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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

1980-07-31

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Experimental results of the investigation of a laboratory cold seal TEC  

Energy Technology Data Exchange (ETDEWEB)

The results of experimental investigation of characteristics of a laboratory Cold Seal Thermionic Energy Converter (CS TEC) with a built-in gas regulated heat pipe are discussed. They were obtained to justify the electric-thermal-physical characteristics of a flame heated CS TEC. The CS TEC design is being developed by a joint Russian-Dutch team of researchers with support of the Netherlands Organization for Scientific Research (NWO). The concept of this flame heated Cold Seal TEC was presented in a previous publication. This paper deals with experimental data on the emission properties of electrodes and the voltage-current characteristics (JVC) of an electrically heated laboratory TEC. They were studied over a wide interval of variation in the electrode temperature and interelectrode distance. The cesium vapour working pressure in the interelectrode space was regulated both by the conventional method (using a cesium reservoir) and by means of a gas regulated cesium heat pipe. This allows one to use a rubber (viton) seal in the non-condensing gas (argon) area. The acquired experimental characteristics will allow one to identify the inner parameters at further stages of their work when testing the full-scale flame heated CS TEC.

Yarygin, V.I.; Mironov, V.S.; Kiryushenko, A.I.; Mikheyev, A.S.; Tulin, S.M.; Meleta, Y.A.; Yarygin, D.V.; Wolff, L.R.

1998-07-01

3

Computational and experimental investigation of scour past laboratory models of stream restoration rock structures  

Science.gov (United States)

Local scour of the streambed around three models of stream restoration rock structures, including a rock vane, a cross vane, and a J-hook vane, is investigated via laboratory experiments and numerical simulations. In the experimental study, a physical model of each rock structure is constructed via an assembly of rocks and installed in a straight mobile sand bed flume. Continuous bed topography measurements provide insight into the time evolution of the scour patterns downstream of the structures and yield comprehensive data sets for validating the numerical simulations in terms of scour patterns, maximum scour depths, and bar migration dynamics. The numerical simulations are carried out using the coupled, hydro-morphodynamic Curvilinear Immersed Boundary (CURVIB) method of Khosronejad et al. (2011) [17]. The mobile channel bed and the individual rocks comprising a stream restoration structure are discretized with an unstructured triangular mesh and treated as sharp-interface immersed boundaries embedded in the background curvilinear mesh used to discretize the flow domain. For each case, simulations are carried out solving both the unsteady Reynolds-averaged Navier-Stokes (URANS) equations closed with the k-? model and filtered Large-Eddy Simulation (LES) equations closed with the dynamic Smagorinski subgrid scale model. Both the URANS and LES models yield flow and scour patterns in reasonable agreement with the measurements with the LES results being consistently in better overall agreement with the measurements. To our knowledge, the present study is the first attempt to simulate local scour patterns around realistic model of stream restoration rock structures by taking into account and directly modeling their arbitrarily complex geometrical features.

Khosronejad, Ali; Hill, Craig; Kang, Seokkoo; Sotiropoulos, Fotis

2013-04-01

4

Experimental investigation on gaseous emissions from the combustion of date palm residues in laboratory scale furnace.  

UK PubMed Central (United Kingdom)

Emissions characteristics from the combustion of five date palm residues, DPR, (Date Palm Leaflets, Date Palm Rachis, Date Palm Trunk, Date Stones and fruitstalk prunings) in a laboratory scale furnace were investigated. Release of gaseous products such as CO2, CO, VOC, NOx and SO2 were measured at 600-800°C. The main goal was to analyze thermal behaviors and gaseous emissions in order to select the most convenient biofuel for an application in domestic boiler installations. Regards to biofuel characteristics, date stone have the highest energy density (11.4GJ/m(3)) and the lowest ash content (close to 1.2%). Combustion tests show that among the tested date palm residues, date stone may be the promising biofuel for the design of combustion processing system. However, a special attention to the design of the secondary air supply should be given to prevent high emissions of CO and volatile matters.

El may Y; Jeguirim M; Dorge S; Trouvé G; Said R

2013-03-01

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Experimental investigation on gaseous emissions from the combustion of date palm residues in laboratory scale furnace.  

Science.gov (United States)

Emissions characteristics from the combustion of five date palm residues, DPR, (Date Palm Leaflets, Date Palm Rachis, Date Palm Trunk, Date Stones and fruitstalk prunings) in a laboratory scale furnace were investigated. Release of gaseous products such as CO2, CO, VOC, NOx and SO2 were measured at 600-800°C. The main goal was to analyze thermal behaviors and gaseous emissions in order to select the most convenient biofuel for an application in domestic boiler installations. Regards to biofuel characteristics, date stone have the highest energy density (11.4GJ/m(3)) and the lowest ash content (close to 1.2%). Combustion tests show that among the tested date palm residues, date stone may be the promising biofuel for the design of combustion processing system. However, a special attention to the design of the secondary air supply should be given to prevent high emissions of CO and volatile matters. PMID:23347919

El may, Yassine; Jeguirim, Mejdi; Dorge, Sophie; Trouvé, Gwenaelle; Said, Rachid

2012-12-26

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Laboratory Experimentation in Economics  

Directory of Open Access Journals (Sweden)

Full Text Available 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 experiments. Experiments may be conducted in the field or in laboratory settings, whether of individual or group behavior. Variants of the subject outside such formal confines include natural and quasi-natural experiments.

Dimitrios Koumparoulis

2013-01-01

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USE OF SIMULATORS FOR LABORATORY EQUIPMENT IN ACTIVITY OF INVESTIGATIVE PLAYFUL EXPERIMENTATION IN SECONDARY SCHOOLS  

Directory of Open Access Journals (Sweden)

Full Text Available This article relates the construction and the use of simulators of laboratory materials in activities of simpleexperimentation, using material and alternative reagent. Apart from not residually interfering with theenvironment, the manipulation of the aforementioned materials does not expose students to any risk. Thereby,such activities can be developed especially in those schools in which a laboratory is not available. Thesimulators perfectly responded to the expected purposes of the activities, demonstrating the possibility ofbecoming an excellent didactic resource. The 50 minutes period was enough to develop each individual activity;furthermore, the classroom was the physical space used for the execution of such activities. At the beginning, astudy case was presented and students were encouraged to formulate and discuss their hypothesis. In thecourse of the activities, it was possible to bring students to deconstruct concepts of common sense related tothe themes discussed – acid, base, separation of mixtures, amongst others – reconstructing them from thescientific sense. This reconstruction took place in a relaxed atmosphere in which mistakes were correctedwithout resulting in embarrassments. Meanings were not imposed; instead, they were built by all. Somestudents reconsidered their initial concepts – incorrect knowledge they had about a specific phenomenon –welcoming the ideas from other students who were better able to explain such phenomenon.

OLIVEIRA, N.; BENEDETI, F. E.; FIORUCCI, A. R.; BENEDETTI, L. P. dos S.; BELOTO, M. R. M. de O.

2011-01-01

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

CERN Multimedia

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

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

2004-01-01

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

Science.gov (United States)

The large-scale effects of anthropogenic CO2 rise and global ocean acidification on calcifying and photosynthetic organisms are not well understood. This ongoing uncertainty fundamentally limits our ability to fully understand global carbon cycling. Field-based studies are limited to the current environmental chemistries observed throughout the world's oceans - a prohibitively resource-intensive platform for manipulative experimentation. Moreover, complex carbonate system equilibria decoupled from the atmosphere are difficult to poise and maintain in laboratory seawater-based experiments lasting longer than a few hours or days. This severely limits the scope of biogeochemical experimentation for simulating past or future ocean chemistries. To address these experimental shortcomings we developed a novel system for the stringent control of pCO2 in culture aeration and seawater. A custom CO2 scrubbing system was designed which removes > 99.8% of atmospheric CO2 at 3-4 L min-1 aeration rate. High precision mass flow controllers integrated with a modular programmable process controller precisely mix high-purity (99.95%) compressed CO2 with the preconditioned CO2-free air stream for aeration into the culture system. Long-term maintenance of experimental CO2 is within ± 2 ?atm when operating between 150- 2000 ?atm pCO2. The system, in its current configuration, has the ability to simultaneously manipulate and maintain 3 separate carbonate chemistries using aeration pCO2 and seawater alkalinity in independent 400-L seawater reservoirs. Future system expansion can easily maintain 5 or more separate chemistries. The goal of this research is to develop stringent control of seawater carbonate system chemistries for the deep- sea benthic foraminifera cultures housed at the University of South Carolina Arnold School of Public Health. Current experiments are investigating trace metal foraminiferal paleoproxy signatures that appear correlated with [CO32-] very near calcite saturation. Our system's control of equilibrium pCO2 allows precise maintenance of the culture's carbonate system chemistry very near, above and below calcite saturation, while maintaining realistic values for alkalinity and dissolved inorganic carbon. This research was funded by the University of South Carolina Arnold School of Public Health and the National Science Foundation - OCE 0647891.

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

2007-12-01

10

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

2008-01-01

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Experimental Investigations of the Existence of a Local-Time Effect on the Laboratory Scale and the Heterogeneity of Space-Time  

Directory of Open Access Journals (Sweden)

Full Text Available The main subject of this work is an experimental investigation of the existence of a local-time effect on the laboratory scale, i.e. longitudinal distances between locations of measurements from one metre to tens of metres. A short review of our investigations of the existence of a local-time effect for longitudinal distances from 500 m to 15 km is also presented. Besides investigations of the minimal spatial scale for a local-time effect, the paper presents investigations of the effect in the time domain. In this relation the structure of intervals distribution in the neighbourhood of local-time peaks was studied and splitting of the peaks was revealed. Further investigations revealed second order splitting of local-time peaks. From this result it is concluded that space-time heterogeneity, which follows from the local-time effect, probably has fractal character. The results lead to the conclusion of sharp anisotropy of space-time.

Panchelyuga V.A.; Kolombet V.A.; Panchelyuga M.S.; Shnoll S.E.

2007-01-01

12

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

International Nuclear Information System (INIS)

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

1982-01-01

13

Experimental investigation of cavity flows  

Energy Technology Data Exchange (ETDEWEB)

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

Loeland, Tore

1998-12-31

14

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)

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

Zhang Xiaojing

1997-05-01

15

Experimental Laboratory Tooling for Deep Drawing Process  

Science.gov (United States)

New trends in the deep drawing of tailored blanks demands for the analysis of process parameters and their setup to obtain the drawn parts with required shape precision, strength and stiffness. One option is to perform the experiments, measurements and optimization of that process on an experimental laboratory device and to compare the results to those from simulations. This contribution deals with the redesign of a device that is used at the Institute of technologies and materials with regard to replacement of strain gauge force measuring system by piezoelectric force measuring system. The new design is also focused on a new way of setting the blankholder pressure applied on the tailored blank.

Schrek, Alexander; ?inák, Michal; Žit?anský, Peter

2011-12-01

16

Experimental and Theoretical Investigations on Laboratory Models of Phased Array Antennas Experimentelle und Theoretische Untersuchungen an Labormodellen von Phased Array Antennen.  

Science.gov (United States)

Investigations on planar arrays of waveguide-fed aperture antennas scanned in the X-band are reported. A complete planar array of 18x18 antennas was constructed, of which 8x8 elements in the middle were fed and phased-controlled. Its scanning ability was ...

H. Lueg

1977-01-01

17

Experimental investigations of ICRF effects  

International Nuclear Information System (INIS)

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

1991-01-01

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Alfred Binet and experimental psychology at the Sorbonne laboratory.  

UK PubMed Central (United Kingdom)

Between 1892 and 1904, Alfred Binet (1857-1911) produced, in the psychology laboratory of the Sorbonne, a whole set of original works that still remains little known today. He integrated the laboratory, directed by the psychophysiologist Henry Beaunis (1830-1921), in 1891. We describe the circumstances that led Binet to take the direction of this laboratory in 1895 and present scientific investigations that were conducted there by Binet and his collaborators. For Binet, the laboratory was not narrowly limited to a set of rooms where experiments were conducted by means of sophisticated devices (experimental psychology), it was also a working area, regularly organized, where all the psychological documents were classified, whatever their origin (descriptive psychology). We show that Binet was a pioneer who is still little recognized in various areas of experimental psychology. Binet suffered, at the time, from the indifference of his contemporaries, but he especially regretted not being able to attract students to his laboratory due to the absence of diploma-offering programs. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

Nicolas S; Sanitioso RB

2012-11-01

19

Alfred Binet and experimental psychology at the Sorbonne laboratory.  

Science.gov (United States)

Between 1892 and 1904, Alfred Binet (1857-1911) produced, in the psychology laboratory of the Sorbonne, a whole set of original works that still remains little known today. He integrated the laboratory, directed by the psychophysiologist Henry Beaunis (1830-1921), in 1891. We describe the circumstances that led Binet to take the direction of this laboratory in 1895 and present scientific investigations that were conducted there by Binet and his collaborators. For Binet, the laboratory was not narrowly limited to a set of rooms where experiments were conducted by means of sophisticated devices (experimental psychology), it was also a working area, regularly organized, where all the psychological documents were classified, whatever their origin (descriptive psychology). We show that Binet was a pioneer who is still little recognized in various areas of experimental psychology. Binet suffered, at the time, from the indifference of his contemporaries, but he especially regretted not being able to attract students to his laboratory due to the absence of diploma-offering programs. (PsycINFO Database Record (c) 2012 APA, all rights reserved). PMID:23397922

Nicolas, Serge; Sanitioso, Rasyid Bo

2012-11-01

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

1994-01-01

 
 
 
 
21

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.

2012-11-26

22

Experimental Investigation of Microstructured Evaporators  

Science.gov (United States)

Microfluidic devices have become more and more popular over the last decades [1]. 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 [2]. 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 [2] for the evaporation of R134a in straight microchannels.

Wibel, W.; Westermann, S.; Maikowske, S.; Brandner, J. J.

2012-11-01

23

Numerical and Laboratory Investigations of Regolith Dynamics  

Science.gov (United States)

Surfaces of planets and small bodies in our Solar System are often covered by a layer of granular material that can range from a fine regolith to a gravel-like structure of varying depths. Therefore, the dynamics of granular materials is involved in many events occurring during planetary and small-body evolution and contributes to their geological properties. However from planets to asteroids, surface gravities vary by many orders of magnitude. Bodies with low surface gravity can be sensitive to processes that appear irrelevant in the case of larger planetary bodies. For instance, seismic vibration induced by small impacts has been proposed to explain the lack of very small craters on Eros and Itokawa. To increase our understanding of regolith behaviour we have performed a series of numerical simulations and microgravity experiments. The numerical code is a modified version of the N-body code pkdgrav that has been adapted to handle hard-body collisions. The granular dynamics modifications consist primarily of providing wall "primitives” to simulate the boundaries of the experimental apparatus [1]. Our simulations currently focus on experiments for which we have experimental data. This allows direct comparisons to be made with laboratory experiments. Some specific examples which will be presented are the collective motion of granular materials in a dense regime as a result of shaking, avalanching behaviour and granular flows with a tumbler. The microgravity experiment, AstEx that flew in November 2009 as part of ESA's `Fly your Thesis’ programme will also be presented. The experimental aim was to characterise the response of granular material to rotational shear forces in a microgravity environment. This work benefits from financial support from TAS, the OU, the French Programme National de Planétologie, ESA and the RAS. DCR acknowledges support from NASA (Grant No. NNX08AM39G). Reference: [1] Richardson, D.C. et al., Icarus (2010), submitted.

Murdoch, Naomi; Michel, P.; Berardi, C.; Losert, W.; Richardson, D. C.; Rozitis, B.; Walsh, K. J.; Green, S. F.; de Lophem, T.

2010-10-01

24

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

1987-01-01

25

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.

1989-06-03

26

Experimental investigation of smouldering in biomass  

Energy Technology Data Exchange (ETDEWEB)

The smouldering process of wood logs was studied experimentally in a laboratory facility and in prescribed forest burns. The main goal was to check the parameters that initiate and control the stability of the smouldering process. To do so, sample temperatures at five different locations and concentrations of CO, CO{sub 2} and O{sub 2} were measured and discussed. By varying the temperature and air supply of the flow tunnel apparatus, different rates of smoulder propagation were identified. In prescribed burns, the main characteristics of the self-sustained smouldering combustion front in logs of different sizes and species are reported. The average smouldering speed in the field is about one order of magnitude lower than that reported for different materials in laboratory experiments. (author)

Carvalho, E.R. [Universidade Estadual Paulista (Brazil). Dpto. de Energia; Gurgel Veras, C.A. [Universidade de Brasilia (Brazil); Carvalho, J.A. Jnr. [Universidade Estadual Paulista (Brazil). Dpto. de Energia; Instituto Nacional de Pesquisas (Brazil)

2002-04-01

27

Fusion of Laboratory and Textual Data for Investigative Bioforensics  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-03-10

28

Fusion of laboratory and textual data for investigative bioforensics.  

UK PubMed Central (United Kingdom)

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.

Webb-Robertson BJ; Corley C; McCue LA; Wahl K; Kreuzer H

2013-03-01

29

A Meaningful Experience in Laboratory Investigation  

Science.gov (United States)

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

Szinai, S. S.; Szinai, N.

1976-01-01

30

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).

1986-01-01

31

(Hyperfine experimental investigation of zirconia ceramics)  

Energy Technology Data Exchange (ETDEWEB)

This research program has encompassed a broad investigation of microscopic structure and point defect properties in insulating materials and some recent exploratory work on semiconductors. The major experimental technique is perturbed angular correlation (PAC) spectroscopy. Our research provides information about the microscopic structure, nucleation, and equilibrium of structural phases in materials under investigation. We have studied phase equilibria in monoclinic, tetragonal, and cubic zirconia in the past and have recently begun more detailed investigation of high-temperature anomalies in monoclinic zirconia and tetragonal stabilized zirconia. We also have found a number of instances where the indium PAC probe has detected subtle phase changes, small precipitate formation, and other phase behavior that are difficult to detect by conventional diffraction methods. The PAC experimental technique is described briefly in section 2, and recent research is reviewed in section 3.

1992-01-01

32

Interim analyses of data as they accumulate in laboratory experimentation  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Techniques for interim analysis, the statistical analysis of results while they are still accumulating, are highly-developed in the setting of clinical trials. But in the setting of laboratory experiments such analyses are usually conducted secretly and with no provisions for the necessary adjustments of the Type I error-rate. Discussion Laboratory researchers, from ignorance or by design, often analyse their results before the final number of experimental units (humans, animals, tissues or cells) has been reached. If this is done in an uncontrolled fashion, the pejorative term 'peeking' has been applied. A statistical penalty must be exacted. This is because if enough interim analyses are conducted, and if the outcome of the trial is on the borderline between 'significant' and 'not significant', ultimately one of the analyses will result in the magical P = 0.05. I suggest that Armitage's technique of matched-pairs sequential analysis should be considered. The conditions for using this technique are ideal: almost unlimited opportunity for matched pairing, and a short time between commencement of a study and its completion. Both the Type I and Type II error-rates are controlled. And the maximum number of pairs necessary to achieve an outcome, whether P = 0.05 or P > 0.05, can be estimated in advance. Summary Laboratory investigators, if they are to be honest, must adjust the critical value of P if they analyse their data repeatedly. I suggest they should consider employing matched-pairs sequential analysis in designing their experiments.

Ludbrook John

2003-01-01

33

Angiostrongyliasis in Thailand: epidemiology and laboratory investigations.  

Science.gov (United States)

Cerebral angiostrongyliasis due to Angiostrongylus cantonensis continues to affect human health and productivity in Thailand. The dietary habits of the populace have been an important contributing factor, particularly in the northeast of the country where the disease is endemic and the indigenous people enjoy a local undercooked snail dish called "koi-hoi". Hundreds of cases of disease continue to be reported annually. Because of the difficulty in obtaining a definitive diagnosis, immunological methods have played an important role in the confirmation of A. cantonensis infection. Although enzyme-linked immunosorbent assay (ELISA) and immunoblot are test formats that have been used over the past decade, modern molecular approaches, such as PCR-based diagnostic techniques, are being developed and assessed as additional tests for the diagnosis of cerebral angiostrongyliasis. This short review focuses on the history, incidence, and laboratory diagnosis of angiostrongyliasis in Thailand. PMID:23901379

Eamsobhana, Praphathip

2013-06-01

34

Angiostrongyliasis in Thailand: epidemiology and laboratory investigations.  

UK PubMed Central (United Kingdom)

Cerebral angiostrongyliasis due to Angiostrongylus cantonensis continues to affect human health and productivity in Thailand. The dietary habits of the populace have been an important contributing factor, particularly in the northeast of the country where the disease is endemic and the indigenous people enjoy a local undercooked snail dish called "koi-hoi". Hundreds of cases of disease continue to be reported annually. Because of the difficulty in obtaining a definitive diagnosis, immunological methods have played an important role in the confirmation of A. cantonensis infection. Although enzyme-linked immunosorbent assay (ELISA) and immunoblot are test formats that have been used over the past decade, modern molecular approaches, such as PCR-based diagnostic techniques, are being developed and assessed as additional tests for the diagnosis of cerebral angiostrongyliasis. This short review focuses on the history, incidence, and laboratory diagnosis of angiostrongyliasis in Thailand.

Eamsobhana P

2013-06-01

35

Angiostrongyliasis in Thailand: Epidemiology and Laboratory Investigations  

Science.gov (United States)

Cerebral angiostrongyliasis due to Angiostrongylus cantonensis continues to affect human health and productivity in Thailand. The dietary habits of the populace have been an important contributing factor, particularly in the northeast of the country where the disease is endemic and the indigenous people enjoy a local undercooked snail dish called “koi-hoi”. Hundreds of cases of disease continue to be reported annually. Because of the difficulty in obtaining a definitive diagnosis, immunological methods have played an important role in the confirmation of A. cantonensis infection. Although enzyme-linked immunosorbent assay (ELISA) and immunoblot are test formats that have been used over the past decade, modern molecular approaches, such as PCR-based diagnostic techniques, are being developed and assessed as additional tests for the diagnosis of cerebral angiostrongyliasis. This short review focuses on the history, incidence, and laboratory diagnosis of angiostrongyliasis in Thailand.

2013-01-01

36

Experimental investigation on lithium hydride hydrolysis  

International Nuclear Information System (INIS)

In order to have a better understanding of LiH reaction with water, several experimental techniques were investigated and tested to determine whether they were suitable or not in a kinetic purpose. Among them, Raman spectroscopy and X-Ray photoelectrons spectroscopy (XPS) gave particularly interesting results and are extensively used in the field of our kinetic and phenomenological study of H2 production by LiH hydrolysis. (authors)

2006-01-01

37

Experimental investigation on lithium hydride hydrolysis  

Energy Technology Data Exchange (ETDEWEB)

In order to have a better understanding of LiH reaction with water, several experimental techniques were investigated and tested to determine whether they were suitable or not in a kinetic purpose. Among them, Raman spectroscopy and X-Ray photoelectrons spectroscopy (XPS) gave particularly interesting results and are extensively used in the field of our kinetic and phenomenological study of H{sub 2} production by LiH hydrolysis. (authors)

S Charton; F Delaunay [CEA Valduc, 21120 Is-sur-Tille (France); L Saviot; F Bernard [LRRS-MANAPI, Universite de Bourgogne, BP 47870, 21078 Dijon (France); C Maupoix [CEA Valduc, 21120 Is-sur-Tille (France)]|[LRRS-MANAPI, Universite de Bourgogne, BP 47870, 21078 Dijon, (France)

2006-07-01

38

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)

1993-01-01

39

The European Network of Analytical and Experimental Laboratories for Geosciences  

Science.gov (United States)

Integrating Earth Sciences infrastructures in Europe is the mission of the European Plate Observing System (EPOS).The integration of European analytical, experimental, and analogue laboratories plays a key role in this context and is the task of the EPOS Working Group 6 (WG6). Despite the presence in Europe of high performance infrastructures dedicated to geosciences, there is still limited collaboration in sharing facilities and best practices. The EPOS WG6 aims to overcome this limitation by pushing towards national and trans-national coordination, efficient use of current laboratory infrastructures, and future aggregation of facilities not yet included. This will be attained through the creation of common access and interoperability policies to foster and simplify personnel mobility. The EPOS ambition is to orchestrate European laboratory infrastructures with diverse, complementary tasks and competences into a single, but geographically distributed, infrastructure for rock physics, palaeomagnetism, analytical and experimental petrology and volcanology, and tectonic modeling. The WG6 is presently organizing its thematic core services within the EPOS distributed research infrastructure with the goal of joining the other EPOS communities (geologists, seismologists, volcanologists, etc...) and stakeholders (engineers, risk managers and other geosciences investigators) to: 1) develop tools and services to enhance visitor programs that will mutually benefit visitors and hosts (transnational access); 2) improve support and training activities to make facilities equally accessible to students, young researchers, and experienced users (training and dissemination); 3) collaborate in sharing technological and scientific know-how (transfer of knowledge); 4) optimize interoperability of distributed instrumentation by standardizing data collection, archive, and quality control standards (data preservation and interoperability); 5) implement a unified e-Infrastructure for data analysis, numerical modelling, and joint development and standardization of numerical tools (e-science implementation); 6) collect and store data in a flexible inventory database accessible within and beyond the Earth Sciences community(open access and outreach); 7) connect to environmental and hazard protection agencies, stakeholders, and public to raise consciousness of geo-hazards and geo-resources (innovation for society). We will inform scientists and industrial stakeholders on the most recent WG6 achievements in EPOS and we will show how our community is proceeding to design the thematic core services.

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

2013-04-01

40

Laboratory investigations in cell biology. Second edition  

Energy Technology Data Exchange (ETDEWEB)

This text contains 18 lab projects that explore the structural, biochemical, and physiological nature of eukaryotic cells. Topics are largely traditional, however, several investigations employ new methodologies. Offers extended coverage of biochemistry. Materials have been selected for availability and ease of handling: e.g. Project 4 - extraction of DNA and RNA done with calf liver, Project 9 - succinate dehydrogenase activity studied in mitochondria isolated from cauliflower. There is more procedural detail than found in most lab manuals, negating the need for constant instructional details. And a variety of methodologies is introduced, such as Cytochemistry, Spectrophotometry, Electrophoresis, Cell Fractionation, silver staining of active sites of RNA transcription, and many more. Pages are perforated for collecting and grading.

Bregman, A.A.

1987-01-01

 
 
 
 
41

Experimental investigation of a solar bamboo dryer  

Energy Technology Data Exchange (ETDEWEB)

An experimental investigation was conducted on the performance of a solar box dryer for drying bamboo operating under tropical weather conditions. The dryer is a greenhouse-type designed for multi-crop solar drying. Air circulation was by electrically-operated fan. The results showed that the moisture content of the bamboo could be brought down to about 19% from an initial value of nearly 90% in 17 days by operating the dryer over 8 hours each day. Under natural drying conditions, the final moisture content reached was only 22%. Although solar drying of bamboo was only marginally faster than natural drying, nonetheless, final moisture content was lower.

Ong, K.S. [Univ. Malaya, Kuala Lumpur (Malaysia). Engineering Faculty

1996-05-01

42

Experimental Investigation of Shock Wave Surfing  

CERN Multimedia

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.

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

2010-01-01

43

Experimental investigation of Reykjavik city footbridge  

DEFF Research Database (Denmark)

This study describes experimental investigation of a 160 m long footbridge in Reykjavik. The bridge is a continuous post tensioned concrete beam spanning eight spans, the longest being 27.1 m. In plan, the structure has eye-catching spiral shape. Modal testing of the structure was conducted to identify its dynamic properties. As many as seven modes of vibration were identified in the low-frequency region up to 5 Hz. After this a series of controlled tests involving up to 38 test subjects were performed. These were designed to test vibration performance of the footbridge under various loading scenarios such as: single person either walking or jumping, group of people walking, jogging or jumping and stream of pedestrians. The severity of vibration responses of the bridge for different scenarios was then evaluated against vibration serviceability criteria defined in a guideline. It was found that the vibration performance of the bridge is quite satisfactory for wide range of loading conditions. ©2010 Society forExperimental Mechanics Inc.

Zivanovic, Stana; Ingólfsson, Einar Thór

2011-01-01

44

Experimental investigation of volume Li- production  

International Nuclear Information System (INIS)

[en] An experimental investigation of dissociative attachment in lithium is described. Using laser excitation of a supersonic lithium beam a population of metastable vibrationally-excited lithium molecules has been created in collision-free conditions. Electron-ion pairs have been created by three-step photoionization of lithium atoms in the beam, and the ion signal monitored by pulsed extraction of the Li+ ions. By reversal of the extraction pulse lithium negative ions have been sought at the level of 1 in 2 x 104 electrons attaching to the vibrationally-pumped lithium molecules. The interaction time for attachment is limited by free plasma expansion at the ion acoustic velocity. We have set an upper bound on the attachment rate constant to lithium molecules inu* = 11 andu* = 13 states of k -8 cm3 sec-1, corresponding to an attachment cross section sigma-16 cm2

1984-03-01

45

Experimental investigation of spiral seam induction bends  

Energy Technology Data Exchange (ETDEWEB)

The induction bend is a connecting piece widely used in the pipeline industry. The stress produced by the welding process is significant. This paper reports the experimental investigation of spiral seam induction bends. Three dimension X52 SSAW pipes were used as mother pipes to manufacture the bends through the induction bending process. The study of the spiral seam induction bend used a destructive test sampling plan, which embraces the typical zones of spiral seam induction bend. The study of the mechanical properties and structure of the spiral seam induction bends was performed using Charpy impact test, tensile tests and design proof test. The results showed that the strength-toughness of a spiral seam induction bend approaches the property of mother pipe when the appropriate process is adopted. The guided weld bend tests results also showed that it is difficult to make induction bends with small diameter SSAW pipes.

Chi, Qiang; Wang, Peng; Liu, Yinglai; Ji, Lingkang; Gong, Shaotao [Tubular Goods Research Center, CNPC, Xi' an, (China)

2010-07-01

46

Propane hydrate nucleation: Experimental investigation and correlation  

DEFF Research Database (Denmark)

In this work the nucleation kinetics of propane gas hydrate has been investigated experimentally using a stirred batch reactor. The experiments have been performed isothermally recording the pressure as a function of time. Experiments were conducted at different stirring rates, but in the same supersaturation region. The experiments showed that the gas dissolution rate rather than the induction time of propane hydrate is influenced by a change in agitation. This was especially valid at high stirring rates when the water surface was severely disturbed.Addition of polyvinylpyrrolidone (PVP) to the aqueous phase was found to reduce the gas dissolution rate slightly. However the induction times were prolonged quite substantially upon addition of PVP.The induction time data were correlated using a newly developed induction time model based on crystallization theory also capable of taking into account the presence of additives. In most cases reasonable agreement between the data and the model could be obtained. Theresults revealed that especially the effective surface energy between propane hydrate and water is likely to change when the stirring rate varies from very high to low. The prolongation of induction times according to the model is likely to be due to a change in the nuclei-substrate contact angle.

Jensen, Lars; Thomsen, Kaj

2008-01-01

47

An Investigative, Cooperative Learning Approach to the General Microbiology Laboratory  

Science.gov (United States)

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…

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

2009-01-01

48

Numerical and experimental investigation of downdraft gasification of wood chips  

International Nuclear Information System (INIS)

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

2013-01-01

49

[Laboratory investigation of endocrine function - interpretation of results and pitfalls].  

UK PubMed Central (United Kingdom)

Endocrine disorders are common in internal medicine. Diagnosis of endocrine diseases are usually based on patient history, clinical assessment and laboratory investigations. Thereby, biochemical analyses are used to confirm clinical diagnosis, to assess the need for treatment and to monitor disease progression, in particular to ascertain treatment efficacy. This article will focus on frequently used laboratory investigations for endocrine diseases such as diabetes, thyroid dysfunction, male hypogonadism and adrenal insufficiency. In particular, pre-analytical and analytical variability of biochemical measures as well as its significance in clinical practice will be discussed.

Henzen C; Kraenzlin M; Meier C

2013-08-01

50

Experimental investigations of image quality in xeroradiotomography  

International Nuclear Information System (INIS)

[en] The xeroradiographic image quality of tomograms of structures within and outside the image plane is experimentally investigated using pictures of lead line screens and a dead skull. The lead line screens were inclined with respect to the image plane, so that the imaging quality of details of the image plane and blurring shadows could be quantitatively determined on the basis of the modulation transfer function. The xerotomogram was found to be richer in contrast, sharper, and easier to interpret than conventional screen tomograms. The contrast behaviour in xerotomograms is strongly dependent on the exposure. In a tomogram with optimum exposure, there should be maximum contrast between the structures within the image plane and minimum contrast between structures in the blurred area. The author has found that a compromise must be made between these two demands. For maximum difference between the two types of contrast in xeroradiotomography, images must be slightly underexposed. The blurring effect in xerotomograms is best demonstrated on isolated blurred pictures of slices of the skull phantom. A comparison with screen tomograms shows that the edge enhancement effect, which is a typical characteristic of xeroradiography, is also seen in the blurring shadows so that these get sharper and are less well distinguished from the structures within the image plane. (orig./MG)[de] Das xeroradiographische Abbildungsverhalten der Tomographie von Strukturen innerhalb und ausserhalb der Schichtebene wird an Aufnahmen von Bleistrichrastern und einem Leichenschaedel experimentell untersucht und der herkoemmlichen Technik mit Film-Folien-Kombination gegenuebergestellt. Die Bleistrichraster wurden gegen die Schichtebene schraeggestellt, so dass die Abbildungsqualitaet der Details der Schichtebene und der Verwischungsschatten quantitativ mittels der Modulationsuebertragungsfunktion ermittelt werden konnten. Das Xerotomogramm erscheint kontrastreicher, schaerfer und leichter lesbar als ein vergleichbares Filmtomogramm. Das Kontrastverhalten im Xerotomogramm ist stark von der Belichtung abhaengig. In einem optimal belichteten Tomogramm sollen die Kontraste der abgebildeten Strukturen in der Schichtebene moeglichst gross und die Kontraste der Strukturen, die im Verwischungsbild liegen, moeglichst klein sein. Die eigenen Untersuchungen zeigen, dass zwischen beiden Forderungen ein Kompromiss gefunden werden muss. Wenn die Differenz zwischen beiden Kontrasten bei der Xeroradiotomographie moeglichst gross sein soll, muessen die Aufnahmen etwas unterexponiert werden. Der Verwischungseffekt im Xerotomogramm laesst sich besonders auf isolierten Verwischungsbildern des in Scheiben geschnittenen Schaedelphantoms demonstrieren. Im Vergleich zum Filmtomogramm wird deutlich, dass der dem xeroradiographischen Verfahren eigene Kantenverstaerkungseffekt sich auch an den Verwischungsschatten bemerkbar macht, so dass diese schaerfer dargestellt werden und sich somit schlechter von den abgebildeten Strukturen in der Schichtebene unterscheiden lassen. (orig./MG)

1980-01-01

51

Experimental investigation of the plasma focus discharge  

International Nuclear Information System (INIS)

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

1978-01-01

52

Experimental investigation of smoothing by spectral dispersion  

International Nuclear Information System (INIS)

[en] Measurements of smoothing rates for smoothing by spectral dispersion (SSD) of high-power, solid-state laser beams used for inertial confinement fusion (ICF) research are reported. Smoothing rates were obtained from the intensity distributions of equivalent target plane images for laser pulses of varying duration. Simulations of the experimental data with the known properties of the phase plates and the frequency modulators are in good agreement with the experimental data. These results inspire confidence in extrapolating to higher bandwidths and other SSD configurations that may be suitable for ICF experiments and ultimately for direct-drive laser-fusion ignition. (c) 2000 Optical Society of America

1462-01-00

53

Experimental investigation of aeronautical jet-pump  

Energy Technology Data Exchange (ETDEWEB)

The report describes an experimental plant for the performance analysis of a jet pump used in the aeronautical field. Results of experiments made on a jet pump with JP4 fuel are also presented. The area where cavitation is taking place is given particular attention. Comparisons are made with similar, already published cases.

Massardo, A.; Satta, A.

1988-09-01

54

Experimental investigation of 4-dimensional superspace crystals  

Energy Technology Data Exchange (ETDEWEB)

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.

Rasing, T.; Janner, A.

1983-09-01

55

Experimental investigation of the CO{sub 2} refrigeration cycle  

Energy Technology Data Exchange (ETDEWEB)

Worldwide efforts to reduce the environmentally harmful effects of chlorofluorocarbons revived the study of the CO{sub 2} refrigeration cycle. A laboratory prototype of the CO{sub 2} refrigeration cycle was built to experimentally investigate the cycle's performance potential. The performance of CO{sub 2} was compared with that of R-22 for water-chilling applications. Though the ideal cycle coefficient of performance (COP) of CO{sub 2} is only 50% to 60% that of R-22, the actual CO{sub 2} cycle performs similarly to the R-22 cycle. This large deviation between the ideal cycle and the actual cycle is due to the beneficial thermophysical properties of CO{sub 2}.

Hwang, Y.; Radermacher, R.

1999-07-01

56

Experimental Explosive Characterization for Counterterrorist Investigation  

Science.gov (United States)

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

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

2013-08-01

57

Numerical and experimental investigations on cavitation erosion  

Science.gov (United States)

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.

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

2012-11-01

58

Numerical and experimental investigations on cavitation erosion  

International Nuclear Information System (INIS)

[en] 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.

2012-11-26

59

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

2001-01-01

60

Experimental investigation of cryogenic oscillating heat pipes.  

UK PubMed Central (United Kingdom)

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.

Jiao AJ; Ma HB; Critser JK

2009-07-01

 
 
 
 
61

Experimental investigation of cryogenic oscillating heat pipes.  

Science.gov (United States)

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

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

2009-07-01

62

High range electromagnetic fields. Experimental investigations  

International Nuclear Information System (INIS)

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

2001-01-01

63

Investigation of Appropriate Refractory Material for Laboratory Electritic Resistrance Furnance  

Directory of Open Access Journals (Sweden)

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.

J.B Agboola; O.K Abubakre

2009-01-01

64

An Experimental Investigation of XML Compression Tools  

CERN Multimedia

This paper presents an extensive experimental study of the state-of-the-art of XML compression tools. The study reports the behavior of nine XML compressors using a large corpus of XML documents which covers the different natures and scales of XML documents. In addition to assessing and comparing the performance characteristics of the evaluated XML compression tools, the study tries to assess the effectiveness and practicality of using these tools in the real world. Finally, we provide some guidelines and recommen- dations which are useful for helping developers and users for making an effective decision for selecting the most suitable XML compression tool for their needs.

Sakr, Sherif

2008-01-01

65

Geoengineering characterization of welded tuffs from laboratory and field investigations  

International Nuclear Information System (INIS)

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

1984-01-01

66

Geoengineering characterization of welded tuffs from laboratory and field investigations  

Energy Technology Data Exchange (ETDEWEB)

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

Zimmerman, R.M.; Nimick, F.B.; Board, M.P.

1984-12-31

67

Geoengineering characterization of welded tuffs from laboratory and field investigations  

Energy Technology Data Exchange (ETDEWEB)

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

Zimmerman, R.M.; Nimick, F.B.; Board, M.P.

1984-12-31

68

Experimental investigation of orbitally shaken bioreactor hydrodynamics  

Science.gov (United States)

The growing interest in the use of orbitally shaken bioreactors for mammalian cells cultivation raises challenging hydrodynamic issues. Optimizations of mixing and oxygenation, as well as similarity relations between different culture scales are still lacking. In the present study, we investigated the relation between the shape of the free surface, the mixing process and the velocity fields, using specific image processing of high speed visualization and Laser Doppler velocimetry. Moreover, similarity parameters were identified for scale-up purposes.

Reclari, Martino; Dreyer, Matthieu; Farhat, Mohamed

2010-11-01

69

An experimental investigation on THF hydrate rystallization  

Energy Technology Data Exchange (ETDEWEB)

The metastable zone of THF hydrate crystallization was investigated. It was found that formation of THF hydrate was possible in between solution concentrations of 9 and 46 percent by weight. Induction time for nucleation was also determined. The results indicate that the lowest induction time for nucleation corresponded to hydrate crystallization from a solution with a THF concentration of 19 percent. This solution concentration matches with the stoichiometric percentage of THF in the crystalline hydrate. (Author)

Ganji, H.; Manteghian, M.; Sadaghiani Zadeh, K.; Torabi, F.

2005-07-01

70

Experimental investigations of active air bearings  

DEFF Research Database (Denmark)

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.

Santos, Ilmar; Morosi, Stefano

2012-01-01

71

Experimental Investigation of Particle Deagglomeration using Turbulence  

International Nuclear Information System (INIS)

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

2011-12-22

72

The experimental investigation of explosive opening switch  

International Nuclear Information System (INIS)

The explosive opening switch (EOS) used in explosive-driven magnetic-flux compression generator (EMCG) circuits was investigated. It is shown that (1) under certain conditions, the EOS voltage is hardly dependent on the size of the explosive and aluminium foil used in EOS; (2) with the explosive coated by an insulator pipe, the opening effect of EOS is better; (3) by use of EOS, a pulse with 5 kA current, 100 kV voltage and 250 ns risetime has been transferred into a resistance load. (author). 12 figs., 5 refs.

1996-01-01

73

???????????????? ??????????? ????? ? ???????????? ??????? Experimental investigation of wing with vortex generators ????????????????? ???????????? ????? ? ???????????? ??????  

Directory of Open Access Journals (Sweden)

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. ??? ????????????????? ???????????????? ????????????? ?? ??????? ????? ????? ??????????? ???????????? ??????????????? ????????? ????????? ?????. ? ???? ????? ??????????? ????? ????????? ??????? ? ???????????? ?????? ? ???? ???????? ?? ???????? ?????? ? ??????????????? ???????????????? ?????. ?????????????? ???????? ????????? ????? ? ???????????? ?????? ?? ???????? ?????? ??????????? ?? ???????? ???????????????? ????????????? ??? ????? ????? ????? ? ?????? ?? ??????? ????? ?????, ?????????? ???????????? ????????? ???? ? ??????? ????????? ?????????????? ??? ????? ????????? ?????????????.

?.?. ???????; ?.?. ????????

2010-01-01

74

Computational and experimental investigation of magnetized target fusion  

Energy Technology Data Exchange (ETDEWEB)

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

Sheehey, P.T.; Guzik, J.A.; Kirkpatrick, R.C.; Lindemuth, I.R.; Scudder, D.W.; Shlachter, J.S.; Wysocki, F.J.

1996-07-01

75

Experimental and Theoretical Investigations of Wet Flue Gas Desulphurisation  

DEFF Research Database (Denmark)

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

Kiil, SØren

1998-01-01

76

Experimental Investigation of Using Fuel Additives - Alcohol  

Directory of Open Access Journals (Sweden)

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

S.M. Fayyad

2010-01-01

77

Quantitative tear ferning. Methodologic and experimental investigations.  

UK PubMed Central (United Kingdom)

The reproducibility of different tear-ferning methods has been investigated by double tests on 122 subjects. Rough grading according to Rolando gives identical recovery in only 42 to 50%. Quantitative test (mm2 ferning per 1 microliter) of conjunctival fluid drawn with a glass rod according to Rolando gave a coefficient of variation of 99 to 128%. Aspiration with a quantitative pipette acc. to Norn 79%, and 55% for a standardized dilution (2.5 microliters of water) in the same pipette. The coefficient of variation was lower between tear samples aspirated through a thin capillary tube (1 mm = 0.5 microliter) from the lateral part of the tear meniscus (35%), and with a standardized tear volume (2.5 microliters) only 6.4%. Ferning is obstructed by ointment, fat emulsion dropped on the conjunctiva and mucous thread, but not by a glass slide rubber with stearin. A quantitative test with a capillary tube (2.5 microliters of aspirated lacrimal fluid) showed reduced ferning 30 sec after instillation of methylcellulose (2.5%) and arachis oil, and after expression of meibomian gland secretion. No significant alteration was observed after instillation of water or stimulation of the tear secretion by nasal inhalation of NH4OH.

Norn M

1988-04-01

78

The experimental investigation of concrete carbonation depth  

International Nuclear Information System (INIS)

Phenolphthalein indicator has traditionally been used to determine the depth of carbonation in concrete. This investigation uses the thermalgravimetric analysis (TGA) method, which tests the concentration distribution of Ca(OH)2 and CaCO3, while the X-ray diffraction analysis (XRDA) tests the intensity distribution of Ca(OH)2 and CaCO3. The Fourier transformation infrared spectroscopy (FTIR) test method detects the presence of C-O in concrete samples as a basis for determining the presence of CaCO3. Concrete specimens were prepared and subjected to accelerated carbonation under conditions of 23 deg. C temperature, 70% RH and 20% concentration of CO2. The test results of TGA and XRDA indicate that there exist a sharp carbonation front. Three zones of carbonation were identified according to the degree of carbonation and pH in the pore solutions. The TGA, XRDA and FTIR results showed the depth of carbonation front is twice of that determined from phenolphthalein indicator.

2006-01-01

79

Experimental investigation of a flapping wing model  

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-05-15

80

Measuring module for experimental investigations with polarized neutrons and nuclei  

International Nuclear Information System (INIS)

[en] The automatic system for servicing experimental investigations with polarized neutrons and nuclei is described. It consists of the SM-3 mini-computer and CAMAC equipment. The system permits to store a few time-of-flight spectra simultaneously, and to control the experimental set-up, as well as to control experimental conditions and to analyse the accumulated spectra

1987-01-01

 
 
 
 
81

Laboratory investigation of lightweight, low viscosity cementing spacer fluids  

Energy Technology Data Exchange (ETDEWEB)

The use of lightweight, low viscosity cementing spacer fluids was investigated using a large-scale apparatus that simulates actual field conditions. lightweight, low viscosity cementing spacer fluids appear to improve the total mud removal process by eroding away the mud filter cake and increasing the mobility of drilling fluid. To maximize total mud displacement, displacing fluids, (both spacer fluids and cementing slurries) had to be pumped as fast as possible. Laboratory results were independent of spacer volume. However, for long intervals of interest, such as those under field conditions, the volume of spacer fluid will probably have to be considered. 23 refs.

Haut, R.C.; Crook, R.J.

1981-01-01

82

Diagnostic Protocol Used in Central Disease Investigation Laboratory Dhaka, Bangladesh  

Directory of Open Access Journals (Sweden)

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.

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

2003-01-01

83

Reduction of friction in fluid transport: experimental investigation  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish 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 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 p (more) unto 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 opportunity 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 fl (more) uids 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.

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

2006-10-01

84

Experimental investigation of concrete-filled aluminum stub columns  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents an experimental investigation of concrete-filled aluminum tube columns. The structural performance of the concrete-filled aluminum tube columns was investigated using different concrete cylinder strengths of 40, 70 and 100 MPa. A series of tests was conducted to investigate the e...

Zhou, F; Young, B

85

Laboratory investigations of effective flow behavior in unsaturated heterogeneous sands  

DEFF Research Database (Denmark)

Two-dimensional unsaturated flow and transport through heterogeneous sand was investigated under controlled laboratory conditions. The unsaturated hydraulic conductivity of five homogeneous sands and three heterogeneous systems composed of these five sands was measured using a steady state flux controlled method. The heterogeneous sand systems were established in a laboratory tank for three realizations of random distributions of the homogeneous sands comprising a system of 207 grid cells. The water flux was controlled at the upper boundary, while a suction was applied at the lower boundary such that on the average a uniform pressure profile was established and gravity flow applied. Solute breakthrough curves measured at discrete points in the tank using time domain reflectometry, as well as dye tracer paths, showed that flow and transport took place in a very tortuous pattern where several grid cells were completely bypassed. The degree of tortuosity appeared to be dependent on the degree of saturation, as the tortuosity increased with decreasing saturation. Despite the tortuous flow patterns, we found that the effective unsaturated hydraulic conductivity as well as the retention curves for the three realizations of the heterogeneous sand were quite similar, thus suggesting that this type of heterogeneous flow system can be treated as an equivalent homogeneous medium characterized by effective parameters.

Wildenschild, Dorthe; HØgh Jensen, Karsten

1999-01-01

86

Laboratory investigation of lightweight, low-viscosity cementing spacer fluids  

Energy Technology Data Exchange (ETDEWEB)

The use of lightweight, low-viscosity cementing spacer fluids was investigated with a large-scale apparatus that simulates actual field conditions. Results show that various fluids can be effective when used as cementing spacer fluids. Lightweight, low-viscosity cementing spacer fluids appear to improve the total mud-removal process by eroding the mud filter cake and increasing the mobility of the drilling fluid. To maximize total mud displacement, displacing fluids (both spacer fluids and cementing slurries) had to be pumped as fast as possible. Even when turbulent flow could not be achieved by the cementing slurry, displacing at a maximum flow rate was more effective than plug flow displacement. Laboratory results were independent of spacer volume. However, for long intervals of interest, such as those under field conditions, the volume of spacer fluid probably should be considered.

Haut, R.C.; Crook, R.J.

1982-08-01

87

'BRUGIA TIMORI': Experimental Infection in Some Laboratory Animals.  

Science.gov (United States)

Experimental infection with Brugia timori of 7 birds (Meriones unguiculatus), 4 cats and 2 monkeys (Macaca fascicularis) is described. Although no microfilariae were detected by examining 20 microliter samples of tail blood of birds, adult worms were reco...

F. Partono D. T. Dennis Purnomo S. Atmosoedjono

1977-01-01

88

Laboratory and numerical investigation of transport processes occurring above and within a saltwater wedge.  

UK PubMed Central (United Kingdom)

Salt wedges divide coastal groundwater flow regime into two distinct regions that include a freshwater region above the saltwater-freshwater interface and a saltwater region below the interface. Several recent studies have investigated saltwater transport in coastal aquifers and the associated flow and mixing processes. Most of these studies, however, have either focused on studying the movement of salt wedge itself or on studying contaminant transport processes occurring above the wedge. As per our knowledge, so far no one has completed laboratory experiments to study contaminant transport processes occurring within a saltwater wedge. In this study, we completed laboratory experiments to understand contaminant transport dynamics occurring within a saltwater wedge. We used a novel experimental approach that employed multiple neutral-density tracers to map and compare the mixing and transport processes occurring above and within a saltwater wedge. The experimental data were simulated using SEAWAT, and the model was used to further investigate the saltwater flow and transport dynamics within a wedge. The laboratory data show that the transport rates active within the wedge are almost two orders of magnitude slower than the transport rates active above the wedge for the small-scale experimental system which is characterized by very low level of mixing. The numerical results, however, postulate that for large-scale systems involving higher levels of mixing (or dispersion) the transport rate active within the wedge could be comparable or even higher than the rates active above the wedge. More field or laboratory studies completed under high dispersion conditions are needed to further test this hypothesis.

Chang SW; Clement TP

2013-04-01

89

[Laboratory investigations in acute intoxications--what makes sense?].  

UK PubMed Central (United Kingdom)

Clinical symptoms in acute intoxications are often nondescript and unspecific for a definite diagnosis. This makes laboratory investigations necessary in order to initiate supportive measures and to confirm or discard the diagnosis of an acute intoxication. For toxicological analyses immunoassays as well as chromatographic methods are applied. Unfortunately, not all potential toxic compounds can be detected by these methods, e.g. ethanol and metals (including lithium) cannot be seen. The sample materials for toxicological analyses are on one hand blood for the quantitative determination of a distinct compound and on the other hand urine for toxicological screening procedures. Whenever the clinical situation does not exclude intoxication, a toxicological screening should be carried out. The comprehensiveness of the toxicological screening is dependent on the anamnesis and the clinical symptoms of the patient and should also depend on the therapeutic options for the various differential diagnoses. A specific quantitative determination of the toxic compound is recommended for acetaminophen, lithium, amanitine (intoxications with death cap), colchicine, alcohols and glycols, carbon monoxide and cyanide.

Rentsch KM

2009-05-01

90

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Hall, Adam C.; Harrington, Mary E.

91

Experimental investigation of surface wave propagation in collisional plasma columns  

Science.gov (United States)

An experimental study of surface wave propagation in a low-pressure collisional plasma column generated by the wave itself is presented. It is experimentally demonstrated that the maximum wave number value attainable decreases with increasing collisional effects. The separate effects of collisions and radial plasma inhomogeneity on the wave propagation are investigated. Some practical considerations concerning the correct measurement of the phase and attenuation diagrams are pointed out.

Dias, F. M.; Tatarova, E.; Henriques, J.; Ferreira, C. M.

1999-03-01

92

Experimental method for investigating helium effects in irradiated vanadium  

Energy Technology Data Exchange (ETDEWEB)

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

Smith, D.L.; Matsui, H.; Greenwood, L.; Loomis, B.

1987-10-01

93

Software to Enhance Hands-On Laboratory Experimentation  

Science.gov (United States)

This presentation from MATEC explains the transition from using software to getting hands-on experience in a lab. The laboratory setting in technology related courses is an integral part of the learning experience for the student. It takes the theory that is being learned in the lecture and applies that theory. The text books that are used in the lecture include a copy of either Multi Sim or Electronic Workbench. The software gives the student the ability to "build" the circuits that are under study without the hardware that is found in the lab. The students at Grambling State University are not utilizing the software in the beginning level classes. The students must start utilizing the software earlier in the educational career. To accomplish this, the students are starting to complete the lab assignments with software before going to the lab. By doing this, the students will know what to expect before starting lab. This can and hopefully will remove some confusion that the beginner level circuit student has when constructing a circuit. The next step to improving and enhancing the laboratory experience for the student is to add a computer system to each laboratory station. Each system will contain software and hardware that will connect the test instruments to the computer and perform a multitude of analysis functions. The software that has stimulated some interest is MatLab. MatLab includes curriculum for some of the following: digital signal processing, digital image processing, digital filters, signals and systems, speech processing, computer-controlled systems, applied digital signal processing, dynamic modeling of engineering systems, and continuous-time linear systems. In conclusion, the learning invention for this laboratory is to bring together the lecture and lab through the implementation of software and hardware. This was part of the Learning Invention Labs that MATEC held. Visit the MATEC.org homepage for more information.

Flinders, Shirley

2013-01-01

94

Requirements for Real-Time Laboratory Experimentation over the Internet.  

Science.gov (United States)

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…

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

95

Laboratory investigation of crushed salt consolidation and fracture healing  

Energy Technology Data Exchange (ETDEWEB)

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

1987-01-01

96

Experimental Investigation of the Integral Constant in Steady Flow Conditions  

Directory of Open Access Journals (Sweden)

Full Text Available An elaborate experimental system was designed and built in the Hydraulics Laboratory of Civil Engineering Department of Dokuz Eylul University, in order to study the velocity distribution by means of an Ultrasonic Velocity Profiler (UVP) over rough bed at different flow rates. The UVP which has the advantage of providing instantaneous velocity distribution was also used to measure the bed elevations. The shear velocity, u* and the integral constant, Br were calculated from the mean velocity profiles by applying the Clauser Method and compared with those given in the relevant literature.

Gökçen Bombar; ?ükrü Mehmet Güney

2010-01-01

97

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.

1982-01-01

98

Experimental investigation and model verification for a GAX absorber  

Energy Technology Data Exchange (ETDEWEB)

In the ammonia-water generator-absorber heat exchange (GAX) absorption heat pump, the heat and mass transfer processes which occur between the generator and absorber are the most crucial in assuring that the heat pump will achieve COPs competitive with those of current technologies. In this study, a model is developed for the heat and mass transfer processes that occur in a counter-current vertical fluted tube absorber (VFTA) with inserts. Correlations for heat and mass transfer in annuli are used to model the processes in the VTA. Experimental data is used to validate the model for three different insert geometries. Comparison of model results with experimental data provides insight into model corrections necessary to bring the model into agreement with the physical phenomena observed in the laboratory.

Palmer, S.C. [Naval Academy, Annapolis, MD (United States). Mechanical Engineering Dept.; Christensen, R.N. [Ohio State Univ., Columbus, OH (United States). Mechanical Engineering Dept.

1996-12-31

99

Laboratory Investigation of Hydrated Lime as an Antistripping Additive.  

Science.gov (United States)

The purpose of this laboratory study was to determine the effectiveness of hydrated lime as an antistripping additive when used in bituminous mixes incorporating aggregates frequently used in such mixes in Virginia. The application of 1% hydrated lime to ...

G. W. Maupin

1983-01-01

100

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

Energy Technology Data Exchange (ETDEWEB)

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%.

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

2002-06-03

 
 
 
 
101

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

International Nuclear Information System (INIS)

[en] 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%

2002-01-01

102

An Experimental Investigation of Secure Communication With Chaos Masking  

CERN Document Server

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.

Dhar, Sourav

2007-01-01

103

- El rol de la enfermera en un departamento de Cirugía Experimental (The nurse role in an experimental surgery laboratory  

Directory of Open Access Journals (Sweden)

Full Text Available Los esfuerzos de enfermería en estos últimos años se han centrado en buscar la autonomía y conseguir la independencia de la profesión, tanto en el ejercicio profesional como en el desarrollo científico, lo que ha facilitado su apertura a otros campos del conocimiento, como es la investigativa. La Cirugía experimental constituye una disciplina muy importante de las ciencias biomédicas por las amplias posibilidades que ofrece en el campo de la investigación así como en el adiestramiento de los futuros cirujanos y la enseñanza de pre y postgrado y la dotación de personal en este es vital si se desea mantener esa actividad investigativa que permita resolver problemas de la clínica o susceptibles de la propia investigación, no dejando a un lado la docencia, así como la prestación de servicios a otros departamentos, instituciones, etc., por lo que es imprescindible contar con la presencia de una enfermera, o varias, en dependencia de la cantidad de quirófanos con que cuenta el Dpto. o Laboratorio en cuestión. Tal como en el área clínica, la enfermera en el departamento o laboratorio de cirugía experimental ejerce las tres etapas del perioperatorio, con la ayuda del equipo de trabajo. Estas son: preoperatorio, transoperatorio y postoperatorio. El objetivo de este trabajo es dar a conocer la importancia de la enfermera en el trabajo de un departamento o laboratorio de cirugía experimental. Un centro, departamento o laboratorio de Cirugía experimental que no cuente con una enfermera dentro de su dotación de personal, no podrá realizar un buen trabajo, pues en la atención quirúrgica la enfermera es tan imprescindible como el cirujano, con funciones independientes y a la vez complementarias The nursing efforts during the last few years have been directed specifically in finding autonomy and independence in the profession, not only professionally, but also in the scientific development. It has facilitated its spreading to many fields of knowledge, as it is the case of investigation. Experimental surgery is a very important discipline within the biomedical sciences due to the possibilities it offers in the field of research in training future surgeons and in teaching graduates and non graduates . Personnel working here are quite important to keep the research projects, so as to solve problems related to clinics or associated with investigation. All these aspects should be kept in mind but without letting aside teaching and assistance to other departments, institutions, etc. Having this in mind it is necessary to have a nurse or more than one, if possible, depending on the number of surgeons there exist in the department or laboratory. The aim of this research is to give information on the importance of nurses as collaborators in a department or laboratory of experimental surgery. A department of experimental surgery without a nurse, as part of the staff, will never be able to carry out a good job, because they are as indispensable as surgeons, with independent and complementary functions typical of their profession.

Lic. Ileana Macías Hernández; Dr. Víctor M. Rodríguez Sosa; y Enf. María Victoria Ponce Ramírez

2006-01-01

104

El rol de la enfermera en un departamento de Cirugía Experimental (The nurse role in an experimental surgery laboratory)  

Directory of Open Access Journals (Sweden)

Full Text Available Los esfuerzos de enfermería en estos últimos años se han centrado en buscar la autonomía y conseguir la independencia de la profesión, tanto en el ejercicio profesional como en el desarrollo científico, lo que ha facilitado su apertura a otros campos del conocimiento, como es la investigativa. La Cirugía experimental constituye una disciplina muy importante de las ciencias biomédicas por las amplias posibilidades que ofrece en el campo de la investigación así como en el adiestramiento de los futuros cirujanos y la enseñanza de pre y postgrado y la dotación de personal en este es vital si se desea mantener esa actividad investigativa que permita resolver problemas de la clínica o susceptibles de la propia investigación, no dejando a un lado la docencia, así como la prestación de servicios a otros departamentos, instituciones, etc., por lo que es imprescindible contar con la presencia de una enfermera, o varias, en dependencia de la cantidad de quirófanos con que cuenta el Dpto. o Laboratorio en cuestión. Tal como en el área clínica, la enfermera en el departamento o laboratorio de cirugía experimental ejerce las tres etapas del perioperatorio, con la ayuda del equipo de trabajo. Estas son: preoperatorio, transoperatorio y postoperatorio. El objetivo de este trabajo es dar a conocer la importancia de la enfermera en el trabajo de un departamento o laboratorio de cirugía experimental. Un centro, departamento o laboratorio de Cirugía experimental que no cuente con una enfermera dentro de su dotación de personal, no podrá realizar un buen trabajo, pues en la atención quirúrgica la enfermera es tan imprescindible como el cirujano, con funciones independientes y a la vez complementarias The nursing efforts during the last few years have been directed specifically in finding autonomy and independence in the profession, not only professionally, but also in the scientific development. It has facilitated its spreading to many fields of knowledge, as it is the case of investigation. Experimental surgery is a very important discipline within the biomedical sciences due to the possibilities it offers in the field of research in training future surgeons and in teaching graduates and non graduates . Personnel working here are quite important to keep the research projects, so as to solve problems related to clinics or associated with investigation. All these aspects should be kept in mind but without letting aside teaching and assistance to other departments, institutions, etc. Having this in mind it is necessary to have a nurse or more than one, if possible, depending on the number of surgeons there exist in the department or laboratory. The aim of this research is to give information on the importance of nurses as collaborators in a department or laboratory of experimental surgery. A department of experimental surgery without a nurse, as part of the staff, will never be able to carry out a good job, because they are as indispensable as surgeons, with independent and complementary functions typical of their profession.

Ileana Macías Hernández; Víctor M. Rodríguez Sosa; María Victoria Ponce Ramírez

2006-01-01

105

Experimental apparatus for tritium permeation studies in tritium process laboratory  

International Nuclear Information System (INIS)

[en] An experimental apparatus has been developed to carry out tritium permeation experiments for candidate first-wall materials subjected to a high flux of low energy tritium ions, and installed in a glovebox. The experimental apparatus consists of five main systems; (1) a tritium ion source with energies variable from 20 to 1400 eV, (2) a main chamber system for direction an ion beam onto a heated target and for measuring various implantation-related experimental parameters by means of SIMS and AES, (3) a downstream system for measuring the permeated tritium through the target specimen by means of QMS, (4) a tritium supply and recovery system and (5) evacuation system. Operational tests with the system have yielded deuterium ion-beam with more than 90% deuterons and intensities from 2 x 1015 D+/cm2s at 200 eV to greater than 3 x 1015 D+/cm2s at 1000 eV. The energy width of the ion beam was about 10% of the beam energy ranging from 100 to 1400 eV. Baseline pressure as low as 9 x 0-9 Torr and 1 x 10-9 Torr have been achieved in the main chamber and downstream system, respectively

1988-01-01

106

Experimental apparatus for tritium permeation studies in tritium process laboratory  

Energy Technology Data Exchange (ETDEWEB)

An experimental apparatus has been developed to carry out tritium permeation experiments for candidate first-wall materials subjected to a high flux of low energy tritium ions, and installed in a glovebox. The experimental apparatus consists of five main systems; (1) a tritium ion source with energies variable from 20 to 1400 eV, (2) a main chamber system for direction an ion beam onto a heated target and for measuring various implantation-related experimental parameters by means of SIMS and AES, (3) a downstream system for measuring the permeated tritium through the target specimen by means of QMS, (4) a tritium supply and recovery system and (5) evacuation system. Operational tests with the system have yielded deuterium ion-beam with more than 90% deuterons and intensities from 2 x 10/sup 15/ D/sup +//cm/sup 2/s at 200 eV to greater than 3 x 10/sup 15/ D/sup +//cm/sup 2/s at 1000 eV. The energy width of the ion beam was about 10% of the beam energy ranging from 100 to 1400 eV. Baseline pressure as low as 9 x 0/sup -9/ Torr and 1 x 10/sup -9/ Torr have been achieved in the main chamber and downstream system, respectively.

Okuno, K.; O' Hira, S.; Yoshida, H.; Naruse, Y.; Hirata, S.; Misumi, M.

1988-09-01

107

Minimum Experimental Standards in the Laboratory Search for Gravity Effects  

International Nuclear Information System (INIS)

Peer-reviewed reports of experimental modifications of gravity over rotating superconductors (Podkletnov, 1992), or of a weight increase during cool-down of superconductors (Reiss, 2003), have stimulated considerable recent discussion. Precise descriptions of sample composition, ancillary apparatus and balance specifications were not given by Podkletnov. Accordingly, a carefully-designed replication (Hathaway, 2003) could not confirm the experimental findings possibly because detailed information was unavailable. On the other hand Tajmar et al. (Tajmar, 2005) failed to replicate previous results due to lack of serious analysis of weight measurements of solids in atmosphere and subject to buoyancy and wetting forces. Also an acceptable measuring technique and a detailed analysis of the sample's temperature excursions versus time were not performed. Both examples clearly indicate that minimum standards of experimental precision, accounting for boundary conditions, error analysis and thorough reporting of the experiment are necessary to distinguish a true anomaly from prosaic explanations and artefacts. We will discuss some types of errors that can occur and how standards of analysis and reporting should be improved to allow others a thorough physical understanding

2006-01-20

108

Minimum Experimental Standards in the Laboratory Search for Gravity Effects  

Science.gov (United States)

Peer-reviewed reports of experimental modifications of gravity over rotating superconductors (Podkletnov, 1992), or of a weight increase during cool-down of superconductors (Reiss, 2003), have stimulated considerable recent discussion. Precise descriptions of sample composition, ancillary apparatus and balance specifications were not given by Podkletnov. Accordingly, a carefully-designed replication (Hathaway, 2003) could not confirm the experimental findings possibly because detailed information was unavailable. On the other hand Tajmar et al. (Tajmar, 2005) failed to replicate previous results due to lack of serious analysis of weight measurements of solids in atmosphere and subject to buoyancy and wetting forces. Also an acceptable measuring technique and a detailed analysis of the sample's temperature excursions versus time were not performed. Both examples clearly indicate that minimum standards of experimental precision, accounting for boundary conditions, error analysis and thorough reporting of the experiment are necessary to distinguish a true anomaly from prosaic explanations and artefacts. We will discuss some types of errors that can occur and how standards of analysis and reporting should be improved to allow others a thorough physical understanding.

Reiss, H.; Hathaway, G.

2006-01-01

109

Experimental investigation on burning characteristics of blended coals  

Energy Technology Data Exchange (ETDEWEB)

The results of experimental investigation on burning characteristics for four groups of blended coals of various ranks are: 1)the ignition characteristic for the blended coals approaches that of the coal which is easiest to ignite; and 2)the burnout characteristic is closest to the coal which has the slowest burnout. 6 figs., 2 tabs.

Hou, D.Q.; Feng, J.M.; Chen, C.Y. [Harbin Power System Engineering and Research Institute, Harbin (China)

1995-12-31

110

Contract design and insurance fraud : an experimental investigation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper investigates the impact of insurance contract design on the behavior of filing fraudulent claims in an experimental setup. We test how fraud behavior varies for insurance contracts with full coverage, a straight deductible or variable premiums (bonus-malus contract). In our experiment, fi...

Lammers, Frauke; Schiller, Jörg

111

Experimental Investigations of Elastic Tail Propulsion at Low Reynolds Number  

CERN Document Server

A simple way to generate propulsion at low Reynolds number is to periodically oscillate a passive flexible filament. Here we present a macroscopic experimental investigation of such a propulsive mechanism. A robotic swimmer is constructed and both tail shape and propulsive force are measured. Filament characteristics and the actuation are varied and resulting data are quantitatively compared with existing linear and nonlinear theories.

Yu, T S; Hosoi, A E; Yu, Tony S.; Lauga, Eric

2006-01-01

112

Investigation of Sulfate Attack by Experimental and Thermodynamic Means  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This work investigates sulfate attack in complex sulfate environments by exposing different binder types to various sulfate solutions and comparing predicted phase and volume changes with experimental data. The most important aspects of this work can be grouped in three topic...

Kunther, Wolfgang

113

Experimental investigation of a manifold heat-pipe heat exchanger  

International Nuclear Information System (INIS)

Results of experimental investigations of a heat exchanger on a manifold water heat pipe are given. An analysis is made of the temperature distribution along the heat-transfer agent path as a function of the transferred heat power. The influence of the degree of filling with the heat transfer agent on the operating characteristics of the construction is considered

1995-01-01

114

Transparency and Disclosing Conflicts of Interest: An Experimental Investigation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Conflicts of interest have always been a problem in situation of advice giving between a client and a better informed advisor. Economic theory captures this matter by means of principal-agent models or games of information transmission. We experimentally investigate how different degrees of transpar...

Inderst, Roman; Rajko, Alexander; Ockenfels, Axel

115

Experimental Investigation into Electrical Discharge Machining of Stainless Steel 304  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 surf...

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

116

Experimental investigation of stimulated Brillouin scattering in an amplifying medium  

Energy Technology Data Exchange (ETDEWEB)

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

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

1985-09-01

117

Experimental and numerical investigation on two-phase flow instabilities  

Energy Technology Data Exchange (ETDEWEB)

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)

Ruspini, Leonardo Carlos

2013-03-01

118

Numerical and experimental investigation of vortical flow-flame interaction  

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-02-01

119

Analytical and experimental investigations of rock cutting using polycrystalline diamond compact drag cutters  

Energy Technology Data Exchange (ETDEWEB)

The development of analytical techniques describing rock fracture during drilling would make possible a more rational approach to the design of drills and bits. This paper describes progress toward this goal based on finite element and experimental investigations of the rock cutting process for a single drag bit. The material model used for rock in the analysis includes fracturing due to both tensile and shear stresses. Results capture the essential features of drilling observed in the laboratory and indicate expected differences between unconfined laboratory tests and downhole drilling. 7 refs.

Swenson, D.V.; Wesenberg, D.L.; Jones, A.K.

1981-01-01

120

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

Science.gov (United States)

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.

Adam C. Hall (Smith College;); Mary E. Harrington (Smith College;)

2003-11-01

 
 
 
 
121

[Hyperfine experimental investigation of zirconia ceramics]. [Annual progress report 20  

Energy Technology Data Exchange (ETDEWEB)

This research program has encompassed a broad investigation of microscopic structure and point defect properties in insulating materials and some recent exploratory work on semiconductors. The major experimental technique is perturbed angular correlation (PAC) spectroscopy. Our research provides information about the microscopic structure, nucleation, and equilibrium of structural phases in materials under investigation. We have studied phase equilibria in monoclinic, tetragonal, and cubic zirconia in the past and have recently begun more detailed investigation of high-temperature anomalies in monoclinic zirconia and tetragonal stabilized zirconia. We also have found a number of instances where the indium PAC probe has detected subtle phase changes, small precipitate formation, and other phase behavior that are difficult to detect by conventional diffraction methods. The PAC experimental technique is described briefly in section 2, and recent research is reviewed in section 3.

1992-09-01

122

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

Energy Technology Data Exchange (ETDEWEB)

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

Vagin, S.P.

1995-05-01

123

An experimental investigation into lateral pipeline/soil interaction  

Energy Technology Data Exchange (ETDEWEB)

An experimental research program using centrifuge modelling was undertaken by NOVA Gas Transmission Limited in 1991 to study the load transfer behaviour of buried pipelines subjected to lateral soil movement. Specific objectives were to investigate the effects of pipeline soil cover, ditch width, interaction rate, preconsolidation stress of the soil, and different backfill types. In this report new experimental test results for a prototype 0.95m diameter pipeline subjected to lateral soil movement under a 0.8m cover depth were discussed, and compared with current pipeline/soil interaction analysis methods, and with conventional geotechnical analysis results. 10 refs., 2 tabs., 5 figs.

Paulin, M. J.; Phillips, R.; Clark, J. I. [Memorial Univ. of Newfoundland, St. John`s, NF (Canada). Centre for Cold Ocean Resources Engineering; Boivin, R. [NOVA Gas Transmission Limited, Calgary, AB (Canada)

1996-12-31

124

Experimental investigation of laser-assisted thermoplastic tape consolidation  

Energy Technology Data Exchange (ETDEWEB)

An experimental investigation of a novel approach for manufacturing of thermoplastic matrix composites, is described. The technique is based on using laser energy as the focused heat source to melt the matrix material for subsequent consolidation, and appears to be particularly suited for thermoplastic filament winding opertions. An experimental set up is defined to produce multi ply rings, and the feasibility of this technique is demonstrated by discussing several samples that were produced using Ryton AC40-60 prepreg tapes. The quality of consolidation is examined through cross-sectional micrographs. 12 references.

Beyeler, E.; Phillips, W.; Guseri, S.I.

1988-01-01

125

FOSS Variables FOSS Lifeboat Investigation: Developing Investigable Question, Investigation (Experimentation), and Communicating Results  

Science.gov (United States)

This activity is an extension of the FOSS Variables Lifeboat investigation. Students choose a lifeboats variable to investigate, write up an experiment based on the variable to be tested, test the variable, and create a lifeboats investigation poster to share their results.

Walvatne, Amy

126

Experimental techniques for the investigation of coupled phenomena in geomaterials  

Directory of Open Access Journals (Sweden)

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

Romero E.

2010-01-01

127

Experimental and numerical investigation of orbital atherectomy: absence of cavitation  

Directory of Open Access Journals (Sweden)

Full Text Available A definitive, quantitative investigation has been performed to determine whether orbital atherectomy gives rise to cavitation. The investigation encompassed a synergistic interaction between in vitro experimentation and numerical simulation. The experimentation was performed in two independent fluid environments: 1) a transparent tube having a diameter similar to that of the superficial femoral artery and 2) a large, fluid-filled, open-topped container. All of the experimental and simulation work was based on the geometric model of the Diamondback 360 atherectomy device (Cardiovascular Systems, Inc., St. Paul, MN). Rotational speeds ranged from 80,000 to 214,000 rpm. The presence or absence of cavitation in the experiments was assessed by means of high-speed photography. The photographic images clearly display the fact that there was no cavitation. Flow visualization revealed the presence of fluid flows driven by pressure gradients created by the geometry of the rotating crown. The numerical simulations encompassed the fluid environments and the operating conditions of the experiments. The key result of the numerical simulation is that the minimum fluid pressure due to the rotational motion was approximately 50 times greater than the saturation vapor pressure of the fluid. Since the onset of cavitation requires that the fluid pressure falls below the saturation vapor pressure, the computational outcome strongly supports the experimental findings.

Reza Ramazani-Rend; Srikar Chelikani; Ephraim M. Sparrow; John P. Abraham

2010-01-01

128

Experimental investigation of contact resistance across pressed lead and aluminum  

Energy Technology Data Exchange (ETDEWEB)

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.

Smith, A.C.

2000-03-22

129

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.

2000-01-01

130

Experimental and theoretical investigation of high gradient acceleration  

International Nuclear Information System (INIS)

[en] 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

1993-01-01

131

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)

2009-01-01

132

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

International Nuclear Information System (INIS)

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

2009-01-01

133

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

CERN Multimedia

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.

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

2010-01-01

134

Application of Different Mixing Systems for the Batch Cultivation of the Saccharomyces cerevisiae. Part I: Experimental Investigations and Modelling  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Experimental investigations in different mixing conditions (impulse and vibromixing) in a Saccharomyces cerevisiae batch cultivation are presented in this paper. The investigation is carried out in a 5 l laboratory bioreactor (working volume 3 l). Mathematical models of the process for the two mixin...

Uldis Viesturs; Andrejs Berzins; Juris Vanags; Stoyan Tzonkov; Tatiana Ilkova; Mitko Petrov; Tania Pencheva

135

Investigations of Solar Prominence Dynamics Using Laboratory Simulations  

International Nuclear Information System (INIS)

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

2008-01-01

136

Investigations of Solar Prominence Dynamics Using Laboratory Simulations  

Energy Technology Data Exchange (ETDEWEB)

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

Paul M Bellan

2008-05-28

137

Experimental assessment of hygrothermal performance of an interior thermal insulation system using a laboratory technique simulating on-site conditions  

Energy Technology Data Exchange (ETDEWEB)

A laboratory technique simulating on-site conditions is used for hygrothermal performance assessment of two building envelopes. Interior thermal insulation system on the basis of hydrophilic mineral wool which is applied on two common load bearing structures is analyzed. Sufficiently large specimens of studied building envelopes are exposed to difference climate conditions very close to reality. Monitoring of moisture and temperature fields in the investigated structures is carried out using laboratory measuring technology. Experimental results give evidence that the hygrothermal performance of both tested building envelopes is satisfactory. (author)

Pavlik, Zbysek; Cerny, Robert [Department of Building Materials, Faculty of Civil Engineering, Czech Technical University in Prague, Thakurova 7, 166 29 Prague 6 (Czech Republic)

2008-07-01

138

Experimental Investigation into Electrical Discharge Machining of Stainless Steel 304  

Directory of Open Access Journals (Sweden)

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.

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

2011-01-01

139

HCN2+ dication spectroscopy: theoretical and experimental investigations  

International Nuclear Information System (INIS)

[en] The present work combines experimental and theoretical investigations of HCN2+ to investigate the spectroscopy and dissociation dynamics of this dication. Its spectrum is a complex blend of overlapping features, consistent with theoretical calculations showing that the low-lying electronic states of HCN2+ exhibit Renner-Teller and vibronic interactions. The double ionisation spectra are dominated by C-N stretching excitations for all the electronic states investigated. Long-lived HCN2+ ions are observed and are believed to be in low vibrational levels of the X 3?- and/or 1? and/or 1?+ electronic states; some have metastable lifetimes of about 25 ns. The formation of H+ + CN+ products is attributed to predissociation by the lowest 3A' component resulting from a conical intersection between the X 3?- and 3? states. The overall predissociation processes involve vibronic, Renner-Teller and spin-orbit couplings between several electronic states of HCN2+

2005-03-14

140

An experimental investigation of a household size trigeneration  

Energy Technology Data Exchange (ETDEWEB)

A household size trigeneration based on a small-scale diesel engine generator set is designed and realized in laboratory. Experimental tests are carried out to evaluate the performance and emissions of the original single generation (diesel engine generator); and the performances of the whole trigeneration including the diesel generator within the trigeneration system, the heat exchangers which are used to recover heat from engine exhaust, the absorption refrigerator which is driven by the exhaust heat; and the emissions from the whole trigeneration. Comparisons of the test results of two generations are also performed. The test results show that the total thermal efficiency of trigeneration reaches to 67.3% at the engine full load, comparing to that of the original single generation 22.1% only. Within the range of engine loads tested, the total thermal efficiencies of trigeneration are from 205% to 438% higher than that of the thermal efficiency of single generation. The CO{sub 2} emission per unit (kWh) of useful energy output from trigeneration is 0.401kg CO{sub 2}/kWh at the engine full load, compared to that of 1.22kg CO{sub 2}/kWh from single generation at the same engine load. Within the range of engine loads tested, the reductions of CO{sub 2} emission per unit (kWh) of trigeneration output are from 67.2% to 81.4% compared to those of single generation. The experimental results show that the idea of realizing a household size trigeneration is feasible; the design and the set-up of the trigeneration is successful. The experimental results show that the innovative small-scale trigeneration is able to generate electricity, produce heat and drive a refrigeration system, simultaneously from a single fuel (diesel) input. (author)

Lin, Lin [Nanning College for Vocational Technology, Nanning, Guangxi 530003 (China); Wang, Yaodong; Zeng, Shengchuo; Huang, Jincheng; He, Yunxin; Huang, Xiaodong [Mechanical Engineering College, Guangxi University, Nanning, Guangxi 530004 (China); Al-Shemmeri, Tarik; Ruxton, Tom; Turner, Stuart [Faculty of Computing, Engineering and Technology, Staffordshire University, Stafford ST18 0AD (United Kingdom)

2007-02-15

 
 
 
 
141

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.

1991-01-01

142

Experimental Investigation of the Rayleigh-Taylor Instability  

Science.gov (United States)

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

White, Jeremy

143

Experimental investigation of scroll based organic Rankine cycles  

Energy Technology Data Exchange (ETDEWEB)

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.

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

144

Experimental and theoretical investigations of diffraction enhanced imaging  

Energy Technology Data Exchange (ETDEWEB)

This contribution investigates the effect on the imaging contrast of the small angle scattering and of the rocking curve in the entire angular range. We show that based on the small angle scattering properties, the reflectivity of the crystal analyzer and the rocking curve of the monochromator-analyzer, in a diffraction enhanced imaging (DEI) experimental setup the contrast of the image collected at the top of the rocking curve is always higher than that of the apparent absorption image. Moreover, our experimental data confirm that the quality of a refraction image is superior to a refraction-like image. In order to understand the observed behavior we introduce and discuss the contribution of a new term in the classical DEI equation.

Wang Junyue [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Zhu Peiping [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)], E-mail: zhupp@ihep.ac.cn; Yuan Qingxi; Huang Wanxia [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Shu Hang [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Chen Bo [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Li Enrong [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Liu Yijin; Hu Tiandou; Wu Ziyu [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

2007-09-21

145

Experimental investigation of the reciprocating ball pump (RBP).  

Science.gov (United States)

This paper presents experimental investigations of a novel miniature reciprocating ball pump (RBP) as a potential infusion pump or drug delivery system. The objectives of this study are to validate the RBP's operational principle and to evaluate its performance. In the tests, the basic functionality of the pump has been established at different pumping frequencies ranging from 1.667 Hz (100 rpm) to 4.167 Hz (250 rpm) against different pressure heads ranging from 0 mmH(2)O and 100 mmH(2)O. In addition, experimental results show that the RBP can deliver a higher flow rate with a volumetric efficiency of 120% as compared to a conventional single acting reciprocating pump running under the same operating conditions. PMID:22205041

Lieu, C F; Chan, W K; Ooi, K T

2011-12-26

146

Experimental investigation of the reciprocating ball pump (RBP).  

UK PubMed Central (United Kingdom)

This paper presents experimental investigations of a novel miniature reciprocating ball pump (RBP) as a potential infusion pump or drug delivery system. The objectives of this study are to validate the RBP's operational principle and to evaluate its performance. In the tests, the basic functionality of the pump has been established at different pumping frequencies ranging from 1.667 Hz (100 rpm) to 4.167 Hz (250 rpm) against different pressure heads ranging from 0 mmH(2)O and 100 mmH(2)O. In addition, experimental results show that the RBP can deliver a higher flow rate with a volumetric efficiency of 120% as compared to a conventional single acting reciprocating pump running under the same operating conditions.

Lieu CF; Chan WK; Ooi KT

2012-10-01

147

Experimental investigation of axial fan erosion and performance degradation  

Energy Technology Data Exchange (ETDEWEB)

An experimental investigation was conducted to study the effects of sand ingestion on an axial fan with an upstream guide vane (contra-whirl). The experimental work was divided into two types of testing. Firstly, local injection tests were carried out to generate qualitative erosion patterns in order to validate a trajectory code. Secondly, global sand injection tests were carried out in order to assess the geometry deterioration and the subsequent degradation in the axial fan aerodynamic characteristics. Two types of particle were used; a narrow size bandwidth sand (150 - 300 {mu}m) and MIL-E5007E sand (0 - 1000 mm). In all sand injection tests the fan operated near design point at a constant speed of rotation. (author)

Ghenaiet, A. [Polytechnic School, Algiers (Algeria). Thermal Power Laboratory; Tan, S.C. [Wichita State University, Kansas (United States); Elder, R.L. [PCA Engineering, Bedford (United Kingdom)

2004-11-01

148

Experimental investigation of radiation transmission through a water spray  

Energy Technology Data Exchange (ETDEWEB)

Radiation attenuation by a water spray is experimentally investigated. Spectral transmissivity measurements are performed between 1000 and 7000cm{sup -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.

Parent, G. [Laboratoire d' Energetique et de Mecanique Theorique and Appliquee (LEMTA), CNRS UMR 7563, Faculte des Sciences et Techniques BP 239-54506 Vandoeuvre Cedex (France); Boulet, P. [Laboratoire d' Energetique et de Mecanique Theorique and Appliquee (LEMTA), CNRS UMR 7563, Faculte des Sciences et Techniques BP 239-54506 Vandoeuvre Cedex (France)]. E-mail: Pascal.Boulet@lemta.uhp-nancy.fr; Gauthier, S. [Laboratoire d' Energetique et de Mecanique Theorique and Appliquee (LEMTA), CNRS UMR 7563, Faculte des Sciences et Techniques BP 239-54506 Vandoeuvre Cedex (France); Blaise, J. [Laboratoire d' Energetique et de Mecanique Theorique and Appliquee (LEMTA), CNRS UMR 7563, Faculte des Sciences et Techniques BP 239-54506 Vandoeuvre Cedex (France); Collin, A. [Laboratoire d' Energetique et de Mecanique Theorique and Appliquee (LEMTA), CNRS UMR 7563, Faculte des Sciences et Techniques BP 239-54506 Vandoeuvre Cedex (France)

2006-01-15

149

Geoengineering Characterization of Welded Tuffs from Laboratory and Field Investigations.  

Science.gov (United States)

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 Mounta...

R. M. Zimmerman F. B. Nimick M. P. Board

1984-01-01

150

A laboratory investigation of land and sea breeze regimes  

Energy Technology Data Exchange (ETDEWEB)

A laboratory experiment has been performed to simulate land and sea breeze (LSB) flows occurring in the atmosphere in the absence of a mean geostrophic wind (pure breeze). The experiment has been carried out in a temperature-controlled water tank. Three CCD video cameras have been utilised to acquire the images of the flow field produced by temperature gradients. Particle tracking velocimetry (PTV) is applied to evaluate the velocity field in a vertical section of the tank illuminated by a laser light sheet. Furthermore, temperature-time histories have been carried out by means of a thermocouple array positioned along a vertical profile. The system has been employed to generate and analyse the global circulation and the dynamics of the sea breeze front. (orig.)

Cenedese, A.; Miozzi, M.; Monti, P. [Dipt. di Idraulica, Univ. di Roma ' ' La Sapienza' ' (Italy)

2000-12-01

151

Results of laboratory investigations of gas and coal outbursts  

Energy Technology Data Exchange (ETDEWEB)

On a laboratory testing stand incorporating a pipe with a briquette of fine coal formed inside it, three series of experiments were carried out using nitrogen or carbon dioxide as gas. The initial condition necessary to produce an outburst was created in such a way that at a certain moment, after the gas pressure along the pipe has been equalized, the cover of the pipe was removed rapidly leading to a sudden drop (threshold) of the gas pressure at the face of the briquette. An outburst occurred when the threshold of pressure was sufficiently high. A working hypothesis is put forward according to which the destruction of the briquette consists in successive breaking off of very thin layers - flakes. The successive flake is torn off the briquette when the drop of gas pressure in the flake thickness exceeds the tensile strength of the briquette. 12 refs., 5 figs., 3 tabs.

Bodziony, J.; Nelicki, A.; Topolnicki, J. (Polska Akademia Nauk, Krakow (Poland). Instytut Mechaniki Gorotworu)

1989-01-01

152

Laboratory investigation for estimation of seismic response of the ground  

International Nuclear Information System (INIS)

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

2007-01-01

153

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.

2010-06-28

154

Experimental performance investigation of ventilation schemes in a private bathroom  

Energy Technology Data Exchange (ETDEWEB)

This paper presents an experimental modeling of unpleasant odor dispersion from the toilet in a bathroom mockup. A hypothetical odor (SF{sub 6} tracer gas) was emitted from the position of a dummy sitting on the toilet in the bathroom. This experimental investigation aimed to examine the influence of ventilation schemes on the ventilation performance of the unpleasant odor removal. Three ventilation schemes of the bathroom have been investigated in the present study: (1) model A, forced ceiling-supply and wall-exhaust systems, (2) model B, natural window-inlet and forced ceiling-exhaust systems, and (3) model C, forced ceiling-supply and ceiling-exhaust systems. This research employed the tracer gas decay (step-down) method to evaluate the age of air and the air exchange efficiency in the bathroom and the constant injection method to investigate the odor removal efficiency of the bathroom under the three studied ventilation schemes. Results show that the ventilation performance from high to low was model A, C, and B. (author)

Tung, Yun-Chun; Shih, Yang-Cheng; Hu, Shih-Cheng; Chang, Yi-Lang [Department of Energy and Refrigerating Air-Conditioning Engineering, National Taipei University of Technology, 1, Sec. 3, Chung-Hsiao E. Rd., Taipei, 106 (China)

2010-01-15

155

Preliminary experimental investigation of boundary layer in decelerating flow  

Science.gov (United States)

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.

Hladík, O.; Jonáš, P.; P?íhoda, J.

2013-04-01

156

Experimental investigations on nonlinear dynamics in supercontinuum generation with feedback.  

Science.gov (United States)

A system for supercontinuum generation by using a photonic crystal fiber within a synchronously pumped ring cavity is presented. The feedback led to an interaction of the generated supercontinuum with the following femtosecond laser pulses and thus to the formation of a nonlinear oscillator. The nonlinear dynamical behavior of this system was investigated experimentally and compared with numerical simulations. Steady state, period doubling and higher order multiplication of the repetition rate as well as limit cycle and chaotic behavior were observed in the supercontinuum generating system. PMID:20389740

Brauckmann, Nicoletta; Kues, Michael; Walbaum, Till; Gross, Petra; Fallnich, Carsten

2010-03-29

157

Experimental investigations on nonlinear dynamics in supercontinuum generation with feedback.  

UK PubMed Central (United Kingdom)

A system for supercontinuum generation by using a photonic crystal fiber within a synchronously pumped ring cavity is presented. The feedback led to an interaction of the generated supercontinuum with the following femtosecond laser pulses and thus to the formation of a nonlinear oscillator. The nonlinear dynamical behavior of this system was investigated experimentally and compared with numerical simulations. Steady state, period doubling and higher order multiplication of the repetition rate as well as limit cycle and chaotic behavior were observed in the supercontinuum generating system.

Brauckmann N; Kues M; Walbaum T; Gross P; Fallnich C

2010-03-01

158

Experimental investigation of system effects in stressed-skin elements  

DEFF Research Database (Denmark)

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.

Dela Stang, B.; Isaksson, T.

2002-01-01

159

Experimental investigation of neutron emission mechanism for 252 Cf fission  

International Nuclear Information System (INIS)

The mechanism of prompt neutron emission in 252 Cf fission is investigated basing on the comparison of the measured spectra for neutron escape angles of 0 and 90 deg relative to the fission axis. It is revealed that neutron yield for the angle of 90 deg is 5.2 ± 2.1 % greater than the value predicted by the model of isotropy emission calculated on the base of experimental spectra for the angle of 0 deg. It is shown that this deviation amounts to 2.5 ± 1 % if being re-estimated for total neutron yield

1998-01-01

160

Heat transfer crisis on sintered porous surfaces – experimental investigations  

Directory of Open Access Journals (Sweden)

Full Text Available There were presented the results of theoretical analysis of boiling heat transfer on heating surfaces covered with thin-layered capillary porous structures. The paper discussed the results of experimental investigations into intralayer boiling crisis and accompanying phenomena. It was observed that the structural parameters of the porous covering affected the course of the process. Hysteresis phenomenon manifested itself when the heat flux initiating intralayer heat crisis was reached. The crisis mechanism hypotheses, the description of which was available in literature, were discussed.

Wojcik Tadeusz Michal

2012-01-01

 
 
 
 
161

Numerical and experimental investigation into the aerodynamics of dragonfly flight.  

Science.gov (United States)

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

Russell, David; Wang, Z. Jane

2004-11-01

162

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

Directory of Open Access Journals (Sweden)

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.

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

163

Laboratory and Theoretical Investigations of a Ring-Capacitor Sensor  

Science.gov (United States)

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

164

Laboratory investigation of inversion of heavy oil emulsions  

Energy Technology Data Exchange (ETDEWEB)

The feasibility of transporting heavy oil-in-water emulsions via pipelines as an alternative to trucking was examined in a series of laboratory tests. Tests were conducted to examine the effects of several variables such as oil source, droplet size and shear intensity on emulsion durability. The emulsions used in the tests contained 65 per cent oil-in-water and were prepared using polyethoxy nonylphenol surfactants because such emulsions require very low pressure gradients for pipeline transportation as long as inversion does not occur. A bench scale stirred vessel and a rotated pipe toroid were both used to simulate the shear process which occurs in pipeline flow. Liquid chromatography was used to follow the progress of the emulsions toward inversion. At inversion, the surfactant concentration fell below the threshold level needed to sustain on oil-in-water emulsion. It was concluded that the lifetime of the emulsion depends on the initial surfactant dose, the solids content of the crude oil as well as the intensity and nature of the shear process. It was suggested that wellhead crudes may need higher surfactant dosages than treated crudes to avoid the effects of solids. It was also determined that laminar flow is less desirable than turbulent flow. 14 refs., 2 tabs., 10 figs.

Gillies, R.; Sun, R.; Shook, C.A. [Saskatchewan Research Council, Saskatoon, SK (Canada)

2000-08-01

165

Intrinsic bioremediation of gas condensate hydrocarbons - field and laboratory investigations  

Energy Technology Data Exchange (ETDEWEB)

Condensate liquids have been found to contaminate soil and groundwater at two gas production sites in the Denver Basin operated by Amoco Production Co. These sites have been closely monitored since July, 1993, to determine whether intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurs at a sufficient rate and to an adequate endpoint to support a no-intervention decision. Groundwater monitoring and analysis of soil cores suggest that intrinsic bioremediation is occurring at these sites by multiple pathways including aerobic oxidation, Fe(III) reduction and sulfate reduction. In laboratory experiments the addition of gas condensate hydrocarbons to saturated soil from the gas production site stimulated sulfate reduction under anaerobic and oxygen-limiting conditions, and nitrate and Fe(III) reduction under oxygen-limiting conditions, compared to biotic controls that lacked hydrocarbon and sterile controls. The sulfate reduction corresponded to a reduction in the amount of toluene relative to other hydrocarbons. These results confirmed that subsurface soils at the gas production site have the potential for intrinsic bioremediation of hydrocarbons.

Barker, G.W.; Raterman, K.T.; Fisher, J.B.; Corgan, J.M. [and others

1995-12-31

166

Experimental investigation of the permeability for unconsolidated porous media  

Energy Technology Data Exchange (ETDEWEB)

A device was constructed to investigate the permeability of unconsolidated media at low flow rate and small pressure drop. The stability and reliability of the device have been verified through repeated experiments on a given porous medium. The experimental investigation on the porous media demonstrated that the permeability-porosity relation is unique for a given medium. Experiments with the narrow screened sands show that conventional hydrodynamics theory and dimension analysis can not be applied satisfactorily in the study of the capillary porous media. For screened sand whose particle size ranges from 0.10mm to 0.45mm and size rate is 1:1.25, the permeability can be estimated from formula k = 4.89 x 10{sup {minus}4} d{sup 1.465} {phi}{sup 4.69} where k and d are limited in m{sup 2} and m, respectively.

Lei, S.Y.; Jia, L.Q.; Xia, C.M.; Zheng, G.Y.

1997-07-01

167

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.

2007-01-01

168

Computational and Experimental Investigations of Boundary Layer Tripping  

Directory of Open Access Journals (Sweden)

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.

M.R Heidari; M.R Soltani; M. Farahani; M. Taeibi-Rahni

2010-01-01

169

Experimental and numerical investigations of shape memory alloy helical springs  

Science.gov (United States)

Shape memory alloys (SMAs) belong to the class of smart materials and have been used in numerous applications. Solid phase transformations induced either by stress or temperature are behind the remarkable properties of SMAs that motivate the concept of innovative smart actuators for different purposes. The SMA element used in these actuators can assume different forms and a spring is an element usually employed for this aim. This contribution deals with the modeling, simulation and experimental analysis of SMA helical springs. Basically, a one-dimensional constitutive model is assumed to describe the SMA thermomechanical shear behavior and, afterwards, helical springs are modeled by considering a classical approach for linear-elastic springs. A numerical method based on the operator split technique is developed. SMA helical spring thermomechanical behavior is investigated through experimental tests performed with different thermomechanical loadings. Shape memory and pseudoelastic effects are treated. Numerical simulations show that the model results are in close agreement with those obtained by experimental tests, revealing that the proposed model captures the general thermomechanical behavior of SMA springs.

Aguiar, Ricardo A. A.; Savi, Marcelo A.; Pacheco, Pedro M. C. L.

2010-02-01

170

Experimental investigations of the development of the marine aerosol population  

Energy Technology Data Exchange (ETDEWEB)

This report describes a series of experiments designed to study the air mass directly above the ocean in an effort to better understand the development of the atmospheric aerosols which comprise marine haze. To determine the nature of the boundary layer haze, one must first characterize the composition and size distribution of the particles that comprise the haze, identify the source(s) of those particles and specify the source strength and growth rate of the resulting aerosol. Ultimately, of course, development of a model of the complete system is desired so that better forecasts of haze over the ocean can be made. The first set of sea measurements had two objectives: (1) to investigate the effects of environmental parameters on the emission rate of DMS from the ocean into the atmosphere, and (2) to track in the atmospheric marine boundary layer the DMS photochemistry that has been observed in laboratory photolysis studies.

Wattle, B.J.; Rogers, C.W.; Flanigan, M.C.; Pilie, R.J.

1992-10-01

171

An Experimental Investigation of the Scaling of Columnar Joints  

CERN Document Server

Columnar jointing is a fracture pattern common in igneous rocks in which cracks self-organize into a roughly hexagonal arrangement, leaving behind an ordered colonnade. We report observations of columnar jointing in a laboratory analog system, desiccated corn starch slurries. Using measurements of moisture density, evaporation rates, and fracture advance rates as evidence, we suggest an advective-diffusive system is responsible for the rough scaling behavior of columnar joints. This theory explains the order of magnitude difference in scales between jointing in lavas and in starches. We investigated the scaling of average columnar cross-sectional areas due to the evaporation rate, the analog of the cooling rate of igneous columnar joints. We measured column areas in experiments where the evaporation rate depended on lamp height and time, in experiments where the evaporation rate was fixed using feedback methods, and in experiments where gelatin was added to vary the rheology of the starch. Our results suggest...

Goehring, L; Morris, S; Goehring, Lucas; Lin, Zhenqun; Morris, Stephen

2006-01-01

172

Experimental investigation of effects of external loads on erosive wear  

Directory of Open Access Journals (Sweden)

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.

H. Imrek; M. Bagci; O.M. Khalfan

2009-01-01

173

Experimentally investigate ionospheric depletion chemicals in artificially created ionosphere  

Energy Technology Data Exchange (ETDEWEB)

A new approach for investigating ionosphere chemical depletion in the laboratory is introduced. Air glow discharge plasma closely resembling the ionosphere in both composition and chemical reactions is used as the artificially created ionosphere. The ionospheric depletion experiment is accomplished by releasing chemicals such as SF{sub 6}, CCl{sub 2}F{sub 2}, and CO{sub 2} into the model discharge. The evolution of the electron density is investigated by varying the plasma pressure and input power. It is found that the negative ion (SF{sub 6}{sup -}, CCl{sub 2}F{sub 2}{sup -}) intermediary species provide larger reduction of the electron density than the positive ion (CO{sub 2}{sup +}) intermediary species. The negative ion intermediary species are also more efficient in producing ionospheric holes because of their fast reaction rates. Airglow enhancement attributed to SF{sub 6} and CO{sub 2} releases agrees well with the published data. Compared to the traditional methods, the new scheme is simpler to use, both in the release of chemicals and in the electron density measurements. It is therefore more efficient for investigating the release of chemicals in the ionosphere.

Liu Yu; Cao Jinxiang; Wang Jian; Zheng Zhe; Xu Liang; Du Yinchang [CAS Key Laboratory of Basic Plasma Physics, Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2012-09-15

174

Experimental investigation of buried tritium in plant and animal tissues  

International Nuclear Information System (INIS)

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

2008-01-01

175

Experimental Investigations of Hydrogen Purification by Purging through Metal Hydride  

Directory of Open Access Journals (Sweden)

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.

Blinov D.V.; Malyshenko S.P.; Borzenko V.I.; Dunikov D.O.

2012-01-01

176

Combined analytical and experimental investigations for LWR containment phenomena  

International Nuclear Information System (INIS)

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

2012-01-01

177

Combined analytical and experimental investigations for LWR containment phenomena  

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-04-15

178

Laboratory investigations on granulation ability of brown coal dust  

Energy Technology Data Exchange (ETDEWEB)

This article presents detailed results of laboratory granulation experiments employing pulverized soft brown coal, carried out with the aim of reducing the strong flow behavior of coal dust. The granulated coal dust (produced by compacting dust on a roller press to sheets of 4 mm thickness and crumbling of the sheet) was briquetted on a briquetting press and then coked in a brown coal high temperature coking furnace. Three variants of granulation were tried; granulation results and the influence of the granulation method on quality of produced coking briquets and coke, in particular compression strength, are evaluated. The first variant was granulating dry brown coal dust with the addition of up to 25% comminuted brown coal in a grain size of 1/0 mm and with 11% moisture content. This measure substantially reduced the flow behavior of the dust but also lowered the compression strength of the resulting coke to some degree (in one test from 35.2 to 34.6 MPa and in another from 40.7 to 32.8 MPa). The second variant was granulating dust with a higher moisture content (25 to 30%) at a pressure of 15 MPa, followed by drying of the granules to 8-11% moisture content. This method largely eliminated coal dust flow and did not reduce coke strength: coke with strength up to 44.4 MPa was produced. The third method consisted of granulating the dust in a steam atmosphere with a coal/steam relation of 150:1. This method only lowered the dust flow to some extent; the compression strength of the resulting coke was lowered after longer steaming intervals. Conclusive results of the methods will require testing on an industrial scale. (10 refs.)

Krug H.; Naundorf, W.; Trommer, D.

1982-01-01

179

Laboratory investigations of the survivability of bacteria in hypervelocity impacts.  

UK PubMed Central (United Kingdom)

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

Burchell MJ; Shrine NR; Mann J; Bunch AW; Brandao P; Zarnecki JC; Galloway JA

2001-01-01

180

Laboratory investigations of the survivability of bacteria in hypervelocity impacts.  

Science.gov (United States)

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

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

2001-01-01

 
 
 
 
181

Quality assurance plan for the Close Support Laboratory for the remedial investigation at Oak Ridge National Laboratory, Oak Ridge, Tennessee  

International Nuclear Information System (INIS)

The primary purpose of the Close Support Laboratory (CSL) is to provide rapid radiological screening of investigation-derived samples before they are shipped to off-site laboratories for more detailed analyses. Analyses for volatile organic compounds and miscellaneous water quality parameters are also performed at the CSL. CSL data are also used to select samples for off-site laboratory analysis, for rapid qualitative and quantitative determinations, and for other processes when off-site analysis is not needed and/or is impractical. This plan specifies methods of implementing analytical and radiological protocols and procedures for the documentation, handling, control, and analysis of samples and describes the levels of authority and responsibility for laboratory operation. Specific quality control methods used by the CSL for individual analyses are described in project procedures.

1993-01-01

182

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

Science.gov (United States)

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

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

2007-01-01

183

Methods of experimental physics. Volume 24: Geophysics, Part A; laboratory measurements  

Energy Technology Data Exchange (ETDEWEB)

Geophysics use many of the methods and techniques of physics to study the solid earth and planets. Experimental techniques in modern geophysics naturally fall into two categories: field and laboratory. Field experiments are designed to collect basic data on the structure of earth and planetary interiors, the dynamic processes by which these bodies evolve, and the nature and source of any planetary field. Laboratory experiments are designed to aid the interpretation of the basic field data, and to make inferences when no primary data are available. Part A discusses the laboratory techniques.

Celotta, R.; Levine, J.; Sammis, C.G.; Henyey, T.L.

1987-01-01

184

33 CFR 334.150 - Severn River at Annapolis, Md.; experimental test area, U.S. Navy Marine Engineering Laboratory.  

Science.gov (United States)

...experimental test area, U.S. Navy Marine Engineering Laboratory. 334.150 Section 334...experimental test area, U.S. Navy Marine Engineering Laboratory. (a) The restricted...southeasternmost corner of the U.S. Navy Marine Engineering Laboratory sea wall and...

2013-07-01

185

Experimental investigation of the acceleration of deflagration in wake flow  

International Nuclear Information System (INIS)

[en] 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)

1985-01-01

186

Subsurface investigation of the Energy Systems Research Laboratory site at Oak Ridge National Laboratory  

International Nuclear Information System (INIS)

Subsurface soil from the site of the proposed Energy Systems Research Laboratory was examined to determine radioactive concentration levels. This study was undertaken because the proposed site is in close proximity to the former Solid Waste Storage Area-2. A total of 25 cores were taken, ranging in depth from 4 to 9 feet, and the soil samples were analyzed for gamma-, beta-, and alpha-emitting isotopes. Water taken from 13 of the core holes was analyzed to determine tritium, gross beta, and gross alpha levels. None of the samples analyzed were found to be significantly higher than background samples collected throughout eastern and central Tennessee. No special health physics precautions are expected to be needed for the excavation at the site, other than using the excavated soil as backfill at burial sites on the reservation

1977-01-01

187

Experimental investigations of silicon tetrafluoride decomposition in ECR discharge plasma.  

UK PubMed Central (United Kingdom)

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

Vodopyanov AV; Golubev SV; Mansfeld DA; Sennikov PG; Drozdov YN

2011-06-01

188

EXPERIMENTAL INVESTIGATION ON HIGH PERFORMANCE CONCRETE USING SILICAFUME AND FLYASH  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this experimental investigation is to study the behaviour of High Performance Concrete (HPC). In this investigation HPC was manufactured by usual ingredients such as cement, fine aggregate, coarse aggregate, water and mineral admixtures such as Silica Fume (SF) and Fly ash at various replacement levels and with Super Plasticizer. The water binder ratio (w/b) adopted is 0.30. The concrete used in this investigation was proportioned to target a mean strength of 60 MPa. Specimens such as cubes, cylinders and prism beams were cast and tested for various mixes viz. Seven mixes M1 to M7 are cast with 0%, 5%, 7.5% and 10% replacement of SF and another set of specimens with 0%, 5%, 7.5% and 10% replacement of SF along with 10% constant replacement of Fly ash to study the mechanical properties such as compressive strength, split tensile strength and flexural strength at different ages of concrete such as 3, 7, 28, 56 and 90 days. The result shows that the optimum replacement of silica fume is 7.5%. Totally The specimens were tested in 1000 kN loading frame at 28 days. The results were tabulated.

Kannan Kannan

2012-01-01

189

HCN{sup 2+} dication spectroscopy: theoretical and experimental investigations  

Energy Technology Data Exchange (ETDEWEB)

The present work combines experimental and theoretical investigations of HCN{sup 2+} to investigate the spectroscopy and dissociation dynamics of this dication. Its spectrum is a complex blend of overlapping features, consistent with theoretical calculations showing that the low-lying electronic states of HCN{sup 2+} exhibit Renner-Teller and vibronic interactions. The double ionisation spectra are dominated by C-N stretching excitations for all the electronic states investigated. Long-lived HCN{sup 2+} ions are observed and are believed to be in low vibrational levels of the X {sup 3}{sigma}{sup -} and/or {sup 1}{delta} and/or {sup 1}{sigma}{sup +} electronic states; some have metastable lifetimes of about 25 ns. The formation of H{sup +} + CN{sup +} products is attributed to predissociation by the lowest {sup 3}A' component resulting from a conical intersection between the X {sup 3}{sigma}{sup -} and {sup 3}{pi} states. The overall predissociation processes involve vibronic, Renner-Teller and spin-orbit couplings between several electronic states of HCN{sup 2+}.

Hochlaf, M. [Theoretical Chemistry Group, University of Marne-la-Vallee, Champs sur Marne, F-77454 Marne-la-Vallee Cedex 2 (France)]. E-mail: hochlaf@univ-mlv.fr; Pilcher-Clayton, A. [Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ (United Kingdom); Eland, J.H.D. [Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ (United Kingdom)]. E-mail: eland@physchem.ox.ac.uk

2005-03-14

190

Experimental investigations in turbulent buoyant jets of sodium  

International Nuclear Information System (INIS)

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

1993-01-01

191

Experimental investigations on vessel-hole ablation during severe accidents  

Energy Technology Data Exchange (ETDEWEB)

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-B{sub 2}O{sub 3} or the binary eutectic and non-eutectic salts NaNO{sub 3}-KNO{sub 3}, 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. 40 refs, 51 figs, 13 tabs.

Sehgal, B.R.; Dinh, T.N.; Green, J.A.; Paladino, D. [Royal Inst. of Tech., Stockholm (Sweden). Div. of Nuclear Power Safety

1997-12-01

192

An Investigation of Laboratory-Grown "Ice Spikes"  

CERN Multimedia

We have investigated the formation of 10-50 mm long ``ice spikes'' that sometimes appear on the free surface of water when it solidifies. By freezing water under different conditions, we measured the probability of ice spike formation as a function of: 1) the air temperature in the freezing chamber, 2) air motion in the freezing chamber (which promotes evaporative cooling), 3) the quantity of dissolved salts in the water, and 4) the size, shape, and composing material of the freezing vessel. We found that the probability of ice spike formation is greatest when the air temperature is near -7 C, the water is pure, and the air in the freezing chamber is moving. Even small quantities of dissolved solids greatly reduce the probability of ice spike formation. Under optimal conditions, approximately half the ice cubes in an ordinary ice cube tray will form ice spikes. Guided by these observations, we have examined the Bally-Dorsey model for the formation of ice spikes. In this model, the density change during solidi...

Libbrecht, K G

2003-01-01

193

Site Safety Plan for Lawrence Livermore National Laboratory CERCLA investigations  

Energy Technology Data Exchange (ETDEWEB)

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.

Bainer, R.; Duarte, J.

1993-07-01

194

Experimental Investigation of Turbulent Flow in Transition Duct  

Directory of Open Access Journals (Sweden)

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.

Hasan GÜL

2012-01-01

195

Transport of bacteria in porous media; 1: An experimental investigation  

Energy Technology Data Exchange (ETDEWEB)

The convective transport of concentrated suspensions of bacteria in porous media is of interest for several processes such as microbial enhanced oil recovery and in situ bioremediation. The parameters which affect the transport of the bacterium Bacillus licheniformis JF-2, a candidate microorganism for microbial enhanced oil recovery, were investigated experimentally in sandpacks. Bacteria retention and permeability reduction occurred primarily in the first few centimeters upon entering the porous medium. In downstream sections of the sandpack, the permeability reduction was low, even in cases in which high cell concentrations were detected in the effluent. The effects of (1) addition of a dispersant, (2) linear velocity of injection, (3) cell concentration, (4) salinity, (5) temperature, and (6) the presence of a residual oleic phase were determined experimentally. A lower reduction in permeability and a higher effluent bacterial concentration were obtained in the presence of dispersant, high injection velocities, low salinities, and at a higher temperature. Macroscopic measurements at different linear velocities and in the presence or absence of dispersants suggest that the formation of reversible microaggregates and multiparticle hydrodynamic exclusion may be the primary mechanisms for bacterial retention and permeability reduction.

Sarkar, A.K.; Georgiou, G.; Sharma, M.M. (Univ. of Texas, Austin, TX (United States))

1994-08-05

196

Experimental investigations on dynamic effects in impact notch bending tests  

International Nuclear Information System (INIS)

[en] 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)[de] Das dynamische Verhalten von Dreipunktbiegeproben unter Schlagbeanspruchung wird experimentell untersucht. Dazu werden verschiedene Messverfahren, vor allem das schattenoptische Kaustikenverfahren eingesetzt. Zur quantitativen Beschreibung des Beanspruchungsverhaltens wird mit einem einfachen Feder-Masse-Modell eine quasistatische Analyse durchgefuehrt. Basierend darauf werden die dynamischen Effekte in Modellexperimenten quantitativ mit dynamischen Korrekturfunktionen erfasst und in Bezug auf Wellenvorgaenge in der Probe diskutiert. Dabei ergibt sich auch eine systematische Uebersicht ueber den Einfluss der zahlreichen Systemparameter auf das dynamische Beanspruchungsverhalten. Abschliessend wird an Beispielen aufgezeigt, dass die Ergebnisse dieser Modelluntersuchungen auf andere Versuchsbedingungen uebertragbar sind. (orig./HP)

1985-01-01

197

Experimental Investigation on the Viscosity of Nano fluids  

International Nuclear Information System (INIS)

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

2012-01-01

198

Experimental investigation of a two-phase nozzle flow  

International Nuclear Information System (INIS)

[en] 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.)

1980-01-01

199

Experimental investigations of the functional morphology of dragonfly wings  

Science.gov (United States)

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

Rajabi, H.; Darvizeh, A.

2013-08-01

200

Experimental in situ investigations of turbulence under high pressure.  

UK PubMed Central (United Kingdom)

In tube injection systems applied in high-pressure processing of packed biomaterials and foods, the pressure-transmitting medium is injected into the vessel to increase the pressure up to 1000 MPa, generating a submerged liquid-free jet. The presence of a turbulent-free jet during the pressurization phase and its positive influence on the homogeneity of the product treatment has already been examined by computational fluid dynamics investigations. However, no experimental data have supported the existence and properties of turbulent flow under high-pressure (HP) conditions up to 400 MPa. This contribution presents the development of two experimental setups: HP-laser Doppler anemometry and HP-hot wire anemometry. For the first time the time-averaged velocity profiles of a free jet during pressurization up to 300 MPa at different Reynolds numbers (Re) have been obtained. In this article, the dependence of the velocity profiles on the Re is discussed in detail. Moreover, the relaminarization phenomenon of the turbulent pipe flow most likely caused by the compressibility effects and viscosity changes of the pressure-transmitting medium is examined.

Song K; Al-Salaymeh A; Jovanovic J; Rauh C; Delgado A

2010-02-01

 
 
 
 
201

Experimental in situ investigations of turbulence under high pressure.  

Science.gov (United States)

In tube injection systems applied in high-pressure processing of packed biomaterials and foods, the pressure-transmitting medium is injected into the vessel to increase the pressure up to 1000 MPa, generating a submerged liquid-free jet. The presence of a turbulent-free jet during the pressurization phase and its positive influence on the homogeneity of the product treatment has already been examined by computational fluid dynamics investigations. However, no experimental data have supported the existence and properties of turbulent flow under high-pressure (HP) conditions up to 400 MPa. This contribution presents the development of two experimental setups: HP-laser Doppler anemometry and HP-hot wire anemometry. For the first time the time-averaged velocity profiles of a free jet during pressurization up to 300 MPa at different Reynolds numbers (Re) have been obtained. In this article, the dependence of the velocity profiles on the Re is discussed in detail. Moreover, the relaminarization phenomenon of the turbulent pipe flow most likely caused by the compressibility effects and viscosity changes of the pressure-transmitting medium is examined. PMID:20233365

Song, Kwonyul; Al-Salaymeh, Ahmed; Jovanovic, Jovan; Rauh, Cornelia; Delgado, Antonio

2010-02-01

202

Experimental Investigation of Turbulence Specifications of Turbidity Currents  

Directory of Open Access Journals (Sweden)

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.

B Firoozabadi; H. Afshin; A. Bagherpour

2010-01-01

203

Experimental investigation on a thermoelectric refrigerator driven by solar cells  

Energy Technology Data Exchange (ETDEWEB)

Experimental investigation and relevant analysis on a solar cell driven, thermoelectric refrigerator has been conducted. To make the device portable, daytime use and nighttime use of the refrigerator are treated in different ways. Solar cells are applied to power the refrigerator in the day. Storage battery, assisted by an a.c. rectifier, is used to provide electric energy in the night and in cloudy or rainy days. Experiment results demonstrate that the unit can maintain the temperature in the refrigerator at 5-10{sup o}C, and have a COP about 0.3. It is expected that the refrigerator would be potential for cold storage of vaccine, foodstuffs and drink in remote areas, or outdoor applications where electric power supply is absent. (Author)

Dai, Y.J.; Wang, R.Z.; Ni, L. [Shanghai Jiao Tong Univ. (China). Inst. of Refrigeration and Cryogenics

2003-05-01

204

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

DEFF Research Database (Denmark)

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.

Berring, Peter; Branner, Kim

2007-01-01

205

Experimental investigation of turbulent flows in pipe junctions  

International Nuclear Information System (INIS)

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

1989-01-01

206

Torque scaling in Taylor-Couette flow — an experimental investigation  

International Nuclear Information System (INIS)

Within this work we investigate experimentally the turbulent flow between two independently rotating concentric cylinders with radius ratio ? = 0.5. The angular velocity of the fluid ? across the gap is measured by Particle Image Velocimetry and Laser Doppler Anemometry for different rotation rates of the inner and outer cylinder. The aim is to analyse the angular momentum transport J?. In relation to this we measure, in addition to the optical methods, the torque effecting at the inner cylinder. For the case that only the outer cylinder rotates and the inner cylinder is at rest, we show, that for this linear stable flow, the torque is comparatively high and its dependency a non-trivial problem.

2011-12-22

207

Experimental Investigation of the Induced Airflow of Corona Discharge  

Science.gov (United States)

In order to improve the acceleration effect of corona discharge acting on air, we present an experimental study on the induced airflow produced by corona discharge between two parallel electrodes. The parameters investigated are the type of electrodes, actuation voltage and the distance in the absence of free airflow. The induced flow velocity is measured directly in the accelerated region using the particle image velocimetry technology. The results show that if corona discharge is not developed into arc discharge, the induced airflow velocity increases nearly linearly with the applied voltage and the maximum induced airflow velocity near the needle electrode reaches 36 m/s. It is expected that in the future, the result can be referred to in the research about effect of active flow control to reach much higher induced airflow speed.

Huang, Yong; Zhang, Xin; Wang, Xun-Nian; Wang, Wan-Bo; Huang, Zong-Bo; Li, Hua-Xing

2013-09-01

208

Coronary Artery Stenosis Flow: Experimental and Computational Investigation  

Science.gov (United States)

The effects of symmetry, flowrate, wall roughness and size are investigated using realistic pulsatile waveforms for flow viz and LDV experimental models as well as CFD models using original code. Distal to the stenosis flow is characterized by a high speed jet which is central for symmetric models and attached to the wall for eccentric models. The jet is accompanied by a low speed recirculation zone which persists while lengthening and shortening during most of the cardiac cycle. Of particular note is the downstream onset of flow instability and turbulence for high flow rate conditions in symmetric and eccentric severely occluded stenoses. The location and extent of the unstable flow region continually changes throughout the cycle, which may be a factor contributing to the thrombogenesis which coronary arteries experience.

Egelhoff, Carla; Budwig, Ralph; Hansen, Byron; Foster, Jonathan

2000-11-01

209

Experimental investigation of plastic deformations before a granular avalanche.  

UK PubMed Central (United Kingdom)

We present an experimental study of the deformation inside a granular material that is progressively tilted. We investigate the deformation before the avalanche with a spatially resolved diffusive wave spectroscopy setup. At the beginning of the inclination process, we first observe localized and isolated events in the bulk, with a density which decreases with the depth. As the angle of inclination increases, series of microfailures occur periodically in the bulk, and finally a granular avalanche takes place. The microfailures are observed only when the tilt angles are larger than a threshold angle much smaller than the granular avalanche angle. We have characterized the density of reorganizations and the localization of microfailures. We have also explored the effect of the nature of the grains, the relative humidity conditions, and the packing fraction of the sample. We discuss those observations in the framework of the plasticity of granular matter. Microfailures may then be viewed as the result of the accumulation of numerous plastic events.

Amon A; Bertoni R; Crassous J

2013-01-01

210

An experimental-differential investigation of cognitive complexity  

Directory of Open Access Journals (Sweden)

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.

DAMIAN P. BIRNEY; DAVID B. BOWMAN

2009-01-01

211

Experimental investigation on R134a vapour ejector refrigeration system  

Energy Technology Data Exchange (ETDEWEB)

The experimental investigation of the performance of a vapour ejector refrigeration system is described. The system uses R134a as working fluid and has a rated cooling capacity of 0.5kW. The influence of generator, evaporator and condenser temperatures on the system performance is studied. This kind of system can be operated with low grade thermal energy such as solar energy, waste heat, etc. The operating conditions are chosen accordingly as, generator temperature between 338K and 363K, condenser temperature between 299K and 310.5K, and evaporator temperature between 275K and 285.5K. Six configurations of ejectors of different geometrical dimensions are selected for the parametric study. The performance of the refrigeration system at different operating temperatures is presented. (author)

Selvaraju, A.; Mani, A. [Refrigeration and Airconditioning Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, Chennai 600 036 (India)

2006-11-15

212

Experimental and numerical investigation of aerodynamic effects induced by a glow discharge over a cylinder in rarefied supersonic regime  

Science.gov (United States)

This work focuses on the study of plasma effects having an influence on the aerodynamic properties of a rarefied Mach 2 air flow interacting with a cylinder. The effect of a DC glow discharge plasma on the shock wave resulting from the interaction of a Mach 2 supersonic rarefied flow and a cylinder is being studied experimentally and numerically. The flow field is experimentally analysed with a iCCD camera and the experimental images are compared to the calculated Mach number fields. Rotational temperatures deduced from emission spectrometry help to improve physical interpretation by refining input data in the simulation code. The experimental investigation was carried out in the supersonic wind tunnel Marhy located at the Icare laboratory and a numerical investigation using a fully 2D compressible Navier Stokes simulation was carried out at the IUSTI laboratory.

Lago, Viviana; Parisse, Jean Denis; Pons, Jerome; Tinon, Emmanuelle; Kudryavtsev, Alexey N.

2012-11-01

213

Clinical and laboratory investigation of allergy to genetically modified foods.  

Science.gov (United States)

Technology has improved the food supply since the first cultivation of crops. Genetic engineering facilitates the transfer of genes among organisms. Generally, only minute amounts of a specific protein need to be expressed to obtain the desired trait. Food allergy affects only individuals with an abnormal immunologic response to food--6% of children and 1.5-2% of adults in the United States. Not all diseases caused by food allergy are mediated by IgE. A number of expert committees have advised the U.S. government and international organizations on risk assessment for allergenicity of food proteins. These committees have created decision trees largely based on assessment of IgE-mediated food allergenicity. Difficulties include the limited availability of allergen-specific IgE antisera from allergic persons as validated source material, the utility of specific IgE assays, limited characterization of food proteins, cross-reactivity between food and other allergens, and modifications of food proteins by processing. StarLink was a corn variety modified to produce a (Italic)Bacillus thuringiensis(/Italic) (Bt) endotoxin, Cry9C. The Centers for Disease Control and Prevention investigated 51 reports of possible adverse reactions to corn that occurred after the announcement that StarLink, allowed for animal feed, was found in the human food supply. Allergic reactions were not confirmed, but tools for postmarket assessment were limited. Workers in agricultural and food preparation facilities have potential inhalation exposure to plant dusts and flours. In 1999, researchers found that migrant health workers can become sensitized to certain Bt spore extracts after exposure to Bt spraying. PMID:12826483

Bernstein, Jonathan A; Bernstein, I Leonard; Bucchini, Luca; Goldman, Lynn R; Hamilton, Robert G; Lehrer, Samuel; Rubin, Carol; Sampson, Hugh A

2003-06-01

214

Sesame seed allergy: Clinical manifestations and laboratory investigations  

Directory of Open Access Journals (Sweden)

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.

Fazlollahi MR.; Pourpak Z.; Yeganeh M.; Kardor GH.; Kazemnejad A.; Movahedi M.; Gharagozlou M.; Farid Hosseini R.; Farhoudi A.

2007-01-01

215

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1991-12-01

216

Laboratory investigation of the radiative energy transfer during rupture nucleation  

Science.gov (United States)

Triaxial compression experiments were performed on several materials (Glass, Granite, Basalt, Sandstone, Marble and Gypsum) at confining pressures ranging from 10 to 100MPa, and from room temperature to 70 degrees C. During each of these experiments, acoustic waves radiated from damage accumulation and fast crack propagation were continuously monitored thanks to a fast acoustic recorder, which enables to obtain continuous acoustogram of rupture nucleation and propagation, without the limitations of former trigger systems. In our experiments, rupture does not need to be slowed down, and the transition from quasi-static nucleation to dynamic propagation has now been systematically investigated.Comparing each material, three main observation can be drawn : - First, the amount of damage accumulation before the dynamic rupture propagation varies from material to material, and also depends on the pressure and temperature conditions. For instance, glass, granites and sandstones are typically materials where the nucleation involves a large amount of cracking prior to rupture. In contrast, rupture in basalt at low confinement is not preceded by any damage accumulation. Finally, pre-rupture damage accumulation can also be purely aseismic, which is the case of marble for instance. - Second, the brittle-ductile transition does not exactly overlaps the aseismic-seismic transition, at least in the conditions at which we performed our experiments. For example, marble deforms plastically beyond 50MPa, and although the deformation is ductile, a large amount of crack accumulates in the rock, which tends to make it unstable. In the same way, acoustic emissions decrease in gypsum with increasing pressure and temperatures. - Finally, the time during which rupture propagates depends largely on the rheology. For instance, and in the case of ductile failures such as in marble, dislocation and twin accumulation is such that cracks propagation steps are small and/or slow, and thus the radiated energy release rate remains small at early stages of rupture and increases with rupture speed. Put together, our observations clearly highlight the dependence of the radiated acoustic (and microseismic?) energy during rupture nucleation and early stages of crack propagation not only on the rupture propagation speed and the slip velocity but most importantly on the rock’s lithology and rheology.

Schubnel, A. J.; Brantut, N.; Ougier-Simonin, A.; Adelinet, M.; Fortin, J.; Gueguen, Y.

2009-12-01

217

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)

2007-01-01

218

An Experimental Investigation on Inclined Negatively Buoyant Jets  

Directory of Open Access Journals (Sweden)

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.

Raed Bashitialshaaer; Magnus Larson; Kenneth M. Persson

2012-01-01

219

Experimental investigation of water sprayed finned heat exchanger tube bundles  

International Nuclear Information System (INIS)

[en] 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

1987-01-01

220

Ozone decomposition on Saharan dust: an experimental investigation  

Directory of Open Access Journals (Sweden)

Full Text Available The heterogeneous reaction between O3 and authentic Saharan dust surfaces was investigated in a Knudsen reactor at approx 296 K. O3 was destroyed on the dust surface and O2 was formed with conversion efficiencies of 1.0 and 1.3 molecules O2 per O3 molecule destroyed for unheated and heated samples, respectively. No O3 desorbed from exposed dust samples, showing that the uptake was irreversible. The uptake coefficients for the irreversible destruction of O3 on (unheated) Saharan dust surfaces depended on the O3 concentration and varied between 3.5 x10-4 and 5.5 x10-6 for the initial uptake coefficient (g0 approx 3 x10-5 at 30 ppbv O3 STP) and between 4.8 x10-5 and 2.2 x10-6 for the steady-state uptake coefficient (gss approx 7 x10-6 at 30 ppbv O3 STP). At very high O3 concentrations the surface was deactivated, and O3 uptake ceased after a certain exposure period. Sample re-activation (i.e. de-passivation) was found to occur over periods of hours, after exposure to O3 had ceased, suggesting that re-activation processes play a role both in the laboratory and in the atmosphere.

F. Hanisch; J. N. Crowley

2002-01-01

 
 
 
 
221

Ozone decomposition on Saharan dust: an experimental investigation  

Directory of Open Access Journals (Sweden)

Full Text Available The heterogeneous reaction between O3 and authentic Saharan dust surfaces was investigated in a Knudsen reactor at approx 296 K. O3 was destroyed on the dust surface and O2 was formed with conversion efficiencies of 1.0 and 1.3 molecules O2 per O3 molecule destroyed for unheated and heated samples, respectively. No O3 desorbed from exposed dust samples, showing that the uptake was irreversible. The uptake coefficients for the irreversible destruction of O3 on (unheated) Saharan dust surfaces depended on the O3 concentration and varied between 3.5 x 10-4 and 5.5 x 10-6 for the initial uptake coefficient (g0 approx 3 x 10-5 at 30 ppbv O3 STP) and between 4.8 x 10-5 and 2.2 x 10-6 for the steady-state uptake coefficient (gss approx 7 x10-6 at 30 ppbv O3 STP). At very high O3 concentrations the surface was deactivated, and O3 uptake ceased after a certain exposure period. Sample re-activation (i.e. de-passivation) was found to occur over periods of hours, after exposure to O3 had ceased, suggesting that re-activation processes play a role both in the laboratory and in the atmosphere.

F. Hanisch; J. N. Crowley

2003-01-01

222

Experimental investigation of filtered epithermal-photoneutron Beams for BNCT  

Energy Technology Data Exchange (ETDEWEB)

The Idaho National Engineering Laboratory (INEL) has been investigating the feasibility of a concept for an accelerator-based source of epithermal neutrons for BNCT that is based on the use of a two-stage photoneutron production process driven by an electron accelerator. In this concept, relativistic electron beams impinge upon heavily-shielded tungsten targets located at the outer radius of a small cylindrical tank of circulating heavy water (D{sub 2}0). A fraction of the energy of the electrons is converted in the tungsten targets into radially-inward-directed bremsstrahlung radiation. Neutrons subsequently generated by photodisintegration of deuterons in the D{sub 2}O within the tank are directed to the patient through a suitable beam tailoring system. Initial proof-of-principal tests using a low-current benchtop prototype of this concept have been conducted. Testing has included extensive measurements of the unfiltered photoneutron source as well as initial measurements of filtered epithermal-neutron spectra produced using two different advanced neutron filtering assemblies, as described here.

Nigg, D.W.; Mitchell, H.E.; Harker, Y.D. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Harmon, J.F. [Idaho State Univ., Pocatello, ID (United States)

1996-12-31

223

Experimental investigation of the acceleration of deflagration in wake flow  

International Nuclear Information System (INIS)

[en] 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

1983-01-01

224

Experimental investigation of the scaling of columnar joints.  

UK PubMed Central (United Kingdom)

Columnar jointing is a fracture pattern common in igneous rocks in which cracks self-organize into a roughly hexagonal arrangement, leaving behind an ordered colonnade. We report observations of columnar jointing in a laboratory analog system, desiccated corn starch slurries. Using measurements of moisture density, evaporation rates, and fracture advance rates as evidence, we suggest that an advective-diffusive system is responsible for the rough scaling behavior of columnar joints. This theory explains the order of magnitude difference in scales between jointing in lavas and in starches. We investigated the scaling of average columnar cross-sectional areas due to the evaporation rate, the analog of the cooling rate of igneous columnar joints. We measured column areas in experiments where the evaporation rate depended on lamp height and time, in experiments where the evaporation rate was fixed using feedback methods, and in experiments where gelatin was added to vary the rheology of the starch. Our results suggest that the column area at a particular depth is related to both the current conditions, and hysteretically to the geometry of the pattern at previous depths. We argue that there exists a range of stable column scales allowed for any particular evaporation rate.

Goehring L; Morris SW; Lin Z

2006-09-01

225

Experimental investigation of kinetics and rheology during diagenesis  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1998-09-01

226

Combined Experimental and Numerical Investigations into Laser Propulsion Engineering Physics  

Science.gov (United States)

The RPI pulsed Laser Propulsion (LP) research effort focuses on the future application of launching nano- and micro-satellites (1-10 kg payloads) into Low Earth Orbit (LEO), using a remote Ground Based Laser (GBL) power station to supply the required energy for flight. This research program includes both experimental and numerical studies investigating the propulsive performance of several engine geometries (constituting a lightcraft family). Using the Lumonics twin K-922m TEA pulsed laser system, axial and lateral thrust, C m, Isp, and ? measurements were made for these engine geometries, examining the effects of several critical factors including: engine orientation (e.g. lateral and angular offset), laser pulse energy, pulse repetition frequency, pulse duration, propellant type, and engine size-scaling effects. Investigation into the origins of lateral "beam riding" forces was of particular interest. Lateral impulse measurements and high speed Schlieren photography were utilized to provide an understanding of laser beam-riding/propulsive physics. The acquired lightcraft database was used to further develop an existing 7-Degree Of Freedom (DOF) flight dynamics model extensively calibrated against 16 actual trajectories of small scale model lightcraft flown at White Sands Missile Range, NM on a 10 kW pulsed CO2 laser called PLVTS. The full system 7-DOF model is comprised of updated individual aerodynamics, engine, laser beam propagation, variable vehicle inertia, reaction controls system, and dynamics models, integrated to represent all major phenomena in a consistent framework. This flight dynamics model and associated 7-DOF code provide a physics-based predictive tool for basic research investigations into laser launched lightcraft for suborbital and orbital missions. Simulations were performed to demonstrate the flight capabilities of each engine geometry using the updated lightcraft propulsion database, the results of which further demonstrate that autonomous beam riding capability is an essential component for a stable launch to orbit and the future of LP.

Kenoyer, David Adam

227

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).

1994-01-01

228

Combustion Behaviour of Pulverised Wood - Numerical and Experimental Studies. Experimental Studies of two Pulverised Wood Flames in TPS Laboratory Vertical Furnace  

Energy Technology Data Exchange (ETDEWEB)

This work is part of a collaboration project between TPS and LTH for combined numerical modelling/experimental investigation on combustion of pulverised wood. This report presents the experimental work that has been carried out in the TPS laboratory vertical furnace during the second phase of the project (2002-07-01 - 2003-07-01). The experimental work at this stage has been focussed on two selected pulverised woods: 'Haernoesand-Haesselby' and 'Haernoesand-Fransson' which have the same chemical composition but have different particle shapes and size distributions. During the experiments, the physical characteristics of these pulverised woods are studied using different techniques such as standard vibrating sieves, microscopic images and an aerodynamic classifier 'Aeroklass' developed at TPS. The measurements of the pulverised wood flames generated by these selected pulverised woods are carried out in the TPS laboratory vertical furnace. The in-flame gas and solid samplings are carried out at several cross-sections along the furnace using a water-cooled gas and solid sampling probe. The extent of combustion is measured through the analysis of captured gaseous and solid products. The experimental results show that the experimental furnace and measurement techniques applied in this study are capable to capture the important differences in flame properties due to firing two different pulverised woods and provide necessary in-flame measured experimental data to validate the CFD models that can be used for the simulation of pulverised wood combustion in industrial furnace and boilers. This work clearly demonstrates that the physical characteristics of a pulverised wood such as particle size distribution and particle shape have significant impact on its combustion behaviour. Thus appropriate modelling for non-spherical wood particles is necessary in order to achieve successful numerical simulation for pulverised wood flames.

Lixin Tao [TPS Termiska Processer AB, Nykoeping (Sweden)

2004-01-01

229

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1996-05-17

230

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,...

231

An experimental investigation of pump as turbine for micro hydro application  

Science.gov (United States)

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.

>N Raman, I Hussein,

2013-06-01

232

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

Directory of Open Access Journals (Sweden)

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

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

2003-01-01

233

Experimental investigation of the wake behind a solid disk  

Energy Technology Data Exchange (ETDEWEB)

The flow past a solid circular disk placed in time-dependent approaching stream velocity was investigated experimentally. The model was near-impulsively started from rest and moved at a constant speed. The wake behind the disk remained axisymmetric when the disk was traversed for a short distance. The scaling effect of varying the acceleration rate and the subsequent constant velocity on the wake evolution was investigated by detailed flow visualizations. The drag measurement indicated an initial maximum force dependent on the acceleration rate before it decreased toward the quasi-steady value. The model was subsequently decelerated at various rates, either to rest or to a second constant velocity. The wake overtook the disk in most cases depending of the values of both deceleration rate and velocity ratio. The force measurement showed that the drag acting on the disk became negative shortly after the onset of deceleration and reached its most negative value approximately at the end of the deceleration. The peak negative drag correlated with the deceleration rate. During the deceleration to a second velocity the drag became negative even when the vortex structure remained downstream of the disk. When the disk was subjected to constant speeds for a prolonged time, onset of asymmetry of the vortex structure occurred, eventually leading to a three-dimensional wake. Finally, the wake behind the disk was compared with the two-dimensional counterpart, using a rectangular flat plate. One of the prime motivations for studying the wake behind bluff bodies during acceleration and deceleration phases is to achieve a better understanding of the unsteady flow phenomena associated with the opening and early phase of deceleration of a parachute.

Balligand, H.; Higuchi, Hiroshi [Syracuse Univ., NY (United States). Dept. of Mechanical, Aerospace and Mfg. Engineering

1993-12-01

234

Experimental investigation of hydraulic criteria in the fishways  

International Nuclear Information System (INIS)

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

2002-01-01

235

Experimental investigation of hydraulic criteria in the fishways  

Energy Technology Data Exchange (ETDEWEB)

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

Kurdistani, S.M. [Khouzestan Water and Power Authority (K.W.P.A.), Ahwaz (Iran, Islamic Republic of); Bajestan, M.S. [Univ. of Shahid-Chamran, Ahwaz (Iran, Islamic Republic of)

2002-06-15

236

Experimental and numerical investigation of interactions between above and below ground drainage systems.  

UK PubMed Central (United Kingdom)

This paper presents the results of the experimental and numerical investigation of interactions between surface flood flow in urban areas and the flow in below ground drainage systems (sewer pipes and manholes). An experimental rig has been set up at the Water Engineering Laboratory at the University of Sheffield. It consists of a full scale gully structure with inlet grating, which connects the 8 m(2) surface area with the pipe underneath that can function as an outfall and is also further connected to a tank so that it can come under surcharging conditions and cause outflow from the gully. A three-dimensional CFD (Computational Fluid Dynamics) model has been set up to investigate the hydraulic performance of this type of gully inlet during the interactions between surface flood flow and surcharged pipe flow. Preliminary results show that the numerical model can replicate various complex 3D flow features observed in laboratory conditions. This agreement is overall better in the case of water entering the gully than for the outflow conditions. The influence of the surface transverse slope on flow characteristics has been demonstrated. It is shown that re-circulation zones can form downstream from the gully. The number and size of these zones is influenced by the transverse terrain slope.

Djordjevi? S; Saul AJ; Tabor GR; Blanksby J; Galambos I; Sabtu N; Sailor G

2013-01-01

237

Experimental investigation of design parameters on dry powder inhaler performance.  

UK PubMed Central (United Kingdom)

The study aims to investigate the impact of various design parameters of a dry powder inhaler on the turbulence intensities generated and the performance of the dry powder inhaler. The flow fields and turbulence intensities in the dry powder inhaler are measured using particle image velocimetry (PIV) techniques. In vitro aerosolization and deposition a blend of budesonide and lactose are measured using an Andersen Cascade Impactor. Design parameters such as inhaler grid hole diameter, grid voidage and chamber length are considered. The experimental results reveal that the hole diameter on the grid has negligible impact on the turbulence intensity generated in the chamber. On the other hand, hole diameters smaller than a critical size can lead to performance degradation due to excessive particle-grid collisions. An increase in grid voidage can improve the inhaler performance but the effect diminishes at high grid voidage. An increase in the chamber length can enhance the turbulence intensity generated but also increases the powder adhesion on the inhaler wall.

Ngoc NT; Chang L; Jia X; Lau R

2013-09-01

238

Border collision route to quasiperiodicity: Numerical investigation and experimental confirmation.  

UK PubMed Central (United Kingdom)

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.

Zhusubaliyev ZT; Mosekilde E; Maity S; Mohanan S; Banerjee S

2006-06-01

239

Glulam-concrete composites: experimental investigation into the connection system  

Directory of Open Access Journals (Sweden)

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 paper 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.

José Luiz Miotto; Antonio Alves Dias

2011-01-01

240

Glulam-concrete composites: experimental investigation into the connection system  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english 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 paper 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 (more) 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.

Miotto, José Luiz; Dias, Antonio Alves

2011-03-01

 
 
 
 
241

Border Collision Route to Quasiperiodicity: Numerical Investigation and Experimental Confirmation  

DEFF Research Database (Denmark)

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

Zhusubaliyev, Zhanybai; Mosekilde, Erik

2006-01-01

242

Experimental investigation of NOx emissions in oxycoal combustion  

Energy Technology Data Exchange (ETDEWEB)

This work presents the results of an experimental investigation on NOx emissions from coal combustion in a pilot scale test facility. Three oxidiser atmospheres have been compared, namely air, CO{sub 2}/O{sub 2}, and O{sub 2} enriched recirculated flue gas. NOx emissions from two different combustion modes have been studied, swirl flame and flameless combustion. The influence of the burner oxygen ratio and the oxidiser O{sub 2} concentration on NOx formation and reduction have been analysed. With increasing burner oxygen ratio, an increase of NOx emissions has been obtained for air and CO{sub 2}/O{sub 2} in both, swirl flame and flameless combustion. In case of the swirl flame, flue gas recirculation leads to a reduction of NOx emissions up to 50%, whereas in case of flameless combustion this reduction is around 40% compared to CO{sub 2}/O{sub 2}. No significant impact of the oxidiser O{sub 2} concentration in the CO{sub 2}/O{sub 2} mixture on NOx emissions is observed in the range between 18 and 27 vol.% in swirl flames. An analysis of NOx formation and reduction mechanisms showed, that the observed reduction of NOx emissions by flue gas recirculation cannot be attributed to the reduction of recirculated NOx alone, but also to a reduced conversion of fuel-N to NO. 33 refs., 7 figs., 4 tabs.

Hannes Stadler; Dominik Christ; Martin Habermehl; Peter Heil; Arno Kellermann; Andreas Ohliger; Dobrin Toporov; Reinhold Kneer [RWTH Aachen University, Aachen (Germany). Institute of Heat and Mass Transfer

2011-04-15

243

Experimental investigation of the origin of the Ti K?'' satellites  

International Nuclear Information System (INIS)

[en] The Ti K?'' satellite is investigated using a Johann-type spectrometer on the BL15XU undulator beam line of SPring-8 at excitation energies between 4996 and 7000 eV. The intensity of the K?'' satellite relative to that of K?1,2 exhibits an abrupt jump from 0% to ?1% in a range of 10 eV around an excitation energy of 5010 eV. The energy range to reach saturation is ?500 eV. The creation of spectator holes is implicated to be due to shake-up processes, inducing the emergence of the K?'' satellite. The onset energy for the appearance of the satellite is 5011.0 eV±0.8 eV, corresponding to the [1s3p] double-ionization threshold energy by a Z+1 approximation. The experimental results obtained in this work confirm that the K?'' satellite originates from a 3p spectator hole, as predicted theoretically by Scott [ Phys. Rev. A 34, 4438 (1986)

2004-01-01

244

Experimental Investigation On Design Of High Pressure Steam Turbine Blade  

Directory of Open Access Journals (Sweden)

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.

SUBRAMANYAM PAVULURI, DR. A. SIVA KUMAR

2013-01-01

245

Application of Different Mixing Systems for the Batch Cultivation of the Saccharomyces cerevisiae. Part I: Experimental Investigations and Modelling  

Directory of Open Access Journals (Sweden)

Full Text Available Experimental investigations in different mixing conditions (impulse and vibromixing) in a Saccharomyces cerevisiae batch cultivation are presented in this paper. The investigation is carried out in a 5 l laboratory bioreactor (working volume 3 l). Mathematical models of the process for the two mixing systems are developed. The obtained results have shown that the models are adequate and will be used for process optimisation for the two mixing systems.

Uldis Viesturs; Andrejs Berzins; Juris Vanags; Stoyan Tzonkov; Tatiana Ilkova; Mitko Petrov; Tania Pencheva

2009-01-01

246

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

International Nuclear Information System (INIS)

[en] 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

1988-01-01

247

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)

2001-01-01

248

Experimental investigation of the backbending phenomenon in the Os region  

International Nuclear Information System (INIS)

[en] In the first part several models and theoretical formationa are discussed to explain the backbending effect. A short description of the apparatus for the measurements follows. Then the measurements on the even nuclei sup(182,184)Os and on the odd nuclei sup(181,183)Os and 181Re are discussed, which were investigated by in-beam spectroscopy. The rotational states of these nuclei were populated up to high spin states by the reactions 182W(?,5n)181Os, 186W(?,8n)182Os, 184W(?,5n)183Os, 186W(?,6n)184Os and 181Ta(?,4n)181Re. The ?-bombardement energies varied from 54 to 106. ?-single spectra, ?-?-coincidence spectra, angular distributions and time spectra were measured to get the energy levels of the rotational bands. The backbending curves which follow from these experimental results were discussed in the Rotation-Alignment model. (orig./WL)[de] Im ersten Teil der vorliegenden Arbeit wurden verschiedene Modelle und theoretische Grundlagen diskutiert, die insbesondere zum Verstaendnis des Backbending-Effektes beitragen sollten. Es folgte eine kurze Beschreibung der Apparatur mit der die Messungen ausgefuehrt wurden. Anschliessend wurden die Messungen an den geraden Kernen sup(182,184)Os und den ungeraden Kernen sup(181,183)Os und 181Re diskutiert, die in-beam ?-spektroskopisch untersucht worden sind. Die Rotationszustaende dieser Kerne wurden mit Hilfe der Reaktionen 182W(?,5n)181Os, 186W(?,8n)182Os, 184W(?,5n)183Os, 186W(?,6n)184Os und 181Ta(?,4n)181Re bis zu hohen Drehimpulsen bevoelkert. Die ?-Teilchen Energie variierte von 54 - 106 MeV. Fuer die Aufstellung der Niveauschemata der Rotationsbanden der oben erwaehnten Kerne wurden ?-Einzelspektren, ?-?-Koinzidenzspektren, ?-Winkelverteilungen und Zeitspektren der Uebergaenge gemessen. Die aus den experimentellen Ergebnissen hergeleiteten Backbendingkurven wurden mit Hilfe des Rotation Alignment Modells diskutiert und interpretiert. (orig./WL)

1976-01-01

249

An experimental investigation of flow past a dual step cylinder  

Science.gov (United States)

Flow development in the wake of a dual step cylinder has been investigated experimentally using Laser Doppler Velocimetry and flow visualization. The dual step cylinder model is comprised of a large diameter cylinder ( D) mounted at the mid-span of a small diameter cylinder ( d). The experiments have been performed for a Reynolds number (Re D ) of 1,050, a diameter ratio ( D/d) of 2, and a range of large cylinder aspect ratios ( L/D). The results show that the flow development is highly dependent on L/D. The following four distinct flow regimes can be identified based on vortex dynamics in the wake of the large cylinder: (1) for L/D ? 15, three vortex shedding cells form in the wake of the large cylinder, one central cell bounded by two cells of lower frequency, (2) for 8 < L/D ? 14, a single vortex shedding cell forms in the wake of the large cylinder, (3) for 2 < L/D ? 6, vortex shedding from the large cylinder is highly three-dimensional. When spanwise vortices are shed, they deform substantially and attain a hairpin shape in the near wake, (4) for 0.2 ? L/D ? 1, the large cylinder induces vortex dislocations between small cylinder vortices. The results show that for Regimes I to III, on the average, the frequency of vortex shedding in the large cylinder wake decreases with L/D, which is accompanied by a decrease in coherence of the shed vortices. In Regime IV, small cylinder vortices connect across the large cylinder wake, but these connections are interrupted by vortex dislocations. With decreasing L/D, the frequency of dislocations decreases and the dominant frequency in the large cylinder wake increases toward the small cylinder shedding frequency.

Morton, Chris; Yarusevych, Serhiy

2012-01-01

250

Experimental and computational investigation of local scour around bridge piers  

Science.gov (United States)

Experiments and numerical simulations are carried out to study clear-water scour around three bridge piers with cylindrical, square, and diamond cross-sectional shape, respectively. To handle movable-bed channels with embedded hydraulic structures, the fluid-structure interaction curvilinear immersed boundary (FSI-CURVIB) method is employed. The hydrodynamic model solves the unsteady Reynolds-averaged Navier-Stokes (URANS) equations closed with the k-? turbulence model using a second-order accurate fractional step method. Bed erosion is simulated by solving the sediment continuity equation in the bed-load layer using a second-order accurate unstructured, finite-volume formulation with a sand-slide, bed-slope-limiting algorithm. Grid sensitivity studies are carried out to investigate the effect of grid resolution on the predictive capability of the model. Comparisons of the simulations with the experimental data show that for all three cases the agreement is reasonable. A major finding of this work, however, is that the predictive capability of the URANS morphodynamic model improves dramatically for the diamond shape pier for which sediment transport is driven primarily by the shear layers shed from the pier sharp edges. For piers with blunt leading edge, on the other hand, as the circular and square shapes, the URANS model cannot resolve the energetic horseshoe vortex system at the pier/bed junction and thus significantly underpredicts both the scour depth at the nose of the pier and the rate of scour growth. It is also shown that ad hoc empirical corrections that modify the calculated critical bed shear stress to enhance scour rate in the pier leading edge need to be applied with caution as their predictive capabilities are not universal but rather depend on the pier shape and the region of the flow.

Khosronejad, Ali; Kang, Seokkoo; Sotiropoulos, Fotis

2012-03-01

251

Experimental investigation of critical flow of supercritical carbon dioxide  

Science.gov (United States)

A blowdown facility (0.125 m3) has been built to perform measurements of the critical flow rate of carbon dioxide over a wide range of conditions up to a supercritical pressure of 240 bars and up to a supercritical temperature of 260°C, i.e. three times the critical pressure and two times the critical temperature. The influence of the rupture geometry was investigated using a set of exit pipes with varying entrance shape, roughness and length to diameter ratio ranging from 3.7 to 168. The study showed that a rough sharp edge entrance tube had a lower critical mass flow rate compared to a smooth round entrance tube. For length to diameter ratios larger than 14.7, although two-phase effects were observed, the fluid behavior could be accurately modeled using a homogeneous equilibrium model with friction. For length to diameter ratio smaller than 14.7, the critical mass flux results exhibited a plateau, indicating that the critical mass flow rate was governed by the vena contracta. Stagnation pressure, stagnation temperature and mass time traces were scaled successfully using the initial mass and the initial mass flow rate. An exception was observed for the high density low temperature case due to non equilibrium effects occurring within the vessel. The compressibility of the flow in association with the contraction induced multidimensional and repetitive shock structures within the tube. These have been predicted with computational fluid dynamics modeling for perfect gas conditions. To measure experimentally the fluid state within the tube, an optical absorption technique has been developed, calibrated and tested in two geometries and during an integral blowdown test. Results showed that this new technique lead to the correct qualitative trends in the pressure measurements but that it needed to be calibrated against a more accurate high pressure database obtained for carbon dioxide.

Mignot, Guillaume Paul H.

252

Significance of different animal species in experimental models for in vivo investigations of hematopoiesis  

Directory of Open Access Journals (Sweden)

Full Text Available Numerous discoveries in medicine are results of experiments on different animal species. The most frequently used animals in hematopoiesis investigations are laboratory mice and rats, but so-called big animals, such as pigs, sheep, cats, dogs, and monkeys, evolution-wise closer to humans have a place in experimental hematology as well. The specific problematics of a certain animal specie can lead to fundamental knowledge on certain aspects of the process of hematopoiesis end the biology of stem cells in hematopoiesis. Furthermore, comparative investigations of certain phenomena in different species help in the recognition of the general rules in the living world. In the area f preclinicalinvesti- gations, animal models are an inevitable step in studies of transplantation biology of stem cells in hematopoiesis, as well as in studies of biologically active molecules which have an effect on the hematopoietic system. Knowledge acquired on animal models is applied in both human and veterinary medicine.

Kova?evi?-Filipovi? Milica; Boži? Tatjana P.; Stevanovi? Jelka Ž.

2004-01-01

253

Horonobe Underground Research Laboratory project investigation report for the 2008 fiscal year  

International Nuclear Information System (INIS)

The Horonobe Underground Research Laboratory Project is planned to extend over a period 20 years. The investigations will be conducted in three phases, namely 'Phase 1: Surface-based investigations' 'Phase 2: Construction Phase' (investigations during construction of the underground facilities) and 'Phase 3: Operation phase' (research in the underground facilities). This report summarizes the results of the investigations for the 2008 fiscal year (2008/2009), the 4th year of the Phase 2 investigations. The investigations, which are composed of 'Geoscientific research' and 'R and D on geological disposal technology', were carried out according to 'Horonobe Underground Research Laboratory Project Investigation Program for the 2008 Fiscal year'. The results of these investigations, along with the results which were obtained in other departments of Japan Atomic Energy Agency (JAEA), are properly offered to the implementations and the safety regulations. For the sake of this, JAEA has proceeded with the project in collaboration with experts from domestic and overseas research organisations. (author)

2009-01-01

254

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

1984-01-01

255

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

Energy Technology Data Exchange (ETDEWEB)

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.

Endebrock, E.G.; Dove, R.C.; Dunwoody, W.E.

1984-01-01

256

Experimental and Numerical Investigation of Flows in Expanding Channels  

Energy Technology Data Exchange (ETDEWEB)

We present an experimental realization of the classical Jeffery-Hamel flows inside a wedge-shaped channel. We compare the measured velocity fields with the predictions of Jeffery-Hamel theory. A detailed experimental study of bifurcation diagrams for the solutions reveals the absolute stability of the pure outflow solution and an interesting hysteretic structure for bifurcations. We also observe a multiple vortex flow regime predicted earlier numerically and analytically. Experimental studies of the stability of the flow to perturbations at the channel exit are also conducted.

Vorobieff, Peter; Putkaradze, Vakhtang

2008-10-24

257

Modeling and experimental investigations of x-ray lasers in Russian Federal Nuclear Center-VNIIEF  

Science.gov (United States)

The results of modeling and experimental investigations on the laboratory x-ray laser in RFNC-VNIIEF are presented. The computational model and TRANS computer code of transient amplified spontaneous emission (ASE) have been developed. The actual 3D medium, random polarization source, diffraction, refraction, gain with saturation, scattering by fluctuations of density can taken into account in the model. The 3D calculations of ASE in a Ne-like titanium x-ray laser with transient collisional excitation are presented. Results of experiments are described on Ne-like Ge x-ray laser realized at irradiation of the target by radiation of the ISKRA-5 laser facility. The quasi-steady-state ASE generation on 3p,J=0-3s,J=1 transition of Ne-like Ge (19.6 nm) is observed that is the first demonstration of c-ray laser in Russia in laboratory conditions. The divergence of ASE in a direction perpendicular to the target is about 10 mrad, and ASE beam deflection with respect to an optical axis is about 10 mrad. The experimental data are compared with simulation results.

Starikov, Fedor A.; Bessarab, Aleksandr V.; Gasparyan, Petros D.; Kirillov, Gennadi A.; Tokarev, Vladimir A.; Jidkov, Nikolai V.

2003-12-01

258

Experimental and theoretical investigations of the aerodynamics of road vehicles  

Energy Technology Data Exchange (ETDEWEB)

Results of recent studies on vehicle aerodynamics are presented. They indicate the trends of present and future theoretical and experimental work and are expected in the long run to lead to a method of calculating air flow around a vehicle.

Ahmed, S.R.

1980-11-01

259

Numerical and experimental investigations of the pollutant distribution in sewers.  

Science.gov (United States)

Controlling flow and pollutant discharges through sewer networks is required for a number of reasons. In order to accomplish such control, precise knowledge of the hydrodynamic conditions of each candidate measurement location proves critical. The Laboratoire Central dos Ponts et Chaussés has thus become involved in an experimental program on velocity and suspended matter concentration fields. This paper first presents the measurement methods and experimental results obtained before providing and discussing some of the numerical results. PMID:11989896

Jaumouillié, P; Larrarte, F; Milisic, V

2002-01-01

260

Numerical and experimental investigations of the pollutant distribution in sewers.  

UK PubMed Central (United Kingdom)

Controlling flow and pollutant discharges through sewer networks is required for a number of reasons. In order to accomplish such control, precise knowledge of the hydrodynamic conditions of each candidate measurement location proves critical. The Laboratoire Central dos Ponts et Chaussés has thus become involved in an experimental program on velocity and suspended matter concentration fields. This paper first presents the measurement methods and experimental results obtained before providing and discussing some of the numerical results.

Jaumouillié P; Larrarte F; Milisic V

2002-01-01

 
 
 
 
261

Horonobe Underground Research Laboratory project. Investigation report for the 2009 fiscal year  

International Nuclear Information System (INIS)

[en] The Horonobe Underground Research Laboratory Project is planned to extend over a period 20 years. The investigations will be conducted in three phases, namely 'Phase 1: Surface-based investigations', 'Phase 2: Construction Phase' (investigations during construction of the underground facilities) and 'Phase 3: Operation phase' (research in the underground facilities). This report summarizes the results of the investigations for the 2009 fiscal year (2009/2010). The investigations, which are composed of 'Geoscientific research' and 'R and D on geological disposal technology', were carried out according to 'Horonobe Underground Research Laboratory Project Investigation Program for the 2009 Fiscal year'. The results of these investigations, along with the results which were obtained in other departments of Japan Atomic Energy Agency (JAEA), are properly offered to the implementations and the safety regulations. For the sake of this, JAEA has proceeded with the project in collaboration with experts from domestic and overseas research organisations. (author)

2010-01-01

262

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

International Nuclear Information System (INIS)

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

2012-01-01

263

Experimental Investigations and Modelling Studies of Ozone Producing Corona Discharges  

Science.gov (United States)

The ozone generation by negative corona discharge in coaxial cylindrical system of electrodes have been studied experimentally in Ar+O2 and N2+O2 mixtures. Both in argon and nitrogen mixtures with oxygen the monotonous decrease in ozone concentration [O3] was observed at decreasing oxygen content in mixtures and the constant input energy density ?. The rate coefficients for the ozone generation and ozone decomposition were obtained by fitting experimentally measured data [O3]= f(?) with Vasiljev-Eremin formula. The calculated rate coefficient for ozone generation in N2+O2 mixtures at low content of oxygen (below 20%) was found considerably higher than that in Ar+O2 mixtures. Increase in the rate coefficients for ozone generation and decomposition was observed with decreasing content of oxygen in both mixtures. The experimental results are in qualitative agreement with the simple model incorporating five main chemical processes in mechanism of ozone generation.

Mason, N. J.; Skalny, J. D.; Hadj-Ziane, S.

2002-01-01

264

Experimental investigation of enhanced microwave scattering with time-of-flight resolution  

Energy Technology Data Exchange (ETDEWEB)

In small tokamak and laboratory plasmas, the radar version of the enhanced scattering diagnostic permits observation of small-scale density fluctuations with a high spatial and wavenumber resolution. The method is experimentally studied on a radio frequency generated linear laboratory plasma at which externally excited lower-hybrid waves are diagnosed.

Bruesehaber, B.; Kraemer, M.

1994-01-01

265

Experimental investigation of enhanced microwave scattering with time-of-flight resolution  

Energy Technology Data Exchange (ETDEWEB)

In small tokamak and laboratory plasmas, the radar version of the enhanced scattering diagnostic permits observation of small-scale density fluctuations with a high spatial and wavenumber resolution. The method is experimentally studied on an r.f. generated linear laboratory plasma at which externally excited lower-hybrid waves are diagnosed. (author). 2 refs, 6 figs.

Bruesehaber, B.; Kraemer, M. [Bochum Univ. (Germany). Inst. fuer Experimentalphysik 3

1994-12-31

266

Subjected to parliament: the laboratory of experimental medicine and the animal body.  

UK PubMed Central (United Kingdom)

In 'Sacrifice and the Transformation of the Animal Body into a Scientific Object' Michael Lynch (1988) explores how the animal body is transformed into a scientific object in the laboratory. How did the laboratory become a (relatively) closed space in which scientists, the experts, were delegated the task of negotiating and transforming the interpretative sense of the animal--from sentient beings to analytic objects--as tools in a scientific machinery? By exploring a parliamentary controversy on experimental medicine at the turn of the 20th century I argue that this depended on a reworking of the status of the animal body, as well as the status of the laboratory. Crucial to this was social theory; specifically, utilitarian reasoning. Thus, what we need to study--this paper argues--is not simply the ways in which the practices of annual experimentation were met with opposition and critiques, but also how these practices came to be culturally and politically accepted, and what this implied for science - society relations. In analysing this controversy, the author attends to recent turn to politics in STS and argue for the significance of studying conventional political sites such as 'Parliament' and the role that social theory plays in renegotiating and remaking sites and objects.

Asdal K

2008-12-01

267

An experimental investigation on heat transfer in rotating coolant channels  

Science.gov (United States)

This paper deals with a facility and an experimental technique for researching the heat transfer of coolant channels in the rotating turbine blade, and presents the preliminary results of the convective coefficient of the flow parallel to the axis in the rotating conditions. The results show that the effect of rotating on heat transfer is highly enhanced by centrifugal and Coriolis forces.

Wang, Baoguan; Ding, Xiaojiang

1989-07-01

268

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

UK PubMed Central (United Kingdom)

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.

Xiao SH; Utzinger J; Tanner M; Keiser J; Xue J

2013-05-01

269

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

Science.gov (United States)

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

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

2013-01-23

270

Laboratory Experiments and Investigations on the Reaction Rates of Mg-sulfates Under Mars Relevant Conditions  

Science.gov (United States)

Large deposits of hydrous Mg-sulfates was identified on Mars by orbital remote sensing (OMEGA on Mars Express and CRISM on Mars Reconnaissance Orbiter). Kieserite (MgSO4.H2O) and a non-specific “polyhydrated sulfates” are among the most observed and widely distributed sulfates (Bibring et al., 2005, Murchie et al., 2007). They frequently co-exist (Gendrin et al., 2005) and sometimes occur in alternative stratigraphic layers (Roach et al., 2008). Mg-sulfates were suggested, by compositional correlations and mineral models, to exist in Meridiani outcrops (Clark et al., 2005) and in rocks and regolith at Gusev (Squyres et al., 2006, Haskin et al., 2005, Wang et al., 2006, 2008); but no information on the hydration state of these sulfates can be extracted. We have conducted 188 experiments to investigate the stability fields and phase transition pathways of hydrous Mg-sulfates (Wang et al., 2009). In addition, we can extract the information on the reaction rates of five important dehydration and rehydration processes involved in these experiments. Our experiments were done at four temperatures (50°C, 21°C, 5°C, and -10°C) and ten relative humidity levels, with five hydrous Mg-sulfate species as starting phases. The rate information was extracted from the mineral identifications of the intermediate reaction products, measured by non-invasive Raman spectroscopy at regular time intervals during the entire duration of experiments (tens’ thousands hours). The rates for five processes are all strongly controlled by temperatures. We found that the experimental results match Arrhenius equation very well, thus the rate constants for dehydration and rehydration processes of Mg-sulfates at lower temperatures (down to 180K) can be approximately estimated by using the experimentally derived pre-exponential factor(s) and activation energy(s). In this study, only the orders of magnitudes for reaction rate ratios at different temperatures were considered. The estimated reaction rate ratios at different temperatures for five important processes helped us to understand the stable, especially the metastable, Mg-sulfate species that could be seen at Mars surface in non-polar regions during a moderate obliquity period. Therefore in addition to exam the spectral similarity, we now can use the knowledge gained through the laboratory experiments on stability field, phase transition pathway, and reaction rate of Mg-sulfates to evaluate the realistic mineral candidates for “polyhydrated sulfates”, that were so widely observed on Mars by OMEGA and CRISM. Furthermore, we will be able to investigate the formation mechanism of alternative stratigraphic layers of sulfates on Mars and the paleo-climatic conditions that they may imply.

Wang, A.; Freeman, J. J.

2009-12-01

271

Precise experimental investigation of eigenmodes in a planar ion crystal.  

Science.gov (United States)

The accurate characterization of eigenmodes and eigenfrequencies of two-dimensional ion crystals provides the foundation for the use of such structures for quantum simulation purposes. We present a combined experimental and theoretical study of two-dimensional ion crystals. We demonstrate that standard pseudopotential theory accurately predicts the positions of the ions and the location of structural transitions between different crystal configurations. However, pseudopotential theory is insufficient to determine eigenfrequencies of the two-dimensional ion crystals accurately but shows significant deviations from the experimental data obtained from resolved sideband spectroscopy. Agreement at the level of 2.5×10(-3) is found with the full time-dependent Coulomb theory using the Floquet-Lyapunov approach and the effect is understood from the dynamics of two-dimensional ion crystals in the Paul trap. The results represent initial steps towards an exploitation of these structures for quantum simulation schemes. PMID:23368557

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

2012-12-28

272

Precise experimental investigation of eigenmodes in a planar ion crystal  

CERN Document Server

The accurate characterization of eigenmodes and eigenfrequencies of two-dimensional ion crystals provides the foundation for the use of such structures for quantum simulation purposes. We present a combined experimental and theoretical study of two-dimensional ion crystals. We demonstrate that standard pseudo-potential theory accurately predicts the positions of the ions and the location of structural transitions between different crystal configurations. However, pseudo-potential theory is insufficient to determine eigenfrequencies of the two-dimensional ion crystals accurately but shows significant deviations from the experimental data obtained from resolved sideband spectroscopy. Agreement at the level of 2.5 x 10^(-3) is found with the full time-dependent Coulomb theory using the Floquet-Lyapunov approach and the effect is understood from the dynamics of two-dimensional ion crystals in the Paul trap.

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

2012-01-01

273

Precise Experimental Investigation of Eigenmodes in a Planar Ion Crystal  

Science.gov (United States)

The accurate characterization of eigenmodes and eigenfrequencies of two-dimensional ion crystals provides the foundation for the use of such structures for quantum simulation purposes. We present a combined experimental and theoretical study of two-dimensional ion crystals. We demonstrate that standard pseudopotential theory accurately predicts the positions of the ions and the location of structural transitions between different crystal configurations. However, pseudopotential theory is insufficient to determine eigenfrequencies of the two-dimensional ion crystals accurately but shows significant deviations from the experimental data obtained from resolved sideband spectroscopy. Agreement at the level of 2.5×10-3 is found with the full time-dependent Coulomb theory using the Floquet-Lyapunov approach and the effect is understood from the dynamics of two-dimensional ion crystals in the Paul trap. The results represent initial steps towards an exploitation of these structures for quantum simulation schemes.

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

2012-12-01

274

Precise experimental investigation of eigenmodes in a planar ion crystal.  

UK PubMed Central (United Kingdom)

The accurate characterization of eigenmodes and eigenfrequencies of two-dimensional ion crystals provides the foundation for the use of such structures for quantum simulation purposes. We present a combined experimental and theoretical study of two-dimensional ion crystals. We demonstrate that standard pseudopotential theory accurately predicts the positions of the ions and the location of structural transitions between different crystal configurations. However, pseudopotential theory is insufficient to determine eigenfrequencies of the two-dimensional ion crystals accurately but shows significant deviations from the experimental data obtained from resolved sideband spectroscopy. Agreement at the level of 2.5×10(-3) is found with the full time-dependent Coulomb theory using the Floquet-Lyapunov approach and the effect is understood from the dynamics of two-dimensional ion crystals in the Paul trap. The results represent initial steps towards an exploitation of these structures for quantum simulation schemes.

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

2012-12-01

275

Modeling and experimental investigations of keyhole laser welding  

Science.gov (United States)

In the paper are presented new analytical modeling of deep penetration laser welding and its experimental verification. The model is an extension of analytical model of 1973. The model allows the derivation of penetration and width of melting zone caused by moving laser beam. As a result there was derived dependences of penetration length, width of the melting zone and aspect ratio of the zone as a function of welding speed and laser power. The theoretical results was compared with experimental data. The results allows the determination of optimal conditions for keyhole effect. Results of the modelling are expressed in non dimensional parameters therefore can be applied to any metals and alloys for design of laser welding parameters.

Mucha, Zygmunt; Mulczyk, Krystian

2013-01-01

276

Experimental investigations on the first Townsend coefficient in pure isobutane  

Science.gov (United States)

In this work we present results of the first Townsend coefficient (?) in pure isobutane by measuring the current growth as a function of the electric field strength in a pulsed irradiation regime. A Resistive Plate Chamber (RPC)-like configuration was used. To validate this method, as well as to crosscheck the experimental apparatus, measurements of the ? parameter were firstly carried out with pure nitrogen and the results compared to the accurate data available in the literature. The data obtained with isobutane in a field range from 145 Td up to 200 Td were well-matched to those calculated with Magboltz versions 2.7.1 and 2.8.6. The experimental consistency of these results with other published data in the range of 550-1300 Td was very good, as demonstrated by the use of the Korff parameterization.

Lima, I. B.; Mangiarotti, A.; Vivaldini, T. C.; Gonçalves, J. A. C.; Botelho, S.; Fonte, P.; Takahashi, J.; Tarelho, L. V.; Bueno, C. C.

2012-04-01

277

Comparing field investigations with laboratory models to predict landfill leachate emissions  

International Nuclear Information System (INIS)

Investigations into laboratory reactors and landfills are used for simulating and predicting emissions from municipal solid waste landfills. We examined water flow and solute transport through the same waste body for different volumetric scales (laboratory experiment: 0.08 m3, landfill: 80,000 m3), and assessed the differences in water flow and leachate emissions of chloride, total organic carbon and Kjeldahl nitrogen. The results indicate that, due to preferential pathways, the flow of water in field-scale landfills is less uniform than in laboratory reactors. Based on tracer experiments, it can be discerned that in laboratory-scale experiments around 40% of pore water participates in advective solute transport, whereas this fraction amounts to less than 0.2% in the investigated full-scale landfill. Consequences of the difference in water flow and moisture distribution are: (1) leachate emissions from full-scale landfills decrease faster than predicted by laboratory experiments, and (2) the stock of materials remaining in the landfill body, and thus the long-term emission potential, is likely to be underestimated by laboratory landfill simulations.

2009-01-01

278

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.

1997-01-01

279

Experimental investigation of dynamic pressure loads during dam break  

CERN Document Server

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

Lobovský, Libor; Castellana, Filippo; Mas-Soler, Jordi; Souto-Iglesias, Antonio

2013-01-01

280

Experimental Investigation of In Situ Cleanable HEPA Filters  

Energy Technology Data Exchange (ETDEWEB)

Savannah River Technology Center (SRTC) located at Westinghouse Savannah River Site (WSRS) is currently conducting research and development experimentation to develop a replacement of the conventional high efficiency particulate air (HEPA) filter system currently used by commercial industry and DOE facilities. It has been determined that a cleanable or regenerable HEPA filter system may be the most cost effective and efficient HEPA filter system to be considered for use in a more safe and reliable work environment.

Hatcher, S.A.

2001-04-11

 
 
 
 
281

Experimental Investigation of In Situ Cleanable HEPA Filters  

International Nuclear Information System (INIS)

[en] Savannah River Technology Center (SRTC) located at Westinghouse Savannah River Site (WSRS) is currently conducting research and development experimentation to develop a replacement of the conventional high efficiency particulate air (HEPA) filter system currently used by commercial industry and DOE facilities. It has been determined that a cleanable or regenerable HEPA filter system may be the most cost effective and efficient HEPA filter system to be considered for use in a more safe and reliable work environment

2001-01-01

282

Theoretical and experimental investigations on incompressible flow through labyrinths  

Energy Technology Data Exchange (ETDEWEB)

A low, well defined and cavitation free flow has to be achieved for the leakage of coolant sodium in the annular space between the grid plate sleeve and foot of the core subassembly in the Prototype Fast Breeder Reactor (PFBR). The leakage flow is accompanied by a corresponding pressure drop which is a function of several parameters including turbulence quantities. Theoretical pressure drops for simple annular seals which offer the least flow resistance are found to be low and incapable of fully serving the intended purpose of reducing the sodium pressure profoundly. On the contrary, labyrinth seals provide intricate passages, offer higher resistance to flow and hence can lead to enhanced pressure drops. This paper formulates a theoretical model for estimating the pressure drop taking place in a labyrinth seal by considering the Darcy losses and the vortex losses occurring inside the cavity of the labyrinth. The latter is indeterminable since the angular velocity of the vortex is not amenable for analytical estimation. Hence a square grooved labyrinth was fabricated and tested at different simulated flow rates of water. From the experimental results, the values of a parameter named vortex coefficient are evaluated to complete the theoretical model. The experimental pressure drops are compared with the values calculated by other theoretical models. Using the insight gained, a novel profile of labyrinth is designed. The vortex coefficients for this profile were expectedly and experimentally proved to be higher resulting in its appreciably better performance than the square labyrinth profile.

Asok, S. P.; Arulmurugan, S. [MSEC, Madurai (India); Rajesh, K.; Padmakumar, G.; Govindarajan, S. [IGCAR, Kalpakkam, (India); Sundararajan, T. [Indian Istitute of Tech., Chennai (India); Sankaranarayanasamy, K.; Prabhakar, R.; Vaidyanathan, G. [Regional Engineering College, Trichy (India)

2003-07-01

283

Experimental investigation into infrasonic emissions from atmospheric turbulence.  

UK PubMed Central (United Kingdom)

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

Shams QA; Zuckerwar AJ; Burkett CG; Weistroffer GR; Hugo DR

2013-03-01

284

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 jet geometry are presented.

2010-01-01

285

Facilities for post-irradiation examination of experimental fuel elements at Chalk River Nuclear Laboratories  

International Nuclear Information System (INIS)

Expansion of post-irradiation facilities at the Chalk River Nuclear Laboratories and steady improvement in hot-cell techniques and equipment are providing more support to Canada's reactor fuel development program. The hot-cell facility primarily used for examination of experimental fuels averages a quarterly throughput of 40 elements and 110 metallographic specimens. New developments in ultrasonic testing, metallographic sample preparation, active storage, active waste filtration, and fissile accountability are coming into use to increase the efficiency and safety of hot-cell operations. (author)

1977-12-02

286

Experimental and climical investigations of a TSH radioimmunoassay  

International Nuclear Information System (INIS)

The system hypothalamus-pitnitary-thyroid was studied in 427 patients by radioimmunological TSH determination prior to i.v. injection of 600 ?g of synthetic TSH and 30 min p.i. Different commercial TSH test kits were used. The RIA was found to be a sensitive indicator of the functional state of the system. Higher accuracy can be achieved by observing certain criteria. The TSH-RIA is a valuable tool for diagnosis and therapy control of thyroid diseases. With some slight methodological modifications, it has become part of the routine programme of the Giessen thyroid laboratory. The RIA is best suited for early detection of disturbances in the pitnitary-thyroid system; it is less efficient in course control of thyroid diseases. It can be carried out within 30 minutes and, except for two withdrawals of blood, imposes no strain on the patient. (orig./MG)

1979-01-01

287

The experimental investigation of the alpha decay of transactinium isotopes  

International Nuclear Information System (INIS)

Current methods and existing experimental facilities to measure the energy spectrum of alpha radiation are described, and a list of recent publication containing compilation on alpha-decay data is given. The review concentrates on the presentation of the current status of alpha decay data of the transactinium isotopes. The values and uncertainties of the absolute energies and the relative intensities of alpha-groups are tabulated. Suggested ''best values'' of decay half-lives of some of the most often used long-lived transactinium isotopes are listed. (author)

1975-11-03

288

Shock induced response of structural systems analytical and experimental investigations  

International Nuclear Information System (INIS)

This contribution refers to the behaviour of reinforced concrete structures impacted by deformable missiles. The difference with hard missile impact problems, about which generally more knowledge exists, are point out. Structural response effects beyond the immediate contact face vicinity, beyond the local load introduction zone - i.e. effects of punching shear, of bending, of vibration transmission etc. - are emphasized. Two- and three-dimensional analytical approaches verified by experimental evaluations are discussed, and typical phenomena of the behaviour of reinforced concrete structures subjected to impact loads are demonstrated. (Author).

1984-01-01

289

Experimental investigation of natural convection losses from open cavities  

Energy Technology Data Exchange (ETDEWEB)

Experimental results for natural convection in a cavity are reported. Both constrained andd unconstrained cavity geometries were studied. Detailed velocity profiles were obtained using Laser doppler velocimetry for Rayleigh numbers between 3 x 10/sup 10/ and 2 x 10/sup 11/, corresponding to a constant elevated wall temperature boundary condition. Characteristics of two-dimensional and three-dimensional flows obtained with dye flow visualization are discussed, including boundary layer transition to turbulence, flow patterns in the cavity, and flow outside of the cavity. Local Nusselt number is correlated with local Rayleigh number for constrained and unconstrained cavities.

Hess, C.F.; Henze, R.H.

1984-05-01

290

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.).

1990-01-01

291

Numerical and experimental investigation of thermal louvers for space applications  

Directory of Open Access Journals (Sweden)

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.

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

2001-01-01

292

Numerical and experimental investigation of thermal louvers for space applications  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english 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.

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

2001-01-01

293

Experimental investigation of delayed self-interference for single photons  

International Nuclear Information System (INIS)

A photon echo experiment has been performed using accumulated highly attenuated laser pulses. We show experimentally that the photon echo process can be performed with, on the average, less than one photon in each pair of excitation pulses. The results support an interpretation where this nonlinear process can be performed with, on the average, less than one photon shared between two of the optical fields involved in the degenerate four-wave-mixing process. Further, we argue that the experiment can be interpreted as a form of delayed self-interference for photon wave packets that do not overlap in both space and time.

2003-01-01

294

Experimental investigation of the transverse SBS excitation in anisotropic crystals  

Energy Technology Data Exchange (ETDEWEB)

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

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

1995-12-31

295

Experimental and numerical investigation of highly absorbing nonlinear organic chromophores  

Science.gov (United States)

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.

Parilov, E.; Potasek, M. J.

2012-02-01

296

Incipient Transient Detection in Reactor Systems: Experimental and Theoretical Investigation  

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-09-27

297

Investigating Climate Change and Reproduction: Experimental Tools from Evolutionary Biology  

Directory of Open Access Journals (Sweden)

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

Vera M. Grazer; Oliver Y. Martin

2012-01-01

298

Experimental investigations of operation of active-bucket excavators  

Energy Technology Data Exchange (ETDEWEB)

The IGD SO AN SSSR research institute developed and successfully tested experimental units of power shovels with buckets equipped with pneumatic picks. The power shovels are used for mining coal and sedimentary rocks with a medium resistance to digging. The power shovels with pneumatic picks were tested in the Kuzbass. Aleurites and sandstones with a resistance to cutting ranging from 50.0 to 77 MPa as well as black coal with a resistance to cutting from 12.0 to 24.5 MPa were mined by power shovels with buckets equipped with pneumatic picks. Operational experience with experimental units showed that using buckets with pneumatic picks successfully replaced explosive fracturing of strong overburden. Duration of the mining cycle decreased; mining efficiency increased. Dynamic loads on structural elements of power shovel were within permissible limits. Dynamic loads caused by operation of pneumatic picks did not negatively influence service life of the power shovels. Noise and dust pollution were within permissible limits. Grain size distribution of overburden mined by excavators with buckets equipped with pneumatic picks improved. 4 refs.

Mattis, A.R.; Shishaev, S.V. (Institut Gornogo Dela (USSR))

1989-01-01

299

Experimental investigation of the steam condensation with air and helium  

Science.gov (United States)

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

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

2013-07-01

300

An experimental investigation of post dryout heat transfer  

International Nuclear Information System (INIS)

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

1983-01-01

 
 
 
 
301

Experimental investigation of a liquid-flooded Ericsson cycle cooler  

Energy Technology Data Exchange (ETDEWEB)

An experimental test program was conducted on a novel Ericsson cycle heat pump. The concept uses liquid flooding of the compressor and expander to approach isothermal compression and expansion processes. Open drive automotive scrolls were used in the experimental system. Numerous experiments were run at various conditions using nitrogen as the refrigerant and alkyl-benzene oil as the flooding liquid. Cooling capacities of over 670 W and volumetric cooling capacities of more than 110 kJ/m{sup 3} were measured. Second law efficiencies of approximately 3% were achieved. Similar to other gas cycles, the cycle performance is very sensitive to the adiabatic efficiencies of the rotating equipment and the performance of the off-the-shelf equipment was not sufficient to achieve high cycle efficiency. In addition, large pressure drops occurred in the system due to the instrumentation used and the long and arduous flow paths. The scroll compressor and expander were found to perform well considering that they were not designed for the operating conditions encountered. (author)

Hugenroth, Jason; Braun, James; Groll, Eckhard; King, Galen [Purdue University, School of Mechanical Engineering, Ray W. Herrick Laboratories, 140 South Intramural Drive, West Lafayette, IN 47907 (United States)

2008-11-15

302

Fish on Prozac: a simple, noninvasive physiology laboratory investigating the mechanisms of aggressive behavior in Betta splendens.  

UK PubMed Central (United Kingdom)

The neuromodulator serotonin is an important regulator of aggressive behavior in vertebrates. Experimentally increasing synaptic levels of serotonin with fluoxetine, a selective serotonin reuptake inhibitor, has been shown to reliably decrease the expression of aggressive behavior. Here, we describe a method by which fluoxetine can be noninvasively administered to male Betta splendens (an attractive model for the study of aggressive behavior) and describe a simple laboratory exercise that allows students to experimentally investigate the physiological mechanisms of aggressive behavior. We demonstrate that relatively short-term exposure (3 h) of male bettas to as little as 3 microg/ml of fluoxetine-treated aquarium water is sufficient to reduce the expression of specific aggressive behaviors. We emphasize the physiological concepts that can be addressed with this exercise, including the role of the serotonergic system in regulating aggression, and the interplay of environmental contaminants and physiology in regulating the expression of behavior. We also highlight important aspects of experimental design. This exercise can be flexibly altered to accommodate one or several laboratory periods. It is also low cost, is low impact to the animals, and requires minimal preparation time for instructors.

Lynn SE; Egar JM; Walker BG; Sperry TS; Ramenofsky M

2007-12-01

303

Fish on Prozac: a simple, noninvasive physiology laboratory investigating the mechanisms of aggressive behavior in Betta splendens  

Science.gov (United States)

The neuromodulator serotonin is an important regulator of aggressive behavior in vertebrates. Experimentally increasing synaptic levels of serotonin with fluoxetine, a selective serotonin reuptake inhibitor, has been shown to reliably decrease the expression of aggressive behavior. Here, we describe a method by which fluoxetine can be noninvasively administered to male Betta splendens (an attractive model for the study of aggressive behavior) and describe a simple laboratory exercise that allows students to experimentally investigate the physiological mechanisms of aggressive behavior. We demonstrate that relatively short-term exposure (3 h) of male bettas to as little as 3 õg/ml of fluoxetine-treated aquarium water is sufficient to reduce the expression of specific aggressive behaviors. We emphasize the physiological concepts that can be addressed with this exercise, including the role of the serotonergic system in regulating aggression, and the interplay of environmental contaminants and physiology in regulating the expression of behavior. We also highlight important aspects of experimental design. This exercise can be flexibly altered to accommodate one or several laboratory periods. It is also low cost, is low impact to the animals, and requires minimal preparation time for instructors.

Sharon E Lynn (The College of Wooster Biology); Joseph M Egar (The College of Wooster Biology); Brian G Walker (Fairfield University Biology); Todd S Sperry (University of Washington Biology); Marilyn Ramenofsky (University of Washington Biology)

2007-12-01

304

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...

305

Bioaccumulation and detoxification processes of Hg in the king scallop Pecten maximus: field and laboratory investigations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Hg bioaccumulation was investigated in the king scallop Pecten maximus in the laboratory and in the field. In controlled conditions, scallops were exposed to 203Hg through seawater, sediment and food in order to determine its uptake and depuration kinetics. In the field, Hg and metallothionein (MT) ...

Metian, Marc; Warnau, Michel; Cosson, Richard; Oberhänsli, François; Bustamante, Paco

306

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

Science.gov (United States)

|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…

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

2008-01-01

307

Airborne Dust Levels Generated during Insulation with MMMF: A Laboratory Investigation.  

Science.gov (United States)

A laboratory study has been undertaken to investigate the potential risks associated with the use of man-made mineral fiber (MMMF) insulation wools. The study comprised an assessment of the MMMF properties which could affect airborne fiber levels and meas...

J. Cherrie R. Stelfox

1990-01-01

308

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

Science.gov (United States)

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…

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

2008-01-01

309

Theoretical and experimental investigation of Chinese evacuated tubular solar collectors  

Energy Technology Data Exchange (ETDEWEB)

For many years evacuated tubular collectors have been marketed in Europe and the USA. These solar collectors are typically designed on the basis of the heat-pipe principle. Recently a number of Chinese firms started mass production of relatively cheap evacuated tubular solar collectors. The firms produce differently designed evacuated tubular solar collectors, e.g. with different absorbers and glass tube diameters with or without reflectors. As opposed to Europe, in Asia evacuated tubular solar collectors have reached such a low price level and such a high efficiency that in certain types of solar heating systems it has become attractive to use these high-efficient solar collectors instead of ordinary flat-plate collectors. At present the suitability of Chinese evacuated tubular solar collectors for different types of solar heating systems under Danish conditions are investigated at the Technical University of Denmark, DTU. The provisional results of these investigations, which are expected to be finished in the spring of 1999, are described in details in this document. The completed investigations indicate that the thermal performance of a small solar domestic hot water system can be improved if the evacuated tubular solar collector is used instead of a traditional flat-plate collector. However, the investigations indicate the price/performance-ratio of typical Danish small solar domestic hot water systems can not be improved by using evacuated tubular solar collectors instead of traditional flat-plate collector. Furthermore, the investigations indicate that it is not as important for the evacuated tubular solar collectors that the solar collectors are installed with `correct` orientation and tilt as it is for flat-plate collectors. The investigations also showed that it is an advantage for solar heating plants with high operation temperature to use high-efficient evacuated tubular solar collectors. (EHS)

Lin Qin; Furbo, S.

1999-06-01

310

Laboratory open-quotes proof of principleclose quotes investigation for the acoustically enhanced remediation technology  

International Nuclear Information System (INIS)

This document describes a three phase program of Weiss Associates which investigates the systematics of using acoustic excitation fields (AEFs) to enhance the in-situ remediation of contaminated soil and ground water under both saturated and unsaturated conditions. The focus in this particular paper is a laboratory proof of principle investigation. The field deployment and engineering viability of acoustically enhanced remediation technology is also examined.

1995-01-01

311

The IAA cosmic dust laboratory: Experimental scattering matrices of clay particles  

Science.gov (United States)

We present the first results of measurements on solid particles performed at the Instituto de Astrof?´sica de Andaluc?´a (IAA) cosmic dust laboratory located in Granada, Spain. The laboratory apparatus measures the complete scattering matrix as a function of the scattering angle of aerosol particles. The measurements can be performed at a wavelength ( ?) of 483, 488, 520, 568, or 647 nm in the scattering angle range from 3° to 177°. Results of special test experiments are presented which show that our experimental results for scattering matrices are not significantly contaminated by multiple scattering and that the sizes/shapes of the particles do not change during the measurements. Moreover, the measured scattering matrix for a sample of green clay particles is compared with measurements previously performed in the Amsterdam light scattering setup for the same sample. New measurements on a white clay sample at 488 and 647 nm are also presented. The apparatus is devoted to experimentally studying the angle dependence of scattering matrices of dust samples of astrophysical interest. Moreover, there is a great interest in similar studies of aerosols that can affect the radiative balance of the atmosphere of the Earth and other planets such as silicates, desert dust, volcanic ashes, and carbon soot particles.

Muñoz, O.; Moreno, F.; Guirado, D.; Ramos, J. L.; Volten, H.; Hovenier, J. W.

2011-01-01

312

Experimental investigation of the Fast-SAGD process  

Energy Technology Data Exchange (ETDEWEB)

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

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

2006-07-01

313

Experimental Investigation of a Finite Circulation Control Wing.  

Science.gov (United States)

This wind tunnel investigation examined the lift, drag, and pitching moment of a 20% thick, 8.5% camber, partial elliptical cross-section, single blowing slot, rectangular, circulation control wing. The aspect ratios tested were 3.71 and 3.99. Variables i...

J. M. Tallarovic

1992-01-01

314

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.

2000-01-01

315

Ethnic Differences in Women's Body Satisfaction: An Experimental Investigation.  

Science.gov (United States)

|Investigates the influence of ethnic differences on women's body satisfaction. Summarizes a study where white and black female undergraduates received bogus positive and negative social feedback. The feedback resulted in corresponding changes in the white females' body satisfaction. Black women were unaffected by the feedback. (MJP)|

Henriques, Gregg R.; And Others

1996-01-01

316

Experimental and numerical investigation of flameless pulverised coal combustion  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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* chem...

Stadler, Hannes Alexander

317

High-temperature electrolysis for large-scale hydrogen production from nuclear energy - experimental investigations  

International Nuclear Information System (INIS)

The Idaho National Laboratory (INL) is currently assessing the feasibility of using solid-oxide-based electrolysis cell technology for high-temperature electrolysis of steam for large scale hydrogen production. In parallel, the INL is studying the simultaneous electrolysis of steam and carbon dioxide for syngas (hydrogen / carbon monoxide mixture) production. When linked to a nuclear power source, this technology provides a carbon neutral means of producing syngas while consuming CO2. The scope of experimental investigations at the INL includes single button cell tests, multi-cell stacks, and multi-stack systems. Multi-cell stack testing used 10 cm x 10 cm (8 cm x 8 cm active area) or 20 cm x 20 cm (18 cm x 18 cm active area) planar cells supplied by Ceramatec, Inc (Salt Lake City, Utah, USA). Multi-stack testing encompassed up to 720 10 cm x 10 cm cells and was conducted in a newly developed 15 kW Integrated Laboratory Scale (ILS) test facility. Gas composition, operating voltage, and operating temperature were varied during testing. The tests were heavily instrumented, and outlet gas compositions were monitored with a gas chromatograph. Results to date show the process to be a promising technique for large-scale hydrogen and syngas production. (author)

2009-01-01

318

High-temperature electrolysis for large-scale hydrogen production from nuclear energy - experimental investigations  

Energy Technology Data Exchange (ETDEWEB)

The Idaho National Laboratory (INL) is currently assessing the feasibility of using solid-oxide-based electrolysis cell technology for high-temperature electrolysis of steam for large scale hydrogen production. In parallel, the INL is studying the simultaneous electrolysis of steam and carbon dioxide for syngas (hydrogen / carbon monoxide mixture) production. When linked to a nuclear power source, this technology provides a carbon neutral means of producing syngas while consuming CO{sub 2}. The scope of experimental investigations at the INL includes single button cell tests, multi-cell stacks, and multi-stack systems. Multi-cell stack testing used 10 cm x 10 cm (8 cm x 8 cm active area) or 20 cm x 20 cm (18 cm x 18 cm active area) planar cells supplied by Ceramatec, Inc (Salt Lake City, Utah, USA). Multi-stack testing encompassed up to 720 10 cm x 10 cm cells and was conducted in a newly developed 15 kW Integrated Laboratory Scale (ILS) test facility. Gas composition, operating voltage, and operating temperature were varied during testing. The tests were heavily instrumented, and outlet gas compositions were monitored with a gas chromatograph. Results to date show the process to be a promising technique for large-scale hydrogen and syngas production. (author)

Stoots, C.M.; O' Brien, J.E.; Condie, K.G. [Idaho National Lab., Idaho Falls, Idaho (United States)], E-mail: Carl.stoots@inl.gov, James.obrien@inl.gov, Keith.condie@inl.gov; Hartvigsen, J.J. [Ceramatec Inc., Salt Lake City, Utah (United States)], E-mail: jjh@ceramatec.com

2009-07-01

319

Experimental investigation of AC interference on cathodically protected gas pipelines  

Energy Technology Data Exchange (ETDEWEB)

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

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

2004-07-01

320

Experimental investigation of waveforms in structures and materials  

Energy Technology Data Exchange (ETDEWEB)

New acoustic emission (AE) technology has recently been developed that is based on high fidelity measurement of waves in solids. University, government and industrial laboratories are now pursuing work in this area, and an overview of this work will be presented. In addition, waveforms from previous testing in several types of structures and materials will be presented in hopes of stimulating discussion on the type of theoretical work required to advance a practical, physics based AE technology. As an example, AE waveforms captured during the failure of an asymmetric graphite/epoxy laminate did not appear to resemble any published calculations. This is not surprising since the most recent body of work published on AE ended about 1985 and little interest in the subject has been exhibited since that time. This may be due to the fact that the AE technology followed a completely empirical path, thus providing little incentive for theoretical study. The new technology is already proving that the wave propagation approach (even though currently limited to plate theory) provides more information and far better discrimination between signal and noise.

Ziola, S.M.; Gorman, M.R. [Digital Wave Corporation, Englewood, CO (United States)

1995-12-31

 
 
 
 
321

EXPERIMENTAL INVESTIGATION & NUMERICAL ANALYSIS OF COMPOSITE LEAF SPRING  

Directory of Open Access Journals (Sweden)

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%.

K. K. JADHAO,; DR. R.S DALU

2011-01-01

322

Experimental investigation on an S-band relativistic klystron oscillator  

International Nuclear Information System (INIS)

The modulation mechanism and RF extraction of an S-band relativistic klystron oscillator were studied via experiment. It is found that intense relativistic electron beams(IREBs) can generate intense current modulation when the IREBs drift through three pillboxes with high coupling. After bunching in the downstream the modulated IREBs can excite high power micro- wave in the triaxial cavity. The RKO has properties of short oscillating time, compact geometry and high beam-wave conversion efficiency. Using a 1 MV/13 kA/40 ns electron beam and leading magnetic field of 0.9 T, 3.5 GW radiated power was extracted in 20 ns FWHM pulses at 2.86 GHz. The beam-wave transition efficiency is 29%, and the instantaneous bandwidth is 2%. The radiated power is 3.4 GW with the efficiency of 26% when repetitive pulse frequency of IREBs is 20 Hz. The experimental results agree well with the simulation ones. (authors)

2008-01-01

323

Theoretical and experimental investigation of magnetotransport in iron chalcogenides  

Directory of Open Access Journals (Sweden)

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.

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

2012-01-01

324

Experimental investigations of new passive devices for the SWR 1000  

International Nuclear Information System (INIS)

The innovative design concept of the SWR 1000 is based on some new passive devices in addition to the active systems. The aim is that even severe accidents can be handled using only passive systems assuming that all active systems could fail. The operation of passive systems is based only on basic laws of physics, such as gravity, heat transfer induced by temperature differences or the quality of swirl flow. These new passive devices were tested in different test facilities to prove their reliability and efficiency. All tests showed that the previously calculated efficiencies could be reached or even exceeded. So in some aspects better margins for the design could be proven than expected. Depending on the existing experimental results it seems to be possible to control all possible accidents only with passive safety systems. (author)

1998-01-01

325

Experimental investigations of new passive devices for the SWR 1000  

Energy Technology Data Exchange (ETDEWEB)

The innovative design concept of the SWR 1000 is based on some new passive devices in addition to the active systems. The aim is that even severe accidents can be handled using only passive systems assuming that all active systems could fail. The operation of passive systems is based only on basic laws of physics, such as gravity, heat transfer induced by temperature differences or the quality of swirl flow. These new passive devices were tested in different test facilities to prove their reliability and efficiency. All tests showed that the previously calculated efficiencies could be reached or even exceeded. So in some aspects better margins for the design could be proven than expected. Depending on the existing experimental results it seems to be possible to control all possible accidents only with passive safety systems. (author)

Meseth, Johann [Siemens-KWU, Berliner Str. 295, D-63010 Offenbach (Germany)

1998-07-01

326

Molten carbonate fuel cell: dynamic numerical modeling and experimental investigation  

Energy Technology Data Exchange (ETDEWEB)

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)

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

327

An experimental investigation on air impinging jets using visualisation methods  

Energy Technology Data Exchange (ETDEWEB)

Impinging jets are used in many applications for cooling or heating systems, for example cooling gas turbine blades. The jet impact on a surface and the interaction between the jet and the flow determine a complex flow field which leads to a high heat transfer coefficient. The study of this flow field is thus very important. An experimental flow visualisation study has been conducted using several techniques (smoke technique, oil and pigment and the thermotropic liquid crystal technique) to determine the flow pattern for a row and a system of jets impinging on a flat plate with subsonic velocity. Some secondary vortexes are shown, thus allowing the heat transfer coefficient distribution to be understood. (author)

Carcasci, C. [Florence Univ. (Italy). Dipartimento di Energetica S. Stecco (DEF)

1999-10-01

328

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

1988-01-01

329

Experimental Investigation of Hypersonic Flow and Plasma Aerodynamic Actuation Interaction  

Science.gov (United States)

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.

Sun, Quan; Cheng, Bangqin; Li, Yinghong; Cui, Wei; Yu, Yonggui; Jie, Junhun

2013-09-01

330

Experimental and modelling investigation of monolayer development with clustering.  

UK PubMed Central (United Kingdom)

Standard differential equation-based models of collective cell behaviour, such as the logistic growth model, invoke a mean-field assumption which is equivalent to assuming that individuals within the population interact with each other in proportion to the average population density. Implementing such assumptions implies that the dynamics of the system are unaffected by spatial structure, such as the formation of patches or clusters within the population. Recent theoretical developments have introduced a class of models, known as moment dynamics models, which aim to account for the dynamics of individuals, pairs of individuals, triplets of individuals, and so on. Such models enable us to describe the dynamics of populations with clustering, however, little progress has been made with regard to applying moment dynamics models to experimental data. Here, we report new experimental results describing the formation of a monolayer of cells using two different cell types: 3T3 fibroblast cells and MDA MB 231 breast cancer cells. Our analysis indicates that the 3T3 fibroblast cells are relatively motile and we observe that the 3T3 fibroblast monolayer forms without clustering. Alternatively, the MDA MB 231 cells are less motile and we observe that the MDA MB 231 monolayer formation is associated with significant clustering. We calibrate a moment dynamics model and a standard mean-field model to both data sets. Our results indicate that the mean-field and moment dynamics models provide similar descriptions of the 3T3 fibroblast monolayer formation whereas these two models give very different predictions for the MDA MD 231 monolayer formation. These outcomes indicate that standard mean-field models of collective cell behaviour are not always appropriate and that care ought to be exercised when implementing such a model.

Simpson MJ; Binder BJ; Haridas P; Wood BK; Treloar KK; McElwain DL; Baker RE

2013-05-01

331

Experimental and modelling investigation of monolayer development with clustering.  

Science.gov (United States)

Standard differential equation-based models of collective cell behaviour, such as the logistic growth model, invoke a mean-field assumption which is equivalent to assuming that individuals within the population interact with each other in proportion to the average population density. Implementing such assumptions implies that the dynamics of the system are unaffected by spatial structure, such as the formation of patches or clusters within the population. Recent theoretical developments have introduced a class of models, known as moment dynamics models, which aim to account for the dynamics of individuals, pairs of individuals, triplets of individuals, and so on. Such models enable us to describe the dynamics of populations with clustering, however, little progress has been made with regard to applying moment dynamics models to experimental data. Here, we report new experimental results describing the formation of a monolayer of cells using two different cell types: 3T3 fibroblast cells and MDA MB 231 breast cancer cells. Our analysis indicates that the 3T3 fibroblast cells are relatively motile and we observe that the 3T3 fibroblast monolayer forms without clustering. Alternatively, the MDA MB 231 cells are less motile and we observe that the MDA MB 231 monolayer formation is associated with significant clustering. We calibrate a moment dynamics model and a standard mean-field model to both data sets. Our results indicate that the mean-field and moment dynamics models provide similar descriptions of the 3T3 fibroblast monolayer formation whereas these two models give very different predictions for the MDA MD 231 monolayer formation. These outcomes indicate that standard mean-field models of collective cell behaviour are not always appropriate and that care ought to be exercised when implementing such a model. PMID:23584951

Simpson, Matthew J; Binder, Benjamin J; Haridas, Parvathi; Wood, Benjamin K; Treloar, Katrina K; McElwain, D L Sean; Baker, Ruth E

2013-04-13

332

Experimental investigation on air leakage characteristics of containments  

International Nuclear Information System (INIS)

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

2005-01-01

333

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

1990-01-01

334

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

Science.gov (United States)

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.

Vimal, Deepali

335

Experimental investigations of helium cryotrapping by argon frost  

International Nuclear Information System (INIS)

At the Karlsruhe Nuclear Research Centre (KfK) cryopumping techniques are being investigated by which the gaseous exhausts from the NET/ITER reactor can be pumped out during the burn-and dwell-times. Cryosorption and cryotrapping are techniques which are suitable for this task. It is the target of the investigations to test the techniques under NET/ITER conditions and to determine optimum design data for a prototype. They involve measurement of the pumping speed as a function of the gas composition, gas flow and loading condition of the pump surfaces. The following parameters are subjected to variations: Ar/He ratio, specific helium volume flow rate, cryosurface temperature, process gas composition, impurities in argon trapping gas, three-stage operation and two-stage operation. This paper is a description of the experiments on argon trapping techniques started in 1990. Eleven tests as well as the results derived from them are described

1991-10-04

336

Exploratory experimental investigations on posttensioned structural glass beams  

DEFF Research Database (Denmark)

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.

Louter, C.; Nielsen, Jens Henrik

337

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.

1999-01-01

338

Experimental Investigation of Turbulent Fluid Flow through a Rectangular Elbow  

Directory of Open Access Journals (Sweden)

Full Text Available 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 number of3.8

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

2010-01-01

339

EXPERIMENTAL INVESTIGATIONS OF BEARING CAPACITY FOR ECCENTRICALLY LOADED FOOTING  

Directory of Open Access Journals (Sweden)

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.

S. M. NAWGHARE; Dr. S. R. PATHAK; S. H. GAWANDE

2010-01-01

340

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.

1993-01-01

 
 
 
 
341

Laboratory investigation of the oxygen combustion process for heavy oil recovery  

Energy Technology Data Exchange (ETDEWEB)

The laboratory investigations were conducted using core material and produced oil from a typical Alberta heavy oil rservoir. The experiments established combustion characteristics using air and the combustion Thermal Drive (CTD) process for thermal oil recovery. Both the combustion and CTD tests indicated the oil's favorable response to thermal recovery. The results of laboratory studies using oxygen and oxygen with water injection have indicated that the enriched air process, as Ramey suggested almost thirty years ago, is not only viable as an oil recovery method, but the process is also highly desirable. 17 refs.

Moss, J.T.; Cady, G.V.

1982-01-01

342

Laboratory investigation of the oxygen combustion process of heavy oil recovery  

Energy Technology Data Exchange (ETDEWEB)

The laboratory investigations were conducted using core material and produced oil from a typical Alberta heavy oil reservoir. The experiments established combustion characteristics using air and the CTD process for thermal oil recovery. Both combustion and CTD tests indicated the oil's favorable response to thermal recovery. The results of laboratory studies using oxygen and oxygen with water injection have indicated that the enriched air process, as Ramey suggested almost thirty years ago, is not only viable as an oil recovery method, but the process is also highly desirable. 17 refs.

Moss, J.T.; Cady, G.V.

1982-01-01

343

Experimental Investigation of Slamming Loads on a Flat Plate  

Science.gov (United States)

Slamming loads on marine structures and vessels pose a hazard, with the potential for structural failure from the high momentary loads. With interest in higher speed vessels, exterior panels face tremendous impact loads from both wave impact and slamming. We have designed an experimental apparatus that can slam a variety of objects into a free surface at a range of deadrise angles and impact speeds. This system is instrumented with load cells to give us the force history of the impact, rather than the pressure on the face of the panel. Impact speeds over 5 m/s have been tested, with impact angles ranging from 1-25 degrees, using a foam core composite panel. We have documented the cushioning effect of trapped air between the plate and the free surface at small impact angles. We have also seen a correlation between the impact duration and the total force. The authors would like to thank the Office of Naval Research for their support of this experiment through award number N00014-06-1-0730. In addition, FJHH would like to acknowledge the support given by the European Commission through the Marie Curie IOF for actions for individuals (PIOF-GA-2008-219429).

Jeon, David; Huera-Huarte, Francisco; Fu, Matthew; Gharib, Mory

2010-11-01

344

Experimental Investigation of Using MR ! Fluids in Automobiles Suspension Systems  

Directory of Open Access Journals (Sweden)

Full Text Available In recent years, a flurry of interest has been shown for a relatively old technology called magnetorheologicalfluids, or MR fluids. Multiple types of devices have been designed to implement this versatile fluid,including linear dampers, clutches, work-piece fixtures, and polishing machines. The devices have been usedin automobiles, washing machines, bicycles, prosthetic limbs, and even smart structures. This paper focuseson another application of MR dampers, involving automobile suspension, and introduces using of MR dampersand automobile suspensions, and why the two would be a good combination. An experimental investigationis carried out to show the efficiency of using such fluids on suspension systems of the automobiles. The MRdampers provided a more stable ride than that of the OEM dampers. By reducing suspension displacement,settling time, and suspension oscillations, the MR dampers were able to reduce suspension geometry instability.It is found that the efficiency of damper used in this study increases by using MR fluids, and this efficiencyincreases as the current applied on the MR damper increase.

S.M. Fayyad

2010-01-01

345

Experimental Investigation of Moisture Driven Fracture in Solid Wood  

DEFF Research Database (Denmark)

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.

Larsen, Finn; Ormarsson, Sigurdur

2010-01-01

346

Experimental Investigations on Convective Losses in Solar Cavity Receivers  

Energy Technology Data Exchange (ETDEWEB)

An experimental study on the convective losses from a cylindrical downward facing cavity receiver is carried out with the aim of determining the stagnation and convective zone boundary. The study is conducted in an off-flux mode for inclination angles of 0 degree celsius (side facing horizontal cavity), 30 degree celsius, 45 degree celsius, 60 degree celsius and 9 (downward facing vertical cavity) for receiver fluid inlet temperatures of 50 degree celsius, 60 degree celsius and 75 degree celsius. The air, tube and fluid temperature profiles within the receiver are measured for above mentioned conditions. It is found that the total losses and the convective losses decrease with increasing angle (0 degree celsius to 90 degree celsius) as reported in literature. The stagnation and convective zones in the receiver for different operating conditions have been studied based on air temperature gradients at different locations. It has been found that for all the temperature and inclination cases tested here, the locations within the cavity having air temperature gradient less than 20 degree celsius/m fall in the stagnation zone while the locations having air temperature gradient greater than 20 degree celsius/m fall in the convective zone. (Author)

Prakash, M.; Balwant Kedare, S.; Kumar Nayak, J.

2006-07-01

347

Experimental investigation of some aspects affecting personnel dosimetry  

International Nuclear Information System (INIS)

The present study deals with various parameters affecting personnel dosimetry. Experimental results showed that the response of film badge and TL dosimeter depend on: (1) radiation energy,(2) beam direction, and (3) storage time. The calibration of the film badge and TLD badge with photon energy showed an error ±2%. The sensitivity of the dosimeters for photon energies showed a statistical fluctuation about ±7.5% for films and about ±4% for TLD. The error due to angular geometrical of the incident radiation is found to be ±6% for both film badge and TLD badge. Storage of irradiated film badge during 60 days showed negligible fading but TLD showed about ±3.2% fading during 60 days after irradiation. The error due to electronic un stability of the measuring devices is about ± 5% for both film and TLD badges. The error due to batch nonuniformity of dosimeters composition is found to be about ±5% for both film and TLD badges. The error due to batch nonuniformity of dosimeters composition is found to be about ±5% for both film and TLD badges. The error in calibrating radiation fields using lonix dosimeter is found to be ±3.5. The overall errors in the deduced personnel effective dose are approximately ±12.5% for film badge system and ±11.2% for TLD badge system. This error is acceptable for radiation protection purposes. 28 figs., 10 tabs., 91 refs

1997-01-01

348

Numerical and experimental investigations into Tailored Welded Blanks formability  

International Nuclear Information System (INIS)

[en] 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

2007-05-17

349

Laboratory open-quotes proof of principleclose quotes investigation for the acoustically enhanced remediation technology  

International Nuclear Information System (INIS)

Weiss Associates is conducting a three phase program investigating the systematics of using acoustic excitation fields (AEFs) to enhance the in-situ remediation of contaminated soil and ground water under both saturated and unsaturated conditions: Phase I - Laboratory Scale Parametric Investigation; Phase II - Technology Scaling Study; and Phase III - Large Scale Field Tests. Phase I, the subject of this paper, consisted primarily of a laboratory proof of principle investigation. The field deployment and engineering viability of acoustically enhanced remediation (AER) technology was also examined. Phase II is a technology scaling study addressing the scale up between laboratory size samples on the order of inches, and the data required for field scale testing, on the order of hundreds of feet. Phase III will consist of field scale testing at an non-industrialized, non-contaminated site and at a contaminated site to validate the technology. Summarized herein are the results of the Phase I open-quotes proof-of-principleclose quotes investigation, and recommendations for Phase H. A general overview of AER technology along with the plan for the Phase I investigation was presented.

1995-01-01

350

Experimental investigation on the preferential erosion of biochar  

Science.gov (United States)

The influence and effect of biochar on soil properties has been intensively investigated, particularly in the context of its potential to sequester carbon and mitigate the effects of anthropogenic climate change. One major question that remains unanswered concerns the erodibility and fate of biochar in the landscape. Since biochar has a lower bulk-density than soil, preferential erosion of biochar is most likely. However, until now, almost no actual data on the enrichment of biochar in in the eroded sediment or the net loss from fields exist. This important gap of knowledge could have profound economic implications for farmers committed to its use, since a high net annual loss of biochar by erosion could exceed any net annual economic gain. Most importantly, any positive gain for the environment largely depends on the amount of biochar that remains within the upper soil matrix. The overall objective of this study was to explicitly investigate the erodibility of biochar, if erosion events occur directly or soon after its application. I this way, the financial value of the eroded biochar and its cost-effectiveness, if applied to whole field scales, could be estimated. The test site is located near Viborg in north Jutland, Denmark. Biochar was applied to the soil surface of three plots on a recently cultivated sandy field at concentrations equivalent to 1.5-2.0 kg m-2 and manually incorporated within the till-zone. Three consecutive 30 min. erosion simulations were conducted on each plot using the 2.2 m-2 Portable Wind and Rainfall Simulator. The preliminary results of this study showed that a fair amount of biochar can be eroded from the fields within the first rainfall events after biochar application to the soil. In order to provide guidelines for its application and post-application management to reduce the erodibility and net discharge of biochar from fields, further investigations are needed.

Fister, Wolfgang; Heckrath, Goswin; Greenwood, Philip; Kuhn, Nikolaus J.

2013-04-01

351

Experimental Investigation of Two-color Polarization Spectroscopy in Rubidium  

Science.gov (United States)

We will report on our investigation of two-color polarization spectroscopy of room temperature rubidium atoms in a glass cell when one laser is tuned from the 5S to 5P transition at 780nm and a second laser is tuned from the 5P to 5D transition at 776nm. Both colors are derived from external cavity diode lasers and both common isotopes of rubidium have been studied. We will discuss the laser intensity dependence and the effect of applied magnetic fields on the observed line shapes. Finally, we will demonstrate how the spectra can be applied to frequency stabilization of the diode lasers.

Kulatunga, P.; Andrews, L. R.; Sukenik, C. I.; Busch, H. C.

2011-06-01

352

Optimal Cross-Validation Split Ratio: Experimental Investigation  

DEFF Research Database (Denmark)

Cross-validation is a common method for assessing the generalisation ability of a model in order to tune a regularisation parameter or otherhyper-parameters of a learning process. The use of cross-validation requires to set yet an additional parameter, the split rati. While a few texts haveinvestigated theoretically the asymptotic setting of this ratio, no consensus has emerged. In this contribution, we investigate the sensitivity and optimalsetting of the split ratio on a particular model, a non-parametric kernel estimator with adaptive metric.

Goutte, Cyril; Larsen, Jan

1998-01-01

353

Experimental investigation of ?-ray attenuation coefficients for granites  

International Nuclear Information System (INIS)

Highlights: ? Radiation shielding properties of granites have been investigated. ? This is done by measuring linear attenuation coefficients. ? Measurement was performed using 137Cs and 60Co sources. - Abstract: The linear attenuation coefficients of ?-rays for some granite samples have been measured at 662, 1773 and 1332 keV. The ?-rays have been obtained from 137Cs and 60Co sources respectively and the measurement have been performed using a gamma spectrometer which contains 3” × 3” NaI(Tl) detector connected to 16384 channel Multi-Channel-Analyser (MCA).

2012-01-01

354

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

International Nuclear Information System (INIS)

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

2008-01-01

355

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

International Nuclear Information System (INIS)

[en] 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)

2008-01-01

356

An experimental investigation of barite formation in seawater  

Science.gov (United States)

We report results from time-series decay and sequential leaching experiments of laboratory cultured and coastal plankton to elucidate the mechanisms controlling barite formation in seawater. Batch-cultured diatoms ( Stephanopyxis palmerina ) and coccolithophorids (Emiliania huxleyi) were let to decay in the dark for 8-10 weeks, suspended in aerated seawater. The development of barite crystals was monitored by Scanning Electron Microscopy (SEM). A similar experiment was conducted with plankton collected during the spring-bloom in Vineyard Sound (MA). In addition to SEM, suspended particles were sequentially leached for Ba (distilled water rinse; 10% (v/v) HNO3 rinse at room temperature; 30% (v/v) HCl at 80??C overnight; 50% (v/v) HNO3 at 80??C overnight) immediately after collection, and after 10-week decay in seawater, in seawater poisoned with HgCl2, and in seawater spiked with 135Ba. Both experiments showed an increase in the number of barite crystals during decay. The spring-bloom plankton had initially a large pool of labile Ba, soluble in distilled water and cold dilute HNO3 that was lost from the plankton after 10-week decay in both axenic and nonaxenic conditions. In contrast, Ba in the decayed plankton samples was predominantly in forms extracted by hot HCl and hot HNO3 acids, which were attributed to presence of barite Ba and refractory organic Ba respectively. The increase in barite crystal counts under a Scanning Electron Microscope (SEM), the increase in HCl extractable Ba relative to organic carbon, and the loss of a large fraction of Ba during plankton decay suggest that living plankton consists of a relatively large pool of labile Ba, which is rapidly released during plankton decomposition and acts as the main source of Ba for barite formation in supersaturated microenvironments. Since mass balance indicates that only a small proportion (2 to 4%) of the labile-Ba pool is converted to barite, the availability of microenvironments that could locally concentrate Ba released by plankton decay seems to be the main limiting factor in barite precipitation. ?? 2003 Elsevier Science Ltd.

Ganeshram, R. S.; Francois, R.; Commeau, J.; Brown-Leger, S. L.

2003-01-01

357

Laboratory analyses of micron-sized solid grains: Experimental techniques and recent results  

International Nuclear Information System (INIS)

Morphological and spectrophotometric investigations have been extensively applied in the past years to various kinds of micron and/or submicron-sized grains formed by materials which are candidate to be present in space. The samples are produced in the laboratory and then characterized in their physio-chemical properties. Some of the most recent results obtained on various kinds of carbonaceous materials are reported. Main attention is devoted to spectroscopic results in the VUV and IR wavelength ranges, where many of the analyzed samples show typical fingerprints which can be identified also in astrophysical and cometary materials. The laboratory methodologies used so far are also critically discussed in order to point out capabilities and present limitations, in the view of possible application to returned comet samples. Suggestions are given to develop new techniques which should overcome some of the problems faced in the manipulation and analysis of micron solid samples.

1989-01-01

358

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

CERN Document Server

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...

Shastri, A; Saraswati, P; Sunanda, K

2002-01-01

359

Experimental investigation on heat transport in gravel-sand materials.  

DEFF Research Database (Denmark)

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.

Maureschat, Gerald; Heller, Alfred

1997-01-01

360

Sensorimotor incongruence and body perception: an experimental investigation.  

UK PubMed Central (United Kingdom)

Objectives: Several studies have shown that mirrored arm or leg movements can induce altered body sensations. This includes the alleviation of chronic pain using congruent mirror feedback and the induction of abnormal sensation in healthy participants using incongruent mirror feedback. Prior research has identified neuronal and conceptual mechanisms of these phenomena. With the rising application of behavior-based methods for pain relief, a structured investigation of these reported effects seems necessary. Methods: We investigated a mirror setup that included congruent and incongruent hand and arm movements in 113 healthy participants and assessed the occurrence and intensity of unusual physical experiences such as pain, the sensation of missing or additional limbs, or changes in weight or temperature. A wooden surface instead of a mirror condition served as control. Results: As reported earlier, mirrored movements led to a variety of subjective reactions in both the congruent and incongruent movement condition, with the sensation of possessing a third limb being significantly more intense and frequent in the incongruent mirror condition. Reports of illusory pain were not more frequent during mirrored than during non-mirrored movements. Conclusion: These results suggest that, while all mirrored hand movements induce abnormal body perceptions, the experience of an extra limb is most pronounced in the incongruent mirror movement condition. The frequent sensation of having a third arm may be related to brain processes designed to integrate input from several senses in a meaningful manner. Painful sensations are not more frequent or intense when a mirror is present.

Foell J; Bekrater-Bodmann R; McCabe CS; Flor H

2013-01-01

 
 
 
 
361

Experimental investigation on alteration of bentonite by concrete pore fluids  

International Nuclear Information System (INIS)

As one of application examinations of bentonite for geological disposal, a fundamental study on long term change of its properties due to correlation to concrete was conducted. D. Savage, et.al. investigated on chemical change of bentonite by dividing dissolving reaction due to alkaline solution leached from intervals of the concrete and forming reaction of new minerals due to the dissolved substance. In order to elucidate the changing behavior of bentonite, examination due to the alkaline solution was also important, and then following investigations were conducted as a dissolving test due to the alkaline solution and a test of reaction product minerals in the alkaline solution. The changing behavior of bentonite was conducted by a heated acceleration test using a model solution of an interval solution of concrete. As a result, it was found that solubility of bentonite increased extremely with increase of pH over 11. A dissolving rate constant and activation energy were obtained at each pH. And, a mixed layer mineral, CSH, CAH, and so forth were found as reaction products, which increased with increase of pH and temperature. These results were useful for analysis of long term change of the bentonite, and suggested to necessity to use the concrete with pH as low as possible. (G.K.)

1998-01-01

362

Experimental Investigation of Drilling Fluid Performance as Nanoparticles  

Directory of Open Access Journals (Sweden)

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.

Jamal Nasser; Anna Jesil; Tariq Mohiuddin; Majid Al Ruqeshi; Geetha Devi; Shahjahan Mohataram

2013-01-01

363

An experimental investigation on the W-Cu composites  

Energy Technology Data Exchange (ETDEWEB)

Fabrication of tungsten-copper net-shapes has become an important issue in recent years due to their unique properties which make them suitable for a wide variety of applications. In this investigation, W-Cu composite powders containing 20 wt.% and 30 wt.% Cu were processed by powder metallurgy technique using two types of prepared powders, namely, Cu-coated tungsten and mixtures of elemental powders. The coating method of tungsten powders was carried out using electroless coating technique. The investigated powders were cold compacted and sintered in vacuum at two sintering temperatures, 1250 deg. C and 1400 deg. C. The results show that the Cu-coated compacts have higher relative green densities than those of admixed ones for each copper content and compaction pressure, which means that the coated powders have greater compressibility than the uncoated ones. The relative green density increases with increasing compaction pressure and copper content. After sintering, the composites fabricated from uncoated powders show inhomogeneous structure due to formation of large globules of copper and tungsten agglomerates, while the structure of coated tungsten composites reveals the existence of copper within the tungsten grains, forming uniform interconnected structure. In general, composites made from Cu-coated tungsten powders exhibited higher density, hardness, compression strength, and electrical conductivity than those of composites made from admixed elemental powders. However, coefficient of thermal expansion and electrical resistivity of Cu-coated composites showed lower values.

Ibrahim, A. [Faculty of Engineering, University of Helwan, Helwan 11792 (Egypt)], E-mail: asadek69@yahoo.com; Abdallah, M. [Faculty of Engineering, University of Helwan, Helwan 11792 (Egypt); Mostafa, S.F. [Central Metallurgical R and D Institute (CMRDI), Helwan 87 (Egypt); Hegazy, A. Abousree [King Abdulaziz University, Jeddah (Saudi Arabia)

2009-04-15

364

Experimental Investigation of Shrinkage of Nano Hair Reinforced Concrete  

Directory of Open Access Journals (Sweden)

Full Text Available Basically most of cement based mixtures are likely shrinking. Use of fibers is not a new idea in this case. Previously, there were some evidences that horse hair, straw and cotton fibers were used in mud and mortars in ancient times. Then, utilizing these fibers in concrete mixture may increase concrete workability and decrease shrinkage cracks. Due to nano cross-section of hair and its proper tensile strength this project investigates its application to reduce the shrinkage of concrete mixtures. For this purpose, human hair fibers were used in 0.4 and 0.8 and 1.2 weight percent and the length of the fibers in each case varied between 15 and 60 millimeter and the samples were made of dimensions of 40×40×160 millimeters. Results are shown as considerable amount of hair may reduce in the shrinkage in the hair reinforced concrete.

Yadollah Batebi; Alireza Mirzagoltabar; Seyed Mostafa Shabanian; Sara Fateri

2013-01-01

365

Experimental investigation of flash pyrolysis oil droplet combustion  

DEFF Research Database (Denmark)

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.

Ibrahim, Norazana; Jensen, Peter A.

2013-01-01

366

Experimental investigation of laminar turbulent intermittency in pipe flow  

CERN Multimedia

In shear flows turbulence first occurs in the form of localized structures (puffs/spots) surrounded by laminar fluid. We here investigate such spatially intermittent flows in a pipe experiment showing that turbulent puffs have a well defined interaction distance, which sets the minimum spacing of puffs as well as the maximum observable turbulent fraction. Two methodologies are employed here. Starting from a laminar flow puffs can be created by locally injecting a jet of fluid through the pipe wall. When the perturbation is applied periodically at low frequencies, as expected, a regular sequence of puffs is observed where the puff spacing is given by the ratio of the mean flow speed to the perturbation frequency. On the other hand, at large frequencies puffs are found to interact and annihilate each other. Varying the perturbation frequency an interaction distance can be determined. In the second set of experiments, the Reynolds number is reduced suddenly from fully developed turbulence to the intermittent reg...

Samanta, Devranjan; Hof, Bjoern

2010-01-01

367

Design criteria for ribbed channels: Experimental investigation and theoretical analysis  

Energy Technology Data Exchange (ETDEWEB)

The present study investigates heat transfer and pressure drop in flows through ribbed channel for application to turbine blade cooling. The experiments are conducted for different cross-sections, for Reynolds number from 20 to 60x10{sup 3}. Local heat transfer coefficients are obtained using a transient thermochromic liquid crystal (TLC) technique. Detailed knowledge of the local heat transfer coefficient is essential to analyze thermal stresses in turbine components, while the combined effect of heat transfer and pressure drop should be taken into account for a proper cooling system design. As a compromise has always to be found, a new design criteria to choose the most appropriate solution for typical turbomachinery parameters is inferred and shown. Entrance effects for ribbed channels are also studied, as the common hypothesis of fully developed flow is rarely satisfied in real engine geometries; relevant results are revealed. (author)

Facchini, Bruno; Innocenti, Luca; Surace, Marco [Dipartimento di Energetica Sergio Stecco Universita degli Studi di Firenze Via Santa Marta, 3 50139 Firenze (Italy)

2006-08-15

368

Experimental investigation of forced convection and desiccant integrated solar dryer  

Energy Technology Data Exchange (ETDEWEB)

An indirect forced convection and desiccant integrated solar dryer is designed and fabricated to investigate its performance under the hot and humid climatic conditions of Chennai, India. The system consists of a flat plate solar air collector, drying chamber and a desiccant unit. The desiccant unit is designed to hold 75kg of CaCl{sub 2}-based solid desiccant consisting of 60% bentonite, 10% calcium chloride, 20% vermiculite and 10% cement. Drying experiments have been performed for green peas at different air flow rate. The equilibrium moisture content M{sub e} is reached in 14h at an air flow rate of 0.03kg/m{sup 2}s. The system pickup efficiency, specific moisture extraction rate, dimensionless mass loss, mass shrinkage ratio and drying rate are discussed in this paper. (author)

Shanmugam, V. [Department of Mechanical Engineering, Sathyabama Deemed University, Chennai 600 119 (India); Natarajan, E. [Institute for Energy Studies, College of Engineering, Anna University, Chennai 600 025 (India)

2006-07-15

369

Experimental investigations into the physics of light emitting conjugated polymers  

CERN Document Server

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...

Whitelegg, S A

2001-01-01

370

Experimental Investigation of Aerosols Produced by Cosmic Rays  

DEFF Research Database (Denmark)

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.

Pedersen, Jens Olaf Pepke; Enghoff, Martin Andreas BØdker

371

The ideal flip-through impact: experimental and numerical investigation  

DEFF Research Database (Denmark)

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.

Bredmose, Henrik; Hunt-Raby, A.

2010-01-01

372

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.

1984-01-01

373

An Experimental Investigation on Structural Behaviour of Beam Column Joint  

Directory of Open Access Journals (Sweden)

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.

Naveen Hooda; Jyoti Narwal; Bhupinder Singh; Vivek Verma; Parveen Singh

2013-01-01

374

Experimental investigation of an alternating evaporator duty refrigerator/freezer  

Energy Technology Data Exchange (ETDEWEB)

A bistable solenoid valve has been used to build an alternating evaporator duty (AED) domestic refrigerator/freezer. This refrigerator has two vapor compression refrigeration loops that share a common compressor, condenser, and suction line heat exchanger. Each of the refrigeration loops has an expansion device and evaporator. One evaporator is located in the fresh food compartment and the other is located in the freezer compartment. The bistable solenoid valve directs the flow of the refrigerant through one loop at a time. Only one of the two compartments is cooled at any given time. With this configuration, the food compartment is cooled at a higher evaporator temperature than the freezer. Due to this, the energy efficiency of the refrigerator is improved by 8.5% over a conventional domestic refrigerator/freezer. Also, this cycle allows for completely independent temperature control of the freezer and fresh food compartments. There may be a penalty because this cycle does not allow for both loops to be simultaneously optimized. Isobutane was the only refrigerant used in this investigation.

Lavanis, M.; Haider, I.; Radermacher, R. [Univ. of Maryland, College Park, MD (United States)

1998-12-31

375

Experimental investigations on sodium plugging in narrow flow channels.  

Energy Technology Data Exchange (ETDEWEB)

A series of experiments was performed to investigate the potential for plugging of narrow flow channels of sodium by impurities (e.g., oxides). In the first phase of the experiments, clean sodium was circulated through the test sections simulating flow channels in a compact diffusion-bonded heat exchanger such as a printed circuit heat exchanger. The primary objective was to see if small channels whose cross sections are semicircles of 2, 4, and 6 mm in diameter are usable in liquid sodium applications where sodium purity is carefully controlled. It was concluded that the 2-mm channels, the smallest of the three, could be used in clean sodium systems at temperatures even as low as 100 to 110 C without plugging. In the second phase, sodium oxide was added to the loop, and the oxygen concentration in the liquid sodium was controlled by means of varying the cold-trap temperature. Intentional plugging was induced by creating a cold spot in the test sections, and the subsequent plugging behavior was observed. It was found that plugging in the 2-mm test section was initiated by lowering the cold spot temperature below the cold-trap temperature by 10 to 30 C. Unplugging of the plugged channels was accomplished by heating the affected test section.

Momozaki, Y.; Cho, D. H.; Sienicki, J. J.; Moisseytsev, A.; Nuclear Engineering Division

2010-08-01

376

Experimental Investigation of Lower Hybrid Wave Coupling in HT-7  

Science.gov (United States)

Experiments on lower hybrid wave (LHW) coupling were investigated in the HT-7 tokamak. Good coupling of LHW plasma has been demonstrated at different conditions in the HT-7 tokamak. Relevant results have proved that LHW-plasma coupling is affected by the phase difference between adjacent waveguides. Furthermore, the edge density around the grill and relevant coupling can be adjusted by changing the plasma line average density or the gap value between the LH grill and the last closed flux surfaces (LCFS). It is found that the coupling of LHWs becomes poor when the edge density around the LH grill is large enough in the HT-7 tokamak, and that coupling remains good with a proper edge density. With increasing LHW power, it is also found that the reflection coefficients (RCs) increase due to non-linear effects under conditions of low edge recycling, but can decrease under high edge recycling. The edge density depends mainly on the competition between the ponderomotive force (PMF) and the edge recycling intensity in the HT-7 tokamak.

Kong, Erhua; Ding, Bojiang; Zhang, Ting; Qin, Yongliang; Shan, Jiafang; Liu, Fukun; Li, Miaohui; Zhang, Lei; Wang, Mao; Liu, Liang; Xu, Handong; Jia, Hua; Wu, Zege; Feng, Jianqiang; Zhao, Lianmin; Yang, Yong

2013-10-01

377

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.

1989-01-01

378

Experimental investigations on sodium plugging in narrow flow channels  

International Nuclear Information System (INIS)

A series of experiments was performed to investigate the potential for plugging of narrow flow channels of sodium by impurities (e.g., oxides). In the first phase of the experiments, clean sodium was circulated through the test sections simulating flow channels in a compact diffusion-bonded heat exchanger such as a printed circuit heat exchanger. The primary objective was to see if small channels whose cross sections are semicircles of 2, 4, and 6 mm in diameter are usable in liquid sodium applications where sodium purity is carefully controlled. It was concluded that the 2-mm channels, the smallest of the three, could be used in clean sodium systems at temperatures even as low as 100 to 110 C without plugging. In the second phase, sodium oxide was added to the loop, and the oxygen concentration in the liquid sodium was controlled by means of varying the cold-trap temperature. Intentional plugging was induced by creating a cold spot in the test sections, and the subsequent plugging behavior was observed. It was found that plugging in the 2-mm test section was initiated by lowering the cold spot temperature below the cold-trap temperature by 10 to 30 C. Unplugging of the plugged channels was accomplished by heating the affected test section.

2010-08-01

379

Experimental investigation on CHF of tight lattice PWRs  

International Nuclear Information System (INIS)

[en] 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

1992-01-01

380

Experimental investigation of saturated polarization spectroscopy for quantatative concentration measurements  

International Nuclear Information System (INIS)

Polarization-spectroscopy (PS) line shapes and signal intensities are measured in well-characterized hydrogen-air flames operated over a wide range of equivalence ratios. We use both low (perturbative) and high (saturating) pump beam intensities in the counterpropagating pump-probe geometry. The effects of saturation on the line-center signal intensity and the resonance linewidth are investigated. The PS signal intensities are used to measure relative OH number densities in a series of near-adiabatic flames at equivalence ratios (?) ranging from 0.5 to 1.5. The use of saturating pump intensities minimizes the effect of pump beam absorption, providing more accurate number density measurements. When calibrated to the calculated OH concentration in the ?=0.6 flame, the saturated PS number density measurements probing the P1(2) transition are in excellent agreement with OH absorption measurements, equilibrium calculations of OH number density, and previous saturated degenerate four-wave mixing OH number density measurements. (c) 2000 Optical Society of America

2000-04-20

 
 
 
 
381

Experimental Investigation of Heat Transfer during Night-Time Ventilation  

DEFF Research Database (Denmark)

Night-time ventilation is seen as a promising approach for energy efficient cooling of buildings. However, uncertainties in the prediction of thermal comfort restrain architects and engineers from applying this technique. One parameter essentially affecting the performance of night-time ventilation is the heat transfer at the internal room surfaces. Increased convection is expected due to high air flow rates and the possibility of a cold air jet flowing along the ceiling, but the magnitude of these effects is hard to predict. In order to improve the predictability, heat transfer during night-time ventilation in case of mixing and displacement ventilation has been investigated in a full scale test room. The results show that for low air flow rates displacement ventilation is more efficient than mixing ventilation. For higher air flow rates the air jet flowing along the ceiling has a significant effect, and mixing ventilation becomes more efficient. A design chart to estimate the performance of night-time cooling during an early stage of building design is proposed.

Artmann, Nikolai; Jensen, Rasmus Lund

2010-01-01

382

Experimental investigation of natural convection induced by internal heat generation  

International Nuclear Information System (INIS)

Dilatation of a convection cell with respect to its Rayleigh number, one of the problems in internally heated convection, was quantitatively investigated by analyzing temperature field in a cell. The temperature field visualized by a thermo-chromic liquid crystal (TLC) expresses the cell dilatation. A calibration system was developed to convert the visualized photographs of the temperature field to the temperature field. A calibration curve correlating color information extracted from the photograph and temperature was determined from the approximately linear temperature distribution in the horizontal fluid layer using the hue method. Photos taken at various internal Rayleigh numbers were converted to the temperature field by the obtained curve. Extracting individual cells from a temperature field achieves a quantitative expression of the cell dilatation as the variation of the wavenumber of the cell with Rayleigh number increases. The temperature profile in a cell shows that high temperature areas appear at the apexes of the cell, largely different from the profile obtained by linear theory

2005-01-01

383

Experimental investigation of Ostwald ripening in an implanted system  

International Nuclear Information System (INIS)

[en] During ion beam synthesis of compounds in Si a specific redistribution process is responsible for the modification of the implant profile towards a uniform buried compound layer. This process is referred to as Ostwald ripening. Implantation of substoichiometric doses of reactive species leads to structures consisting of two precipitate bands. Investigations done by taking SEM-micrographs on beveled samples reveal that the structuring depends on the implantation conditions. Furthermore, splitting of the precipitate band located deeper in the substrate was observed and was seen as an effect of self-organisation. The development of the structures with time depends on the strength of the ripening process taking place parallel and perpendicular to the surface of the substrate. Using methods of spatial statistics the changes in the precipitate configuration according to the different ripening directions become obvious. Unfortunately, there exists no analytical model to describe the precipitation process in systems with inhomogeneous material distribution. Therefore, all the information retained from the experiments serve as an input for simulations to be done and will help to understand the contributions of different physical mechanisms. The results obtained in the course of the present study are described in terms of the formation of a buried oxide layer as a typical example of this kind

1999-01-03

384

Experimental investigation of the ribbon-array ablation process  

International Nuclear Information System (INIS)

Ablation processes of ribbon-array loads, as well as wire-array loads for comparison, were investigated on Qiangguang-1 accelerator. The ultraviolet framing images indicate that the ribbon-array loads have stable passages of currents, which produce axially uniform ablated plasma. The end-on x-ray framing camera observed the azimuthally modulated distribution of the early ablated ribbon-array plasma and the shrink process of the x-ray radiation region. Magnetic probes measured the total and precursor currents of ribbon-array and wire-array loads, and there exists no evident difference between the precursor currents of the two types of loads. The proportion of the precursor current to the total current is 15% to 20%, and the start time of the precursor current is about 25 ns later than that of the total current. The melting time of the load material is about 16 ns, when the inward drift velocity of the ablated plasma is taken to be 1.5 × 107 cm/s.

2013-01-01

385

Experimental investigations on superconducting niobium cavities at highest radiofrequency fields  

International Nuclear Information System (INIS)

In order to increase the maximum accelerating gradient in superconducting niobium cavities, electrolytic polishing was applied to 1.3 GHz single cell and nine-cell cavities. A facility for the electropolishing was set up in collaboration with CERN. Tests on single-cell cavities have shown that electropolishing increases the maximum accelerating gradient significantly as compared to the standard etching treatment. Preliminary results on high temperature heat treatments of electropolished cavities are shown. Electropolishing of nine-cell cavities was carried out in collaboration with KEK. One nine-cell cavity improved the accelerating gradient from 22 MV/m after standard etch to 32 MV/m after electropolishing. A low temperature 'in-situ' bakeout at 120 C for 48 hours was found to be necessary to reduce the degradation of the quality factor at accelerating fields above 25 MV/m. The detailed nature of this process is yet to be understood. Some models were investigated to describe this behaviour. (orig.)

2001-01-01

386

Experimental investigations on superconducting niobium cavities at highest radiofrequency fields  

Energy Technology Data Exchange (ETDEWEB)

In order to increase the maximum accelerating gradient in superconducting niobium cavities, electrolytic polishing was applied to 1.3 GHz single cell and nine-cell cavities. A facility for the electropolishing was set up in collaboration with CERN. Tests on single-cell cavities have shown that electropolishing increases the maximum accelerating gradient significantly as compared to the standard etching treatment. Preliminary results on high temperature heat treatments of electropolished cavities are shown. Electropolishing of nine-cell cavities was carried out in collaboration with KEK. One nine-cell cavity improved the accelerating gradient from 22 MV/m after standard etch to 32 MV/m after electropolishing. A low temperature 'in-situ' bakeout at 120 C for 48 hours was found to be necessary to reduce the degradation of the quality factor at accelerating fields above 25 MV/m. The detailed nature of this process is yet to be understood. Some models were investigated to describe this behaviour. (orig.)

Lilje, L.

2001-07-01

387

Experimental investigations on possibilities of chemical radiation protection  

International Nuclear Information System (INIS)

The radioprotective effect of the sulph-hydryl compounds N-acetyl-homocysteine-thiolactone and cysteine in combination with fructose (Reducdyn(R)) at various high radiation doses, different doses of the protective chemical and varying times of application before and after irradiation was investigated in animal experiments. Altogether, 540 mice were subjected in groups to whole body irradiation with 500, 1,000 and 2,000 R, doses of 0.1, 0.25, 0.5 and 1.0 ml Reducdyn(R) being injected intraperitoneally at each dose. In the case of animals irradiated with 1,000 R these different dosages of the protective chemical were given immediately before and 6, 12, 24, and 48 hours before and after the irradiation. The results showed that the effect of the protective substance decreased with increasing radiation dose, and was directly dependent on the dosage of the substance. A significant radioprotective effect could be demonstrated both with the prophylactic use of Reducdyn(R) 48 hours before irradiation and also 24 hours after exposure. The utilisation of this type of chemical radioprotective substance is possible when exploding nuclear weapons or in accidents in nuclear engineering establishments. (orig.)

1973-01-01

388

Experimental investigation of saturated polarization spectroscopy for quantatative concentration measurements  

Energy Technology Data Exchange (ETDEWEB)

Polarization-spectroscopy (PS) line shapes and signal intensities are measured in well-characterized hydrogen-air flames operated over a wide range of equivalence ratios. We use both low (perturbative) and high (saturating) pump beam intensities in the counterpropagating pump-probe geometry. The effects of saturation on the line-center signal intensity and the resonance linewidth are investigated. The PS signal intensities are used to measure relative OH number densities in a series of near-adiabatic flames at equivalence ratios ({phi}) ranging from 0.5 to 1.5. The use of saturating pump intensities minimizes the effect of pump beam absorption, providing more accurate number density measurements. When calibrated to the calculated OH concentration in the {phi}=0.6 flame, the saturated PS number density measurements probing the P{sub 1}(2) transition are in excellent agreement with OH absorption measurements, equilibrium calculations of OH number density, and previous saturated degenerate four-wave mixing OH number density measurements. (c) 2000 Optical Society of America.

Reichardt, Thomas A. [Department of Mechanical and Industrial Engineering, University of Illinois, 1206 West Green Street, Urbana, Illinois 61801 (United States); Giancola, William C. [Department of Mechanical and Industrial Engineering, University of Illinois, 1206 West Green Street, Urbana, Illinois 61801 (United States); Lucht, Robert P. [Department of Mechanical Engineering, Texas A and M University, College Station, Texas 77843-3123 (United States)

2000-04-20

389

Experimental investigation on transcritical heat transfer in He II  

International Nuclear Information System (INIS)

The propagation of plane second-sound waves has been investigated in a quadratic channel of 2.6x2.6 cm2 cross section and 8 cm length. The evolution of temperature, counterflow velocity, and superfluid vortex-line density has been measured. In agreement with current theories, the initial value of the vortex-line density remaining from the previous heat pulse increases induced by the counterflow velocity. If during the passage of the pulse enough vortex lines have been produced, the mutual friction force leads to a decrease of the counterflow velocity and hence of the heat flux. Then near the heater the energy is stored leading to a large rise in temperature instead of being transported by the second-sound wave. Further downstream, the mutual friction force is less significant, due to the decrease in counterflow velocity, resulting in the production of fewer superfluid vortex lines. Thus a (strongly damped) second-sound propagation takes place, superimposed by a diffusion process that causes the pulse to diverge during propagation. From a large number of temperature measurements, a criterion for the occurence of supercritical heat transport has been derived, taking into account bath temperature, pulse duration, heat flux and, in addition, the repetition rate, thus leading to a better approach to the measured values than current theories. (orig.).

1988-01-01

390

Histological changes caused by experimental Riedeliella graciliflora (Leg. Papilionoideae) poisoning in cattle and laboratory animals  

Directory of Open Access Journals (Sweden)

Full Text Available Tissues from cattle, mice, rats and guinea pigs experimentally intoxicated by Riedeliella graciliflora were studied histologically. Cattle lymph nodes, spleen, Peyer patches and peribronchial lymphoid tissues had diffuse necrosis of lymphocytes, mainly in the germinal centers of the follicles. This lesion was less severe in laboratory animals. All species had severe enteritis with infiltration of the lamina propria by mononuclear cells. Some cells in this infiltrate were necrotic. Degeneration and necrosis of the epithelial cells, mainly in the tip of the villi, and detachment of the epithelial lining from the lamina propria were also observed. In the liver the trabecular structure was disrupted and the hepatocytes had some degree of individual necrosis and degeneration. A tubular nephrosis was observed in the kidneys. Liver, lung, kidney, intestine and lymph nodes had different degrees of congestion. Those lesions are similar than those caused by Polygala klotzschii, a plant that contains 5-metoxi-podophyllotoxin.

Riet-Correa Franklin; Górniak Silvana L.; Haraguchi Mitsue; Dagli Maria Lúcia Z.

2001-01-01

391

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

DEFF Research Database (Denmark)

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.

Weinell, Claus Erik; Olsen, Kenneth N.

2003-01-01

392

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

International Nuclear Information System (INIS)

[en] 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

1989-01-01

393

Experimental investigation of in situ cleanable HEPA filter  

Energy Technology Data Exchange (ETDEWEB)

The Westinghouse Savannah River Company located at the Savannah River Site (SRS) in Aiken, South Carolina is currently testing the feasibility of developing an in situ cleanable high efficiency particulate air (HEPA) filter system. Sintered metal filters are being tested for regenerability or cleanability in simulated conditions found in a high level waste (HLW) tank ventilation system. The filters are being challenged using materials found in HLW tanks. HLW simulated salt, HLW simulated sludge and South Carolina road dust. Various cleaning solutions have been used to clean the filters in situ. The tanks are equipped with a ventilation system to maintain the tank contents at negative pressure to prevent the release of radioactive material to the environment. This system is equipped with conventional disposable glass-fiber HEPA filter cartridges. Removal and disposal of these filters is not only costly, but subjects site personnel to radiation exposure and possible contamination. A test apparatus was designed to simulate the ventilation system of a HLW tank with an in situ cleaning system. Test results indicate that the Mott sintered metal HEPA filter is suitable as an in situ cleanable or regenerable HEPA filter. Data indicates that high humidity or water did not effect the filter performance and the sintered metal HEPA filter was easily cleaned numerous times back to new filter performance by an in situ spray system. The test apparatus allows the cleaning of the soiled HEPA filters to be accomplished without removing the filters from process. This innovative system would eliminate personnel radiation exposure associated with removal of contaminated filters and the high costs of filter replacement and disposal. The results of these investigations indicate that an in situ cleanable HEPA filter system for radioactive and commercial use could be developed and manufactured.

Adamson, D.J.

1999-07-01

394

EXPERIMENTAL INVESTIGATION OF 2kW HIGH PRESSURE GASIFIER  

Directory of Open Access Journals (Sweden)

Full Text Available In a gasifier, the main attractive factors are the design and the operation. An optimized gasification process produces a considerably clean gas without additional energy. So a double walled gasifier combining the features of a closed top and an open top gasifier was developed and the performance behavior was investigated at different operating pressures. The gasifier has a total height of 1500mm, made of stainless steel with internal diameter of 196mm and thickness of 4.2mm. A conical section of height 300mm is provided at the bottom of the gasifier. The gasifier was tested using wood chips of size approximately 12.5mm x 12.5mm x 12.5mm. A total feed of 7-8 kg of wood was fed into the system and an airflow rate of 110 lpm was supplied by a compressor and the gasifier was tested at different operating pressures. The main variables namely oxidation zonetemperature, combustible contents ( H2 ,CO & CH4), calorific value, gas production rate and cold gas efficiency was studied .The percentage of total combustible components (H2, CO, CH4) was found to vary between 21.46% - 34.6% and their average composition was H2 =20.36% - 23.782%, CO = 9.658% – 11.82%, CH4 =0.872% – 1.432 %, N2 = 47.42% – 52.36%, CO2 = 12.086%-18.154%. The calorific value of the gas was found to vary between 3.975 MJ/m3 - 4.532 MJ/m3 while the cold gas efficiency varied between 68.39% - 91.389%

C.MOHANRAJ; J.EZHIL

2013-01-01

395

An experimental investigation on DI diesel engine with hydrogen fuel  

Energy Technology Data Exchange (ETDEWEB)

The internal combustion engines have already become an indispensable and integral part of our present day life style, particularly in the transportation and agricultural sectors [Nagalingam B. Properties of hydrogen. In: Proceedings of the summer school of hydrogen energy, IIT Madras, 1984]. Unfortunately the survival of these engines has, of late, been threatened due to the problems of fuel crisis and environmental pollution. Therefore, to sustain the present growth rate of civilization, a nondepletable, clean fuel must be expeditiously sought. Hydrogen exactly caters to the specified needs. Hydrogen, even though ''renewable'' and ''clean burning'', does give rise to some undesirable combustion problems in an engine operation, such as backfire, pre-ignition, knocking and rapid rate of pressure rise [Srinivasa Rao P. Utilization of hydrogen in a dual fueled engine. In: Proceedings of the summer school of hydrogen energy, IIT Madras, 1984; Siebers DL. Hydrogen combustion under diesel engine conditions. Hydrogen Energy 1998;23:363-71]. The present investigation compares the performance and emission characteristics of a DI diesel engine with gaseous hydrogen as a fuel inducted by means of carburation technique and timed port injection technique (TPI) along with diesel as a source of ignition [Swain N, Design and testing of dedicated hydrogen-fueled engine. SAE 961077, 1996]. In the present study the specific energy consumption, NO{sub x} emission and the exhaust gas temperature increased by 6%, 8% and 14%, respectively, and brake thermal efficiency and smoke level reduced by 5% and 8%, respectively, using carburation technique compared to baseline diesel. But in the TPI technique, the specific energy consumption, exhaust gas temperature and smoke level reduced by 15%, 45% and 18%, respectively. The brake thermal efficiency and NO{sub x} increased by 17% and 34%, respectively, compared to baseline diesel. The emissions such as HC, CO, and CO{sub 2} is very low in both carburation and TPI techniques compared baseline diesel. (author)

Saravanan, N.; Nagarajan, G.; Narayanasamy, S. [Internal Combustion Engineering Division, Department of Mechanical Engineering, College of Engineering, Guindy, Anna University, Chennai 600 025 (India)

2008-03-15

396

Experimental investigation of polymer flow in injection mould  

Directory of Open Access Journals (Sweden)

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 proc