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

    Science.gov (United States)

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

    2011-12-01

    Geological storage of carbon dioxide in deep geologic formations is being considered as a technical option to reduce greenhouse gas loading to the atmosphere. The processes associated with the movement and stable trapping are complex in deep naturally heterogeneous formations. Three primary mechanisms contribute to trapping; capillary entrapment due to immobilization of the supercritical fluid CO2 within soil pores, liquid CO2 dissolving in the formation water and mineralization. Natural heterogeneity in the formation is expected to affect all three mechanisms. A research project is in progress with the primary goal to improve our understanding of capillary and dissolution trapping during injection and post-injection process, focusing on formation heterogeneity. It is expected that this improved knowledge will help to develop site characterization methods targeting on obtaining the most critical parameters that capture the heterogeneity to design strategies and schemes to maximize trapping. This research combines experiments at the laboratory scale with multiphase modeling to upscale relevant trapping processes to the field scale. This paper presents the results from a set of experiments that were conducted in an intermediate scale test tanks. Intermediate scale testing provides an attractive alternative to investigate these processes under controlled conditions in the laboratory. Conducting these types of experiments is highly challenging as methods have to be developed to extrapolate the data from experiments that are conducted under ambient laboratory conditions to high temperatures and pressures settings in deep geologic formations. We explored the use of a combination of surrogate fluids that have similar density, viscosity contrasts and analogous solubility and interfacial tension as supercritical CO2-brine in deep formations. The extrapolation approach involves the use of dimensionless numbers such as Capillary number (Ca) and the Bond number (Bo). A set of experiments that captures some of the complexities of the geologic heterogeneity and injection scenarios are planned in a 4.8 m long tank. To test the experimental methods and instrumentation, a set of preliminary experiments were conducted in a smaller tank with dimensions 90 cm x 60 cm. The tank was packed to represent both homogeneous and heterogeneous conditions. Using the surrogate fluids, different injection scenarios were tested. Images of the migration plume showed the critical role that heterogeneity plays in stable entrapment. Destructive sampling done at the end of the experiments provided data on the final saturation distributions. Preliminary analysis suggests the entrapment configuration is controlled by the large-scale heterogeneities as well as the pore-scale entrapment mechanisms. The data was used in modeling analysis that is presented in a companion abstract.

  3. Experimental investigation of the wake characteristics of flow-powered and motorized laboratory-scale wind turbines

    Science.gov (United States)

    Araya, Daniel; Dabiri, John

    2013-11-01

    We present experimental data that compares the wake characteristics of a laboratory-scale vertical-axis turbine while it is either powered by the flow or by a DC motor. This distinction is relevant for laboratory experiments in which scale turbine models are used that require the use of a motor to spin the turbine blades. Particle image velocimetry is used to measure the velocity field in a two-dimensional plane normal to the axis of rotation. This velocity field is then used to compare time-averaged streamwise velocity, turbulence kinetic energy, and power of the two configurations. The results give insight into the kinematic effect of adding energy to the flow by way of the motor, and they suggest limits on the extrapolation of laboratory results to full-scale performance. We present experimental data that compares the wake characteristics of a laboratory-scale vertical-axis turbine while it is either powered by the flow or by a DC motor. This distinction is relevant for laboratory experiments in which scale turbine models are used that require the use of a motor to spin the turbine blades. Particle image velocimetry is used to measure the velocity field in a two-dimensional plane normal to the axis of rotation. This velocity field is then used to compare time-averaged streamwise velocity, turbulence kinetic energy, and power of the two configurations. The results give insight into the kinematic effect of adding energy to the flow by way of the motor, and they suggest limits on the extrapolation of laboratory results to full-scale performance. This work was supported by an NSF Graduate Research Fellowship to D.B.A and funding to J.O.D. from ONR N000141211047.

  4. 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...

  5. 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

  6. The Hunterian Laboratory of Experimental Medicine.

    Science.gov (United States)

    Ro, Kevin; Cameron, John L; Yeh, Michael W

    2011-05-01

    The Hunterian Laboratory of Experimental Medicine, established at the Johns Hopkins Hospital in 1905, played a central role in the early history of American surgery. Created primarily by William Halsted with the help of Harvey Cushing, the Laboratory was a cornerstone of experimental surgical research as well as surgical education. This article examines the conception and early years of the Laboratory. PMID:21451394

  7. Laboratory Investigation of Primary Aldosteronism

    Science.gov (United States)

    Stowasser, Michael; Taylor, Paul J; Pimenta, Eduardo; Ahmed, Ashraf H Al-Asaly; Gordon, Richard D

    2010-01-01

    Availability and wider application of the plasma aldosterone/renin ratio (ARR) as a screening test for primary aldosteronism (PA) has led to the recognition that PA is the most common potentially curable and specifically treatable form of hypertension, possibly accounting for as many as 5–13% of patients. Aldosterone excess also has adverse cardiovascular consequences that go above and beyond hypertension development. These findings support the concept that PA plays an important role in cardiovascular disease states and should be systematically sought and specifically treated, and have led to the development of a US Endocrine Society clinical guideline for the detection, diagnosis and management of this condition. Reliable detection requires that interfering factors (including medications known to alter the ratio) are controlled before ARR measurement (or their effects taken into account), and reliable methods such as fludrocortisone suppression testing are used to confirm PA. Because computed tomography frequently misses aldosterone-producing adenomas yet demonstrates non-functioning nodules, adrenal venous sampling is the only dependable way to differentiate unilateral (surgically correctable) from bilateral (usually treated with aldosterone antagonist medications) forms of PA. For the glucocorticoid-remediable form of PA (familial hyperaldosteronism type I), genetic testing for the causative ‘hybrid’ 11beta-hydroxylase/aldosterone synthase gene has greatly facilitated detection. Laboratory assessment (including suppression testing post-operatively, and renin measurement during treatment with aldosterone antagonist medications) can assist in assessing therapeutic responses and in guiding ongoing management. Development of new, highly reliable high-throughput mass spectrometric methods for measuring aldosterone and renin should further enhance detection and reliability of diagnostic workup for PA. PMID:20498828

  8. Laboratory investigation of primary aldosteronism.

    Science.gov (United States)

    Stowasser, Michael; Taylor, Paul J; Pimenta, Eduardo; Ahmed, Ashraf H Al-Asaly; Gordon, Richard D

    2010-05-01

    Availability and wider application of the plasma aldosterone/renin ratio (ARR) as a screening test for primary aldosteronism (PA) has led to the recognition that PA is the most common potentially curable and specifically treatable form of hypertension, possibly accounting for as many as 5-13% of patients. Aldosterone excess also has adverse cardiovascular consequences that go above and beyond hypertension development. These findings support the concept that PA plays an important role in cardiovascular disease states and should be systematically sought and specifically treated, and have led to the development of a US Endocrine Society clinical guideline for the detection, diagnosis and management of this condition. Reliable detection requires that interfering factors (including medications known to alter the ratio) are controlled before ARR measurement (or their effects taken into account), and reliable methods such as fludrocortisone suppression testing are used to confirm PA. Because computed tomography frequently misses aldosterone-producing adenomas yet demonstrates non-functioning nodules, adrenal venous sampling is the only dependable way to differentiate unilateral (surgically correctable) from bilateral (usually treated with aldosterone antagonist medications) forms of PA. For the glucocorticoid-remediable form of PA (familial hyperaldosteronism type I), genetic testing for the causative 'hybrid' 11beta-hydroxylase/aldosterone synthase gene has greatly facilitated detection. Laboratory assessment (including suppression testing post-operatively, and renin measurement during treatment with aldosterone antagonist medications) can assist in assessing therapeutic responses and in guiding ongoing management. Development of new, highly reliable high-throughput mass spectrometric methods for measuring aldosterone and renin should further enhance detection and reliability of diagnostic workup for PA. PMID:20498828

  9. A Discovery Laboratory Investigating Bacterial Gene Regulation

    Science.gov (United States)

    Robert Moss (Wofford College; )

    1999-01-01

    This laboratory exercise introduces students to experimental design and gene regulation using different sugar ("food" sources) and an enzyme assay for beta-glalctosidase to identify different E. coli stains with respect to lac operon mutations, then designing their own experiments to study the various aspects of the lac operon.

  10. 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

  11. 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 smooth bed. The boundary layer process is described over the entire range of the Reynolds number (Re from practically nil to Re = O(107)), from the laminar regime to the transitional regime and to the fully developed turbulent regime. The third section focuses on the effect of the boundary roughness. 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-dominated regime, is covered. Processes such as turbulence reduction/re-laminarization, and increase/decrease in the bed shear stress are presented. The fifth section considers various effects on the wave boundary layer such as the non-uniformity (that due to change in the boundary roughness and that due to change in the flow geometry, i.e., the divergent/convergent environment); irregular waves, the angle of attack of waves; the effect of an externally generated field of turbulence; the suction and injection at the boundary (the ventilated boundary layers); and the vegetation. Also a brief account is given of the steady streaming (in a progressive wave and in a standing wave). The final section summarizes the results of recent research on coherent structures in wave boundary layers.

  12. 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

  13. Experimental investigations of the reaction processes of the system Au+V at a laboratory energy of 447 MeV

    Science.gov (United States)

    Schmieder, Lutz-Michael

    Damped and fusion/fission-like reaction processes of the heavy-ion system 197 Au + 51 V were studied in order to obtain a complete picture of the reaction mechanisms associated with a strong dissipation of the kinetic energy and a small relaxation of the mass asymmetry. Angular, energy, and mass distributions of the projectile-like and the fission fragments were measured. Using a phenomenological analysis of the relation between the reaction angle of the damped phenomena (elastic scattering) and the kinetic energy, the deviation function for the system AU + V was deduced, showing negative values for small angular momentum. Angular-momentum dependent reaction times were determined from this experimental deviation function. The comparison of the fragment charge distributions with data from other reactions shows a qualitative agreement for the damped reaction processes. The experimental data and a dynamic reaction model show a good agreement with the predictions of a transport model based on the exchange of nucleons.

  14. Experimental Investigations on Market Behavior

    OpenAIRE

    Z?akelj, Blaz?

    2012-01-01

    Esta tesis consta de tres ensayos sobre las expectativas de inflación, la incertidumbre de la predicción, y la importancia de la incertidumbre en subastas secuenciales. Todos ellos utilizan un método experimental. El capítulo 1 estudia cómo los individuos predicen la inflación en la economía ficticia y analiza el efecto de las reglas de política monetaria en sus decisiones. Los resultados revelan la heterogeneidad en las reglas de predicción de la inflación y demuestran la importanc...

  15. Experimental Cryosurgery Investigations In Vivo

    OpenAIRE

    Gage, A.A.; Baust, J.M.; Baust, J.G.

    2009-01-01

    Cryosurgery is the use of freezing temperatures to elicit an ablative response in a targeted tissue. This review provides a global overview of experimentation in vivo which has been the basis of advancement of this widely applied therapeutic option. The cellular and tissue-related events that underlie the mechanisms of destruction, including direct cell injury (cryolysis), vascular stasis, apoptosis and necrosis, are described and are related to the optimal methods of technique of freezing to...

  16. Strategic communication: An experimental investigation

    OpenAIRE

    Eckartz, Katharina; Ehses-Friedrich, Christiane

    2014-01-01

    In this paper we attempt to compare theoretically and experimentally three models of strategic information transmission. In particular we focus on the models by Crawford & Sobel (1982), Lai (2010) and Ehses-Friedrich (2011). These three models differ in the information that the receiver possesses and the sender´s knowledge about these information. Lai, 2010 introduce a partially informed decision maker into Crawford & Sobel´s model. Ehses-Friedrich (2011) makes the decision maker´s knowled...

  17. 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...

  18. Experimental Investigation of Microstructured Evaporators

    International Nuclear Information System (INIS)

    Microfluidic devices have become more and more popular over the last decades. Cooling is a topic where microstructures offer significant advantages compared to conventional techniques due the much higher possible surface to volume ratios and short heat transfer lengths. By evaporating of a fluid in microchannels, compact, fast and powerful cooling devices become possible. Experimental results for different designs of microstructured evaporators are presented here. They have been obtained either using water as evaporating coolant or the refrigerant R134a (Tetrafluoroethane). A new microstructured evaporator design consisting of bended microchannels instead of straight channels for a better performance is shown and compared to previous results for the evaporation of R134a in straight microchannels.

  19. Experimental investigation of binary reactions

    International Nuclear Information System (INIS)

    Reviewed are experiments on two-particle processes made on the 70 GeV Serpukhov accelerator with the participation of JINR during 10 years. The main theoretical aspects of the problem of binary reactions are presented in brief. Also giVen are specific features of the method (that of a fine internal target) and spectrometric apparatus using which two-particle reactions have been studied (a magnetic spectrometer with ionization chamber as a target and register, filmless spark spectrometer, an installation with a polarized target, a spectrometer for studying the ?-e-scattering). Experimental data on elastic pp-scatttering are discussed, on the basis of the data a conclusion is made about the growth of the radius of strong-intepaction region with increasing energy. The justice of dispersion ratios at 40-50 GeV energy is proved for elastic ?-p - scattering. Observations of regeneration of neutral K-mesons, Ksub(L)sup(0) ? Ksub(S)sup(0), were made alona with measurements of polarization parameters in elastic scattering of ?+-, p, anti p, K+- on protons, and measurements of electromagnetic formfactor of ?t -pion. Studies of binary processes in the energy range of the Serpukhov accelerator provided a possibility to make a conclusion about the ustice of the main principles of the quantum field theory

  20. 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

  1. Laboratory investigations of impact-generated plasma

    Science.gov (United States)

    Crawford, David A.; Schultz, Peter H.

    1991-01-01

    The characteristics of plasma that was produced in laboratory by hypervelocity impacts were investigated to demonstrate the feasibility of generation of magnetic fields by meteoritic impacts and to explain the presence of paleomagnetic fields on the lunar surface. The impact-generated magnetic fields were found to exhibit spatial and temporal complexity that depended on the impact angle, the velocity, and the projectile/target composition. The results suggest that crater-related paleomagnetism associated with this mechanism should exhibit similar complexity with spatial wavelengths on the order of a fraction of the crater radius.

  2. EXPERIMENTAL INVESTIGATIONS OF COARSE AGGREGATE RECYCLED CONCRETE

    Directory of Open Access Journals (Sweden)

    D.V. Prasada Rao

    2014-11-01

    Full Text Available In India, a huge quantity of construction and demolition wastes is produced every year. These waste materials need a large place to dump and hence the disposal of wastes has become a problem. And the continuous use of natural resources for making conventional concrete leads to the reduction in their availability and results in the increase of the cost of the coarse aggregate and fine aggregate. The possible use of recycling demolition waste as coarse aggregate in the construction industry is thus increasing importance. In addition to the environmental benefits in reducing the demand of land for disposing the waste, the recycling of demolition wastes can also help to conserve the natural resources. When recycled coarse aggregate is used in structural concrete, the assessment of physical, mechanical and durable characteristics of recycled coarse aggregate is very important. The physical and mechanical properties of concrete with the recycled coarse aggregate (RCA are to be evaluated to assess its application as structural concrete. The present work is directed towards the evaluation of concrete using full replacement of natural coarse aggregate (NCA with RCA. The experimental results of mechanical and durability properties are also evaluated and compared with NCA concrete. Recycled coarse aggregate used in the concrete preparation was obtained from the tested laboratory concrete specimens. Tests were carried out to obtain the mechanical properties of RCA such as compressive strength and durability of concrete using rapid chloride permeability test (RCPT. The main problem with RCA concrete is high percentage of water absorption. RCA has high compressive strength comparable to the natural coarse aggregate concrete. This is mainly due to high amount of attached mortar on the surface of the recycled coarse aggregate and highly angular nature of RCA leads to poor quality of coarse aggregate. In RCPT, the chloride penetrating rate is “Moderate” for all grades of concrete with NCA and “High” for all grades of concrete using RCA. Based on the results of the experimental investigation, the RCA can be recommended as structural concrete in limited applications due to its high percentage of water absorption property of RCA.

  3. 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.

  4. 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

  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. 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...

  7. 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)

  8. Experimental investigation of use of horizontal wells in waterflooding

    Energy Technology Data Exchange (ETDEWEB)

    Hadia, N.; Chaudhari, L.; Mitra, Sushanta K. [Department of Mechanical Engineering, IITB-ONGC Joint Research Centre, Indian Institute of Technology Bombay, Mumbai, 400 076 (India); Vinjamur, M. [Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, 400 076 (India); Singh, R. [Institute of Reservoir Studies, ONGC, Ahmedabad (India)

    2007-04-15

    The present experimental study is conducted to investigate the effect of horizontal production well in waterflooding when conventional vertical production well stops oil production. Laboratory experiments have been performed on three-dimensional sand pack models. In the waterflooding experiments, the horizontal production well is turned on after the complete extraction of oil from the vertical production well. The experimental results show that horizontal well increases the ultimate recovery by waterflooding significantly when oil production stops from the conventional vertical production well. Moreover, the position of the horizontal well either at top or bottom of the sand pack has negligible effect on ultimate oil recovery for the sand packs used. (author)

  9. Rhomboid beach pattern: A laboratory investigation

    Science.gov (United States)

    Devauchelle, O.; Malverti, L.; Lajeunesse, É.; Josserand, C.; LagréE, P.-Y.; MéTivier, F.

    2010-06-01

    The formation of beach rhomboid pattern by swash is investigated experimentally. This centimeter-scale structure is classically interpreted as the mark of stationary gravity waves generated by obstacles in supercritical flows. However, thanks to the use of water-based fluids of various viscosity, our experiments show that a rhomboid pattern can develop in subcritical flows. Its angle is primarily a function of the Froude number, as suggested by Woodford (1935), but our data do not support his classical model, nor do they support any of the existing theories. The slowness of the rhombus motion indicates that it is not simply the mark of a hydraulic phenomenon but rather results from the coupling between the water flow and sediment transport.

  10. Experimental investigation of NIRS spatial sensitivity

    Science.gov (United States)

    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 important to understand the relationship between spatial changes in optical properties and corresponding changes in the NIRS signal. We investigated spatial sensitivity of near infrared optical measurements using an experimental approach. It uses a liquid optical phantom as tissue equivalent, which is explored under robot-control by a small, approximately point like perturbation of desired optical properties, and a NIRS instrument for trans-illumination/reflection measurements. The experimentally obtained sensitivity has been analyzed and compared with numerical simulations. In preliminary experiments we investigated the influence of various optical properties of the medium and of source/detector distances on the spatial sensitivity distribution. The acquired sensitivity maps can be used to define characteristic parameters. As an example, we used a 25% threshold to define a penetration depth measure which provides values in good accordance with published ones. To the best of our knowledge this is the first experimental study of NIRS spatial sensitivity. The presented method will allow in depth experimental investigation of the influence of various conditions pertaining to medium such as optical properties of tissue (scattering and absorption) and of the source/detector configuration. PMID:21698012

  11. Fusion of Laboratory and Textual Data for Investigative Bioforensics

    Energy Technology Data Exchange (ETDEWEB)

    Webb-Robertson, Bobbie-Jo M.; Corley, Courtney D.; McCue, Lee Ann; Wahl, Karen L.; Kreuzer, Helen W.

    2013-03-10

    Chemical and biological forensic programs focus on the identification of a threat and acquisition of laboratory measurements to determine how a threat agent may have been produced. However, to generate investigative leads, it might also be useful to identify institutions where the same agent has been produced by the same or a very similar process, since the producer of the agent may have learned methods at a university or similar institution. We have developed a Bayesian network framework that fuses hard and soft data sources to assign probability to production practices. It combines the results of laboratory measurements with an automatic text reader to scan scientific literature and rank institutions that had published papers on the agent of interest in order of the probability that the institution has the capability to generate the sample of interest based on laboratory data. We demonstrate the Bayesian network on an example case from microbial forensics, predicting the methods used to produce Bacillus anthracis spores based on mass spectrometric measurements and identifying institutions that have a history of growing Bacillus spores using the same or highly similar methods. We illustrate that the network model can assign a higher posterior probability than expected by random chance to appropriate institutions when trained using only a small set of manually analyzed documents. This is the first example of an automated methodology to integrate experimental and textual data for the purpose of investigative forensics.

  12. Experimental investigation of fuel-coolant interaction

    International Nuclear Information System (INIS)

    An experimental investigation of thermal interaction of molten metals with cold liquids was made using measurements of transient temperature, pressure, and reactive force; postexperiment microscopic, metallographic, and chemical investigations completed the results. Thermal explosion, film boiling, and inverse Leidenfrost phenomena were considered. The origin of ''jets'' of small particles from the main particle was found to be a triggering mechanism of thermal explosion. Thermal explosion can be a phenomenon of coupled fragmentation and vapor explosion. Fast solidification was recognized as the main process that influenced fragmentation of the hot metal

  13. Reputation or Reciprocity? An Experimental Investigation

    OpenAIRE

    Gaechter, Simon; Falk, Armin

    2001-01-01

    Recent evidence highlights the importance of social norms in many economic relations. However, many of these relationships are long-term and provide repeated game incentives for performance. We experimentally investigate interaction effects of reciprocity and repeated game incentives in two treatments (one-shot and repeated) of a gift-exchange game. In both treatments we observe reciprocity, which is strengthened in the repeated game. A detailed analysis shows that in the repeated game some s...

  14. 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)

  15. 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...

  16. 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...

  17. Experimental investigation subcooled boiling in vertical downflow

    International Nuclear Information System (INIS)

    In ITE-Vinca an experimental program has been conducted to investigate flow boiling in vertical down-flow. For a ratio L/D=125, the pressure drop and wall and fluid temperatures under uniformly heated sub-cooled boiling condition has been obtained for a wide range of operating parameters. The results are presented which show the onset of flow instability and the onset of nucleate boiling. (author)

  18. Vibrations of twisted cantilevered plates - Experimental investigation

    Science.gov (United States)

    Macbain, J. C.; Kielb, R. E.; Leissa, A. W.

    1984-01-01

    The experimental portion of a joint government/industry/university research study on the vibrational characteristics of twisted cantilevered plates is presented. The overall purpose of the research study was to assess the capabilities and limitations of existing analytical methods in predicting the vibratory characteristics of twisted plates. Thirty cantilevered plates were precision machined at the Air Force's Aero Propulsion Laboratory. These plates, having five different degrees of twist, two thicknesses, and three aspect ratios representative of turbine engine blade geometries, were tested for their vibration mode shapes and frequencies. The resulting nondimensional frequencies and selected mode shapes are presented as a function of plate tip twist. The trends of the natural frequencies as a function of the governing geometric parameters are discussed. The effect of support compliance on the plate natural frequency and its impact on numerically modeling twisted plates is also presented.

  19. 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

  20. Experimental investigation of thermosyphon loop thermal performance

    International Nuclear Information System (INIS)

    Highlights: • Experimental investigations are conducted on the thermal performance of the passive loop. • The loop fill charge ratio affected the loop start-up and showed an optimal value between 7% and 10%. • The condenser power effect on the loop thermal performance is studied. • The condenser jacket coolant optimal temperature and flow rate are studied. - Abstract: This paper presents the experimental investigation of a two-phase closed loop. The experimental setup consists of an evaporator and a condenser connected by two insulated tubes. Using water as a working fluid, the experiments were conducted to evaluate the performance of a thermosyphon: the effects of fill charge ratio, the condenser jacket coolant inlet temperature and the mass flow rate. Finally, the results show that the optimal fill charge ratio is between 7% and 10%, the cooling system has the optimal performance when controlling the condenser jacket water temperature and flow rate at 5 °C and at 0.7 l/min respectively. System, loop, evaporator, vapor line, condenser, and liquid line thermal resistances analysis is directed additionally to the pressure and temperature evolutions for the better understand of the main parameters affecting the cooling system performance

  1. Health Evaluation of Experimental Laboratory Mice

    OpenAIRE

    Burkholder, Tanya; Foltz, Charmaine; Karlsson, Eleanor; Linton, C. Garry; Smith, Joanne M.

    2012-01-01

    Good science and good animal care go hand in hand. A sick or distressed animal does not produce the reliable results that a healthy and unstressed animal produces. This unit describes the essentials of assessing mouse health, colony health surveillance, common conditions, and determination of appropriate endpoints. Understanding the health and well-being of the mice used in research enables the investigator to optimize research results and animal care.

  2. 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

  3. 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.

  4. 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

  5. Experimental investigation of tube-shock-absorbers

    International Nuclear Information System (INIS)

    The experimental simulation of the tube form shock-absorbers for dampering the shock experienced by the falling down cask with spent nuclear fuel at Ignalina NPP is carried out. The possibilities of reducing the maximum initial stresses in the shock-absorbers were found out. Dynamic tests of the shock-absorbers' models showed that the maximum initial compression stresses are close to the yield limit of the material. The average overall internal compression stresses depends on the location and position at the fall, and are 1.7-2.5 times lower than the initial maximum compression stress. It was shown that upright cuts and holes in the upper circumference of the tube were to be the effective means to reduce the maximum initial compression stress, and at the same time to improve the effectiveness of the shock-absorbers. Using in the work the cuts and perforations with different geometrical characteristics the maximum initial compression stress was reduced from 1.3 to 2.3 times. The experimental investigations proved the validity and correctness of the methodic of shock-absorbers calculations carried out in the work. (author)

  6. 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

  7. Laboratory Methods For The Investigation of Gas Hydrates

    Science.gov (United States)

    Kulenkampff, J.; Spangenberg, E.

    Sediments in gas hydrate zones are complex composites of solid material and fluids. They may consist of unconsolidated sediments, gas hydrate, water or ice, and gas, depending on hydrostatic pressure and temperature, the sediment type, and genesis. Therefore, petrophysical properties as ultrasonic velocities and electrical resistivity, as well as porosity and permeability may vary within a broad range, and estimates of the gas content and models of gas hydrate deposits are very problematic. Evaluation methods for logging and geophysical field data in gas hydrate deposits are not yet available. This is due to the lack of laboratory measurements of physical pa- rameters in relation to the gas content and the sediment type. Standard interpretation methods have been applied with questionable success. Thus a transportable laboratory system (FLECAS: field laboratory experimental core analysis system) has been developed at the GFZ for the investigation of hydrate bear- ing cores. It consists of a thermostatted vessel (-10C to 60C) with pressure control (max. 70 MPa) and measurement setups for pore volume, sample volume, permeabil- ity, electrical resistivity, ultrasonic compressional and shear wave velocity. Measurements were done on synthetic gas hydrate bearing sands: During the temper- ature increase at first the frozen water melts, resulting in a decrease of resistivity and velocity. A further decrease in pressure causes the hydrate to dissociate, which tem- porarily decreases the temperature, and then again resistivity and velocity decrease, because water is released. At last the material looses its mechanical strength. Presently the system is used for core analysis of naturally occurring gas hydrates in the permafrost region at the Mallik gas hydrate production test well in Canada.

  8. Failure investigations in the nuclear materials laboratory

    International Nuclear Information System (INIS)

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

  9. Experimental investigation of wingtip aerodynamic loading

    Science.gov (United States)

    Van Aken, Johannes M.

    1990-01-01

    An experimental investigation was performed to obtain the aerodynamic loading of a series of wingtips. The wingtips varied in taper ratio (1.0, 0.6, and 0.3) and in sweep angle (0, 20, 30, 35, and 45 deg). The wingtips were tested separately (wingtip only configuration) and while mounted on a semi-span wing. The quarter-chord sweep angle of the wing was varied from 30 deg forward sweep, to unswept, to 30 deg. aft sweep. Wingtip loading was obtained from a six component strainguage balance mounted in the wingtip. The effect of wing sweep and wingtip taper and wingtip sweep on the wingtip lift curve slope, drag polar, and pitching moment behavior is discussed. The obtained wingtip data was used to define blade tip platforms, suitable for use in the Free-Tip Rotor configuration. The Free-Tip Rotor has blade tips, which are allowed to weathervane into the blade tip's relative wind. A passive control moment is applied to the blade tip's pitch axis so as to cause blade tip motion around a prescribed null point providing a finite blade tip lift.

  10. EXPERIMENTAL MODEL TO INVESTIGATE DRUGS FOR EPILEPSY

    Directory of Open Access Journals (Sweden)

    Jesús Carlos Ruvalcaba Ledezma

    2013-09-01

    Full Text Available Introduction.Epilepsy is one of the most common neurological disorders characterized by seizures. Epileptic seizures result from excessive, abnormal, or hyper synchronous neuronal activity in the brain. It is a public health problem that is not yet curable but which can be controlled. A high percentage of patients who suffer from epilepsy do not have seizures control even when using the existing treatments. Therefore, an experimental study was conducted with the objective of determining the effect of the Bufo-toxin in rats belonging to the BALB/c and the Wistar strainsin order to diagnose the group of symptoms that confer lethality to this toxin and which can work as a treatment to such disease.Methodology the bufo-toxin was obtained from toads, then it was placedin alcoholic solution and it was applied to the rats in doses of 5 by 5 for up to 20 Units with an insulin syringe though the intramuscular via. Observations were registered and when the rats died a post-mortem examination was conducted in order to describe the effect of the toxin in the internal organs. Results. The rats that were inoculated within 20 units of the toxin showed epileptic seizures and finally cerebral spill or heart attack. Discussion and conclusion. This model can be used to investigate on useful drugs against epilepsy and even heart diseases, such as, hypertension andheart attacks.

  11. 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, a

  12. Laboratory Investigations into Micromechanical Mechanisms Controlling Earthquake Nucleation

    Science.gov (United States)

    Selvadurai, P. A.; Glaser, S. D.; Kiwan, R. H.

    2013-12-01

    Improving our understanding of factors controlling spontaneous shear rupture nucleation on a frictional fault would help better define the important physical processes contributing to earthquake rupture and faulting. Our current laboratory investigations quantify the local stress states on a laboratory fault, which control the transition of sliding from stable (quasi-static) to unstable (dynamic), commonly referred to as earthquake nucleation. A fault is experimentally modeled using two Poly(methyl methacrylate) samples in a direct shear configuration. During nucleation, we observed sudden, elastodynamic stress changes using an array of 16 acoustic emission (AE) sensors. Measurements of absolute displacement from these sensors allowed us to characterize general source mechanics using moment tensor inversion. This technique is widely used in seismology and we observe double-couple (DC) focal mechanisms; a source commonly used to characterize in situ earthquakes. During nucleation, we sometimes observe swarms of smaller, ';foreshock' earthquakes (Mw ~ -7), localized in time and space, prior to the incipient mainshock (Mw ~ -3.25). In general, the local perturbations in the stress field induced by the stress drop (??) from a single foreshock was insufficient to cause the subsequent foreshock at the spatial distances recorded experimentally. This implied that the underlying process driving the foreshock sequence (and eventual mainshock) was aseismic slip over the nucleation zone recorded using non-contact sensors. Spatio-temporal distributions of the foreshocks and the near-fault aseismic motions were shown to be directly related to: i) the rate at which the average bulk stress accumulates across the fault (d?f /dt) and ii) the heterogeneity of normal stress caused by the irregular distribution of asperities, respectively. (A) Locations of the foreshocks (FS1-FS9) determined using p-wave travel times from multiple AE sensors. The locations were superimposed on interfacial pressure measurements obtained using pressure sensitive film (high normal stresses appear as red). (B) Enhanced view of the location of FS6 on the pressure sensitive film. (C) Results of moment tensor inversion (red) fitting the experimental data (black) measured by five AE sensors (PZ7-PZ12) for FS6. The double-couple source was representative of a Mw = -7.0 earthquake.

  13. 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.)

  14. 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-

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

    International Nuclear Information System (INIS)

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

  16. 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…

  17. Experimental investigation on breaching of embankments:

    OpenAIRE

    Zhu, Y.; Visser, P. J.; Vrijling, J. K.; Wang, G. Q.

    2011-01-01

    Breaching of embankments has recently drawn more and more attention due to its importance in the development of early warning systems for embankment failures, in the evacuation plans of people at risk, in the design method of embankments based on a risk-approach, etc. The erosion process observed during embankment breaching tests in the laboratory and the analysis of the results are described in this paper. Five embankments, one constructed with pure sand, four with different sand-silt-clay m...

  18. An Open-Ended Investigative Microbial Ecology Laboratory for Introductory Biology

    Science.gov (United States)

    Jones-Held, Susan; Paoletti, Robert; Glick, David; Held, Michael E.

    2010-01-01

    In this article we describe a multi-week investigative laboratory in microbial ecology/diversity and nitrogen cycling that we have used in our introductory biology course. This module encourages active student involvement in experimental design, using the scientific literature and quantitative analysis of large data sets. Students analyze soil…

  19. 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…

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

    OpenAIRE

    J.B Agboola; O.K Abubakre

    2009-01-01

    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 w...

  1. Structural failures and experimental investigations of lightweightstructures.

    Czech Academy of Sciences Publication Activity Database

    Drdácký, Miloš

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

  2. Experimental investigation of 4-dimensional superspace crystals

    Energy Technology Data Exchange (ETDEWEB)

    Rasing, T.; Janner, A.

    1983-09-01

    The symmetry of incommensurate crystals can be described by higher dimensional space groups in the so called superspace approach. The basic ideas are explained and used for showing that superspace groups provide an adequate frame for analyzing experimental results on incommensurate crystals.

  3. 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–? turbulencous 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.

  4. 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.

  5. 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.

  6. Experimental investigation of planar ion traps

    OpenAIRE

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

    2005-01-01

    Chiaverini et al. [Quant. Inf. Comput. 5, 419 (2005)] recently suggested a linear Paul trap geometry for ion trap quantum computation that places all of the electrodes in a plane. Such planar ion traps are compatible with modern semiconductor fabrication techniques and can be scaled to make compact, many zone traps. In this paper we present an experimental realization of planar ion traps using electrodes on a printed circuit board to trap linear chains of tens of 0.44 micron...

  7. Experimental investigation of consumer price evaluations

    OpenAIRE

    Sándor, Z.; Franses, Ph.H.B.F.

    2004-01-01

    We develop a procedure to collect experimental choice data for estimating consumer preferences with a special focus on consumer price evaluations. For this purpose we employ a heteroskedastic mixed logit model that measures the effect of the way prices are specified on the variance of choice. Our procedure is based on optimal design ideas from the statistics literature and on some algorithms for constructing choice designs published in marketing journals. In an empirical application on mobile...

  8. 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

  9. 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

  10. The experimental investigation of supersymmetry breaking

    International Nuclear Information System (INIS)

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

  11. Experimental investigation of 6Be cluster decay

    International Nuclear Information System (INIS)

    A complete kinematics measurement was performed using the 6Li(3He,t) charge exchange reaction to populate 6Be at Elab = 50 MeV. Decay mode of the ground and first excited states were studied through the analysis of the energy and angular distributions of the break-up particles in the 6Be center of mass frame. Two-body decay is observed above the first excited state but not firmly assigned to a 6Be resonant state. Experimental challenges regarding the identification of true 6Be events in the excitation energy region 5 x < 20 MeV are discussed. (author)

  12. 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

  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.

  14. An experimental investigation of wind turbine wakes

    OpenAIRE

    Blomhoff, Hedda Paulsen

    2012-01-01

    In the present study the wake behind a scaled; Horizontal Axis Wind Turbine (HAWT) has been investigated. The experiments were performed at the Department of Energy and Process Engineering, at the Norwegian University of Science and Technology, NTNU. The turbine was installed in the wind tunnel at the department and measurements were performed at several distances behind the turbine to examine the development of the flow. A five-hole pitot probe was applied as measurement instrument. The inst...

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

    Energy Technology Data Exchange (ETDEWEB)

    Nix, Andrew Carl

    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. • 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.

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

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas BØdker Technical University of Denmark,

    The role of ions in producing aerosols in Earth’s atmosphere is an area of very active research. Atmospheric and experimental 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 and Ternary Nucleation. 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. Recent experimental work 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 link between cosmic rays and Earth's climate and there is thus a need to corroborate the results in a different experiment. The present results are obtained in the same laboratory, but using a new 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.

  17. 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.

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

    OpenAIRE

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

    2000-01-01

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

  19. 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.

  20. 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 ...

  1. Experimental investigation of planar ion traps

    CERN Document Server

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

    2005-01-01

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

  2. Experimental investigation of planar ion traps

    International Nuclear Information System (INIS)

    Chiaverini et al. [Quantum Inf. Comput. 5, 419 (2005)] recently suggested a linear Paul trap geometry for ion-trap quantum computation that places all of the electrodes in a plane. Such planar ion traps are compatible with modern semiconductor fabrication techniques and can be scaled to make compact, many-zone traps. In this paper we present an experimental realization of planar ion traps using electrodes on a printed circuit board to trap linear chains of tens of charged particles of 0.44 ?m diameter in a vacuum of 15 Pa (10-1 torr). With these traps we address concerns about the low trap depth of planar ion traps and develop control electrode layouts for moving ions between trap zones without facing some of the technical difficulties involved in an atomic ion-trap experiment. Specifically, we use a trap with 36 zones (77 electrodes) arranged in a cross to demonstrate loading from a traditional four-rod linear Paul trap, linear ion movement, splitting and joining of ion chains, and movement of ions through intersections. We further propose an additional dc-biased electrode above the trap which increases the trap depth dramatically, and a planar ion-trap geometry that generates a two-dimensional lattice of point Paul traps

  3. Experimental investigation on fracture of layered plates

    Science.gov (United States)

    Agnihotri, Servesh; Parameswaran, Venkitanarayanan

    2015-03-01

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

  4. Experimental investigation of coupled natural circulation loops

    International Nuclear Information System (INIS)

    The removal of decay heat from the main coolant loop of pressurized water, boiling water, and liquid-metal nuclear reactors has been of concern for many years. In addition, safety systems must continue to remove heat from components like steam generators or pressurizers long after the reactor is shut down. One type of heat removal is that occurring by natural convection in piping loops when pumps are not operating. In this paper, transient experiments were performed using two natural convection loops in series. The fluid in both loops was water at a pressure of 1 to 10 atm. Measurements were made of the temperature at key points in both loops over the duration of the tests, which were 4 to 6 h long. By using the assumption that after several hours the loops were operating in a quasi-steady-state condition, estimates could be made concerning the fluid circulation rates and heat transfer rates in various parts of the system. The flow rates were very low and in the laminar flow range. There was essentially no time lag before the start of flow in the second loop. The heat exchanger coupling the two loops was of a design whose performance could not be easily predicted. The measurement of key loop temperature as a function of time provides a simple means of obtaining preliminary predictions in planning extensive experimental test programs for complicated thermal systems

  5. 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.

  6. Over-confidence and low-cost heuristics: An experimental investigation of choice behavior

    OpenAIRE

    Cicognani, Simona; MITTONE, LUIGI

    2014-01-01

    This paper extends choice theory by allowing for the interaction between cognitive costs and imitative dynamics. The authors experimentally investigate the role of imitation when participants face a task which is costly in cognitive terms. In order to disentangle different choice dynamics, they devise a laboratory experiment with a novel experimental task in which they model the choice of different alternatives through high or low cognitive costs and feedback information provided to subjects....

  7. 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)

  8. 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.

  9. Experimental and analytical investigation of a fluidic power generator

    Science.gov (United States)

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

    1981-01-01

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

  10. Simulation and Experimentation in an Astronomy Laboratory, Part II

    Science.gov (United States)

    Maloney, F. P.; Maurone, P. A.; Hones, M.

    1995-12-01

    The availability of low-cost, high-performance computing hardware and software has transformed the manner by which astronomical concepts can be re-discovered and explored in a laboratory that accompanies an astronomy course for non-scientist students. We report on a strategy for allowing each student to understand fundamental scientific principles by interactively confronting astronomical and physical phenomena, through direct observation and by computer simulation. Direct observation of physical phenomena, such as Hooke's Law, begins by using a computer and hardware interface as a data-collection and presentation tool. In this way, the student is encouraged to explore the physical conditions of the experiment and re-discover the fundamentals involved. The hardware frees the student from the tedium of manual data collection and presentation, and permits experimental design which utilizes data that would otherwise be too fleeting, too imprecise, or too voluminous. Computer simulation of astronomical phenomena allows the student to travel in time and space, freed from the vagaries of weather, to re-discover such phenomena as the daily and yearly cycles, the reason for the seasons, the saros, and Kepler's Laws. By integrating the knowledge gained by experimentation and simulation, the student can understand both the scientific concepts and the methods by which they are discovered and explored. Further, students are encouraged to place these discoveries in an historical context, by discovering, for example, the night sky as seen by the survivors of the sinking Titanic, or Halley's comet as depicted on the Bayeux tapestry. We report on the continuing development of these laboratory experiments. Futher details and the text for the experiments are available at the following site: http://astro4.ast.vill.edu/ This work is supported by a grant from The Pew Charitable Trusts.

  11. Flood Water Crossing: Laboratory Model Investigations for Water Velocity Reductions

    Directory of Open Access Journals (Sweden)

    Kasnon N.

    2014-01-01

    Full Text Available The occurrence of floods may give a negative impact towards road traffic in terms of difficulties in mobilizing traffic as well as causing damage to the vehicles, which later cause them to be stuck in the traffic and trigger traffic problems. The high velocity of water flows occur when there is no existence of objects capable of diffusing the water velocity on the road surface. The shape, orientation and size of the object to be placed beside the road as a diffuser are important for the effective flow attenuation of water. In order to investigate the water flow, a laboratory experiment was set up and models were constructed to study the flow velocity reduction. The velocity of water before and after passing through the diffuser objects was investigated. This paper focuses on laboratory experiments to determine the flow velocity of the water using sensors before and after passing through two best diffuser objects chosen from a previous flow pattern experiment.

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

    OpenAIRE

    Labiod-aloui, Zehour; Trouzine, Habib; Ghembaza, Moulay Smai?ne; 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...

  13. Experimental and Modeling Investigation of Shallow Water Table Fluctuations in Relation to Reverse Wieringermeer Effect

    OpenAIRE

    Ibrahimi Mohamed Khaled; Miyazaki Tsuyoshi; Nishikawa Kohei; Nishimura Taku; Imoto Hiromi

    2011-01-01

    Soil column experiments and modeling investigations were performed to study the behavior of shallow water table in response to various recharge events. Hence, shallow water table fluctuations inside sandy (Toyoura sand) and clayey (Chiba light clay) soil columns in response to surface and sub-surface recharge events were investigated under laboratory conditions. Experimental results showed that small application of water could raise the shallow water table level more than 100 times in depth i...

  14. Experimental Investigation of the Wind Turbine Blade Root Flow:

    OpenAIRE

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

    2010-01-01

    Several methods from experimental to analytical are used to investigate the aerodynamics of a horizontal axis wind turbine. To understand 3D and rotational effects at the root region of a wind turbine blade, correct modeling of the flow field is essential. Aerodynamic models need to be validated by accurate experimental data. In this paper, the experimental results of the aerodynamic behavior of a model wind turbine blade, by focusing on the blade root flow, are presented. The measurements ar...

  15. 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)

  16. 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.)

  17. CIEMAT's Experimental Activity in the Investigation of Severe Accidents

    International Nuclear Information System (INIS)

    The CIEMAT has three medium and small scale experimental plants in the service of research into specific phenomena associated with severe accidents in nuclear power plants. Experimental investigation is supplemented with analytical type work for validating, improving and developing models which accurately estimate the phenomenology expected under severe accident conditions. (Author)

  18. 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 ...

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

    OpenAIRE

    Ruspini, Leonardo Carlos

    2013-01-01

    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...

  20. 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 deformatiling perspective, the modulus of deformation shows the most sensitivity to field conditions because of the presence of joints found in the field. 14 refs., 1 tab

  1. 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

  2. Experimental program for investigation of high power density MHD

    Science.gov (United States)

    Lineberry, J. T.; Schmidt, H. J.; Chapman, J. N.

    Research on magnetohydrodynamic (MHD) power generation, directed at the proof-of-concept of combustion MHD as a viable source for use with space-based weapons systems, is described. Currently, small-scale laboratory evaluations of a solid-aluminum, carbon-fueled hybrid combustor are being completed. Ultimate plans for this research include coupling of this combustor to an MHD generator to demonstrate high power density in the laboratory. This report includes experimental results from the initial hybrid combustor tests. The design of this combustor system and its design point are detailed. Experimental data from firings are presented and analyzed. The burn or regression rate for this fuel is summarized. The combustor tests have been successful; the design point for this system was readily achieved and sustained.

  3. 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.

  4. Diagnostic Protocol Used in Central Disease Investigation Laboratory Dhaka, Bangladesh

    Directory of Open Access Journals (Sweden)

    M. H. Rashid

    2003-01-01

    Full Text Available The present study was carried out during a period of four months at Central Disease Investigation Laboratory, Dhaka with the primary aim to measure the frequency of Gumboro in poultry based on sample submission and diagnostic protocol they have been using for poultry disease surveillance. The birds >30 days had a more frequency of Gumboro and the mortality was also comparatively higher in these group (15.66 risk ratio and 4.65 rate ratio. BV 300 strain was affected at a relatively higher rate and among the production group layer was evidenced to be more susceptible than broiler to IBD infection.

  5. Diagnostic Protocol Used in Central Disease Investigation Laboratory Dhaka, Bangladesh

    OpenAIRE

    M.H. Rashid; M. Atikuzzaman; Rahman, M.A.; Hoque, M. A.; M.Y.E. Chowdhury

    2003-01-01

    The present study was carried out during a period of four months at Central Disease Investigation Laboratory, Dhaka with the primary aim to measure the frequency of Gumboro in poultry based on sample submission and diagnostic protocol they have been using for poultry disease surveillance. The birds >30 days had a more frequency of Gumboro and the mortality was also comparatively higher in these group (15.66 risk ratio and 4.65 rate ratio). BV 300 strain was affected at a relatively higher rat...

  6. a Laboratory Investigation of Two-Celled Vortex Flows

    Science.gov (United States)

    Pauley, Randal Lee

    An experimental study of the steady-state kinematics, dynamics, and morphology of two-celled vortex flows has been conducted in the Ward-type tornado vortex chamber (TVC) at Purdue University, with emphasis on exploring the vertical momentum balance in the vortex core and better defining the flow near the external boundaries of the TVC. The TVC was modified for these experiments to more closely compare with numerical models and to allow the implementation of new measurement techniques. Observations of the visualized flow in two-celled vortices and time -averaged static pressure measurements on the axis and at the boundaries of the TVC are reported. Laboratory observations and measurements are compared with results of a numerical model of the TVC flow authored by Rotunno (1984). Laboratory and numerical results are analyzed in terms of the vertical momentum equation. Results show that in the Purdue TVC the flow downstream of the vortex breakdown is everywhere two-celled, with the strongest axial downflow occurring at middle levels. The pressure on the axis in the two-celled vortices increases with height immediately downstream of the breakdown, with the axial pressure gradient tending toward zero farther downstream. The flow-straightening baffle at the downstream terminus of the vortex in the TVC does not critically affect the flow provided the vortex breakdown is well upstream. Analysis of the laboratory findings within the context of the vertical momentum equation shows that the vertical shear stress can play an important role in the axial momentum balance of two-celled vortices by opposing the filling of the vortex core from aloft and so helping to maintain low pressure and high velocities near the surface. The numerical model of Rotunno (1984) is successful in qualitatively replicating several of the flow characteristics in the TVC, including two-celled flow, multiple subsidiary vortices, strongest downflow at middle levels, axial pressure increasing with height, and the role of the vertical shear stress in the axial momentum balance.

  7. 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.

  8. 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).

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

    OpenAIRE

    Rahman, M. M.; Khan, M. A. R.; Kadirgama, K.; Noor, M. M.; Bakar, R. A.

    2011-01-01

    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...

  10. Experimental investigation of radiation transmission through a water spray

    OpenAIRE

    Parent, Gilles; Boulet, Pascal; Gauthier, Se?gole?ne; Blaise, Je?ro?me; Collin, Anthony

    2006-01-01

    Radiation attenuation by a water spray is experimentally investigated. Spectral transmissivity measurements are performed between 1000 and 7000 cm-1 with an experimental device involving a Fourier transform spectrometer. The spray is produced by a so-called Tee-Jet 400067 nozzle for water pressure between 1.5 and 6 bars. Key features like mean attenuation levels due to absorption and scattering by droplets and complex absorption pattern by water vapor are identified. Known effect of attenuati...

  11. Combined Numerical and Experimental Investigation of Progressive Failure of Composites

    OpenAIRE

    Deuschle, H. Matthias; Wittel, Falk K.; Gerhard, Henry; Busse, Gerhard; Kroeplin, Bernd-H.

    2004-01-01

    The combination of Finite Element Method (FEM) simulation and experimental photo-elasticity provides both qualitative and quantitative information about the stress field in a polymer composite and particularly along the fibre-matrix boundary. Investigations were made using model specimens containing up to five parallel glass fibres loaded at angles from 0 to 15 degrees. The material properties of the geometrically equivalent FE models are calibrated using the experimental ph...

  12. Experimental investigations of thermal interaction between corium and coolants

    Science.gov (United States)

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

    2008-03-01

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

  13. Possible experimental investigation of the phenomenon of anomalous ionization

    International Nuclear Information System (INIS)

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

  14. Experimental transmission of the nematode Echinomermella matsi to the sea urchin Strongylocentrotus droebachiensis in the laboratory.

    Science.gov (United States)

    Stien, A; Halvorsen, O

    1998-06-01

    Three experiments were conducted to investigate the possibility of maintaining the Echinomermella matsi-Strongylocentrotus droebachiensis system in the laboratory. The experiments were performed by injecting E. matsi larvae taken directly from gravid female nematodes into the mouths of sea urchins. In all experiments, this treatment resulted in a higher infection in treated animals than in unmanipulated controls. The successful establishment of larvae indicates that E. matsi has a monoxenous life cycle. The growth of larvae in experimentally infected hosts was slow, indicating that the generation time of the parasite is of the same magnitude as the life expectancy of the host, 1-2 yr. This slow growth rate suggests that considerable resources will be needed to maintain the system in the laboratory. PMID:9645884

  15. 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.

  16. 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)

  17. 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.

  18. Experimental and numerical investigation of one-dimensional waterflood in porous reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Hadia, N.; Chaudhari, L.; Mitra, Sushanta K. [IITB-ONGC Joint Research Centre, and Department of Mechanical Engineering, Indian Institute of Technology Bombay, Mumbai 400 076 (India); Aggarwal, A.; Vinjamur, M. [IITB-ONGC Joint Research Centre, and Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai 400 076 (India); Singh, R. [IITB-ONGC Joint Research Centre, and Institute of Reservoir Studies, ONGC, Ahmedabad (India)

    2007-11-15

    Experimental and numerical investigation of relative permeability and oil recovery from the porous reservoir are described for short and long core samples. The relative permeability ratios, which are function of water saturation, obtained from laboratory core flooding experiments have been used for prediction of oil recovery through numerical simulation of non-dimensional Buckley-Leverett equation. The simulation results for oil recovery compared well with recovery results obtained from core flooding experiments. (author)

  19. 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.

  20. 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.

  1. COMPUTERIZED LABORATORY NOTEBOOK CONCEPT FOR GENETIC TOXICOLOGY EXPERIMENTATION AND TESTING

    Science.gov (United States)

    We describe a microcomputer system utilizing the Computerized Laboratory Notebook (CLN) concept developed in our laboratory for the purpose of automating the Battery of Leukocyte Tests (BLT). The BLT was designed to evaluate blood specimens for toxic, immunotoxic, and genotoxic e...

  2. Numerical and experimental investigation of bump foil mechanical behaviour

    DEFF Research Database (Denmark)

    Larsen, Jon Steffen; Cerda Varela, Alejandro Javier

    2014-01-01

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

  3. 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)

  4. Experimental investigation of electron channeling radiation in diamond crystal

    International Nuclear Information System (INIS)

    New results on the experimental investigation of the electron in a diamond crystal, obtained at the Tomsk synchrotron, are presented. The experimental data are systematized in such a way that it allows observation of a transition from axial to planar channeling and the variation of a maximum position in the radiation spectrum at planar channeling with the electron energy change. A comparison of the spectra of the coherent bremsstrahlung radiation and radiation at planar and axial channeling is performed, and the radiation losses in angular cone 1/? are obtained. (author)

  5. 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)

  6. 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

  7. Combined Numerical and Experimental Investigation of Progressive Failure of Composites

    CERN Document Server

    Deuschle, H M; Gerhard, H; Busse, G; Kröplin, B H

    2004-01-01

    The combination of Finite Element Method (FEM) simulation and experimental photo-elasticity provides both qualitative and quantitative information about the stress field in a polymer composite and particularly along the fibre-matrix boundary. Investigations were made using model specimens containing up to five parallel glass fibres loaded at angles from 0 to 15 degrees. The material properties of the geometrically equivalent FE models are calibrated using the experimental photoelastic outputs. In contrast to the experimental results, FE simulations provide full 3D stress fields. For verification purposes, the 3D stress fields are reduced to two-dimensional synthetic photoelastic phase images, showing good agreement. Furthermore, detailed studies on the components of the stress tensor, particularly statements concerning the shear transmitted by fibre-matrix boundary, progressive fibre failure and the effect of load angle variation are presented.

  8. 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.)

  9. 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

  10. 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

  11. 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

  12. Experimental Investigation of Acoustically Enhanced Dewaterability of Unconsolidated Soils

    Science.gov (United States)

    Kim, Young-Uk; Hoang, Tien Trung; Chun, Young Woo; Ming, Zhang Guang

    2012-07-01

    The acceleration of water content reduction by vibrational energy was investigated with a series of laboratory tests. Vibration was generated with a poly(vinylidene fluoride) (PVDF) film as a flexible transducer at various frequencies. Test conditions included the power and duration of sonic energy, and the soil type. Test results showed a significant increase in dewaterability when ultrasound was applied. The time required for the outflow of the same amount of water was shorter for the sonicated conditions. The degree of enhancement varied with the test conditions. Using the test results, we discuss the potential development of a new method that can reduce the dewatering period.

  13. Experimental Investigation on Selective Laser Melting of Glass

    Science.gov (United States)

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

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

  14. Theoretical and experimental investigations of electron attachment to biomolecules

    International Nuclear Information System (INIS)

    In our age, humans are increasingly often exposed to radiation which can damage important biomolecules. Such defects are generated also via slow secondary electrons. In the present thesis basic effects of electron attachment to glycine, valine and proline in gasphase are investigated. Both experimental and theoretical methods are combined to reveal the nature of the underlying processes in gas phase and microsolvation. Also results of electron attachment to musk ketone and 2,4-dinitrotoluene are presented. (author)

  15. 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...

  16. 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.

  17. 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...

  18. Experimental investigations of the viscosity of nanofluids at low temperatures

    OpenAIRE

    Aladag, Bahadir; Salma, Halelfadl; Doner, Nimeti; Maré, Thierry; Steven, Duret; Estellé, Patrice

    2012-01-01

    The effects due to temperature and shearing time on viscosity for Al2O3/water and CNT/water based nanofluids at low concentration and low temperatures are experimentally investigated. The viscosity data were collected using a stress-controlled rheometer equipped with parallel plate geometry under up and down shear stress ramp. CNT and Al2O3 water based nanofluids exhibited hysteresis behaviour when the stress is gradually loaded and unloaded, depending also on shearing time. Experiments also ...

  19. 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 ...

  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. ATTEMPS TO ESTABLISH EXPERIMENTAL CYCLOSPORA CAYETANENSIS INFECTION IN LABORATORY ANIMALS

    Science.gov (United States)

    Attemps were made to develop an animal model for Cyclospora cayetanensis to identify a practical laboratory host for studing human cyclosporiasis. Oocysts collected from stool of infected humans in the United States, Haiti, Guatemala, Peru, and Nepal were held in potassium dichro...

  2. ATTEMPTS TO ESTABLISH EXPERIMENTAL CYCLOSPORA CAYETANENSIS INFECTION IN LABORATORY ANIMALS

    Science.gov (United States)

    Attempts were made to develop an animal model for Cyclospora cayetanensis to identify a practical laboratory host for studying human cyclosporiasis. Oocysts collected from stool of infected humans in the United States, Haiti, Guatemala, Peru and Nepal were held in potassium dich...

  3. 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...

  4. Experimental-theoretical investigation of the thermal explosion

    International Nuclear Information System (INIS)

    It is suggested that thermal explosions are caused by the latent heat of fusion liberated when the heat transfer at the surface of the molten metal mass is sufficiently intensive to subcool the metal below the solidification point. From a couple of experiments performed by the authors on different metals brought into contact in the molten state with cold water as well as from experiments of the same kind in other laboratories it can be concluded that thermal explosions appear only under special, precisely determined conditions. The experimental techniques applied in this work comprise measurement of the temperature history during the thermal interaction of the hot and the cold liquid and simultaneously observe and record the phenomena by fast photography

  5. 21 CFR 312.160 - Drugs for investigational use in laboratory research animals or in vitro tests.

    Science.gov (United States)

    2010-04-01

    ...for investigational use in laboratory research animals or in vitro tests. 312...Investigational Use in Laboratory Research Animals or In Vitro Tests § 312...investigational use in laboratory research animals or in vitro tests....

  6. 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.

  7. 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.

  8. 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

  9. 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.

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

    OpenAIRE

    Hall, Adam C.; Harrington, Mary E.

    2003-01-01

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

  11. Experimental investigation of scroll based organic Rankine cycles

    Energy Technology Data Exchange (ETDEWEB)

    Tarique, Md Ali; Dincer, I.; Zamfirescu, C. [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology (Canada)], E-mail: Md.Ali.Tarique@uoit.ca, email: Ibrahim.Dincer@uoit.ca, email: Calin.Zamfirescu@uoit.ca

    2011-07-01

    Global awareness of the greenhouse effect and global warming due to carbon- based fuel combustion has spurred interest in the use of low-grade heat that is abundantly available from renewable energy sources and also from the waste heat produced at plants. This paper investigates the performance of a scroll expander in an Organic Rankine Cycle (ORC), experimentally and analytically, with the purpose of using low-grade sustainable energy sources in mind. The expander was modeled on the basis of thermodynamic and fluid flow characteristics within a control volume boundary and the isentropic efficiency of the expander, which is an important factor in optimizing its performance, was determined. From the experimental analysis, the maximum isentropic efficiency was found to be 66% at 120C source temperature. This shows that mechanical work or electricity can be generated using a scroll expander in a low power ORC. Moreover, the analytical model is validated with regard to the optimal expansion.

  12. Experimental investigation of radiation transmission through a water spray

    International Nuclear Information System (INIS)

    Radiation attenuation by a water spray is experimentally investigated. Spectral transmissivity measurements are performed between 1000 and 7000cm-1 with an experimental device involving a Fourier transform spectrometer. The spray is produced by a so-called Tee-Jet 400067 nozzle for water pressure between 1.5 and 6bar. Key features like mean attenuation levels due to absorption and scattering by droplets and complex absorption pattern by water vapor are identified. Known effect of attenuation modification when increasing the water pressure is observed. A simulation is also performed to evaluate a numerical code developed in a companion study. The achieved agreement demonstrates the ability of the simulation to describe the radiation attenuation by the spray

  13. Experimental investigation of radiation transmission through a water spray

    Science.gov (United States)

    Parent, G.; Boulet, P.; Gauthier, S.; Blaise, J.; Collin, A.

    2006-01-01

    Radiation attenuation by a water spray is experimentally investigated. Spectral transmissivity measurements are performed between 1000 and 7000cm with an experimental device involving a Fourier transform spectrometer. The spray is produced by a so-called Tee-Jet 400 067 nozzle for water pressure between 1.5 and 6 bar. Key features like mean attenuation levels due to absorption and scattering by droplets and complex absorption pattern by water vapor are identified. Known effect of attenuation modification when increasing the water pressure is observed. A simulation is also performed to evaluate a numerical code developed in a companion study. The achieved agreement demonstrates the ability of the simulation to describe the radiation attenuation by the spray.

  14. 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...

  15. Analytical and experimental investigation of mistuning in propfan flutter

    Science.gov (United States)

    Kaza, Krishna Rao V.; Mehmed, Oral; Williams, Marc; Moss, Larry A.

    1987-01-01

    An analytical and experimental investigation of the effects of mistuning on propfan subsonic flutter was performed. The analytical model is based on the normal modes of a rotating composite blade and a three-dimensional subsonic unsteady lifting surface aerodynamic theory. Theoretical and experimental results are compared for selected cases at different blade pitch angles, rotational speeds, and free-stream Mach numbers. The comparison shows a reasonably good agreement between theory and experiment. Both theory and experiment showed that combined mode shape, frequency, and aerodynamic mistuning can have a beneficial or adverse effect on blade damping depending on Mach number. Additional parametric results showed that alternative blade frequency mistuning does not have enough potential for it to be used as a passive flutter control in propfans similar to the one studied. It can be inferred from the results that a laminated composite propfan blade can be tailored to optimize its flutter speed by selecting the proper ply angles.

  16. 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…

  17. 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. a practical system.

  18. Experimental investigation of panel radiator heat output enhancement for efficient thermal use under actual operating conditions

    Science.gov (United States)

    Calisir, Tamer; Baskaya, Senol; Onur Yazar, Hakan; Yucedag, Sinan

    2015-05-01

    In this study the heat output of a panel-convector-convector-panel radiator (PCCP) under controlled laboratory conditions under Turkish household and especially Ankara conditions was investigated experimentally. In this sense, investigations were performed for different heating water mass flow rates, water inlet temperatures and radiator inlet and outlet connection positions, which are most commonly used in Turkey. An experimental setup was built for this purpose in a test room where temperature was controlled and held constant during the experiments. Inlet and outlet water temperatures and mass flow rates were measured and heat output of the radiator was calculated. Infrared thermal camera visualizations of the steel panel radiator front surface were also performed.

  19. Experimental base for investigations for the validity of atomic energy safety

    International Nuclear Information System (INIS)

    The experimental base of the Scientific and Industrial Association LUCH, included in the National Nuclear Centre of the Republic of Kazakstan, contains three research reactors: IGR, IVG.1M, RA; gas-dynamical, thermal-engineering, electric-arc rocks; physical and material testing laboratories. The following investigations are carried out on this base beginning with 1983: a behaviour of the fuel elements and the fuel assemblies reactors with water and liquid metal coolants on transition and emergency conditions; processes, accompanied the melting and the interaction with water of meltdown of materials composition of the active zone of WWER reactor; processes of the outcome from fuel and the fission products dissemination. It is presented the constructions of the experimental devices for researches of heavy accidents and the results of carried out reactor investigations

  20. 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.

  1. 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

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

    CERN Document Server

    Dubrovin, Daria; van Veldhuizen, Eddie; Ebert, Ute; Yair, Yoav; Price, Colin; 10.1029/2009JA014851

    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 morphology are investigated for sprites on Venus and Jupiter; they are quite similar to those on earth, but light emissions in the visible range are fainter by two orders of magnitude. The discharge spectra are measured; they are dominated by the minority species N2 on Venus, while signatures of both species are found on Jupiter-like planets. The spectrum of a fully developed spark on Venus is measured. We show that this spectrum is significantly different from the expected sprite spectrum.

  3. Experimental and theoretical investigation of pulsed plasma thrusters

    Science.gov (United States)

    Kamhawi, Hani

    An experimental and theoretical effort was carried out to investigate and explore various design modifications to improve pulsed plasma thruster (PPT) performance in the energy range between 5 and 60 J. Experimentally, a benchmark PPT was fabricated, and its performance evaluated and found to be comparable to previous flight type PPTs. A thermal management study to determine and elucidate energy loss mechanisms occurring in PPTs was conducted. It was determined that Teflon surface temperatures in excess of 370°K were attained during steady state thruster operation after the current pulse has ended contributing to the "late time ablation" of Teflon molecules. Also, radiation losses from the PPT structure accounted for approximately 50% of the thruster's stored energy. An inductively-driven plasma-actuated PPT was designed and fabricated to evaluate and investigate the effect of changing the discharge current waveform on PPT performance. A 1 muH inductor was used but resulted in reduced discharge current peaks and reduced Teflon ablation; this resulted in low thrust efficiency. In addition, the crowbar electrode placement contributed to the thrust degradation of the thruster since it resulted in a lateral JXB force that was not directed along the thrust axis. Coaxial inverse-pinch PPT configurations were designed, fabricated, and tested in an attempt to achieve efficient mass utilization. Axisymmetric discharge current operation was successfully achieved. Experimental and MACH2 predicted enclosed current contours agreed for 20 and 30 J thruster operation. Comparisons between the experimental and theoretically determined ablation rates indicated good agreement for 20 J but not for 30 J thruster operation. For 20 J, the temperature of the Teflon propellant surface never exceeded 6730K, thus indicating that no "late time ablation" due to Teflon molecule decomposition was occurring. For the 30 J thruster operation the MACH2 predicted ablation rate magnitude was only 40% of the experimentally measured value. Analysis of the temperature profile found that the temperature in the Teflon solid exceeded 673°K; this resulted in additional mass ablation after the current pulse has ended. To account for the difference between the experimental and theoretical ablation rates, it was found that Teflon decomposition occurs for Teflon temperatures above 705°K. Coaxial inverse-pinch PPT thrust efficiency of 5.3% was achieved at a specific impulse of 2420 s for 20 J thruster operation. This 150% improvement in specific impulse over the 20 J benchmark PPT operation is an indication of improved mass utilization.

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

    Science.gov (United States)

    Trumper, Ricardo; Gelbman, Moshe

    2000-01-01

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

  5. Critical Mass Laboratory Solutions Precipitation, Calcination, and Moisture Uptake Investigations

    International Nuclear Information System (INIS)

    Laboratory work was conducted at Pacific Northwest National Laboratory and the Plutonium Process Support Laboratory of the Plutonium Finishing Plant (PFP) to study flowsheet conditions to selectively precipitate plutonium oxalate from uranium-bearing Critical Mass Laboratory (CML) solutions in the PFP precipitation apparatus and to dry and calcine the resulting filtercake to generate a stable plutonium oxide bearing powder (as judged by loss-on-ignition measurements) in the ambient humidity of the remote mechanical C (RMC) line in the PFP. Based on these studies with simulated and genuine CML solutions and various constituent materials, process conditions were recommended to the PFP under which the product powders can reasonably be expected to pass the DOE-STD-3013 moisture criterion when packaged in the RMC line at relative humidity up to 80%

  6. Critical Mass Laboratory Solutions Precipitation, Calcination, and Moisture Uptake Investigations

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Sinkov, Sergey I.; McNamara, Bruce K.; Jones, Susan A.; Barney, Gary S.; Schmidt, Andrew J.; Sell, Rachel L.

    2002-06-03

    Laboratory work was conducted at Pacific Northwest National Laboratory and the Plutonium Process Support Laboratory of the Plutonium Finishing Plant (PFP) to study flowsheet conditions to selectively precipitate plutonium oxalate from uranium-bearing Critical Mass Laboratory (CML) solutions in the PFP precipitation apparatus and to dry and calcine the resulting filtercake to generate a stable plutonium oxide bearing powder (as judged by loss-on-ignition measurements) in the ambient humidity of the remote mechanical C (RMC) line in the PFP. Based on these studies with simulated and genuine CML solutions and various constituent materials, process conditions were recommended to the PFP under which the product powders can reasonably be expected to pass the DOE-STD-3013 moisture criterion when packaged in the RMC line at relative humidity up to 80%.

  7. 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.

  8. Theoretical and experimental investigations of harp's sympathetic modes

    OpenAIRE

    Le Carrou, Jean-loi?c; Gautier, Franc?ois; Badeau, Roland

    2007-01-01

    The harp is composed of a soundboard, a cavity with soundholes and 47 strings. When one string is plucked, other strings are excited via the soundboard. This phenomenon, called sympathetic vibrations, was investigated in a recent paper [1], both theoretically and experimentally using an ersatz of string instrument, composed of 2 strings connected to a beam clamped at both ends. In order to extend the analysis to the case of the harp, an analytical model of a set of 35 strings coupled to a bea...

  9. Experimental Investigation of the Momentum Method for Determining Profile Drag

    Science.gov (United States)

    Goett, Harry J

    1939-01-01

    Report presents the results of an experimental investigation conducted in the full-scale tunnel to determine the accuracy of the Jones and the Betz equations for computing profile drag from total and static pressure surveys in the wake of wings. Surveys were made behind 6 by 8-foot airfoils of the NACA 0009, and 0018 sections at zero lift and behind the NACA 0012 at positive lifts. The surveys were made at various spanwise positions and at distances behind the airfoil ranging from 0.05c to 3.00c.

  10. 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.)

  11. 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.

  12. Experimental investigation and model development for a harmonic drive transmission

    International Nuclear Information System (INIS)

    Harmonic drive transmissions (HDTs) are compact, low-backlash, high-ratio, high-resolution rotary motion transmissions. One application to benefit from these attributes is the revolute joint robot. Engineers at the Advanced Photon Source (APS) are investigating the use of this type of robot for the positioning of an x-ray detector; understanding the properties of the robot components is crucial to modeling positioner behavior. The robot bearing elements had been investigated previously, leaving the transmission as the missing component. While the benefits of HDTs are well known, the disadvantages, including fluctuating dissipation characteristics and nonlinear stiffness, are not understood as well. These characteristics can contribute uncontrolled dynamics to the overall robot performance. A dynamometer has been constructed at the APS to experimentally measure the HDT's response. Empirical torque and position data were recorded for multiple transmission load cases and input conditions. In turn, a computer model of the dynamometer HDT system was constructed to approximate the observed response.

  13. 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.

  14. 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.

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

    Science.gov (United States)

    Dejardin, S.; Thibaud, S.; Gelin, J. C.

    2007-05-01

    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.

  16. Computational and Experimental Investigations of Boundary Layer Tripping

    Directory of Open Access Journals (Sweden)

    M.R Heidari

    2010-01-01

    Full Text Available Supersonic flow over a tapered body of revolution has been investigated both experimentally and numerically. The experimental study consisted of a series of wind tunnel tests on an ogive-cylinder body. Static pressure distributions on the body surfaces at several longitudinal cross sections, as well as the boundary layer profiles at various angles of attack have been measured. Further, the flow around the model was visualized using Schlieren technique. Tests with a natural development of the boundary layer and with tripping were also carried out. All tests were conducted in the trisonic wind tunnel of Qadr Research Center. Our results show that artificial boundary layer tripping has minor effect on the static surface pressure distribution (depending on its diameter and installation location, while the changes in total pressure around the body were significant. Tripping the boundary layer increased its thickness, changed its profile particularly near the body surface. Two oblique shock waves were formed in the front and behind the trip wire. In this study, using multi-block grid, the thin layer Navier-Stokes (TLNS equations were solved around the above models. Also patched method was used near the interfaces. Good agreements were achieved when the numerical results were compared with the corresponding experimental data.

  17. Mineralogical-geochemical effects during geological storage of CO2 : experimental investigations and geochemical modeling

    OpenAIRE

    Sebastian Fischer

    2013-01-01

    In order to analyze mineralogical-geochemical changes occurring in whole rock reservoir samples (Stuttgart Formation) from the Ketzin pilot CO2 storage site, Brandenburg/Germany as well as to investigate single fluid-mineral reactions laboratory experiments and geochemical modeling were performed. The whole rock core samples of the Stuttgart Formation were exposed to synthetic brine and pure CO2 at experimental P-T conditions and run durations of 5.5 MPa/40 °C/40 months for sandstone and 7.5 ...

  18. Some problems of a technique of experimental investigations of cosmic ray variations

    International Nuclear Information System (INIS)

    Methodological aspects of cosmic ray (CR) variation investigations have been discussed. The experimental data on latitudinal intensity distribution of the total neutron component of CRs and ''stars'' of neutrons with different multiples were obtained from 1975 to 1977 in CR laboratory on the research ship ''Akademic Kurchatov''. Neutron component bond coefficients having different values and varying insignificantly in minimum solar activity years are given for that period. The shore effect has been examined. CR-CR count rate variation due to the CR interaction with a heterogeneous environment (air-soil-water) the value of which varies from 12 to 16%

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

    Science.gov (United States)

    Adam C. Hall (Smith College; )

    2003-11-01

    This article describes the development of a course which introduces students to issues of animal ethics, experimentation, and an Animal Care Facility. The experiments enable the students to gain confidence in collecting data, compiling large data sets, handling spreadsheets and graphing, applying appropriate statistics, and writing accurate and concise scientific reports in journal article format.

  20. Experimental investigation of the Ce-Cu phase diagram

    International Nuclear Information System (INIS)

    Highlights: ? We re-investigated the Ce-Cu phase diagram by means of experimental measurements. ? Seven temperatures for the invariant reactions were confirmed, while two temperatures for the invariant reactions were revised. ? The updated Ce-Cu phase diagram was presented in this work. - Abstract: The binary Ce-Cu system has been re-investigated via the selected eighteen key alloys by means of the differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM) with energy dispersive X-ray analysis techniques. Five intermetallic compounds, Cu6Ce, Cu5Ce, Cu4Ce, Cu2Ce, and CuCe, have been confirmed. Cu6Ce and Cu2Ce melt congruently at 947 deg. C and 810 deg. C, respectively. Cu5Ce, Cu4Ce, and CuCe are formed through peritectic reactions, L + Cu6Ce ? Cu5Ce at 799 deg. C, L + Cu5Ce ? Cu4Ce at 792 deg. C, and L + Cu2Ce ? CuCe at 492 deg. C, respectively. Three eutectic reactions, L ? (Cu) + Cu6Ce at 879 deg. C, L ? Cu4Ce + Cu2Ce at 753 deg. C, and L ? CuCe + (?Ce) at 407 deg. C, have been observed. One catatectic reaction, (?Ce) ? L + (?Ce) at 702 deg. C, was determined. According to the present experimental results, the Ce-Cu phase diagram is revised.

  1. Optical actuation of silicon cantilevers: modelling and experimental investigation

    Science.gov (United States)

    Jiang, Fei; Keating, Adrian; Martyuink, Mariusz; Silva, Dilusha; Faraone, Lorenzo; Dell, John M.

    2013-05-01

    This paper reports on the modeling and experimental investigation of optical excitation of silicon cantilevers. In this work, the silicon cantilevers fabricated have dimensions with width of 15 ?m, thickness of 0.26 ?m, and variable length from 50 to 120 ?m. In order to investigate the effect of the laser modulation frequency and position on the temperature at the anchor edge and displacements at the tip of cantilevers, a transient thermal ANSYS simulation and a steady-state static thermal mechanical ANSYS simulation were undertaken using a structure consisting of silicon device layer, SiO2 sacrificial layer and silicon substrate. The dynamic properties of silicon cantilevers were undertaken by a series of experiments. The period optical driving signal with controlled modulation amplitude was provided by a 405 nm diode laser with a 2.9 ?W/?m2 laser power and variable frequencies. The laser spot was located through the longitude direction of silicon cantilevers. In factor, simulation results well matched with experimental observation, including: 1) for untreated silicon cantilevers, the maximum of displacement is observed when the laser beam was located half a diameter way from the anchor on the silicon suspended cantilever side; 2) for the both cantilevers, maximum displacement occurs when the optical actuation frequency is equal to the resonant frequency of cantilevers. Understanding the optical excitation on silicon cantilevers, as waveguides, can potentially increase sensing detection sensitivity (ratio of transmission to cantilever deflection).

  2. 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.

  3. 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

  4. The Grimsel (Switzerland) migration experiment: integrating field experiments, laboratory investigations and modelling

    Science.gov (United States)

    Hadermann, Jörg; Heer, Walter

    1996-02-01

    For several years tracer migration experiments are performed at Nagra's Grimsel Test Site in the Swiss Alps as a joint undertaking of Nagra, PNC and PSI. The aim is to develop methods for field experiments at possible sites for nuclear waste repositories and to test radionuclide transport models. A hydraulic dipole field is generated in a well-defined fracture zone in granite. The tracers used are non-sorbing (uranine, 3He, 4He, 82Br -, 123I -), mildly sorbing ( 22Na +, 24Na +), and more strongly sorbing ( 85Sr 2+, 86Rb +, 134Cs +, 137Cs +). These experiments have been complemented by extensive laboratory investigations on petrography, on water-rock and nuclide-rock interaction as well as by migration experiments with bore cores. The main questions addressed are: What are the relevant geometric factors and mechanisms for transport, how well can breakthrough curves be extrapolated from one dipole arrangement to another, which parameters are scale dependent, is there a difference in sorption values between laboratory and field experiments or between static and dynamic experiments. Evaluating the experimental results for the non-sorbing uranine and the mildly sorbing tracers sorption, Strontium, we show that a consistent picture of tracer transport, and specifically of tracer sorption, is obtained when exploiting all available experimental information and using not too simplistic models.

  5. 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/?) 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 ?1, and ?2. (?1 > ?2) 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

  6. 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.

  7. 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

  8. Laboratory experimental studies of seismic scattering from fractures

    Science.gov (United States)

    Zhu, Zhenya; Burns, Daniel R.; Brown, Steve; Fehler, Michael

    2015-04-01

    Laboratory acoustic measurements are performed with Lucite fracture models to understand the scattering characteristics of a seismic wave in a fracture zone. The fracture models include single, dual, and multiple fracture zones with varying fracture apertures, height, and spacing. Fractures are created by both very fine saw cuts and laser-etching. A vertical P-wave source is used with vertical (P) and horizontal (S) receivers to measure the reflected and scattered wavefield as a function of offset and azimuth relative to the fracture orientation. The amplitude of the arrival generated from the fracture tips is proportional to the fracture aperture. Comparison of traces from a single fracture and a dual fracture model indicates that multiple scattering is an important component of the scattered wave signal in fracture systems. In the fracture zone models, the PP and PS scattered wave energy varies azimuthally providing multiple methods for fracture orientation estimation. In particular, PS scattering on the transverse component is a maximum at 45°, while the PS inline component shows a systematic increase in amplitude as the azimuth approaches 90°. Total scattered wave energy is also observed to vary with changes in fracture aperture and height providing a possible means to estimate fracture zone flow capacity from seismic data.

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

    International Nuclear Information System (INIS)

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

  10. 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.

  11. Laboratory and field investigations of marsh edge erosion

    Science.gov (United States)

    This chapter presents the laboratory experiments and field observations of marsh edge erosion. The marsh retreat rate in a field study site in Terrebonne Bay, Louisiana, was measured using GPS systems and aerial photographs. The wave environment was also measured in order to correlate the marsh edge...

  12. 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…

  13. 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.

  14. 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

  15. Experimental Investigation of High Temperature Superconducting Imaging Surface Magnetometry

    International Nuclear Information System (INIS)

    The behavior of high temperature superconducting quantum interference devices (SQUIDs) in the presence of high temperature superconducting surfaces has been investigated. When current sources are placed close to a superconducting imaging surface (SIS) an image current is produced due to the Meissner effect. When a SQUID magnetometer is placed near such a surface it will perform in a gradiometric fashion provided the SQUID and source distances to the SIS are much less than the size of the SIS. We present the first ever experimental verification of this effect for a high temperature SIS. Results are presented for two SQUID-SIS configurations, using a 100 mm diameter YBa2Cu3O7-? disc as the SIS. These results indicate that when the current source and sensor coil (SQUID) are close to the SIS, the behavior is that of a first-order gradiometer. The results are compared to analytic solutions as well as the theoretical predictions of a finite element model

  16. Torsional Performance of Wind Turbine Blades : Part I: Experimental Investigation

    DEFF Research Database (Denmark)

    Berring, Peter; Branner, Kim

    2007-01-01

    The complete 3D static responses of two different eight meter long wind turbine blade sections were tested. To experimentally investigate the 3D response, an advanced 3D digital optical deformation measuring system (ARAMIS 2M and 4M) was applied in this work. This system measures the full-field displacements (ux, uy and uz) of the blade surface. A least squares algorithm was developed, which fits a plane through each deformed cross section, and defines a single set of displacements and rotations (three displacements and rotations) per cross section. This least squares algorithm was also used to accommodate problems with a flexible boundary condition by determining the displacements and rotations for a cross section near the boundary. These displacements and rotations are subtracted from all other cross sections along the blade and thereby making the blade section fully fixed at the chosen cross section near the boundary.

  17. 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.

  18. 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

  19. 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.

  20. A preliminary experimental investigation into lateral pedestrian-structure interaction

    DEFF Research Database (Denmark)

    Ingólfsson, Einar Thór; Georgakis, Christos

    2008-01-01

    This paper presents results from a preliminary experimental study on lateral human-structure dynamic interaction on footbridges using an instrumented platform. The platform has a natural frequency within the range of an average pedestrian and consists of a suspended concrete girder. With a length 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 identified and are presented herewith. Finally, the results from this study are compared to previous full-scale as well as section model measurements.

  1. An experimental investigation of flow mixing on thrust ejection efficiency

    Science.gov (United States)

    Morfitt, Donald J., Jr.

    1988-12-01

    The purpose of this study was to determine the effect flow mixing has on the thrust augmentation of an ejector. The experimental studies were divided into four phases. The four phases were baseline verification, a nozzle tip inclination study, a primary flow pulsing study, and a study of the quality of the ejector. The baseline verification study showed that thrust augmentation is dependent upon the injection angle and height of the primary nozzles. The nozzle tip inclination study investigated the effects of having the tips inclined from the inlet surface of the ejector. The nozzle tips were inclined in four different configurations. The different configurations established a baseline or attempted to promote flow mixing and swirling.

  2. Experimental investigation of the asymmetric body vortex wake

    Science.gov (United States)

    Oberkampf, W. L.; Shivananda, T. P.; Owen, F. K.

    1980-01-01

    An experimental investigation of the asymmetric body vortex wake of a circular cylinder in high subsonic flow is presented. Laser velocimeter, force and moment, and surface hot wire measurements were obtained for a freestream Mach number of 0.6 and Reynolds number (based on body diameter) of 0.62 x 10 to the 6th. Two component laser velocimeter measurements were made at three body cross-flow planes, x/d = 4, 8, and 12, and angles of attack of 25, 35, and 45 deg. Laser vapor screen photographs were also obtained at these body stations and angles of attack. Surface hot wire measurements were used to determine if any vortex switching occurred at various angles of attack of the body. The laser velocimeter measurements are related to the vapor screen photographs and side force measurements. These results show that more than one asymmetric body vortex wake configuration can exist for the same angle of attack and body roll angle.

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

    International Nuclear Information System (INIS)

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

  4. 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.

  5. Surface plasmon resonance of Ag organosols: Experimental and theoretical investigations

    Directory of Open Access Journals (Sweden)

    Vodnik Vesna

    2012-01-01

    Full Text Available The aim of this paper is to investigate and compare the changes in surface plasmon resonance (SPR of silver (Ag hydrosol and organosols obtained by experimental and theoretical approaches. Silver nanoparticles (Ag NPs of 5 ± 1.5 nm in diameter were prepared in water by reduction of silver nitrate with sodium borohydride. Nanoparticles were subsequently transferred into different organic solvents (chloroform, hexane, toluene, 1,2-dichlorobenzene using oleylamine as a transfer agent. These solvents were chosen because of the differences in their refractive indices. Using UV-Vis absorption spectrophotometry and transmission electron microscopy (TEM, we confirmed that there were no shape and size changes of the nanoparticles upon the transfer to the organic phase. The absorption spectra of the obtained Ag organosols showed only changes in the position of SPR band depending on dielectric property of the used solvent. To analyze these changes, absorption spectra were modelled using Mie theory for small spherical particles. The experimental and theoretical resonance values were compared with those predicted by Drude model and its limitations in the analysis of absorption behavior of Ag NPs in organic solvents were briefly discussed.

  6. Experimental investigation of coarse particle conveying in pipes

    Science.gov (United States)

    Vlasak, Pavel; Chara, Zdenek; Konfrst, Jiri; Krupi?ka, Jan

    2015-05-01

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

  7. 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

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

    International Nuclear Information System (INIS)

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

  9. Thermal mirror spectrometry: An experimental investigation of optical glasses

    Science.gov (United States)

    Zanuto, V. S.; Herculano, L. S.; Baesso, M. L.; Lukasievicz, G. V. B.; Jacinto, C.; Malacarne, L. C.; Astrath, N. G. C.

    2013-03-01

    The Thermal mirror technique relies on measuring laser-induced nanoscale surface deformation of a solid sample. The amplitude of the effect is directly dependent on the optical absorption and linear thermal expansion coefficients, and the time evolution depends on the heat diffusion properties of the sample. Measurement of transient signals provide direct access to thermal, optical and mechanical properties of the material. The theoretical models describing this effect can be formulated for very low optical absorbing and for absorbing materials. In addition, the theories describing the effect apply for semi-infinite and finite samples. In this work, we apply the Thermal mirror technique to measure physical properties of optical glasses. The semi-infinite and finite models are used to investigate very low optical absorbing glasses. The thickness limit for which the semi-infinite model retrieves the correct values of the thermal diffusivity and amplitude of the transient is obtained using the finite description. This procedure is also employed on absorbing glasses, and the semi-infinite Beer-Lambert law model is used to analyze the experimental data. The experimental data show the need to use the finite model for samples with very low bulk absorption coefficients and thicknesses L 1.0 mm in this case. In addition, the physical properties of the samples were calculated and absolute values derived.

  10. 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.

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

    Science.gov (United States)

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

    2015-06-01

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

  12. 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.

  13. Unsteady Ejector Performance: an Experimental Investigation Using a Pulsejet Driver

    Science.gov (United States)

    Paxson, Daniel E.; Wilson, Jack; Dougherty, Kevin T.

    2002-01-01

    An experimental investigation is described in which thrust augmentation and mass entrainment were measured for a variety of simple cylindrical ejectors driven by a gasoline-fueled pulsejet. The ejectors were of varying length, diameter, and inlet radius. Measurements were also taken to determine the effect on performance of the distance between pulsejet exit and ejector inlet. Limited tests were also conducted to determine the effect of driver cross-sectional shape. Optimal values were found for all three ejector parameters with respect to thrust augmentation. This was not the case with mass entrainment, which increased monotonically with ejector diameter. Thus, it was found that thrust augmentation is not necessarily directly related to mass entrainment, as is often supposed for ejectors. Peak thrust augmentation values of 1.8 were obtained. Peak mass entrainment values of 30 times the driver mass flow were also observed. Details of the experimental setup and results are presented. Preliminary analysis of the results indicates that the enhanced performance obtained with an unsteady jet (primary source) over comparably sized ejectors driven with steady jets is due primarily to the structure of the starting vortex-type flow associated with the former.

  14. 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

  15. 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.)

  16. Review Of Experimental Studies Investigating The Rate Of Strontium And Actinide Adsorption By Monosodium Titanate

    International Nuclear Information System (INIS)

    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..

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

    Directory of Open Access Journals (Sweden)

    André Paulo Afonso de

    2000-01-01

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

  18. 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.

  19. Discrete optimization of isolator locations for vibration isolation systems: An analytical and experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Ponslet, E.R.; Eldred, M.S. [Sandia National Labs., Albuquerque, NM (United States). Structural Dynamics Dept.

    1996-05-17

    An analytical and experimental study is conducted to investigate the effect of isolator locations on the effectiveness of vibration isolation systems. The study uses isolators with fixed properties and evaluates potential improvements to the isolation system that can be achieved by optimizing isolator locations. Because the available locations for the isolators are discrete in this application, a Genetic Algorithm (GA) is used as the optimization method. The system is modeled in MATLAB{trademark} and coupled with the GA available in the DAKOTA optimization toolkit under development at Sandia National Laboratories. Design constraints dictated by hardware and experimental limitations are implemented through penalty function techniques. A series of GA runs reveal difficulties in the search on this heavily constrained, multimodal, discrete problem. However, the GA runs provide a variety of optimized designs with predicted performance from 30 to 70 times better than a baseline configuration. An alternate approach is also tested on this problem: it uses continuous optimization, followed by rounding of the solution to neighboring discrete configurations. Results show that this approach leads to either infeasible or poor designs. Finally, a number of optimized designs obtained from the GA searches are tested in the laboratory and compared to the baseline design. These experimental results show a 7 to 46 times improvement in vibration isolation from the baseline configuration.

  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. The three-spined stickleback-Schistocephalus solidus system: an experimental model for investigating host-parasite interactions in fish.

    Science.gov (United States)

    Barber, I; Scharsack, J P

    2010-03-01

    Plerocercoids of the pseudophyllidean cestode Schistocephalus solidus infect the three-spined stickleback Gasterosteus aculeatus, with important consequences for the biology of host fish. Techniques for culturing the parasite in vitro and generating infective stages that can be used to infect sticklebacks experimentally have been developed, and the system is increasingly used as a laboratory model for investigating aspects of host-parasite interactions. Recent experimental laboratory studies have focused on the immune responses of hosts to infection, the consequences of infection for the growth and reproductive development of host fish and the effects of infection on host behaviour. Here we introduce the host and the parasite, review the major findings of these recent experimental infection studies and identify further aspects of host parasite interactions that might be investigated using the system. PMID:19835650

  2. 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…

  3. An experimental facility to investigate missile impact on small scale concrete elements

    International Nuclear Information System (INIS)

    The necessity to design nuclear power plants for extreme load conditions is now well recognised. These load conditions include aircraft and missile impact. The behaviour of structures under such conditions and the extent of influence of various parameters is not yet clearly defined. Research is still in progress in such areas to assess the local and global response of structures subjected to impact. One possible avenue of research is experimental investigation. Scaled testing of the impact problem has also been proved to give sufficiently accurate results. However the fact that velocity of impact cannot be scaled down according to the dynamic scaling laws has confined the investigations to laboratories which have a facility to launch high velocity projectiles. UKAEA in Winfrith, UK, and, Meppen and Foulness in Germany are three of the laboratories where such launching facilities are available. Models scaled to 1/20th to 1/25th of the prototype are reasonably accurate. Impact, being a highly dynamic phenomenon with transient forces lasting only a few milliseconds requires instrumentation with good dynamic response. This paper explains in detail an experimental setup developed to test small scale specimens of slabs and shells under missile impact at a velocity of around 200m/s

  4. 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

  5. Experimental investigation of kinetics and rheology during diagenesis

    Energy Technology Data Exchange (ETDEWEB)

    Liou, J.G.; Hacker, B.R.

    1998-09-01

    Two processes of enormous economic consequence occur within the upper to middle crust: the formation, migration, entrapment, and degradation of hydrocarbons, and hazardous seismicity. Substantial scientific evidence suggests that both these processes are influenced by devolatilization reactions during diagenesis. However, surprisingly few laboratory studies have been conducted on materials actively undergoing low-grade metamorphism or diagenesis. Because of this, there exists no suitable basis for understanding the rates at which devolatilization occurs, and what effects this process has on deformation at shallow to moderate depths in the crust. The authors are conducting a coordinated deformation and kinetic study of an important devolatilization reaction: the breakdown of laumontite. Laumontite is a common zeolite whose equilibrium phase relations and room-temperature frictional behavior are well understood. Besides serving as a model system for more complicated rocks, laumontite is an important mineral in its own right, particularly for hydrocarbon fields in sandstones and for fault zones in the crust. Hydrostatic experiments are being conducted to investigate the kinetics and mechanism of laumontite dehydration, and triaxial deformation experiments will enable characterization of the effect of differential stress on the reaction and the effect of synkinematic dehydration on the mechanical behavior of rock. The authors anticipate results of significant import for hydrocarbon exploration and recovery and for understanding the strength and seismic potential of crustal fault zones.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. An experimental investigation of loop seal clearings in SBLOCA tests

    International Nuclear Information System (INIS)

    Highlights: • An experimental study of the loop seal clearing in the SBLOCAs was performed. • Loop seal behaviors with related parameters were investigated. • The mechanism of initiation of a loop seal clearing was suggested. • The sustaining of a loop seal clearing without refilling was evaluated. - Abstract: An investigation of the loop seal clearing (LSC) in a small-break loss-of-coolant accident (SBLOCA) for direct vessel injection (DVI) line and cold leg (CL) breaks was performed. The behavior of an LSC appears to be closely related to the break location and break size. In the tests of SBLOCAs, a loop seal or cross-over leg (COL) in the broken loop was cleared first, and the number of loop seals cleared was dependent on the break size. The larger the break size was, the more the loop seals or COLs that were cleared. The location of the LSCs appeared to have a consistent behavior under each scenario. In the SBLOCA tests, the downcomer water level just before an LSC was a very important parameter to the peak cladding temperature (PCT). The initiation of an LSC might not be related to the existing flooding condition, but to the magnitude of the pressure difference between the reactor upper head and downcomer, which is sufficient to push the upflow leg of a COL. The sustaining of an LSC without refilling was evaluated using the test data and existing flooding conditions

  11. 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

  12. Experimental investigation of flow instabilities in a laminar separation bubble

    Science.gov (United States)

    Simoni, D.; Ubaldi, M.; Zunino, P.

    2014-06-01

    The present paper reports the results of a detailed experimental study aimed at investigating the dynamics of a laminar separation bubble, from the origin of separation up to the breakdown to turbulence of the large scale coherent structures generated as a consequence of the Kelvin-Helmholtz instability process. Measurements have been performed along a flat plate installed within a double contoured test section, designed to produce an adverse pressure gradient typical of Ultra-High-Lift turbine blade profiles, which induces the formation of a laminar separation bubble at low Reynolds number condition. Measurements have been carried out by means of complementary techniques: hot-wire (HW) anemometry, Laser Doppler Velocimetry (LDV) and Particle Image Velocimetry (PIV). The high accuracy 2-dimensional LDV results allow investigating reverse flow magnitude and both Reynolds normal and shear stress distributions along the separated flow region, while the high frequency response of the HW anemometer allows analyzing the amplification process of flow oscillations induced by instability mechanisms. PIV results complement the flow field analysis providing information on the generation and evolution of the large scale coherent structures shed as a consequence of the separated shear layer roll-up, through instantaneous velocity vector maps. The simultaneous analysis of the data obtained by means of the different measuring techniques allows an in depth view of the instability mechanisms involved in the transition/reattachment processes of the separated shear layer.

  13. 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

  14. Theoretical and Experimental Investigation of Liquid Metal MHD Power Generation

    International Nuclear Information System (INIS)

    Liquid metal magnetohydrodynamic power generation for space is studied. Closed- loop circulation of liquid metal without moving mechanical parts, and generation of electric power from the circulating metal, have been investigated analytically and experimentally, and the attainable cycle efficiencies have been calculated. Recent literature has pointed out the possibility of efficient a.c. generators with liquid metal as the working fluid, and this type of generator is under study. Analysis indicates that efficiencies up to 65% are attainable in a travelling-wave induction generator at the available liquid metal velocities of 100-200 m/sec, provided the generator has a length/gap ratio of no more than 50 for low friction loss, has an electrical length of no more than three wavelengths for low winding loss, and has end-effect compensation for cancelling finite-length effects in the power-generating region. The analysis leading to these conclusions is presented. The type of end-effect correction being studied is the ''compensating-pole'' technique in which an oscillating magnetic field is applied to the fluid entering and leaving the generator to make the flux linkages within the generator the same as those in a rotating or ''infinite'' generator. An experimental one-wavelength generator employing compensating poles has been fabricated, and empty-channel magnetic field measurements have been completed in preparation for tests with NaK. Two types of field measurements were NaK. Two types of field measurements were made: d.c. measurements to determine the field profile as a function of phase angle and a.c. measurements to investigate the synchronization of the compensating poles with the travelling wave. The d.c. results showed that the flux linkages in the power generating region can be held close to those in a rotating machine, and the a.c. results showed that the compensating poles can be accurately synchronized with the travelling wave through transformer coupling. The component efficiencies from the analyses and experiments were combined to predict the cycle efficiencies possible in space applications. The calculations included the different liquid MHD cycles and working fluids that have been proposed in the literature, and these cycles are reviewed and compared. A possible limitation on lifetime at the 1100-1500°K temperatures needed for a space power plant is erosion by the high velocity liquid metal, and this problem is being investigated in a 70 m/sec lithium loop. (author)

  15. 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)

  16. Experimental investigation of hot electrons inside cavity target

    International Nuclear Information System (INIS)

    In the interaction of intense laser-plasma, hot electrons, which can preheat the core of the fuel and lower the compression efficiency, are produced by collective processes such as stimulated Raman Scattering (SRS), resonance absorption (RA), two plasma decay (TPD) and ion acoustic decay (IAD). It is very important to study hot electrons experimentally and theoretically. The spectrum and total energy of hard X-rays outside the cavity targets have been measured for many years. In order to correct theoretical model and improve accuracy of calculating the total energy of hot electrons in cavities, it is urgent to identify the traveling direction of hot electrons and the regions of hard X-rays generation. In the experiment reported, specific cavities was designed to investigate the angular distribution of hot electrons in cavity and the region of hard X-ray generation. Experiments were conduced on Shengguang high power laser facility. The cavity target was irradiated by one beam laser (? = 1.06 ?m, EL = 450?550 J, ?? 0.8 ns, IL ?1015 W·cm-2). A ten channel filter fluorescence spectrometer and an array of separate GaAs photoconductor were used to measure the spectra, angular distribution, and total energy of hard X-rays, and the energy of stimulated Raman scattering light was also measured for comparison. From the specific structure of cavities and the experimental results, the following two main results were inferred: two main results were inferred: (1) Most of the hot electrons in cavity are inclined to travel along the direction of laser wave vector, not isotropically. (2) Hard X-rays were mainly produced by Bremsstrahlung effect of hot electrons' collision with gold cavity wall

  17. 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)

  18. Photoperiodic Treatments in Morning Glory: A Laboratory Investigation.

    Science.gov (United States)

    Madrazo, Gerry M., Jr.; Hounshell, Paul B.

    1978-01-01

    The Japanese morning glory, a short-day plant, is an excellent specimen for studying photoperiodism. This article gives ideas for investigations including the effects of hormones, light quality, and temperature. Preparation of the seed is also discussed. (BB)

  19. Experimental investigation of high temperature and high pressure coal gasification

    International Nuclear Information System (INIS)

    Highlights: ? Gasification kinetics at temperature up to 1600 °C and pressure up to 0.5 MPa. ? Experimental investigation of pyrolysis under realistic conditions. ? Experiments in lab-scale using three different setups. ? Comparison of lab-scale data to experimental results from a pilot-scale gasifier. -- Abstract: Pyrolysis and gasification behavior is analyzed at operation conditions relevant to industrial scale entrained flow gasifiers. A wire mesh reactor and the Pressurized High Temperature Entrained Flow Reactor (PiTER) are used to measure volatile yield of Rhenish lignite, a bituminous coal and German anthracite at high temperature and high pressure. In the wire mesh reactor at 1000 °C a significant influence of pressure on volatile yield is observed. For lignite the volatile yield (daf) decreases from 57 wt% at atmospheric pressure to 53 wt% at 5.0 MPa. In the same pressure interval the volatile yield of the bituminous coal strongly decreases, whereas no significant influence of pressure on the volatile yield of anthracite is detected. In entrained flow experiments (PiTER) at higher temperature and 0.5 MPa an enhanced devolatilization of the lignite is observed. At 1200 °C, the maximum volatile yield is 62 wt% and it increases to 67 wt% at 1400 °C. In entrained flow gasification experiments with Rhenish lignite a high level of conversion is measured at atmospheric pressure and at 0.5 MPa. At both pressures, coal conversion increases with temperature and residence time. The highest conversion of 96 wt% is achieved at a particle residence time of 1.3 s, at a temperature of 1600 °C, and a pressure of 0.5 MPa. The experimental results show a large influence of operation parameters on pyrolysis and gasification behavior of Rhenish lignite. The volatile release in the pyrolysis stage and the high level of conversion after a short residence time indicate that Rhenish lignite is suitable for gasification in an entrained flow reactor. The reactivities of char samples that are collected from the hot reaction zone of the PiTER are measured in a pressurized thermogravimetric analyzer (PTGA) at lower temperature (600–850 °C). The pyrolysis temperature in the entrained flow experiments significantly influences the reaction rate in the PTGA at lower temperature. With increasing pyrolysis temperature (1200–1600 °C) a continuous loss of reactivity is observed.

  20. 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)

  1. 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 construc and due its simplicity and rapid construction was recommended to be used in this diversion dam. (author)

  2. 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

  3. 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

  4. 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.

  5. Glulam-concrete composites: experimental investigation into the connection system

    Scientific Electronic Library Online (English)

    José Luiz, Miotto; Antonio Alves, Dias.

    2011-03-01

    Full Text Available Timber-concrete composite structures work appropriately when a suitable connection system is included because the degree of interaction between the materials stiffs the structural system. Thereby, it is extremely important to improve the knowledge about their connection system. The purpose of this p [...] aper is to show the results obtained by experimental investigation into push-out shear tests of glulam-concrete specimens. The specimens were designed to simulate the behaviour of composite T beams and the connection system was constituted by steel hooks - got by the division of steel bars used in reinforced concrete members - and by perforated steel plates, both glued with epoxy adhesive. They were tested under shear forces with constant loading rate. Six specimens of each group were made, considering two different diameters for the hooks (8 and 10 mm) and 4.75 mm thick perforated steel plates. The stiffness reached by steel hooks confirms their suitability for the use in composite timber-concrete systems.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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...

  11. 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.

  12. Experimental investigation of hardfaced martensitic steel under slurry abrasion conditions

    International Nuclear Information System (INIS)

    Wear by slurry abrasion is a potential problem in engineering components subjected to particulate flow. The life of the components under slurry abrasive wear situations is primarily decided by operating conditions and the materials properties. Martensitic steels are widely used for abrasion resistant applications. The present work reports slurry abrasion response of hardfacing martensitic steel under a wide range of experimental conditions. The response data is generated using systematic and simultaneous variation of test parameters. The experiments were performed using silica sand slurry with different slurry concentration, particle size, sliding distance and load. The results of the investigation suggest that slurry concentration had relatively stronger effect than normal load. The wear volume loss exhibited an increasing trend with increasing severity of test parameters. An empirical equation is proposed to describe the interactive effect of the test parameters, abrasive particle properties and material property. SEM (Scanning Electron Microscope) studies revealed different morphology of the worn surfaces which was attributed to mild to severe slurry abrasion test conditions.

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

    DEFF Research Database (Denmark)

    Zhusubaliyev, Zhanybai; Mosekilde, Erik

    2006-01-01

    Numerical studies of higher-dimensional piecewise-smooth systems have recently shown how a torus can arise from a periodic cycle through a special type of border-collision bifurcation. The present article investigates this new route to quasiperiodicity in the two-dimensional piecewise-linear normal form map. We have obtained the chart of the dynamical modes for this map and showed that border-collision bifurcations can lead to the birth of a stable closed invariant curve associated with quasiperiodic or periodic dynamics. In the parameter regions leading to the existence of an invariant closed curve, there may be transitions between an ergodic torus and a resonance torus, but the mechanism of creation for the resonance tongues is distinctly different from that observed in smooth maps. The transition from a stable focus point to a resonance torus may lead directly to a new focus of higher periodicity, e.g., a period-5 focus. This article also contains a discussion of torus destruction via a homoclinic bifurcation in the piecewise-linear normal map. Using a dc–dc converter with two-level control as an example, we report the first experimental verification of the direct transition to quasiperiodicity through a border-collision bifurcation. ©2006 American Institute of Physics

  14. "They Sweat for Science": The Harvard Fatigue Laboratory and Self-Experimentation in American Exercise Physiology.

    Science.gov (United States)

    Johnson, Andi

    2014-08-20

    In many scientific fields, the practice of self-experimentation waned over the course of the twentieth century. For exercise physiologists working today, however, the practice of self-experimentation is alive and well. This paper considers the role of the Harvard Fatigue Laboratory and its scientific director, D. Bruce Dill, in legitimizing the practice of self-experimentation in exercise physiology. Descriptions of self-experimentation are drawn from papers published by members of the Harvard Fatigue Lab. Attention is paid to the ethical and practical justifications for self-experimentation in both the lab and the field. Born out of the practical, immediate demands of fatigue protocols, self-experimentation performed the long-term, epistemological function of uniting physiological data across time and space, enabling researchers to contribute to a general human biology program. PMID:25139499

  15. 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)

  16. Experimental Investigation of Piston Rings for Internal Combustion Engines

    DEFF Research Database (Denmark)

    Christiansen, Jens; Klit, Peder

    2007-01-01

    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. The following properties are measured: Oil film thickness - along liner (axial variation), oil film thickness - along piston ring (circumferential variation), piston tilt, temperature of piston rings and liner, pressure at piston lands and forces on piston rod. Since the frictional forces are small compared to the rest of the acting forces the main design idea is to fix the piston, while the cylinder liner moves. This approach makes it simple to measure the parameters mentioned above by putting the instrumentation in the piston. The aim of this paper is describe 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. 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 flow is discussed.

  17. Experimental and Computational Investigations of Strain Localization in Metallic Glasses

    Science.gov (United States)

    Bharathula, Ashwini

    Metallic glasses are metallic alloy systems with disordered atomic structure. Due to their unique amorphous structure, they exhibit an extraordinary set of properties that are ideal for a wide variety of applications ranging from electrical transformers, armor-piercing projectiles, sporting goods and fuel cells to precision gears for micromotors. In particular, owing to their exceptional mechanical properties like near-theoretical strength (1--3 GPa), large elastic strain range (2--3%), and unusual formability above the glass transition temperature, metallic glasses have tremendous potential in structural applications. Unfortunately, their unique structure also gives rise to significant limitations, such as limited ductility at room temperature due to rapid localization of plastic flow in shear bands. However, when the test volumes approach the size of a shear band nucleus (˜50--500 nm), it is believed that shear band formation and propagation can be constrained, leading to enhanced plasticity and failure strength. This study investigates the phenomenon of strain localization using both experimental and computational techniques. On the experimental front, sample size effects on strength, plasticity and deformation modes were explored in a Zr-based bulk metallic glass via micron- and sub-micron scale compression testing. Specimens with diameters ranging from 200 nm to a few microns were fabricated using Focused Ion Beam technique and were tested under uniaxial compression in a nanoindentation set-up with a flat punch tip. Effect of extrinsic factors like specimen geometry and machine stiffness on deformation behavior was discussed. Shear banding was shown to be more stable at this length scale than in macro-scale testing because of a smaller specimen to load frame stiffness ratio. It was found that as the specimen size is reduced to below 300 nm, the deformation mode changes from being discrete and inhomogeneous to more continuous flow including both localized and non-localized contributions at low strains. Moreover, the magnitude of strain bursts was found to decrease with decrease in specimen size. Furthermore, Weibull statistical analysis was performed to investigate the effect of specimen size on yield strength in this metallic glass. It was revealed that the dispersion in strengths increases dramatically with decrease in sample size, attributed to the size distribution of the defects responsible for shear banding. The findings are crucial in designing systems which promote plasticity in metallic glasses by suppressing the shear-band instability and also in direct application of these materials for structural purposes as small components in micro- and nano-scale systems. On the computational front, Molecular Dynamics (MD) simulations have been employed to generate Zr-Cu metallic glass structures. In order to analyze and better understand and visualize the concepts of "free" volume and flow defects in metallic glasses, an electron density model was developed as an upgrade to the traditional hard sphere approaches. Simple tension and shear modes of deformation were simulated using MD in Zr-Cu system, and role of open volume in deformation was studied using the electron density model. In uniaxial tension simulations, effect of temperature and deformation rate is examined, and the process of accumulation of free volume to the point of catastrophic failure is visualized using the Electron Density model. In shear simulations, we find that the as-quenched glass structures undergo homogeneous deformation and do not exhibit any strain localization. However, it is found that by incorporating a cylindrical void in the glass structure as a source of "free" volume, it is possible to induce strain localization. It was found that a critical void diameter of 8A was required to successfully initialize strain localization in this system.

  18. LABORATORY AND NUMERICAL INVESTIGATIONS OF RESIDENCE TIME DISTRIBUTION OF FLUIDS IN LAMINAR FLOW STIRRED ANNULAR PHOTOREACTOR

    Science.gov (United States)

    Laboratory and Numerical Investigations of Residence Time Distribution of Fluids in Laminar Flow Stirred Annular Photoreactor E. Sahle-Demessie1, Siefu Bekele2, U. R. Pillai1 1U.S. EPA, National Risk Management Research Laboratory Sustainable Technology Division,...

  19. 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.…

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

    Science.gov (United States)

    Ferrari, M; Vichi, A; Zarone, F

    2015-03-01

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

  1. 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...

  2. 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

  3. LABEXNET: un Laboratorio de Economía Experimental en Internet. [LABEXNET: Internet-based laboratory for experimental Economics

    Directory of Open Access Journals (Sweden)

    Galán Ordax, José Manuel

    2007-06-01

    Full Text Available Experimental Economists have designed over the years a wide range of scientific experiments that can be usefully employed nowadays as teaching aids. The interactive and participatory nature of such experiments serves as a motivation to students, stimulates their own thinking, and enhances their insights into the forces that drive economic markets: the aggregate interactions of economic agents within a market institution. Economic classroom games have been recognised as useful teaching tools for decades, and they have often produced surprising results and better understanding of market dynamics and institutions. Nowadays the new information technologies can be brought into play to conduct and analyse experimental games in unprecedented ways: using Internet-based tools, the design, execution and analysis of classroom games can be made considerably easier than traditionally. In this paper we introduce LABEXNET, a program designed to conduct Internet-based economic classroom games. LABEXNET is freely available to the academic community.. La Economía Experimental ha desarrollado diferentes experimentos que pueden ser aprovechados como una actividad docente en la enseñanza de la Economía. Su naturaleza activa y participativa motiva a los alumnos y estimula la reflexión y la mejor comprensión de algunos fenómenos económicos como el funcionamiento de los mercados, donde los resultados individuales dependen del conjunto de las decisiones de los agentes y de sus interacciones. Los experimentos económicos tienen ya una larga tradición, y han proporcionado resultados espectaculares y conclusiones ampliamente admitidas sobre la dinámica de mercados y el efecto de las instituciones económicas. Las nuevas tecnologías facilitan la realización y el análisis de estos experimentos. En este artículo presentamos LABEXNET, un programa informático para la realización de experimentos económicos por Internet puesto a libre disposición de la comunidad académica..

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. Blood circulation laboratory investigations with video are less investigative than instructional blood circulation laboratories with live organisms

    Science.gov (United States)

    Ms. Mildred A. Hoover (Curtin Univ Technol)

    2007-07-26

    Live organisms versus digital video of the organisms were used to challenge students' naive ideas and misconceptions about blood, the heart, and circulatory patterns. Three faculty members taught 259 grade 10 biology students in a California high school with students from diverse ethnolinguistic groups who were divided into 5 classes using microscopes (128 students) and 5 classes using digital video (131 students) to compare blood transport among invertebrates, fish, and humans. The "What Is Happening in this Class?" (WIHIC) questionnaire was used for assessment of microscope and video groups to detect students' perception of their learning environment following these teaching interventions. The use of microscopes had a clear effect on the perception of the investigative aspects of the learning environment that was not detected with the video treatment. Findings suggest that video should not replace investigations with live organisms.

  9. Neutron Elastic Scattering Cross Sections Experimental Data and Optical Model Cross Section Calculations. A Compilation of Neutron Data from the Studsvik Neutron Physics Laboratory

    International Nuclear Information System (INIS)

    Neutron elastic scattering cross section measurements have been going on for a long period at the Studsvik Van de Graaff laboratory. The cross sections of a range of elements have been investigated in the energy interval 1.5 to 8 MeV. The experimental data have been compared with cross sections calculated with the optical model when using a local nuclear potential

  10. 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.

  11. Current and emerging Legionella diagnostics for laboratory and outbreak investigations.

    Science.gov (United States)

    Mercante, Jeffrey W; Winchell, Jonas M

    2015-01-01

    Legionnaires' disease (LD) is an often severe and potentially fatal form of bacterial pneumonia caused by an extensive list of Legionella species. These ubiquitous freshwater and soil inhabitants cause human respiratory disease when amplified in man-made water or cooling systems and their aerosols expose a susceptible population. Treatment of sporadic cases and rapid control of LD outbreaks benefit from swift diagnosis in concert with discriminatory bacterial typing for immediate epidemiological responses. Traditional culture and serology were instrumental in describing disease incidence early in its history; currently, diagnosis of LD relies almost solely on the urinary antigen test, which captures only the dominant species and serogroup, Legionella pneumophila serogroup 1 (Lp1). This has created a diagnostic "blind spot" for LD caused by non-Lp1 strains. This review focuses on historic, current, and emerging technologies that hold promise for increasing LD diagnostic efficiency and detection rates as part of a coherent testing regimen. The importance of cooperation between epidemiologists and laboratorians for a rapid outbreak response is also illustrated in field investigations conducted by the CDC with state and local authorities. Finally, challenges facing health care professionals, building managers, and the public health community in combating LD are highlighted, and potential solutions are discussed. PMID:25567224

  12. EXPERIMENTAL INVESTIGATION OF DEFROST USING WARM LIQUID REFRIGERANT

    Science.gov (United States)

    This paper reports the results from laboratory tests of a low-temperature supermarket refrigeration system with two open and two reach-in display cases. Tests were performed at condensing temperatures ranging from 10 to 40 C and at an evaporating temperature of -34 C. The perfo...

  13. 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...

  14. 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.

  15. Experimental investigation of temperature fields in a synthetic jet

    Directory of Open Access Journals (Sweden)

    Dan?ová Petra

    2014-01-01

    experiment presents several challenges; therefore, to ensure the best precision possible, two experimental methods were used – digital holographic interferometry (DHI and thermo-anemometry in constant current mode as an auxiliary method to verify DHI.

  16. Experimental Investigation of Low Pressure Audio Frequency Discharge in Argon

    International Nuclear Information System (INIS)

    Experimental data obtained on audio frequency (100–10000 Hz) discharge in argon at four pressures 50, 60, 70, and 80 mTorr are presented. The data show significant changes of the discharge current waveform with frequency. These changes seem to be associated with the glow discharge profile and colour. An empirical model based on the assumption of a frequency-dependent breakdown voltage is used to describe the experimental data

  17. 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

  18. An experimental investigation of flow-induced cavity oscillations

    Science.gov (United States)

    Kegerise, Michael Aaron

    1999-11-01

    The flow over a cavity is characterized by a complex feedback process that leads to large-amplitude, self-sustaining oscillations of the pressure, velocity, and density in and around the cavity. These oscillations are undesirable in a number of engineering applications (e.g., aircraft landing gear and weapons bays) as they can induce structural fatigue and vibration, noise radiation, and drag on bodies possessing the cavity. In light of the strong current interest in active control of cavity oscillations, research focused on improving the understanding and modeling of the cavity flow physics is critical and timely. Research on cavity flowfields during the past 40 years has concentrated primarily on the acoustic environment in and around the cavity. Few investigations have been focused specifically at the cavity shear-layer physics and the mechanisms for noise generation at the cavity trailing edge. Flow-field data are particularly scarce at moderate subsonic Mach numbers. Therefore, detailed measurements of the cavity shear layer, the internal region of the cavity, and the acoustic near field were performed in this dissertation. Cavity length-to-depth ratios of 2 and 4 were considered in these surveys at freestream Mach numbers of 0.25 and 0.4, and 0.6, respectively. Two experimental techniques were used in this investigation: a quantitative schlieren technique known as "optical deflectometry" and hot-wire anemometry (normal and cross wires). The amplitudes and phases of the modal disturbances in the cavity flow field were studied using these high frequency response, high spatial resolution data. The modal disturbances (amplitude and phase components) were extracted from the unsteady flow-field signals using the pressure signal acquired from a transducer embedded in the cavity rear wall and cross-spectral analysis. A secondary objective in this dissertation was to apply joint time-frequency methods and schlieren visualization of the instantaneous cavity shear-layer structure to determine whether "mode switching" occurs between the multiple cavity modes. The detailed flow-field measurements have increased the current understanding of the cavity flow-field physics that cause and maintain the self-sustaining oscillations. Disturbance measurements in the shear layer and internal region of the shallow cavities considered in this study indicate that the wave field is comprised of an upstream-traveling acoustic wave and a downstream-traveling instability wave, both at the same frequency. Disturbance-field measurements in the trailing-edge region of the cavity have provided insight to the nature of the shear-layer/corner interaction. This interaction gives rise to a sound source that provides the feedback necessary to maintain the cavity oscillations. These measurements are expected to aid in the development of theories concerning the sound source and future design of control systems for the suppression of self-sustaining oscillations.

  19. Numerical and experimental investigation of the 3D free surface flow in a model Pelton turbine

    International Nuclear Information System (INIS)

    This investigation focuses on the numerical and experimental analysis of the 3D free surface flow in a Pelton turbine. In particular, two typical flow conditions occurring in a full scale Pelton turbine - a configuration with a straight inlet as well as a configuration with a 90 degree elbow upstream of the nozzle - are considered. Thereby, the effect of secondary flow due to the 90 degree bending of the upstream pipe on the characteristics of the jet is explored. The hybrid flow field consists of pure liquid flow within the conduit and free surface two component flow of the liquid jet emerging out of the nozzle into air. The numerical results are validated against experimental investigations performed in the laboratory of the Institute of Fluid Mechanics (FLM). For the numerical simulation of the flow the in-house unstructured fully parallelized finite volume solver solver3D is utilized. An advanced interface capturing model based on the classic Volume of Fluid method is applied. In order to ensure sharp interface resolution an additional convection term is added to the transport equation of the volume fraction. A collocated variable arrangement is used and the set of non-linear equations, containing fluid conservation equations and model equations for turbulence and volume fraction, are solved in a segregated manner. For pressure-velocity coupling the SIMPLE and PISO algorithms are implemented. Detailed analysis of the observed flow patterns in the jet and of the jeved flow patterns in the jet and of the jet geometry are presented.

  20. Numerical and experimental investigation of the 3D free surface flow in a model Pelton turbine

    Science.gov (United States)

    Fiereder, R.; Riemann, S.; Schilling, R.

    2010-08-01

    This investigation focuses on the numerical and experimental analysis of the 3D free surface flow in a Pelton turbine. In particular, two typical flow conditions occurring in a full scale Pelton turbine - a configuration with a straight inlet as well as a configuration with a 90 degree elbow upstream of the nozzle - are considered. Thereby, the effect of secondary flow due to the 90 degree bending of the upstream pipe on the characteristics of the jet is explored. The hybrid flow field consists of pure liquid flow within the conduit and free surface two component flow of the liquid jet emerging out of the nozzle into air. The numerical results are validated against experimental investigations performed in the laboratory of the Institute of Fluid Mechanics (FLM). For the numerical simulation of the flow the in-house unstructured fully parallelized finite volume solver solver3D is utilized. An advanced interface capturing model based on the classic Volume of Fluid method is applied. In order to ensure sharp interface resolution an additional convection term is added to the transport equation of the volume fraction. A collocated variable arrangement is used and the set of non-linear equations, containing fluid conservation equations and model equations for turbulence and volume fraction, are solved in a segregated manner. For pressure-velocity coupling the SIMPLE and PISO algorithms are implemented. Detailed analysis of the observed flow patterns in the jet and of the jet geometry are presented.

  1. 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.

  2. Silicene: a review of recent experimental and theoretical investigations.

    Science.gov (United States)

    Houssa, M; Dimoulas, A; Molle, A

    2015-06-23

    Silicene is the silicon counterpart of graphene, i.e. it consists in a single layer of Si atoms with a hexagonal arrangement. We present a review of recent theoretical and experimental works on this novel two dimensional material. We discuss first the structural, electronic and vibrational properties of free-standing silicene, as predicted from first-principles calculations. We next review theoretical studies on the interaction of silicene with different substrates. The growth and experimental characterization of silicene on Ag(1?1?1) is next discussed, providing insights into the different phases or atomic arrangements of silicene observed on this metallic surface, as well as on its electronic structure. Recent experimental findings about the likely formation of hexagonal Si nanosheets on MoS2 are also highlighted. PMID:26045468

  3. 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.

  4. 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.

  5. ITER [International Thermonuclear Experimental Reactor] magnet development program at LLNL [Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    The International Thermonuclear Experimental Reactor (ITER) magnet development program at Lawrence Livermore National Laboratory mainly involves developing high-performance, radiation-tolerant magnet concepts. Model coils, full-scale conductors, and insulation systems will be fabricated and tested. This paper briefly describes the program plan. Also included is the description of the Fusion Engineering International Experimental Magnet Facility (FENIX) which is currently under construction for testing full-scale ITER conductors to 40 kA and 14 T. Its design parameters and schedule are reviewed. 2 refs., 2 figs., 1 tab

  6. 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

  7. 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.

  8. 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...

  9. Application of results of experimental identification in control of laboratory helicopter model

    OpenAIRE

    Kamil Dolinsky; Anna Jadlovska

    2011-01-01

    This article deals with experimental identification and control of laboratory helicopter model CE 150 manufactured by company Humusoft. Structure of the identified system was approximated by linear black-box models. Discrete Input/Output Auto-Regressive Moving Average model with eXternal input (ARMAX) and its state space equivalent were used. Parameters of the models were estimated by regression techniques using System Identification Toolbox for Matlab. Acquired models were validated using si...

  10. Current experimental investigations on modern masonry at University of Minho

    OpenAIRE

    Lourenço, Paulo B.; Vasconcelos, Graça; Gouveia, João P.; Haach, V.

    2006-01-01

    The paper presents and describes the main issues related to two systems on modern masonry currently under development at University of Minho, one based on lightweight concrete blocks and another based on reinforced concrete block masonry. The details of the experimental work being carried out are addressed and preliminary test results obtained for lightweight concrete block masonry are provide

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

    Energy Technology Data Exchange (ETDEWEB)

    Green, R.T.; Manteufel, R.D. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Regulatory Applications; Dodge, F.T.; Svedeman, S.J. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

    1993-07-01

    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.

  12. 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

  13. 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.

  14. Experimental and in situ investigations on americium, curium and plutonium behaviour in marine benthic species: transfer from water or sediments

    International Nuclear Information System (INIS)

    The tranfer of transuranic elements -americium, curium and plutonium- from the sediments containing them to some marine benthic species (endofauna and epifauna) was studied with a twofold approach - laboratory and in-situ investigation. The experimental investigations, divided into three parts, made it possible to specify concentration factors (F.C.), transfer factors (F.T.) and to understand the process involved for 5 benthic species. The result were refined by an in-situ study that brought new data on the marine distribution of the transuranic elements released by the La Hague plant. Finally, the localization of americium and plutonium in the tissues and cells of these species was determined by autoradiography

  15. A numerical and experimental investigation of electrothermal aircraft deicing

    Science.gov (United States)

    Leffel, K.; Masiulaniec, K. C.; Dewitt, K. J.; Keith, T. G., Jr.

    1986-01-01

    Experimental data were obtained for the deicing characteristics of a stationary UH-1H helicopter blade which had been fitted with an electrothermal deicer assembly. The tests were run in the NASA Lewis Icing Research Tunnel, and yielded transient temperature responses for the substrate, heater and abrasion shield at selected positions around the blade. The data at the abrasion shield-ice interface clearly documented when melting, shedding or refreezing occurred. Comparisons were made between the experimental data and a one-dimensional numerical model. The agreement was generally very good, with the simulations being shown to be capable of predicting the transient temperature responses along with phase change and ice shedding. At many blade positions, the model was capable of accurately simulating the thermal response of the electrothermal deicer assembly.

  16. 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.

  17. Preliminary experimental investigation of boundary layer in decelerating flow.

    Czech Academy of Sciences Publication Activity Database

    Hladík, Ond?ej; Jonáš, Pavel; P?íhoda, Jaromír

    Liberec : Technical University of Liberec, 2012 - (Vít, T.; Dan?ová, P.; Novotný, P.), s. 249-255 ISBN 978-80-7372-912-7. [Experimental Fluid Mechanics 2012 /7./. Hradec Králové (CZ), 20.11.2012-23.11.2012] R&D Projects: GA ?R GAP101/12/1271; GA ?R GA103/09/0977 Institutional support: RVO:61388998 Keywords : DBD plasma actuator * vorex train * PIV Subject RIV: BK - Fluid Dynamics

  18. 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

    Liberec : Technical university of Liberec, 2014 - (Dan?ová, P.; Vít, T.), s. 712-719 ISSN 2100-014X. - (EPJ Web of Conferences). [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 : transport pipelines * Coulomb friction * coarse-grained mixtures * coarse particle Subject RIV: BK - Fluid Dynamics

  19. 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

  20. Experimental and computational investigations of biomass mixing and combustion processes

    OpenAIRE

    Alganash, B.S.; Paul, M. C.; Watson, I. A.

    2011-01-01

    Biomass is considered to be a promising source of sustainable energy and consequently it is attracting more research attention. The focus of this ongoing study is on the performance of biomass combustion processes. Computational fluid dynamics (CFD) techniques are planned to simulate the combustion process in various models. This is done in parallel with experimental work to understand the mixing and combustion behaviour biomass. For this purpose CFD models based on both Euler-Lag...

  1. 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.

  2. 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

  3. Experimental investigation of the acoustic properties of liquids foams

    OpenAIRE

    Pierre, Juliette; Elias, Florence; Gay, Cyprien; Derec, Caroline; Leroy, Valentin

    2012-01-01

    Liquid foams are mixtures of gas and liquid, with a liquid volume fraction $ \\phi _{l} {\\leq}0.3 $, stabilized with surfactants. Because of their composition and structure, liquid foams are very complex and unstable media with particular acoustical properties. Experimental studies are not very numerous; they have shown a strong dependence of the velocity and attenuation of sound on parameters such as $ \\phi _{l}$ and the average bubble size [1]. The existent theories explain a part of the aco...

  4. Cognitive triggers of auditory hallucinations: an experimental investigation.

    OpenAIRE

    Stinson, K.; Valmaggia, Lr; Antley, A.; Slater, M.; Freeman, D.

    2010-01-01

    It has proved difficult to establish the internal process by which mental events are transformed into auditory hallucinations. The earlier stages of the generation of hallucinations may prove more accessible to research. Cognitions have been reported by patients as a trigger of auditory hallucinations, but the role of these preceding thoughts has not been causally determined. Therefore, the role of cognition in triggering auditory hallucinations was tested in an experimental study. Thirty ind...

  5. Experimental Investigation of Throttling Process Affected by Gas Impurities.

    Czech Academy of Sciences Publication Activity Database

    Vinš, Václav; Vacek, V.

    Liberec : Technical University of Liberec, 2009 - (Vít, T.; Dan?ová, P.; Dvo?ák, V.), s. 411-417 ISBN 978-80-7372-538-9. [International Conference Experimental Fluid Mechanics 2009. Liberec (CZ), 25.11.2009-27.11.2009] Institutional research plan: CEZ:AV0Z20760514 Keywords : capillary tube * experiment * non-condensing gas es * throttling process Subject RIV: BK - Fluid Dynamics

  6. 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 PCO22 (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

  7. 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.

  8. 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.

  9. Experimental investigation on self-leveling behavior in debris beds

    International Nuclear Information System (INIS)

    Research highlights: ? The first application of the depressurization method on self-leveling study. ? Introduce the equivalent power density to evaluate the driving effect. ? The experimental data presented cover a large parameter range. ? Discuss the dependency of self-leveling on various parameters. - Abstract: During a hypothetical core-disruptive accident in a sodium-cooled fast breeder reactor, degraded core materials can form debris beds on the core-support structure and/or in the lower inlet plenum of the reactor vessel from rapid quenching and fragmentation of core material pool. Coolant boiling may lead ultimately to leveling of the debris bed that is crucial to the relocation of molten core and heat-removal capability of the debris bed. In the present study, we elected to use depressurization boiling to simulate an axially increasing void distribution in the debris bed. Bottom-heating boiling was also chosen to confirm that characteristics of the self-leveling process do not depend on the boiling mode. Particle size (between 0.5 and 6 mm), shape (spherical and non-spherical), bed volume (between 5 and 8 l) and density (namely of alumina, zirconia, lead and stainless steel) along with boiling intensity and total volume were taken as experimental parameters to obtain the general characteristics of the self-leveling process. A series of experiments with simulant materials were conducted and analyzed in detail. The good concordance of the transient proceconcordance of the transient processes obtained from the different boiling methods sufficiently demonstrates that the present results obtained using the depressurization boiling method exhibit these general self-leveling characteristics. Detailed comparisons of deduced time variations of the inclination angle provides qualitative tendencies based on the experimental parameters considered influential to self-leveling behavior. The rationale behind the definition introduced for equivalent power density is also presented.

  10. Experimental investigation on self-leveling behavior in debris beds

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Bin, E-mail: b_zhang@nucl.kyushu-u.ac.j [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395 (Japan); Harada, Tetsushi; Hirahara, Daisuke; Matsumoto, Tatsuya; Morita, Koji; Fukuda, Kenji [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395 (Japan); Yamano, Hidemasa; Suzuki, Tohru; Tobita, Yoshiharu [Advanced Nuclear System R and D Directorate, Japan Atomic Energy Agency, 4002 Narita, O-arai, Ibaraki 311-1393 (Japan)

    2011-01-15

    Research highlights: The first application of the depressurization method on self-leveling study. Introduce the equivalent power density to evaluate the driving effect. The experimental data presented cover a large parameter range. Discuss the dependency of self-leveling on various parameters. - Abstract: During a hypothetical core-disruptive accident in a sodium-cooled fast breeder reactor, degraded core materials can form debris beds on the core-support structure and/or in the lower inlet plenum of the reactor vessel from rapid quenching and fragmentation of core material pool. Coolant boiling may lead ultimately to leveling of the debris bed that is crucial to the relocation of molten core and heat-removal capability of the debris bed. In the present study, we elected to use depressurization boiling to simulate an axially increasing void distribution in the debris bed. Bottom-heating boiling was also chosen to confirm that characteristics of the self-leveling process do not depend on the boiling mode. Particle size (between 0.5 and 6 mm), shape (spherical and non-spherical), bed volume (between 5 and 8 l) and density (namely of alumina, zirconia, lead and stainless steel) along with boiling intensity and total volume were taken as experimental parameters to obtain the general characteristics of the self-leveling process. A series of experiments with simulant materials were conducted and analyzed in detail. The good concordance of the transient processes obtained from the different boiling methods sufficiently demonstrates that the present results obtained using the depressurization boiling method exhibit these general self-leveling characteristics. Detailed comparisons of deduced time variations of the inclination angle provides qualitative tendencies based on the experimental parameters considered influential to self-leveling behavior. The rationale behind the definition introduced for equivalent power density is also presented.

  11. Numerical and experimental investigation of thermal louvers for space applications

    Scientific Electronic Library Online (English)

    Issamu, Muraoka; Fabiano Luis de, Sousa; Fernando Manuel, Ramos; Wilson Roberto, Parisotto.

    Full Text Available Thermal louvers, using movable or rotating shutters over a radiating surface, have gained a wide acceptance as highly efficient devices for controlling the temperature of a spacecraft. This paper presents a detailed analysis of the performance of a rectangular thermal louver with movable blades. The [...] radiative capacity of the louver, determined by its effective emittance, is calculated for different values of the blades opening angle. Experimental results obtained with a prototype of a spacecraft thermal louver show good agreement with the theoretical values.

  12. An experimental investigation of the atomic europium anion

    International Nuclear Information System (INIS)

    The electron affinity (EA) of europium has been measured using laser photodetachment electron spectroscopy. The EA of Eu(8S7/2) was determined to be 1.053 ± 0.025 eV. The data also show that Eu- has at least one bound excited state with binding energy of 0.864 ± 0.024 eV relative to the ground state of the europium atom. The experimental results are consistent with recent EA measurements of lanthanide atoms whose anions are predicted to have [Xe](4fn 6p) (where n is odd) configurations

  13. Numerical and experimental investigation of thermal louvers for space applications

    Directory of Open Access Journals (Sweden)

    Muraoka Issamu

    2001-01-01

    Full Text Available Thermal louvers, using movable or rotating shutters over a radiating surface, have gained a wide acceptance as highly efficient devices for controlling the temperature of a spacecraft. This paper presents a detailed analysis of the performance of a rectangular thermal louver with movable blades. The radiative capacity of the louver, determined by its effective emittance, is calculated for different values of the blades opening angle. Experimental results obtained with a prototype of a spacecraft thermal louver show good agreement with the theoretical values.

  14. 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 r...

  15. Investigations of the SAD design parameters for optimum experimental performance

    International Nuclear Information System (INIS)

    A project of fast experimental accelerator driven system called SAD - Subcritical Assembly in Dubna - containing MOX fuel and driven by 660 MeV proton beam is described and analysed. It is shown by design calculations that the necessity exists for certain modifications, allowing for better reliability of measurements of system time characteristics. Different solutions such as: cadmium separation of the biological concrete shield, admixtures of B2O3 to the concrete and certain slowing down of neutrons were analysed. Experiments on a bare spallation targets were conducted and the production of radionuclides in the lead target were measured and compared with calculations

  16. 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.)

  17. 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.)

  18. An experimental investigation of pulse tube refrigeration heat transfer rates

    International Nuclear Information System (INIS)

    Experiments have been performed to show that the heat exchanges between the gas and the walls are more important in the basic pulse tube than in the orifice pulse tube. It is shown that the R/delta ratio well characterizes these heat exchanges. A new concept for describing pulse tube operation is introduced which involves gas-gas heat exchanges. It is shown qualitatively that there must exist heat exchanges elsewhere than in the heat exchangers. An experimental apparatus is described which makes it possible to study these parameters and to obtain good performance. An 85-K temperature limit and a 4-W cold power at 100 K were achieved. 10 refs

  19. Experimental and numerical investigation of flameless pulverised coal combustion

    OpenAIRE

    Stadler, Hannes Alexander

    2010-01-01

    Aim of this work was to investigate the applicability of flameless combustion technology principles to pulverised coal combustion. Lab-scale experiments showed, that it is highly beneficial in terms of NOx reduction to use N2 as coal carrier instead of air. The finding has been supported by OH* chemiluminescence imaging which revealed a suppression of ignition in the coal jet when N2 is used. With the investigated settings, NOx emissions are always above the legislative limit of 200 mg/m3 (st...

  20. Oxides of small Rhodium clusters: Theoretical investigation of experimental reactivities.

    OpenAIRE

    Harding, Dj; Davies, Rd; Mackenzie, Sr; Walsh, Tr

    2008-01-01

    Density functional theory is used to investigate the structures of cationic rhodium cluster oxides, Rh(6)O(m) (+) (m=1,4). On the monoxide and dioxide, the oxygen atoms occupy bridge sites, while on trioxide and tetroxide clusters, high-coordination sites are favored. A range of spin multiplicities are investigated for each cluster, with high spin multiplicities found to be less favored for the oxides compared with the naked metal clusters. The dissociation of nitric oxide on low-energy isome...

  1. Experimental investigation on thermo-magnetic convection inside cavities.

    Science.gov (United States)

    Gontijo, R G; Cunha, F R

    2012-12-01

    This paper presents experimental results on thermo-magnetic convection inside cavities. We examine the flow induced by convective currents inside a cavity with aspect ratio near the unity and the heat transfer rates measurements inside a thin cavity with aspect ratio equal to twelve. The convective unstable currents are formed when a magnetic suspension is subjected to a temperature gradient combined with a gradient of an externally imposed magnetic field. Under these conditions, stratifications in the suspension density and susceptibility are both important effects to the convective motion. We show a comparison between flow patterns of magnetic and gravitational convections. The impact of the presence of a magnetic field on the amount of heat extracted from the system when magnetic and gravitational effects are combined inside the test cell is evaluated. The convection state is largely affected by new instability modes produced by stratification in susceptibility. The experiments reveal that magnetic field enhances the instability in the convective flow leading to a more effective mixing and consequently to a more statistically homogenous temperature distribution inside the test cell. The experimental results allow the validation of the scaling law proposed in a previous theoretical work that has predicted that the Nusselt number scales with the magnetic Rayleigh number to the power of 1/3, in the limit in which magnetic force balances viscous force in the convective flow. PMID:23447978

  2. 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)

  3. Water Sloshing in Rectangular Tanks – An Experimental Investigation & Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Abdennour C Seibi

    2009-05-01

    Full Text Available This paper presents the steps involved in designing a test rig to study water sloshing phenomenon in a 560 x 160 x 185 mm PVC rectangular container subjected to sudden (impulsive impact. The design encompasses the construction of the testing facility and the development of a proper data acquisition system capable of capturing the behavior of pre- and post impact water motion inside the tank. Fluid motion was recorded using a video camera for flow visualization purpose. Two water levels of 50 and 75% full as well as two driving weights of 2.5 and 4.5 kg were used. The experimental study was supplemented by a computational fluid dynamics study to mimic the fluid motion inside the tank. Examination of CFD capability to predict the behavior of the free surface of the fluid during the container initial motion and after impact is the focus of this paper. The flow fields, obtained using the numerical code, are in reasonable agreement with those from experiments. Both experimental and numerical results indicated the presence of a single traveling wave before impact, contrary to what was observed in previous studies.

  4. Experimental Investigation of Large Scale Structures in a Transonic Jet

    Science.gov (United States)

    Ukeiley, Lawrence; Berkooz, Gal; Sherry, James; Glauser, Mark; Seiner, Jack

    1996-11-01

    An experimental effort is underway to study large scale structures and their effect on radiated noise in a transonic jet. In these experiments two rakes of cross-wires will be utilized to measure the velocity field in a Mach 0.85 isothermal jet. The use of two rakes greatly simplifies the necessary probe placements for the calculation of the two-point statistics which will be then analyzed with the Proper Orthogonal Decomposition. A specially designed nozzle will be used for this study, consisting of 12 Kulite pressure sensors offset with 12 glow-discharge devices. Along with studying the streamwise evolution the the large scale structures, the correlation between events in the near field of the jet and the pressure at the lip of the jet will be examined. If this correlation is significant we will be able to build up a correlation matrix for many downstream locations independently and then use a mean square estimation technique to estimate the full flow field at the same instant in time. With the full velocity field at the same instant in time, correlations in the streamwise direction can then be calculated and examined. Initial experimental results along with a detailed description of measurement techniques will be discussed.

  5. Reduction of friction in fluid transport: experimental investigation

    Directory of Open Access Journals (Sweden)

    G. Aguilar

    2006-01-01

    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 más efectiva (es posible obtener reducciones de hasta un factor de 8 en los coeficientes de fricción en segmentos 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 propósitos 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 fluídos no-Newtonianos, reología, y transferencia de calor en la UCSB

  6. An experimental investigation of hollow-cathode-based plasma contactors

    International Nuclear Information System (INIS)

    Experimental results presented describe operation of and the plasma environmental associated with a hollow-cathode-based plasma low-density Maxwellian plasma. A one-dimensional, phenomenological model of the near-field electron-collection process, formulated from experimental observations, is presented. It considers three regions, namely, a plasma cloud adjacent to the contactor, an ambient plasma from which electrons are collected, and a double-layer region that develops between the contractor-plasma cloud and the ambient-plasma regions. Results of electron-emission experiments are also presented. An important observation was made using a retarding potential analyzer (RPA) which showed that high-energy ions generally stream from a contractor along with the electrons being emitted. A mechanism for this phenomenon is presented and it involves a high rate of ionization induced between electrons and atoms flowing together from the hollow cathode orifice. This can result in the development of a region of high positive space charge and, therefore, high positive potential

  7. 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.

  8. Experimental investigation of a cavitating backward-facing step flow

    Science.gov (United States)

    Maurice, G.; Djeridi, H.; Barre, S.

    2014-03-01

    The present study is the first part of global experimental work which is intended to produce a refined database of liquid and vapor phases and to improve CFD modeling of turbulent cavitating flows which can occur in rocket engine turbo-pump inducers. The purpose of the present experimental study is to get a better understanding of the dynamics of the liquid phase in a cavitating backward facing step flow and provide a refined database for the physical analysis of interaction between turbulence and cavitation. The backward facing step flow provides us a well-known test case to compare vortex dynamics and a realistic industrial configuration such as backflow in turbo machinery. Experiments were conducted in the hydrodynamic tunnel of CREMHyG at Grenoble,which was especially designed to study cavitating shear flows at high Reynolds numbers. To highlight the liquid phase topology and dynamics such as large vortex structures, free shear layer instability, reattachment wall interaction and reverse flow, the flow is characterized by Laser Induced Fluoresence Particles Image Velocimetry (PIV-LIF) measurements techniques and by Laser Doppler Velocimetry (LDV) techniques using spectral analysis to characterize the vortex shedding dynamics. The liquid phase was analyzed at different cavitation levels corresponding to 1% to 45% of void ratio range inside the shear layer, recirculation area and reattachment zone. The mean and fluctuating liquid velocities are clearly modified by the vapor phase and the scale of the vortical structures tends to be smaller inducing a destructuration of turbulence by cavitation.

  9. 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.

  10. Experimental and numerical investigation of highly absorbing nonlinear organic chromophores

    Science.gov (United States)

    Parilov, E.; Potasek, M. J.

    2012-02-01

    We have developed a mathematical/numerical framework based on computational transition modules and measured ultrafast laser light propagating through nonlinear materials. The numerical framework can be applied to a broad set of photo-activated materials and lasers, and can optimize photo-physical parameters in multi-photon absorbers. Two photon (TPA) processes are particularly useful in many applications including fluorescence imaging, optical data storage, micro-fabrication, and nanostructured quantum dots for optical limiters. Laser transmission measurements of the organic molecular chromophore, AF455-known TPA material-were taken with a 175 fs, ?0=780nm, plane-polarized light pulses from Ti:S regenerative amplifier into a 5.1mm thick PMMA slab doped with the chromophore. The range of input energies (intensities) in this experiment was 0.01?J (0.97 GW/cm2) to 25 ?J (2.4 x103 GW/cm2). Experiments showed that for intensities beyond several ?J, the material did not saturate as predicted by traditional theory. We included excited-state absorption (ESA), as demonstrated by the absorption spectrum, which still could not account for the deviation. To understand this result we used our framework to show that an unexpected/unknown higher energy level was being populated. We calculated the entire experimental curve from 0.01?J (0.97 GW/cm2) to 25 ?J (2.4 x103 GW/cm2) and found excellent agreement with the experimental data.

  11. 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

  12. Experimental investigation of the reaction at REX-ISOLDE

    CERN Document Server

    Jeppesen, H B; Bergmann, U C; García-Borge, M J; Cederkäll, J; Emhofer, S; Fraile-Prieto, L M; Fynbo, H O U; Henry, S; Johansson, H T; Jonson, B; Meister, M; Nilsson, T; Nyman, G H; Pantea, M; Riisager, K; Richter, A; Rudolph, K; Schrieder, G; Siebert, T; Tengblad, O; Tengborn, E; Turrión, M; Von Hahn, R; Wenander, F; Wolf, B

    2004-01-01

    The particle unbound nucleus $^{10}$Li has been investigated at the newly constructed post-accelerator REX-ISOLDE at CERN via the $^{9}$Li+d to $^{10}$Li+p reaction at 2.36 MeV/u. We present here the preliminary analysis of our first data from REX-ISOLDE.

  13. Experimental Investigations on Drying of Porous Media Using Infrared Radiation

    OpenAIRE

    Haghi, A. K.

    2001-01-01

    Increased interest is being shown in infrared drying today because of the environmental and technological advantages offered by this method. In order to assess the advantages of this drying process, extensive trials have been carried out. The objective of this investigation was to study the drying rate of infrared drying. This was achieved with the use of scanning pyrometer and image analysis. 

  14. 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.

  15. 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%.

  16. 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.

  17. Experimental investigation of a.c. losses in cabled superconductors

    International Nuclear Information System (INIS)

    A.c. losses in multifilamentary composite superconducting strands and cables have been measured in adiabatic conditions for transverse field sweep rates up to 50 T s-1. Measurements were performed on NbTi and Nb3Sn conductors of several configurations and surface preparations: single strands, soldered strands and cables of varying degrees of compaction composed of bare strands, with CuNi barriers and strands with chrome plating. The experimental data agree well with existing loss models. The data suggests that the total cable loss grows as approx.= 1/(void)3 below void fractions of 40%. This observed cable loss dependence on void fraction does not agree well with a previously proposed model. (author)

  18. Experimental investigation on laser milling of PMMA sheet

    Science.gov (United States)

    Genna, S.; Leone, C.; Lopresto, V.; Tagliaferri, V.

    2014-05-01

    In the present paper, laser milling tests were carried out by etching pockets of 10×10 mm2 on the surface of poly-methyl-methacrylate (PMMA) plate, 3 mm in thickness, using a 30 W CO2 laser source, working in continuous or pulsed regime. Aim of the work is to characterize the laser cutting process; or rather, to detect which and how the process parameters affect the depth of machined volume, the removed volume and the surface roughness. The milling tests were carried out changing the released energy, the wave mode (CW or PW), the scan speed, the distance between the linear patterns of two consecutive laser scans (step), the number of repetitions of the geometric pattern. Experimental results have shown that the depth and the machined volume linearly depend on the total amount of released energy. Furthermore, the surface roughness has been evaluated and discussed too.

  19. 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%.

  20. 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.

  1. Molten carbonate fuel cell: dynamic numerical modeling and experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Elisangela Martins [National Institute for Space Research, Cachoeira Paulista, SP (Brazil). Combustion and Propulsion Lab.], e-mail: elisangela@lcp.inpe.br; Jabbari, Faryar [University of California, Irvine, CA (United States). Mechanical and Aerospace Engineering Dept.], e-mail: fjabbari@uci.edu; Brouwer, Jacob [University of California, Irvine, CA (United States). National Fuel Cell Research Center], e-mail: jb@nfcrc.uci.edu

    2006-07-01

    In this paper, a detailed model incorporating simplified geometric resolution of a molten carbonate fuel cell (MCFC) with detailed and dynamic simulation of all physical, chemical, and electrochemical processes in the stream-wise direction is presented. The model was developed using mass and momentum conservation, electrochemical and chemical reaction mechanisms, and heat transfer. Results from the model are compared with data from an experimental MCFC unit. Furthermore, the model was applied to predict dynamic variations of voltage, current and temperature in an MCFC as it responds to varying load demands. The voltage was evaluated by applying a model developed by Yu h and Selman (1991a, 1991b). The results show that the model can be used to predict voltage and dynamic response characteristics of an MCFC accurately and consistently for a variety of temperatures and pressures. (author)

  2. Experimental investigation of damping force of twin tube shock absorber

    Directory of Open Access Journals (Sweden)

    Sandip K. Kadu

    2014-09-01

    Full Text Available A shock absorber is a mechanical device to damp shock impulse and convert kinetic energy into thermal energy. The damping effect of shock absorber depends on damping force and damping force is affected by various process parameters. In this analysis three process parameters damping diameter(A, number of holes(B and suspension velocity(C were considered and their effect on damping force of shock absorber was studied and accordingly suitable orthogonal array was selected by taguchi method. Experiment conducted on servo hydraulic testing machine and after conducting experiments damping force was measured and with the help of S/N ratio, ANOVA, Regression analysis optimum parameter values can be obtained and confirmation experiments was carried out. Twin tube shock absorber was used to carry out experimentation.

  3. 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.

  4. A Experimental Investigation of Double Beta Decay of MOLYBDENUM-100.

    Science.gov (United States)

    Dougherty, Brian Lynn

    New limits on half-lives for several double beta decay modes of ^{100}Mo were obtained with a novel experimental system which included thin source films inter-leaved 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 ^{96}Mo were used to assess remaining backgrounds. With 0.1 mole years of ^{100}Mo data collected, the lower half-life limits at 90% confidence were 2.7 times 10^{18} years for decay via the two-neutrino mode, 5.2 times 10^{19} years for decay with the emission of a Majoron, and 1.6 times 10^{20} years and 2.2 times 10^ {21} years for neutrinoless 0 ^+ to 2^+ and 0^+ to 0^+ transitions, respectively.

  5. 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.

  6. Experimental investigation of different configurations in a flexible heliac

    International Nuclear Information System (INIS)

    The effect of varying the magnetic configuration by adding an l = 1 helical winding to a standard heliac has been studied experimentally. Equilibrium plasma configurations are obtained in the range 0.7 ? ?(0) ? 1.86. Analysis of the plasma pressure profiles measured by Langmuir probes in this range all show good agreement between the plasma isobars and the computed vacuum magnetic surfaces; for configuration with ?(0) close to unity it is necessary to take a known error fields into account. The deterioration of the plasma confinement when low-order rational surfaces are present is clearly observed, and the magnetic islands which result from the resonance between the low-order rational surface ?=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

  7. 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)

  8. 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

  9. 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.

  10. 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.

  11. 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. .

  12. 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.

  13. 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

  14. 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

  15. Experimental buckling investigations of cooling tower shells under wind load

    International Nuclear Information System (INIS)

    The buckling behavior of cooling tower shells under realistic wind loading are investigated. Buckling tests on elastic modells are carried out in a wind-tunnel. As the first step of these tests, the wind-velocity over height and the distribution of the internal and external pressures are measured. After this, the membrane and bending stresses in the shell are measured by means of electrical strain gages and at the same time the critical wind pressure too. Parameters investigated are the wind load and the stiffening by rings, including the effect of the upper edge beam. The effects of the bending moments on the local critical membrane stresses will be determined and the BSS-Approach will be modified. (orig.)

  16. 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.

  17. Experimental investigations of production of glueballs and meson resonant states

    International Nuclear Information System (INIS)

    The major efforts reported have been directed toward investigating glueballs and non-strange mesons. The g/sub T/(2050), g/sub T'/(2300), and g/sub T''/(2350) have been observed in the OZI forbidden reaction ?-p ? phi phi n. Their characteristics are explained within the context of quantum chromodynamics as being produced by 1 to 3 primary glueballs. It is proposed to increase the present statistics in order to reduce the effective partial wave analysis resolution, and to begin to study the high vertical bar t' vertical bar region. It is further planned to pursue coupled channel analysis of high precision ?-p ? K/sub s/0K/sub s/0n data and other relevant world data in the 2++, 0++, and 4++ channels. A program is planned to investigate K-p and p anti p interactions at 8 GeV/c

  18. Experimental investigation of current free double layers in helicon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, B. B. [Department of Applied Sciences and Humanities, Dronacharya College of Engineering, Gurgaon 123506 (India); Tarey, R. D. [Department of Physics, Indian Institute of Technology, New Delhi 110016 (India); Ganguli, A. [Centre for Energy Studies, Indian Institute of Technology, New Delhi 110016 (India)

    2014-02-15

    The paper presents investigations of current free double layer (CFDL) that forms in helicon plasmas. In contrast to the other work reporting on the same subject, in the present investigations the double layer (DL) forms in a mirror-like magnetic field topology. The RF compensated Langmuir probe measurements show multiple DLs, which are in connection with, the abrupt fall of densities along with potential drop of about 24 V and 18 V. The DLs strengths (e??V{sub p})/(k?T{sub e}) are about 9.5 and 6, and the corresponding widths are about 6 and 5 D lengths. The potential drop is nearly equal to the thermal anisotropies between the two plasma regions forming the DL, which is present in the plateau region of mirror, unlike the earlier studies on the DL formation in the region of strong gradients in the magnetic field. Also, it presents a qualitative discussion on the mechanism of DL formation.

  19. Advances with the Chinese anthelminthic drug tribendimidine in clinical trials and laboratory investigations.

    Science.gov (United States)

    Xiao, Shu-Hua; Utzinger, Jürg; Tanner, Marcel; Keiser, Jennifer; Xue, Jian

    2013-05-01

    The anthelminthic drug tribendimidine has been approved by Chinese authorities for human use in 2004, and a first comprehensive review was published in Acta Tropica in 2005. Here, we summarise further advances made through additional clinical trials and laboratory investigations. Two phase IV trials have been conducted in the People's Republic of China, the first one enrolling 1292 adolescents and adults aged 15-70 years and the second one conducted with 899 children aged 4-14 years who were infected with one or multiple species of soil-transmitted helminths. Oral tribendimidine (single 400mg enteric-coated tablet given to adolescents/adults and 200mg to children) showed high cure rates against Ascaris lumbricoides (90.1-95.0%) and moderate-to-high cure rates against hookworm (82.0-88.4%). Another trial done in school-aged children using a rigorous diagnostic approach found a cure rate against hookworm of 76.5%. A single oral dose of tribendimidine showed only low cure rates against Trichuris trichiura (23.9-36.8%) confirming previous results. Tribendimidine administered to children infected with Enterobius vermicularis (two doses of 200mg each on consecutive days) resulted in a high cure rate (97.1%). Importantly, a series of randomised, exploratory trials revealed that tribendimidine shows interesting activity against the liver flukes Opisthorchis viverrini and Clonorchis sinensis, the tapeworm Taenia spp. and the threadworm Strongyloides stercoralis with respective cure rates of 70.0%, 40.0%, 53.3% and 36.4%. Pharmacokinetic studies in healthy Chinese volunteers indicated that after oral administration of tribendimidine, no parent drug was detected in plasma, but its primary metabolite, p-(1-dimethylamino ethylimino) aniline (aminoamidine, deacylated amidantel) (dADT), was found in plasma. dADT is then further metabolised to acetylated dADT (AdADT). dADT exhibits activity against several species of hookworm and C. sinensis in experimental studies, similar to that of tribendimidine. First studies elucidating the mechanism of action suggested that tribendimidine is an L-type nicotinic acetylcholine receptor agonist. Additional experimental studies revealed that the anti-parasite spectrum of tribendimidine is very broad. Indeed, to date, activity has been documented against 20 different nematode, trematode and cestode species. Taken together, tribendimidine warrants further scientific inquiry, including more comprehensive toxicity appraisals, mechanism of action studies and clinical investigation as it holds promise as a broad spectrum anthelminthics. PMID:23352956

  20. 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

  1. Flow in a Pelton Turbine Bucket: Numerical and Experimental Investigations

    OpenAIRE

    Perrig, A.; Avellan, F.; Kueny, J. -l; Parkinson, E.; Farhat, M.

    2006-01-01

    The aim of the paper is to present the results of investigations conducted on the free surface flow in a Pelton turbine model bucket. Unsteady numerical simulations, based on the two-phase homogeneous model, are performed together with wall pressure measurements and flow visualizations. The results obtained allow defining five distinct zones in the bucket from the flow patterns and the pressure signal shapes. The results provided by the numerical simulation are compared for each zone. The flo...

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

    OpenAIRE

    Rasidhar, L.; Ramakrishna, A.; Ch Srinivasa Rao

    2013-01-01

    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 perce...

  3. Experimental Investigation of Turbulent Fluid Flow through a Rectangular Elbow

    OpenAIRE

    Arindam Mandal; Somnath Bhattecharjee; Rabin Debnath; Debasish Roy,; Snehamoy Majumder

    2010-01-01

    The analysis of the turbulent fluid flow in a rectangular elbow is important for many engineering applications like heatexchanger, fluid transport piping system, air conditioning devices etc. Present study investigates the flow visualization of turbulentfluid flow through a rectangular elbow and estimation of co-efficient of friction. The working fluid is air and flow taken to be isincompressible, turbulent and non-reacting. The velocity profiles along the elbow duct are observed at Reynolds ...

  4. Experimental and computational investigation of temperature effects on soot mechanisms

    OpenAIRE

    Bi Xiaojie; Xiao Maoyu; Qiao Xinqi; Lee Chia-Fon F.; Yu Liu

    2014-01-01

    Effects of initial ambient temperatures on combustion and soot emission characteristics of diesel fuel were investigated through experiment conducted in optical constant volume chamber and simulation using phenomenological soot model. There are four difference initial ambient temperatures adopted in our research: 1000 K, 900 K, 800 K and 700 K. In order to obtain a better prediction of soot behavior, phenomenological soot model was revised to take into acco...

  5. Experimental Investigations on Multiphase Phenomena in Porous Media

    OpenAIRE

    Graf, Hans

    2004-01-01

    Modeling of waterflow and solute transport in porous media is typically based on the water dynamics only, while the gaseous phase is neglected. Since the two fluids share the same pore space a particular investigation of the gaseous phase is mandatory to understand its influence on the basic processes (continuity, hysteresis, entrapment,. . . ) especially near water saturation. For the multiphase measurements an existing multistep outflow setup for determination of hydraulic properties with ...

  6. EXPERIMENTAL INVESTIGATIONS OF BEARING CAPACITY FOR ECCENTRICALLY LOADED FOOTING

    Directory of Open Access Journals (Sweden)

    S. M. NAWGHARE

    2010-10-01

    Full Text Available The present work tries to investigate the bearing capacity of eccentrically loaded footing. Footings of different size and shape are used for testing. Testing for bearing capacity of centrally loaded footing and then for eccentrically loaded footing with different ‘e/B’ ratio is carried out. For every footing bearing capacity and settlement has been found out for central as well as eccentric loading. These results of central and eccentric loading are compared with each other for same footing. The results of different footings are also compared for central and eccentric loading. By comparing these results effect of eccentricity, size and shape of footing on bearing capacity has been investigated. In the present study prefabricated model footings and the metal strips are used on the footing for applying eccentric loading. The load has been applied by using hydraulic jack of 20 KN capacity. Two dial gauges are used for measuring settlement, which are arranged diagonally on footing. The results of the previous investigators are also analyzed and compared with the proposed theory. A reasonable agreement was found between the theory and the test data.

  7. Experimental and Modeling Investigation of Shallow Water Table Fluctuations in Relation to Reverse Wieringermeer Effect

    Directory of Open Access Journals (Sweden)

    Ibrahimi Mohamed Khaled

    2011-09-01

    Full Text Available Soil column experiments and modeling investigations were performed to study the behavior of shallow water table in response to various recharge events. Hence, shallow water table fluctuations inside sandy (Toyoura sand and clayey (Chiba light clay soil columns in response to surface and sub-surface recharge events were investigated under laboratory conditions. Experimental results showed that small application of water could raise the shallow water table level more than 100 times in depth in the case of Toyoura sand and more than 50 times in the case of Chiba LiC, reflecting a reverse Wieringermeer effect (RWE response type of groundwater. This rise was associated with a prompt change of pressure head values which exhibited instantaneous fluctuations of centimeters due to the addition of millimeters of water. The recharge volumes leading to such disproportionate water table rise were successfully estimated using a simple analytical model based on the moisture retention curve of the soil and considering the hysteresis effect on soil water dynamics within the capillary fringe zone.

  8. Numerical and Experimental Investigation into Hot Forming of Ultra High Strength Steel Sheet

    Science.gov (United States)

    Liu, Hongsheng; Liu, Wei; Bao, Jun; Xing, Zhongwen; Song, Baoyu; Lei, Chengxi

    2011-02-01

    Hot forming of ultra high strength steel (UHSS) sheet metal grade 22MnB5 boron for channel components using water cooling is studied on a laboratory scale. After hot forming, the different microstructures such as martensite, bainite, and pearlite in formed component are produced, which are closely related with mechanical properties of formed component. The effect of forming start temperature and the contact state between blank and die on the microstructure evolution is investigated. In addition, the effect of processing parameters, such as forming start temperature and blank holder force (BHF), on the final quality of component, i.e., springback, that happens after hot forming of UHSS is investigated. It can be concluded that the forming start temperature has a significant effect on the final mechanical properties of formed components. The effect of forming start temperature on springback is examined in detail under a wide range of operating conditions. The higher the BHF and the forming start temperature, the lower is the springback after hot forming. Furthermore, thermo-mechanically coupled finite element analysis model encompassing heating of sheet blank, forming and quenching are developed for hot forming process. The stress distributions on sheet blank under different conditions during hot forming are compared to gain a fundamental understanding of the mechanism of springback. Comparisons show that numerical simulation results have good agreement with experimental results.

  9. 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. Thistion 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.)

  10. Experimental investigation of zero phase shift effects for Coriolis flowmeters due to pipe imperfections

    DEFF Research Database (Denmark)

    Enz, Stephanie; Thomsen, Jon Juel

    2011-01-01

    Theoretical investigations of a single, straight, vibrating, fluid-conveying pipe have resulted in simple analytical expressions for the approximate prediction of the spatial shift in vibration phase. The expressions have lead to hypotheses for real Coriolis flowmeters (CFMs). To test these, the flexural vibrations of two bent, parallel, non-fluid-conveying pipes are studied experimentally, employing an industrial CFM. Special attention has been paid on the phase shift in the case of zero mass flow, i.e. the zero shift, caused by various imperfections to the ‘‘perfect’’ CFM, i.e. non-uniform pipe damping and mass, and on ambient temperature changes. Experimental observations confirm the hypothesis that asymmetry in the axial distribution of damping will induce zero shifts similar to the phase shifts due to fluid flow. Axially symmetrically distributed damping was observed to influence phase shift at an order of magnitude smaller than the primary effect of mass flow, while small added mass and ambient temperature changes induced zero shifts two orders of magnitude smaller than the phase shifts due to mass flow. The order of magnitude of the induced zero shifts indicates that non-uniform damping, added mass as well as temperature changes could be causes contributing to a time-varying measured zero shift, as observed with some commercial CFMs. The conducted experimental tests of the theoretically based hypotheses have shown that simple mathematical models and approximate analysis allow general conclusions, that may provide a direct insight, and help increasing the benefit of time consuming numerical simulations and laboratory experiments.

  11. EXPERIMENTAL INVESTIGATION OF RELATIVE PERMEABILITY UPSCALING FROM THE MICRO-SCALE TO THE MACRO-SCALE

    Energy Technology Data Exchange (ETDEWEB)

    Laura J. Pyrak-Nolte; Nicholas J. Giordano; David D. Nolte

    2004-03-01

    The principal challenge of upscaling techniques for multi-phase fluid dynamics in porous media is to determine which properties on the micro-scale can be used to predict macroscopic flow and spatial distribution of phases at core- and field-scales. The most notable outcome of recent theories is the identification of interfacial areas per volume for multiple phases as a fundamental parameter that determines much of the multi-phase properties of the porous medium. A formal program of experimental research was begun to directly test upscaling theories in fluid flow through porous media by comparing measurements of relative permeability and capillary-saturation with measurements of interfacial area per volume. This project on the experimental investigation of relative permeability upscaling has produced a unique combination of three quite different technical approaches to the upscaling problem of obtaining pore-related microscopic properties and using them to predict macroscopic behavior. Several important ''firsts'' have been achieved during the course of the project. (1) Optical coherence imaging, a laser-based ranging and imaging technique, has produced the first images of grain and pore structure up to 1 mm beneath the surface of the sandstone and in a laboratory borehole. (2) Woods metal injection has connected for the first time microscopic pore-scale geometric measurements with macroscopic saturation in real sandstone cores. (3) The micro-model technique has produced the first invertible relationship between saturation and capillary pressure--showing that interfacial area per volume (IAV) provides the linking parameter. IAV is a key element in upscaling theories, so this experimental finding may represent the most important result of this project, with wide ramifications for predictions of fluid behavior in porous media.

  12. Experimental investigation of ion-ion recombination at 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.; 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.

    2015-02-01

    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 (?+) 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.

  13. Report of investigation into allegations of retaliation for raising safety and quality of work issues regarding Argonne National Laboratory's Integral Fast Reactor project

    International Nuclear Information System (INIS)

    In August 1990 James A. Smith resigned his position as an experimenter at Argonne National Laboratory-West (ANL-W), located near Idaho Falls, Idaho. Smith who holds a Ph.D. in metallurgy, had worked at the Laboratory since 1988, primarily on its Integral Fast Reactor (IFR) project. He alleged that the quality of the Laboratory's work on that project had been undermined by fundamental errors in metallurgy and related sciences, at least some of which had nuclear safety implications; that the Laboratory had published false and misleading accounts of its work; that prevailing attitudes at the Laboratory were antithetical to quality scientific work; and that because he had expressed concerns about these matters his job was threatened by his managers. Evidence gathered during an investigation by the Department of Energy's Office of Nuclear Safety (NS) is presented and conclusions and recommendations are provided

  14. Simulant-material experimental investigation of flow dynamics in the CRBR Upper-Core Structure

    International Nuclear Information System (INIS)

    The results of a simulant-material experimental investigation of flow dynamics in the Clinch River Breeder Reactor (CRBR) Upper Core Structure are described. The methodology used to design the experimental apparatus and select test conditions is detailed. Numerous comparisons between experimental data and SIMMER-II Code calculations are presented with both advantages and limitations of the SIMMER modeling features identified

  15. Experimental investigation of condensation predictions for dust-enriched systems

    Science.gov (United States)

    Ustunisik, Gokce; Ebel, Denton S.; Walker, David; Boesenberg, Joseph S.

    2014-10-01

    Condensation models describe the equilibrium distribution of elements between coexisting phases (mineral solid solutions, silicate liquid, and vapor) in a closed chemical system, where the vapor phase is always present, using equations of state of the phases involved at a fixed total pressure (bar) and temperature (T). The VAPORS code uses a CaO-MgO-Al2O3-SiO2 (CMAS) liquid model at T above the stability field of olivine, and the MELTS thermodynamics algorithm at lower T. Quenched high-T crystal + liquid assemblages are preserved in meteorites as Type B Ca-, Al-rich inclusions (CAIs), and olivine-rich ferromagnesian chondrules. Experimental tests of compositional regions within 100 K of the predicted T of olivine stability may clarify the nature of the phases present, the phase boundaries, and the partition of trace elements among these phases. Twenty-three Pt-loop equilibrium experiments in seven phase fields on twelve bulk compositions at specific T and dust enrichment factors tested the predicted stability fields of forsteritic olivine (Mg2SiO4), enstatite (MgSiO3), Cr-bearing spinel (MgAl2O4), perovskite (CaTiO3), melilite (Ca2Al2SiO7-Ca2Mg2Si2O7) and/or grossite (CaAl4O7) crystallizing from liquid. Experimental results for forsterite, enstatite, and grossite are in very good agreement with predictions, both in chemistry and phase abundances. On the other hand the stability of spinel with olivine, and stability of perovskite and gehlenite are quite different from predictions. Perovskite is absent in all experiments. Even at low oxygen fugacity (IW-3.4), the most TiO2-rich experiments do not crystallize Al-, Ti-bearing calcic pyroxene. The stability of spinel and olivine together is limited to a smaller phase field than is predicted. The melilite stability field is much larger than predicted, indicating a deficiency of current liquid or melilite activity models. In that respect, these experiments contribute to improving the data for calibrating thermodynamic models including MELTS.

  16. 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)

  17. 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.

  18. Experimental and Numerical Investigation of the Dynamic Seat Comfort in Aircrafts

    Science.gov (United States)

    Ciloglu, Hakan

    This research focuses on the dynamic seat comfort in aircrafts specifically during takeoff, landing and cruise through turbulence flight conditions. The experiments are performed using a multi axis shaker table in the Automotive Centre of Excellence (ACE) at the University of Ontario Institute of Technology subjected to sample takeoff, landing and cruise vibration recordings obtained onboard of an actual flight. The input vibrations introduced to the aircraft seats during actual flight conditions and during the experiments in the ACE are compared and it is concluded that the given flight conditions were successfully replicated for the interest of this thesis. The experiments are conducted with two different aircraft seats, economy class and business class. Furthermore, to investigate the importance of seat cushion characteristics in addition to economy and business class seat cushions, three laboratory made cushions were included in the investigation as well. Moreover, the effect of passenger weight is also discussed by conducting the experiments with 1 and 2 identical dummies. It is concluded that static seat properties play a significant role in the comfort perception level as well as flight conditions. Among the three flight condition, landing appeared to be the most uncomfortable case comparing to takeoff and cruise. In addition to experimental work, a numerical study to simulate the flight conditions is undertaken with the initial work of CAD modelling. The simulated responses of the seat is partially matching with experimental results due to unknown parameters of the cushion and the connections of the aircraft seat that cannot be created in the CAD model due to unknown manufacturing processes.

  19. On the upper part load vortex rope in Francis turbine: Experimental investigation

    International Nuclear Information System (INIS)

    The swirling flow developing in Francis turbine draft tube under part load operation leads to pressure fluctuations usually in the range of 0.2 to 0.4 times the runner rotational frequency resulting from the so-called vortex breakdown. For low cavitation number, the flow features a cavitation vortex rope animated with precession motion. Under given conditions, these pressure fluctuations may lead to undesirable pressure fluctuations in the entire hydraulic system and also produce active power oscillations. For the upper part load range, between 0.7 and 0.85 times the best efficiency discharge, pressure fluctuations may appear in a higher frequency range of 2 to 4 times the runner rotational speed and feature modulations with vortex rope precession. It has been pointed out that for this particular operating point, the vortex rope features elliptical cross section and is animated of a self-rotation. This paper presents an experimental investigation focusing on this peculiar phenomenon, defined as the upper part load vortex rope. The experimental investigation is carried out on a high specific speed Francis turbine scale model installed on a test rig of the EPFL Laboratory for Hydraulic Machines. The selected operating point corresponds to a discharge of 0.83 times the best efficiency discharge. Observations of the cavitation vortex carried out with high speed camera have been recorded and synchronized with pressure fluctuations measurements at the draft tube cone. Firstmeasurements at the draft tube cone. First, the vortex rope self rotation frequency is evidenced and the related frequency is deduced. Then, the influence of the sigma cavitation number on vortex rope shape and pressure fluctuations is presented. The waterfall diagram of the pressure fluctuations evidences resonance effects with the hydraulic circuit. The time evolution of the vortex rope volume is compared with pressure fluctuations time evolution using image processing. Finally, the influence of the Froude number on the vortex rope shape and the associated pressure fluctuations is analyzed by varying the rotational speed.

  20. 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.

  1. Experimental investigation of muon induced deuterium-tritium fusion

    International Nuclear Information System (INIS)

    There has been growing interest in muon catalyzed d/t-fusion. Due to the recent discovery of a resonance in the d?t formation process numerous fusions can be catalyzed in d/t mixtures at 'cold' temperatures (30K-1000K) compared to conventional plasma fusion devices. The authors are particularly interested in this remarkable resonant molecular formation mechanism. The current investigation of the complicated d/t-system aims to clarify all the basic processes involved in muon catalyzed fusion. (Auth.)

  2. Experimental investigation of radionuclide transport in the Arctic Ocean

    International Nuclear Information System (INIS)

    The project task is to investigate and quantify the transport of radioactively contaminated sediments from Novaya Zemlya and the Kara Sea to other arctic regions by the transport medium 'Arctic Ocean ice'. It is expected that transport of radioactive environmental materials through the ice masses forming in this region plays a more important role than transport through sea currents, which would involve dilution of dissolved radionuclide concentrations. Also, transport by the ice masses is much faster than water-borne transport, so that the radioactivity could be released much earlier in the area east of Greenland. (orig./CB)

  3. Experimental plant for investigation of the possibility of production of medicine intended isotopes on the basis of linear accelerator

    International Nuclear Information System (INIS)

    A method of 99mTc production by irradiation of molybdenum using high-intensity Bremsstrahlung photons from the electron beam of linear electron accelerator LUE50 of the A.I.Alikhanian National Science Laboratory (former Yerevan Physics Institute) is described. The experimental layout for 99mTc production technology development has been designed and constructed. An upgrade of the linear electron accelerator was carried out to increase the electron beam intensity and spatial density. A system of computer-based remote control of the accelerator and experimental layout has been built up. Preliminary experimental investigations of 99mTc production methods have been preformed and the qualitative and quantitative results of these studies are presented

  4. Experimental investigation of a.c. losses in cabled superconductors

    Science.gov (United States)

    Mower, T. M.; Iwasa, Y.

    A.c. losses in multifilamentary composite superconducting strands and cables have been measured in adiabatic conditions for transverse field sweep rates up to 50 T s -1. Measurements were performed on NbTi and Nb 3Sn conductors of several configurations and surface preparations: single strands, soldered strands and cables of varying degrees of compaction composed of bare strands, strands with CuNi barriers and strands with chrome plating. The experimental data agree well with existing loss models. Loss data are characterized in terms of effective coupling current time constants. It has been determined that chrome plating on strands can reduce the coupling loss in highly compacted cables to as little as 20% of the coupling loss in similar cables composed of bare strands. In loosely compacted cables (down to ? 50% void) the strand-to-strand coupling loss was less than the filament coupling loss. As compaction is increased below 50% void the strand coupling quickly increases and becomes the dominant loss mechanism. The data suggest that the total cable loss grows as ? 1/(void) 3 below void fractions of 40%. This observed cable loss dependence on void fraction does not agree well with a previously proposed model.

  5. Experimental investigation and prediction of oiling out during crystallization process

    Science.gov (United States)

    Kiesow, Kai; Tumakaka, Feelly; Sadowski, Gabriele

    2008-08-01

    Oiling out is an unwanted effect during the cooling crystallization of complex molecules from solution: upon cooling, crystallization is preceded by the formation of a second liquid phase (oiling out) which disturbs the crystallization process and often deteriorates the product properties. On the basis of the crystallization of 4,4' dihydroxydiphenylsulfone (DHDPS) from water/acetone mixtures and water/2-propanol mixtures, respectively, this study proved the dependence of the oiling-out behavior on the solvent system. Attempts were made to model the oiling-out phenomenon using a thermodynamic equation of state here: (Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT)). Applying this model, an oiling-out behavior of the ternary system DHDPS/water/acetone could be predicted qualitatively. Exchanging the water/acetone solvent mixture by a mixture of water and 2-propanol led to a prevention of oiling out. This could be predicted by the calculations using PC-SAFT, as well as confirmed experimentally. Furthermore, micrographs of the crystals obtained revealed the influence of the oiling out on the properties of the solid product. Size, shape and degree of agglomeration of the particles vary depending on whether an oiling out occurred during the cooling process or not.

  6. Numerical and experimental investigations into Tailored Welded Blanks formability

    International Nuclear Information System (INIS)

    A Tailor welded blank (TWB) technology gives automotive designers the ability to selectively vary body panel thickness and alloy to optimize the use of material. TWBs offer several notable benefits including decreased part weight, reduced manufacturing costs, increased environmental friendliness, and improved dimensional consistency. In order to take advantage of these benefits, however, designers need to overcome the formability of TWBs and be able to accurately predict unique characteristics related to TWB forming early in the design process. In this paper, a numerical model to predict the forming height dome and a specific forming curve of TWBs is presented. Finite element analyses of standard TWB forming tests (Nakazima) were performed in Arcelor Mittal Auto Application Research Center to determine the interaction between the weaker and the stronger materials. To measure the critical strain at necking a numerical method is used. A comparison of numerical and experimental results highlights a good agreement. The numerical approach offers a considerable gain to obtain specific FLC for all configurations

  7. Experimental investigation of sodium bentonite stability in Hanford basalt

    International Nuclear Information System (INIS)

    Sodium bentonite is a candidate material for the waste package backfill component in a repository in basalt at the Hanford Site. Preliminary hydrothermal experiments have been conducted under near-field geochemical conditions expected to occur in the reference repository location in Grande Ronde Basalt. Experiments have been conducted in the basalt/groundwater, bentonite/groundwater, and basalt/bentonite/groundwater systems. The experiments have been conducted at 3000C using a simulated Grande Ronde groundwater, reference Umtanum basalt, and sodium bentonite. Key data generated by the experiments include experimental solution analyses as a function of time and preliminary solids analysis by scanning transmission electron microscopy and x-ray diffraction. Solution trends of the major aqueous species were similar in the three systems and are characterized by: (1) the gradual reduction of the pH value from approx.9.75 to a steady-state value of approx.6, (2) an initial rapid increase followed by a gradual decreasein silica concentration, and (3) a slight or negligible increase in sodium, sulfate, and chloride concentrations. In the bentonite/groundwater experiment, small amounts (0C under hydrothermal conditions in basalt>C under hydrothermal conditions in basalt to permit its use as a backfill material

  8. 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.

  9. 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.

  10. Spectroscopic investigation of PF-1000 discharges under different experimental conditions

    International Nuclear Information System (INIS)

    The emission from free-propagating plasma streams was studied in experiments with a 1-MJ plasma-focus PF-1000 facility operated at the IPPLM in Warsaw, Poland. The machine was filled up with a pure deuterium or a mixture of deuterium and argon. Optical spectra were recorded at a distance of 30 cm from the electrodes, at different experimental conditions, i.e. initial pressures, charging voltages and acquisition times, in the wavelength range of 350...1000 nm. The most intense lines originated from the applied working gases. In some cases distinct CuI and FeI lines resulted from the electrodes and the insulator were observed. From the Balmer lines, D? and D?, an electron density as a function of time was estimated. The application of this finding made it possible to perform some experiments concerning spectroscopic research on the interaction of free-propagating plasma streams with tungsten targets. In the recorded spectra some WI and WII lines were identified, but the resolution of the spectrometer was not good enough for their quantitative analysis.

  11. Experimental investigation of posterior elbow dislocation in a primate model.

    Science.gov (United States)

    Abraham, E; Alkork, S; Amirouche, F; Hande, E; Pratap Rai, S; Biafora, S

    2007-01-01

    The purpose of this experimental study was to define the soft and bony tissues changes as the elbow joint dislocates posteriorly in a primate model. Sixty-six fresh arms were used in this study and were divided into two groups where manual and automated procedures were performed to address the mechanism of elbow dislocation. The first group called IA (50 arms) was tested using a special designed apparatus and was used for Instron machine whereas second group IB (16 arms) a manual dislocation by hyper-extending the elbow at the end of the tabletop was performed. An axial compressive load was applied on the distal forearm at a constant rate of 10 mm/min in group IA. The humerus was rigidly secured on a humeral plate at 90 degrees (3), 45 degrees (17), 30 degrees (13) and 0 degrees (17) of elbow flexion. Photographs and computer data recorded the changes in the soft tissue and bone at the elbow. It required on average 1960 N to dislocate the elbow in pronation with flexion (45, 30 degrees) compared to 1030 N for supination and the elbow flexion (45, 30 degrees). Three reproducible stages of dislocation from initiation to complete failure were observed when the elbow was flexed at 45 degrees or 30 degrees with forearm pronated or supinated. PMID:18003153

  12. Experimental Investigation of Drilling Fluid Performance as Nanoparticles

    Directory of Open Access Journals (Sweden)

    Jamal Nasser

    2013-09-01

    Full Text Available In this work, a drilling fluid recipe has been developed by using nanoparticles, to increase the efficiency of drilling operations for maximum accessibility to new & matured oil reserves and suited to various drilling conditions. The solution to severe drilling problems like pipe sticking, lost circulation, formation damage, erosion of borehole, thermal instability of drilling fluids and insufficient gel properties of the drilling fluids, lies in controlling and optimizing the rheology of the drilling fluid. The inefficiency of the drilling fluid in performing certain functions is mainly due to a lack in a particular rheological property. The performance of the clay composites water-based bentonite drilling mud in terms of its rheological behavior in drilling systems was investigated at various pressures and temperatures. It was found that temperature had a detrimental effect on the rheological properties. The behavior was investigated using synthesized nano bentonite water based drilling fluid. The fluid retained all the desired rheological properties at elevated temperatures and pressures, thus enhanced the possibility of its application in deep wells, where elevated temperatures and pressures were quite common.

  13. 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 sand-gravel material, the storage media is to be water satured. In this case, handling of such material on site is rather complex. The conduction is highly dependent on the thermal properties of the storage media and so is the overall thermal performance of a storage applying such media. For sandy 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 about the expected behaviour of large storage systems.

  14. Colloid-Facilitated Transport of Low-Solubility Radionuclides: A Field, Experimental, and Modeling Investigation

    Energy Technology Data Exchange (ETDEWEB)

    Kersting, A B; Reimus, P W; Abdel-Fattah, A; Allen, P G; Anghel, I; Benedict, F C; Esser, B K; Lu, N; Kung, K S; Nelson, J; Neu, M P; Reilly, S D; Smith, D K; Sylwester, E R; Wang, L; Ware, S D; Warren, RG; Williams, R W; Zavarin, M; Zhao, P

    2003-02-01

    For the last several years, the Underground Test Area (UGTA) program has funded a series of studies carried out by scientists to investigate the role of colloids in facilitating the transport of low-solubility radionuclides in groundwater, specifically plutonium (Pu). Although the studies were carried out independently, the overarching goals of these studies has been to determine if colloids in groundwater at the NTS can and will transport low-solubility radionuclides such as Pu, define the geochemical mechanisms under which this may or may not occur, determine the hydrologic parameters that may or may not enhance transport through fractures and provide recommendations for incorporating this information into future modeling efforts. The initial motivation for this work came from the observation in 1997 and 1998 by scientists from Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL) that low levels of Pu originally from the Benham underground nuclear test were detected in groundwater from two different aquifers collected from wells 1.3 km downgradient (Kersting et al., 1999). Greater than 90% of the Pu and other radionuclides were associated with the naturally occurring colloidal fraction (< 1 micron particles) in the groundwater. The colloids consisted mainly of zeolite (mordenite, clinoptilolite/heulandite), clays (illite, smectite) and cristobalite (SiO{sub 2}). These minerals were also identified as alteration mineral components in the host rock aquifer, a rhyolitic tuff. The observation that Pu can and has migrated in the subsurface at the NTS has forced a rethinking of our basic assumptions regarding the mechanical and geochemical transport pathways of low-solubility radionuclides. If colloid-facilitated transport is the primary mechanism for transporting low-solubility radionuclides in the subsurface, then current transport models based solely on solubility arguments and retardation estimates may underestimate the flux and rate of Pu transport. Currently, the role of colloids in facilitating the transport of low-solubility radionuclides is not understood well enough to effectively model contaminant transport. A fundamental understanding of the role that colloids may or may not play in the transport of low-solubility radionuclides is needed in order to predict contaminant transport, design remediation strategies and provide risk assessments. Ryan and Elimelech (1996) have argued that in order to evaluate the potential for colloids to transport radionuclides, several criteria must be met: (1) colloids must exist and be stable, (2) radionuclides must have a high sorption affinity for the colloids, and (3) colloids must be transported. Only then can we understand the conditions where colloids can and will facilitate transport of radionuclides. In this report we compile the results from a series of field, laboratory and modeling studies funded by the UGTA program in order to evaluate the potential for colloids to transport low-solubility radionuclides at the NTS. The studies presented in this report fall under three general areas of investigation: Characterization of natural colloids in groundwater at NTS, Pu sorption/desorption experiments on colloid minerals identified in NTS groundwater, and Transport of Pu-doped colloids through fractured rock core. Chapter 1 is a background review of our current understanding of colloids and their role in facilitating contaminant transport. Chapters 2, and 3 are field studies that focused on characterizing natural colloids at different hydrologic environments at the NTS and address Ryan and Elimelech's (1996) first criteria regarding the existence and stability of colloids. Chapters 4, 5 and 6 are laboratory experimental studies that investigate the sorption/desorption behavior of Pu and other low-solubility radionuclides on colloid minerals observed in NTS groundwater. These studies evaluate Ryan and Elimelech's (1996) second criteria that the affinity of Pu for colloids must be high. Chapters 7, 8, 9, and 10 are laboratory studies t

  15. An Experimental and Computational Investigation of Gas/Particle Flow in a Vertical Lifter

    OpenAIRE

    Mathisen, Anette

    2010-01-01

    Experimental and computational investigations of dilute gas/particle flow in a vertical lifter are performed. The effect of superficial gas velocity, particle density, particle size distribution and particle loading on particle velocities, particle fluctuations and particle cross-moment have been studied experimentally using laser Doppler anemometry (LDA) and particle image velocimetry (PIV). The results from the experimental investigation is compared with the computational investigatio...

  16. The experimental and numerical investigation of a grooved vapor chamber

    International Nuclear Information System (INIS)

    An effective thermal spreader can achieve more uniform heat flux distribution and thus enhance heat dissipation of heat sinks. Vapor chamber is one of highly effective thermal spreaders. In this paper, a novel grooved vapor chamber was designed. The grooved structure of the vapor chamber can improve its axial and radial heat transfer and also can form the capillary loop between condensation and evaporation surfaces. The effect of heat flux, filling amount and gravity to the performance of this vapor chamber is studied by experiment. From experiment, we also obtained the best filling amount of this grooved vapor chamber. By comparing the thermal resistance of a solid copper plate with that of the vapor chamber, it is suggested that the critical heat flux condition should be maintained to use vapor chamber as efficient thermal spreaders for electronics cooling. A two-dimensional heat and mass transfer model for the grooved vapor chamber is developed. The numerical simulation results show the thickness distribution of liquid film in the grooves is not uniform. The temperature and velocity field in vapor chamber are obtained. The thickness of the liquid film in groove is mainly influenced by pressure of vapor and liquid beside liquid-vapor interface. The thin liquid film in heat source region can enhance the performance of vapor chamber, but if the starting point of liquid film is backward beyond the heat source region, the vapor chamber will dry out easily. The optimal fchamber will dry out easily. The optimal filling ratio should maintain steady thin liquid film in heat source region of vapor chamber. The vapor condenses on whole condensation surface, so that the condensation surface achieves great uniform temperature distribution. By comparing the experimental results with numerical simulation results, the reliability of the numerical model can be verified

  17. Inversion and Experimental Methods for Tomographic Investigations in Hydrogeology

    Science.gov (United States)

    Leven, C.; Schwede, R. L.; Doro, K. O.; Sanchez-Leon, E. E.; Cirpka, O. A.

    2014-12-01

    The spatial variability of hydraulic conductivity K highly influences flow and solute transport in the subsurface. The estimation of the spatial distribution of K in heterogeneous aquifers with an adequate resolution and support scale is therefore one of the major challenges in hydrogeology and still seems to be unsolved. Even though direct measurements of K with modern methods reveal the distribution with typically high vertical resolutions, they still are scarce and local. Therefore, K is mostly inferred from measurements of quantities depending on K, such as hydraulic heads monitored during hydraulic tests and tracer test data. Conventional approaches, such as the type-curve approach for pumping tests, fail in estimating the spatial distribution of K, since they are based on the assumption of homogeneity. Even if data from multi-well pumping tests are analyzed, they always will yield different effective parameters. In contrast, tomographic techniques originally derived for geophysical surveying can be transferred to hydraulic applications and are much better suitable to derive K distributions. In this presentation, we will show results of the project "Tomographic Methods in Hydrogeology" in which we focused on the development of geostatistical methods for the inversion of tomographic data sets of different types (hydraulic testing, heat and ERT-monitoring of salt tracer tests) and the development and improvement of such experimental techniques. Based on selected examples we will present our developments related to the joint geostatistical inversion of tomographic data sets, its efficient parallelization, and its application to a 3D-inversion of tomographic thermal tracer tests. Related to the acquisition of tomographic data sets, we discuss different aspects of the field application of hydraulic tomography, the development of tracer-tomographic methods using heat as tracer, and efficient salt-tracer techniques with a ERT-based salt-tracer monitoring.

  18. Experimental and computational investigation of inclined jets in a crossflow

    Science.gov (United States)

    Findlay, Matthew James

    1998-11-01

    The flow field characteristics of four different geometries of a row of square jets in a crossflow at velocity ratios relevant to gas turbine film cooling applications have been examined using experimental and computational methods. The geometries considered were: long and short entry length streamwise-inclined jets, spanwise-inclined jets, and compound-angle jets. Mean velocity and turbulence measurements were made using a three-component LDV system. Jet penetration, spreading, and film cooling effectiveness were measured using a flame ionization detector. Numerical simulations were performed using three different turbulence models: the standard k-/epsilon model, Menter's baseline blended k-/epsilon/k-/omega model, and Menter's shear stress transport model. The flow field at the jet exit is strongly influenced by the crossflow, as well as by the inlet conditions at the entrance to the jet orifice. At low velocity ratios the jets do not penetrate beyond the upstream boundary layer thickness. As the velocity ratio increases, the jet penetrates beyond the boundary layer resulting in stronger interaction with the crossflow. Considerable anisotropy of the turbulent flow field is observed. The film cooling effectiveness is best at the lowest velocity ratio as the jet is deflected strongly towards the floor of the wind tunnel, although the improvement is more significant for the streamwise injection case. At the highest velocity ratio the spanwise jets provide the best film cooling effectiveness but provide increased blockage to the crossflow. The results of the preliminary computational analysis indicate that the flow field produced by each of the geometries provides a serious challenge for numerical modelling. Mean velocity gradients and turbulence kinetic energy levels are typically underpredicted by the computations due to the assumption of equilibrium turbulence inherent in the models. The use of an isotropic eddy viscosity model must be reconsidered in light of the measured turbulence anisotropy and generation of turbulent shear stresses from velocity gradients not included in the standard eddy viscosity formulation.

  19. 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.

  20. Experimental Investigation of Decollement Zone Mechanics and Consolidation State

    Science.gov (United States)

    Ralser, S.; Tobin, H. J.

    2001-12-01

    Studies on accretionary prism decollement fault zones show them to be very weak structures, with pore pressures close to the lithostatic overburden stress. We have designed a series of experiments to address whether high strains and retained high porosity can coexist in such decollement zones. The experiments will also document the stress paths to obtain these conditions, as well as the microstructures that are developed. We are deforming artificial analogs of decollement lithologies (35% silt sized quartz, 50% montmorillonite, 15% kaolinite) in a high-pressure ring shear device mounted on an MTS torsion-testing device. Experiments were conducted with a normal stress of 9 MPa, a shear strain rate of ca. 7 x 10-4s-1 to a shear strain of ca. 40 (360\\deg rotation in 16 days). Fluid pressures of 7 MPa and 8.8 MPa were used. Experiments were conducted on samples which were normally consolidated and overconsolidated (compacted and then subject to a decrease in effective stress). Experimental conditions, are such, that they simulate in situ conditions from currently sampled decollement zones (e.g. Barbados and Nankai). A normally consolidated sample shows a shear stress of ca. 2.5 MPa (normal stress - 9 MPa, fluid pressure 7 MPa, normally consolidated); the overconsolidated samples are expected to be stronger and the samples with a higher fluid pressure are expected to be weaker. We are also able to measure fault-parallel and fault-perpendicular P and S wave seismic velocity. These results will allow comparison with seismic observations. Preliminary results indicate a reduction of Vp and Vs on the order of 5-8% with the reduction occurring with a shear stress of less than 15. The results of these experiments will allow us to explore the fundamental processes of fault mechanics and the significance of the seismic response. These results can be directly compared to existing geophysical and geologic information from decollement zones.

  1. Experimental investigation of flash pyrolysis oil droplet combustion

    DEFF Research Database (Denmark)

    Ibrahim, Norazana; Jensen, Peter A.

    2013-01-01

    The aim of this work is to investigate and compare the combustion behaviour of a single droplet of pyrolysis oil derived from wheat straw and heavy fossil oil in a single droplet combustion chamber. The initial oil droplet diameters were in between 500 ?m to 2500 ?m. The experiments were performed at a temperature ranging between 1000 and 1400°C with an initial gas velocity of 1.6 m/s and oxygen concentration of 3%. The evolution of combustion of bio-oil droplets was recorded by a digital video camera. It was observed that the combustion behaviour of pyrolysis oil droplet differ from the heavy oil in terms both of ignition, devolatilisation and char oxidation. The pyrolysis oil is more difficult to ignite and has a shorter devolatilisation time and a longer char oxidation time. Copyright © 2013, AIDIC Servizi S.r.l.

  2. Experimental investigation on wax-filled superconducting solenoids

    International Nuclear Information System (INIS)

    The test results of about fifty wax-filled superconducting solenoids are summarized. These experiments have proved that high current density wax-filled solenoids can reach or approach short-sample performance. After many room temperature-liquid nitrogen temperature thermal cycles the performance of the magnet is stable. Different technology of wax filling has ben investigated. The largest tested magnet has a bore of 400 mm, energy about 0.4 Mj. Its maximal field is about 5.2 T, current density of the NbTi superconductor is 9X104 A/cm2 and overall current density is about 2.2X104 A/cm2. 1 ref

  3. Experimental investigations into the physics of light emitting conjugated polymers

    CERN Document Server

    Whitelegg, S A

    2001-01-01

    chloroprecursor MEH-PPV in-situ of ITO results in a reaction of the polymer with ITO, which significantly shift the emission to high energies. Electroabsorption spectroscopy is used to probe the internal electric fields within operating polymer light emitting devices. When a PPV based LED in an oxygen/water atmosphere, degradation of the device occurs whereby an electric field develops, which opposes the applied electric field. This opposing electric field subsequently decays when the device is turned to its off state. Operating lifetimes and emission efficiencies of polymer light emitting devices are now approaching values suitable for the manufacture and sale of polymer light emitting based products. However, degradation and device performance still continues to be of chief concern and in order for these to be improved the underlying physical processes have to be identified. This thesis aims to identify some of these processes. An investigation in to the optical absorption and emission properties of insolub...

  4. A theoretical and experimental investigation of the H3 system

    International Nuclear Information System (INIS)

    The H3 system is the simplest triatomic neutral molecular species. The first part of this dissertation is a theoretical investigation of the H3 molecular system. Results of the ab initio quantum mechanical calculations for the lowest three electronic potential energy surfaces are given, as well as electronically nonadiabatic coupling elements between these states. All 3-D quantum mechanical theoretical investigations to date invoke the Born-Oppenheimer approximation and neglect nonadiabatic coupling of the nearby states. The H3 system exhibits a conical intersection near which this approximation breaks down. To obtain accurate theoretical estimates for H3 undergoing various dynamical processes, these nonadiabatic terms must be included. The second part of this dissertation involves the development and characterization of an intense source of trihydrogen molecules. The ultimate goal of this work is to fully characterize the metastable H3 molecules formed in this beam and to create a source of monoenergetic trihydrogen molecules whose translational energy would be continuously tunable from ?1--12 eV. The H3 molecule in its 2pz2A double-prime 2 electronic state is 5.85 eV higher and the 2px,y2E' repulsive ground state is 2.65 eV higher in energy than H + H2.17--20 Upon a vertical transition to the ground state, the 2pzz2A double-prime 2 state of H3 liberates about 3 eV of electronic energy with the remaining energy being channeled into vibration and rotation of the H + H2 dissociated system. In a collision with another molecule, this energy could become available for reaction along with the translational energy of these molecules (1--12 eV). This species may undergo novel chemical reactions as well as unique partitioning of the available energy into electronic vibrational, rotational and translational energy of the products

  5. Experimental Investigation of Aerosols Produced by Cosmic Rays

    DEFF Research Database (Denmark)

    Pedersen, Jens Olaf Pepke; Enghoff, Martin Andreas BØdker

    Satellite observations have shown that the Earth’s cloud cover is strongly correlated with the galactic cosmic ray flux. While this correlation is indicative of a possible physical connection, there is currently no confirmation that a physical mechanism exists. We are therefore setting up an experiment in order to investigate the underlying microphysical processes. The results of this experiment will help to understand whether ionisation from cosmic rays, and by implication the related processes in the universe, has a direct influence on Earth’s atmosphere and climate. Since any physical mechanism linking cosmic rays to clouds and climate is currently speculative, there have been various suggestions of the role atmospheric ions may play; these involve any one of a number of processes from the nucleation of aerosols up to the collection processes of cloud droplets.We have chosen to start our investigation at the smallest scales, namely the role of cosmic ray produced ions on atmospheric aerosol nucleation andgrowth processes. Aerosol theory suggests that this is one of the most promising areas to search for an effect. However, guided by the nature of our initial results, it will be possible to develop the experiment to cover additional processes involved in the route to cloud droplet formation. The experiment will be conducted at the Danish National Space Center where a clean room facility has been provided. It comprises an 8 m3 reaction chamber across which an electric field is applied to control the number of ions present. This will enable experiments to be performed both with and without the presence of ions, thus providing information as to the potential role of ions in aerosol processes.

  6. Cloning Yeast Actin cDNA Leads to an Investigative Approach for the Molecular Biology Laboratory

    Science.gov (United States)

    Black, Michael W.; Tuan, Alice; Jonasson, Erin

    2008-01-01

    The emergence of molecular tools in multiple disciplines has elevated the importance of undergraduate laboratory courses that train students in molecular biology techniques. Although it would also be desirable to provide students with opportunities to apply these techniques in an investigative manner, this is generally not possible in the…

  7. LABORATORY INVESTIGATIONS OF THE DEPOSITION OF OXIDATION OF HYDROCHLOROFLUOROCAROBNS (HCFCS) AND HYDROFLUOROCARBONS (HFCS) TO AQUEOUS SOLUTIONS

    Science.gov (United States)

    Laboratory experiments were conducted to investigate the deposition to aqueous media of the gas phase oxidation products of the following hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs): CFC-22 (CClF2H), HFC-41, (CH3F), HCFC-123 (CCl2HCF3), HCFC-124 (CClFHCF3), HFC...

  8. Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms

    Science.gov (United States)

    Perera, Alokya P.; Bopegedera, A. M. R. P.

    2014-01-01

    The increase in ocean acidity since preindustrial times may have deleterious consequences for marine organisms, particularly those with calcareous structures. We present a laboratory experiment to investigate this impact with general, introductory, environmental, and nonmajors chemistry students. For simplicity and homogeneity, calcite was…

  9. The development and testing of a 2D laboratory seismic modelling system for heterogeneous structure investigations

    Science.gov (United States)

    Mo, Yike; Greenhalgh, Stewart A.; Robertsson, Johan O. A.; Karaman, Hakki

    2015-05-01

    Lateral velocity variations and low velocity near-surface layers can produce strong scattered and guided waves which interfere with reflections and lead to severe imaging problems in seismic exploration. In order to investigate these specific problems by laboratory seismic modelling, a simple 2D ultrasonic model facility has been recently assembled within the Wave Propagation Lab at ETH Zurich. The simulated geological structures are constructed from 2 mm thick metal and plastic sheets, cut and bonded together. The experiments entail the use of a piezoelectric source driven by a pulse amplifier at ultrasonic frequencies to generate Lamb waves in the plate, which are detected by piezoelectric receivers and recorded digitally on a National Instruments recording system, under LabVIEW software control. The 2D models employed were constructed in-house in full recognition of the similitude relations. The first heterogeneous model features a flat uniform low velocity near-surface layer and deeper dipping and flat interfaces separating different materials. The second model is comparable but also incorporates two rectangular shaped inserts, one of low velocity, the other of high velocity. The third model is identical to the second other than it has an irregular low velocity surface layer of variable thickness. Reflection as well as transmission experiments (crosshole & vertical seismic profiling) were performed on each model. The two dominant Lamb waves recorded are the fundamental symmetric mode (non-dispersive) and the fundamental antisymmetric (flexural) dispersive mode, the latter normally being absent when the source transducer is located on a model edge but dominant when it is on the flat planar surface of the plate. Experimental group and phase velocity dispersion curves were determined and plotted for both modes in a uniform aluminium plate. For the reflection seismic data, various processing techniques were applied, as far as pre-stack Kirchhoff migration. The irregular surface layer and the anomalous velocity block inserts can destroy the coherence of the reflections. Migration was able to resolve the two main buried interfaces when the surface layer was flat but for the variable irregular surface layer the imaging result is inferior. First-arrival tomography was applied to the crosshole seismic data set and yielded the correct velocity distributions. Numerical modelling was also carried out to replicate the laboratory data and to identify the arrivals. The numerical seismograms are of superior quality to the physical model data and yield improved images of the structures.

  10. The ideal flip-through impact: experimental and numerical investigation

    DEFF Research Database (Denmark)

    Bredmose, Henrik; Hunt-Raby, A.

    2010-01-01

    Results from a physical experiment and a numerical computation are compared for a flip-through type wave impact on a vertical face, typical of a seawall or breakwater. The physical wave was generated by application of the focused-wave group technique to the amplitudes of a JONSWAP spectrum, with the focus location adjusted to produce a near-breaking wave impact with no discernible air entrainment or entrapment. Details of the resultant impact are presented in the form of high-speed video, pressure transducer and wave gauge records. Numerical reproduction of the wave transformation and impact is achieved by application of a linear wave-analysis model and a fully nonlinear potential-flow solver. Although more advanced models exist, use of the latter model type is interesting as (1) it was applied by Cooker and Peregrine (Proceedings of the 22nd International Conference on Coastal Engineering, 164-176, 1990) in their original numerical discovery of the flip-through impact and (2) the assumptions behind the potential-flow model remain reasonably valid, until the flip-through jet begins to break into droplets. In the present study, the potential-flow model has been extended with the Schwarz-Christoffel conformal mapping, to allow a piece-wise linearly shaped mound geometry. Further, an ad-hoc wave-generation technique has been added, to facilitate an adequate numerical reproduction of long second-order waves in the flume. Free-surface elevations from the potential-flow computations show good agreement with wave gauge data for the wave that produces the flip-through impact. Experimental video frames with the corresponding numerical free-surface profiles overlaid show an excellent match for the flow contraction prior to impact. The deviations between the experiment and numerical solution that occur at the stage of jet formation are discussed and a computation of a slightly weaker impact illustrate the strong sensitivity of impact pressures to the shape of the impacting wave. Ways of improving the numerical description by use of more advanced models are outlined.

  11. Experimental investigation of small-scale gasification of woody biomass

    Energy Technology Data Exchange (ETDEWEB)

    Barrio, Maria

    2002-05-01

    A small-scale stratified down draft gasifier has been built and operated under stable conditions using wood pellets as fuel and air as gasification agent. The problems observed during the preliminary experiments have been described and explained; they are mainly related to the stability of the process. The stable operation of the gasifier has been characterised by the gas composition and the product gas tar and particle content. The biomass feeding rate has varied between 4,5 and 6,5 kg/h. The CO content of the product gas (23-26 % vol.) is higher than in similar gasifiers and the H{sub 2} content has been found to vary between 14 and 16 % vol. The tar content in the product gas (Ca. 3 g/Nm{sup 3}) is rather high compared with similar gasifiers. The temperature profile, together with other relevant parameters like the air-excess ratio, the air to fuel ratio and gas to fuel ratio have been calculated. The experiments show that the air excess ratio is rather constant, varying between 0,25 and 0,3. Experiments have been conducted with a gas engine using mixtures of CH{sub 4}, CO, H{sub 2}, CO{sub 2} and N{sub 2} as a fuel. NO{sub x} and CO emissions are analysed. The char gasification process has been studied in detail by means of Thermogravimetric Analysis. The study comprises the chemical kinetics of the gasification reactions of wood char in CO{sub 2} and H{sub 2}O, including the inhibition effect of CO and H{sub 2}. A kinetic model based on Langmuir-Hinshelwood kinetics has been found which relates the mass loss rate to the temperature, gas composition and degree of conversion for each reaction. The ratio CO/CO{sub 2} has been found to be a relevant parameter for reactivity. The gasification experiments in mixtures of CO{sub 2} and H{sub 2}O give reasons to believe that the rate of desorption for the complex C(O) varies depending on the gas mixture surrounding the char. It has been found that if the experimental data are obtained from separate H{sub 2}O/N{sub 2} and CO{sub 2}/N{sub 2} experiments, the reactivity of the char in mixtures of CO{sub 2} and H{sub 2}O can be fairly predicted. (author)

  12. An Experimental Investigation on Structural Behaviour of Beam Column Joint

    Directory of Open Access Journals (Sweden)

    Naveen Hooda

    2013-08-01

    Full Text Available Conventional concrete loses its tensile resistance afterthe formation of multiple cracks. However, fibrous concrete cansustain a portion of its resistance following cracking to resistmore loading. The strength of concrete is appreciably increasedby the crack arresting mechanism of the fibres and the ultimatestrength is also increased because extra energy is needed to causefracture of the fibre reinforcing the concrete. Beam-columnjoints have a crucial role in the structural integrity of thebuildings. For this reason they must be provided with adequatestiffness and strength to sustain the loads transmitted from beamand columns. For adequate ductility of beam-column joints, useof closely spaced hoops as transverse reinforcement wasrecommended. In the present study an attempt has been made toinvestigate the behaviour of exterior beam-column joint withdifferent detailing of reinforcement, different spacing ofconnecting ties and with different percentage of steel fibres.Initially three specimens (SP1, SP2 and SP3 with differentdetailing of reinforcement were tested. Then specimen SP2 wasselected for further investigation based on its structuralperformance and ease of detailing. Two more Specimens weretested with different spacing of ties/stirrups. Finally, toinvestigate the effect of addition of fibres on behaviour ofperformance of joints, three specimens (SP6, SP7 and SP8 withvolume fractions of 0.5%, 1.0% and 1.5% steel fibres were castand tested.The results obtained from the investigation indicated thataddition of steel fibres in the concrete mix improved structuralperformance of beam column joints measured in terms ofultimate load carrying capacity, stiffness, crack width, deflectionand curvature ductility factor. Steel fibre reinforced concrete isone of the possible alternative solutions for reducing thecongestion of transverse reinforcement in beam column joints.Thus with the reduction of congestion of reinforcement in thejoint core helps in the ease of construction difficulties, whilemaintaining ductile behaviour of the frame, With the increase inthe percentage of fibres from 0.05% to1.5% in the joint core thedeflection and curvature at peak load increased. Specimen SP8containing 1.5% of steel fibre in the joint core have higher valueof rotation (?, as compared with conventional specimenSP2.This clearly shows that the congestion of reinforcement inthe core of beam column joint can be reduced by the addition ofsteel fibre in the joint core with increase in the spacing ofhoops/ties. It was also observed in the study that the deflectionand curvature also increases with the decrease in spacing ofhoops/tie.

  13. Experimental investigation of a conical helicon double layer thruster arrangement

    Energy Technology Data Exchange (ETDEWEB)

    Charles, C; Cox, W; Boswell, R W [Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, Australian National University, ACT 0200 (Australia); Laine, R; Perren, M, E-mail: christine.charles@anu.edu.a [ASTRIUM-EADS, 6, rue Laurent Pichat, 75016 Paris (France)

    2010-08-15

    A conical pyrex plasma source with a conical helicon antenna surrounded by two cylindrically wound solenoids has been used in a helicon double layer thruster (HDLT) arrangement with the aim of investigating a new plasma cavity geometry and imposing a misalignment between the geometric and magnetic axis. An ion beam is measured with an energy analyser placed 6 cm downstream of the source exit for a low pressure argon plasma ({approx}0.4 mTorr) for various currents in the two solenoids. Operation with current in the exhaust solenoid only also shows the presence of the ion beam. For a given radiofrequency power and similar total solenoidal current, the ion beam current measured downstream of the conical HDLT is about seven times greater than that previously measured downstream of the cylindrical HDLT. This may result from a larger plasma density in the source and from a source peak density shift by about 10 cm towards the tube exit measured in the conical arrangement compared with previous observations in the cylindrical arrangement. When an angle between the geometric and magnetic axis of up to 9{sup 0} is mechanically imposed, the ion beam is detected for angles less than 5{sup 0}.

  14. Experimental investigation on CHF of tight lattice PWRs

    International Nuclear Information System (INIS)

    Improved fuel utilization is possible in tight-lattice PWR cores currently under development within a cooperation of the Karlsruhe Nuclear Research Center (KfK), the Swiss Paul-Scherrer-Institute (PSI), the Siemens/KWU and the Technical University of Braunschweig (TUBS). The hexagonal tightly-packed cores of a Pressurized Water High Converter Reactor (PWHCR) employ higher mass fluxes than conventional PWRs. PWHCR fuel assemblies (FA) if compared with PWR-FA have distinct fluid flow cross sections and obstructions. Also typical heat flux distributions (local peaks) call for appropriate thermal hydraulic models (average and local heat transfer, mixing, CHF). The scarcity of CHF data available for this kind of problem is obvious. For these reasons a broad framed investigation program on tight lattice two-phase mixing and boiling heat transfer has been organized at KfK in a scientific cooperation with TUBS. Performance characteristics of the recently erected Freon test facility KRISTA and some principal CHF results will be discussed to describe actual aspects and goals of the thermal hydraulic model fluid based program. The parallel efforts to develop scaling laws for a transformation of Freon flow boiling results into water equivalent data will be outlined. Final concern is related to the long term replacement of CFC-12 by Ozone-harmless fluids. (author). 17 refs, 10 figs, 2 tabs

  15. Experimental investigation of two-dimensional shock boundary layer interactions

    Science.gov (United States)

    Skebe, S. A.

    Experiments were performed on the interaction of oblique shock waves with flat plate boundary layers in the forward test section of the 30.48 cm. x 30.48 cm. (1 ft. x 1 ft.) Supersonic Wind Tunnel at the NASA-Lewis Research Center. Measurements of the plate surface static pressure and shear stress distributions as well as boundary layer velocity profiles were obtained through the interaction region. Flow conditions for these investigations encompassed a Mach number set from 2.0 to 4.0 and an overall unit Reynolds number range of 4.72E6 to 2.95E7 /m. The findings presented herein provide a complete description of two-dimensional interactions with initially laminar boundary layers over the Mach number range 2.0 to 4.0. Additional information with regard to interactions involving initially transitional boundary layers is provided over the Mach number range 2.0 to 3.0 and those for initially turbulent boundary layers at Mach 2.0. The experiments were motivated with achievement of benchmark results as their primary goal, in order to yield detailed information of high accuracy for service as a test case of analytic and numeric schemes of the present and future.

  16. Experimental investigation of tearing-instability phenomena for structural materials

    International Nuclear Information System (INIS)

    The objective of this investigation was to extend the range of tearing-instability validation experiments utilizing the compact specimen to include high-toughness alloys. J-Integral tests of ASTM A106; ASTM A516, Grade 70; ASTM A533B; HY-80; and HY-130 steels were performed in a variably compliant screw-driven test machine. Results were analyzed with respect to the materials J/sub I/-R curves and various models of T/sub applied/ for the compact specimen. Tearing instability theory was validated for these high-toughess materials. For the cases of highly curved J/sub I/-R curves, it was shown that the actual value of T/sub material/ at the point of instability should be employed rather than the average T/sub material/ value. The T/sub applied/ analysis of Paris and coworkers applied to the compact specimen appears to be nonconservative in predicting the point of instability; whereas, the T/sub applied/ analysis of Ernst and coworkers appears to be accurate, but requires precision beyond that displayed in this program. The generalized Paris analysis applied to the compact specimen and evaluated at maximum load was most consistent in predicting instability. 16 figures, 3 tables

  17. Experimental investigation on fiber laser cutting of aluminium thin sheets

    Science.gov (United States)

    Scintilla, Leonardo Daniele

    2014-02-01

    The most extensively used lasers for aluminum and its alloys cutting, are CO2 and Nd:YAG operating in continuous wave and pulsed mode. High power solid state fiber lasers operating in continuous wave mode offer a great potential in improving the cut quality and productivity of highly reflective materials cutting process due to the better absorptivity of 1 ?m laser radiation. The high processing speeds of CW mode and a good cut quality could be achieved at the same time. In this work, cutting experiments were performed on Al1050 1mm thick sheets using a fiber laser and Nitrogen as assist gas. A DOE approach that consists of fitting the regression models by means of response surface method (RSM) was adopted. The effects of cutting speed, focal position and assist gas pressure on dross height, kerf width and roughness parameters were investigated. Results showed that processing in CW with fiber laser increases the cutting speed and gives a cut quality comparable with results obtained with CO2 and Nd:YAG lasers and reported in literature.

  18. Experimental investigation of the critical ionization velocity in gas mixtures

    International Nuclear Information System (INIS)

    The critical ionization velocity which is of cosmogonic and astrophysical interest has hitherto mainly been investigated for pure gases. Since in space there are always gas mixtures, it is of interest also to study gas mixtures. The present report, which is a summary of a more detailed report (Axnas, 1976), summarizes the results of systematic experiments on the critical ionization velocity as a function of the mixing ratio for binary gas mixtures of H2, He, N2, O2, Ne and Ar. The apparatus used is a coaxial plasma gun with an azimuthal magnetic field. The discharge parameters are chosen so that the plasma is weakly ionized. In some of the mixtures it is found that one of the components tends to dominate in the sense that only a small amount (regarding volume) of that component is needed for the discharge to adopt a limiting velocity close to that for the pure component. Thus in a mixture between a heavy and a light component having nearly equal ionization potentials, the heavy component dominates. Also , if there is a considerable difference in ionization potential between the components, the component with the lowest ionization potential tends to dominate. (Auth.)

  19. An experimental investigation of the normality of irrational algebraic numbers.

    DEFF Research Database (Denmark)

    Nielsen, Johan Sejr Brinch; Simonsen, Jakob Grue

    2013-01-01

    We investigate the distribution of digits of large prefixes of the expansion of irrational algebraic numbers to different bases. We compute 2.318 bits of the binary expansions (corresponding to 2.33.108 decimals) of the 39 least Pisot-Vijayaraghavan numbers, the 47 least known Salem numbers, the least 20 square roots of positive integers that are not perfect squares, and 15 randomly generated algebraic irrationals. We employ these to compute the generalized serial statistics (roughly, the variant of the ?2-statistic apt for distribution of sequences of characters) of the distributions of digit blocks for each number to bases 2, 3, 5, 7 and 10, as well as the maximum relative frequency deviation from perfect equidistribution. We use the two statistics to perform tests at significance level ? = 0.05, respectively, maximum deviation threshold ? = 0.05. Our results suggest that if Borel's conjecture-that all irrational algebraic numbers are normal-is true, then it may have an empirical base: The distribution of digits in algebraic numbers appears close to equidistribution for large prefixes of their expansion. Of the 121 algebraic numbers studied, all numbers passed the maximum relative frequency deviation test in all considered bases for digit block sizes 1, 2, 3, and 4; furthermore, 92 numbers passed all tests up to block size 4 in all bases considered.

  20. An experimental investigation into the atmospheric degradation of piperazine

    Science.gov (United States)

    White, Stephen; Angove, Dennys; Azzi, Merched; Tibbett, Anne; Campbell, Ian; Patterson, Michael

    2015-05-01

    The atmospheric degradation of piperazine was investigated using an indoor smog chamber. Experiments were carried out in the presence of nitrogen oxides (NOx), ozone or nitric acid. Piperazine reacted rapidly under all evaluated conditions: irradiated in the presence of NOx and with ozone and nitric acid in the dark. Gas phase products from the oxidation of piperazine were identified by infrared spectroscopy, DNPH cartridges followed by HPLC analysis, and by sampling chamber gas through Tenax sorbent material followed by analysis using thermal desorption GC-ITMS (gas chromatography ion trap mass spectrometry). Eight compounds were positively identified, with a further nine compounds tentatively identified using GC-MS based on molecular weight and mass spectra. Ammonia formation was observed from piperazine oxidation, and its formation was from the subsequent reactions of photooxidation products of piperazine rather than directly from the reaction of piperazine. The nitrosamine and nitramine expected from piperazine, N-nitrosopiperazine, and N-nitropiperazine, were both identified and confirmed using 15NO, with a tentative maximum yield of nitrosamine of less than 5% observed. Aerosol yields, relative to total piperazine reacted not including that which absorbed to the walls, were considerably high but were not able to be quantified absolutely due to unusual behaviour of the scanning mobility particle sizer instrument to aerosol containing amines. The reaction of piperazine with gas phase nitric acid gave rise to immediate formation of aerosol.

  1. Experimental investigation of CO2 condensation process using cryogen

    International Nuclear Information System (INIS)

    Carbon dioxide (CO2) is one of the dominant gas molecules that causes greenhouse effect, i.e. global warming. Numerous studies have been carried out to regulate the emission of CO2 to reduce greenhouse gas. The liquid CO2 is a convenient form of transportation compared to high-pressurized gaseous CO2. Therefore, the direct liquefaction mechanism of CO2 at low temperature draws technical attention recently. In particular, cold thermal energy of Liquefied Natural Gas (LNG) could be a candidate to condense gaseous CO2, especially in the LNG powered ship. In this paper, the detailed direct condensation process of CO2 using LN2 with intermittent solidification is investigated. Pressurized CO2 at 600 kPa is directly liquefied in a vessel by liquid nitrogen which is supplied into the coiled tube heat exchanger inside the CO2 vessel. The heat exchanger temperature is controlled from 130 K to 205 K to regulate the solidification and sublimation of CO2 by duty control with cryogenic solenoid valve. The characteristics of CO2 condensation process with cryogen are analyzed from the measurement results. The results show that the solidification causes the significant degradation of CO2 condensation heat transfer. Finally, the condensation rate with and without solidification is compared

  2. Experimental investigation of plasma-neutralized operation of a gyrotron

    International Nuclear Information System (INIS)

    The authors present plans and preliminary results of an experiment to investigate the effects of a neutralizing background plasma on the operation of a gyrotron oscillator. Previous experiments operating without a neutralizing background plasma achieved output powers P = 100 - 250MW at a frequency f = 35 GHz, with beam voltages in the range V = 0.60 - 1.35MV, and beam currents I = 1 -3kA. A completely ionized plasma is injected into a gyrotron interaction region from an upstream array of plasma guns. The peak plasma density available from the plasma guns exceeds np > 1013 cm-3. The plasma density is measured by 70 GHz microwave interferometry and Langmuir probes. A high current electron beam from a field emission electron gun enters the plasma-filled gyrotron cavity from the upstream side. The density of the neutralizing plasma is varied by changing the delay between the firing of plasma guns and the VEBA accelerator. The authors present measurements of the transmitted electron beam current. Subsequent design of a gyrotron oscillator which utilizes the enhanced capabilities are presented

  3. An experimental investigation of proton-induced phenomena in krypton

    International Nuclear Information System (INIS)

    In this thesis proton-induced phenomena in krypton gas are described. The considered reactions of protons on krypton are both nuclear and atomic. The nuclear conversion processes mainly result in the production of several Rb radioisotopes, such as 81Rb that is used in 81Rb-sup(81m)Kr generator systems for medical diagnostics. The irradiation of krypton gas (natural composition) with protons of about 26 MeV can be used for the routine production of 81Rb from the direct production reaction 82Kr(p,2n)81Rb and from the indirect reaction 82Kr(p,2n)sup(81m)Rb ? 81Rb. To determine the scattering of protons in krypton gas targets a quantitative autoradiographic technique was developed. Proton profiles have been determined from the proton-induced activity distribution on a copper foil. For the on-line detection of produced Rb radioisotopes several optical detection techniques were investigated. (Auth.)

  4. Experimental Investigation of Actuators for Flow Control in Inlet Ducts

    Science.gov (United States)

    Vaccaro, John; Elimelech, Yossef; Amitay, Michael

    2010-11-01

    Attractive to aircraft designers are compact inlets, which implement curved flow paths to the compressor face. These curved flow paths could be employed for multiple reasons. One of which is to connect the air intake to the engine embedded in the aircraft body. A compromise must be made between the compactness of the inlet and its aerodynamic performance. The aerodynamic purpose of inlets is to decelerate the oncoming flow before reaching the engine while minimizing total pressure loss, unsteadiness and distortion. Low length-to-diameter ratio inlets have a high degree of curvature, which inevitably causes flow separation and secondary flows. Currently, the length of the propulsion system is constraining the overall size of Unmanned Air Vehicles (UAVs), thus, smaller more efficient aircrafts could be realized if the propulsion system could be shortened. Therefore, active flow control is studied in a compact (L/D=1.5) inlet to improve performance metrics. Actuation from a spanwise varying coanda type ejector actuator and a hybrid coanda type ejector / vortex generator jet actuator is investigated. Special attention will be given to the pressure recovery at the AIP along with unsteady pressure signatures along the inlet surface and at the AIP.

  5. Experimental investigation of electrohydrodynamic instabilities in micro channels

    Science.gov (United States)

    Eribol, P.; Uguz, A. K.

    2015-03-01

    An electric field is applied to destabilize the interface between two Newtonian and immiscible liquids flowing in a rectangular micro channel. The liquids are pumped into the micro channel with a syringe pump and a DC electric field is applied either parallel or normal to the flat interface between these liquids. The two liquids used in the experiments are a combination of ethylene glycol, different viscosity silicone oils, castor oil, and olive oil. The onset of electrohydrodynamic instability is investigated for various parameters, including the ratios of the flow rates, and viscosities of the liquids, the width of the micro channel, and the direction of the applied electric field. The order of the voltage applied to destabilize the interface is in the range 95 and 1190 V. The results of the experiments show that an increase in the viscosity ratio and the flow rate ratio of silicone oil to ethylene glycol have a stabilizing effect. It is also found that the important parameter to determine the critical voltage is the flow rate ratio, not the individual flow rates of the liquids. Also, as the width of the micro channel increases, the critical voltage increases. Lastly, for the liquid combinations used in the experiments, the interface could not be destabilized under the influence of a parallel electric field.

  6. Experimental investigation on cryogenic hydrogen adsorption of molecular sieves

    Energy Technology Data Exchange (ETDEWEB)

    Qian Xiaojing, E-mail: eagleqq@sohu.com [China Academy of Engineering Physics, P.O. Box 919-71, Mianyang 621900, Sichuan (China); Luo Deli; Huang Guoqiang; Song Xiaojing; Liu Weidong [China Academy of Engineering Physics, P.O. Box 919-71, Mianyang 621900, Sichuan (China)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Seven kinds of domestic molecular sieves had been tested at different pressure. Black-Right-Pointing-Pointer Globular MS5A-2 with a diameter of 3-5 mm could effectively extract trace hydrogen. Black-Right-Pointing-Pointer The saturated hydrogen adsorption capacity of MS5A-2 is 7.55 ml g{sup -1} (NTP). - Abstract: Tritium extraction system (TES) is one of the most important components in the helium cooled solid breeder test blanket modules (TBMs) of ITER. TES will extract various isotopic species of hydrogen by the liquid nitrogen cooled molecular sieve adsorber beds (MSB). The cryogenic hydrogen adsorption properties of several kinds of molecular sieves have been investigated at the pressure of hydrogen of 100 Pa, 200 Pa, and 0.2 MPa in order to offer the suitable molecular sieve for the MSB in TES. The saturated hydrogen adsorption capacities of the MS5A-2 and MS13X-2 have been measured at 100 Pa hydrogen pressure. To demonstrate the hydrogen extraction from continuous He-H{sub 2} purge gases, the MS5A-2 has been tested in circulating 99.79% He-0.21% H{sub 2} mixture with a flow rate of 16.8 L/min. The results show that the globular MS5A-2 with a diameter of 3-5 mm can adsorb/desorb hydrogen quickly. The saturated hydrogen adsorption capacity of MS5A-2 is 7.55 ml g{sup -1} (NTP) and MS5A-2 could effectively extract trace hydrogen from mixture gases. As a result, this type of molecular sieve can be the candidate of the one in the MSB in ITER TBM.

  7. Experimental investigation of polymer flow in injection mould

    Directory of Open Access Journals (Sweden)

    T. Jaruga

    2007-03-01

    Full Text Available Purpose: The examination of melt flow lines in injection moulded parts was the purpose of this research, as well as a new method of flow visualization was applied. This method can be helpful in predicting the weak areas in moulded parts, created during cavity fillingDesign/methodology/approach: The method of visualization used here is not classified yet. It allows to observe how the cavity is filled by looking at a specially created flow lines pattern. These lines are surface defects and a production injection moulding process it is necessary to avoid them. The effect of flow lines on the part surface occurs by special moulding conditions. To obtain the flow lines for investigation the mould temperature was lowered, the holding stage was skipped (the holding pressure not applied, and injection time had to be short enough.Findings: On the example of moulded plastic parts of simple shape it was found that the applied method of visualization allows to observe the filling process in mould cavity with good agreement to the theory and simulation results.Research limitations/implications: The flow lines cannot be observed for all plastics grades, but only for these which are sensitive to special processing conditions, like POM or PE. The flow conditions are not the same as in a typical injection moulding process.Practical implications: This method can be used in practice for melt flow examination in the case of more complicated cavities in injection moulds. The flow lines can be used to diagnose the problems during cavity filling, that are the reason of poor part quality, for example the undesired or unexpected weld lines location in parts.Originality/value: Usually the visible flow lines on part’s surface are treated as a defect. In this paper it was shown that it can be an easy method of flow visualization.

  8. An experimental investigation of chemical communication in the polar bear

    Science.gov (United States)

    Owen, Megan A.; Swaisgood, Ronald R.; Slocomb, C.; Amstrup, Steven C.; Durner, George M.; Simac, Kristin; Pessier, A. P.

    2015-01-01

    The polar bear (Ursus maritimus), with its wide-ranging movements, solitary existence and seasonal reproduction, is expected to favor chemosignaling over other communication modalities. However, the topography of its Arctic sea ice habitat is generally lacking in stationary vertical substrates routinely used for targeted scent marking in other bears. These environmental constraints may have shaped a marking strategy, unique to polar bears, for widely dispersed continuous dissemination of scent via foot pads. To investigate the role of chemical communication, pedal scents were collected from free-ranging polar bears of different sex and reproductive classes captured on spring sea ice in the Beaufort and Chukchi seas, and presented in a controlled fashion to 26 bears in zoos. Results from behavioral bioassays indicated that bears, especially females, were more likely to approach conspecific scent during the spring than the fall. Male flehmen behavior, indicative of chemosignal delivery to the vomeronasal organ, differentiated scent donor by sex and reproductive condition. Histologic examination of pedal skin collected from two females indicated prominent and profuse apocrine glands in association with large compound hair follicles, suggesting that they may produce scents that function as chemosignals. These results suggest that pedal scent, regardless of origin, conveys information to conspecifics that may facilitate social and reproductive behavior, and that chemical communication in this species has been adaptively shaped by environmental constraints of its habitat. However, continuously distributed scent signals necessary for breeding behavior may prove less effective if current and future environmental conditions cause disruption of scent trails due to increased fracturing of sea ice.

  9. Experimental investigation on cryogenic hydrogen adsorption of molecular sieves

    International Nuclear Information System (INIS)

    Highlights: ? Seven kinds of domestic molecular sieves had been tested at different pressure. ? Globular MS5A-2 with a diameter of 3–5 mm could effectively extract trace hydrogen. ? The saturated hydrogen adsorption capacity of MS5A-2 is 7.55 ml g?1 (NTP). - Abstract: Tritium extraction system (TES) is one of the most important components in the helium cooled solid breeder test blanket modules (TBMs) of ITER. TES will extract various isotopic species of hydrogen by the liquid nitrogen cooled molecular sieve adsorber beds (MSB). The cryogenic hydrogen adsorption properties of several kinds of molecular sieves have been investigated at the pressure of hydrogen of 100 Pa, 200 Pa, and 0.2 MPa in order to offer the suitable molecular sieve for the MSB in TES. The saturated hydrogen adsorption capacities of the MS5A-2 and MS13X-2 have been measured at 100 Pa hydrogen pressure. To demonstrate the hydrogen extraction from continuous He–H2 purge gases, the MS5A-2 has been tested in circulating 99.79% He–0.21% H2 mixture with a flow rate of 16.8 L/min. The results show that the globular MS5A-2 with a diameter of 3–5 mm can adsorb/desorb hydrogen quickly. The saturated hydrogen adsorption capacity of MS5A-2 is 7.55 ml g?1 (NTP) and MS5A-2 could effectively extract trace hydrogen from mixture gases. As a result, this type of molecular sieve can be the candidate of the one in the MSB in ITER TBM.

  10. Experimental investigation of Mars meandering rivers: Chemical precipitation process

    Science.gov (United States)

    Kim, W.; Lim, Y.; Cleveland, J.; Reid, E.; Jew, C.

    2014-12-01

    On Earth, meandering streams occur where the banks are resistant to erosion, which enhances narrow and deep channels. Often this is because the stream banks are held firm by vegetation. The ancient, highly sinuous channels with cutoffs found on Mars are enigmatic because vegetation played no role in providing bank cohesion and enhancing fine sediment deposition. Possible causes of the meandering therefore include ice under permafrost conditions and chemical processes. We conducted carbonate flume experiments to investigate possible mechanisms creating meandering channels other than vegetation. The experiment includes a tank that dissolves limestone by adding CO2 gas and produces artificial spring water, peristaltic pumps to drive water through the system, a heater to control the temperature of the spring water, and a flume where carbonate sediment deposits. Spring water containing dissolved calcium and carbonate ions moves through a heater to increase temperature, and then into the flume. The flume surface is open to the air to allow CO2 degassing, decrease temperature, and increase pH, which promotes carbonate precipitation. A preliminary experiment was done and successfully created a meander pattern that evolved over a 3-day experiment. The experiment showed lateral migration of the bend and avulsion of the stream, similar to a natural meander. The lateral variation in flow speed increased the local residence time of water, thus increasing the degassing of CO2 on the two sides of the flow and promoting more precipitation. This enhanced precipitation on the sides provided a mechanism to build levees along the channel and created a stream confined in a narrow path. This mechanism also potentially applies to Earthly single thread and/or meandering rivers developed and recorded before vegetation appeared on Earth's surface.

  11. Experimental investigation of magneto-photo-phonon resonance

    International Nuclear Information System (INIS)

    Full text: Recently, Xu and Zhang proposed that magneto-photo-phonon resonances (MPPR) may appear in two-dimensional semiconductor systems driven by terahertz electromagnetic radiation. The resonance condition may be written as ? + N?C = ?LO, where N is an integer and ?, ?C and ?LO are the photon, cyclotron and longitudinal-optic phonon frequencies, respectively. Physically, an increase in longitudinal resistivity, pxx, is expected when an inter-Landau-level transition, coupled with optical absorption, leads to resonant scattering via LO-phonon emission. The MPPR may be investigated either by sweeping magnetic field at a fixed photon energy or by scanning photon energy (i.e. spectroscopy) at a fixed magnetic field. Our experiments embrace both approaches. We have examined a variety of GaAs-based two-dimensional electron gases. In GaAs, ?LO ? 56 THz, corresponding to a magnetic field of ?21 T. Using a filtered 'globar' (broadband) source of THz radiation, no shift in the usual magneto-phonon resonance (MPR) was observed. At a fixed magnetic field corresponding to an MPR, the resistivity modulation due to the THz radiation was so small that no zero-path difference maximum could be detected in the interferogram of the Fourier spectrometer. Measurements using a much stronger source of radiation, an optically-pumped molecular laser, yielded sharp cyclotron resonance at low temperature (4 K), but nat low temperature (4 K), but no optical effects were detected at the high temperatures (150 K) required for MPPR, although the usual MPR was again observed. Use of a still stronger source, a free-electron laser, permitted observation of cyclotron resonance features at 150 K, but again no shift in the usual MPR which might be attributed to MPPR. We conclude from these experiments that the direct optical process of cyclotron resonance is at least 100 times stronger than the proposed indirect process which would lead to MPPR

  12. Laboratory investigations of the hydroxyl radical-initiated oxidation of atmospheric volatile organic compounds

    Science.gov (United States)

    Vimal, Deepali

    The hydroxyl radical (OH) is one of the most important oxidants in the atmosphere, because reaction with OH is the dominant atmospheric fate of most trace atmospheric species. OH is intimately involved in a complex non-linear photochemical pathway involving anthropogenic and biogenic emissions of volatile organic compounds (VOCs) and nitrogen oxides that are emitted from vehicular exhaust and industrial emissions. This chemistry generates secondary tropospheric ozone which is an important greenhouse gas as well as a component of photochemical smog. In addition, this chemistry leads to the formation of secondary organic aerosols in the atmosphere which have implications for public health and climate change. The focus of this dissertation is to improve our understanding of this complex chemistry by investigating the rate-limiting elementary reactions which are part of the OH-initiated oxidation of important VOCs. Experimental (discharge flow technique coupled with resonance fluorescence and laser induced fluorescence) and theoretical studies (Density Functional Theory computations) of the kinetics of three atmospheric VOCs, acetic acid, 1,3-butadiene and methyl ethyl ketone are discussed. The acetic acid and OH reaction has been thought to undergo a hydrogen-bonded complex mediated pathway instead of a direct one leading to faster rate constants at lower temperature. Our results for the experimental investigation between 263-373 K and pressures of 2-5 Torr for the gas phase reaction of acetic acid with OH confirm the complex mediated reaction mechanism and indicate that acetic acid can play an important role especially in the oxidative chemistry of upper troposphere. The 1,3-butadiene and OH reaction is thought to undergo electrophilicaddition by OH which could display a complex pressure dependence similar to isoprene and 232-butenol as noted earlier in this laboratory. However, our results for the kinetics of the reaction between 273-423 K and a pressure range of 1-6 Torr indicate a lack of pressure independence owing to a more efficient scavenging of the intermediate butadiene-OH peroxy radicals by oxygen. The reaction of methyl ethyl ketone and OH has relatively few kinetic investigations and its reaction mechanism is thought to be similar to that of acetone, mediated by a hydrogen bonded prereactive complex. Our kinetic investigations between 2-5 Torr and 263-388 K confirm the above mechanism but are contrary to earlier product studies that suggest that the preferential abstraction of an alpha-hydrogen from MEK by OH takes place. Instead, based on the results of our kinetic isotope effect we propose that the reaction proceeds via the abstraction of beta-hydrogen. In addition, results from measurements and model simulations of OH and HO2 radicals in photooxidation of isoprene in a photochemical reaction chamber at Purdue University are presented. Isoprene is one of the most important reactive biogenic VOCs in the atmosphere because it can contribute to regional ozone production as well secondary organic aerosol production. Measurements of OH, isoprene and its oxidation products in an environmental chamber are compared to model predictions using the Regional Atmospheric Chemistry Mechanism to test and validate current models of isoprene oxidation in the atmosphere.

  13. Experimental and Computational of Engine Cylinder Pressure Investigation on the Port Injection Dedicated CNG Engine Development

    OpenAIRE

    Semin; A. R. Ismail; T.F. Nugroho

    2010-01-01

    This study has been investigated the effect of diesel engine convert to sequential port injection dedicated CNG engine on the engine cylinder pressure performance. This research has using GT-Power computational engine model for steady-state and transient simulation and experimental investigation. The investigation and simulation of the engine cylinder pressure performance characteristic profile based on variation engine speed. The engine computational model and experimental has developed base...

  14. Simulation and Experimentation in a Laboratory Curriculum for Non-Scientists

    Science.gov (United States)

    Maloney, F. P.; Maurone, P. A.; Hones, M. J.

    1994-12-01

    The availability of low-cost high-performance computing hardware and software has transformed the manner by which astronomical concepts can be re-discovered and explored in a laboratory that accompanies an astronomy course for non-scientist students. We present a strategy for allowing each student to understand fundamental scientific principles by interactively confronting astronomical and physical phenomena, through direct observation and by computer simulation. Direct observation of physical phenomena, such as Hooke's Law, begins by using a computer and hardware interface as a data-collection and presentation tool. In this way, the student is encouraged to explore the physical conditions of the experiment and re-discover the fundamentals involved. The hardware frees the student from the tedium of manual data collection and presentation, and permits experimental design which utilizes data that would otherwise be too fleeting, too imprecise, or too voluminous. Computer simulation of astronomical phenomena allows the student to travel in time and space, freed from the vagaries of weather, to re-discover such phenomena as the daily and yearly cycles, the reason for the seasons, the saros, and Kepler's Laws. By integrating the knowledge gained by experimentation and simulation, the student can understand both the scientific concepts and the methods by which they are discovered and explored. We present the laboratory experiments (also available via anonymous FTP from ASTRO4.AST.VILL.EDU), and information concerning the hardware and software requirements. This work is supported by a grant from The Pew Charitable Trusts.

  15. Horonobe Underground Research Laboratory project. Investigation report for the 2007 fiscal year

    International Nuclear Information System (INIS)

    The Horonobe Underground Research Laboratory Project 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 2007 fiscal year (2007/2008), the 3rd 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 2007 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)

  16. Inquiry-based laboratory investigations and student performance on standardized tests in biological science

    Science.gov (United States)

    Patke, Usha

    Achievement data from the 3rd International Mathematics and Sciences Study and Program for International Student Assessment in science have indicated that Black students from economically disadvantaged families underachieve at alarming rates in comparison to White and economically advantaged peer groups. The study site was a predominately Black, urban school district experiencing underachievement. The purpose of this correlational study was to examine the relationship between students' use of inquiry-based laboratory investigations and their performance on the Biology End of Course Test, as well as to examine the relationship while partialling out the effects of student gender. Constructivist theory formed the theoretical foundation of the study. Students' perceived levels of experience with inquiry-based laboratory investigations were measured using the Laboratory Program Variable Inventory (LPVI) survey. LPVI scores of 256 students were correlated with test scores and were examined by student gender. The Pearson correlation coefficient revealed a small direct correlation between students' experience in inquiry-based laboratory investigation classes and standardized test scores on the Biology EOCT. A partial correlational analysis indicated that the correlation remained after controlling for gender. This study may prompt a change from teacher-centered to student-centered pedagogy at the local site in order to increase academic achievement for all students. The results of this study may also influence administrators and policy makers to initiate local, state, or nationwide curricular development. A change in curriculum may promote social change as students become more competent, and more able, to succeed in life beyond secondary school.

  17. Experimental tests in the Sotacarbo laboratory scale coal-to-hydrogen plant

    Energy Technology Data Exchange (ETDEWEB)

    Alberto Pettinau; Francesca Ferrara; Alessandro Orsini; Gabriele Cali; Monica Caboni; Carlo Amorino [Sotacarbo S.p.A., Carbonia (Italy)

    2009-07-01

    Coal gasification represents one of the most promising technology for large, medium and small scale hydrogen production for distributed power generation. Currently, the application of 'zero emissions' hydrogen production and power generation technologies involves very high capital and operative costs. This need a great scientific and technical effort in order to optimize processes and equipments, thus reducing the hydrogen production cost. In this field, Sotacarbo has build up a pilot platform for a combined production of hydrogen and electrical energy from coal. The platform includes two different units: a 5 MWt pilot plant (with a fuel capacity of 700 kg/h of coal) and a 200 kWt 'laboratory scale' plant (feed with 35 kg/h of coal). In particular, the laboratory scale plant has been designed to develop and optimize the syngas treatment line for hydrogen production and power generation; therefore, the plant includes a fixed-bed up-draft gasifier, a syngas depulveration system, a cold and hot gas desulphurization processes, an integrated CO-shift and CO{sub 2} absorption system, a PSA section for hydrogen purification and a syngas-feed internal combustion engine for power generation. This paper reports a critical analysis of the main results obtained in the first experimental campaigns on the laboratory scale plant, with particular reference on coal gasification and hydrogen production. 16 refs., 8 figs., 4 tabs.

  18. The erosion of carbonate stone by acid rain: Laboratory and field investigations

    International Nuclear Information System (INIS)

    This paper describes a laboratory experiment on the effects of acidic deposition on carbonate stone erosion. It can serve as the basis for an undergraduate (or pre college) experiment in environmental chemistry. Recent field investigations are described that provide measurements of carbonate stone dissolution and mechanical erosion under weathering conditions that are prevalent in the eastern US. The purpose of the laboratory work is to answer questions concerning the effects of hydrogen ion deposition on stone erosion processes that were difficult to resolve on the basis of field experiments alone

  19. Environmental epidemiology applied to urban atmospheric pollution: a contribution from the Experimental Air Pollution Laboratory (LPAE) Epidemiologia ambiental aplicada à poluição atmosférica urbana: uma contribuição do Laboratório de Poluição Atmosférica Experimental (LPAE)

    OpenAIRE

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

    2000-01-01

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

  20. Single annular combustor: Experimental investigations of aerodynamics, dynamics and emissions

    Science.gov (United States)

    Mohammad, Bassam Sabry

    The present work investigates the aerodynamics, dynamics and emissions of a Single Cup Combustor Sector. The Combustor resembles a real Gas Turbine Combustor with primary, secondary and dilution zones (also known as fuel rich dome combustor). The research is initiated by studying the effect of the combustor front end geometry on the flow field. Two different exit configurations (one causes a sudden expansion to the swirling flow while the other causes a gradual expansion), installed in a dump combustor, are tested using LDV. The results reveal that the expanding surface reduces the turbulence activities, eliminates the corner recirculation zone and increases the length of the CRZ appreciably. An asymmetry in the flow field is observed due to the asymmetry of the expanding surface. To study the effect of chamber geometry on the flow field, the dome configuration is tested in the combustor sector with the primary dilution jets blocked. The size of the CRZ is reduced significantly (40% reduction in the height). With active primary jets, the CRZ is reconstructed in 3D by conducting several PIV measurements off-center. The confinement appears to significantly influence the shape of the CRZ such that the area ratio is similar for both the confinement and the CRZ (approximately 85%). The primary jets considerably contribute to the heat release process at high power conditions. Also, the primary jets drastically impact the flow field structure. Therefore, the parameters influencing the primary jets are studied using PIV (pressure drop, jets size, off-centering, interaction with convective cooling air, jet blockage and fuel injection). This study is referred to as a jet sensitivity study. The results indicate that the primary jets can be used effectively in controlling the flow field structure. A pressure drop of 4.3% and 7.6% result in similar flows with no noticeable effect on the size of the CRZ and the four jets wake regions. On the other hand, the results show that the primary jets are very sensitive to perturbations. The cooling air interacts with the primary jet and influences the flow field although the momentum ratio has an order of magnitude of 100:1. The results also show that the big primary jets dictate the flow field in the primary zone as well as the secondary zone. However, relatively smaller jets mainly impact the primary zone. Also, the results point to the presence of a critical jet diameter beyond which the dilution jets have minimum impact on the secondary region. The jet off-centering shows significant effect on the flow field though it is on the order of 1.0 mm. The jet sensitivity study provides the combustion engineers with useful methods to control the flow field structure, an explanation for observed flow structure under different conditions and predictable flow field behavior with engine aging. All results obtained from the jet sensitivity study could be explained in terms of jet opposition. Hence, similar results are expected under reacting conditions even though the results presented here are obtained under isothermal conditions. The fuel injection is also shown to influence the flow field. High fuel flow rate is shown to have very strong impact on the flow field and thus results in a strong distortion of both the primary and secondary zones. The jets wake regions are shown to change in size with fuel injection. The left jet wake region continuously reduces in size with fuel injection while the right jet wake region does not. This offers a possible explanation for the observed combustion instabilities in the left primary jet region. The combustion instabilities are studied using a microphone, high speed camera and regular cameras. The frequency spectrum for the sector is established at different pressure drops (2, 4 and 6%) as well as different pre-heat temperatures (200, 400 and 600F). The acoustic spectrum suggests that there are three frequencies of concern (280, 400 and 600 HZ). The high frequency appears to be related to the combustor ¼ longitudinal wave. The 280 Hz is due to a rotating instabi

  1. An experimental investigation of evolutionary dynamics in the Rock-Paper-Scissors game

    Science.gov (United States)

    Hoffman, Moshe; Suetens, Sigrid; Gneezy, Uri; Nowak, Martin A.

    2015-01-01

    Game theory describes social behaviors in humans and other biological organisms. By far, the most powerful tool available to game theorists is the concept of a Nash Equilibrium (NE), which is motivated by perfect rationality. NE specifies a strategy for everyone, such that no one would benefit by deviating unilaterally from his/her strategy. Another powerful tool available to game theorists are evolutionary dynamics (ED). Motivated by evolutionary and learning processes, ED specify changes in strategies over time in a population, such that more successful strategies typically become more frequent. A simple game that illustrates interesting ED is the generalized Rock-Paper-Scissors (RPS) game. The RPS game extends the children's game to situations where winning or losing can matter more or less relative to tying. Here we investigate experimentally three RPS games, where the NE is always to randomize with equal probability, but the evolutionary stability of this strategy changes. Consistent with the prediction of ED we find that aggregate behavior is far away from NE when it is evolutionarily unstable. Our findings add to the growing literature that demonstrates the predictive validity of ED in large-scale incentivized laboratory experiments with human subjects. PMID:25743257

  2. Investigations in the scintiscanning of joints of animals with experimental and rheumatoid arthritis

    International Nuclear Information System (INIS)

    In 69 guinea pigs with experimental hyperergic arthritis scintiscanning was done to study the course of the inflammation and the deposition of the radionuclides used. During the first days there was an added storage in the inflamed joints of those animals on whom scintiscanning with Tc99m04 had been performed. The accumulation of Tc99m04 in the joints was due to its uptake by synovial tissue and hydrarthrosis as shown by scintiscanning after haemorrhage and perfusion, macroscopic autoradiography and measurements of radioactivity in tissue samples. In 13 animals with rheumatoid arthritis scintiscanning was done twice with Tc99m04 and three times with Tc99mMDP over a period of 13 to 21 months; concomitantly laboratory tests and X-rays were conducted. After Tc99m04 there was a fall in the scintigraphic inflammation index during treatment. That index was determined by forming the quotient from the activities established above the proximal interphalangeal joints and the tibial head. Scintiscanning with Tc99mMDP led to a fall of the inflammation index in animals with classical rheumatoid arthritis, whereas in the ones with probable rheumatoid arthritis it again rose after an initial fall. Unlike x-ray investigation, scintiscanning permits an early diagnosis and course control. (orig.)

  3. An experimental investigation of evolutionary dynamics in the Rock-Paper-Scissors game.

    Science.gov (United States)

    Hoffman, Moshe; Suetens, Sigrid; Gneezy, Uri; Nowak, Martin A

    2015-01-01

    Game theory describes social behaviors in humans and other biological organisms. By far, the most powerful tool available to game theorists is the concept of a Nash Equilibrium (NE), which is motivated by perfect rationality. NE specifies a strategy for everyone, such that no one would benefit by deviating unilaterally from his/her strategy. Another powerful tool available to game theorists are evolutionary dynamics (ED). Motivated by evolutionary and learning processes, ED specify changes in strategies over time in a population, such that more successful strategies typically become more frequent. A simple game that illustrates interesting ED is the generalized Rock-Paper-Scissors (RPS) game. The RPS game extends the children's game to situations where winning or losing can matter more or less relative to tying. Here we investigate experimentally three RPS games, where the NE is always to randomize with equal probability, but the evolutionary stability of this strategy changes. Consistent with the prediction of ED we find that aggregate behavior is far away from NE when it is evolutionarily unstable. Our findings add to the growing literature that demonstrates the predictive validity of ED in large-scale incentivized laboratory experiments with human subjects. PMID:25743257

  4. Experimental investigation of a free-surface turbulent jet with Coanda effect

    Science.gov (United States)

    Miozzi, M.; Lalli, F.; Romano, G. P.

    2010-07-01

    The deviation of a jet from the straight direction due to the presence of a lateral wall is investigated from the experimental point of view. This flow condition is known as Coanda jet (from the Romanian aerodynamicist Henry Marie Coanda who discovered and applied it at the beginning of XXth century) or offset jet. The objective of the work is to detail the underlying mechanisms of such a phenomenon aiming to use it as a flow control method at polluted river flows mouth. To do this, a large laboratory free-surface tank with an incoming channel has been set up and velocity field measurements are performed by Optical Flow methods (namely Feature Tracking). Preliminary tests on the well-known free jet configuration without any marine structure ( i.e. lateral wall) are performed to allow comparison with free jet scaling and self-similar solutions. The presence of the free-surface gives rise to centerline velocity decay which is lower than in free unbounded plane or circular jets due to the vertically limited ambient fluid entrainment. In the second part of the paper, the effect of a lateral wall on the jet configuration is examined by placing it at different lateral distances from the jet outlet. The resulting velocity fields clearly show an inclined Coanda jet with details which seems to depend on the lateral wall distance itself. The analysis of self-similarity along the inclined jet direction reveals that for wall distances larger than 5 jet widths this dependence almost disappears.

  5. Thermodynamic analysis and experimental investigation of a Solo V161 Stirling cogeneration unit

    International Nuclear Information System (INIS)

    In order to investigate the Stirling engine implementation technology, a Solo Stirling Engine V161 cogeneration module has been installed at the Laboratory of Applied Thermodynamics of National Technical University of Athens. A special thermodynamic analysis of the engine's performance has been conducted introducing and utilizing specially designed computing codes along with the thermal balance study of the unit. Measurements were conducted under different operational conditions concerning various heat load stages of the engine, working pressure, as well as electric power production. Analysis of the experimental results has shown that the overall performance of the Stirling unit proved very promising and quite adequate for various areal applications, equally competing with other CHP systems. The performance of the unit experienced significant stability all over the operating range. The power stand ratio 0.35 differentiates Stirling cogeneration units from others that use diverging technologies significantly. The energy savings using a Stirling CHP unit, in respect to the concurrent use of a thermal and an electrical system at the same equivalent power has revealed 36.8%. -- Highlights: ? Thermodynamic analysis of an a-type Stirling engine. ? Development of generated electrical and thermal power of the m-CHP Solo Stirling Unit to engine's load comparison. ? Stirling m-CHP until heat balance analysis. ? Evaluation of the Solo Stirling V161 unit efficiency.

  6. Electronic Bandgap and Edge Reconstruction in Phosphorene: An Experimental/Theoretical joint investigation

    Science.gov (United States)

    Liang, Liangbo; Wang, Jun; Lin, Wenzhi; Sumpter, Bobby G.; Pan, Minghu; Meunier, Vincent

    2015-03-01

    Phosphorene, or monolayer black phosphorus, is a new 2D layered material with high hole mobility and direct semiconducting bandgap. However, the direct bandgap of phosphorene has not been directly measured, and the properties of its edges have not been considered in detail. In a joint experimental/theoretical work, we studied the electronic properties of phosphorene and its edges [Liang et al., Nano Letters, 2014, 14, 6400]. A detailed scanning tunneling microscopy/spectroscopy (STM/S) study with first-principles calculations reveals the presence of a semiconducting 2 eV gap, the direct bandgap for phosphorene. More importantly, we were able to identify a sharp mono-step in phosphorene that allowed us to perform the first-ever investigation of edges. STS measurements across the step edge indicate nontrivial multiple edge states located inside the 2 eV gap and below the Fermi level. To understand these edge states, we have modeled a series of 1D phosphorene nanoribbons including armchair- and zigzag-edged PNRs. Extensive density functional theory calculations show that edge reconstructions are responsible for energy positions of these edge states. The reconstructions self-passivate most edge dangling bonds by switching the coordination number of phosphorus from 3 to 4 or 5. NYSTAR Program C080117 and the Office of Naval Research; Oak Ridge National Laboratory by U.S. Department of Energy.

  7. Experimental and Numerical Investigation of Flow Properties of Supersonic Helium-Air Jets

    Science.gov (United States)

    Miller, Steven A. E.; Veltin, Jeremy

    2010-01-01

    Heated high speed subsonic and supersonic jets operating on- or off-design are a source of noise that is not yet fully understood. Helium-air mixtures can be used in the correct ratio to simulate the total temperature ratio of heated air jets and hence have the potential to provide inexpensive and reliable flow and acoustic measurements. This study presents a combination of flow measurements of helium-air high speed jets and numerical simulations of similar helium-air mixture and heated air jets. Jets issuing from axisymmetric convergent and convergent-divergent nozzles are investigated, and the results show very strong similarity with heated air jet measurements found in the literature. This demonstrates the validity of simulating heated high speed jets with helium-air in the laboratory, together with the excellent agreement obtained in the presented data between the numerical predictions and the experiments. The very close match between the numerical and experimental data also validates the frozen chemistry model used in the numerical simulation.

  8. Experimental Investigation of the Effectiveness of Various  Additives in Reducing Wind Erosion from Iron Ore Piles 

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Hassanvand

    2012-10-01

    Full Text Available Background and Objectives: Wind-induced particulate air pollution from iron ore piles can causes environmental and economic problems for steel industries. In this experimental study, the effectiveness of various additives in reducing particulate air pollution from iron ore piles was investigated in a laboratory wind tunnel.Materials and Methods:  The experimental set up consisted of a prismatic pile and a wind tunnel. Four different wind speeds of 4.3, 5, 7 and 11 m/s was used in the study  Municipal water, quick lime (2%, seawater, treated industrial wastewater and Polylatice (0.25% were used as additives to stabilize the upper layer of the pile. Results: Emission factors for non-stabilized (without additive piles at 4.3, 5, 7 and 11 m /s wind speeds were 46.7, 73.2, 1025.4 and 13768.7 g/m2, respectively. Stabilized piles with 2.6, 2.7, 2.8, 2.7 and 2.8 percent additive (moisture content of the upper layer of the pile for municipal water, Polylattice (0.25%, treated industrial wastewater, seawater and quick lime (2% indicated a decrease of 99.4%, 100%, 99.3%, 99.5% and 99.5% particulate emission reduction, respectively. Conclusions: Proper selection and use of additives on iron piles has the potential for decreasing  more than 99% of the wind-induced particulate emissions. Operational factors such as covered area, spray frequency, pile geometry, seasonal adjustments related to ambient temperature and humidity, wind speed and operator training need to be an integral part of the pollutant reduction program.              

  9. Experimental and computational investigation on low-dose radiation absorption in some living tissues

    International Nuclear Information System (INIS)

    The influence of low radiation doses on some types of living tissues was studied. Samples of animal tissues such as liver, brain, and bone placed on glass dishes were exposed to gamma radiation on a 137 Cs laboratory source with 3.14 MBq activity. To determine the irradiation times required to reach the absorbed doses we used in our experiment, the 137 Cs gamma radiation source, including the lead protection, was modeled using BEAMnrc Monte Carlo code. A phase space data file containing complete information (charge, energy, position, direction, history) on every particle leaving the simulated geometry was used as input in DOSRZnrc Monte Carlo code to calculate the Monte Cardose in cylindrical phantoms made of organic substitutes for the living tissues under investigation. We analyzed the depth doses and dose profiles obtained in these phantoms and estimated not only the irradiation times but also the sizes of the samples. Finally, the spectrophotometric assay of the average DNA and RNA content was carried out by standard biochemical methods. The experimental results revealed similar behaviors in the tissues with higher water content (liver and brain): a slight (logarithmic) increase in nucleic acid content was emphasized. The response of bone tissue (with the lowest water content) was also an increase that was fitted by an exponential function. The interpretation of these experimental data could be related to the stimulator effect of low radiatiod to the stimulator effect of low radiation doses (up to 11 mGy) on nucleic acid biosynthesis. The living cell adaptive reaction seemed to be higher in tissues with lower water content (bone), which could be associated with the reduced influence of water radicals (following radiolysis). (authors)

  10. Scientific investigation in deep boreholes at the Meuse/Haute Marne underground research laboratory, northeastern France

    International Nuclear Information System (INIS)

    From 1994 to 1996, the preliminary investigation carried out by Andra, identified a sector favourable for hosting a laboratory in argillaceous Callovo-Oxfordian formation which has a thickness of 130 m and lies more than 400 m below ground level. In November 1999 Andra began building an Underground Research Laboratory (URL) with a 3D seismic survey over 4 km2. From 2000 to 2004, large programs of boreholes were carried out on site and on the sector in order to define the characteristics of formations, to improve the regional geological and hydrogeological knowledge and to provide an accurate definition of structural features in Callovo-Oxfordian argillites and Dogger limestones. These drilling programs have provided a fine characterization of the argillites on the laboratory area and a good correlation of geological properties at a sector scale. (author)

  11. A laboratory technique for investigation of diffusion and transformation of volatile organic compounds in low permeability media

    Science.gov (United States)

    Gordon, Sue; Mackay, Doug; Górecki, Tadeusz; Cherry, John A.; Pawliszyn, Janusz

    2002-08-01

    A laboratory diffusion cell technique that permits spatial and temporal estimates of porewater concentrations over short intervals suitable for estimation of effective diffusion coefficients ( De) and degradation rate constants ( k) of volatile organic compounds (VOCs) in saturated low permeability media is presented. The diffusion cell is a sealed cylinder containing vapour reservoirs for sampling, including a vapour reservoir source and an array of vapour-filled "mini-boreholes", which are maintained water- and sediment-free by slightly negative porewater pressures. The vapour reservoirs were sampled by Solid Phase Micro-Extraction (SPME), resulting in minimal disturbance to the experimental system. Porewater concentrations are estimated from the measured vapour concentrations. Experiments were conducted using a non-reactive medium and five VOCs with a range in partitioning properties. Calibration experiments showed that equilibrium partition coefficients could be used for calculating concentrations in the vapour reservoir source from concentrations in the SPME coating after a 1-min microextraction and that the reservoir concentration was insignificantly affected by sampling. However, equilibrium was not reached during the one-min extraction of the boreholes; the microextraction reduced the borehole vapour concentrations, leading to diffusion of VOCs from porewater into the vapour-filled borehole. Thus, empirical partitioning coefficients were required for the determination of porewater VOC concentrations. The experimental data and numerical modelling indicate masses extracted by SPME extraction are relatively small, with minimal perturbation on processes studied in diffusion experiments. This technique shows promise for laboratory investigation of diffusion and transformation processes in low permeability media.

  12. A laboratory experimental setup for photo-absorption studies using synchrotron radiation

    CERN Document Server

    Shastri, A; Saraswati, P; Sunanda, K

    2002-01-01

    The photophysics beamline, which is being installed at the 450 MeV Synchrotron Radiation Source (SRS), Indus-l, is a medium resolution beamline useful for a variety of experiments in the VUV region viz. 500-2000 A. One of the major applications of this beamline is gas-phase photo-absorption studies. An experimental set up to be used for these experiments was designed, developed and tested in our laboratory. The setup consists of a high vacuum absorption cell, 1/4 m monochromator and detection system. For the purpose of testing, xenon and tungsten continuum sources were used and absorption spectra were recorded in the UV region. This setup was used to record the absorption spectrum of a few molecules like acetone, ammonia, benzene, formaldehyde and acetaldehyde in order to evaluate the performance of the experimental system which will subsequently be used with the photophysics beamline. Details of the design, fabrication and testing of the absorption cell and experimental procedures are presented in this repor...

  13. Infiltration on sloping surfaces: Laboratory experimental evidence and implications for infiltration modeling

    Science.gov (United States)

    Morbidelli, Renato; Saltalippi, Carla; Flammini, Alessia; Cifrodelli, Marco; Corradini, Corrado; Govindaraju, Rao S.

    2015-04-01

    Infiltration on sloping surfaces occupies an important role in our understanding of surface and subsurface hydrology. Previous studies have provided conflicting results about the role of slope on infiltration. Here, our main objective is to highlight, by well-controlled experiments, the slope role in the absence of the conflicting contributions generated by other physical processes observed in previous studies under natural or laboratory conditions. The experimental program was designed to resolve some of the confounding factors such as lower impermeable boundary condition, range of rainfall rates relative to soil saturated hydraulic conductivity, surface sealing, and erosion of top soil. The experimental apparatus consists of a box containing a natural bare soil with slope angle ? chosen between 0° and 10°, two sensors of surface and deep flow, one probe for moisture content and an artificial rainfall generator. The primary experimental results suggest that under steady conditions and rainfall rate, r, greater than saturated hydraulic conductivity, Ks, the deep flow, Qd, decreases with increasing slope angle, ?, up to a value leading to Qd(? = 1°)/Qd(? = 10°) equal to ?4 which is in contrast with the results provided in a few earlier papers. Furthermore, in sloping bare soils surface runoff is produced even for r < Ks. Finally, we discuss the link between Qd(?) and the shear stress at the soil surface as a guideline in the determination of an effective saturated hydraulic conductivity to be incorporated in the existing horizontal infiltration models.

  14. Behavioral investigation of mice with experimental autoimmune encephalomyelitis / Investigação comportamental de camundongos com encefalomielite autoimune experimental

    Scientific Electronic Library Online (English)

    David Henrique, Rodrigues; Márcia de Carvalho, Vilela; Norinne, Lacerda-Queiroz; Aline Silva de, Miranda; Larissa Fonseca da Cunha, Sousa; Helton José dos, Reis; Antônio Lúcio, Teixeira.

    2011-12-01

    Full Text Available Esclerose múltipla é uma doença neuroinflamatória que resulta em séria incapacidade neurológica. Além do comprometimento físico, sintomas comportamentais também são comuns em pacientes com esclerose múltipla. A encefalomielite autoimune experimental (EAE) é considerada um modelo de esclerose múltipl [...] a e mimetiza as principais caracte-rísticas da doença, como a desmielinização e a fraqueza motora. Neste trabalho, objetivamos estudar parâmetros comportamentais em animais com EAE usando o modelo de MOG35-55 em camundongos C57BL/6. Analisamos memória e ansiedade em animais utilizando o labirinto em cruz elevado, o teste da esquiva inibitória e o teste de memória de reconhecimento. Nenhuma diferença em quaisquer dos testes foi encontrada comparando animais controles e animais induzidos com EAE. Assim, concluímos que alterações comportamentais em animais com EAE induzidos com MOG35-55 são provavelmente sutis ou ausentes. Abstract in english Multiple sclerosis is a neuroinflammatory disease that results in serious neurological disability. Besides physical impairment, behavioral symptoms are also common in patients with multiple sclerosis. Experimental autoimmune encephalomyelitis (EAE) is considered to be a model of multiple sclerosis a [...] nd mimics the main features of the disease, such as demyelination and motor impairment. In this work, we aimed to study behavioral parameters in animals with EAE using the MOG35-55 model in C57BL/6 mice. We analyzed memory and anxiety in animals using the elevated plus maze, the step down inhibitory avoidance task and the memory recognition test. No differences in any tests were found when comparing controls and animals induced with EAE. Therefore, we conclude that behavioral changes in animals with EAE induced with MOG35-55 are probably subtle or absent.

  15. Experimental investigation on the yield behavior of Nomex honeycombs under combined shear-compression

    Scientific Electronic Library Online (English)

    Zhiwei, Zhou; Zhihua, Wang; Longmao, Zhao; Xuefeng, Shu.

    2012-08-01

    Full Text Available This paper presents an experimental investigation on the yield behavior of Nomex honeycombs under combined shearcompression with regard to out-of-plane direction. Four different types of specimens were designed in order to investigate the influence of in-plane orientation angle on the yield behavior [...] of honeycombs under combined loads. Two different failure modes of honeycomb specimens, i.e. the plastic buckling and the extension fracture of cell walls, are observed under combined shear-compression. The experimental results validate that the in-plane orientation angle has a significant influence on the developments of the experimental yield surface. The experimental yield surfaces are compared with a phenomenological yield criterion capable of accounting for anisotropic behavior. The comparative analytical results indicate the experimental yield surfaces are approximately consistent with the theoretical yield surfaces in the normal-shear stress space. These experimental results are useful to develop constitutive models of Nomex honeycombs under combined shear-compression.

  16. Geoscientific Research Program of Mizunami Underground Research Laboratory. Study plan of surface-based investigation phase

    International Nuclear Information System (INIS)

    The Power Reactor and Nuclear Fuel Development Corporation (PNC) plans to construct the Mizunami Underground Research Laboratory (MIU), in order to promote scientific studies of the deep geological environment (the Geoscientific Research Program), with a view of providing a sound basis for research and development programs regarding geological disposal projects. The MIU project can be divided into three phases: Before, during and after the construction of the laboratory. In this paper, the research plan of the first phase (surface-based investigations) will be mainly described. In this phase, the following items will be investigated from the ground surface: Geological structures and flow field/characteristics of the groundwater, etc. in the MIU site. Based on the these survey results, the prediction of the deep geological environment will be carried out, and the specific research items after the first phase and the design of underground facilities will be established. (author)

  17. Micro black holes in the laboratory and other experimental signatures of quantum gravity

    International Nuclear Information System (INIS)

    We investigate the possibility of quantum gravity effects setting in at much lower energies than the Planck scale. In particular, we study the formation and detection of microscopic black holes at the LHC as well as precision measurements of the gyroscopic moment of the muon and neutrino oscillations. We find that quantum gravity effects lead to observable signatures both in high energy and high precision scenarios. Comparison with experimental data allows us to constrain the parameters of the models. (author)

  18. Experimental and numerical investigation of an air to air supersonic ejector for propulsion of a small supersonic wind tunnel

    Science.gov (United States)

    Kracík, Jan; Dvo?ák, Václav

    2015-05-01

    The article deals with experimental and numerical investigation of an air to air supersonic ejector with twelve primary nozzles. The ejector is supposed to be used for propulsion of a small experimental supersonic wind tunnel which is situated in laboratories of Technical University of Liberec. A novel arrangement with 12 primary nozzles is used. The nozzles are placed at the periphery of the mixing chamber. The secondary stream enters the ejector through the free centre of the mixing chamber and is sucked into the space between the primary nozzles. Moreover the declination of the primary nozzles towards to ejector axis is 8.2° and the shape of the mixing chamber and diffuser walls is given by normal cubic spline function, which was investigated in previous work. The declination of the primary nozzles is supposed to eliminate reversal flow in the centre of the mixing chamber. Experimental results for different numbers of simultaneously activated primary nozzles are carried out. Experimental results are compared to the numerical simulation made with the help of Ansys Fluent software.

  19. Experimental and numerical investigation of an air to air supersonic ejector for propulsion of a small supersonic wind tunnel

    Directory of Open Access Journals (Sweden)

    Kracík Jan

    2015-01-01

    Full Text Available The article deals with experimental and numerical investigation of an air to air supersonic ejector with twelve primary nozzles. The ejector is supposed to be used for propulsion of a small experimental supersonic wind tunnel which is situated in laboratories of Technical University of Liberec. A novel arrangement with 12 primary nozzles is used. The nozzles are placed at the periphery of the mixing chamber. The secondary stream enters the ejector through the free centre of the mixing chamber and is sucked into the space between the primary nozzles. Moreover the declination of the primary nozzles towards to ejector axis is 8.2° and the shape of the mixing chamber and diffuser walls is given by normal cubic spline function, which was investigated in previous work. The declination of the primary nozzles is supposed to eliminate reversal flow in the centre of the mixing chamber. Experimental results for different numbers of simultaneously activated primary nozzles are carried out. Experimental results are compared to the numerical simulation made with the help of Ansys Fluent software.

  20. Experimental and Numerical Investigation of Desalination Plant Outfalls in Limited Disposal Areas

    OpenAIRE

    Abou-elhaggag, Mohamed E.; El-gamal, Mohamed H.; Farouk, Mohamed I.

    2011-01-01

    In this study, experimental and numerical investigations of the dense brine jets are conducted for disposal areas of limited extent. First, a new experimental model representing a section of sea floor with a single port brine outfall is built to study different characteristics of dense jets. Second, a number of numerical experiments have been conducted via Fluent CFD package to compare the numerical results with its corresponding physical observations and measurements. Experimental observatio...

  1. The influence of wages on public officials' corruptibility: A laboratory investigation

    OpenAIRE

    Veldhuizen, Roel

    2013-01-01

    Previous studies have proposed a link between corruption and wages in the public sector. The present paper investigates this link using a laboratory experiment. In the experiment, public officials have the opportunity to accept a bribe and can then decide between a neutral and a corrupt action. The corrupt action benefits the briber but poses a large negative externality on a charity. The results show that increasing public officials' wages greatly reduces their corruptibility. In particular,...

  2. The physics and chemistry of dusty plasmas: A laboratory and theoretical investigation

    Science.gov (United States)

    Whipple, E. C.

    1986-01-01

    Theoretical work on dusty plasmas was conducted in three areas: collective effects in a dusty plasma, the role of dusty plasmas in cometary atmospheres, and the role of dusty plasmas in planetary atmospheres (particularly in the ring systems of the giant planets). Laboratory investigations consisted of studies of dust/plasma interactions and stimulated molecular excitation and infrared emission by charged dust grains. Also included is a list of current publications.

  3. Experimental investigation and comparison of different equalizers for four level pulse amplitude modulation

    DEFF Research Database (Denmark)

    Eiselt, Nicklas; Griesser, Helmut

    2015-01-01

    Numerical and experimental investigations are undertaken to analyze and compare the performance of different equalizers for four-level pulse amplitude modulation, which is considered a promising candidate for the next generation of data center interconnects.

  4. Results from experimental investigations of the performance of air condensers for steam turbine units

    Science.gov (United States)

    Fedorov, V. A.; Mil'man, O. O.; Kolesnikov, N. V.; Anan'ev, P. A.; Dunaev, S. N.; Mikhal'kov, A. M.; Mosin, A. V.; Kondrat'ev, A. V.

    2013-02-01

    Results from experimental investigations of the model versions of Type ABC GI air condensers are presented, and it is shown that these condensers have better performance characteristics as compared with their analogs that are currently in operation.

  5. Laboratory investigations of stable carbon and oxygen isotope ratio data enhance monitoring of CO2 underground

    Science.gov (United States)

    Barth, Johannes A. C.; Myrttinen, Anssi; Becker, Veith; Nowak, Martin; Mayer, Bernhard

    2014-05-01

    Stable carbon and oxygen isotope data play an important role in monitoring CO2 in the subsurface, for instance during carbon capture and storage (CCS). This includes monitoring of supercritical and gaseous CO2 movement and reactions under reservoir conditions and detection of potential CO2 leakage scenarios. However, in many cases isotope data from field campaigns are either limited due to complex sample retrieval or require verification under controlled boundary conditions. Moreover, experimentally verified isotope fractionation factors are also accurately known only for temperatures and pressures lower than commonly found in CO2 reservoirs (Myrttinen et al., 2012). For this reason, several experimental series were conducted in order to investigate effects of elevated pressures, temperatures and salinities on stable carbon and oxygen isotope changes of CO2 and water. These tests were conducted with a heateable pressure device and with glass or metal gas containers in which CO2 reacted with fluids for time periods of hours to several weeks. The obtained results revealed systematic differences in 13C/12C-distributions between CO2 and the most important dissolved inorganic carbon (DIC) species under reservoir conditions (CO2(aq), H2CO3 and HCO3-). Since direct measurements of the pH, even immediately after sampling, were unreliable due to rapid CO2 de-gassing, one of the key results of this work is that carbon isotope fractionation data between DIC and CO2 may serve to reconstruct in situ pH values. pH values reconstructed with this approach ranged between 5.5 and 7.4 for experiments with 60 bars and up to 120 °C and were on average 1.4 pH units lower than those measured with standard pH electrodes directly after sampling. In addition, pressure and temperature experiments with H2O and CO2 revealed that differences between the oxygen isotope ratios of both phases depended on temperature, water-gas ratios as well as salt contents of the solutions involved. Such systematic knowledge of the extent of oxygen isotope fractionation between H2O and CO2 can help to reconstruct equilibration times, fluid-CO2 ratios as well as temperature and salinity conditions. Isotope results from systematic laboratory studies and the information they provide for assessing in situ reservoir conditions can be transferred to field applications concerning integrity of CO2 reservoirs. They can also apply to natural systems and other industrial uses that involve monitoring of gases in the subsurface under similar pressure and temperature conditions. Reference: Myrttinen, A., Becker, V., Barth, J.A.C., 2012. A review of methods used for equilibrium isotope fractionation investigations between dissolved inorganic carbon and CO2. Earth-Science Reviews, 115(3): 192-199.

  6. Flow cytometric investigation on degradation of macro-DNA by common laboratory manipulations

    Directory of Open Access Journals (Sweden)

    Sang-Ryoul Park

    2011-05-01

    Full Text Available The degree and characteristics of physical degradation of macro-DNA molecules by common laboratory manipulations are reported. With linearized lambda-phage viral DNA as the model DNA, fragmentation of macro-DNA by various indispensable laboratory manipulations were investigated using a high sensitivity flow cytometric setup. Investigated manipulations included pipetting, vortexing, rocking, freeze-thawing, ultrasonication and ultrafiltration. “Exhaustive counting” of the intact lambda DNA molecules following such manipulations enabled a quantitative assessment of the resulting fragmentation, which also revealed the type of degradation reflected in the fragmentation patterns. The use of high sensitivity flow cytometry was especially suited to investigate the degradation of dilute DNA solutions that may not be suitable for analysis using traditional methods. Notable findings of this study included: the boarderline-size of DNA chains in terms of susceptibility to shear stresses by such manipulations; discernable instability of nicked DNAs; shattering-fragmentation of DNAs by freeze-thawing or ultrasonication; effectiveness of some protection media; marked “self-protection effect” of concentrated DNA solutions. These findings support and refine our traditional knowledge on how to maintain the physical integrity of macro-DNA molecules against inevitable laboratory manipulations.

  7. RCRA Facility Investigation report for Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    This report presents data and information related to remedial investigation studies for Oak Ridge National Laboratory (ORNL). Information is included on a soil gas survey, surface radiological investigations of waste areas, and well installation for ground water monitoring

  8. Experimental Study of Drag Resistance using a Laboratory Scale Rotary Set-Up

    DEFF Research Database (Denmark)

    Weinell, Claus Erik; Olsen, Kenneth N.

    2003-01-01

    This work covers an experimental study of the drag resistance of different painted surfaces and simulated large-scale irregularities, viz. dry spraying, weld seams, barnacle fouling and paint remains. A laboratory scale rotary set-up was used to determine the drag resistance, and the surface roughness of the samples was determined by means of two different stylus-based methods, one having a 1.6 mm ball stylus (giving the macro-roughness) and the other having a needle type stylus (giving the micro-roughness). It is demonstrated that, in the case of ideal painted surfaces (low macro-roughness), the micro-roughness is much more important than the macro-roughness. On the other hand, the study also indicates that larger scale irregularities have a much greater influence on the drag resistance compared to measurements of the paint system alone.

  9. Project plan for the decontamination and decommissioning of the Argonne National Laboratory Experimental Boiling Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Boing, L.E.

    1989-12-01

    In 1956, the Experimental Boiling Water Reactor (EBWR) Facility was first operated at Argonne National Laboratory (ANL) as a test reactor to demonstrate the feasibility of operating an integrated power plant using a direct cycle boiling water reactor as a heat source. In 1967, ANL permanently shut down the EBWR and placed it in dry lay-up. This project plan presents the schedule and organization for the decontamination and decommissioning of the EBWR Facility which will allow it to be reused by other ANL scientific research programs. The project total estimated cost is $14.3M and is projected to generate 22,000 cubic feet of low-level radioactive waste which will be disposed of at an approved DOE burial ground. 18 figs., 3 tabs.

  10. Investigating student learning in upper-division laboratory courses on analog electronics

    Science.gov (United States)

    Stetzer, Mackenzie

    2015-03-01

    There are many important learning goals associated with upper-division laboratory instruction; however, until recently, relatively little work has focused on assessing the impact of these laboratory-based courses on students. As part of an ongoing, in-depth investigation of student learning in upper-division laboratory courses on analog electronics, we have been examining the extent to which students enrolled in these courses develop a robust and functional understanding of both canonical electronics topics (e.g., diode, transistor, and op-amp circuits) and foundational circuits concepts (e.g., Kirchhoff's laws and voltage division). This focus on conceptual understanding is motivated in part by a large body of research revealing significant student difficulties with simple dc circuits at the introductory level and by expectations that students finish electronics courses with a level of understanding suitable for building common, practical circuits in a real-world environment. Recently, we have extended the scope of our investigation to include more laboratory-focused learning goals such as the development of (1) troubleshooting proficiency and (2) circuit chunking and design abilities. In this talk, I will highlight findings from written questions and interview tasks that have been designed to probe student understanding in sufficient depth to identify conceptual and reasoning difficulties. I will also use specific examples to illustrate the ways in which this research may inform instruction in upper-division laboratory courses on analog electronics. This work has been supported in part by the National Science Foundation under Grant Nos. DUE-1323426, DUE-1022449, DUE-0962805, and DUE-0618185.

  11. An easy-to-build remote laboratory with data transfer using the Internet School Experimental System

    International Nuclear Information System (INIS)

    The present state of information communication technology makes it possible to devise and run computer-based e-laboratories accessible to any user with a connection to the Internet, equipped with very simple technical means and making full use of web services. Thus, the way is open for a new strategy of physics education with strongly global features, based on experiment and experimentation. We name this strategy integrated e-learning, and remote experiments across the Internet are the foundation for this strategy. We present both pedagogical and technical reasoning for the remote experiments and outline a simple system based on a server-client approach, and on web services and Java applets. We give here an outline of the prospective remote laboratory system with data transfer using the Internet School Experimental System (ISES) as hardware and ISES WEB Control kit as software. This approach enables the simple construction of remote experiments without building any hardware and virtually no programming, using a paste and copy approach with typical prebuilt blocks such as a camera view, controls, graphs, displays, etc. We have set up and operate at present seven experiments, running round the clock, with more than 12 000 connections since 2005. The experiments are widely used in practical teaching of both university and secondary level physics. The recording of the detailed steps the experimentor takes during the measurement enables detailed study of the psychological ables detailed study of the psychological aspects of running the experiments. The system is ready for a network of universities to start covering the basic set of physics experiments. In conclusion we summarize the results achieved and experiences of using remote experiments built on the ISES hardware system

  12. An easy-to-build remote laboratory with data transfer using the Internet School Experimental System

    Science.gov (United States)

    Schauer, František; Lustig, František; Dvo?ák, Ji?í; Ožvoldová, Miroslava

    2008-07-01

    The present state of information communication technology makes it possible to devise and run computer-based e-laboratories accessible to any user with a connection to the Internet, equipped with very simple technical means and making full use of web services. Thus, the way is open for a new strategy of physics education with strongly global features, based on experiment and experimentation. We name this strategy integrated e-learning, and remote experiments across the Internet are the foundation for this strategy. We present both pedagogical and technical reasoning for the remote experiments and outline a simple system based on a server-client approach, and on web services and Java applets. We give here an outline of the prospective remote laboratory system with data transfer using the Internet School Experimental System (ISES) as hardware and ISES WEB Control kit as software. This approach enables the simple construction of remote experiments without building any hardware and virtually no programming, using a paste and copy approach with typical prebuilt blocks such as a camera view, controls, graphs, displays, etc. We have set up and operate at present seven experiments, running round the clock, with more than 12 000 connections since 2005. The experiments are widely used in practical teaching of both university and secondary level physics. The recording of the detailed steps the experimentor takes during the measurement enables detailed study of the psychological aspects of running the experiments. The system is ready for a network of universities to start covering the basic set of physics experiments. In conclusion we summarize the results achieved and experiences of using remote experiments built on the ISES hardware system.

  13. Application of Results of Experimental Identification in Control of Laboratory Helicopter Model

    Directory of Open Access Journals (Sweden)

    Kamil Dolinsky

    2011-01-01

    Full Text Available This article deals with experimental identification and control of laboratory helicopter model CE 150 manufactured by company Humusoft. Structure of the identified system was approximated by linear black-box models. Discrete Input/Output Auto-Regressive Moving Average model with eXternal input (ARMAX and its state space equivalent were used. Parameters of the models were estimated by regression techniques using System Identification Toolbox for Matlab. Acquired models were validated using simulations, residual analysis and real-time control. Input/output data necessary for identification were obtained by measurements from laboratory model and were processed using Real-Time Toolbox for Matlab. Based on acquired mathematical models input/output and state space controllers were designed (input/output pole placement with integration, state space pole placement with integration and observer. Designed controllers were implemented in Matlab environment using the Real Time Toolbox and their performance was verified by real-time control of the helicopter model.

  14. A State-of-the-Art Experimental Laboratory for Cloud and Cloud-Aerosol Interaction Research

    Science.gov (United States)

    Fremaux, Charles M.; Bushnell, Dennis M.

    2011-01-01

    The state of the art for predicting climate changes due to increasing greenhouse gasses in the atmosphere with high accuracy is problematic. Confidence intervals on current long-term predictions (on the order of 100 years) are so large that the ability to make informed decisions with regard to optimum strategies for mitigating both the causes of climate change and its effects is in doubt. There is ample evidence in the literature that large sources of uncertainty in current climate models are various aerosol effects. One approach to furthering discovery as well as modeling, and verification and validation (V&V) for cloud-aerosol interactions is use of a large "cloud chamber" in a complimentary role to in-situ and remote sensing measurement approaches. Reproducing all of the complex interactions is not feasible, but it is suggested that the physics of certain key processes can be established in a laboratory setting so that relevant fluid-dynamic and cloud-aerosol phenomena can be experimentally simulated and studied in a controlled environment. This report presents a high-level argument for significantly improved laboratory capability, and is meant to serve as a starting point for stimulating discussion within the climate science and other interested communities.

  15. Mathematical and experimental investigation of heat control and power increase in air-cooled aircraft engines

    Science.gov (United States)

    Gosslau, F

    1929-01-01

    In order to understand the numerical relations between the air velocity, temperature of the cylinder walls, heat dissipation, cylinder dimensions and type of construction an experimental plant was installed in the Siemens and Halske laboratory. The experimental cylinder was exposed to the air stream of a wind tunnel. The compression chamber was heated by an electrically heated oil bath kept constantly in motion by a stirrer. The wall temperatures were measured by thermocouples. The air stream was produced a seven-watt blower. The air flowed through a current rectifier (honeycomb), diffuser, air chamber with quieting sieves and a nozzle.

  16. Numerical and experimental investigation of swirling flow in a conical diffuser

    Directory of Open Access Journals (Sweden)

    David Štefan

    2015-01-01

    Full Text Available The decelerated swirling flow often breaks down into helical structure which is unstable and causes unsteady velocity and pressure fields. The numerical and experimental investigation of this flow pattern is carried out on the experimental apparatus consisting of the swirl generator (producing a strong swirling flow and the transparent conical diffuser (where the helical structure can be observed. The open source CFD software OpenFOAM employing realizable k-epsilon turbulence model is used for the numerical simulations. The experimental measurements are focused on LDA measurements of velocity profiles in the diffuser cross-sections. Agreements between numerical end experimental results are discussed.

  17. Development, integrated investigation, laboratory and in-flight testing of Chibis-M microsatellite ADCS

    Science.gov (United States)

    Ovchinnikov, M. Yu.; Ivanov, D. S.; Ivlev, N. A.; Karpenko, S. O.; Roldugin, D. S.; Tkachev, S. S.

    2014-01-01

    Design, analytical investigation, laboratory and in-flight testing of the attitude determination and control system (ADCS) of a microsatellites are considered. The system consists of three pairs of reaction wheels, three magnetorquers, a set of Sun sensors, a three-axis magnetometer and a control unit. The ADCS is designed for a small 10-50 kg LEO satellite. System development is accomplished in several steps: satellite dynamics preliminary study using asymptotical and numerical techniques, hardware and software design, laboratory testing of each actuator and sensor and the whole ADCS. Laboratory verification is carried out on the specially designed test-bench. In-flight ADCS exploitation results onboard the Russian microsatellite "Chibis-M" are presented. The satellite was developed, designed and manufactured by the Institute of Space Research of RAS. "Chibis-M" was launched by the "Progress-13M" cargo vehicle on January 25, 2012 after undocking from the International Space Station (ISS). This paper assess both the satellite and the ADCS mock-up dynamics. Analytical, numerical and laboratory study results are in good correspondence with in-flight data.

  18. Experimental investigations of the fracture toughness enhancement associated with shallow flaws

    International Nuclear Information System (INIS)

    The Heavy Section Steel Technology Program (HSST) is investigating the influence of flaw depth on the fracture toughness of reactor pressure vessel (RPV) steel. Recently, it has been shown that shallow cracks tend to exhibit an elevated toughness as a result of a loss of constraint at the crack tip. The loss of constraint takes place when interaction occurs between the elastic-plastic crack-tip stress field and the specimen surface nearest the crack tip. An increased shallow-crack fracture toughness is of interest to the nuclear industry because probabilistic fracture-mechanics evaluations show that shallow flaws play a dominant role in the probability of vessel failure during postulated pressurized-thermal-shock (PTS) conditions. The HSST investigation is a joint analytical/experimental study combining the use of shallow-cracked laboratory specimens with RPV analysis. All tests have been performed on beam specimens loaded in 3-point bending using specimens about 100 mm deep. Primarily two crack depths have been considered: a = 50 and 9 mm (a/W = 0.5 and 0.1). Test results indicate a significant increase in the fracture toughness associated with the shallow flaw specimens in the lower transition region compared to the conventional fracture toughness. The testing has produced a limited database of fracture-toughness values as a function of crack depth which can be used in probabilistic or deterministic fracture mechanics analyses of pressure vessel integrity. Final teses of pressure vessel integrity. Final test results from the shallow-crack fracture toughness program will be included in this paper. Examination of previously tested thermal shock data reveals that no toughness elevation appears to be present even though the thermal shock cylinders were tested with shallow flaws. Results from the HSST shallow-crack fracture toughness program to date can be summarized as follows: 1) Thirty-eight relatively large laboratory beam specimens were tested to compare the behavior of specimens with shallow-flaws to that of specimens with deep flaws. 2) The results showed conclusively that A 533 B shallow-flaw beam specimens have a significant increase in CTOD or Jc toughness and KJc toughness in the transition region. All specimens were approximately 100 mm deep (W). Shallow-crack beams had crack depths ranging from 9-14 mm (a/W - 0.1 to 0.14), while deep-crack beams had 50 mm deep cracks (a/W - 0.5). 3) There is little or no difference in toughness on the lower shelf where linear-elastic conditions exist for specimens with either deep or shallow flaws. 4) Varying the beam thickness from 50 to 150 mm had little or no influence on the toughness in both the shallow- and deep-crack specimens in spite of the fact that the ASTM E-399 requirement for valid plane-strain results were not met. 5) In the transition region, the increase in shallow-flaw toughness compared with deep-flaw results appears to be well characterized by a temperature shift of 35 deg. C (63 deg. F). 6) Post-test two-dimensional plane-strain analyses were performed on both shallow-flaw and deep-flaw specimens. The analytical J-integral results were consistent with experimental J-integral results confirming the validity of the J-estimation schemes used and the effect of flaw depth on fracture toughness. 7) Previous HSST thermal-shock data failed to show any substantial toughness increase in spite of the fact that the tests were conducted on large, unclad cylindrical vessels with a shallow, initial flaw. There is no reason to believe that the thermal-shock cylinders would not have shown a toughness elevation if the cylinders had been subjected to the same loading conditions as the shallow-crack beams, namely, no biaxial stress

  19. Investigation of analytical and experimental behavior of nuclear facility ventilation systems

    International Nuclear Information System (INIS)

    The behavior of nuclear facility ventilation systems subjected to both natural and man-caused accidents is being investigated. The purpose of the paper is to present a program overview and highlight recent results of the investigations. The program includes both analytical and experimental investigations. Computer codes for predicting accident-induced gas dynamics and test facilities to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. A unique test facility and recently obtained structural limits for high efficiency particulate air filters are reported

  20. Experimental and numerical investigation of the effect of basaltic dykes on transient saltwater intrusion

    Science.gov (United States)

    Abdoulhalik, Antoifi; Ahmed, Ashraf; Hamill, Gerrard

    2015-04-01

    Heterogeneity in porous media is one of the major factors that control mixing zone and saltwater wedge dynamics. Basaltic dykes are natural geological structures that can significantly affect groundwater flow and solute transport in coastal aquifers. Few recent studies have investigated the effects of heterogeneity on the freshwater-saltwater mixing zone. However, most of these studies have focused on steady-state conditions. Furthermore, as per our knowledge no one has so far completed experiments to study the impact of basaltic dykes on transient saltwater intrusion. In this study, we have performed experiments in a laboratory-scale aquifer model to study saltwater intrusion process under different heterogeneous settings; a dyke was set at different locations and several values of thickness and permeability were tested. Using a variable-head groundwater system, a head difference was imposed across the porous media and images of the transient saltwater-wedge were recorded at thirty second intervals. The experimental data sets were simulated using the MODFLOW-family variable density flow code SEAWAT. The results show that under intruding-wedge conditions, the width of the mixing zone is almost two orders of magnitude larger in the presence of the dyke than it is in the homogeneous case, while it is more than ten times larger under receding-wedge conditions. A slight increase of the toe length was observed (around nine percent) in the presence of the dyke under intruding-wedge and receding-wedge conditions. When the permeability of the dyke is further reduced, it acts as an impervious barrier that almost prevents the progression of the saltwater wedge. Thus, saltwater is accumulated along the side boundary, and then forced to drain along the bottom boundary. The results highlight the significant effects of macroscopic variations in aquifer properties (such as volcanic dykes) in the temporal evolution of mixing zone dynamics (widening and narrowing) and the production preferential flow paths which can lead to an increase of the toe length.

  1. Horonobe underground research laboratory project investigation program for the 2006 fiscal year

    International Nuclear Information System (INIS)

    As part of the research and development program on geological disposal of high-level radioactive waste (HLW), the Horonobe Underground Research Center, a division of the Japan Atomic Energy Agency (JAEA), is implementing the Horonobe Underground Research Laboratory Project (Horonobe URL Project) with the aim of investigating sedimentary rock formations. According to the research plan described in the Midterm Plan of JAEA, geological investigations are to be carried out during the drilling of a shaft down to intermediate depth, while research and development in the areas of engineering technology and safety assessment are to be promoted by collaboration with other research organizations. The results of the R and D activities will be systematized as a 'knowledge base' that supports a wide range of arguments related to the safety of geological disposal. The Horonobe URL Project 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 investigation program for the 2006 fiscal year (2006/2007), the second year of the Phase 2 investigations. The investigations in the 2006 fiscal year are focused on the Hokushin area of Horonobe, which was selected as the area for URL construction. The main investigation region extends over approximately 3km x 3km. Construction of the underground facilities, which was initiated in the 2005 fiscal year, is ongoing and Phase 2 investigations are underway. A progress report on the surface-based investigations (Phase 1) is also being prepared. Regarding the surface facilities, construction of the Research and Administration Facility and the Test Facility will be completed in May 2006. Construction of the Public Information House is still continuing and preparation of the exhibits has started. A preliminary design will be drawn up for the International Communication House. (author)

  2. Current status of phase II investigations, Mizunami Underground Research Laboratory (MIU) project - 16262

    International Nuclear Information System (INIS)

    The Mizunami Underground Research Laboratory (MIU) Project, a comprehensive research project investigating the deep underground environment in crystalline rock, is being conducted by the Japan Atomic Energy Agency at Mizunami City, Central Japan. The MIU Project is being carried out in three overlapping phases: Surface-based Investigation (Phase I), Construction (Phase II), and Operation (Phase III), with a total duration of 20 years. The overall project goals of the MIU Project from Phase I through to Phase III are: 1) to establish techniques for investigation, analysis and assessment of the deep geological environment, and 2) to develop a range of engineering techniques for deep underground application. Phase I was completed in March 2004, and Phase II investigations associated with the construction of the underground facilities are currently underway. Phase II investigation goals are to evaluate the geological, hydrogeological, hydrogeochemical and rock mechanical models developed in Phase I and to assess changes in the deep geological environment caused by the construction of underground facilities. Geological mapping, borehole investigations for geological, hydrogeological, hydrochemical and rock mechanical studies are being carried out in shafts and research galleries in order to evaluate the models. Long-term monitoring of changes in groundwater chemistry and pressure associated with the construction of the underground facilities continue in and around the MIU facilities continue in and around the MIU site, using existing boreholes and monitoring systems. This report summarizes the current status of the MIU Project on results of the Phase II investigations to date. (authors)

  3. Initial experimental results from the Laboratory Biosphere closed ecological system facility

    Science.gov (United States)

    Alling, A.; Allen, J.; Dempster, W.; Nelson, M.; Silverstone, S.; van Thillo, M.

    Results from the closure and initial closed ecological system research in the "Laboratory Biosphere" facility in Santa Fe, New Mexico (USA) will be presented. The facility was initially sealed in April 2002; and the first crop experiments with soybeans commenced in May 2002. The Laboratory Biosphere was created by the team which invented, built and operated Biosphere 2 during its years of closed ecological system functioning (1991-94) and is a testbed to build upon the lessons learned. It is an opportunity to continue experiments with a sustainable soil based agriculture system unlike most bioregenerative systems which use hydroponic systems dependent on a supply of nutrient solution. Because of the small volume of the system (34-45 m3), developing mechanisms to keep parameters like carbon dioxide within acceptable limits will be critical. Recycle of nutrients within the system to maintain soil fertility; and the ability of the inherent complex ecology of soils and a soil bed reactor to handle trace gas buildups are primary research goals. Other research goals are determination of short and long-term exchanges between soil, plants and atmosphere, especially for carbon dioxide, oxygen, nitrogen, NOX, and methane, impact of cultivation (tillage) on soil/atmospheric exchanges., investigation and development of strategies to return nutrients to the soil to maintain fertility, e.g. shredding biomass vs. composting, impact on soil chemistry of returning leachate water to the soil as irrigation water. The microbiological status of soils prior to experiments and over time will allow measurement of changes in microbial diversity and the determination of the role of soil microbes in biogeochemical cycles. Integration of automated sensor and control in the system with real-time modeling has importance for operation, research and educational outreach programs. The Laboratory Biosphere is intended to test and develop a "cybersphere" (network of shared intelligence) that may be scaled up for natural ecosystems and the global environment.

  4. Horonobe Underground Research Laboratory Project. Plans for surface-based investigations. Phase 1

    International Nuclear Information System (INIS)

    The Horonobe Underground Research Laboratory Project is an investigation project which is planned over 20 years. The investigations are conducted in the three phases: investigations from surface (Phase 1), investigations during construction of the underground facility (Phase 2) and investigations using the facility (Phase 3). Taking into account the results from 'H12: Project of Establish the Scientific and Technical Basis for HLW Disposal in Japan - Second Progress Report on Research and Development for the Geological Disposal of HLW in Japan-' (JNC, 2000), research and development goals for the Horonobe URL project were re-defined as follows; a) Development of investigation technologies for the geological environment, b) Development of monitoring technologies for the geological environment, c) Study on the long-term stability of the geological environment, d) Development of the basis for engineering technologies in deep underground, e) Verification of technologies for engineered barriers, f) Development of detailed designing technologies of the repositories, and g) Improvement of safety assessment methodologies. Investigations for the goals a) to d) and e) to g) are conducted in the 'Geoscientific Research' and 'Research and Development on Geological Disposal', respectively. In Phase 1, a 'laboratory construction area' of a few kilometers square is selected based on the results from early stage investigations. Subsequent investigations are concentrated in the selectestigations are concentrated in the selected area and its periphery. Acquisition of data by surface-based investigations, modeling of the geological environment and predictions of changes in the geological environment caused by the construction of the underground facility, are conducted in a) Development of investigation technologies for the geological environment. Development and installation of monitoring equipments and data acquisition prior to the construction of the underground facility fall under b) Development of monitoring technologies for the geological environment. Information on earthquake/fault activities, uplift/subsidence/denudation processes and crustal activities are collected and integrated by literature survey, surface geological investigations and earthquake monitoring in c) Study on the long-term stability of the geological environment. Designing of the underground facility, examination of construction management methods, and investigation plans for restoration techniques on damages of the construction are focussed in d) Development of the basis for engineering technologies in deep underground. Investigation plans for Phases 2 and 3 include e) Demonstration of technologies for engineered barrier and f) Development of methodologies for detailed designing of deep repositories. Safety assessment models are tested and improved, and items, amount and accuracy of data for safety assessment are confirmed through investigations for g) Improvement of reliability on safety assessment methods. Environmental survey in the laboratory construction area, and designing and land development for ground facilities are conducted in Phase 1. A part of the research and development for the 'Earthquake Frontier Research Project' is also to be conducted. (author)

  5. Experimental and numerical investigation of a RC wall loaded by snow-like avalanche pressure signal

    Science.gov (United States)

    Ousset, Isabelle; Bertrand, David; Brun, Michaël; Limam, Ali; Naaïm, Mohamed

    2013-04-01

    Nowadays, civil engineering structures exposed to snow avalanches are mostly designed considering static loadings involving large safety factors. These latters highlight the lack of knowledge about the effects of the loading generated by a snow flow, and generally lead to oversize the civil structure. Indeed, the transient nature of the loading signal and also the composition of the snow flow can generate dynamic phenomena which cannot be taken into account considering only static loadings. The case of the avalanche of the Taconnaz (France), which occurred in 1999 and where important parts of the defense structure were destroyed, showed that static design approaches can lead to underestimate the potential effect of the snow flow. Thus, in order to give some new insights about this issue, the effect of the temporal variations of the snow loading on the mechanical behavior of an idealized defense structure is investigated. Therefore, a reinforced concrete (RC) wall with a L-like shape has been considered which is supposed to represent a part of the defense structure situated in Taconnaz. Static pushover tests, carried out in laboratory conditions on 1/6 scale physical model of the RC structure, allowed obtaining the capacity of the tested structure (Berthet-Rambaud et al. (2007)). Finite Element (FE) models have been developed and calibrated from the previous experimental data. The FE approach allows simulating the dynamic mechanical response of the structure. The effect of the transient nature of the loading of the avalanche has been explored applying out-of-plan dynamic loadings on the RC wall. In order to be as close as possible of a "field" snow avalanche, the imposed time evolution of the loading has been generated from in situ measurements recorded at the French experimental site "le col du Lautaret" (Thibert et al. (2008)). The RC mechanical behaviour has been described by four nonlinear constitutive laws. The four behaviour laws are compared and analyzed for specific loading situations. Next, the influences of typical parameters characterizing the avalanche loading signal are proposed. In particular, a special focused is presented on the effect of the loading rate. Finally, the vulnerability of the RC wall is studied in a reliability framework. Damage index are proposed and the probability of failure of the RC wall is derived. These relations might be useful for risk analysis.

  6. Horonobe Underground Research Laboratory project. Investigation program for the 2008 fiscal year (Translated document)

    International Nuclear Information System (INIS)

    As part of the research and development program on the geological disposal of high-level radioactive waste (HLW), the Horonobe Underground Research Center, a division of the Japan Atomic Energy Agency (JAEA), is implementing the Horonobe Underground Research Laboratory Project (Horonobe URL Project) with the aim at investigating sedimentary rock formations. According to the research plan described in the Midterm Plan of JAEA, geological investigations are to be carried out during the drilling of a shaft down to intermediate depth, while research and development in the areas of engineering technology and safety assessment are to be promoted by collaboration with other research organizations. The results of the R and D activities will be systematized as a 'knowledge base' that supports a wide range of arguments related to the safety of geological disposal. The Horonobe URL Project 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 investigation program for the 2008 fiscal year (2008/2009), the 4th year of the Phase 2 investigations. In the 2008 fiscal year, investigations in 'geoscientific research', including 'development of techniques for investigating the geological environment', 'development of techniques for use in the deep underground environment' and 'studies on the long-term stability of the geological environment', are continuously carried out. Investigations in 'research and development on geological disposal technology', including 'improving the reliability of disposal technologies' and 'enhancement of safety assessment methodologies', are also continuously carried out. Construction of the underground facilities is ongoing at the Ventilation shaft and the East access shaft. Pilot boring close to the Ventilation shaft is also carried out. Regarding the surface facilities, construction of the International Communication House (tentative name) will be started. (author)

  7. Geological investigations for geological model of deep underground geoenvironment at the Mizunami Underground Research Laboratory (MIU)

    International Nuclear Information System (INIS)

    Japan Atomic Energy Agency (JAEA) is performing a geoscientific research project, the Mizunami Underground Research Laboratory (MIU) project, in order to establish scientific and technological basis for geological disposal of high-level radioactive wastes. The MIU is located in crystalline rock environment, in Mizunami City, central Japan. Field investigations include geological mapping, reflection seismic surveys, several borehole investigations and geological investigations in the research galleries to identify the distribution and heterogeneity of fractures and faults that are potential major flowpaths for groundwater. The results of these field investigations are synthesized and compiled for the purpose of geological modeling. The field investigations indicate that the Main Shaft at the MIU intersected low permeability NNW oriented faults. A high permeability fracture zone in the granite, a significant water inflow point, was observed in the Ventilation Shaft. Development of the geological model focusing 3D spatial relationships at different scales and evolution of the geoenvironment are underway. This paper describes geological investigations applied in the MIU project, focusing on the evaluation of their effectiveness to understand for deep underground geoenvironment. (author)

  8. Laboratory Investigation of Contact Freezing and the Aerosol to Ice Crystal Transformation Process

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Raymond A. [Michigan Technological University

    2014-10-28

    This project has been focused on the following objectives: 1. Investigations of the physical processes governing immersion versus contact nucleation, specifically surface-induced crystallization; 2. Development of a quadrupole particle trap with full thermodynamic control over the temperature range 0 to –40 °C and precisely controlled water vapor saturation ratios for continuous, single-particle measurement of the aerosol to ice crystal transformation process for realistic ice nuclei; 3. Understanding the role of ice nucleation in determining the microphysical properties of mixed-phase clouds, within a framework that allows bridging between laboratory and field measurements.

  9. NNWSI [Nevada Nuclear Waste Storage Investigations] waste form testing at Argonne National Laboratory

    International Nuclear Information System (INIS)

    The Chemical Technology Division of Argonne National Laboratory is performing experiments in support of the waste package development of the Yucca Mountain Project (formerly the Nevada Nuclear Waste Storage Investigations Project). Experiments in progress include (1) the development and performance of a durability test in unsaturated conditions, (2) studies of waste form behavior in an irradiated atmosphere, (3) studies of behavior in water vapor, and (4) studies of naturally occurring glasses to be used as analogues for waste glass behavior. This report documents progress made during the period of January--June 1988. 21 refs., 37 figs., 12 tabs

  10. Laboratory animals pulmonary clearance study with chromium 51 labelled polystyrene spherical particles: investigations for clinical application

    International Nuclear Information System (INIS)

    Polystyrene spherical particles labelled with chromium 51, retaining a small amount of chromium acetylacetonate, were administered through different ways to laboratory animals, mice, rats, dogs and monkeys, in order to work out a suitable technique for clinical investigations. The following results were obtained: radioactive labelling may be considered as stable because in vivo chromium elution from the particles does not exceed 0.1% daily. No short-term toxicity has been found for any of the ways of administration due to acetylacetonate or the particles themselves. Long-term pulmonary clearance of inhaled polystyrene particles is close to that of metallic oxides, and no detectable nuisance was observed

  11. Diagnostic value of laboratory and scintigraphic investigations in young infants with cholestatic jaundice

    International Nuclear Information System (INIS)

    The diagnostic value of laboratory and scintigraphic examination techniques in young infants with cholestatic jaundice will be discussed. The correct diagnosis of neonatal hepatitis or extrahepatic biliary atresia cannot be derived from such investigations as determination of bilirubin, enzyme activities, immunologic or serologic parameters or scintigraphy of the liver. Only quantitative changes of serum LP-X before and after administration of cholestyramin and the modified rose-bengal test may help to establish a correct diagnosis in cholestatic jaundice during the first 6 weeks of life. (orig.)

  12. Numerical investigation of chaotic advection past a groyne based on laboratory flow experiment

    Science.gov (United States)

    Zsugyel, Márton; Tél, Tamás; Józsa, János

    2014-09-01

    A laboratory flow past a groyne with complex hydrodynamics was investigated using surface Particle Tracking Velocimetry (PTV) technique for detecting chaotic features in fluvial mixing processes. In the reconstructed velocity field particles were deployed and tracked numerically in a Lagrangian way. Calculating some appropriate parameters (e.g. flushing times, finite-size Lyapunov exponent) originating from chaos theory, we are able to give a more detailed picture on surface mixing driven by aperiodic flows than traditional approaches, including the separation of sub-regions characterized by sharply different mixing efficiency.

  13. Project Management Plan for the Idaho National Engineering Laboratory Waste Isolation Pilot Plant Experimental Test Program

    International Nuclear Information System (INIS)

    EG ampersand G Idaho, Inc. and Argonne National Laboratory-West (ANL-W) are participating in the Idaho National Engineering Laboratory's (INEL's) Waste Isolation Pilot Plant (WIPP) Experimental Test Program (WETP). The purpose of the INEL WET is to provide chemical, physical, and radiochemical data on transuranic (TRU) waste to be stored at WIPP. The waste characterization data collected will be used to support the WIPP Performance Assessment (PA), development of the disposal No-Migration Variance Petition (NMVP), and to support the WIPP disposal decision. The PA is an analysis required by the Code of Federal Regulations (CFR), Title 40, Part 191 (40 CFR 191), which identifies the processes and events that may affect the disposal system (WIPP) and examines the effects of those processes and events on the performance of WIPP. A NMVP is required for the WIPP by 40 CFR 268 in order to dispose of land disposal restriction (LDR) mixed TRU waste in WIPP. It is anticipated that the detailed Resource Conservation and Recovery Act (RCRA) waste characterization data of all INEL retrievably-stored TRU waste to be stored in WIPP will be required for the NMVP. Waste characterization requirements for PA and RCRA may not necessarily be identical. Waste characterization requirements for the PA will be defined by Sandia National Laboratories. The requirements for RCRA are defined in 40 CFR 268, WIPP RCRA Part B Application Waste Analysis Plan (WAP), and WIPP Waste Characterization Program Plan (WWCP). This Project Management Plan (PMP) addresses only the characterization of the contact handled (CH) TRU waste at the INEL. This document will address all work in which EG ampersand G Idaho is responsible concerning the INEL WETP. Even though EG ampersand G Idaho has no responsibility for the work that ANL-W is performing, EG ampersand G Idaho will keep a current status and provide a project coordination effort with ANL-W to ensure that the INEL, as a whole, is effectively and efficiently completing the requirements for WETP

  14. Laboratory Investigation Of Partial Replacement Of Coarse Aggregate By Plastic Chips And Cement By Human Hair

    OpenAIRE

    Balaji, A. S.; Mohan Kumar, D.

    2014-01-01

    The use of plastic is increasing day by day, although steps were taken to reduce its consumption. The suitability of recycled plastics as coarse aggregate in concrete and its advantage are discussed here. Experimental investigation was done using M20 mix and tests were carried out as per recommended procedures by relevant codes. As 100% replacement of natural coarse aggregate (NCA) with plastic coarse aggregate (PCA) is not feasible, partial replacement were examined. And also...

  15. Survey on current status of laboratory test method and experimental consideration for material containing bentonite

    International Nuclear Information System (INIS)

    In the joint study between CRIEPI and JAEA, in order to establish laboratory test method of bentonite, literature survey as well as laboratory tests were conducted to find factors affecting the results of laboratory tests for bentonite and to estimate their degree of influence. Countermeasures against the factors are also investigated in this joint study. This report showed hydraulic conductivity tests and swelling pressure tests those are important in the low-level radioactive waste disposal. 1. Hydraulic conductivity. According to the results of literature survey, it is revealed that constant pressure permeability test and consolidation test are currently used for measuring hydraulic conductivity of bentonite and that (1) hydraulic gradient, (2) local seepage flow between lateral surface of the specimen and lateral wall of the container, (3) water pressure which is applied to the specimen, (4) degree of saturation and (5) size of the specimen possibly affect the results of the constant pressure permeability test, (6) friction between lateral surface of the specimen and lateral wall of the container accompanied by deformation of the specimen, (7) consolidation pressure together with factors (8), (9) affect the results of the consolidation test. As a result of investigation, it is concluded that it is currently desirable to use the constant pressure permeability test for compacted bentonite because there seems no major affecting factor which cannot be removed. 2. Swelng factor which cannot be removed. 2. Swelling pressure. According to the literature survey, confined type testing apparatuses and apparatuses which are similar to the consolidation test apparatuses are used for measuring swelling pressure. Factors affecting results of swelling pressure tests are saturation of the specimen, size of the specimen and difference of apparatus. Saturation of the specimen set in confined type testing apparatus can be raised easily by one-dimensional infiltration of water through the specimen and by applying backpressure. It is revealed that size of the specimen affects the test results if effective clay density is larger than 1.6 Mg/m3. Though swelling pressure measured by the confined type test apparatus is larger than that by apparatuses which are similar to the consolidation test apparatuses, further study is needed to clarify the cause of the difference. (author)

  16. An experimental set up for investigating the reactive transfer of hydrocarbons in soils under unsaturated conditions (air, water, oil)

    International Nuclear Information System (INIS)

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known especially in the unsaturated zone. Investigations of processes in the unsaturated zone are confronted to two major problems (a) sampling under field conditions, (b) obtaining conditions representative of the field in laboratory experiments. We present here an innovative experimental set up to investigate degradation processes under steady state unsaturated conditions in a soil column. We developed a protocol to build a physical column model of contaminated soils. This setup permits fixing partial water and oil saturation at nearly constant values throughout the whole length of the column. This homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, is achieved using ceramic membranes placed at the bottom of the soil column. The partial saturation takes place in two steps, introduction and drainage first of water using a water wettable membrane, followed by introduction and drainage of the oil phase using an oil wettable membrane. Using our experimental set up, many factors can be controlled and modified to investigate their influence on the kinetics of biodegradation. (authors)

  17. Laboratory investigation of constitutive property up-scaling in volcanic tuffs

    International Nuclear Information System (INIS)

    One of the critical issues facing the Yucca Mountain site characterization and performance assessment programs is the manner in which property up-scaling is addressed. Property up-scaling becomes an issue whenever heterogeneous media properties are measured at one scale but applied at another. A research program has been established to challenge current understanding of property up-scaling with the aim of developing and testing improved models that describe up-scaling behavior in a quantitative manner. Up-scaling of constitutive rock properties is investigated through physical experimentation involving the collection of suites of gas-permeability data measured over a range of discrete scales. To date, up-scaling studies have been performed on a series of tuff and sandstone (used as experimental controls) blocks. Samples include a welded, anisotropic tuff (Tiva Canyon Member of the Paintbrush Tuff, upper cliff microstratigraphic unit), and a moderately welded tuff (Tiva Canyon Member of the Paintbrush Tuff, Caprock microstratigraphic unit). A massive fluvial sandstone (Berea Sandstone) was also investigated as a means of evaluating the experimental program and to provide a point of comparison for the tuff data. Because unsaturated flow is of prime interest to the Yucca Mountain Program, scoping studies aimed at investigating the up-scaling of hydraulic properties under various saturated conditions were performed to compliment these studies of intrinsic permeability. These studies focused on matrix sorptivity, a constitutive property quantifying the capillarity of a porous medium. 113 refs

  18. Investigations on the metabolic fate of prochloraz in soil under field and laboratory conditions

    International Nuclear Information System (INIS)

    The degradation of prochloraz in different soils was investigated in field and laboratory experiments. In laboratory degradation experiments in the dark, initial prochloraz concentrations decreased to 30–64% within 56 days, depending on temperature and soil pH. In neutral to basic soils, formation of up to 3.7% of the metabolite prochloraz-urea was observed. The rate of mineralization was strongly pH-dependent, not exceeding 3.2% in the acidic and 18.3% in the neutral to basic soils. Amounts of non-extractable residues ranged from 14 to 31%. Under field conditions, prochloraz disappeared much more rapidly with DT50 values of 11–43 days. The metabolites prochloraz-formylurea and prochloraz-urea were found in significant concentrations. Laboratory experiments with fresh and sterilized soils under UV irradiation confirmed the enhancing effect of light on the formation of the primary metabolite, prochloraz-formylurea. The latter is hydrolysed to prochloraz-urea predominantly by microbial degradation. (author)

  19. Horonobe underground research laboratory project investigation report for the 2005 fiscal year

    International Nuclear Information System (INIS)

    The investigations in 2005 fiscal year (2005/2006) were focused on the Hokushin area, which was selected as the area for laboratory construction. The main investigation region extends over approximately 3 km x 3 km. Geophysical, geological and surface hydrogeological investigations are carried out to acquire the geoscientific data needed to develop techniques for investigating the geological environment. And the borehole investigation at HDB-11 was finished in 2005. About development of techniques for long-term monitoring of the geological environment, long-term monitoring systems were operative in boreholes drilled in a previous investigation, and were also installed in the remaining boreholes (HDB-9, 10; drilled in 2004). A remotely operated monitoring system (ACROSS) was also installed and tested. About study on long-term stability of the geological environment, for tracing tectonic changes at Horonobe, geological survey and ground penetrating radar were carried out. Observations using seismograph, global positioning system (GPS) and electromagnetic exploration system installed until 2006 were continuing. About improving the reliability of disposal technology, laboratory tests of low alkaline concrete, shotcrete test at full-size simulated tunnel were carried out. Applicability confirmation of EBS designing methods was carried out with geological environmental data of Phase 1. About sophistication of safety assessment methodologies, Sorption test using drill core was carried out. Solute transport analysis was also carried out. In parallel with these investigations, Phase 2 investigation program were planned. About surface facility, Research and Administration Facility and Test Facility were constructed and started to use since February 2006. Public information house was begun to construct. About underground facility, temporary surplus soil (muck) yard was constructed. Surplus soil yard and drainage line were designed. These caused by toxic substance founded in borehole investigations. Steel pipe piles were drove as foundation of ventilation shaft's entrance. Then ventilation shaft were excavated at about 5 meter from ground level. Aeration test using underground facility's model aimed for improving the reliability of emergency management were carried out. About environmental survey, environmental monitoring was ongoing around URL area. Collaboration with experts from domestic and overseas research institute (such as H-RISE, Hokkaido Univ., CRIEPI and so on) was continued to form an important part of the program. (author)

  20. Experimental investigations from conventional to high speed milling on a 304-L stainless steel

    OpenAIRE

    Maurel-pantel, Aurelien; Fontaine, Michael; Michel, Ge?rard; Thibaud, Se?bastien; Gelin, Jean-claude

    2013-01-01

    Last years analytical or finite element models of milling become more efficient and focus on more physical aspects, nevertheless the milling process is still experimentally unknown on a wide range of use. This paper propose to analyse with accuracy milling operations by investigating the cutting forces values, shape of cutting forces curves obtained for different cutting speeds, and related phenomena as tool wear or tool run-out. These detailed experimental data in milling constitute a suitab...