVL 6000 (Micro Resist). A 50 nm layer of aluminium on top of the quartz/chrome mask reflected all light that did not penetrate through the mask openings thereby reducing waveguiding in the top resist layer. The exposures took place in a UV-aligner at 365 nm corresponding to the excitation wavelength of the surface plasmons at the mr-I T85/Ag interface. Supporting COMSOL simulations illustrate the field intensity distribution inside the resist as well as the presence of surface plasmons at the mr-I T85/Ag boundary. AFM scans of the exposed structure revealed 80 nm gratings.

  16. Experimental Investigations of Vertical and Horizontal Heat Pipes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Guk; Kim, Kyuung Mo; Jeong, Young Shin; Bang, In Cheol [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2014-10-15

    The interest in the application of heat pipes for heat transfer system is well known in industrial fields. Heat pipe uses the working fluid in containment as cylindrical shape tube. Vaporization occurs in evaporation section due to the heat input and vapor is transferred to condensation section. At the condensation area, the working fluid is condensed and immersed in the wick structure, which has highly porous media. The condensed working fluid returns to evaporator section by capillary wicking of wick structure. The driving force for working fluid is affected by capillary and gravitational force. The heat pipes for nuclear systems have been suggested as horizontal loop heat pipes for reactor core cooling system or vertical heat pipes for passive cooling for spent fuel. In the present research, preliminary tests of horizontal and vertical heat pipe were studied for its heat transfer performance. The main purpose of the research was the analysis of heat transfer behavior of heat pipe and the performance of heat transfer. The thermal performances of horizontal and vertical heat pipe were measured experimentally. Vertical heat pipe showed better performance compared to horizontal one, at high heat input region. The heat transfer coefficients of horizontal heat pipe were lower than vertical one because of gravitational force. Overall heat transfer coefficient of vertical heat pipes were enhanced to 28.5 % compared to the horizontal heat pipes. The horizontal heat pipes revealed high thermal resistance up to 54.3 % compared to vertical heat pipes. Therefore, vertical heat pipes analyzed better heat transfer performance than horizontal heat pipe.

  17. Thought-shape fusion in anorexia nervosa: an experimental investigation.

    Science.gov (United States)

    Radomsky, Adam S; de Silva, Padmal; Todd, Gillian; Treasure, Janet; Murphy, Tara

    2002-10-01

    Cognitive biases and cognitive distortions have been implicated as important factors in the development and maintenance of many disorders. The concept of thought-shape fusion (TSF) in eating disorders was developed by Shafran, Teachman, Kerry, and Rachman (British Journal of Clinical Psychology 38 (1999) 167) as a variant of thought-action fusion, described by Shafran, Thordarson and Rachman (Journal of Anxiety Disorders 10 (1996) 379). TSF occurs when thinking about eating certain types of food increases a person's estimate of their shape and/or weight, elicits a perception of moral wrongdoing, and/or makes the person feel fat. Shafran et al. (1999) examined both the psychometric and experimental properties of TSF in an undergraduate sample. This paper reports an extension of this work to a clinical group (N=20) of patients with anorexia nervosa. After completing a set of relevant questionnaires, participants were asked to think about a food which they considered extremely fattening. They were then asked to write out the sentence, "I am eating--.", inserting the name of the fattening food in the blank. After being asked to rate their anxiety, guilt, feelings about their weight, morality, etc., participants were given the opportunity to neutralize their statement in any way they chose. The majority of the participants neutralized in ways consistent with the findings of Shafran et al. (1999). The results are discussed in terms of cognitive-behavioural formulations of eating disorders, and of the influence of cognitive biases and cognitive distortions on the processing of information relevant to food, weight and shape in anorexia nervosa. PMID:12375725

  18. Preparing side charging of PCM storage: theoretical and experimental investigation

    Science.gov (United States)

    Tesfay, A. H.; Hagos, F. Y.; Yohannes, K. G.; Nydal, O. J.; Kahsay, M. B.

    2015-12-01

    In Ethiopia, there is an abundant source of solar energy that is estimated to 5.3 kWh/m2/day. However, more than 90% of the society uses biomass as a main source of energy for cooking due to lack of technologies to convert this energy. Replacing these cooking activities by using renewable energy resources decreases pollution and reduces deforestation significantly. Using the solar energy in day time has no problem. For night time however, the system needs some kind of back-up system to make the daytime solar energy available. This back-up should have high-density energy storage and constant working temperature to perform a specific application. Latent heat storage using phase change materials (PCM) is one way of storing thermal energy. In the current study, a latent heat storage that uses a PCM material is used to store the solar energy aimed at utilizing solar energy for cooking Injera, main staple bread in Ethiopia. The PCM is a mixture of 60% NaNO3 and 40% KNO3 that are known as solar salts. The storage has a welded parallel aluminum fins with a gap of 40 mm in between to enhance the thermal conductivity during the charging-discharging process of the storage. The fins are extruded outside of the storage container to enable a side charging technique for the PCM. A prototype was developed with a solar salt of 17.5 kg and is tested for charging-discharging. The numerical simulation done on ANSYS and experimental results show an agreement and the system registered a 41.6% efficiency.

  19. Experimental Investigation of Shrinkage of Nano Hair Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Yadollah Batebi

    2013-01-01

    Full Text Available Basically most of cement based mixtures are likely shrinking. Use of fibers is not a new idea in this case. Previously, there were some evidences that horse hair, straw and cotton fibers were used in mud and mortars in ancient times. Then, utilizing these fibers in concrete mixture may increase concrete workability and decrease shrinkage cracks. Due to nano cross-section of hair and its proper tensile strength this project investigates its application to reduce the shrinkage of concrete mixtures. For this purpose, human hair fibers were used in 0.4 and 0.8 and 1.2 weight percent and the length of the fibers in each case varied between 15 and 60 millimeter and the samples were made of dimensions of 40×40×160 millimeters. Results are shown as considerable amount of hair may reduce in the shrinkage in the hair reinforced concrete.

  20. Experimental investigation of high energy pipe leak and rupture phenomena

    International Nuclear Information System (INIS)

    A series of high energy pipe leak and break experiments have been carried out to evaluate the criteria pertaining to postulated unstable pipe crack growth and opening under prototypical reactor operating conditions. Also investigated was leakage for pipes having subcritical crack conditions. It was the aim that through these tests, the current margin of pipe design against piping rupture loads can be quantified and the ''leak-before-break'' criterion can be further enhanced. The tests were performed on six-inch stainless steel and carbon steel pipes. Observed fracture behavior which interacts with the dynamic system conditions was evaluated with the perspective of the state of the art of ductile fracture mechanics, such as crack initiation, propagation, and arrest. The thermal-hydraulic transient phenomena and their influence of fracture are discussed. Directly affecting the piping system design is the jet reaction force. Preliminary evaluations using first principles were performed which show the influence of facility configuration and depressurization transient history