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1

Conducting social science laboratory experiments on the world wide web  

Microsoft Academic Search

Researchers in the behavioral and social sciences, particularly psychology, are beginning to conduct laboratory experiments on the World Wide Web. The Web venue offers conveniences that are apparent to market researchers and academic investigators, who have used the Web extensively for survey research. Like traditional experimental researchers. Web experimenters must assure the reliability and inferential validity of their experiments to

Alison I. Piper

1998-01-01

2

Results from long conduction time plasma opening switch experiments at Sandia National Laboratories.  

National Technical Information Service (NTIS)

Sandia National Laboratories is conducting research on Plasma Opening Switches (POS) with input current fluxing times of 200--250 nanoseconds. The opening switches that have been studied at Sandia employ auxiliary magnetic fields to control the switch pla...

M. E. Savage W. W. Simpson M. A. Usher

1993-01-01

3

Conductance quantization: A laboratory experiment in a senior-level nanoscale science and technology course  

NASA Astrophysics Data System (ADS)

We describe a simple, inexpensive, and robust undergraduate lab experiment that demonstrates the emergence of quantized conductance as a macroscopic gold wire is broken and unbroken. The experiment utilizes a mechanically controlled break junction and demonstrates how conductance quantization can be used to understand the importance of quantum mechanics at the nanoscale. Such an experiment can be integrated into the curriculum of a course on nanoscale science or contemporary physics at the junior and senior levels.

Tolley, R.; Silvidi, A.; Little, C.; Eid, K. F.

2013-01-01

4

A Laboratory Experiment, Based on the Maillard Reaction, Conducted as a Project in Introductory Statistics  

ERIC Educational Resources Information Center

A simple laboratory experiment, based on the Maillard reaction, served as a project in Introductory Statistics for undergraduates in Food Science and Technology. By using the principles of randomization and replication and reflecting on the sources of variation in the experimental data, students reinforced the statistical concepts and techniques…

Kravchuk, Olena; Elliott, Antony; Bhandari, Bhesh

2005-01-01

5

Portable Conduction Velocity Experiments Using Earthworms for the College and High School Neuroscience Teaching Laboratory  

ERIC Educational Resources Information Center

The earthworm is ideal for studying action potential conduction velocity in a classroom setting, as its simple linear anatomy allows easy axon length measurements and the worm's sparse coding allows single action potentials to be easily identified. The earthworm has two giant fiber systems (lateral and medial) with different conduction…

Shannon, Kyle M.; Gage, Gregory J.; Jankovic, Aleksandra; Wilson, W. Jeffrey; Marzullo, Timothy C.

2014-01-01

6

Laboratory Determination of Hydraulic Conductivity  

NSDL National Science Digital Library

From D.B. McWhorterand D. K. Sunda's 1977 Ground-Water Hydrology and Hydraulics, this two page excerpt outlines and details Laboratory Determination of Hydraulic Conductivity. Here, visitors will find illustrations and formula to understand the concept.

2008-02-07

7

An Organoleptic Laboratory Experiment  

NASA Astrophysics Data System (ADS)

Flavorings in foods and fragrances in personal care products is a topic often discussed in chemistry classes designed for the general education of non-science majors. A laboratory experiment has been designed to accompany the lecture topic. Compounds in ten different classes of organic molecules that are used in the fragrance and food industry are provided to students. Students whiff the vapors of each compound and describe the organoleptic properties using a set of terms utilized in the fragrance and food industry. A set of questions guides students to an understanding of the relationship between structure of molecules and smell. Students are permitted to create their own fragrance based on the results of the experiment. Student response has been favorable. The experiment rectifies misconceptions students have about structure and odor, and gives positive reinforcement to the lecture material.

Risley, John M.

1996-12-01

8

Conducting Miller-Urey Experiments  

NASA Technical Reports Server (NTRS)

In 1953, Stanley Miller reported the production of biomolecules from simple gaseous starting materials, using apparatus constructed to simulate the primordial Earth's atmosphere-ocean system. Miller introduced 200 ml of water, 100 mmHg of H2, 200mmHg of CH4, and 200mmHg of NH3 into the apparatus, then subjected this mixture, under reflux, to an electric discharge for a week, while the water was simultaneously heated. The purpose of this manuscript is to provide the reader with a general experimental protocol that can be used to conduct a Miller-Urey type spark discharge experiment, using a simplified 3 L reaction flask. Since the experiment involves exposing inflammable gases to a high voltage discharge, it is worth highlighting important steps that reduce the risk of explosion. The general procedures described in this work can be extrapolated to design and conduct a wide variety of electric discharge experiments simulating primitive planetary environments.

Parker, Eric Thomas; Cleaves, Henderson James; Burton, Aaron S.; Glavin, Daniel P.; Dworkin, Jason; Zhou, Manshui; Bada, Jeffrey L.; Fernandez, Facundo M.

2014-01-01

9

Conducting miller-urey experiments.  

PubMed

In 1953, Stanley Miller reported the production of biomolecules from simple gaseous starting materials, using an apparatus constructed to simulate the primordial Earth's atmosphere-ocean system. Miller introduced 200 ml of water, 100 mmHg of H2, 200 mmHg of CH4, and 200 mmHg of NH3 into the apparatus, then subjected this mixture, under reflux, to an electric discharge for a week, while the water was simultaneously heated. The purpose of this manuscript is to provide the reader with a general experimental protocol that can be used to conduct a Miller-Urey type spark discharge experiment, using a simplified 3 L reaction flask. Since the experiment involves exposing inflammable gases to a high voltage electric discharge, it is worth highlighting important steps that reduce the risk of explosion. The general procedures described in this work can be extrapolated to design and conduct a wide variety of electric discharge experiments simulating primitive planetary environments. PMID:24473135

Parker, Eric T; Cleaves, James H; Burton, Aaron S; Glavin, Daniel P; Dworkin, Jason P; Zhou, Manshui; Bada, Jeffrey L; Fernández, Facundo M

2014-01-01

10

Laboratory magnetic reconnection experiments  

NASA Astrophysics Data System (ADS)

Since 1985, we have been investigating various physics and applications of magnetic recon-nection using TS-3 (1985-), TS-4 (2000-) and UTST (2006-) torus plasma merging devices. Recently, we found two fast reconnection mechanisms: 3-D reconnection and plasmoid (current-sheet) ejection in addition to the anomalous resistivity of current sheet reported in 1995. The 3-D local deformation of current sheet was observed when two tokamak plasmas with low guide-field were over-compressed by external coils. Note that global mode amplitudes of merg-ing toroids were maintained low during the reconnection. The toroidal asymmetry grew locally around the current sheet only during the reconnection and disappeared right after the recon-nection. This 3-D effect was emphasized by high plasma inflow and low guide-field. The 3-D deformation was observed to increase the plasma mass ejection from the current sheet. The local compression of current sheet thickness shorter than the ion gyro-radius triggered its anomalous resistivity, causing significant increase in the reconnection speed. The intermittent reconnections by current sheet/ plasmoid ejection was observed when two tokamaks with high guide-field were over-compressed by the external coils. Under high guide-field, the sheet resis-tivity was almost classical due to the sheet thickness larger than ion gyroradius. Large inflow flux and low current-sheet dissipation caused flux pileup inside the current sheet, indicating rapid growth of the current sheet. When the flux pileup exceeded a critical limit, the sheet was ejected mechanically from the squeezed X-point area. The reconnection (outflow) speed was slow during the flux pileup and was fast during the ejection. Due to the combination of pileup and ejection the intermittent reconnection increased the averaged reconnection speed. These fast reconnections enable us to maximize the heating power of merging tokamaks, leading us to a new ultra-high-beta spherical tokamak (ST) experiment UTST by use of high power heating of magnetic reconnection/ merging and 0.7MW neutral beam injection (NBI).

Ono, Yasushi

11

IN-SERVICE HYDRAULIC CONDUCTIVITY OF GCLS IN LANDFILL COVERS - LABORATORY AND FIELD STUDIES  

EPA Science Inventory

Laboratory experiments using multi-species inorganic solutions (containing calcium and sodium) were conducted on specimens of a new geosynthetic clay liner (GCL) containing sodium bentonite to determine how cation exchange and desiccation affected the hydraulic conductivity. Calc...

12

Laboratory experiments in atmospheric optics.  

PubMed

Old and new laboratory experiments on atmospheric optics with a focus on mirages, rainbows, and halos are presented. Some qualitative demonstrations serve primarily didactical purposes, e.g., by proving the existence of curved light rays in media with a gradient of the index of refraction, by directly visualizing the minimum-deviation curve for rainbow paths in water droplets, or by helping to elucidate the ray classes in hexagons that contribute to a specific halo. In addition, quantitative experiments allow a direct comparison of angular positions and intensities with analytical computations or Monte Carlo simulations of light scattering from small water droplets or ice hexagons. In particular, the latter can help us to understand complex halo phenomena. PMID:19399049

Vollmer, M; Tammer, R

1999-08-16

13

Laboratory experiments in atmospheric optics.  

PubMed

Old and new laboratory experiments on atmospheric optics with a focus on mirages, rainbows, and halos are presented. Some qualitative demonstrations serve primarily didactical purposes, e.g., by proving the existence of curved light rays in media with a gradient of the index of refraction, by directly visualizing the minimum-deviation curve for rainbow paths in water droplets, or by helping to elucidate the ray classes in hexagons that contribute to a specific halo. In addition, quantitative experiments allow a direct comparison of angular positions and intensities with analytical computations or Monte Carlo simulations of light scattering from small water droplets or ice hexagons. In particular, the latter can help us to understand complex halo phenomena. PMID:18268748

Vollmer, M; Tammer, R

1998-03-20

14

Laboratory Electrical Conductivity Measurement of Mantle Minerals  

Microsoft Academic Search

Electrical conductivity structures of the Earth’s mantle estimated from the magnetotelluric and geomagnetic deep sounding\\u000a methods generally show increase of conductivity from 10?4–10?2 to 100 S\\/m with increasing depth to the top of the lower mantle. Although conductivity does not vary significantly in the lower\\u000a mantle, the possible existence of a highly conductive layer has been proposed at the base of

Takashi Yoshino

2010-01-01

15

Customized Laboratory Experience in Physical Chemistry  

ERIC Educational Resources Information Center

A new physical chemistry laboratory experience has been designed for upper-level undergraduate chemistry majors. Students customize the first 10 weeks of their laboratory experience by choosing their own set of experiments (from a manual of choices) and setting their own laboratory schedule. There are several topics presented in the accompanying…

Castle, Karen J.; Rink, Stephanie M.

2010-01-01

16

Laboratory annoyance and skin conductance responses to some natural sounds  

NASA Astrophysics Data System (ADS)

The influences of spectral properties of sounds on annoyance and electrodermal activity reactions have been studied. In two laboratory experiments, subjects were exposed to some natural sounds in semi-anechoic conditions. Skin conductance and annoyance reactions were determined. The results suggest that electrodermal activity increases when the A-weighted equivalent sound pressure level exceeds 70 dB(A). It is concluded that the width of the spectrum is relevant, and that the greater the fundamental frequency of the harmonic spectrum the more annoying the sound.

Björk, E. A.

1986-09-01

17

Two LANL laboratory astrophysics experiments  

NASA Astrophysics Data System (ADS)

Two laboratory experiments are described that have been built at Los Alamos (LANL) to gain access to a wide range of fundamental plasma physics issues germane to astro, space, and fusion plasmas. The over arching theme is magnetized plasma dynamics which includes significant currents, MHD forces and instabilities, magnetic field creation and annihilation, sheared flows and shocks. The Relaxation Scaling Experiment (RSX) creates current sheets and flux ropes that exhibit fully 3D dynamics, and can kink, bounce, merge and reconnect, shred, and reform in complicated ways. Recent movies from a large data set describe the 3D magnetic structure of a driven and dissipative single flux rope that spontaneously self saturates a kink instability. Examples of a coherent shear flow dynamo driven by colliding flux ropes will also be shown.The Magnetized Shock Experiment (MSX) uses Field reversed configuration (FRC) experimental hardware that forms and ejects FRCs at 150km/sec. This is sufficient to drive a collision less magnetized shock when stagnated into a mirror stopping field region with Alfven Mach number MA=3 so that super critical shocks can be studied. We are building a plasmoid accelerator to drive Mach numbers MA >> 3 to access solar wind and more exotic astrophysical regimes. Unique features of this experiment include access to parallel, oblique and perpendicular shocks, shock region much larger than ion gyro radii and ion inertial length, room for turbulence, and large magnetic and fluid Reynolds numbers.*DOE Office of Fusion Energy Sciences under LANS contract DE-AC52-06NA25396, NASA Geospace NNHIOA044I, Basic, Center for Magnetic Self Organization

Intrator, Thomas; Weber, Thomas; Feng, Yan; Hutchinson, Trevor; Dunn, John; Akcay, Cihan

2014-06-01

18

Laboratory experiments of freshwater discharge into the ocean  

Microsoft Academic Search

Laboratory experiments have been conducted to explore the evolution of freshwater discharged on top of salt water in a rotating table. These experiments are motivated by the need to develop fundamental understanding of the dynamics of glacial melt water released into the ocean. They have been performed on a turntable with 2-m diameter and flat bottom in the GFD Laboratory

Olivier Marchal; John Whitehead; Anders Jensen

2010-01-01

19

Some Experiments with Biological Applications for the Elementary Laboratory  

ERIC Educational Resources Information Center

Summarizes physics laboratory experiments with applications in the biological sciences. Includes the following topics: mechanics of the human arm, fluid flow in tubes, physics of learning, the electrocardiograph, nerve impulse conduction, and corrective lenses for eye defects. (Author/MLH)

Kammer, D. W.; Williams, J. A.

1975-01-01

20

Rotating, hydromagnetic laboratory experiment modelling planetary cores  

NASA Astrophysics Data System (ADS)

This dissertation describes a series of laboratory experiments motivated by planetary cores and the dynamo effect, the mechanism by which the flow of an electrically conductive fluid can give rise to a spontaneous magnetic field. Our experimental apparatus, meant to be a laboratory model of Earth's core, contains liquid sodium between an inner, solid sphere and an outer, spherical shell. The fluid is driven by the differential rotation of these two boundaries, each of which is connected to a motor. Applying an axial, DC magnetic field, we use a collection of Hall probes to measure the magnetic induction that results from interactions between the applied field and the flowing, conductive fluid. We have observed and identified inertial modes, which are bulk oscillations of the fluid restored by the Coriolis force. Over-reflection at a shear layer is one mechanism capable of exciting such modes, and we have developed predictions of both onset boundaries and mode selection from over-reflection theory which are consistent with our observations. Also, motivated by previous experimental devices that used ferromagnetic boundaries to achieve dynamo action, we have studied the effects of a soft iron (ferromagnetic) inner sphere on our apparatus, again finding inertial waves. We also find that all behaviors are more broadband and generally more nonlinear in the presence of a ferromagnetic boundary. Our results with a soft iron inner sphere have implications for other hydromagnetic experiments with ferromagnetic boundaries, and are appropriate for comparison to numerical simulations as well. From our observations we conclude that inertial modes almost certainly occur in planetary cores and will occur in future rotating experiments. In fact, the predominance of inertial modes in our experiments and in other recent work leads to a new paradigm for rotating turbulence, starkly different from turbulence theories based on assumptions of isotropy and homogeneity, starting instead with inertial modes, which are the linear eigenmodes of any rapidly rotating fluid.

Kelley, Douglas H.

2009-10-01

21

Fluid Flow Experiment for Undergraduate Laboratory.  

ERIC Educational Resources Information Center

The undergraduate fluid mechanics laboratory at Clarkson University consists of three experiments: mixing; drag measurements; and fluid flow and pressure drop measurements. The latter experiment is described, considering equipment needed, procedures used, and typical results obtained. (JN)

Vilimpochapornkul, Viroj; Obot, Nsima T.

1986-01-01

22

Laboratory Experience for Teaching Sensory Physiology  

ERIC Educational Resources Information Center

The major challenge in laboratory teaching is the application of abstract concepts in simple and direct practical lessons. However, students rarely have the opportunity to participate in a laboratory that combines practical learning with a realistic research experience. In the Bioengineering Department, we started an experiential laboratory…

Albarracin, Ana L.; Farfan, Fernando D.; Felice, Carmelo J.

2009-01-01

23

An experiment on experiments in a senior laboratory  

NSDL National Science Digital Library

In a senior modern physics laboratory, "design" or "ingenuity" experiments were introduced to acquaint students with methods of doing complete experiments. The former deals with proposed long term studies while the latter deals with apparatus and short term actual studies.

Finegold, Leonard; Hartley, Charles L.

2006-05-17

24

Modeling a Thermal Seepage Laboratory Experiment  

SciTech Connect

A thermal seepage model has been developed to evaluate the potential for seepage into the waste emplacement drifts at the proposed high-level radioactive materials repository at Yucca Mountain when the rock is at elevated temperature. The coupled-process-model results show that no seepage occurs as long as the temperature at the drift wall is above boiling. This important result has been incorporated into the Total System Performance Assessment of Yucca Mountain. We have applied the same conceptual model to a laboratory heater experiment conducted by the Center for Nuclear Waste Regulatory Analyses. This experiment involves a fractured-porous rock system, composed of concrete slabs, heated by an electric heater placed in a 0.15 m diameter ''drift''. A substantial volume of water was released above the boiling zone over a time period of 135 days, giving rise to vaporization around the heat source. In this study, two basic conceptual models, similar to the thermal seepage models used in the Yucca Mountain Project, a dual-permeability model and an active-fracture model, are set up to predict evolution of temperature and saturation at the ''drift'' crown, and thereby to estimate potential for thermal seepage. Preliminary results from the model show good agreement with temperature profiles as well as with the potential seepage indicated in the lab experiments. These results build confidence in the thermal seepage models used in the Yucca Mountain Project. Different approaches are considered in our conceptual model to implement fracture-matrix interaction. Sensitivity analyses of fracture properties are conducted to help evaluation of uncertainty.

Y. Zhang; J. Birkholzer

2004-07-30

25

Experiments On Transparent Conductive Films For Spacecraft  

NASA Technical Reports Server (NTRS)

Report describes experiments on thin, transparent, electrically conductive films made, variously, of indium tin oxide covered by magnesium fluoride (ITO/MgF2), aluminum-doped zinc oxide (AZO), or pure zinc oxide (ZnO). Films are candidates for application to such spacecraft components, including various optoelectronic devices and window surfaces that must be protected against buildup of static electric charge. On Earth, such films useful on heat mirrors, optoelectronic devices, gas sensors, and automotive and aircraft windows.

Perez-Davis, Marla E.; Rutledge, Sharon K.; De Groh, Kim K.; Hung, Ching-Cheh; Malave-Sanabria, Tania; Hambourger, Paul; Roig, David

1995-01-01

26

A Kinetic Experiment for the Biochemistry Laboratory.  

ERIC Educational Resources Information Center

Discusses the use of specific reactions of metabolic pathways to make measurements in the laboratory. Describes an adaptation of an experiment used in undergraduate biochemistry laboratories involving the induction of an enzyme in E. coli, as well as its partial purification and characterization. (TW)

Palmer, Richard E.

1986-01-01

27

CONDUCTIVITY PROFILE RATE OF CHANGE FROM FIELD AND LABORATORY DATA WITHIN BIODEGRADING PETROLEUM HYDROCARBON  

EPA Science Inventory

We present the results of long term (500 days) measurements of the bulk conductivity in a field and laboratory experiment. Our objective was to determine the rate of change in bulk conductivity and whether this rate of change correlated with the petroleum hydrocarbon degradation...

28

LABORATORY EXPERIMENTS USING A PULSED NEUTRON SOURCE  

Microsoft Academic Search

Laboratory experiments using pulsed neutron techniques are valuable for ; giving physical interpretation of reactor theory. Three experiments illustrate ; different pulsed neutron measurements. In one case diffusion properties of a ; sample are measured by varying the geometry of the sample. In another the ; absorption cross section of a solute is measured by varying the sample without ;

R. B. Mesler; H. G. OBrien; D. Freed

1962-01-01

29

Kohlrausch Heat Conductivity Apparatus for Intermediate or Advanced Laboratory  

ERIC Educational Resources Information Center

Describes student experiment in measuring heat conductivity according to Kohlrausch's method. Theory, apparatus design, and experimental procedure is outlined. Results for copper are consistent to within 2 percent. (LC)

Jensen, H. G.

1970-01-01

30

Plume Electrification: Laboratory and Numerical Experiments  

NASA Astrophysics Data System (ADS)

The spectacular lightning strokes observed during eruptions testify to the enormous potentials that can be generated within plumes. Related to the charging of individual ash particles, large electric fields and volcanic lightning have been observed at Eyjafjallajokull, Redoubt, and Chaiten, among other volcanoes. A number of mechanisms have been proposed for plume electrification, including triboelectric charging, charging from the brittle failure of rock, and charging due to phase change as material is carried aloft. While the overall electrification of the plume likely results from a combination of these processes, in the following work we focus on triboelectric charging—how a plume charges as particles collide with each other. To explore the role of triboelectric effects in plume charging we have conducted a number of small scale laboratory experiments similar to those designed by Forward et al (2009). Succinctly, the experiments consist of fluidizing an ash bed with nitrogen and monitoring the resulting currents induced by the moving particles. It is important to note that the reaction chamber only allows particle-particle interactions. The entire experimental setup is enclosed in a vacuum chamber, allowing us to carefully control the environment during experiments. Runs were carried out for different ash compositions, and driving pressures. We particularly focused on natural grain size distributions of ash and on quantifying not only the net charge but also the charging rate. Furthermore, we report on our progress to incorporate the collected data, namely charging rates, into a large eularian-eularian-lagrangian multiphase eruption dynamic model. Finally, to validate these results, we present our plans to deploy a large wireless sensor network of electrometers and magnetometers around active volcanoes to directly map the overhead E- and M-fields as an eruption occurs.

Mendez, J. S.; Dufek, J.

2012-12-01

31

Argumentation in the Chemistry Laboratory: Inquiry and Confirmatory Experiments  

NASA Astrophysics Data System (ADS)

One of the goals of science education is to provide students with the ability to construct arguments—reasoning and thinking critically in a scientific context. Over the years, many studies have been conducted on constructing arguments in science teaching, but only few of them have dealt with studying argumentation in the laboratory. Our research focuses on the process in which students construct arguments in the chemistry laboratory while conducting various types of experiments. It was found that inquiry experiments have the potential to serve as an effective platform for formulating arguments, owing to the features of this learning environment. The discourse during inquiry-type experiments was found to be rich in arguments, whereas that during confirmatory-type experiments was found to be sparse in arguments. The arguments, which were developed during the discourse of an open inquiry experiment, focus on the hypothesis-building stage, analysis of the results, and drawing appropriate conclusions.

Katchevich, Dvora; Hofstein, Avi; Mamlok-Naaman, Rachel

2013-02-01

32

Laboratory experience for teaching sensory physiology  

NSDL National Science Digital Library

The major challenge in laboratory teaching is the application of abstract concepts in simple and direct practical lessons. However, students rarely have the opportunity to participate in a laboratory that combines practical learning with a realistic research experience. In the Bioengineering Department, we started an experiential laboratory physiology to teach graduated students some aspects of sensorial physiology and exposes them to laboratory skills in instrumentation and physiological measurements. Students were able to analyze and quantify the effects of activation of mechanoreceptors in multifiber afferent discharges using equipment that was not overly sophisticated. In consequence, this practical laboratory helps students to make connections with physiological concepts acquired in theoretical classes and to introduce them to electrophysiological research.

PhD Jonathan Kibble (St. George's University Department of Physiology and Neuroscience)

2009-06-01

33

Cell biology experiments conducted in space  

NASA Technical Reports Server (NTRS)

A review of cell biology experiments conducted during the first two decades of space flight is provided. References are tabulated for work done with six types of living test system: isolated viruses, bacteriophage-host, bacteria, yeasts and filamentous fungi, protozoans, and small groups of cells (such as hamster cell tissue and fertilized frog eggs). The general results of studies involving the survival of cells in space, the effect of space flight on growing cultures, the biological effects of multicharged high-energy particles, and the effects of space flight on the genetic apparatus of microorganisms are summarized. It is concluded that cell systems remain sufficiently stable during space flight to permit experimentation with models requiring a fixed cell line during the space shuttle era.

Taylor, G. R.

1977-01-01

34

Laboratory and Field Experiments in Motor Learning.  

ERIC Educational Resources Information Center

This manual for research in motor learning was written for scientifically based physical educators, experimental psychologists, and others interested in the investigation of learning and performance phenomena associated with skill acquisition. Laboratory and field experiments are presented that can be run with or without the presence of a formal…

Singer, Robert N.; And Others

35

Electrostatic Potential on a Laboratory Measurement Experiment.  

ERIC Educational Resources Information Center

Described is a laboratory experiment in measurement of electrostatic potentials to help students gain an idea of potentials, which will provide a basis for deeper understanding of electricity and magnetism. The theoretical potential in this report is derived by taking into account the boundary of the actual experimental setup. (Author/DS)

Murata, Hiroshi; Sakuraoka, Mitsuru

1980-01-01

36

Laboratory experiments on arc deflection and instability  

SciTech Connect

This article describes experiments on arc deflection instability carried out during the past few years at the Princeton University Plasma Physics Laboratory (PPPL). The approach has been that of plasma physicists interested in arcs, but they believe these results may be useful to engineers who are responsible for controlling arc behavior in large electric steel furnaces.

Zweben, S.; Karasik, M.

2000-03-21

37

Laser Mode Structure Experiments for Undergraduate Laboratories.  

ERIC Educational Resources Information Center

Experiments dealing with laser mode structure are presented which are suitable for an upper division undergraduate laboratory. The theory of cavity modes is summarized. The mode structure of the radiation from a helium-neon laser is measured by using a photodiode detector and spectrum analyzer to detect intermode beating. Off-axial modes can be…

Phillips, Richard A.; Gehrz, Robert D.

38

Heat, Light, and Videotapes: Experiments in Heat Conduction Using Liquid Crystal Film.  

ERIC Educational Resources Information Center

Presents a range of experiments in heat conduction suitable for upper-level undergraduate laboratories that make use of heat sensitive liquid crystal film to measure temperature contours. Includes experiments mathematically described by Laplace's equation, experiments theoretically described by Poisson's equation, and experiments that involve…

Bacon, Michael E.; And Others

1995-01-01

39

Laboratory experiments on mountain-induced rotors  

NASA Astrophysics Data System (ADS)

The problem of mountain-induced rotors has received considerable interest in recent years, which cumulated in the large international field experiment T-REX (Grubisic et al, 2008). Also several numerical simulations on the formation of rotors have been published recently (e.g. Vosper, 2004; Doyle and Durran, 2007). Although much insight into the rotor problem has been gathered through these activities, some additional information might be provided by laboratory experiments in stratified towing tanks. This kind of research has been used frequently with respect to the lee wave problem (e.g. Eiff and Bonneton, 2000), but not many systematic laboratory experiments on the rotor problem have been performed. Here we present some results on laboratory experiments on the formation of mountain-induced rotors, which have been performed in the large towing tank (22.0 m length, 3.0 m width, 1,5 m hight) of Meteo-France at Toulouse. The new aspect of our experiments is the use of variable vertical stratification as compared to the usual linear density profile (constant Brunt-Vaisala frequency) as used in the same tank by Eiff and Bonneton (2000). In fact we were guided by the numerical simulations of Vosper (2004) who has shown, that an elevated inversion (density jump) above the mountain top is favourable for the formation of rotors on the lee side slope. These simulations have provided information, under which combinations of inversion height, inversion strength and upstream wind speed rotors, lee waves or hydraulic jumps can be expected. By proper scaling of the experimental set up we were able, to find these mountain-induced phenomena also in our laboratory experiments within nearly the same parameter range as in the simulations of Vosper. The flow phenomena were made visible by streakline photographs. The velocity fields within lee waves and rotors were obtained by a PIV method. By this we were also able to perform some quantitative comparison with results from numerical simulations, especially concerning the return flow in the lower part of rotors and the sweeping of boundary layer vorticity into the upper part of rotors. Our laboratory experiments confirm, that an elevated inversion is supporting the formation of rotors in the lee side of mountains, as was already indicated in numerical simulations mentioned above. Doyle, J.D. and D.D. Durran: J.Atmos.Sci, 64, 4202-4221 (2007). Eiff, O.S. and P. Bonneton: Phys.Fluids, 12, 1073-1086 (2000). Grubisic, V. et al.: Bull.Amer.Meteor.Soc., 89, 1513-1533 (2008). Vosper, S.B.: Quart.J.Roy.Meteor.Soc., 130, 1723-1748 (2004).

Knigge, C.; Etling, D.; Paci, A.; Eiff, O.

2010-09-01

40

Monitoring hydraulic fracture growth: Laboratory experiments  

SciTech Connect

The authors carry out small-scale hydraulic fracture experiments to investigate the physics of hydraulic fracturing. The laboratory experiments are combined with time-lapse ultrasonic measurements with active sources using both compressional and shear-wave transducers. For the time-lapse measurements they focus on ultrasonic measurement changes during fracture growth. As a consequence they can detect the hydraulic fracture and characterize its shape and geometry during growth. Hence, this paper deals with fracture characterization using time-lapse acoustic data. Hydraulic fracturing is used in the oil and gas industry to stimulate reservoir production.

Groenenboom, J.; Dam, D.B. van

2000-04-01

41

Comparison of Laboratory and Field Methods for Determining the Quasi-Saturated Hydraulic Conductivity of Soils  

SciTech Connect

Laboratory and field ponded infiltration tests in quasi-saturated soils (containing entrapped air) exhibit the same three-stage temporal variability for the flow rate and hydraulic conductivity. However, the values for the hydraulic conductivity may differ by as much as two orders of magnitude due to differences in the geometry and physics of flow when different laboratory and field methods are applied. The purpose of this paper is to investigate this variability using a comparison of results of ponded infiltration tests conducted under laboratory conditions using confined cores, with results of field tests conducted using partially isolated cores and double-ring infiltrometers. Under laboratory conditions in confined cores, during the firs stage, the water flux decreases over time because entrapped air plugs the largest pores in the soils; during the second stage, the quasi-saturated hydraulic conductivity increases by one to two orders of magnitude, essentially reaching the saturated hydraulic conductivity, when entrapped air is discharged from the soils; during the third stage, the hydraulic conductivity decreases to minimum values due to sealing of the soil surface and the effect of biofilms sealing the pores within the wetted zone. Under field conditions, the second stage is only partially developed, and when the surface sealing process begins, the hydraulic pressure drops below the air entry value, thereby causing atmospheric air to enter the soils. As a result, the soils become unsaturated with a low hydraulic conductivity, and the infiltration rate consequently decreases. Contrary to the laboratory experiments in confined cores, the saturated hydraulic conductivity cannot be reached under field conditions. In computations of infiltration one has to take into account the variations in the quasi-saturated and unsaturated hydraulic conductivities, moisture and entrapped air content, and the hydraulic gradient in the quasi-saturated or unsaturated soils.

Faybishenko, Boris

1997-08-01

42

Simple undergraduate lab experiment showing the quantized conductance of nanocontacts  

NSDL National Science Digital Library

Describes an undergraduate experiment on the quantized conductance of nanocontacts. The basic experiment may be performed with very little equipment beyond a digital oscilloscope. A method to explain quantized conductance to undergraduate students is also presented.

Candela, D.

2012-06-06

43

Laboratory experiments from the toy store  

NASA Technical Reports Server (NTRS)

The following is a laboratory experiment designed to further understanding of materials science. This material could be taught to a typical student of materials science or manufacturing at the high school level or above. The objectives of this experiment are as follows: (1) to qualitatively demonstrate the concepts of elasticity, plasticity, and the strain rate and temperature dependence of the mechanical properties of engineering materials; (2) to qualitatively demonstrate the basics of extrusion including material flow, strain rate dependence of defects, lubrication effects, and the making of hollow shapes by extrusion (the two parts may be two separate experiments done at different times when the respective subjects are covered); and (3) to demonstrate the importance of qualitative observations and the amount of information which can be gathered without quantitative measurements.

Mcclelland, H. T.

1992-01-01

44

Controlled Space Physics Experiments using Laboratory Magnetospheres  

NASA Astrophysics Data System (ADS)

Modern society's reliance on space-based platforms for a variety of economic and geopolitical purposes makes understanding the physics of the magnetosphere and "space weather'' one of the most important applications of plasma science. During the past decade, results from the CTX and LDX laboratory magnetospheres and from the RT-1 device at University of Tokyo, we have developed techniques to explore space physics using controlled experiments in laboratory magnetospheres. This presentation briefly reviews observations from the laboratory magnetospheres at Columbia University and MIT, including adiabatic drift-resonant transport, low-frequency MHD turbulence, and the formation of high-beta plasmas with profiles similar to Earth's inner magnetosphere. First principle validation of ``whole plasma'' space weather models have been completed in relevant magnetic geometry, including the spectrum and dynamics of turbulence successfully modeled with nonlinear bounce-averaged gyrokinetic simulations. Plans to explore Alfvénic dynamics and whistler wave trapping are discussed through the achievement of higher-density plasmas using radio-frequency heating. Photographs of the laboratory magnetospheres located at MIT (top) and Columbia University (bottom).

Mauel, M. E.; Kesner, J.; Garnier, D.

2013-12-01

45

Thermal-blooming laboratory experiments. (Reannouncement with new availability information)  

SciTech Connect

The authors conducted a multiphase series of laboratory experiments to explore the adaptive optics compensation of a laser beam distorted by strong thermal blooming. Their experimental approach was to create on a small, low-power beam the same phase distortion that would be experienced by a large, high-power beam propagating through the atmosphere and to apply phase compensation via deformable mirrors. The authors performed the investigations to lay the foundation for future ground-based laser experiments and their corresponding atmospheric-propagation computer models.

Johnson, B.

1992-12-31

46

Episodic Magnetic Tower Jets in Laboratory Experiments  

NASA Astrophysics Data System (ADS)

Results from laboratory astrophysics experiments showing the formation of episodic plasma jets will be presented. The jets are highly supersonic, radiatively cooled and driven by the pressure of the toroidal magnetic field in a `magnetic tower' configuration. The 1 MA, 250 ns current pulse from the MAGPIE generator is introduced into a radial foil, an aluminium disc held between two concentric electrodes. The ablation of plasma from the foil close to the central electrode forms a radial gap which triggers the formation of the jets. Several diagnostics including magnetic and inductive probes were used to study their dynamics, particularly their launching mechanism. The similarities with previous single-episode magnetic tower jets from radial wire arrays together with new measurements of dimensionless parameters such as the magnetic Reynolds number (ReM>400) indicate that the experiments can be scaled to astrophysical jets.

Suzuki-Vidal, F.; Lebedev, S. V.; Bland, S. N.; Burdiak, G.; Chittenden, J. P.; Hall, G. N.; Harvey-Thompson, A. J.; Khoory, E.; Pickworth, L.; Swadling, G.; Ciardi, A.; Stehle, C.

2009-11-01

47

Variable conductance heat pipes from the laboratory to space  

NASA Technical Reports Server (NTRS)

Heat pipes were developed which can be used as (1) a variable conductance link between a heat source and sink which provides temperature stability; (2) a feedback control mechanism that acts to directly maintain the source at a constant temperature; (3) or as a thermal diode that allows heat to be transferred in one direction only. To establish flight level confidence in these basic control techniques, the Ames Heat Pipe Experiment (AHPE) was launched in August 1972 and the Advanced Thermal Control Flight Experiment (ATFE) is scheduled for launch in May 1973. The major efforts of the technology development, initial flight results of the AHPE, and ground test data of the ATFE are discussed.

Kirkpatrick, J. P.

1973-01-01

48

Experiment definition phase shuttle laboratory LDRL-10.6 experiment  

NASA Technical Reports Server (NTRS)

This report for the Experiment Definition Phase of the Shuttle Laboratory LDRL 10.6 Micrometer Experiment covers period 27 June through 26 September 1975. Activities during the fifth quarter included: (1) reevaluation of system obscuration ratio with a subsequent reduction of this ratio from 0.417 to 0.362, (2) completion of detail drawings for the 6X pre-expander, (3) completion of detail drawings for the nine mirrors that comprise pointing and tracking optomechanical subsystem, (4) continuation of detailing of mechanical portions of CMSS and modifications to accommodate new obscuration ratio, (5) qualitative operation of the optomechanical subsystem of the 10.6 um receiver achieved under experiment measurement task; receiver fully integrated and operation demonstrated over a 10 km experimental link, and (6) data collection task initiated to begin preparation of link analysis volumes.

1975-01-01

49

Conductance of Ion Channels - Theory vs. Experiment  

NASA Technical Reports Server (NTRS)

Transmembrane ion channels mediate a number of essential physiological processes in a cell ranging from regulating osmotic pressure to transmission of neural signals. Kinetics and selectivity of ion transport is of critical importance to a cell and, not surprisingly, it is a subject of numerous experimental and theoretical studies. In this presentation we will analyze in detail computer simulations of two simple channels from fungi - antiamoebin and trichotoxin. Each of these channels is made of an alpha-helical bundle of small, nongenomically synthesized peptides containing a number of rare amino acids and exhibits strong antimicrobial activity. We will focus on calculating ionic conductance defined as the ratio of ionic current through the channel to applied voltage. From molecular dynamics simulations, conductance can be calculated in at least two ways, each involving different approximations. Specifically, the current, given as the number of charges transferred through the channel per unit of time, can be obtained from the number of events in which ions cross the channel during the simulation. This method works well for large currents (high conductance values and/or applied voltages). If the number of crossing events is small, reliable estimates of current are difficult to achieve. Alternatively, conductance can be estimated assuming that ion transport can be well approximated as diffusion in the external potential given by the free energy profile. Then, the current can be calculated by solving the one-dimensional diffusion equation in this external potential and applied voltage (the generalized Nernst-Planck equation). To do so three ingredients are needed: the free energy profile, the position-dependent diffusion coefficient and the diffusive flux of ions into the channel. All these quantities can be obtained from molecular dynamics simulations. An important advantage of this method is that it can be used equally well to estimating large and small currents. In addition, once the free energy profile becomes available the full current-voltage dependence can be readily obtained. For both channels we carried out calculations using both approaches. We also tested the main assumptions underlying the diffusive model, such as uncorrelated nature of individual crossing events and Fickian diffusion. The accuracy and consistency of different methods will be discussed. Finally we will discuss how comparisons between calculated and measured ionic conductance and selectivity of transport can be used for determining structural models of the channels.

Pohorille, Andrew; Wilson, Michael; Mijajlovic, Milan

2013-01-01

50

Research and the planned Space Experiment Research and Processing Laboratory  

NASA Technical Reports Server (NTRS)

Original photo and caption dated October 8, 1991: 'Plant researchers Lisa Ruffe and Neil Yorio prepare to harvest a crop of Waldann's Green Lettuce from KSC's Biomass Production Chamber (BPC). KSC researchers have grown several different crops in the BPC to determine which plants will better produce food, water and oxygen on long-duration space missions.' Their work is an example of the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

2000-01-01

51

Research and the planned Space Experiment Research and Processing Laboratory  

NASA Technical Reports Server (NTRS)

Original photo and caption dated October 8, 1991: 'Plant researchers Neil Yorio and Lisa Ruffe prepare to harvest a crop of Waldann's Green Lettuce from KSC's Biomass Production Chamber (BPC). KSC researchers have grown several different crops in the BPC to determine which plants will better produce food, water and oxygen on long-duration space missions.' Their work is an example of the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

2000-01-01

52

Electrical conductivity measurements from the STRATCOM 8 experiment  

NASA Technical Reports Server (NTRS)

A blunt probe experiment for measuring electrical conductivity was flown with the STRATCOM 8 instrument package. Data were obtained by the instrument throughout the entire measurement period. A preliminary analysis of the data indicates an enhancement in conductivity associated with the krypton discharge ionization lamp, particularly in negative conductivity. The conductivity values and their altitude dependence are consistent with previous balloon and rocket results.

Mitchell, J. D.; Ho, K. J.; Half, L. C.; Croskey, C. L.; Olsen, R. O.

1978-01-01

53

Laboratory experiments simulating solar wind driven magnetospheres  

SciTech Connect

Magnetosphere-solar wind interactions are simulated in a laboratory setting with a small permanent magnet driven by two types of supersonic plasma wind sources. The first higher speed, shorter duration plasma wind is from a laser blow-off plasma while the second longer duration, lower speed plasma wind is produced with a capacitor discharge driven coaxial electrode creating plasma jets. The stand off distance of the solar wind from the magnetosphere was measured to be 1.7{+-}0.3 cm for the laser-produced plasma experiment and 0.87{+-}0.03 cm for the coaxial electrode plasma experiment. The stand off distance of the plasma was calculated using data from HYADES[J. T. Larsen and S. M. Lane, J. Quant. Spectrosc. Radiat. Transf. 51, 179 (1994)] as 1.46{+-}0.02 cm for the laser-produced plasma, and estimated for the coaxial plasma jet as r{sub mp}=0.72{+-}0.07 cm. Plasma build up on the poles of the magnets, consistent with magnetosphere systems, was also observed.

Brady, P.; Ditmire, T. [Fusion Research Center, The University of Texas at Austin, Austin, Texas 78712 (United States); Horton, W.; Mays, M. L. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Zakharov, Y. [Institute of Laser Physics, Russian Academy of Sciences, Novosibirsk 630090, Av. Lavrentyeva 13/3 (Russian Federation)

2009-04-15

54

Video recording laboratory experiments for open laboratory environments  

Microsoft Academic Search

In a 400-level CIMT (computer-integrated manufacturing technology) class entitled Manufacturing Applications of Sensor Technology, a series of laboratory assignments has been developed to teach PLC (programmable logic controller)-based and PC-based data acquisition, as well as how sensors play a vital role in CIM environments. Student feedback suggested that laboratory assignments would require less time and the students would learn the

T. E. Kostek

1991-01-01

55

Laboratory Studies to Examine the Impact of Polyacrylamide (PAM) on Soil Hydraulic Conductivity  

NASA Astrophysics Data System (ADS)

Polyacrylamide (PAM) is a long-chain synthetic polymer made of the monomer acrylamide (AMD). PAM has numerous uses ranging from food processing to drilling to wastewater treatment. More recently it has been proposed as a canal sealant in the western US to improve water conservation. To support a larger field-based experimental program being implemented in Grand Junction, CO, soil column experiments are being conducted to evaluate the mechanisms of how, and to what extent, PAM reduces soil hydraulic conductivity. The goal of the experiments is to find the optimum concentration and application method of PAM that reduces hydraulic conductivity to the greatest extent. Column tests were conducted, in triplicate, using a constant head method in acrylic columns of 15 cm length and 6.4 cm diameter. An unbalanced multi-factorial design was used with experimental variables including soil type (medium silica sand, locally-derived sand, and locally-derived loam), PAM concentration (11, 22, 44, 88 kg/canal-ha), turbidity (0, 100, 350 NTU), and application method (hydrated PAM on dry soil and powdered PAM applied to water column above saturated soil). Non-crosslinked anionic PAM with a molecular weight of 12 to 24 Mg/mol was used for all experiments. Additional experiments were conducted in graduated cylinders to evaluate interactions between PAM, turbidity and water chemistry. Results of the laboratory tests will be presented and discussed in the context of water conservation in the western US.

Moran, E. A.; Young, M. H.; Yu, Z.

2005-12-01

56

Laboratory and in-Flight Experiments to Evaluate 3-D Audio Display Technology.  

National Technical Information Service (NTIS)

Laboratory and in-flight experiments were conducted to evaluate 3-D audio display technology for cockpit applications. A 3-D audio display generator was developed which digitally encodes naturally occurring direction information onto any audio signal and ...

M. Ericson R. Mckinley M. Kibbe D. Francis

1994-01-01

57

Organic Laboratory Experiments: Micro vs. Conventional.  

ERIC Educational Resources Information Center

Presents relevant statistics accumulated in a fall organic laboratory course. Discusses laboratory equipment setup to lower the amount of waste. Notes decreased solid wastes were produced compared to the previous semester. (MVL)

Chloupek-McGough, Marge

1989-01-01

58

The design and development of a space laboratory to conduct magnetospheric and plasma research  

NASA Technical Reports Server (NTRS)

A design study was conducted concerning a proposed shuttle-borne space laboratory for research on magnetospheric and plasma physics. A worldwide survey found two broad research disciplines of interest: geophysical studies of the dynamics and structure of the magnetosphere (including wave characteristics, wave-particle interactions, magnetospheric modifications, beam-plasma interactions, and energetic particles and tracers) and plasma physics studies (plasma physics in space, wake and sheath studies, and propulsion and devices). The Plasma Physics and Environmental Perturbation Laboratory (PPEPL) designed to perform experiments in these areas will include two 50-m booms and two maneuverable subsatellites, a photometer array, standardized proton, electron, and plasma accelerators, a high-powered transmitter for frequencies above 100 kHz, a low-power transmitter for VLF and below, and complete diagnostic packages. Problem areas in the design of a space plasma physics laboratory are indicated.

Rosen, A.

1974-01-01

59

GUIDELINES FOR CONDUCTING SINGLE LABORATORY EVALUATIONS OF BIOLOGICAL METHODS  

EPA Science Inventory

The single laboratory test is used to establish the data quality that can be achieved within a single laboratory. It provides a basis for deciding whether or not a given method merits collaborative testing and it more clearly defines a method's potential for inclusion as part of ...

60

Guidelines for Conducting Single Laboratory Evaluations of Biological Methods.  

National Technical Information Service (NTIS)

The single laboratory test is used to establish the data quality that can be achieved within a single laboratory. It provides a basis for deciding whether or not a given method merits collaborative testing and it more clearly defines a method's potential ...

W. D. McKenzie T. A. Olsson

1983-01-01

61

Research and the planned Space Experiment Research and Processing Laboratory  

NASA Technical Reports Server (NTRS)

Original photo and caption dated August 14, 1995: 'KSC plant physiologist Dr. Gary Stutte (right) and Cheryl Mackowiak harvest potatoes grown in the Biomass Production Chamber of the Controlled Enviornment Life Support System (CELSS in Hangar L at Cape Canaveral Air Station. During a 418-day 'human rated' experiment, potato crops grown in the chamber provided the equivalent of a continuous supply of the oxygen for one astronaut, along with 55 percent of that long-duration space flight crew member's caloric food requirements and enough purified water for four astronauts while absorbing their expelled carbon dioxide. The experiment provided data that will help demonstarte the feasibility of the CELSS operating as a bioregenerative life support system for lunar and deep-space missions that can operate independently without the need to carry consumables such as air, water and food, while not requiring the expendable air and water system filters necessary on today's human-piloted spacecraft.' Their work is an example of the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

2000-01-01

62

COLUMN EXPERIMENTS AND ANOMALOUS CONDUCTIVITY IN HYDROCARBON-IMPACTED SOILS  

EPA Science Inventory

A laboratory experiment was designed to increase the understanding of the geoelectric effects of microbial " degradation of hydrocarbons. Eight large columns were were paired to provide a replicate of each of four experiments. These large-volume columns contained "sterilized" soi...

63

A Ku-band laboratory experiment on the electromagnetic bias  

SciTech Connect

Sea-surface electromagnetic bias (EM bias), the difference between the mean reflecting surface and the geometric mean sea level, must be accurately determined to realize the full potential of satellite altimeters. A uniformly valid algorithm relating the normalized (or nondimensional) EM bias, i.e., ``bias/significant wave height,`` to physical variables has not yet been established, so the authors conducted laboratory experiments to guide model development. Dimensional relations seldom yield robust algorithms and in fact, although rather high correlation is found between normalized EM bias and either wind speed or wave height, the laboratory coefficients are considerably greater than those of in situ algorithms. Nondimensional parameterization is more useful for deriving scaling laws, and when the normalized EM bias is displayed as a function of wave height skewness or wave age, laboratory and field data converge into consistent trends. In particular, normalized bias decreases with wave age, but unfortunately, even the wave age model does not account for the effects of mechanically generated waves, which produce appreciable scatter relative to the pure wind cases. Thus, they propose a two-parameter model using (1) a nondimensional wave height, which is computed for local winds, and (2) a significant slope, which is computed for nonlocally generated waves. Analysis of the laboratory data shows that the normalized EM bias for mixed conditions is well modeled as a product of these two parameters.

Branger, H.; Ramamonjiarisoa, A. [Inst. de Mecanique Statistique de la Turbulence, Marseille (France)] [Inst. de Mecanique Statistique de la Turbulence, Marseille (France); Bliven, L.F. [NASA, Wallops Island, VA (United States). Wallops Flight Facility] [NASA, Wallops Island, VA (United States). Wallops Flight Facility

1993-11-01

64

The laboratory experience in introductory physics courses  

NASA Astrophysics Data System (ADS)

The last two decades or so have witnessed intense efforts to improve the teaching and learning of physics. Scholarly studies have provided the grounding for many projects which reform the structure of introductory courses. A number of these innovations, however, are resource intensive, or depend on the ability to introduce changes in areas which are beyond the control of the faculty (e.g., scheduling), thus inhibiting their implementation. An alternative strategy that overcomes these obstacles is to modify the nature of the laboratory experience (a component that practically nobody disputes is an essential part of the introductory course), to provide hands-on learning opportunities that differ from the traditional ``follow-this-recipe-to-verify-this-law'' approach. I have chosen to implement a variety of activities that support the overall objectives of the course: developing conceptual understanding and transferable skills, and providing practice in the ways scientists actually do science. Given the audience in this two-semester, algebra-based course, mostly biology majors and pre-professionals (health-related careers, such as medicine, physical therapy, and veterinary), these goals were identified as the most important and lasting contribution that a physics course can make to the students intellectual development. I offer here examples of the types of hands on activities that I have implemented, organized for the sake of this presentation in four rather loose categories, depending on which subset of the course objectives the activities mostly address: self-designed lab activities, discussion of demo-type activities, building concepts from simple to complex, and out-of-lab physical phenomena.

di Stefano, Maria C.

1997-03-01

65

Zero-gravity cloud physics laboratory: Experiment program definition and preliminary laboratory concept studies  

NASA Technical Reports Server (NTRS)

The experiment program definition and preliminary laboratory concept studies on the zero G cloud physics laboratory are reported. This program involves the definition and development of an atmospheric cloud physics laboratory and the selection and delineations of a set of candidate experiments that must utilize the unique environment of zero gravity or near zero gravity.

Eaton, L. R.; Greco, E. V.

1973-01-01

66

Do-It-Yourself Experiments for the Instructional Laboratory  

ERIC Educational Resources Information Center

A new design for experiments in the general chemistry laboratory incorporates a "do-it-yourself" component for students. In this design, students perform proven experiments to gain experience with techniques for about two-thirds of a laboratory session and then spend the last part in the do-it-yourself component, applying the techniques to an…

Craig, Norman C.; Hill, Cortland S.

2012-01-01

67

Remotely controlled laboratory experiments: Creation and examples  

Microsoft Academic Search

Most users who can only connect to their university through distance learning enabled programs have no other choice than to sit out the experimental side of education. Remote Labs have the greatest potential to overcome the bottleneck in distance education. The goal of Remote Laboratory implementation is to grant these students access to laboratory equipment. Although there is not currently

A. Hyder; S. K. Choi; D. Schaefer

2010-01-01

68

A laboratory acoustic emission experiment under in situ conditions  

NASA Astrophysics Data System (ADS)

In this paper, we revisit acoustic emission (AE) data from an in situ rock fracture experiment conducted at the Underground Research Laboratory (URL) in Manitoba, Canada. The Mine-By experiment, a large-scale excavation response test, was undertaken at a depth of 420 m and involved the mechanical excavation of a cylindrical tunnel. During the experiment a small array of 16 Panametrics V103 AE sensors enclosed a 0.7 m × 0.7 m × 1.1 m rectangular prism of Lac du Bonnet granite located in the tunnel wall. The V103 sensors were later calibrated in the laboratory, and a source parameter analysis was undertaken using a spectral fitting method. Corner frequency and moment magnitude were found to be inside the ranges 250 kHz

Goodfellow, S. D.; Young, R. P.

2014-05-01

69

Results from the cascaded variable conductance heatpipe experiment on LDEF  

NASA Technical Reports Server (NTRS)

A Variable Conductance Heat Pipe Experiment (CVCHPE) was successfully flown onboard the LDEF and demonstrated temperature control better than +/- 0.3 C during 50 days of on-orbit data collection in a widely varying external environment. The experiment used two series connected, dry reservoir variable conductance heat pipes which require no electrical power for operation. The heat pipes used a central artery design with ammonia working fluid and nitrogen control gas.

Grote, Michael G.

1991-01-01

70

Asteroid Regolith Mechanical Properties: Laboratory Experiments With Cohesive Powders  

NASA Astrophysics Data System (ADS)

Despite clear evidence that small asteroids undergo drastic physical evolution, the geophysics and mechanics of many of the processes governing that evolution remain a mystery due to a lack of scientific data, both on the sub-surface and global geophysics of these small bodies and on the mechanical properties of regoliths in the unique micro-gravity regime they inhabit. We are beginning a three-year effort to study regolith properties and processes on low-gravity, small asteroids by conducting analog experiments with cohesive powders in a 1-g laboratory environment. Based on a rigorous comparison of forces it can be shown that van der Waals cohesive forces between millimeter to centimeter-sized grains on asteroids ranging in size from Eros to Itokawa, respectively, may exceed their ambient weight several-fold. This observation implies that regoliths composed of impact debris of those sizes should behave on the microgravity surfaces of small asteroids like flour or other cohesive powders do in the 1-g environment here on Earth. Our goal is to develop an improved understanding of the role of cohesion in affecting regolith processes and surface morphology of small Solar System bodies, some the targets of ongoing and proposed NASA New Frontiers and Discovery missions, and to quantify the range of expected mechanical properties of such regoliths. Our experiments will be conducted in ambient and vacuum conditions within an environmental test chamber at Ball Aerospace & Technologies Corporation (BATC) in Boulder, CO. To aid in validating our experiment chamber and support equipment performance, and before proceeding with experiments on geologic regolith simulant materials, we will perform a series of comparative, ‘calibration’ experiments with micro glass spheres; all primary experiments will be performed with at least one non-idealized regolith simulant, like JSC-1, that more realistically simulates the angular particle shapes expected in actual geologic fragments generated from impact comminution.

Durda, Daniel D.; Scheeres, D. J.; Roark, S. E.; Dissly, R.; Sanchez, P.

2012-10-01

71

Secondary beams and dose enhancement experiment at Brookhaven National Laboratories  

SciTech Connect

Over the past three years, several experiments have been conducted at the Brookhaven National Laboratory Radiation Effects Facility. These experiments have been investigations of proton induced radiation effects in individual electronic components, circuits, operational subsystems and full systems. Our investigations using 170--200 MeV protons have included total dose effects up to 12 Mrad, dose rate effects of the ionizing radiation in the 10{sup 5} to 10{sup 8} rad/s range, the displacement damage effects of the protons up to 10{sup 15} p/cm{sup 2}, and the proton induced thermal shift and thermal-rate effects. The target thickness of many test devices was an appreciable fraction of the range of 200 MeV protons. In our proton beam testing experiments at BNL, dosimetry placed downstream of the target consistently yielded higher dose in rad and in particle fluence than in dosimetry placed upstream of the target. We designed and performed an experiment to study this dose enhancement. The objective of the experiment was to determine the effect of sample thickness on our three methods of dosimetry. The data from the PIN diodes and tantalum calorimeters were consistent and followed the expected DE/DX curve. They show a dose enhancement effect. The proton beam interacts and loses energy as it travels through thick targets. The exiting lower energy beam deposits more energy into the dosimetry because the stopping power increases with decreasing proton energy.

Tanner, D.M.; Calocci, T.F.; Posey, L.D.; Bonaparte, S.D.; Romero, R.L.; Zarick, T.A. (Sandia National Labs., Albuquerque, NM (United States)); Beeson, D.E. (Ktech Corp., Albuquerque, NM (United States))

1991-01-01

72

An Experiment in Heat Conduction Using Hollow Cylinders  

ERIC Educational Resources Information Center

An experimental apparatus was designed and built to allow students to carry out heat conduction experiments in hollow cylinders made of different materials, as well as to determine the thermal conductivity of these materials. The evolution of the temperature difference between the inner and outer walls of the cylinder as a function of time is…

Ortuno, M.; Marquez, A.; Gallego, S.; Neipp, C.; Belendez, A.

2011-01-01

73

Cosmic Microwave Background Radiation (CMB) explained using Modern Einstein (Gedanken) Laboratory Experiments  

NASA Astrophysics Data System (ADS)

Three explanations presented: two old school, unsupported by physics, and a brand new one that best explains all the NASA CMB observations, further incorporates many current experiments conducted by Stanford - SLAC National Accelerator Laboratory among other equivalent organizations, including a very simple setup that may be reproduced in any laboratory designed by the author.

Sven, Charles

2012-04-01

74

Laboratory Experiments, Numerical Simulations, and Astronomical Observations of Deflected Supersonic Jets: Application to HH 110  

Microsoft Academic Search

Collimated supersonic flows in laboratory experiments behave in a similar manner to astrophysical jets provided that radiation, viscosity, and thermal conductivity are unimportant in the laboratory jets and that the experimental and astrophysical jets share similar dimensionless parameters such as the Mach number and the ratio of the density between the jet and the ambient medium. When these conditions apply,

P. Hartigan; J. M. Foster; B. H. Wilde; R. F. Coker; P. A. Rosen; J. F. Hansen; B. E. Blue; R. J. R. Williams; R. Carver; A. Frank

2009-01-01

75

Laboratory Experiments for Undergraduate Instruction in Economics.  

ERIC Educational Resources Information Center

Describes the generation and use of experimental data in teaching economics. Includes a double oral auction experiment and a monopoly pricing experiment. Concludes that such experiments allow the instructor to see what the students have learned, how they reason, and what parts of the material have proved difficult. (DK)

Wells, Donald A.

1991-01-01

76

Principles of Radio: A Laboratory Experiment  

ERIC Educational Resources Information Center

An experiment is proposed for learning the principles of radio. A simple radio receiver illustrates amplitude modulation and demodulation, the selectivity of a receiver and the features of a directional antenna. Both normal and computerized versions of the experiment are described. The computerized experiment employs the "ScienceWorkshop"…

Kraftmakher, Yaakov

2002-01-01

77

The Unstructured Student-Designed Research Type of Laboratory Experiment.  

ERIC Educational Resources Information Center

Discusses the use of an individually designed experiment for a chemical engineering laboratory course. Lists main ideas of the method. Provides an example of the experiment including ways to answer the questions and extensions. (YP)

Macias-Machin, Agustin; And Others

1990-01-01

78

Experiments at the Triangle Universities Nuclear Laboratory for the undergraduate physics curriculum  

SciTech Connect

Experiments are being developed at the Triangle Universities Nuclear Laboratory to offer advanced undergraduate physics students laboratory experiences in the atmosphere of a frontier accelerator facility. These experiments differ from projects done by Undergraduate Research Assistants in that they are designed specifically for integration into the undergraduate curriculum as part of a structured laboratory course. The immediate goal of the program is to develop four accelerator-based experiments for use in the undergraduate Advanced Laboratory course at Duke University. Two newly developed experiments, {ital Carbon-Carbon Mott Scattering} and {ital Lifetime Measurements of an Auger Emitter}, will be described. In addition, the logistics of conducting undergraduate laboratory course work in an active research facility will be discussed. {copyright} {ital 1999 American Institute of Physics.}

Howell, C.R. [Department of Physics, Duke University and the Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)

1999-06-01

79

Experiments at the Triangle Universities Nuclear Laboratory for the undergraduate physics curriculum  

SciTech Connect

Experiments are being developed at the Triangle Universities Nuclear Laboratory to offer advanced undergraduate physics students laboratory experiences in the atmosphere of a frontier accelerator facility. These experiments differ from projects done by Undergraduate Research Assistants in that they are designed specifically for integration into the undergraduate curriculum as part of a structured laboratory course. The immediate goal of the program is to develop four accelerator-based experiments for use in the undergraduate Advanced Laboratory course at Duke University. Two newly developed experiments, Carbon-Carbon Mott Scattering and Lifetime Measurements of an Auger Emitter, will be described. In addition, the logistics of conducting undergraduate laboratory course work in an active research facility will be discussed.

Howell, C. R. [Department of Physics, Duke University and the Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)

1999-06-10

80

Astrophysical jets: Observations, numerical simulations, and laboratory experiments  

SciTech Connect

This paper provides summaries of ten talks on astrophysical jets given at the HEDP/HEDLA-08 International Conference in St. Louis. The talks are topically divided into the areas of observation, numerical modeling, and laboratory experiment. One essential feature of jets, namely, their filamentary (i.e., collimated) nature, can be reproduced in both numerical models and laboratory experiments. Another essential feature of jets, their scalability, is evident from the large number of astrophysical situations where jets occur. This scalability is the reason why laboratory experiments simulating jets are possible and why the same theoretical models can be used for both observed astrophysical jets and laboratory simulations.

Bellan, P. M. [Caltech, Pasadena, California 91125 (United States); Livio, M. [Space Telescope Science Institute, Baltimore, Maryland 21218 (United States); Kato, Y. [University of Tsukuba, Ibaraki 3058577 (Japan); Lebedev, S. V. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Ray, T. P. [Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin 2 (Ireland); Ferrari, A. [Dipartimento di Fisica, Universita di Torino, via Pietro Giuria 1, 10125 Torino, Italy and Department of Astronomy and Astrophysics, University of Chicago, Chicago, Illinois 60637 (United States); Hartigan, P. [Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892 (United States); Frank, A. [Department of Physics and Astronomy and Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14627 (United States); Foster, J. M. [AWE Aldermaston, Reading RG7 4PR (United Kingdom); Nicolaie, P. [Centre Lasers Intenses et Applications, Universite Bordeaux 1-CEA-CNRS, 33405 Talence (France)

2009-04-15

81

Variable Conductance Heat Pipes from the Laboratory to Space.  

National Technical Information Service (NTIS)

Heat pipes were developed which can be used as (1) a variable conductance link between a heat source and sink which provides temperature stability; (2) a feedback control mechanism that acts to directly maintain the source at a constant temperature; (3) o...

J. P. Kirkpatrick

1973-01-01

82

Experiences of Mentors Training Underrepresented Undergraduates in the Research Laboratory  

PubMed Central

Successfully recruiting students from underrepresented groups to pursue biomedical science research careers continues to be a challenge. Early exposure to scientific research is often cited as a powerful means to attract research scholars with the research mentor being critical in facilitating the development of an individual's science identity and career; however, most mentors in the biological sciences have had little formal training in working with research mentees. To better understand mentors’ experiences working with undergraduates in the laboratory, we conducted semistructured interviews with 15 research mentors at a public university in the Midwest. The interviewed mentors were part of a program designed to increase the number of American Indians pursuing biomedical/biobehavioral research careers and represented a broad array of perspectives, including equal representation of male and female mentors, mentors from underrepresented groups, mentors at different levels of their careers, and mentors from undergraduate and professional school departments. The mentors identified benefits and challenges in being an effective mentor. We also explored what the term underrepresented means to the mentors and discovered that most of the mentors had an incomplete understanding about how differences in culture could contribute to underrepresented students’ experience in the laboratory. Our interviews identify issues relevant to designing programs and courses focused on undergraduate student research.

Prunuske, Amy J.; Wilson, Janelle; Walls, Melissa; Clarke, Benjamin

2013-01-01

83

A Laboratory Experiment on the Statistical Theory of Nuclear Reactions  

ERIC Educational Resources Information Center

Describes an undergraduate laboratory experiment on the statistical theory of nuclear reactions. The experiment involves measuring the relative cross sections for formation of a nucleus in its meta stable excited state and its ground state by applying gamma-ray spectroscopy to an irradiated sample. Involves 3-4 hours of laboratory time plus…

Loveland, Walter

1971-01-01

84

Laboratory Experiment on Electrokinetic Remediation of Soil  

ERIC Educational Resources Information Center

Electrokinetic remediation is a method of decontaminating soil containing heavy metals and polar organic contaminants by passing a direct current through the soil. An undergraduate chemistry laboratory is described to demonstrate electrokinetic remediation of soil contaminated with copper. A 30 cm electrokinetic cell with an applied voltage of 30…

Elsayed-Ali, Alya H.; Abdel-Fattah, Tarek; Elsayed-Ali, Hani E.

2011-01-01

85

Description of the Spacecraft Control Laboratory Experiment (SCOLE) facility  

NASA Technical Reports Server (NTRS)

A laboratory facility for the study of control laws for large flexible spacecraft is described. The facility fulfills the requirements of the Spacecraft Control Laboratory Experiment (SCOLE) design challenge for laboratory experiments, which will allow slew maneuvers and pointing operations. The structural apparatus is described in detail sufficient for modelling purposes. The sensor and actuator types and characteristics are described so that identification and control algorithms may be designed. The control implementation computer and real-time subroutines are also described.

Williams, Jeffrey P.; Rallo, Rosemary A.

1987-01-01

86

Description of the Spacecraft Control Laboratory Experiment (SCOLE) facility  

NASA Technical Reports Server (NTRS)

A laboratory facility for the study of control laws for large flexible spacecraft is described. The facility fulfills the requirements of the Spacecraft Control Laboratory Experiment (SCOLE) design challenge for a laboratory experiment, which will allow slew maneuvers and pointing operations. The structural apparatus is described in detail sufficient for modelling purposes. The sensor and actuator types and characteristics are described so that identification and control algorithms may be designed. The control implementation computer and real-time subroutines are also described.

Williams, Jeffrey P.; Rallo, Rosemary A.

1987-01-01

87

Review of subsidence prediction research conducted at Sandia National Laboratories  

SciTech Connect

This paper reviews the results of the subsidence research program at Sandia National Laboratories. The manuscript highlights the following: the application of empirical methods (profile functions) to the subsidence above longwall panels in the US; the use of the rubble model to describe the behavior of broken strata as it distends when it falls to the mine floor (or top of the rubble pile) and then is subsequently compacted as it is loaded by overlying elements of strata; and, the application of physical modeling techniques (centrifuge simulations) and numerical techniques to study the failure mechanisms in highly structured stratigraphy. The capabilities of the latter two are illustrated by comparing their predictions to the results of a field case that has complicated stratigraphy.

Sutherland, H.J.; Schuler, K.W.

1982-04-01

88

Recycle with Heating: A Laboratory Experiment.  

ERIC Educational Resources Information Center

Describes an apparatus (built from domestic plumbing pipes and fittings) that uses only water and electricity (as consumables) to investigate basic mass and heat balances in a system with recycle. Also describes experiments using the apparatus. (JN)

Foord, A.; Mason, G.

1985-01-01

89

Obtaining Valid Laboratory Data in Clinical Trials Conducted in Resource Diverse Settings: Lessons Learned from a Microbicide Phase III Clinical Trial  

Microsoft Academic Search

BackgroundOver the last decade several phase III microbicides trials have been conducted in developing countries. However, laboratories in resource constrained settings do not always have the experience, infrastructure, and the capacity to deliver laboratory data meeting the high standards of clinical trials. This paper describes the design and outcomes of a laboratory quality assurance program which was implemented during a

Tania Crucitti; Katrien Fransen; Rashika Maharaj; Tom Tenywa; Marguerite Massinga Loembé; Kailapuri Gangatharan Murugavel; Kevin Mendonca; Said Abdellati; Greet Beelaert; Lut van Damme; Patricia Kissinger

2010-01-01

90

A review of laboratory measurements of the electrical conductivity of rocks and minerals  

Microsoft Academic Search

The use of laboratory measurements of electrical conductivity for rocks and minerals at high temperatures and pressures helps us to interpret magnetotelluric measurements and allows us to obtain further information about various physical and mineralogical properties of the Earth's interior. A survey of recent laboratory measurements of electrical conductivity of rocks and minerals at high temperatures and pressures is outlined.

Marcela Latoviková

1991-01-01

91

Linking Laboratory Experiences to the Real World: The Extraction of Octylphenoxyacetic Acid from Water  

ERIC Educational Resources Information Center

Several chemical concepts to the extraction of a water pollutant OPC (octylphenoxyacetic acid) is presented. As an introduction to the laboratory experiment, a discussion on endocrine disrupters is conducted to familiarize the student with the background of the experiment and to explain the need for the extraction and quantitation of the OPC which…

Loyo-Rosales, Jorge E.; Torrents, Alba; Rosales-Rivera, Georgina C.; Rice, Clifford C.

2006-01-01

92

Laboratory hydraulic fracturing experiments in intact and pre-fractured rock  

Microsoft Academic Search

Laboratory hydraulic fracturing experiments were conducted to investigate two factors which could influence the use of the hydrofrac technique for in-situ stress determinations; the possible dependence of the breakdown pressure upon the rate of borehole pressurization, and the influence of pre-existing cracks on the orientation of generated fractures. The experiments have shown that while the rate of borehole pressurization has

M. D. Zoback; R. Rummel; R. Jung; C. B. Raleigh

1977-01-01

93

Conductive education for physically handicapped children: parental expectations and experience.  

PubMed Central

Conductive education, an educational approach devised by Andras Petö in Hungary after the second world war, has attracted considerable media attention. Eight Northern Ireland families who recently had treatment for their disabled child at the Petö Institute in Budapest were identified. Six families returned postal questionnaires designed to look at parental experience of conductive education. An improvement in existing local services, as opposed to the wholesale introduction of this facility was the commonest parental hope for future provision for physically handicapped children.

Hill, A. E.

1990-01-01

94

Improving Target Characterization for Laboratory Astrophysics Experiments  

NASA Astrophysics Data System (ADS)

We have fabricated and characterized targets for laboratory astrophysics since 2003, and have made improvements focusing on characterizing particular target features and their variances. Examples of measurements include machined features, material thickness and uniformity, location and thickness of glue, and mating conditions between adjacent materials. Measurements involve new technology and characterization methods, such as pre-shot radiography. More accurate characterization also leads to improvements in fabrication techniques, and helps integrate new technology into our build process. Quantifying variances more precisely also helps us better evaluate each fabrication method for both accuracy and consistency. We present these characterization methods and their impact on fabrication. This work is funded by the Predictive Sciences Academic Alliances Program in NNSA-ASC via grant DEFC52- 08NA28616, by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-FG52-09NA29548, and by the National Laser User Facility Program, grant number DE-FG52-09NA29034.

Marion, D. C.; Grosskopf, M. J.; Kuranz, C. C.; Drake, R. P.; Huntington, C. M.; Doss, F. W.; Krauland, C. M.; Distefano, C. A.

2010-11-01

95

Preparation of Conductive Polymer Polyanilines for an Experiment for Students  

NASA Astrophysics Data System (ADS)

For an organic and polymer chemistry experiment for students in university and college of technology, synthesis of conducting polymers was attempted. Three conductive polymers, polyaniline, poly (o-phenylenediamine) and poly (N-methylaniline) , were prepared by oxidative polymerizations of the corresponding monomers. Among four oxidizing agents, K2Cr2O7, KIO3, FeCl3 and (NH4) 2S2O8, (NH4) 2S2O8 was turned out to be the best oxidizing agent for the polymerizations. The polymerizing solutions gradually colored because of the formation of colored oligomers, which was monitored with the absorption spectra measured during the polymerizations. Since the time for experiment was limited, the molar ratio of [ (NH4) 2S2O8] to [monomer] was taken 2 : 1. The experiment was demonstrated in the organic and polymer chemistry experiments and was evaluated by students as well as teachers.

Yano, Jun; Matsuzaki, Kiyoka; Ichimori, Hayato; Ito, Takeshi; Okano, Hiroshi; Osaki, Nobukazu

96

Integrated verification experiment data collected as part of the Los Alamos National Laboratory`s Source Region program. Appendix F: Regional data from Lawrence Livermore National Laboratory and Sandia National Laboratory Seismic Networks  

SciTech Connect

A dataset of regional seismograms assembled for a series of Integrated Verification Experiments conducted by the Los Alamos National Laboratory Source Region program is described. The seismic data has been assembled from networks operated by Lawrence Livermore National Laboratory and Sandia National Laboratory. Examples of the data are shown and basic recording characteristics of the network are described. The seismograms are available on a data tape in SAC format upon request.

Taylor, S.R.

1993-06-11

97

Simple Laboratory Experiment for Illustrating Soil Respiration.  

ERIC Educational Resources Information Center

Describes an experiment to illustrate the effect of food source and added nutrients (N) on microbial activity in the soil. Supplies include air-dried soil, dried plant material, sources of carbon and nitrogen, a trap such as KOH, colored water, and a 500-mL Erlenmeyer flask. Includes a diagram of an incubation chamber to demonstrate microbial…

Hattey, J. A.; Johnson, G. V.

1997-01-01

98

"Crown Ether" Synthesis: An Organic Laboratory Experiment.  

ERIC Educational Resources Information Center

This experiment is designed to acquaint the student with a macromolecular synthesis of a crown ether type compound. The starting materials are readily available and the product, a cyclic polyether, belongs to a class of compounds that has aroused the interest of chemist and biologist alike. (Author/BB)

Field, Kurt W.; And Others

1979-01-01

99

A Simple Photochemical Experiment for the Advanced Laboratory.  

ERIC Educational Resources Information Center

Describes an experiment to provide students with: (1) an introduction to photochemical techniques and theory; (2) an experience with semimicro techniques; (3) an application of carbon-14 nuclear magnetic resonance; and (4) a laboratory with some qualities of a genuine experiment. These criteria are met in the photooxidation of 9,…

Rosenfeld, Stuart M.

1986-01-01

100

Millikan's Oil-Drop Experiment as a Remotely Controlled Laboratory  

ERIC Educational Resources Information Center

The Millikan oil-drop experiment, to determine the elementary electrical charge e and the quantization of charge Q = n [middle dot] e, is an essential experiment in physics teaching but it is hardly performed in class for several reasons. Therefore, we offer this experiment as a remotely controlled laboratory (RCL). We describe the interactivity…

Eckert, Bodo; Grober, Sebastian; Vetter, Martin; Jodl, Hans-Jorg

2012-01-01

101

Symmetron Dark Energy in Laboratory Experiments  

NASA Astrophysics Data System (ADS)

The symmetron scalar field is a matter-coupled dark energy candidate which effectively decouples from matter in high-density regions through a symmetry restoration. We consider a previously unexplored regime, in which the vacuum mass ?˜2.4×10-3eV of the symmetron is near the dark energy scale, and the matter coupling parameter M˜1TeV is just beyond standard model energies. Such a field will give rise to a fifth force at submillimeter distances which can be probed by short-range gravity experiments. We show that a torsion pendulum experiment such as Eöt-Wash can exclude symmetrons in this regime for all self-couplings ??7.5.

Upadhye, Amol

2013-01-01

102

Symmetron dark energy in laboratory experiments.  

PubMed

The symmetron scalar field is a matter-coupled dark energy candidate which effectively decouples from matter in high-density regions through a symmetry restoration. We consider a previously unexplored regime, in which the vacuum mass ?~2.4×10(-3) eV of the symmetron is near the dark energy scale, and the matter coupling parameter M~1 TeV is just beyond standard model energies. Such a field will give rise to a fifth force at submillimeter distances which can be probed by short-range gravity experiments. We show that a torsion pendulum experiment such as Eöt-Wash can exclude symmetrons in this regime for all self-couplings ? is < or approximately equal to 7.5. PMID:23373910

Upadhye, Amol

2013-01-18

103

Comparing Volcano Infrasound and Aeroacoustics Laboratory Experiments  

NASA Astrophysics Data System (ADS)

The production of acoustic noise by fluid flows has been studied experimentally within engineering aeroacoustics for over 50 years. These works aim to correlate flow properties and dynamics with the produced acoustic spectra (i.e., patterns of frequencies and amplitude). These correlations are used to design flow fields in man-made jet engines and other machines to reduce the production of harmful acoustic signals and resulting hearing loss. Many of the flow fields in these man-made systems are analogous to those in volcanic eruptions. We postulate that the acoustic signals generated by these flows are also analogous and the aeroacoustics experimental results provide a starting point for modeling the noise generated by volcanic flow fields. Application of empirical results from these experiments to volcanic flow fields is non-trivial. Volcanic eruptions involve complexities not present in man-made experiments including but not limited to multiphase flow, buoyancy forces, and non-uniform atmosphere. This work explores methods by which some of the empirical results from aeroacoustics experiments can be modified for application to volcanic eruptions. Results are compared with observations of volcano infrasound. Preliminary comparison to numerical simulations of volcano infrasound may also be presented.

Ogden, D. E.; Matoza, R. S.; Fee, D.

2012-12-01

104

Inventory Control. Easily Made Electronic Device for Conductivity Experiments.  

ERIC Educational Resources Information Center

Describes how to construct an electronic device to be used in conductivity experiments using a 35 millimeter film canister, nine volt battery replacement snaps, a 200-300 ohm resistor, and a light-emitting diode. Provides a diagram and photographs of the device. (TW)

Gadek, Frank J.

1987-01-01

105

First experiences with the rotating laboratory  

NASA Technical Reports Server (NTRS)

This report describes experiences with a rotating cylinder to explore the effects of motion and flow upon human sensory organs. One observation was that the variation of the resultant line of gravity (from gravity and centrifugal force) was not felt so strongly as might be expected. The impressions produced by the physical effects on the members of the body, especially the ones caused by the deflecting force (Coriolis force), are exactly what the laws of physics would lead us to expect, although somewhat surprising when observed in one's own body.

Prandtl, L

1926-01-01

106

High Performance Liquid Chromatography Experiments to Undergraduate Laboratories  

ERIC Educational Resources Information Center

Reviews the principles of liquid chromatography with electrochemical detection (LCEC), an analytical technique that incorporates the advantages of both liquids chromatography and electrochemistry. Also suggests laboratory experiments using this technique. (MLH)

Kissinger, Peter T.; And Others

1977-01-01

107

Laboratory Experiments on the Electrochemical Remediation of the Environment  

ERIC Educational Resources Information Center

Ferrate, which is a strong iron oxidant for removing pollutants from water, is developed electrochemically in the laboratory, and used for experiments simulating environmental situations. Thus, ferrate is a powerful oxidizing agent capable of destroying an immense variety of contaminants.

Ibanez, Jorge G.; Tellez-Giron, Monica; Alvarez, Diana

2004-01-01

108

Analytical Study of the Atmospheric Cloud Physics Laboratory (Acpl) Experiments.  

National Technical Information Service (NTIS)

The design specifications of the research laboratory as a Spacelab facility are discussed along with the types of planned experiments. These include cloud formation, freezing and scavenging, and electrical phenomena. A summary of the program conferences i...

M. H. Davis

1977-01-01

109

Procedure Manuals for the Comparative Systems Laboratory Experiments.  

National Technical Information Service (NTIS)

The report deals with experiments in testing and evaluation of an information retrieval system within the Comparative Systems Laboratory (CSL). The twelve sections of the report reflect the developmental phase of CSL. Section I outlines the approach and t...

T. Saracevic L. Rothenberg

1967-01-01

110

Reaction Kinetics: An Experiment for Biochemistry and Organic Chemistry Laboratories.  

ERIC Educational Resources Information Center

Describes an experiment to examine the kinetics of carbamate decomposition and the effect of buffer catalysis on the reaction. Includes background information, laboratory procedures, evaluation of data, and teaching suggestions. (Author/JN)

Ewing, Sheila

1982-01-01

111

Establishing laboratory standards for biological flight experiments  

NASA Technical Reports Server (NTRS)

The general objective of this research was to assess the effects of exposure to simulated microgravity on ultrastructural aspects of the contractile system in chicken skeletal muscle cells. This general objective had two specific experimental components: (1) the progression of changes in cell morphology, fusion, and patterns of contractile filament organization in muscle cell cultures grown in hollow fibers in the Clinostat were evaluated, with appropriate controls; (2) to initiate experiments in which muscle cells were grown on the surface of microcarrier beads. The ultimate objective of this second portion of the work is to determine if these beads can be rotated in a bioreactor and thereby obtain a more accurate approximation of the effects of simulated microgravity on differentiated muscle cells.

Young, Ronald B.; Moriarity, Debra M.

1989-01-01

112

Flow through a laboratory sediment sample: hydraulic conductivity by computer simulation modeling  

NASA Astrophysics Data System (ADS)

Digitized catscan image of a three dimensional laboratory sediment sample provides a host matrix of size 100^3. The porosity of the sample is 0.282, i.e., below the site percolation threshold of a cubic lattice. Despite a high fraction of sediment barriers, visualizations reveal that the ramified channels of connected pores span across the sample. A coarse grained description is used to model fluid by interacting particles in spirit of classical lattice gas. As in experiments, the source of the fluid is connected at one end of the sample in our computer simulations. The fluid constituents execute their stochastic motion via Metropolis algorithm and flow through the sample with periodic boundary condition across transverse boundaries. From the net flow of fluid, we estimate the flux density and the hydraulic conductivity in steady-state. We also consider pressure bias (H) to investigate the response. Results of transport, flux rate, and distribution of fluid will be presented.

Braithwaite, Edward; Reed, Allen; Seyfarth, Ray; Pandey, Ras; Gettrust, Joe

2006-03-01

113

Carbonatisation of Weathered Peridotites in Laboratory Experiments  

NASA Astrophysics Data System (ADS)

Enhanced in-situ carbonatisation of ultramafic rocks has been proposed as a strategy for a permanent and safe storage of CO2 in order to reduce anthropogenic greenhouse gas emissions (e.g., Kelemen and Matter 2008). This idea emerged from studies of natural examples demonstrating that ultramafic rocks react extensively with CO2 to form ophicarbonates. However, despite their Mg-rich nature, ultramafic rocks are often associated with calcite (CaCO3) rather than magnesite (MgCO3) and dolomite (CaMg(CO3)2). Whether these so-called ophicalcites represent sedimentary or tectonic breccias or are produced during hydrothermal alteration of ultramafic rocks, has been discussed for many years (e.g., Folk and McBride 1976). The view that reactions between hydrothermal fluids and ultramafic rocks can result in the formation of ophicalcite was recently supported by Beinlich et al. (2010), who documented Ca- and CO2-metasomatism and extreme Mg depletion in serpentinised and weathered peridotite clasts from the conglomerates of the Solund basin (SW Norway). This study also suggests that weathering is an important factor for the carbonatisation of ultramafic rocks. We have performed hydrothermal experiments on weathered peridotites in order to better constrain the mechanisms and conditions that trigger Mg-loss from ultramafic rocks and subsequent calcite precipitation. Un-crushed, partly serpentinised and weathered peridotite samples were allowed to react in a Ca-bearing saline solution under CO2 pressure (PCO2: 130-160 bar) at 200°C. We were able to illustrate the textural and chemical evolution during the reaction through a detailed comparison of the solid and fluid samples before and after the experiments. The initial samples showed a typical mesh texture with veins of serpentine surrounding meshes filled either with fresh or weathered olivine. The experimentally treated samples reveal a strongly reacted rim, predominantly composed of calcite, but still showing ghosts of the former mesh texture. Meshes that were initially filled with weathered olivine, were preferred sites of reaction relative to fresh olivine and serpentine. Dissolution of the mesh fillings and subsequent replacement by calcite resulted in Mg- and Si-enrichment in the fluid. The results confirm that hydrothermal alteration of ultramafic rocks may lead to Mg-depletion and ophicalcite formation and, in particular, highlight the role of weathering in enhancing the carbonatisation of peridotites. Our study has potential implications for industrial mineral sequestration of CO2 since weathering is commonly extensive in peridotites. The removal of Mg from the site of carbonatisation would be an undesired effect during CO2 injection into ultramafic rocks, but with a Ca-source available carbonatisation may still be effective. References: Beinlich, A., Austrheim, H., Glody, J., Erambert, M. and Andersen, T.B. (2010), Geochim. Cosmochim. Acta, in press. Folk, R.L. and McBride, E.F. (1976), Geology, 4(6): 327-332. Kelemen, P.B. and Matter, J. (2008), PNAS, 105(45): 17295-17300.

Hövelmann, J.; Austrheim, H.; Beinlich, A.; Munz, I. A.

2010-12-01

114

Design and conduct of a windshear detection flight experiment  

NASA Technical Reports Server (NTRS)

A description is presented of the design and conduct of a series of flight experiments that tested the performance of candidate windshear detection devices. A NASA 737 test aircraft with prototype windshear sensors installed flew numerous low altitude penetrations of microburst windshear conditions. These tests were preceded by extensive preparations including piloted simulations, determination of safe operating conditions, and the development of displays, unique flight test hardware, and procedures.

Lewis, Michael S.; Yenni, Kenneth R.; Verstynen, Harry A.; Person, Lee H.

1992-01-01

115

In Situ Techniques for Monitoring Electrochromism: An Advanced Laboratory Experiment  

ERIC Educational Resources Information Center

This experiment employs current technology to enhance and extend existing lab content. The basic principles of spectroscopic and electroanalytical techniques and their use in determining material properties are covered in some detail in many undergraduate chemistry programs. However, there are limited examples of laboratory experiments with in…

Saricayir, Hakan; Uce, Musa; Koca, Atif

2010-01-01

116

Procedure Manuals for the Comparative Systems Laboratory Experiments.  

ERIC Educational Resources Information Center

The report deals with experiments in testing and evaluation of an information retrieval system within the Comparative Systems Laboratory (CSL). Section I outlines the approach and the general methodology developed in CSL, the operational design of the experiments, the construction and use of the manuals, and the general significance of the…

Saracevic, Tefko, Ed.; Rothenberg, Leslie, Ed.

117

Glycosidation of Methanol with Ribose: An Interdisciplinary Undergraduate Laboratory Experiment  

ERIC Educational Resources Information Center

This exercise provides students hands-on experience with the topics of glycosidation, hemiacetal and acetal formation, proton nuclear magnetic resonance ([superscript 1]H NMR) spectroscopy, and kinetic and thermodynamic product formation. In this laboratory experiment, the methyl acetal of ribose is synthesized, and the kinetic and thermodynamic…

Simon, Erin; Cook, Katie; Pritchard, Meredith R.; Stripe, Wayne; Bruch, Martha; Bendinskas, Kestutis

2010-01-01

118

CONVECTIVE DIFFUSION FIELD MEASUREMENTS COMPARED WITH LABORATORY AND NUMERICAL EXPERIMENTS  

EPA Science Inventory

Some of the more fundamental diffusion parameters measured in the CONDORS convective diffusion field experiment are compared with laboratory experiment and numerical modeling results by means of nondimensionalizations using convective scaling (i.e., mixing depth, z sub i, for len...

119

Does the Lack of Hands-On Experience in a Remotely Delivered Laboratory Course Affect Student Learning?  

ERIC Educational Resources Information Center

Educators question whether performing a laboratory experiment as an observer (non-hands-on), such as conducted in a distance education context, can be as effective a learning tool as personally performing the experiment in a laboratory environment. The present paper investigates this issue by comparing the performance of distance education…

Abdel-Salam, Tarek; Kauffman, Paul J.; Crossman, Gary

2006-01-01

120

Laboratory and in-flight experiments to evaluate 3-D audio display technology  

Microsoft Academic Search

Laboratory and in-flight experiments were conducted to evaluate 3-D audio display technology for cockpit applications. A 3-D audio display generator was developed which digitally encodes naturally occurring direction information onto any audio signal and presents the binaural sound over headphones. The acoustic image is stabilized for head movement by use of an electromagnetic head-tracking device. In the laboratory, a 3-D

Mark Ericson; Richard McKinley; Marion Kibbe; Daniel Francis

1994-01-01

121

Estimating sphagnum peat hydraulic properties from laboratory evaporation experiments  

NASA Astrophysics Data System (ADS)

In ombrotrophic peatlands, the equilibrium between the production and decay of organic matter is principally controlled by the moisture state and its oxic/anoxic conditions in the vadose zone. In order to predict a peatland's fate, it is necessary to describe the hydraulic processes with models correctly. However, no suitable systematic and mechanistic model exists to date. This knowledge gap is attributed to the complexity of peatland ecosystem processes. The reasons for this probably include spatial and temporal heterogeneities, swelling and shrinkage phenomena, hydrophobicity and difficulties in representative sampling. For a valid description of the non-linear processes involved, peat soil hydraulic properties play an intricate part. Their determination requires taking the characteristics mentioned into considered. Our research aims to quantify these characteristics and, eventually, to establish a model in order to numerically simulate the water fluxes in the unsaturated zone. We started with laboratory measurements with which we determined peat soil hydraulic properties. Our study is based on an ombrotrophic peatland site in the Harz Mountains (Germany). Samples were taken over the entire unsaturated part of a Histosol profile. Before the laboratory experiments, samples were frozen, cut to shape and subsequently fully saturated in a vacuum. We used the same sample specimen for the saturated hydraulic conductivity and the simplified evaporation method. Results show that the hydraulic properties rapidly change in the upper-most layers with a step-like change over a small distance, close to the permanently saturated zone. We also show that the swelling and shrinkage is considerable, which means that traditional concepts based on the rigidity of the porous media are not applicable. Furthermore, the results indicate that the frequently used van Genuchten model cannot describe our data very well.

Weber, Tobias K. D.; Durner, Wolfgang

2013-04-01

122

CSI flight experiment projects of the Naval Research Laboratory  

NASA Technical Reports Server (NTRS)

The Naval Research Laboratory (NRL) is involved in an active program of CSI flight experiments. The first CSI flight experiment of the Naval Research Laboratory, the Low Power Atmospheric Compensation Experiment (LACE) dynamics experiment, has successfully measured vibrations of an orbiting satellite with a ground-based laser radar. The observations, made on January 7, 8 and 10, 1991, represent the first ever measurements of this type. In the tests, a narrowband heterodyne CO2 laser radar, operating at a wavelength of 10.6 microns, detected vibration induced differential-Doppler signatures of the LACE satellite. Power spectral densities of forced oscillations and modal frequencies and damping rates of free-damped vibrations were obtained and compared with finite element structural models of the LACE system. Another manifested flight experiment is the Advanced Controls Technology Experiment (ACTEX) designed to demonstrate active and passive damping with piezo-electric (PZT) sensors and actuators. This experiment was developed under the management of the Air Force Phillips Laboratory with integration of the experiment at NRL. It is to ride as a secondary, or 'piggyback,' experiment on a future Navy satellite.

Fisher, Shalom

1993-01-01

123

Developing School Laboratories To Promote the Establishment of Individual Experience Programs. Final Report.  

ERIC Educational Resources Information Center

A project was conducted to promote and develop individual Supervised Agricultural Experience (SAE) programs in Arkansas through the development of laboratories. It was felt that strong SAE programs enhance the instructional portion of agriculture education, serve as a motivational tool, and improve the relations between the local school and…

Valley Springs School District 2, AR.

124

ORGANIC CONTAMINANT DISTRIBUTION IN SEDIMENTS, POLYCHAETES (NEREIS VIRENS) AND THE AMERICAN LOBSTER, HOMARUS AMERICANUS IN A LABORATORY FOOD CHAIN EXPERIMENT  

EPA Science Inventory

A laboratory experiment was conducted to investigate the transfer of organic contaminants from an environmentally contaminated marine sediment through a simple marine food chain. The infaunal polychaete, Nereis virens, was exposed to contaminated sediment collected from the Passa...

125

Disposition of transuranic residues from plutonium isentropic compression experiment (Pu-ice) conducted at Z machine  

SciTech Connect

In 1992, the U.S. Congress passed legislation to discontinue above- and below-ground testing of nuclear weapons. Because of this, the U.S. Department of Energy (DOE) must rely on laboratory experiments and computer-based calculations to verify the reliability of the nation's nuclear stockpile. The Sandia National Laboratories/New Mexico (SNL/NM) Z machine was developed by the DOE to support its science-based approach to stockpile stewardship. SNL/NM researchers also use the Z machine to test radiation effects on various materials in experiments designed to mimic nuclear explosions. Numerous components, parts, and materials have been tested. These experiments use a variety of radionuclides; however, plutonium (Pu) isotopes with greater than ninety-eight percent enrichment are the primary radionuclides used in the experiments designed for stockpile stewardship. In May 2006, SNL/NM received authority that the Z Machine Isentropic Compression Experiments could commence. Los Alamos National Laboratory (LANL) provided the plutonium targets and loaded the target assemblies, which were fabricated by SNL/NM. LANL shipped the loaded assemblies to SNL/NM for Z machine experiments. Three experiments were conducted from May through July 2006. The residues from each experiment, which weighed up to 913 pounds, were metallic and packaged into a respective 55-gallon drum each. Based on a memorandum of understanding between the two laboratories, LANL provides the plutonium samples and the respective radio-isotopic information. SNL/NM conducts the experiments and provides temporary storage for the drums until shipment to LANL for final waste certification for disposal at the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. This paper presents a comprehensive approach for documenting generator knowledge for characterization of waste in cooperation with scientists at the two laboratories and addresses a variety of topics such as material control and accountability, safeguards of material, termination of safeguards for eventual shipment from SNL/NM to LANL, associated approvals from DOE-Carlsbad Field Office, which governs WIPP and various notifications. It portrays a comprehensive approach needed for successful completion of a complex project between two national laboratories.

Goyal, Kapil K [Los Alamos National Laboratory; French, David M [Los Alamos National Laboratory; Humphrey, Betty J [WESTON SOLUTIONS INC.; Gluth, Jeffry [SNL

2010-01-01

126

Controversy surrounding the Experiment conducted to prove the Vortex Theory  

NASA Astrophysics Data System (ADS)

Great controversy surrounds the discovery of the photon acceleration effect. Using the principles of the Vortex Theory, it was theorized that when a photon encounters an electromagnetic field, both the velocity and the frequency of the photon will increase. However, according to contemporary 20^th century science, the effect is believed to be created only by an increase in the wavelength of light. To resolve the controversy, a second experiment must be conducted. The magnets used to conduct the original experiment must be placed in the stream of the laser light of an instrument capable of measuring the speed of light to a value of at least plus or minus 10 meters per second. Since the mathematics reveal that these magnets should increase the speed of light by 4800 mps such an instrument should be capable of resolving the conflict. 1. Konstantin A. Gridnev, Russell G. Moon, Victor V. Vasiliev. Experiment that discovered the Photon Acceleration Effect, Book of abstracts International Symposium on Origin of Matter and Evolution of Galaxies (OMEG05), New Horizon of Nuclear Astrophysics and Cosmology, November 8-11, 2005, University of Tokyo, Tokyo, Japan, p. 77.

Vasiliev, Victor; Moon, Russell

2006-05-01

127

Argumentation in the Chemistry Laboratory: Inquiry and Confirmatory Experiments  

ERIC Educational Resources Information Center

One of the goals of science education is to provide students with the ability to construct arguments--reasoning and thinking critically in a scientific context. Over the years, many studies have been conducted on constructing arguments in science teaching, but only few of them have dealt with studying argumentation in the laboratory. Our research…

Katchevich, Dvora; Hofstein, Avi; Mamlok-Naaman, Rachel

2013-01-01

128

Development of sensorial experiments and their implementation into undergraduate laboratories  

NASA Astrophysics Data System (ADS)

"Visualization" of chemical phenomena often has been limited in the teaching laboratories to the sense of sight. We have developed chemistry experiments that rely on senses other than eyesight to investigate chemical concepts, make quantitative determinations, and familiarize students with chemical techniques traditionally designed using only eyesight. Multi-sensory learning can benefit all students by actively engaging them in learning through stimulation or an alternative way of experiencing a concept or ideas. Perception of events or concepts usually depends on the information from the different sensory systems combined. The use of multi-sensory learning can take advantage of all the senses to reinforce learning as each sense builds toward a more complete experience of scientific data. Research has shown that multi-sensory representations of scientific phenomena is a valuable tool for enhancing understanding of chemistry as well as displacing misconceptions through experience. Multi-sensory experiences have also been shown to enrich memory performance. There are few experiments published which utilize multiple senses in the teaching laboratory. The sensorial experiments chosen were conceptually similar to experiments currently performed in undergraduate laboratories; however students collect different types of data using multi-sensory observations. The experiments themselves were developed by using chemicals that would provide different sensory changes or capitalizing on sensory observations that were typically overlooked or ignored and obtain similar and precise results as in traditional experiments. Minimizing hazards and using safe practices are especially essential in these experiments as students utilize senses traditionally not allowed to be used in the laboratories. These sensorial experiments utilize typical equipment found in the teaching laboratories as well as inexpensive chemicals in order to aid implementation. All experiments are rigorously tested for accuracy and all chemicals examined for safety prior to implementation. The pedagogical objectives were established of to provide the ability to develop and stimulate students' conceptual understanding. The educational assessments of these experiments are are fashioned using the framework chosen (Marzano and Kendall). All the experiments are designed as collaborative, inquiry-based experiments in aims of enhancing the students understanding of the subject and promote critical thinking skills. These experiments use an investigative approach rather than verification methods. Terminology and misconceptions of the experiment were evaluated to prevent misunderstanding or confusion during the experiment. Interventions to address these misconceptions and learning problems associated with the experiment were developed. We have developed the Learning Lab Report, LLR, as an alternative model for the traditional laboratory reports, with the goal of transforming the traditional reports into something more useful for both students and instructors. The educational strategies are employed to develop this format in order to promote students to think critically about the concepts and take an active involvement in learning. From the results of the LLR, all experiments were reviewed and re-written to address any learning problems. The sensorial experiments study several topics usually covered in the first 2 years of the chemistry curriculum (general and organic chemistry courses). The experiments implemented, organic qualitative analysis, esterification kinetics, Le Chatelier equilibrium, thermometric titrations and ASA kinetics, worked effectively as students were able to draw correct conclusions about the concepts from the data obtained. An olfactory titration using the smell of the rutabaga vegetable has been developed and thoroughly tested. The LLR was utilized with the equilibrium, titration and acetyl salicylic acid experiments. The details of the development, implementation of these sensorial experiments and the LLR and student results are discussed.

Bromfield Lee, Deborah Christina

129

On integrating large eddy simulation and laboratory turbulent flow experiments.  

PubMed

Critical issues involved in large eddy simulation (LES) experiments relate to the treatment of unresolved subgrid scale flow features and required initial and boundary condition supergrid scale modelling. The inherently intrusive nature of both LES and laboratory experiments is noted in this context. Flow characterization issues becomes very challenging ones in validation and computational laboratory studies, where potential sources of discrepancies between predictions and measurements need to be clearly evaluated and controlled. A special focus of the discussion is devoted to turbulent initial condition issues. PMID:19531513

Grinstein, Fernando F

2009-07-28

130

An automated tool for three types of saturated hydraulic conductivity laboratory measurements  

SciTech Connect

Acquisition of porous medium hydraulic conductivity in the laboratory is usually time-consuming and costly because of the manual labor associated with the currently available techniques. Lately, there has been increased interest in automating hydraulic conductivity laboratory techniques to reduce analysis time and improve data consistency. A new apparatus is presented that is able to determine hydraulic conductivity values with the falling head, constant head, and constant flux methods in an automated fashion. In addition, the columns are designed forcing water to flow in a nominally one-dimensional manner throughout the porous medium. In this paper, hydraulic conductivity data for standard laboratory sands are presented and compared to results obtained using a standard Tempe cell configuration. Hydraulic conductivity values obtained with the new tool for the laboratory sands are consistent with literature data. For highly permeable sands, the newly obtained hydraulic conductivity values are considerable larger then values acquired using a Tempe cell configuration. The lower conductivity values for the Tempe Cell configuration are primarily the result of insufficient spreading of water in the inlet and outlet reservoirs.

Wietsma, Thomas W.; Oostrom, Martinus; Covert, Matthew A.; Queen, Theresa E.; Fayer, Michael J.

2009-03-01

131

Large-size space laboratory for biological orbit experiments.  

PubMed

The study of space factors on living systems has great interest and long-term experiments during orbital flight will be important tool for increasing our knowledge. Realization of such experiments is limited by constraints of modern space stations. A new technology of large-size space laboratory for biological experiments has been developed on the basis of polymerization techniques. Using this technique there are no limits of form and size of laboratory for a space station that will permit long term experiments on Earth orbit with plants and animals in sufficient volume for creation of closed self-regulating ecological systems. The technology is based on experiments of the behavior of polymer materials in simulated free space conditions during the reaction of polymerization. The influences of space vacuum, sharp temperature changes and space plasma generated by galactic rays and Sun irradiation on chemical reaction were evaluated in their impact on liquid organic materials in laboratory conditions. The results of our study shows, that the chemical reaction is sensitive to such space factors. But we believe that the technology of polymerization could be used for the creation of space biological laboratories in Earth orbit in the near future. PMID:11803970

Kondyurin, A

2001-01-01

132

A self-novelty manipulation of self-focused attention for internet and laboratory experiments.  

PubMed

Conventional manipulations of self-focused attention are poorly suited for Internet experiments and for group-based administration. The authors present a self-novelty manipulation that effectively induces self-awareness for such contexts. In the high self-focus condition, people write about how they differ from their family and friends and from people in general. In the control conditions, people write about neutral topics or do no writing. Three experiments using different measures of self-focus (the situational self-awareness scale, a pronoun selection task, and the private self-consciousness scale) showed that the self-novelty manipulation significantly increased self-focused attention. This effect appeared in Internet-based experiments (Experiment 1) and in laboratory experiments with groups (Experiments 2 and 3). The self-novelty manipulation appears promising for self-awareness research conducted outside of conventional laboratory contexts. PMID:15354698

Silvia, Paul J; Eichstaedt, Jan

2004-05-01

133

Conceptual change in an organic chemistry laboratory: A comparison of computer simulations and traditional laboratory experiments  

NASA Astrophysics Data System (ADS)

This quasi-experimental research study examined the effect of computer simulations and hands-on laboratory experiments in enhancing conceptual understanding and alleviating misconceptions of organic chemistry reaction mechanisms. Subjects were sixty-nine sophomore-level organic chemistry students enrolled in four laboratory sections. Laboratory sections were stratified across instructor and randomly assigned to serve as a control or treatment laboratory. Students in the control group performed all hands-on experiments. Students in the treatment group performed hands-on experiments for the first and last part of the semester but performed computer simulations for a five-week period in the middle of the semester. Prior to treatment, groups were equivalent with respect to academic orientation, motivation, formal reasoning ability, and spatial visualization ability. Fifteen common misconceptions held by beginning organic chemistry students were identified from the Covalent Bonding and Structures Test. At the end of the semester, thirteen of these misconceptions persisted. Molecular geometry was the only category of misconceptions that significantly improved as a result of computer simulations, F(1,58) = 6.309, p = .015. No significant differential change was observed in misconceptions about bond polarity, molecular polarity, intermolecular forces, lattice structures, or the octet rule. Computer simulations were found to result in significantly greater conceptual understanding of organic chemistry reactions on two of the experiments, Stereochemistry, F(1,55) = 6.174, p = .016, and Nucleophilic Substitution, F(1,57) = 6.093, p = .017. The other three experiments, Infrared Spectroscopy, Elimination, and Oxymercuration, did not show a significant differential effect between types of laboratory experiences. No significant differences were observed on long-term retention of concepts. Overall conclusions from the study are that neither computer simulations nor hands-on laboratory experiments are effective in alleviating misconceptions, but that computer simulations can significantly improve conceptual understanding of organic reaction mechanisms.

Gaddis, Barbara A.

2001-12-01

134

A Semi-Batch Reactor Experiment for the Undergraduate Laboratory  

ERIC Educational Resources Information Center

This experiment and analysis offer an economic yet challenging semi-batch reactor experience. Household bleach is pumped at a controlled rate into a batch reactor containing pharmaceutical hydrogen peroxide solution. Batch temperature, product molecular oxygen, and the overall change in solution conductivity are metered. The reactor simulation…

Derevjanik, Mario; Badri, Solmaz; Barat, Robert

2011-01-01

135

Evaporation of J13 water: laboratory experiments and geochemical modeling  

Microsoft Academic Search

We report results from experiments on the evaporative chemical evolution of synthetic J13 water, representative of water from well J13, a common reference water in the Yucca Mountain Project. Data include anion and cation analysis and qualitative mineral identification for a series of open system experiments, with and without crushed tuff present, conducted at sub-boiling temperatures. Ca and Mg precipitated

M. J. Dibley; K. G. Knauss; N. D. Rosenberg

1999-01-01

136

Lava-substrate heat transfer: Laboratory experiments and thermodynamic modeling  

NASA Astrophysics Data System (ADS)

We have performed laboratory experiments and numerical modeling to investigate the heat transfer from a lava flow into various substrate materials, focusing on the effects of the differing thermophysical properties of substrate materials. Initial motivation for this project developed from the desire to understand the loss of solar wind volatiles embedded in lunar regolith deposits that were subsequently covered by a lava flow. The Moon lacks a significant atmosphere and magnetosphere, leaving the surface regolith exposed to bombardment by solar flare and solar wind particles, and by the cosmogenic products of galactic cosmic rays. Preservation of particle-rich regolith deposits may have occurred by the emplacement of an active lava flow on top of the regolith layer, provided the embedded particles survive heating by the lava. During future expeditions to the lunar surface, ancient regolith deposits could be sampled through surface drilling to extract the extra-lunar particles, revealing a history of the solar activity and galactic events not available on the Earth. This project also has important implications for terrestrial lava flows, particularly in the prediction of lava flow hazards. Lava erupted on Earth may be emplaced on various substrates, including solid lava rock, volcanic tephra, sands, soils, etc. The composition, grain size, consolidation, moisture content, etc. of these materials will vary greatly and have different effects on the cooling of the flow. Accounting for specific properties of the substrate could be an important improvement in lava flow models We have performed laboratory experiments in collaboration with the Department of Art and Art History at the University of Hawaii at Manoa in which ~5-6 kg of basalt, collected at Kilauea Volcano, Hawaii, is melted to ~1200 °C. The lava is poured into a device constructed of calcium silicate sheeting that has been filled with a solid or particulate substrate material and embedded with thermocouples. Internal temperatures are monitored by the thermocouple array, while external temperatures are monitored by a Forward Looking Infrared Radiometer (FLIR) video camera. The experimental data thus describe the cooling rates of the system, and reveal the release of latent heat of crystallization within the cooling lava. These experiments have been conducted in conjunction with numerical simulations of the heat transfer from a lava flow into various substrates, to quantify the depth reached by the heat pulse as it penetrates the substrate. Models include material-specific, temperature-dependent thermophysical properties, including thermal conductivity, specific heat capacity, and latent heat of crystallization. We find that particulate materials, such as lunar regolith, sand, and soils will be heated to depths shallower than solid materials. In addition, the particulate materials will act as insulators, shielding the lava flow from basal cooling and maintaining high temperatures in the flow core. These results suggest that lava flows emplaced on a dry particulate terrain will remain above solidus for a longer duration, allowing the lava to flow further than when emplaced on a solid substrate.

Rumpf, M.; Fagents, S. A.; Hamilton, C. W.; Wright, R.; Crawford, I.

2012-12-01

137

Soap from Nutmeg: An Integrated Introductory Organic Chemistry Laboratory Experiment  

NASA Astrophysics Data System (ADS)

The extraction of trimyristin from nutmeg, its purification, and its conversion to a soap (sodium myristate) are described. Concepts such as the isolation of a natural product, recrystallization, identification of a solid, solubility, acidity and basicity, and organic reaction can be presented to students using integrated experiments in an introductory experimental chemistry laboratory. These experiments can easily be done in three class periods of four hours.

See Letter re: this article.

de Mattos, Marcio C. S.; Nicodem, David E.

2002-01-01

138

Effective Laboratory Experiences for Students with Disabilities: The Role of a Student Laboratory Assistant  

NASA Astrophysics Data System (ADS)

Two separate experiences with students whose disabilities significantly limited the number of laboratory activities they could accomplish independently has given us a general experience base for determining successful strategies for accommodating students facing these situatiuons. For a student who had substantially limited physical mobility and for a student who had no visual ability, employing a student laboratory assistant allowed the students with disabilities to have a productive and positive laboratory experience. One of the priorities in these situations should be to avoid depersonalizing the student with a disability. Interactions with the instructor and with other students should focus on the disabled student rather than the student laboratory assistant who may be carrying out specific tasks. One of the most crucial aspects of a successful project is the selection of a laboratory assistant who has excellent interpersonal skills and who will add his or her creativity to that of the student with a disability to meet unforeseen challenges. Other considerations are discussed, such as the importance of advance notification that a disabled student has enrolled in a course as well as factors that should contribute to choosing an optimum laboratory station for each situation.

Pence, Laura E.; Workman, Harry J.; Riecke, Pauline

2003-03-01

139

Enhancing the Laboratory Experience Using Peer Evaluation of Group Laboratory Reports in a Fluid Mechanics Course  

NSDL National Science Digital Library

Peer evaluation of laboratory reports has been found to be a valuable tool in a junior level fluid mechanics laboratory. Readily available equipment makes it possible to have separate experiments investigating applications of the mechanical energy equation to nearly ideal venturis, an array of flow meters, an array of various fittings, and a single pipe. Having each group of students carry out all four experiments and report on the results can lead to equipment utilization conflicts, student exhaustion, and a lack of attention to detail in the final laboratory reports. In spring of 2006 the author decided to streamline this segment of the laboratory by having each laboratory group (typically teams of four students) perform and report on only two of the four experiments listed above. They were, however, required to provide peer evaluation of the reports of another student group for the experiments which they did not personally carry out. These peer evaluations were then compared with the instructors evaluations of the same reports and feedback was given to both the group being evaluated and the evaluators. The expected benefits of this change were reduced stress on the students, increased student understanding of and appreciation for the laboratory report evaluation criteria, broader understanding of frictional losses in pipes and devices, and better utilization of the available laboratory equipment. Results from both spring 2006 and 2007 confirmed that the students did an excellent job of assessing the reports submitted by other groups, and exam performance confirmed their understanding of the processes involved in experiments which they evaluated but did not carry out. However, student performance on future laboratory reports did not improve significantly, as had been anticipated. In other words, although students could clearly identify the strengths and the weaknesses of laboratory reports written by others, this did not translate directly into an improvement in their own reports. Future efforts will focus on using this experience not only to reduce student work load and enhance learning, but also on using the experience to help students improve their own reporting skills.

Shaw, David

2012-05-29

140

The software engineering laboratory: an operational software experience factory  

Microsoft Academic Search

For 15 years, the Software Engineering Laboratory (SEL) has been carrying out studies and experiments for the purpose of understanding, assessing, and improving software and softwrne processes within a production software development environment at the National Aeronautics and Space Administration\\/Goddard Space Flight Center (NASA\\/GSFC). The SEL comprises three major organizations: ? NASA\\/GSFC, Flight Dynamics Division

Victor R. Basili; Gianluigi Caldiera; Frank E. McGarry; Rose Pajerski; Gerald T. Page; Sharon Waligora

1992-01-01

141

An Enzyme Kinetics Experiment for the Undergraduate Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

An experiment using [superscript 1]H NMR spectroscopy to observe the kinetics of the acylase 1-catalyzed hydrolysis of "N"-acetyl-DL-methionine has been developed for the organic laboratory. The L-enantiomer of the reactant is hydrolyzed completely in less than 2 h, and [superscript 1]H NMR spectroscopic data from a single sample can be worked up…

Olsen, Robert J.; Olsen, Julie A.; Giles, Greta A.

2010-01-01

142

Differentiating Biochemistry Course Laboratories Based on Student Experience  

ERIC Educational Resources Information Center

Content and emphases in undergraduate biochemistry courses can be readily tailored to accommodate the standards of the department in which they are housed, as well as the backgrounds of the students in the courses. A more challenging issue is how to construct laboratory experiences for a class with both chemistry majors, who usually have little or…

Jakubowski, Henry V.

2011-01-01

143

Raising Environmental Awareness through Applied Biochemistry Laboratory Experiments  

ERIC Educational Resources Information Center

Our environment is under constant pressure and threat from various sources of pollution. Science students, in particular chemistry students, must not only be made aware of these issues, but also be taught that chemistry (and science) can provide solutions to such real-life issues. To this end, a newly developed biochemistry laboratory experiment…

Salman Ashraf, S.

2013-01-01

144

Lidocaine Metabolism and Toxicity: A Laboratory Experiment for Dental Students.  

ERIC Educational Resources Information Center

A laboratory exercise for dental students is presented using a toxic dose of lidocaine in place of an anesthetic dose of pentobarbital. The use of lidocaine demonstrates its toxic and lethal actions and increases the relevance of the experience for dental students. (Author/MLW)

Kusek, J. C.

1980-01-01

145

Laboratory Experiment in Semiconductor Surface-Field Effects  

ERIC Educational Resources Information Center

A laboratory instructional program involving metal-insulator-semiconductor (MIS) devices is described. In the first of a two-part experiment, students become familiar with the important parameters of a simple MIS device and learn measurement techniques; in the second part, device fabrication procedures are learned. (DT)

Goodman, F. R.; And Others

1974-01-01

146

Development of Sensorial Experiments and Their Implementation into Undergraduate Laboratories  

ERIC Educational Resources Information Center

"Visualization" of chemical phenomena often has been limited in the teaching laboratories to the sense of sight. We have developed chemistry experiments that rely on senses other than eyesight to investigate chemical concepts, make quantitative determinations, and familiarize students with chemical techniques traditionally designed using only…

Bromfield Lee, Deborah Christina

2009-01-01

147

Raising environmental awareness through applied biochemistry laboratory experiments.  

PubMed

Our environment is under constant pressure and threat from various sources of pollution. Science students, in particular chemistry students, must not only be made aware of these issues, but also be taught that chemistry (and science) can provide solutions to such real-life issues. To this end, a newly developed biochemistry laboratory experiment is described that guides students to learn about the applicability of peroxidase enzymes to degrade organic dyes (as model pollutants) in simulated waste water. In addition to showing how enzymes can potentially be used for waste water remediation, various factors than can affect enzyme-based reactions such as pH, temperature, concentration of substrates/enzymes, and denaturants can also be tested. This "applied biotechnology" experiment was successfully implemented in an undergraduate biochemistry laboratory course to enhance students' learning of environmental issues as well important biochemistry concepts. Student survey confirmed that this laboratory experiment was successful in achieving the objectives of raising environmental awareness in students and illustrating the usefulness of chemistry in solving real-life problems. This experiment can be easily adopted in an introductory biochemistry laboratory course and taught as an inquiry-guided exercise. PMID:24078356

Salman Ashraf, S

2013-01-01

148

Hyporheic exchange with heterogeneous streambeds: Laboratory experiments and modeling  

Microsoft Academic Search

Hyporheic exchange is generally analyzed with the assumption of a homogeneous hyporheic zone. In reality, streambed sediments have a heterogeneous structure, and this natural heterogeneity produces spatially variable interfacial fluxes and complex hyporheic exchange patterns. To assess the basic effects of sediment structure on hyporheic exchange, we performed salt and dye injection experiments in a recirculating laboratory flume with two

Mashfiqus Salehin; Aaron I. Packman; Matthew Paradis

2004-01-01

149

Propulsion Integrated Vehicle Health Management Technology Experiment (PITEX) Conducted  

NASA Technical Reports Server (NTRS)

The Propulsion Integrated Vehicle Health Management (IVHM) Technology Experiment (PITEX) is a continuing NASA effort being conducted cooperatively by the NASA Glenn Research Center, the NASA Ames Research Center, and the NASA Kennedy Space Center. It was a key element of a Space Launch Initiative risk-reduction task performed by the Northrop Grumman Corporation in El Segundo, California. PITEX's main objectives are the continued maturation of diagnostic technologies that are relevant to second generation reusable launch vehicle (RLV) subsystems and the assessment of the real-time performance of the PITEX diagnostic solution. The PITEX effort has considerable legacy in the NASA IVHM Technology Experiment for X-vehicles (NITEX) that was selected to fly on the X-34 subscale RLV that was being developed by Orbital Sciences Corporation. NITEX, funded through the Future-X Program Office, was to advance the technology-readiness level of selected IVHM technologies within a flight environment and to begin the transition of these technologies from experimental status into RLV baseline designs. The experiment was to perform realtime fault detection and isolation and suggest potential recovery actions for the X-34 main propulsion system (MPS) during all mission phases by using a combination of system-level analysis and detailed diagnostic algorithms.

Maul, William A.; Chicatelli, Amy K.; Fulton, Christopher E.

2004-01-01

150

Modeling of Thermal-Hydrological-Chemical Laboratory Experiments  

SciTech Connect

The emplacement of heat-generating nuclear waste in the potential geologic repository at Yucca Mountain, Nevada, will result in enhanced water-rock interaction around the emplacement drifts. Water present in the matrix and fractures of the rock around the drift may vaporize and migrate via fractures to cooler regions where condensation would occur. The condensate would react with the surrounding rock, resulting in mineral dissolution. Mineralized water flowing under gravity back towards the heat zone would boil, depositing the dissolved minerals. Such mineral deposition would reduce porosity and permeability above the repository, thus altering the flow paths of percolating water. The objective of this research is to use coupled thermal-hydrological-chemical (THC) models to simulate previously conducted laboratory experiments involving tuff dissolution and mineral precipitation in a boiling, unsaturated fracture. Numerical simulations of tuff dissolution and fracture plugging were performed using a modified version of the TOUGHREACT code developed at LBNL by T. Xu and K. Pruess. The models consider the transport of heat, water, gas and dissolved constituents, reactions between gas, mineral and aqueous phases, and the coupling of porosity and permeability to mineral dissolution and precipitation. The model dimensions and initial fluid chemistry, rock mineralogy, permeability, and porosity were defined using the experimental conditions. A 1-D plug-flow model was used to simulate dissolution resulting from reaction between deionized water and crushed ash flow tuff. A 2-D model was developed to simulate the flow of mineralized water through a planar fracture within a block of ash flow tuff where boiling conditions led to mineral precipitation. Matrix blocks were assigned zero permeability to confine fluid flow to the fracture, and permeability changes in the fracture were specified using the porosity cubic law relationship.

P. F. Dobson; T. J. Kneafsey; E. L. Sonnenthal; Nicolas Spycher

2001-05-31

151

Multiuser Droplet Combustion Apparatus Developed to Conduct Combustion Experiments  

NASA Technical Reports Server (NTRS)

A major portion of the energy produced in the world today comes from the combustion or burning of liquid hydrocarbon fuels in the form of droplets. However, despite vigorous scientific examinations for over a century, researchers still lack a full understanding of many fundamental combustion processes of liquid fuels. Understanding how these fuel droplets ignite, spread, and extinguish themselves will help us develop more efficient ways of energy production and propulsion, as well as help us deal better with the problems of combustion-generated pollution and fire hazards associated with liquid combustibles. The ability to conduct more controlled experiments in space, without the complication of gravity, provides scientists with an opportunity to examine these complicated processes closely. The Multiuser Droplet Combustion Apparatus (MDCA) supports this continued research under microgravity conditions. The objectives are to improve understanding of fundamental droplet phenomena affected by gravity, to use research results to advance droplet combustion science and technology on Earth, and to address issues of fire hazards associated with liquid combustibles on Earth and in space. MDCA is a multiuser facility designed to accommodate different combustion science experiments. The modular approach permits the on-orbit replacement of droplet combustion principal investigator experiments such as different fuels, droplet-dispensing needles, and droplet-tethering mechanisms. Large components such as the avionics, diagnostics, and base-plate remain on the International Space Station to reduce the launch mass of new experiments. MDCA is also designed to operate in concert with ground systems on Earth to minimize the involvement of the crew during orbit.

Myhre, Craig A.

2001-01-01

152

Experiences and prospects of nuclear astrophysics in underground laboratories  

NASA Astrophysics Data System (ADS)

Impressive progress has been made in the course the last decades in understanding astrophysical objects. Increasing precision of nuclear physics data has contributed significantly to this success, but now a better understanding of several important findings is frequently limited by uncertainties related to the available nuclear physics data. Consequently it is desirable to improve significantly the quality of these data. An important step towards higher precision is an excellent signal to background ratio of the data. Placing an accelerator facility inside an underground laboratory reducing the cosmic ray induced background by six orders of magnitude is a powerful method to reach this goal, even though careful reduction of environmental and beam induced background must still be considered. Experience in the field of underground nuclear astrophysics has been gained since 20 years due to the pioneering work of the LUNA Collaboration (Laboratory for Underground Nuclear Astrophysics) operating inside the underground laboratories of the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. Based on the success of this work presently also several other projects for underground laboratories dedicated to nuclear astrophysics are being pursued worldwide. This contribution will give a survey of the past experience in underground nuclear astrophysics as well as an outlook on future developments.

Junker, M.

2014-05-01

153

Designing Online Resources in Preparation for Authentic Laboratory Experiences  

PubMed Central

Professional development for science teachers can be benefited through active learning in science laboratories. However, how online training materials can be used to complement traditional laboratory training is less understood. This paper explores the design of online training modules to teach molecular biology and user perception of those modules that were part of an intensive molecular biology “boot camp” targeting high school biology teachers in the State of Hawaii. The John A. Burns School of Medicine at the University of Hawaii had an opportunity to design and develop professional development that prepares science teachers with an introduction of skills, techniques, and applications for their students to conduct medical research in a laboratory setting. A group of 29 experienced teachers shared their opinions of the online materials and reported on how they used the online materials in their learning process or teaching.

Boulay, Rachel; Parisky, Alex; Leong, Peter

2013-01-01

154

Electrical conductivity of pyroxene which contains trivalent cations: Laboratory measurements and the lunar temperature profile  

Microsoft Academic Search

Three natural orthopyroxene single crystals, measured in the laboratory over the temperature range 850°⁻⁻¹²°°sup 0\\/C, are more than 1\\/2 order of magnitude more electrically conducting than previously measured crystals. Small concentrations (1--2%) of AlâOâ and CrâOâ present in these crystals may be responsible for their relatively high conductivity. Such pyroxenes, which contain trivalent elements, are more representative of pyroxenes expected

J. S. Huebner; A. Duba; L. B. Wiggins

1979-01-01

155

Infrasound Generated by Strombolian Eruptions - Insights from Laboratory Experiments  

NASA Astrophysics Data System (ADS)

In recent years infrasonic monitoring at volcanoes has become an increasingly common tool. Much of the current work on interpreting volcano infrasound has concentrated on Strombolian eruptions, and several mechanisms have been suggested for the sound produced at these eruptions. However, the precise mechanisms at the vent need to be identified and understood if infrasound recorded in the field is to be used to infer conditions in the volcanic system. In this work, laboratory experiments using audio recordings coupled with high speed video footage have been conducted to gain a deeper understanding of these sounds. A simplified analogue model is used as an analogy for a Strombolian eruption: an air bubble rises through a tank containing a viscous Newtonian liquid (golden syrup) and bursts at the surface. Although the experimental set-up is simple and idealized, it allows control of physical properties and measurement of the processes observed far more accurately than would be possible in the field. Physical parameters which may control the form of the acoustic wave produced, such as liquid viscosity (achieved by dilution of pure golden syrup with water) and bubble volume are investigated. Initial results show that the onset of the main part of the acoustic waveform occurs concurrently with the onset of bubble rupture. Trends in the amplitude and frequency of the acoustic waveform, as well as bubble rupture speed are seen as the liquid viscosity varied. A number of candidate mechanisms for the production of sound during the experiments have been investigated, and synthetic waveforms compared to experimental data. These include the flow of gas through a growing hole from a pressurised reservoir (the bubble), and the mass flux due to the collapse of the bubble film. Importantly it has been shown that even in this very simple case - the sound produced by the bursting of a hemispherical bubble formed at the surface of a viscous liquid - is not as simple as some theories might suggest. For example, the classic balloon burst equation (? = 2r/c where ? is waveform period, r is bubble radius and c is the speed of sound in air) over predicts the frequency of the waveform produced by an order of magnitude when compared to experimental data.

Dabrowa, A.; Phillips, J. C.; Rust, A.; Green, D. N.

2010-12-01

156

21 CFR 101.108 - Temporary exemptions for purposes of conducting authorized food labeling experiments.  

Code of Federal Regulations, 2010 CFR

...of conducting authorized food labeling experiments. 101.108 Section 101.108 ...of conducting authorized food labeling experiments. (a) The food industry is encouraged to experiment voluntarily, under controlled...

2010-04-01

157

21 CFR 101.108 - Temporary exemptions for purposes of conducting authorized food labeling experiments.  

Code of Federal Regulations, 2010 CFR

...of conducting authorized food labeling experiments. 101.108 Section 101.108 ...of conducting authorized food labeling experiments. (a) The food industry is encouraged to experiment voluntarily, under controlled...

2009-04-01

158

Analysis of Thermal-Conductivity Measurement Data from International Comparison of National Laboratories  

NASA Astrophysics Data System (ADS)

For the first time under the auspices of the Bureau International des Poids et Mesures (BIPM), seven national metrology institutes (NMIs) participated in an international interlaboratory comparison on thermal-conductivity measurements by the guarded hot-plate method. Measurements were conducted successively by all participants on the same set of specimens of insulating materials (mineral wool and expanded polystyrene) at temperatures ranging from 10 °C to 40 °C, according to the International Standard ISO 8302. This protocol aims to minimize issues of material variability by circulating the same pairs of specimens among the laboratories following the strict format of a round-robin test program. This comparison is a pilot study which is intended as a first stage for future key comparisons between NMIs. The descriptive analysis of obtained results shows good agreement between laboratories for the mineral wool (MW) specimens and the thicker specimens of expanded polystyrene (EPS), with relative deviations within the uncertainties of measurement. A positive drift of thermal-conductivity values, which has appeared progressively during the comparison process, seems to be correlated with the size of the metering area of the guarded hot plates used. A statistical analysis was applied to repeated thermal-conductivity measurements at 23 °C, to identify anomalous and outlying data, to assess the within- and between-laboratory variability, and to evaluate the participant laboratories' performance.

Hay, B.; Zarr, R.; Stacey, C.; Lira-Cortes, L.; Hammerschmidt, U.; Sokolov, N.; Zhang, J.; Filtz, J.-R.; Fleurence, N.

2013-05-01

159

Meta-Analytic Synthesis of Studies Conducted at Marzano Research Laboratory on Instructional Strategies  

ERIC Educational Resources Information Center

This is a summary of 300 plus studies from Marzano Research Laboratory (MRL) on instructional strategies. This report synthesizes a series of action research projects conducted between the fall of 2004 and the spring of 2009. The data used for analysis can be found in MRL's Action Research Meta-Analysis Database. Appended are: (1) Instructions for…

Haystead, Mark W.; Marzano, Robert J.

2009-01-01

160

Considerations regarding appropriate sample size for conducting ferret transmission experiments.  

PubMed

Evaluation of: Nishiura H, Yen H-L, Cowling BJ. Sample size considerations for one-to-one animal transmission studies of the influenza A viruses. PLoS ONE 8(1), e55358 (2013). There is an urgent need to model in a laboratory setting the capacity of wild-type influenza viruses to transmit between mammals, to determine the molecular determinants and identify biological properties that confer influenza virus transmissibility, and to explore both pharmaceutical and nonpharmaceutical methods to inhibit virus transmission. Owing to its close physiologic match to humans, researchers typically utilize the ferret to measure influenza virus transmissibility. Nishiura et al. highlight the dilemma facing researchers utilizing the ferret transmission model: how to provide high-quality data to guide public health efforts, while ensuring the ethical use of animals in limited-size, individual, one-to-one transmission experiments. However, the responsible interpretation of data generated using this model can overcome this potential limitation. A closer examination of previously published studies utilizing this model as it is currently employed reveals that the 'sample size' of these studies is not always as small as it may appear. PMID:23902143

Belser, Jessica A; Maines, Taronna R; Katz, Jacqueline M; Tumpey, Terrence M

2013-08-01

161

Scientific equity: experiments in laboratory education in Ghana.  

PubMed

During the 1960s the Ministry of Education in Ghana created a network of school laboratories to increase scientific literacy among young citizens. The ministry stocked these "Science Centres" with imported beakers, Bunsen burners, and books. Education officials and university scientists worked with teachers to create lesson plans on water, air, plants, and other topics. The government hoped that scientifically minded schoolchildren would be better prepared to staff the industries of the future. The adoption of laboratory norms represented a desire for scientific equity, rather than a condition of cultural mimicry. Interviews with ministry officials and science educators, alongside letters and reports, indicate how students and teachers appropriated the laboratories in the small West African nation. Their experiences in mobilizing resources from across Ghana and around the world provide a metaphor for ongoing efforts to establish access to scientific goods in Africa. PMID:24783491

Osseo-Asare, Abena Dove

2013-12-01

162

Brittle fracture in dry snow: Laboratory experiments and numerical simulations  

NASA Astrophysics Data System (ADS)

Brittle fracture of snow occurs at high strain rates and is the relevant deformation in the formation process of dry snow slab avalanches. The evolution of cracks in snow until fracture and how its microstructure governs this process is still poorly known. To this end, we make laboratory tensile tests with cm sized samples of homogeneous snow at high strain rates until the samples fractured. X-ray micro computertomography is used to obtain the undestroyed 3D microstructure of each sample tested. The tomography data can be used as geometric input in finite element simulations of tensile tests. We want to assess if numerical experiments are able to reproduce snow's fracture behavior as observed in laboratory experiments. If numerical tests could be used to test also the most fragile snow as found e.g. in weak layers, this method based on tomography data would provide a large potential to gain insight into the role of microstructure in brittle fracture processes.

Köchle, Bernadette; Schneebeli, Martin

2014-05-01

163

An Introductory Laboratory Exercise on Solution Preparation: A Rewarding Experience  

NASA Astrophysics Data System (ADS)

This exercise provides beginning students a firsthand experience in solution preparation. It can be completed within two hours. The format of the student handout promotes active learning in the laboratory by having text and questions interspersed among laboratory procedures. This exercise has been used successfully in various introductory courses I have taught for more than 14 years. Factors contributing to its effectiveness include (i) students are motivated to prepare solutions for the fascinating Briggs-Rauscher (BR) oscillation reaction; (ii) the exercise involves a variety of situations commonly encountered in solution preparation; (iii) the challenge of demonstrating the BR reaction seems to be at the appropriate level for beginning students, and meeting the challenge is a rewarding experience and serves as a measure of success in solution preparation; (iv) the exercise lends itself to further take-home studies suitable for different types of introductory chemistry courses.

Wang, M. Rachel

2000-02-01

164

Equipment qualification testing evaluation experiences at Sandia National Laboratories  

SciTech Connect

The USNRC has sponsored a number of programs at Sandia National Laboratories specifically addressing safety-related equipment qualification. The most visible of these programs has been the Qualification Testing Evaluation (QTE) program. Other relevant programs have included the Equipment Qualification Methodology Research Test program (CAP). Over a ten year period these programs have collectively tested numerous types of safety-related equipment. Some insights and conclusions extracted from these testing experiences are summarized in this report.

Bustard, L.D.; Wyant, F.J.; Bonzon, L.L.; Gillen, K.T.

1986-01-01

165

Laboratory Flume Experiment with a Coded Structured Light System  

NASA Astrophysics Data System (ADS)

The topography of inland deltas is influenced chiefly by the water-sediment balance in distributary channels and local evaporation and seepage rates. In a previous study, a reduced complexity model has been applied to simulate the process of inland delta formation. Results have been compared with the Okavango Delta, Botswana and with a laboratory experiment. Both in the macro scale and the micro scale cases, high quality digital elevation models (DEM) are essential. This work elaborates the laboratory experiment where an artificial inland delta is generated on laboratory scale and its topography is measured using a Breuckmann 3D scanner. The space-time evolution of the inland delta is monitored in the consecutive DEM layers. Regarding the 1.0m x 1.0m x 0.3m size of the working area, better than 100 micron precision is achieved which gives a relative precision of 1/10 000. The entire 3D modelling workflow is presented in terms of scanning, co-registration, surface generation, editing, and visualization steps. The co-registered high resolution topographic data allows us to analyse the stratigraphy patterns of the experiment and gain quantitative insight into the spatio-temporal evolution of the delta formation process.

Akca, D.; Seybold, H.

2012-07-01

166

Electrothermal Fluid Manipulation of High-Conductivity Samples for Laboratory Automation Applications  

PubMed Central

Electrothermal flow is a promising technique in microfluidic manipulation toward laboratory automation applications, such as clinical diagnostics and high throughput drug screening. Despite the potential of electrothermal flow in biomedical applications, relative little is known about electrothermal manipulation of highly conductive samples, such as physiological fluids and buffer solutions. In this study, the characteristics and challenges of electrothermal manipulation of fluid samples with different conductivities were investigated systematically. Electrothermal flow was shown to create fluid motion for samples with a wide range of conductivity when the driving frequency was above 100 kHz. For samples with low conductivities (below 1 S/m), the characteristics of the electrothermal fluid motions were in quantitative agreement with the theory. For samples with high conductivities (above 1 S/m), the fluid motion appeared to deviate from the model as a result of potential electrochemical reactions and other electrothermal effects. These effects should be taken into consideration for electrothermal manipulation of biological samples with high conductivities. This study will provide insights in designing microfluidic devices for electrokinetic manipulation of biological samples toward laboratory automation applications in the future.

Sin, Mandy L. Y.; Gau, Vincent; Liao, Joseph C.; Wong, Pak Kin

2010-01-01

167

Ground-based laboratory atomic oxygen calibration experiments  

NASA Astrophysics Data System (ADS)

Existing devices and analysis techniques for the monitoring of space and laboratory simulated Atomic Oxygen (AO) environments have been investigated and improved to enable more accurate and reliable measurement and calibration of AO flux and fluences than previously possible. This research was based on experimental work carried out in a ground based AO facility designed to simulate the low Earth orbit (LEO) AO space environment, an environment which contributes significantly to the degradation of spacecraft materials. Three types of AO measuring device, referred to as 'silver film', 'bulk polymer mass loss' and 'polymer overlay' devices, were used in the experiments and were based on the following principles for detection of AO, respectively: (1) The electrical resistivity characteristics of oxidising, thin silver films. (2) The mass loss of bulk polymeric materials. (3) The combination of both the above phenomena. In calibrating the responses of these devices upon exposure to AO, it was necessary to improve an existing technique to establish reference measurements of AO fluences based on the mass loss of the polymeric material 'Kapton-H'. Experiments showed that the most significant disturbance factor affecting accurate measurements of mass loss was atmospheric humidity, which was found to be responsible for a disturbance of 0.012(±0.002)mg per percent change in atmospheric humidity level for the particular samples used in this research. Experiments also revealed a novel technique which indicated the relative stability of conditions within a simulated AO environment by the ratio of mass losses of a set of polymeric test samples, including polyethylene, polytetrafluoroethylene and Kapton-H, described as a 'signature analysis technique'. Interactions occurring between AO and a variety of polyethylene related polymeric materials were shown to be influenced by the methods used to manufacture and process the polymers. This influence has been related to changes in polymeric material density and crystallinity. In addition, the limitations in protecting a polymeric material from AO erosion by insertion of fluorine into the side-chain group chemistry has been indicated. Of most significance to the development of polymer overlay devices was the discovery that the overlay material AO erosion yield was dependent upon the rate at which the polymer overlay material was sputter deposited. These devices were also shown to detect AO fluences that were linearly dependent upon the initial thickness of the overlay material up to certain thicknesses, beyond which the effects of overlay porosity or fracturing weakened the linear relationship. A novel method for analysing silver film device electrical resistances under AO exposure has been developed from a combination of existing fundamental theories concerning the electrical resistivity phenomena in thin metallic films. Validation of this analysis method revealed that experimental silver film data were consistently in disagreement with the existing theories due to a factor influencing the conduction electron mean free path length in the silver films. Final validation of this analysis technique was performed by comparing results derived from the same set of experimental silver film device data using the new technique and an example of a previous technique. It was confirmed that the novel analysis technique produced far more consistent values for the oxidation yield of silver, 3/pm0.5×10-24cm3.atom-1, than the previously used technique, 6/pm3×10- 24cm3.atom-1. The novel analysis technique has been demonstrated to be theoretically more accurate for the analysis of silver film resistance data than any previously applied theories.

Matcham, Jeremy Stephen

1998-12-01

168

Definition of experiments and instruments for a communication/navigation research laboratory. Volume 4: Programmatics  

NASA Technical Reports Server (NTRS)

Details are provided for scheduling, cost estimates, and support research and technology requirements for a space shuttle supported manned research laboratory to conduct selected communication and navigation experiments. A summary of the candidate program and its time phasing is included, as well as photographs of the 1/20 scale model of the shuttle supported Early Comm/Nav Research Lab showing the baseline, in-bay arrangement and the out-of-bay configuration.

1972-01-01

169

Application of maximum entropy optimal projection design synthesis to the NASA Spacecraft Control Laboratory Experiment (SCOLE)  

NASA Technical Reports Server (NTRS)

The scope of this study covered steady-state, continuous-time vibration control under disturbances applied to the Space Shuttle and continuous-time models of actuators, sensors, and disturbances. Focus was on a clear illustration of the methodology, therefore sensor/actuator dynamics were initially ignored, and a finite element model of the NASA Spacecraft Control Laboratory Experiment (SCOLE) was conducted, including products of inertia and offset of reflector CM from the mast tip.

Hyland, Dave; Davis, Larry

1984-01-01

170

Georgia Teachers in Academic Laboratories: Research Experiences in the Geosciences  

NASA Astrophysics Data System (ADS)

The Georgia Intern-Fellowships for Teachers (GIFT) is a collaborative effort designed to enhance mathematics and science experiences of Georgia teachers and their students through summer research internships for teachers. By offering business, industry, public science institute and research summer fellowships to teachers, GIFT provides educators with first-hand exposure to the skills and knowledge necessary for the preparation of our future workforce. Since 1991, GIFT has placed middle and high school mathematics, science and technology teachers in over 1000 positions throughout the state. In these fellowships, teachers are involved in cutting edge scientific and engineering research, data analysis, curriculum development and real-world inquiry and problem solving, and create Action Plans to assist them in translating the experience into changed classroom practice. Since 2004, an increasing number of high school students have worked with their teachers in research laboratories. The GIFT program places an average of 75 teachers per summer into internship positions. In the summer of 2005, 83 teachers worked in corporate and research environments throughout the state of Georgia and six of these positions involved authentic research in geoscience related departments at the Georgia Institute of Technology, including aerospace engineering and the earth and atmospheric sciences laboratories. This presentation will review the history and the structure of the program including the support system for teachers and mentors as well as the emphasis on inquiry based learning strategies. The focus of the presentation will be a comparison of two placement models of the teachers placed in geoscience research laboratories: middle school earth science teachers placed in a 6 week research experience and high school teachers placed in 7 week internships with teams of 3 high school students. The presentation will include interviews with faculty to determine the value of these experiences to the scientific community and interviews/classroom observations of teachers to determine the transfer of knowledge from the teacher to the students through the implementation of their Action Plans into their classroom.

Barrett, D.

2005-12-01

171

Analysis of Microgravity Experiments Conducted on the Apollo Spacecraft  

NASA Technical Reports Server (NTRS)

This Technical Memorandum (TM) discusses the microgravity experiments carried out during the later missions of the Apollo program. Microgravity experiments took place during the Apollo 14, 16, and 17 missions and consisted of four experiments in various materials processing concentrations with two of the four experiments taking place over the course of two missions. Experiments consist of composite casting, electrophoresis, heat flow and convection, and liquid transfer. This TM discusses the background, the workup, execution, and results of each experiment. In addition, the historical significance of each experiment to future applications/NASA programs is discussed.

Sharpe, R. J.; Wright, M. D.

2009-01-01

172

Lunar temperature and global heat flux from laboratory electrical conductivity and lunar magnetometer data  

NASA Technical Reports Server (NTRS)

Three-layer monotonic electrical conductivity models for the lunar interior to a depth of 600 km are used in conjunction with laboratory measurements of the electrical conductivity of olivine and pyroxene to estimate a temperature-depth profile. The temperatures calculated for depths of 400-600 km are consistent with attenuation of the seismic shear wave. The temperature calculated at a depth of 100-250 km yields a heat flow that is in good agreement with the directly measured lunar heat flow. The temperature, however, is sufficiently close to melting that mascon anisostasy would not be maintained. Thus a better conductor is required at this depth.

Sonett, C. P.; Duba, A.

1975-01-01

173

Constraining PCP Violating Varying Alpha Theory through Laboratory Experiments  

SciTech Connect

In this report we have studied the implication of a parity and charge-parity (PCP) violating interaction in varying alpha theory. Due to this interaction, the state of photon polarization can change when it passes through a strong background magnetic field. We have calculated the optical rotation and ellipticity of the plane of polarization of an electromagnetic wave and tested our results against different laboratory experiments. Our model contains a PCP violating parameter {beta} and a scale of alpha variation {omega}. By analyzing the laboratory experimental data, we found the most stringent constraints on our model parameters to be 1 {le} {omega} {le} 10{sup 13} GeV{sup 2} and -0.5 {le} {beta} {le} 0.5. We also found that with the existing experimental input parameters it is very difficult to detect the ellipticity in the near future.

Maity, Debaprasad; /NCTS, Taipei /Taiwan, Natl. Taiwan U.; Chen, Pisin; /NCTS, Taipei /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC

2012-06-06

174

The spacecraft control laboratory experiment optical attitude measurement system  

NASA Technical Reports Server (NTRS)

A stereo camera tracking system was developed to provide a near real-time measure of the position and attitude of the Spacecraft COntrol Laboratory Experiment (SCOLE). The SCOLE is a mockup of the shuttle-like vehicle with an attached flexible mast and (simulated) antenna, and was designed to provide a laboratory environment for the verification and testing of control laws for large flexible spacecraft. Actuators and sensors located on the shuttle and antenna sense the states of the spacecraft and allow the position and attitude to be controlled. The stereo camera tracking system which was developed consists of two position sensitive detector cameras which sense the locations of small infrared LEDs attached to the surface of the shuttle. Information on shuttle position and attitude is provided in six degrees-of-freedom. The design of this optical system, calibration, and tracking algorithm are described. The performance of the system is evaluated for yaw only.

Welch, Sharon S.; Montgomery, Raymond C.; Barsky, Michael F.

1991-01-01

175

PUREX environmental radiological surveillance - preoperational and operational support program conducted by Pacific Northwest Laboratory  

SciTech Connect

This report describes the radiological environmental sampling program that is being conducted at the US Department of Energy's (DOE) Hanford Site in support of resumed operation of the PUREX fuel processing plant. The report also summarizes preoperational radiological environmental data collected to date. The activities described herein are part of the ongoing Hanford Environmental Surveillance Program, operated by the Pacific Northwest Laboratory (PNL) for the DOE.

Sula, M.J.; Price, K.R.

1983-10-01

176

Laboratory experiments and modeling for industrial radiotracer applications.  

PubMed

This paper presents three laboratory experiments, which have been carried out using the Molybdenum-99 (Mo(99)) radiotracer to measure the residence time distribution (RTD), the mixing time and the flow rate in a water flow rig. The results of the RTD measurement experiment are preprocessed using the MATLAB software for background correction, radioactive decay correction, starting point correction, filtering, and data extrapolation. After preprocessing, six mathematical models are investigated on this data using the International Atomic Energy Agency (IAEA) RTD software. The parameters of each model are optimized to calculate the value of the RTD, and to determine the model, which gives the best match with the practical data. The selected model with the best match is used to calculate the RTD in this experiment. The mixing time experiment is carried out for different rotation speeds and repeated three times in each case. The results show that the mixing time is inversely proportional to the rotation speed. The flow rate experiment is carried out to measure the flow rate in the flow rig. The experimental results show a high reliability of the radiotracer used in the RTD, mixing time and flow rate measurements. PMID:20171110

Kasban, H; Zahran, O; Arafa, H; El-Kordy, M; Elaraby, S M S; Abd El-Samie, F E

2010-06-01

177

Laboratory and in-flight experiments to evaluate 3-D audio display technology  

NASA Technical Reports Server (NTRS)

Laboratory and in-flight experiments were conducted to evaluate 3-D audio display technology for cockpit applications. A 3-D audio display generator was developed which digitally encodes naturally occurring direction information onto any audio signal and presents the binaural sound over headphones. The acoustic image is stabilized for head movement by use of an electromagnetic head-tracking device. In the laboratory, a 3-D audio display generator was used to spatially separate competing speech messages to improve the intelligibility of each message. Up to a 25 percent improvement in intelligibility was measured for spatially separated speech at high ambient noise levels (115 dB SPL). During the in-flight experiments, pilots reported that spatial separation of speech communications provided a noticeable improvement in intelligibility. The use of 3-D audio for target acquisition was also investigated. In the laboratory, 3-D audio enabled the acquisition of visual targets in about two seconds average response time at 17 degrees accuracy. During the in-flight experiments, pilots correctly identified ground targets 50, 75, and 100 percent of the time at separation angles of 12, 20, and 35 degrees, respectively. In general, pilot performance in the field with the 3-D audio display generator was as expected, based on data from laboratory experiments.

Ericson, Mark; Mckinley, Richard; Kibbe, Marion; Francis, Daniel

1994-01-01

178

LABORATORY EXPERIMENTS, NUMERICAL SIMULATIONS, AND ASTRONOMICAL OBSERVATIONS OF DEFLECTED SUPERSONIC JETS: APPLICATION TO HH 110  

SciTech Connect

Collimated supersonic flows in laboratory experiments behave in a similar manner to astrophysical jets provided that radiation, viscosity, and thermal conductivity are unimportant in the laboratory jets and that the experimental and astrophysical jets share similar dimensionless parameters such as the Mach number and the ratio of the density between the jet and the ambient medium. When these conditions apply, laboratory jets provide a means to study their astrophysical counterparts for a variety of initial conditions, arbitrary viewing angles, and different times, attributes especially helpful for interpreting astronomical images where the viewing angle and initial conditions are fixed and the time domain is limited. Experiments are also a powerful way to test numerical fluid codes in a parameter range in which the codes must perform well. In this paper, we combine images from a series of laboratory experiments of deflected supersonic jets with numerical simulations and new spectral observations of an astrophysical example, the young stellar jet HH 110. The experiments provide key insights into how deflected jets evolve in three dimensions, particularly within working surfaces where multiple subsonic shells and filaments form, and along the interface where shocked jet material penetrates into and destroys the obstacle along its path. The experiments also underscore the importance of the viewing angle in determining what an observer will see. The simulations match the experiments so well that we can use the simulated velocity maps to compare the dynamics in the experiment with those implied by the astronomical spectra. The experiments support a model where the observed shock structures in HH 110 form as a result of a pulsed driving source rather than from weak shocks that may arise in the supersonic shear layer between the Mach disk and bow shock of the jet's working surface.

Hartigan, P.; Carver, R. [Rice University, Department of Physics and Astronomy, 6100 South Main, Houston, TX 77521-1892 (United States); Foster, J. M.; Rosen, P. A.; Williams, R. J. R. [Atomic Weapons Establishment, Aldermaston, Reading Berkshire, RG7 4PR (United Kingdom); Wilde, B. H.; Coker, R. F. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hansen, J. F. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States); Blue, B. E. [General Atomics, 3550 General Atomics Court, San Diego, CA 92121-1122 (United States); Frank, A. [University of Rochester, Department of Physics and Astronomy, Rochester, NY 14627-0171 (United States)

2009-11-01

179

Resonant solar neutrino oscillation versus laboratory neutrino oscillation experiments  

SciTech Connect

The interplay between resonant solar neutrino oscillations and neutrino oscillations in laboratory experiments is investigated in a 3 generation model. Due to the assumed hierarchy of neutrino masses, together with our choice of a convenient parameterization of the 3 generation mixing matrix, we can derive a simple analytic formula which reduces the solar neutrino problem to an effective 2 generation problem. The reduction makes it apparent that the allowed range of mixing and mass parameters crucially depend on whether the survival probability of solar neutrinos S satisfies S greater than or equal to 1/3 or not. The formulae for probabilities of laboratory neutrino oscillations are also greatly simplified. We argue that a combination of the observed solar neutrino depletion and data obtained from reactor experiments seems to rule out some range of neutrino masses. If a sizable nu/sub ..mu../ ..-->.. nu/sub e/ oscillation is observed at accelerators, as suggested at this Workshop, it severely restricts the range of 2 mixing angles.

Lim, Chong-Sa

1987-02-01

180

Subduction to Continental Delamination: Insights From Laboratory Experiments  

NASA Astrophysics Data System (ADS)

The evolution of the lithosphere through subduction-collision and delamination and its surface/crustal response (topography/deformation) is investigated in this work. We present a series of lithosphere scale two dimensional (2-D) and three dimensional (3-D) laboratory experiments to better understand such processes. In these experiments, an idealized viscously deforming crust-mantle lithosphere-mantle system is configured with silicone putty (representing lithospheric mantle and upper crust) and glucose syrup (representing the upper mantle and lower crust). The initial focus was to investigate the physical development of delamination versus continental subduction without plate convergence. Experiments show that the delamination or continental subduction is strongly dependent on the density of the crust (both crust and mantle lithosphere subducts when crust has a higher density, instead of delamination), while in the investigated range, the viscosity of the weak layer does not have much influence on the process. In all the experiments, the topography is asymmetric with subsidence above the delaminating hinge due to the dynamic vertical pulling driven by the delaminating slab, and uplift above the delaminated region due to the buoyancy of asthenosphere. Our investigation on the oceanic subduction with a convergence rate of ~ 3cm/year plate velocity suggests that subduction -collision - delamination is well defined and at the end, the delaminating crust from the lithosphere is overthrusted on top of the overriding plate. Our results provide integrated insights on the Alpine-Himalayan type orogenies, in particular the neotectonic evolution of Eastern Anatolian plateau.

Gogus, O. H.; Corbi, F.; Faccenna, C.; Pysklywec, R. N.

2009-05-01

181

Kinetics of Papain: An Introductory Biochemistry Laboratory Experiment  

NASA Astrophysics Data System (ADS)

Enzyme kinetics experiments are popular in the undergraduate laboratory. These experiments have pedagogic value because they reinforce the concepts of Michaelis-Menten kinetics covered in the lecture portion of the course and give students the experience of calculating kinetic constants from data they themselves have generated. In this experiment, we investigate the kinetics of the thiol protease papain. The source of the papain is commercially available papaya latex. A specific substrate, Na-benzoyl-arginine-p-nitroanilide (BAPNA), is used, which takes advantage of the fact that papain interacts with a phenylalanine residue two amino acids away from the peptide bond cleaved. Upon hydrolysis by papain, a bright yellow product is released, p-nitroaniline. This allows the reaction to be monitored spectrophotometrically by measuring the rate of formation of the p-nitroaniline product as a function of the increase in absorbance of the solution at the lmax of p-nitroaniline (400 nm) over time at various substrate concentrations. These data are used to plot a Lineweaver-Burk plot from which the vmax and KM are obtained. If time permits, students carry out additional investigations in which e of p-nitroaniline is measured, the enzyme solution protein concentration is measured, the enzyme purity is evaluated by SDS-PAGE, and a pH-rate profile is constructed from experimental data.

Cornely, Kathleen; Crespo, Eric; Earley, Michael; Kloter, Rachel; Levesque, Aime; Pickering, Mary

1999-05-01

182

Clinical and laboratory experience of chorionic villous sampling in Nigeria.  

PubMed

Background: Chorionic villous sampling is a first trimester invasive diagnosis procedure that was introduced in Nigeria < 2 decades ago. Objective: The objective of the following study is to review experience with chorionic villous sampling in relation to clinical and laboratory procedures, including general characteristics of women, indications and outcome, complications, laboratory analysis and learning curve. Materials and Methods: Descriptive study of chorionic villous samplings between 2005 and 2012. Clinical and laboratory data were extracted from records. The women had trans-abdominal or trans-cervical procedure after counseling. Deoxyribonucleic acid extraction was by boiling method and molecular diagnosis by restriction fragment length polymorphism or quantitative fluorescence polymerase chain reaction. Analyzed data were presented using simple frequency tables. Results: A total of 426 women were analyzed. The major indications were Sickle cell anemia (97.2%), gender determination (1.9%) and aneuploidy (0.7%) respectively. Most procedures (71.2%) were done between 11 +0 and 13 +6 weeks by trans-abdominal approach (88.7%). Overall success at the first sampling was 98.8%. Error in laboratory diagnosis recorded in 3 (0.7%) pregnancies, while 5 (1.2%) were reanalyzed due to maternal decidua/inadequate fetal sample (0.7%) or failure of amplification (0.5%) respectively. Primary sex ratio was 5 (XY): 3 (XX). Down syndrome was the most common aneuploidy diagnosed with a detection rate of 66.7%. Learning curve was evident from reducing the incidence of abortion, number of aspirations and increasing success at the first attempt and villi yield. Conclusion: The present study shows acceptance and utilization of chorionic villus sampling and also demonstrates its safety and reliability. PMID:24909479

Oloyede, O A; Olaide, A; Onyinye, N

2014-01-01

183

Thermal conductivity of polycrystalline CVD diamond: Experiment and theory  

SciTech Connect

The temperature dependences of thermal conductivity {kappa} of polycrystalline CVD diamond are measured in the temperature range from 5 to 410 K. The diamond sample is annealed at temperatures sequentially increasing from 1550 to 1690{sup o}C to modify the properties of the intercrystallite contacts in it. As a result of annealing, the thermal conductivity decreases strongly at temperatures below 45 K, and its temperature dependence changes from approximately quadratic to cubic. At T > 45 K, the thermal conductivity remains almost unchanged upon annealing at temperatures up to 1650{sup o}C and decreases substantially at higher annealing temperatures. The experimental data are analyzed in terms of the Callaway theory of thermal conductivity [9], which takes into account the specific role of normal phonon-phonon scattering processes. The thermal conductivity is calculated with allowance for three-phonon scattering processes, the diffuse scattering by sample boundaries, the scattering by point and extended defects, the specular scattering by crystallite boundaries, and the scattering by intercrystallite contacts. A model that reproduces the main specific features of the thermal conductivity of CVD diamond is proposed. The phonon scattering by intercrystallite contacts plays a key role in this model.

Inyushkin, A. V., E-mail: inyushkin@imp.kiae.ru; Taldenkov, A. N. [Russian Research Center Kurchatov Institute (Russian Federation); Ral'chenko, V. G.; Konov, V. I. [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Khomich, A. V. [Russian Academy of Sciences, Institute of Radio Engineering and Electronics (Fryazino branch) (Russian Federation); Khmel'nitskii, R. A. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)

2008-09-15

184

The Software Engineering Laboratory: An operational software experience factory  

NASA Technical Reports Server (NTRS)

For 15 years, the Software Engineering Laboratory (SEL) has been carrying out studies and experiments for the purpose of understanding, assessing, and improving software and software processes within a production software development environment at NASA/GSFC. The SEL comprises three major organizations: (1) NASA/GSFC, Flight Dynamics Division; (2) University of Maryland, Department of Computer Science; and (3) Computer Sciences Corporation, Flight Dynamics Technology Group. These organizations have jointly carried out several hundred software studies, producing hundreds of reports, papers, and documents, all of which describe some aspect of the software engineering technology that was analyzed in the flight dynamics environment at NASA. The studies range from small, controlled experiments (such as analyzing the effectiveness of code reading versus that of functional testing) to large, multiple project studies (such as assessing the impacts of Ada on a production environment). The organization's driving goal is to improve the software process continually, so that sustained improvement may be observed in the resulting products. This paper discusses the SEL as a functioning example of an operational software experience factory and summarizes the characteristics of and major lessons learned from 15 years of SEL operations.

Basili, Victor R.; Caldiera, Gianluigi; Mcgarry, Frank; Pajerski, Rose; Page, Gerald; Waligora, Sharon

1992-01-01

185

Laboratory Astrophysics Experiments with Magnetically Driven Plasma Jets  

NASA Astrophysics Data System (ADS)

We present experimental results on the formation of supersonic, radiatively cooled jets driven by the toroidal magnetic field generated by the 1.5 MA, 250 ns current from the MAGPIE generator. The morphology of the jet produced in the experiments is relevant to astrophysical jet scenarios in which the jet on the axis of a magnetic cavity expanding into an ambient medium is collimated by a toroidal magnetic field. The jets in our experiments have similar Mach number, plasma beta and cooling parameter to those in protostellar jets and additionally the Reynolds, magnetic Reynolds and Peclet numbers are much larger than unity, allowing the experiments to be scaled to astrophysical flows. The experimental configuration generates episodic magnetic cavities, suggesting that periodic formation of jets in astrophysical situations could be responsible for some of the variability observed in astrophysical jets. The dynamics of the formation of laboratory jets are presented, together with new results including preliminary measurements of magnetic, kinetic and Poynting energy of the outflows. In addition first estimates of jet temperature and trapped toroidal magnetic field are presented and discussed.

Suzuki-Vidal, F.; Lebedev, S. V.; Ciardi, A.; Bland, S. N.; Hall, G. N.; Swadling, G.; Harvey-Thompson, A. J.; Burdiak, G.; de Grouchy, P.; Chittenden, J. P.; Bocchi, M.; Bott, S. C.; Frank, A.

2014-05-01

186

Scaled Laboratory Collisionless Shock Experiments in the Large Plasma Device  

NASA Astrophysics Data System (ADS)

Collisionless shocks in space plasmas have been investigated since the fifties and are typically studied via in-situ satellite observations, which are limited due to the large structure of collisionless shocks in space environments relative to the satellite observation platform. Scaled, repeatable experiments in the Large Plasma Device (LAPD) at UCLA provide a test bed for studying collisionless shocks in the laboratory, where questions of ion and electron heating and acceleration can be addressed and examined in detail. The experiments are performed by ablating a graphite or plastic target using the Raptor kilojoule-class laser facility at UCLA. The laser provides an on-target energy in the range of 100-500 J that drives a super-Alfvénic (MA > 1) debris plasma across a background magnetic field (200-800 G) into the ambient, magnetized LAPD plasma. Typical plasma parameters in the LAPD consist of a H+ or He+ ambient plasma with a core column (diameter > 20 cm ) density ni ~ 1013 cm-3 and electron temperature Te ~ 10 eV embedded in a larger plasma discharge (diameter ~ 80 cm) of density ni ~ 1012 cm-3 and Te ~ 5 eV. The ambient ion temperature is Ti ~ 1 eV. Experimental results from the latest collisionless shock campaign will be presented and compared with two dimensional hybrid simulations of the experiment. Fielded diagnostics include Thomson scattering, ion spectroscopy, magnetic flux probes, Langmuir probes, and microwave reflectometry.

Clark, S. E.; Schaeffer, D.; Everson, E.; Bondarenko, A.; Winske, D.; Constantin, C.; Niemann, C.

2013-12-01

187

Simulating the volatilization of solvents in unsaturated soils during laboratory and field infiltration experiments  

NASA Astrophysics Data System (ADS)

This paper describes laboratory and field experiments which were conducted to study the dynamics of trichloroethylene (TCE) as it volatilized from contaminated groundwater and diffused in the presence of infiltrating water through the unsaturated soil zone to the land surface. The field experiments were conducted at the Picatinny Arsenal, which is part of the United States Geological Survey Toxic Substances Hydrology Program. In both laboratory and field settings the gas and water phase concentrations of TCE were not in equilibrium during infiltration. Gas-water mass transfer rate constants were calibrated to the experimental data using a model in which the water phase was treated as two phases: a mobile water phase and an immobile water phase. The mass transfer limitations of a volatile organic compound between the gas and liquid phases were described explicitly in the model. In the laboratory experiment the porous medium was nonsorbing, and water infiltration rates ranged from 0.076 to 0.28 cm h-1. In the field experiment the water infiltration rate was 0.34 cm h-1, and sorption onto the soil matrix was significant. The laboratory-calibrated gas-water mass transfer rate constant is 3.3×10-4 h-1 for an infiltration rate of 0.076 cm h-1 and 1.4×10-3 h-1 for an infiltration rate of 0.28 cm h-1. The overall mass transfer rate coefficients, incorporating the contribution of mass transfer between mobile and immobile water phases and the variation of interfacial area with moisture content, range from 3×10-4 h-1 to 1×10-2 h-1. A power law model relates the gas-water mass transfer rate constant to the infiltration rate and the fraction of the water phase which is mobile. It was found that the results from the laboratory experiments could not be extrapolated to the field. In order to simulate the field experiment the very slow desorption of TCE from the soil matrix was incorporated into the mathematical model. When desorption from the soil matrix was added to the model, the calibrated gas-water mass transfer rate constant is 2 orders of magnitude lower than that predicted using the power law model developed for the nonsorbing laboratory soil.

Cho, H. Jean; Jaffé, Peter R.; Smith, James A.

1993-10-01

188

Report on Experiment Conducted on Lake Tanganyika, April 1969.  

National Technical Information Service (NTIS)

A series of hydrological and biological tests were conducted on Lake Tanganyika to examine the effects of 1.8 pound TNT explosive sound signals on the commercial fishery found there. The evaluation of the explosive effects was a preliminary requirement fo...

E. N. Jones A. L. Brooks

1969-01-01

189

Laboratory experiment of the rock anelastic strain recovery compliances  

NASA Astrophysics Data System (ADS)

Anelastic strain recovery (ASR) compliances are the important parameters for the ASR in situ stress measurement method to accurately evaluate the magnitude of the stress. The laboratory experiment of the creep and ASR processes for three types of rocks (sandstone, marble and granite) were performed. The tests were carried out at 50% of the uniaxial compressive strength (UCS). And the ASR compliances of the shear mode Jas(t), the volumetric mode Jav(t) and the ratio of Jas(t) and Jav(t) were obtained, respectively. The experimental result show that both the magnitude and increase rate of the ASR compliance greatly depend on the rock type, and the ratios of Jas(t) and Jav(t) trend to different constant values after enough elapsed time for each type of rock specimen.

Gao, Lu; Wang, Lianjie

2012-09-01

190

Apex expansion of magnetized plasma loops in a laboratory experiment  

NASA Astrophysics Data System (ADS)

Arch-shaped magnetic flux tubes are generated in a pulsed laboratory experiment. As the axial plasma current rises, the apex of the arches is found to expand with constant velocity. This conflicts with the common assumption that plasma expansion in this type of configuration is caused by the hoop force. We propose that drift movement in the electric field arising from the experimentally applied voltage pulse and the plasma current's magnetic field can lead to a significant alteration of the expansion characteristics. To this end, probe measurements of magnetic and electric fields in the plasma are presented and the corresponding drift velocity is evaluated. The proposed mechanism is discussed in the context of recent results of numerical (Tacke et al 2013 Phys. Plasmas 20 072104) and experimental (Stenson et al 2012 Phys. Rev. Lett. 109 075001) investigations of flux rope expansion in similar configurations.

Tenfelde, J.; Mackel, F.; Ridder, S.; Tacke, T.; Kempkes, P.; Soltwisch, H.

2014-05-01

191

Slew maneuvers of Spacecraft Control Laboratory Experiment (SCOLE)  

NASA Technical Reports Server (NTRS)

This is the final report on the dynamics and control of slew maneuvers of the Spacecraft Control Laboratory Experiment (SCOLE) test facility. The report documents the basic dynamical equation derivations for an arbitrary large angle slew maneuver as well as the basic decentralized slew maneuver control algorithm. The set of dynamical equations incorporate rigid body slew maneuver and three dimensional vibrations of the complete assembly comprising the rigid shuttle, the flexible beam, and the reflector with an offset mass. The analysis also includes kinematic nonlinearities of the entire assembly during the maneuver and the dynamics of the interactions between the rigid shuttle and the flexible appendage. The equations are simplified and evaluated numerically to include the first ten flexible modes to yield a model for designing control systems to perform slew maneuvers. The control problem incorporates the nonlinear dynamical equations and is expressed in terms of a two point boundary value problem.

Kakad, Yogendra P.

1992-01-01

192

The Nature of Laboratory Learning Experiences in Secondary Science Online  

NASA Astrophysics Data System (ADS)

Teaching science to secondary students in an online environment is a growing international trend. Despite this trend, reports of empirical studies of this phenomenon are noticeably missing. With a survey concerning the nature of laboratory activities, this study describes the perspective of 35-secondary teachers from 15-different U.S. states who are teaching science online. The type and frequency of reported laboratory activities are consistent with the tradition of face-to-face instruction, using hands-on and simulated experiments. While provided examples were student-centered and required the collection of data, they failed to illustrate key components of the nature of science. The features of student-teacher interactions, student engagement, and nonverbal communications were found to be lacking and likely constitute barriers to the enactment of inquiry. These results serve as a call for research and development focused on using existing communication tools to better align with the activity of science such that the nature of science is more clearly addressed, the work of students becomes more collaborative and authentic, and the formative elements of a scientific inquiry are more accessible to all participants.

Crippen, Kent J.; Archambault, Leanna M.; Kern, Cindy L.

2013-06-01

193

Rainfall estimation using moving cars as rain gauges - laboratory experiments  

NASA Astrophysics Data System (ADS)

The spatial assessment of short time-step precipitation is a challenging task. Low density of observation networks, as well as the bias in radar rainfall estimation motivated the new idea of exploiting cars as moving rain gauges with windshield wipers or optical sensors as measurement devices. In a preliminary study, this idea has been tested with computer experiments (Haberlandt and Sester, 2010). The results have shown that a high number of possibly inaccurate measurement devices (moving cars) provide more reliable areal rainfall estimations than a lower number of precise measurement devices (stationary gauges). Instead of assuming a relationship between wiper frequency (W) and rainfall intensity (R) with an arbitrary error, the main objective of this study is to derive valid W-R relationships between sensor readings and rainfall intensity by laboratory experiments. Sensor readings involve the wiper speed, as well as optical sensors which can be placed on cars and are usually made for automating wiper activities. A rain simulator with the capability of producing a wide range of rainfall intensities is designed and constructed. The wiper speed and two optical sensors are used in the laboratory to measure rainfall intensities, and compare it with tipping bucket readings as reference. Furthermore, the effect of the car speed on the estimation of rainfall using a car speed simulator device is investigated. The results show that the sensor readings, which are observed from manual wiper speed adjustment according to the front visibility, can be considered as a strong indicator for rainfall intensity, while the automatic wiper adjustment show weaker performance. Also the sensor readings from optical sensors showed promising results toward measuring rainfall rate. It is observed that the car speed has a significant effect on the rainfall measurement. This effect is highly dependent on the rain type as well as the windshield angle.

Rabiei, E.; Haberlandt, U.; Sester, M.; Fitzner, D.

2013-11-01

194

Rainfall estimation using moving cars as rain gauges - laboratory experiments  

NASA Astrophysics Data System (ADS)

The spatial assessment of short time step precipitation is a challenging task. Low density of observation networks, as well as the bias in radar rainfall estimation motivated the new idea of exploiting cars as moving rain gauges with windshield wipers or optical sensors as measurement devices. In a preliminary study, this idea has been tested with computer experiments (Haberlandt and Sester, 2010). The results have shown that a high number of possibly inaccurate measurement devices (moving cars) provide more reliable areal rainfall estimations than a lower number of precise measurement devices (stationary gauges). Instead of assuming a relationship between wiper frequency (W) and rainfall intensity (R) with an arbitrary error, the main objective of this study is to derive valid W-R relationships between sensor readings and rainfall intensity by laboratory experiments. Sensor readings involve the wiper speed, as well as optical sensors which can be placed on cars and are usually made for automating wiper activities. A rain simulator with the capability of producing a wide range of rainfall intensities is designed and constructed. The wiper speed and two optical sensors are used in the laboratory to measure rainfall intensities, and compare it with tipping bucket readings as reference. Furthermore, the effect of the car speed on the estimation of rainfall using a car speed simulator device is investigated. The results show that the sensor readings, which are observed from wiper speed adjustment according to the front visibility, can be considered as a strong indicator for rainfall intensity. Also the optical sensors showed promising results toward measuring rainfall rate. It is observed that the car speed has a significant effect on the rainfall measurement. This effect is highly dependent on the rain type as well as the windshield angle.

Rabiei, E.; Haberlandt, U.; Sester, M.; Fitzner, D.

2013-04-01

195

LABORATORY EXPERIMENTS TO SIMULATE CO2 OCEAN DISPOSAL  

SciTech Connect

This Final Technical Report summarizes the technical accomplishments of an investigation entitled ''Laboratory Experiments to Simulate CO{sub 2} Ocean Disposal'', funded by the U.S. Department of Energy's University Coal Research Program. This investigation responds to the possibility that restrictions on greenhouse gas emissions may be imposed in the future to comply with the Framework Convention on Climate Change. The primary objective of the investigation was to obtain experimental data that can be applied to assess the technical feasibility and environmental impacts of oceanic containment strategies to limit release of carbon dioxide (CO{sub 2}) from coal and other fossil fuel combustion systems into the atmosphere. A number of critical technical uncertainties of ocean disposal of CO{sub 2} were addressed by performing laboratory experiments on liquid CO{sub 2} jet break-up into a dispersed droplet phase, and hydrate formation, under deep ocean conditions. Major accomplishments of this study included: (1) five jet instability regimes were identified that occur in sequence as liquid CO{sub 2} jet disintegration progresses from laminar instability to turbulent atomization; (2) linear regression to the data yielded relationships for the boundaries between the five instability regimes in dimensionless Ohnesorge Number, Oh, and jet Reynolds Number, Re, space; (3) droplet size spectra was measured over the full range of instabilities; (4) characteristic droplet diameters decrease steadily with increasing jet velocity (and increasing Weber Number), attaining an asymptotic value in instability regime 5 (full atomization); and (5) pre-breakup hydrate formation appears to affect the size distribution of the droplet phase primary by changing the effective geometry of the jet.

Stephen M. Masutani

1999-12-31

196

Experimenting in a constructivist high school physics laboratory  

NASA Astrophysics Data System (ADS)

Although laboratory activities have long been recognized for their potential to facilitate the learning of science concepts and skills, this potential has yet to be realized. To remediate this problem, researchers have called for constructivist learning environments in which students can pursue open inquiry and frame their own research problems. The present study was designed to describe and understand students' experimenting and problem solving in such an environment. An interpretive research methodology was adopted for the construction of meaning from the data. The data sources included videotapes, their transcripts, student laboratory reports and reflections, interviews with the students, and the teacher's course outline and reflective notes. Forty-six students from three sections of an introductory physics course taught at a private school for boys participated in the study. This article shows the students' remarkable ability and willingness to generate research questions and to design and develop apparatus for data collection. In their effort to frame research questions, students often used narrative explanations to explore and think about the phenomena to be studied. In some cases, blind alleys, students framed research questions and planned experiments that did not lead to the expected results. We observed a remarkable flexibility to deal with problems that arose during the implementation of their plans in the context of the inquiry. These problems, as well as their solutions and the necessary decision-making processes, were characterized by their situated nature. Finally, students pursued meaningful learning during the interpretation of data and graphs to arrive at reasonable answers of their research questions. We concluded that students should be provided with problem-rich learning environments in which they learn to investigate phenomena of their own interest and in which they can develop complex problem-solving skills.

Roth, Wolff-Michael

197

Astronaut Mike Fincke Conducts Fluid Merging Viscosity Measurement (FMVM) Experiment  

NASA Technical Reports Server (NTRS)

Astronaut Mike Fincke places droplets of honey onto the strings for the Fluid Merging Viscosity Measurement (FMVM) investigation onboard the International Space Station (ISS). The FMVM experiment measures the time it takes for two individual highly viscous fluid droplets to coalesce or merge into one droplet. Different fluids and droplet size combinations were tested in the series of experiments. By using the microgravity environment, researchers can measure the viscosity or 'thickness' of fluids without the influence of containers and gravity using this new technique. Understanding viscosity could help scientists understand industrially important materials such as paints, emulsions, polymer melts and even foams used to produce pharmaceutical, food, and cosmetic products.

2004-01-01

198

Status of the Nuclear-Induced Conductivity Experiment (NICE) Project  

NASA Technical Reports Server (NTRS)

Nuclear-based magnetohydrodynamic (MHD) energy conversion has been pursued in various forms since the 1950's. The majority of this work was motivated by the compatibility of MHD generators with the high temperature achievable with a nuclear reactor and the associated potential for very high cycle efficiency. As a result of this perspective, methods for enhancing the electrical conductivity of the MHD flow have primarily focused on traditional thermal ionization processes, especially those utilizing alkali metal seeds. However, electrical conductivity enhancement via thermal interactions imposes significant limitations on the flow expansion through the generator, and hence on the ultimate power density. Furthermore, the introduction of an alkali metal seed into the flow significantly complicates the engineering design and increases the potential for system failures due to plating of the evaporated metal on cold surfaces.

Bitteker, Leo; Bragg-Sitton, Shannon M.; Litchford, Ron J.; Rodgers, Stephen L. (Technical Monitor)

2001-01-01

199

Definition of experiments and instruments for a communication/navigation research laboratory. Volume 3: Laboratory descriptions  

NASA Technical Reports Server (NTRS)

The following study objectives are covered: (1) identification of major laboratory equipment; (2) systems and operations analysis in support of the laboratory design; and (3) conceptual design of the comm/nav research laboratory.

1972-01-01

200

Episodic ``Magnetic Tower'' Plasma Jets in a Laboratory Experiment  

NASA Astrophysics Data System (ADS)

We will present experimental results on formation of supersonic magnetically driven plasma jets with dimensionless parameters similar to those in proto-stellar jets. The jets are driven by the pressure of the toroidal magnetic field and the plasma beta in these jets is of the order of unity [1,2]. The experimental configuration allows generation of several episodes of the magnetic tower jet eruptions. The subsequent magnetic bubbles have higher propagation velocities and are catching up the previously ejected, producing shocks. These experiments suggest that periodic formation of magnetic tower jets in the astrophysical situations could be responsible for some of the variability of the astrophysical jets. The experiments are scalable to astrophysical flows in that critical dimensionless numbers such as the plasma collisionality, the plasma beta and the magnetic Reynolds number are all in the astrophysically appropriate ranges. The experimental results will be compared with computer simulations performed with laboratory plasma codes and with astrophysical codes. [1] S.V. Lebedev et al., Mon. Not. R. Astron. Soc., 361 97 (2005) [2] A. Ciardi et al., Physics of Plasmas, 14, 056501 (2007). In collaboration with: A. CIARDI, F.A. SUZUKI-VIDAL, S.N. BLAND, S.C. BOTT, J.P. CHITTENDEN, G. HALL, A. HARVEY-THOMSON, A. MAROCCHINO, A. FRANK, E. G. BLACKMAN, T. RAY, C. STEHLE

Lebedev, Sergey

2008-04-01

201

Laboratory Experiments on Convective Entrainment Using a Saline Water Tank  

NASA Astrophysics Data System (ADS)

Entrainment fluxes in a shear-free convective boundary layer have been measured with a saline water tank set-up. The experiments were targeted towards measuring the entrainment behaviour for medium to high Richardson numbers and use a two-layer design, i.e. two stacked non-stratified (neutral) layers with different densities. With laser induced fluorescence (LIF), the entrainment flux of a fluorescent dye is measured for bulk Richardson numbers in the range 30-260. It is proposed that a carefully chosen combination of top-down and bottom-up processes improves the accuracy of LIF-based entrainment observations. The observed entrainment fluxes are about an order of magnitude lower than reported for thermal water tanks: the derived buoyancy entrainment ratio, , is found to be , which is to be compared with for a thermal convection tank (Deardorff et al., J Fluid Mech 100:41-64, 1980). An extensive discussion is devoted to the influence of the Reynolds and Prandtl numbers in laboratory experiments on entrainment.

Jonker, Harmen J. J.; Jiménez, Maria A.

2014-06-01

202

Conductivity  

NSDL National Science Digital Library

Students make a simple conductivity tester using a battery and light bulb. They learn the difference between conductors and insulators of electrical energy as they test a variety of materials for their ability to conduct electricity.

Integrated Teaching And Learning Program

203

Impact of General Physics Laboratory II Course on Recognizing Electricity Experiments' Tools  

NASA Astrophysics Data System (ADS)

In this study, the abilities related to the tools and their functions that are used in electrical experiments in the general physics laboratory II courses by the 1st grade students attending the education of science teaching in Balikesir University, in 2005-2006 education year has been researched. The measuring tool used in our research consists of 3 parts and it has been applied to 82 students as pre-test and post- test. Also semi-constructed interviews have been conducted with 8 students among them. The data obtained at the end of the research have been analyzed and discussed with the aim.

Ege, Y.; Çirkino?lu, A. G.; Aytaç, N.; Özcan, H.

2007-04-01

204

The Multiwell Experiment; A field laboratory in tight gas sandstone reservoirs  

SciTech Connect

This paper reports on the U.S. DOE's Multiwell Experiment (MWX), a field laboratory aimed at improved characterization and gas production from low-permeability reservoirs typified by the Mesaverde Group in western Colorado. A broad spectrum of activities was conducted over 8 years at a site containing three closely spaced (< 225 ft (< 68 m)), deep (7,500 to 8,350 ft (2300 to 2550 m)) wells. The results yield insights and contributions into the technology of gas production from this resource.

Northrop, D.A.; Frohne, K.H. (Sandia National Labs., Albuquerque, NM (USA))

1990-06-01

205

Numerical and laboratory experiment of volumetrically heated fluid: implications of boundary conditions on planetary evolution.  

NASA Astrophysics Data System (ADS)

In the last decade numerical simulations of mantle convection have included an increasing number of physical processes (e.g., phase transitions, compositional heterogeneities, depth dependent properties), to gain a better understanding of the Earth's thermal evolution. This increasing complexity has led to a more precise description of the convective behavior of the Earth's mantle, but may have render its deciphering somewhat more difficult and sometimes ambiguous. Coupled experimental and numerical studies are then useful to interpret the results of the modeling. Here we present numerical simulations of a simple system, which is only cooled from above and internally heated, coupled with innovative laboratory experiments. Three-dimensional simulations are conducted with the code Stag3D [Tackley 1993], and the laboratory experiments used a newtonian fluid whose viscosity and thermal expansion are both temperature dependent. The experimental approach, presented in detail in a companion abstract by Limare at al. (EGU2014-6207), is very challenging and it was first important to validate numerically the experimentally measured temperature and velocity fields. We then used the combined approach to quantify the effect of boundary conditions (i.e., rigid, as in the laboratory experiments, or free slip) on the internal thermal structure of the convective fluid. In particular, we calculate the horizontally and time-averaged temperature across the top thermal boundary layer for a large range of Rayleigh number (105

Vilella, Kenny; Limare, Angela; Kaminski, Edouard; Farnetani, Cinzia G.; Jaupart, Claude; Surducan, Emanoil; Di Giuseppe, Erika; Surducan, Vasile; Neamtu, Camelia; Fourel, Loic

2014-05-01

206

Aqueous geochemistry of low molecular weight hydrocarbons at elevated temperatures and pressures: constraints from mineral buffered laboratory experiments  

Microsoft Academic Search

Organic matter, water, and minerals coexist at elevated temperatures and pressures in sedimentary basins and participate in a wide range of geochemical processes that includes the generation of oil and natural gas. A series of laboratory experiments were conducted at 300 to 350°C and 350 bars to examine chemical interactions involving low molecular weight aqueous hydrocarbons with water and Fe-bearing

Jeffrey S. Seewald

2001-01-01

207

Conducting Closed Habitation Experiments: Experience from the Lunar Mars Life Support Test Project  

NASA Technical Reports Server (NTRS)

The Lunar-Mars Life Support Test Project (LMLSTP) was conducted from 1995 through 1997 at the National Aeronautics and Space Administration s (NASA) Johnson Space Center (JSC) to demonstrate increasingly longer duration operation of integrated, closed-loop life support systems that employed biological and physicochemical techniques for water recycling, waste processing, air revitalization, thermal control, and food production. An analog environment for long-duration human space travel, the conditions of isolation and confinement also enabled studies of human factors, medical sciences (both physiology and psychology) and crew training. Four tests were conducted, Phases I, II, IIa and III, with durations of 15, 30, 60 and 91 days, respectively. The first phase focused on biological air regeneration, using wheat to generate enough oxygen for one experimental subject. The systems demonstrated in the later phases were increasingly complex and interdependent, and provided life support for four crew members. The tests were conducted using two human-rated, atmospherically-closed test chambers, the Variable Pressure Growth Chamber (VPGC) and the Integrated Life Support Systems Test Facility (ILSSTF). Systems included test articles (the life support hardware under evaluation), human accommodations (living quarters, kitchen, exercise equipment, etc.) and facility systems (emergency matrix system, power, cooling, etc.). The test team was managed by a lead engineer and a test director, and included test article engineers responsible for specific systems, subsystems or test articles, test conductors, facility engineers, chamber operators and engineering technicians, medical and safety officers, and science experimenters. A crew selection committee, comprised of psychologists, engineers and managers involved in the test, evaluated male and female volunteers who applied to be test subjects. Selection was based on the skills mix anticipated for each particular test, and utilized information from psychological and medical testing, data on the knowledge, experience and skills of the applicants, and team building exercises. The design, development, buildup and operation of test hardware and documentation followed the established NASA processes and requirements for test buildup and operation.

Barta, Daniel J.; Edeen, Marybeth A.; Henninger, Donald L.

2006-01-01

208

Conducting Closed Habitation Experiments: Experience from the Lunar Mars Life Support Test Project  

NASA Technical Reports Server (NTRS)

The Lunar-Mars Life Support Test Project (LMLSTP) was conducted from 1995 through 1997 at the National Aeronautics and Space Administration s (NASA) Johnson Space Center (JSC) to demonstrate increasingly longer duration operation of integrated, closed-loop life support systems that employed biological and physicochemical techniques for water recycling, waste processing, air revitalization, thermal control, and food production. An analog environment for long-duration human space travel, the conditions of isolation and confinement also enabled studies of human factors, medical sciences (both physiology and psychology) and crew training. Four tests were conducted, Phases I, II, IIa and III, with durations of 15, 30,60 and 91 days, respectively. The first phase focused on biological air regeneration, using wheat to generate enough oxygen for one experimental subject. The systems demonstrated in the later phases were increasingly complex and interdependent, and provided life support for four crew members. The tests were conducted using two human-rated, atmospherically-closed test chambers, the Variable Pressure Growth Chamber (VPGC) and the Integrated Life Support Systems Test Facility (ILSSTF). Systems included test articles (the life support hardware under evaluation), human accommodations (living quarters, kitchen, exercise equipment, etc.) and facility systems (emergency matrix system, power, cooling, etc.). The test team was managed by a lead engineer and a test director, and included test article engineers responsible for specific systems, subsystems or test articles, test conductors, facility engineers, chamber operators and engineering technicians, medical and safety officers, and science experimenters. A crew selection committee, comprised of psychologists, engineers and managers involved in the test, evaluated male and female volunteers who applied to be test subjects. Selection was based on the skills mix anticipated for each particular test, and utilized information from psychological and medical testing, data on the knowledge, experience and skills of the applicants, and team building exercises. The design, development, buildup and operation of test hardware and documentation followed the established NASA processes and requirements for test buildup and operation.

Barta, Daniel J.; Edeen, Marybeth A.; Henninger, Donald L.

2004-01-01

209

Erosion processes in granular flows: insights from laboratory experiments  

NASA Astrophysics Data System (ADS)

Experimental granular column collapse were conducted over an inclined channel covered by an erodible bed of granular material in order to reproduce at laboratory scale erosion processes of natural flows propagating over deposits formed by earlier events. The studied control parameters were the slope angle, the aspect ratio (i.e. height over length), the volume and the shape of the granular column released, and the thickness and compaction of the erodible bed. The results show that erosion processes affect the flow runout distance over a critical slope angle ?c that depends on the column volume, aspect ratio, and shape. For slope higher than ?c, the granular avalanche excavates the erodible layer immediately at the flow front, behind which waves traveling downstream are observed and help entraining grains from the erodible bed. Erosion efficiency (i.e. maximal depth and duration of excavation, waves dimensions) is shown to increase as the slope angle and the column's volume increase. It is also dependent on the aspect ratio and on the nature of the erodible bed: the maximal excavation depth and the duration of the excavation decrease as the degree of compaction of the erodible granular bed increases. Erosion processes notably increase granular flows runout distance at inclinations close to the repose angle of the grains, in particular for columns of small aspect ratio. We demonstrate, however, that the flow runout distance observed on an erodible bed cannot be reproduced on a rough bed by simply adding the entrained volume of erodible bed to the initial column volume.

Farin, Maxime; Mangeney, Anne; Roche, Olivier

2013-04-01

210

Evaporation of J13 water: laboratory experiments and geochemical modeling  

SciTech Connect

We report results from experiments on the evaporative chemical evolution of synthetic J13 water, representative of water from well J13, a common reference water in the Yucca Mountain Project. Data include anion and cation analysis and qualitative mineral identification for a series of open system experiments, with and without crushed tuff present, conducted at sub-boiling temperatures. Ca and Mg precipitated readily as carbonates and anions Cl, F, NO{sub 3} and SO{sub 4} remained in solution in nearly identical ratios. The pH stabilized at about 10. After {approx} 1000x concentration, the minerals formed were amorphous silica, aragonite and calcite. The presence of tuff appears to have very little effect on the relative distribution of the anions in solution, except for possibly F, which had a relatively lower concentration ratio. The Si was lower in the solutions with tuff present suggesting that the tuff enhances SiO{sub 2} precipitation. Even though the tools to model highly-concentrated salt solutions are limited, we compare our experimental results with the results of geochemical models, with (perhaps) surprising good results. In response to different assumed CO{sub 2} levels, pH varied, but anion concentrations were not greatly affected.

Dibley, M.J.; Knauss, K.G.; Rosenberg, N.D.

1999-08-11

211

Laboratory evaluation of time domain reflectometry for continuous monitoring of stream stage, channel profile and aqueous conductivity.  

SciTech Connect

Time domain reflectometry (TDR) operates by propagating a radar frequency electromagnetic pulse down a transmission line while monitoring the reflected signal. As the electromagnetic pulse propagates along the transmission line, it is subject to impedance by the dielectric properties of the media along the transmission line (e.g., air, water, and sediment), reflection at dielectric discontinuities (e.g., air-water or water-sediment interface), and attenuation by electrically conductive materials (e.g., salts and clays). Taken together, these characteristics provide a basis for integrated stream monitoring, specifically, concurrent measurement of stream stage, channel profile, and aqueous conductivity. Requisite for such application is a means of extracting the desired stream parameters from measured TDR traces. Analysis is complicated by the fact that interface location and aqueous conductivity vary concurrently and multiple interfaces may be present at any time. For this reason a physically based multisection model employing the S11 scatter function and Debeye parameters for dielectric dispersion and loss is used to analyze acquired TDR traces. Here we explore the capability of this multisection modeling approach for interpreting TDR data acquired from complex environments, such as encountered in stream monitoring. A series of laboratory tank experiments was performed in which the depth of water, depth of sediment, and conductivity were varied systematically. Comparisons between modeled and independently measured data indicate that TDR measurements can be made with an accuracy of {+-} 3.4 x 10{sup -3} m for sensing the location of an air-water or water-sediment interface and {+-} 7.4% of actual for the aqueous conductivity.

Tidwell, Vincent Carroll; Brainard, James Robert

2005-03-01

212

Calcium-activated conductance in skate electroreceptors: current clamp experiments  

PubMed Central

When current clamped, skate electroreceptor epithelium produces large action potentials in response to stimuli that depolarize the lumenal faces of the receptor cells. With increasing stimulus strength these action potentials become prolonged. When the peak voltage exceeds about 140 mV the repolarizing phase is blocked until the end of the stimulus. Perfusion experiments show that the rising phase of the action potential results from an increase in calcium permeability in the lumenal membranes. Perfusion of the lumen with cobalt or with a zero calcium solution containing EGTA blocks the action potential. Perfusion of the lumen with a solution containing 10 mM Ca and 20 mM EGTA initially slows the repolarizing process at all voltages and lowers the potential at which it is blocked. With prolonged perfusion, repolarization is blocked at all voltages. When excitability is abolished by perfusion with cobalt, or with a zero calcium solution containing EGTA, no delayed rectification occurs. We suggest that repolarization during the action potential depends on an influx of calcium into the cytoplasm, and that the rate of repolarization depends on the magnitude of the inward calcium current. Increasingly large stimuli reduce the rate of repolarization by reducing the driving force for calcium, and then block repolarization by causing the lumenal membrane potential to exceed ECa. Changes in extracellular calcium affect repolarization in a manner consistent with the resulting change in ECa.

1977-01-01

213

Calcium-activated conductance in skate electroreceptors: voltage clamp experiments  

PubMed Central

Voltage clamp experiments allow further characterization of the calcium- dependent repolarizing process in skate electroreceptor epithelium. Four current components are described: a prolonged capacity current, a leakage current, an early active current which flows inward across the lumenal membranes of the receptor cells, and a late current which flows outward. The leakage and capacity currents are linear and may be substracted from the total current, giving net active currents. The early active current is carried by calcium and does not undergo inactivation for at least several seconds. When large stimuli exceed the reversal potential for the early calcium current, the late current is suppressed. Reduction of the ionized calcium concentration in the lumen lowers the reversal potential for the early current and the suppression potential for the late current by the same amount. We conclude that the late current is initiated by a calcium influx into the cytoplasm. During pulses of moderate duration, activation of the late current does not begin until a fixed amount of calcium has entered the receptor cells. The required amount of calcium is reduced if a recent calcium influx has occurred. We suggest that the calcium- activated outward current is mediated by a distinct macromolecule that is insensitive to voltage. Such macromolecules are likely to have an important role in the regulation of electrical activity in excitable cells.

1977-01-01

214

Thermal conductivity of polyisocyanurate foam board insulation blown with CFC-11 substitutes: Laboratory and long-term field measurements.  

National Technical Information Service (NTIS)

This paper reports on a series of laboratory and controlled test site measurements of the thermal conductivity of polyisocyanurate foam laminated boardstock roof insulations produced with several different blowing agents; CFC-11, HCFC-123, HCFC-14lb, and ...

G. E. Courville J. E. Christian R. S. Graves

1992-01-01

215

An approach to Poiseuille's law in an undergraduate laboratory experiment  

NASA Astrophysics Data System (ADS)

The continuous growth of computer and sensor technology allows many researchers to develop simple modifications and/or refinements to standard educational experiments, making them more attractive and comprehensible to students and thus increasing their educational impact. In the framework of this approach, the present study proposes an alternative experimental setup, which allows the confirmation of Hagen-Poiseuille's law, governing the flow of real fluids through tubes, a law with numerous important applications in both technology and medicine. In the proposed educational procedure, experimental measurements of fluid outflow are performed with the use of a motion sensor and a suitable computer program, allowing the determination of both the hydrostatic pressure and the flow rate. The dependence of the flow rate on parameters such as viscosity of the fluid, length and radius of the tube and the pressure difference between the ends of the tube are also studied, providing a laboratory activity which is useful and attractive for first year students, especially those of technologically oriented departments.

Sianoudis, I. A.; Drakaki, E.

2008-05-01

216

Joint Langley Research Center/Jet Propulsion Laboratory CSI experiment  

NASA Technical Reports Server (NTRS)

This paper describes a joint Control Structure Interaction (CSI) experiment in which Jet Propulsion Laboratory (JPL) damping devices were incorporated into the Langley Research Center (LaRC) Phase 0 Testbed. The goals of the effort were twofold: (1) test the effectiveness of the JPL structural damping methods in a new structure and (2) assess the feasibility of combining JPL local control methods with the LaRC multiple input multiple output global control methods. Six dampers (2 piezoelectric active members, 4 viscous dampers), placed in three different regions of the structure, produced up to 26 dB attenuation in target modes. The combined control strategy in which the JPL damping methods contributed local control action and the LaRC control scheme provided global control action, produced and overall control scheme with increased stability margins and improved performance. This paper presents an overview of the technologies contributed from the two centers, the strategies used to combine them, and results demonstrating the success of the damping and cooperative control efforts.

Neat, Gregory W.; O'Brien, John F.; Lurie, Boris J.; Garnica, Angel; Belvin, W. K.; Sulla, Jeff; Won, John

1992-01-01

217

iPads in the Science Laboratory: Experience in Designing and Implementing a Paperless Chemistry Laboratory Course  

ERIC Educational Resources Information Center

In the fall of 2012, 20 General Chemistry Honors students at the University of New Haven were issued the new iPad 3 to incorporate these devices both in the classroom and the laboratory. This paper will focus on the integration of the iPad into the laboratory curriculum while creating a paperless experience, an environment where no paper would…

Hesser, Tiffany L.; Schwartz, Pauline M.

2013-01-01

218

Bone conduction experiments in humans - a fluid pathway from bone to ear.  

PubMed

Animal experiments in this laboratory have led to the suggestion that a major pathway in bone conduction stimulation to the inner ear is via the skull contents (brain and CSF). This hypothesis was now tested in humans. Auditory nerve brainstem evoked responses could be recorded in neonates to bone conduction stimulation over the fontanelle and audiometric responses were obtained in neurosurgical patients with the bone vibrator on the skin over a craniotomy. There were no differences in threshold between these responses and those obtained to bone conduction stimulation over skull bone in the same subjects. Audiometric thresholds in response to bone vibrator stimulation of the eye (a 'natural craniotomy') were no different from those to bone stimulation delivered to several sites on the head. Thus there is no need to vibrate bone in order to obtain 'bone conduction' responses. Bone vibrator thresholds to stimulation at the head region with thinnest bone (temporal) were better than those to stimulation at the forehead region which has much thicker bone, implying that the vibrations penetrate the skull at the site of the vibrator. In addition, the magnitude of vibration (acceleration) measured at various sites around the head in response to bone vibrator stimulation at a fixed point on the forehead generally decreased with distance from the point of vibration. Therefore it seems that the vibrations produced by a bone vibrator at a point on the head are also able to penetrate the skull, setting up audio-frequency pressures in the CSF which spread by fluid communications to the inner ear fluids, exciting the ear. PMID:10913886

Sohmer, H; Freeman, S; Geal-Dor, M; Adelman, C; Savion, I

2000-08-01

219

Summary of scientific results. [experiments conducted on lunar surface during Apollo 17 flight  

NASA Technical Reports Server (NTRS)

The accomplishments of the Apollo 17 flight are summarized. The basic objective of the mission was to sample basin-rim highland material and adjacent mare material and to investigate the geological evolutionary relationship between these two major units. The lunar experiments which were conducted include: (1) lunar field geology, (2) surface electrical experiments, (3) lunar traverse gravimeter experiments, (4) lunar seismic profiling experiment, (5) lunar ejecta and meteorites experiment, (6) analysis of lunar atmosphere composition, and (7) heat flow experiments.

Parker, R. A.

1973-01-01

220

Laboratory experiments on ultrasonic wave attenuation in partially frozen brines  

NASA Astrophysics Data System (ADS)

In order to estimate the amount of methane hydrates (MHs) which form in marine sediments at water depths greater than a few hundred meters, using not only velocity information but also attenuation information can provide much more information about MH-bearing sediments. While the presence of MH increases seismic velocity in the host sediment, recent works on sonic logging data show that sonic waveforms are also significantly affected by the presence of MH. However, the increase of attenuation with increasing velocity is somewhat unintuitive. Thus, it is important to validate these phenomena by experimental study and elucidate the rock physical mechanism responsible for these phenomena. In this study, we conducted laboratory measurements to explain partially the reason for the physically unrealizable phenomenon. The ice generated from brine was assumed to be methane hydrate, namely, partially frozen brine was considered to be as an analogue for a mixture of methane hydrate and water present in the pore space of hydrate bearing sediments. We observed the variations of a transmitted wave with frequency content of 150-1000 kHz through a liquid system to a solid-liquid coexistence system, changing its temperature from 20 to -15 C. The centroid frequency shift technique is adapted to the determination of P-wave attenuation. As a result, P-wave velocity increases up to about 3500 m/s with changing in a solid-liquid coexistence system from a liquid system, while P-wave attenuation increases with changing in a solid-liquid coexistence system from a liquid. Especially in a solid-liquid coexistence system, P-wave attenuation decreases with decreasing unfrozen brine. Our observations indicate that the interaction in a micro scale of the solid and liquid causes the dissipation of transmitted wave energy.

Matsushima, J.; Suzuki, M.; Kato, Y.; Rokugawa, S.

2006-12-01

221

Viscous anisotropy of the partially molten mantle: theory and evidence from laboratory experiments (Invited)  

NASA Astrophysics Data System (ADS)

In partially molten regions of Earth, rock and magma coexist as a two-phase aggregate in which the solid grains of rock form a viscously deformable, permeable matrix. Laboratory experiments that mimic this physical system produce banded patterns of rock/magma distribution. Recent theory for anisotropic viscosity of partially molten aggregates is successful in reproducing these patterns; moreover, it makes novel predictions of sample-scale melt redistribution that are testable against experiments. Here we review the theory and present new experiments that test these predictions; we consider a detailed comparison between theory and experiment. In our theory, viscous anisotropy arises from micro-structural anisotropy through considerations of the microscopic mechanics of grain-boundary diffusion creep. The micro-structural anisotropy arises because deviatoric stresses create a directionally dependent contact area between solid grains. The resulting anisotropic viscosity tensor couples shear and volumetric components of stress/strain rate. This coupling, acting over a gradient in shear stress, causes segregation of liquid and solid. Liquid typically migrates toward higher shear stress, but under specific conditions (i.e., in torsion), the opposite can occur. These predictions provide an opportunity to use laboratory experiments to test and refine the theory. The experiments are conducted in Poiseuille or torsional flow geometry, because unlike simple shear, these flows have sample-scale gradients in shear stress. The experimental samples are aggregates of olivine grains and basaltic melt, with/out chromite to modulate the permeability. This material is deformed at high pressure and temperature, either in a Paterson apparatus (torsion) or through a rigid tube (Poiseuille). In both cases, the olivine-grain size is much smaller than any dimension of the emergent porosity structure. Image-processing of sectioned samples quantifies the segregation of magma that occurred over the course of an experiment. We compare these results with theory and discuss implications our understanding of the rheology of partially molten mantle.

Katz, R. F.; Qi, C.; Takei, Y.; Kohlstedt, D. L.

2013-12-01

222

Crack-Detection Experiments on Simulated Turbine Engine Disks in NASA Glenn Research Center's Rotordynamics Laboratory  

NASA Technical Reports Server (NTRS)

The development of new health-monitoring techniques requires the use of theoretical and experimental tools to allow new concepts to be demonstrated and validated prior to use on more complicated and expensive engine hardware. In order to meet this need, significant upgrades were made to NASA Glenn Research Center s Rotordynamics Laboratory and a series of tests were conducted on simulated turbine engine disks as a means of demonstrating potential crack-detection techniques. The Rotordynamics Laboratory consists of a high-precision spin rig that can rotate subscale engine disks at speeds up to 12,000 rpm. The crack-detection experiment involved introducing a notch on a subscale engine disk and measuring its vibration response using externally mounted blade-tip-clearance sensors as the disk was operated at speeds up to 12 000 rpm. Testing was accomplished on both a clean baseline disk and a disk with an artificial crack: a 50.8-mm- (2-in.-) long introduced notch. The disk s vibration responses were compared and evaluated against theoretical models to investigate how successful the technique was in detecting cracks. This paper presents the capabilities of the Rotordynamics Laboratory, the baseline theory and experimental setup for the crack-detection experiments, and the associated results from the latest test campaign.

Woike, Mark R.; Abdul-Aziz, Ali

2010-01-01

223

Gas hydrate dissolution rates quantified with laboratory and seafloor experiments  

NASA Astrophysics Data System (ADS)

Methane hydrates are stable at high pressure, low temperature, and saturated methane concentrations. However, natural hydrates exist at the seafloor where methane concentrations are well below saturation. Under such conditions, hydrate outcrops should shrink rapidly as they dissolve into the surrounding seawater. However, some natural hydrate outcrops have been observed for years undergoing little to no visible signs of change. Further, hydrate dissolution rates vary greatly among sites where changes have been observed. In this study, we perforated a natural hydrate outcrop on the seafloor of the Gulf of Mexico and measured the expansion of the hole after 30 days. From the rate of volume loss, we calculated a dissolution rate of 15 cm y-1. This rate is nearly an order of magnitude slower than hydrate dissolution rates observed in the Northern Cascadia Margin. We hypothesized that crystal structure influences hydrate dissolution rates and that the variability observed in in situ hydrate dissolution is caused by different hydrate structures. To test this hypothesis, we measured methane hydrate (structure I) and propane hydrate (structure II) dissolution rates in a series of laboratory experiments. Hydrates were formed in a pressure vessel and maintained at pressure and temperature conditions conducive to hydrate stability. After formation, the gas source was removed. Dissolution rates were calculated by measuring the increase in the dissolved gas concentration over time. Structure I (methane) hydrate dissolved at an average rate of 5.2 ± 2.5 mM CH4 d-1. Structure II (propane) hydrate dissolved at an average rate of 0.3 ± 0.2 mM C3H8 d-1. The ratio of these dissolution rates was proportional to the ratio of methane and propane solubilities under the experimental conditions. This suggests that dissolution rates in our experiments were diffusion-controlled and not influenced by differences in the crystal structure. We propose that natural contaminants such as oils or biofilms may have slowed the dissolution rate of the hydrate we observed in the Gulf of Mexico.

Lapham, Laura L.; Wilson, Rachel M.; MacDonald, Ian R.; Chanton, Jeffrey P.

2014-01-01

224

Oscillating load-induced acoustic emission in laboratory experiment  

USGS Publications Warehouse

Spatial and temporal patterns of acoustic emission (AE) were studied. A pre-fractured cylinder of granite was loaded in a triaxial machine at 160 MPa confining pressure until stick-slip events occurred. The experiments were conducted at a constant strain rate of 10?7 s?1 that was modulated by small-amplitude sinusoidal oscillations with periods of 175 and 570 seconds. Amplitude of the oscillations was a few percent of the total load and was intended to simulate periodic loading observed in nature (e.g., earth tides or other sources). An ultrasonic acquisition system with 13 piezosensors recorded acoustic emissions that were generated during deformation of the sample. We observed a correlation between AE response and sinusoidal loading. The effect was more pronounced for higher frequency of the modulating force. A time-space spectral analysis for a “point” process was used to investigate details of the periodic AE components. The main result of the study was the correlation of oscillations of acoustic activity synchronized with the applied oscillating load. The intensity of the correlated AE activity was most pronounced in the “aftershock” sequences that followed large-amplitude AE events. We suggest that this is due to the higher strain-sensitivity of the failure area when the sample is in a transient, unstable mode. We also found that the synchronization of AE activity with the oscillating external load nearly disappeared in the period immediately after the stick-slip events and gradually recovered with further loading.

Ponomarev, Alexander; Lockner, David A.; Stroganova, S.; Stanchits, S.; Smirnov, V.

2010-01-01

225

An "in Silico" DNA Cloning Experiment for the Biochemistry Laboratory  

ERIC Educational Resources Information Center

This laboratory exercise introduces students to concepts in recombinant DNA technology while accommodating a major semester project in protein purification, structure, and function in a biochemistry laboratory for junior- and senior-level undergraduate students. It is also suitable for forensic science courses focused in DNA biology and advanced…

Elkins, Kelly M.

2011-01-01

226

Testing laboratory methods to determine the anisotropy of saturated hydraulic conductivity in a sandy–loam soil  

Microsoft Academic Search

Anisotropy, a (the log of the ratio of horizontal to vertical conductivity, log10(Kh\\/Kv)), of saturated soil hydraulic conductivity, Ks, affects transport processes in soil but is not routinely measured, probably because practical and validated methods are lacking. The objective of this investigation was to determine the effects of different constant-head laboratory and sampling procedures on anisotropy of saturated hydraulic conductivity

V. Bagarello; S. Sferlazza; A. Sgroi

2009-01-01

227

Recording the PHILAE Touchdown using CASSE: Laboratory Experiments  

NASA Astrophysics Data System (ADS)

The landing of Philae on comet 67P/Churyumov-Gerasimenko is scheduled for November 11, 2014. Its landing feet house the triaxial acceleration sensors of CASSE (Comet Acoustic Surface Sounding Experiment) which will thus be the first sensors to be in mechanical contact with the cometary surface. It is planned that CASSE will be in listening mode to record the deceleration of the lander by the collision with the comet. The analysis of this data will not only support an engineering analysis of the landing process itself but also yield information about the mechanical properties of the comet's surface. Here, we describe a series of controlled landings of a lander model. The tests were conducted in the Landing & Mobility Test Facility (LAMA) of the DLR Institute of Space Systems in Bremen, Germany, where an industrial robot can be programmed to move landers or rovers along predefined paths and under simulated low gravity. The qualification model of the Philae landing gear was used in the tests. It consists of three legs manufactured of carbon fiber and metal joints. Attached to each leg is a foot with two soles and a mechanically driven ice screw to secure the lander on the comet. The right one of these soles, if viewed from the outside towards the lander body, houses a Brüel & Kjaer DeltaTron 4506 triaxial piezoelectric accelerometer as used on the spacecraft. Orientation of the three axes was such that the X-axis of the accelerometer points downwards while the Y and Z axes are horizontal. This somewhat uncommon orientation was necessary due to the position of the electric connector on the 4506. Data was recorded at a sampling rate of 8.2 kHz for a duration of 2 s. Touchdown measurements were conducted on three types of ground with different landing velocities. Landings with low velocities were carried out on the concrete floor of the LAMA to determine the stiffness of the landing gear based on the deceleration data measured with the accelerometer. Landings on fine-grained quartz sand and on a Mars soil simulant (brand names Wf34 and MSS-D, respectively) allow quantifying the changes of the deceleration data due to interaction with the soil. The elastic moduli of the soils that were inverted from the accelerometer data agree well with data obtained by ultrasonic time-of-flight measurements. To this end, the lander structure was viewed in a simplified way as a mass-spring system coupled to the soil by a contact spring whose stiffness is determined by elastic moduli of the soil and the contact radius.

Knapmeyer, Martin; Faber, Claudia; Tune, Jean-Baptiste; Arnold, Walter; Witte, Lars; Schröder, Silvio; Roll, Reinhard; Chares, Bernd; Fischer, Hans-Herbert; Möhlmann, Diedrich; Seidensticker, Klaus

2014-05-01

228

Laboratory Experiment for the Transient Response of a Stirred Vessel.  

ERIC Educational Resources Information Center

Provides background information, apparatus needed, and procedures for an experiment to measure transient response of a stirred vessel. The inexpensive apparatus can be used for two different experiments, reducing cost per experiment. Both experiments use salt dilution as the method of demonstration. (Author/JN)

Noble, R. D.; And Others

1983-01-01

229

The 5th Annual NASA Spacecraft Control Laboratory Experiment (SCOLE) Workshop, part 2  

NASA Technical Reports Server (NTRS)

A collection of papers from the workshop are presented. The topics addressed include: the modeling, systems identification, and control synthesis for the Spacecraft Control Laboratory Experiment (SCOLE) configuration.

Taylor, Lawrence W., Jr. (compiler)

1990-01-01

230

Experiments On Buoyant Plume Dispersion In A Laboratory Convection Tank  

NASA Astrophysics Data System (ADS)

Plume dispersion in the convective boundary layer (CBL) is investigated experimentally in a laboratory convection tank. The focusis on highly-buoyant plumes that loft near or become trapped in the CBL capping inversion and resistdownward mixing. Such plumes are defined by dimensionless buoyancy fluxes F* 0.1, where F* = Fb/(U w* 2 zi), Fb is the stack buoyancy flux,U is the mean wind speed, w* is the convective velocity scale, and zi is the CBL depth. The aim is to obtain statistically-reliable mean (C) and root-mean-square (rms, c) concentration fields as a function of F* and the dimensionless distance X = w*x/(U zi), where x is the distance downstream of the source.

The experiments reveal the following mainresults: (1) For 3 X 4and F* 0.1, the crosswind-integrated concentration (CWIC) fields exhibit distinctly uniform profiles below zi with a CWIC maximum aloft, in contrast to the nonuniform profiles obtained earlier by Willis and Deardorff. (2) The lateral dispersion (y) variation with X is consistent with Taylor's theory for * 0.1 and a buoyancy-enhanced dispersion, y/zi F* 1/3X2/3, forF* = 0.2 and 0.4. (3) The entrapment, the plume fraction above zi, has a mean (E) that follows a systematic variationwith X and F*, and a variability (e/E) that is broad ( 0.3 to 2) near the source but subsides to 0.25 far downstream. (4) Vertical profiles of the concentration fluctuation intensity (c/C) are uniform for z < zi and X > 1.5, but exhibit significant increases: (a) at the surface and close to the source (X 1.5), and(b) in the entrainment zone. (5) The cumulative distribution functions (CDFs) of the scaled concentration fluctuations (c/c) separate into mixed-layer and entrainment-layer CDFs for X 2, with the mixed-layer group collapsing to a single distribution independent of z.

Weil, Jeffrey C.; Snyder, William H.; Lawson, Robert E.; et al.

231

Research and Laboratory Instruction--An Experiment in Teaching  

ERIC Educational Resources Information Center

Describes an attempt to incorporate research into laboratory work in an introductory ecology class and a senior seminar. The investigation involves the examination of rhythms of food consumption and circadian activities in humans. (GS)

Kramm, Kenneth R.

1976-01-01

232

Remote Detection of Moisture Stress: Field and Laboratory Experiments.  

National Technical Information Service (NTIS)

The relationship between the spectral properties of leaves and the water status of leaves from three crop species was studied under laboratory conditions. The wavelength region examined was from 800 to 2,600 millimicns. Leaf reflectivity and leaf adsorpti...

R. E. Carlson

1971-01-01

233

Using Pneumatics to Perform Laboratory Hydraulic Conductivity Tests on Gravel with Underdamped Responses  

NASA Astrophysics Data System (ADS)

A permeameter has been designed and built to perform laboratory hydraulic conductivity tests on various kinds of gravel samples with hydraulic conductivity values ranging from 0.1 to 1 m/s. The tests are commenced by applying 200 Pa of pneumatic pressure to the free surface of the water column in a riser connected above a cylinder that holds large gravel specimens. This setup forms a permeameter specially designed for these tests which is placed in a barrel filled with water, which acts as a reservoir. The applied pressure depresses the free surface in the riser 2 cm until it is instantly released by opening a ball valve. The water then flows through the base of the cylinder and the specimen like a falling head test, but the water level oscillates about the static value. The water pressure and the applied air pressure in the riser are measured with vented pressure transducers at 100 Hz. The change in diameter lowers the damping frequency of the fluctuations of the water level in the riser, which allows for underdamped responses to be observed for all tests. The results of tests without this diameter change would otherwise be a series of critically damped responses with only one or two oscillations that dampen within seconds and cannot be evaluated with equations for the falling head test. The underdamped responses oscillate about the static value at about 1 Hz and are very sensitive to the hydraulic conductivity of all the soils tested. These fluctuations are also very sensitive to the inertia and friction in the permeameter that are calculated considering the geometry of the permeameter and verified experimentally. Several gravel specimens of various shapes and sizes are tested that show distinct differences in water level fluctuations. The friction of the system is determined by calibrating the model with the results of tests performed where the cylinder had no soil in it. The calculation of the inertia in the response of the water column for the typical testing setup was also verified by performing tests without soil. The friction coefficient of the cylinder base below the specimen where the water enters and exits throughout the test has a minor loss which is determined by analyzing these results. The hydraulic conductivity is then calculated by calculating the friction of the system and subtracting the friction loss from the frictional component of the damping frequency calibrated to the measured data for each test. This allows for a very precise and accurate calculation of the hydraulic conductivity of the soil tested because the closed form analytical model developed and used considers the underdamped responses which fit to the measured data unique to every test more easily than any other method. The average error in predicting the head values for preliminary results is 1 mm, or about 4% of the initial displacement for all tests.

Judge, A. I.

2011-12-01

234

Some More Simple Laser Experiments for the Undergraduate Laboratory  

ERIC Educational Resources Information Center

Describes three elementary optics experiments using a laser instead of conventional light sources. Experiments illustrate the Fresnel-Arago law, elliptical polarization, double refraction and polarization in calcite, and interference by a Fresnel biprism. Because of the high intensity of the laser beam, these experiments lend themselves very well…

Yap, F. Y.

1969-01-01

235

Sodium concentration measurement during hemodialysis through ion-exchange resin and conductivity measure approach: in vitro experiments.  

PubMed

Sodium measurement during hemodialysis treatment is important to preserve the patient from clinical events related to hypo- or hyper-natremia Usually, sodium measurement is performed through laboratory equipment which is typically expensive, and requires manual intervention. We propose a new method, based on conductivity measurement after treatment of dialysate solution through ion-exchange resin. To test this method, we performed in vitro experiments. We prepared 40 ml sodium chloride (NaCl) samples at 280, 140, 70, 35, 17.5, 8.75, 4.375 mEq/l, and some "mixed samples", i.e., with added potassium chloride (KCl) at different concentrations (4.375-17.5 mEq/l), to simulate the confounding factors in a conductivity-based sodium measurement. We measured the conductivity of all samples. Afterwards, each sample was treated for 1 min with 1 g of Dowex G-26 resin, and conductivity was measured again. On average, the difference in the conductivity between mixed samples and corresponding pure NaCl samples (at the same NaCl concentration) was 20.9%. After treatment with the exchange resin, it was 14.7%, i.e., 42% lower. Similar experiments were performed with calcium chloride and magnesium chloride as confounding factors, with similar results. We also performed some experiments on actual dialysate solution during hemodialysis sessions in 15 patients, and found that the correlation between conductivity measures and sodium concentration improved after resin treatment (R=0.839 before treatment, R=0.924 after treatment, P<0.0001). We conclude that ion-exchange resin treatment coupled with conductivity measures may improve the measurement of sodium compared to conductivity measures alone, and may become a possible simple approach for continuous and automatic sodium measurement during hemodialysis. PMID:23844253

Tura, Andrea; Sbrignadello, Stefano; Mambelli, Emanuele; Ravazzani, Paolo; Santoro, Antonio; Pacini, Giovanni

2013-01-01

236

Fractal analysis of the hydraulic conductivity on a sandy porous media reproduced in a laboratory facility.  

NASA Astrophysics Data System (ADS)

The complexity characterization of the porous media structure, in terms of the "pore" phase and the "solid" phase, can be carried out by means of the fractal geometry which is able to put in relationship the soil structural properties and the water content. It is particularly complicated to describe analytically the hydraulic conductivity for the irregularity of the porous media structure. However these can be described by many fractal models considering the soil structure as the distribution of particles dimensions, the distribution of the solid aggregates, the surface of the pore-solid interface and the fractal mass of the "pore" and "solid" phases. In this paper the fractal model of Yu and Cheng (2002) and Yu and Liu (2004), for a saturated bidispersed porous media, was considered. This model, using the Sierpinsky-type gasket scheme, doesn't contain empiric constants and furnishes a well accord with the experimental data. For this study an unconfined aquifer was reproduced by means of a tank with a volume of 10 Ã- 7 Ã- 3 m3, filled with a homogeneous sand (95% of SiO2), with a high percentage (86.4%) of grains between 0.063mm and 0.125mm and a medium-high permeability. From the hydraulic point of view, 17 boreholes, a pumping well and a drainage ring around its edge were placed. The permeability was measured utilizing three different methods, consisting respectively in pumping test, slug test and laboratory analysis of an undisturbed soil cores, each of that involving in the measurement a different support volume. The temporal series of the drawdown obtained by the pumping test were analyzed by the Neuman-type Curve method (1972), because the saturated part above the bottom of the facility represents an unconfined aquifer. The data analysis of the slug test were performed by the Bouwer & Rice (1976) method and the laboratory analysis were performed on undisturbed saturated soil samples utilizing a falling head permeameter. The obtained values either of the fractal dimension of the area of the pores (Df) or of the fractal dimension of capillary tortuosity (DT), very similar to those reported in literature (Yu and Cheng, 2002; Yu and Liu, 2004; Yu, 2005) and falling in the range of definition (1 < Df < 2), resulted very close to those carried out in a previous study performed on the same apparatus but with a limited number of values (De Bartolo et al., in review). In fact in the present study the laboratory analysis were performed on other 10 undisturbed soil samples and moreover three new values of slug test and 12 new of pumping test were considered. Moreover the trend of DT growing with the scale length (L) was confirmed, as well as the invariability of, due to the homogeneity of the considered porous media. The linear scaling law of the permeability (k) close to scale length was investigated furnishing more reliable results. However for a better definition of a law of scale for Df, DT and k several number of scale length are need and a greater number of experimental data should be carried out. For this purpose the considered experimental apparatus is limited from its restricted dimensions and geometric bounds; therefore further investigations in experimental field are desirable. Bibliografy Bouwer, H. & Rice, R. C. 1976. A Slug Test for Hydraulic Conductivity of Unconfined Aquifers With Completely or Partially Penetrating Wells, Water Resources Research, 12(3). De Bartolo, S., Fallico, C., Straface, S., Troisi, S. & Veltri M. (in review). Scaling of the hydraulic conductivity measurements by a fractal analysis on an unconfined aquifer reproduced in a laboratory facility, Geoderma Special Issue 2008. Neuman, S.P. 1972. Theory of flow in unconfined aquifers considering delayed response of the water table, Water Resources Research, 8(4), 1031-1045. Yu, B.M. 2005. Fractal Character for Tortuous Streamtubes in Porous Media, Chin. Phis. Lett., 22(1), 158. Yu, B.M. & Cheng, P. 2002. A Fractal Permeability Model for Bi-Dispersed Porous Media, Int. J. Heat Mas

de Bartolo, S.; Fallico, C.; Straface, S.; Troisi, S.; Veltri, M.

2009-04-01

237

[Brief discussion on experiences from laboratory certification and accreditation on detection of parasitic diseases].  

PubMed

The laboratory certification and accreditation is the development trend of domestic and international laboratories. The National Institute for Parasitic Diseases, Chinese Center for Disease Control and Prevention passed through the site assessment in September 2012 successfully, 26 items in 8 fields declared were all adopted. This article summarizes some work experiences during carrying out the laboratory certification and accreditation. PMID:24490411

Xiong, Yan-Hong; Guan, Ya-Yi; Cao, Jian-Ping; Zheng, Bin; Wang, Yan-Juan; Zhang, Min-Qi; Zhou, Xiao-Jun

2013-12-01

238

The effect of moisture content on radon diffusion through soil: assessment in laboratory and field experiments.  

PubMed

The diffusion of radon through soil is strongly affected by the degree of water saturation of the soil pores. In the present work, a laboratory technique for studying radon diffusion has been developed and applied to determine diffusion coefficients in a sandy loam, containing various amounts of water, from null to saturation. The results indicate that, once the soil pore volume becomes saturated to values above approximately 20%, the diffusion of radon is markedly hampered; the bulk diffusion coefficient drops from 1.2 x 10(-6) to 2 x 10(-9) m2 s(-1) as soil saturation increases from 20 to 90%. The effect of soil moisture was further evaluated in field experiments conducted on soil of the same matrix. Comparison between results obtained by the two methods showed that laboratory studies may provide a good indication of radon diffusion coefficients to be expected in situ. However, values determined in the field were systematically lower than those assessed in the laboratory, illustrating the key role of structural differences between undisturbed and repacked soil. PMID:17293698

Papachristodoulou, C; Ioannides, K; Spathis, S

2007-03-01

239

Laboratory experiments and observations of cyclonic and anticyclonic eddies impinging on an island  

NASA Astrophysics Data System (ADS)

experiments are conducted to investigate the interactions of self-propagating barotropic cyclones and baroclinic anticyclones with an island. Results are interpreted in the context of observations around Okinawa Island, Japan, where ubiquitous arrivals of cyclones and anticyclones on the southeastern side of the island influence the flow around it, thereby impacting both the Ryukyu Current's and the Kuroshio's transport. In the laboratory, baroclinic anticyclones generate a buoyant current that flows clockwise around an island whereas barotropic cyclones generate a counterclockwise current. In both cases, the interaction is governed by conservation of circulation ? around the island, which establishes a balance between the dissipation along the island in contact with the eddy and the dissipation along the island in contact with the generated current. Laboratory results and scaling analysis suggest that the interaction between an anticyclone (cyclone) and Okinawa Island should result in an instantaneous increase (decrease) of the Ryukyu Current transport and a delayed increase (decrease) of the Kuroshio transport. The estimated delays are in good agreement with those obtained with field measurements suggesting that the dynamics at play in the laboratory may be relevant for the flow around Okinawa Island.

Andres, Magdalena; Cenedese, Claudia

2013-02-01

240

An Example of a Laboratory Teaching Experience in a Professional Year (Plan B) Program  

ERIC Educational Resources Information Center

A laboratory teaching experience (L.T.E.) was designed to focus on three teaching behaviors. It was recognized that a behavioral approach to teaching simplified its complexity by isolating specific teaching behaviors. Discusses the development and evaluation of the laboratory teaching experience. (Author/RK)

Miller, P. J.; And Others

1978-01-01

241

Redefining Authentic Research Experiences in Introductory Biology Laboratories and Barriers to Their Implementation  

ERIC Educational Resources Information Center

Incorporating authentic research experiences in introductory biology laboratory classes would greatly expand the number of students exposed to the excitement of discovery and the rigor of the scientific process. However, the essential components of an authentic research experience and the barriers to their implementation in laboratory classes are…

Spell, Rachelle M.; Guinan, Judith A.; Miller, Kristen R.; Beck, Christopher W.

2014-01-01

242

Capillary Electrophoresis Analysis of Cations in Water Samples: An Experiment for the Introductory Laboratory  

ERIC Educational Resources Information Center

Capillary electrophoresis is gradually working its way into the undergraduate laboratory curriculum. Typically, experiments utilizing this newer technology have been introduced into analytical or instrumental courses. The authors of this article have introduced an experiment into the introductory laboratory that utilizes capillary electrophoresis…

Pursell, Christopher J.; Chandler, Bert; Bushey, Michelle M.

2004-01-01

243

Summary of recent experiments on focusing of target-normal-sheath-accelerated proton beam with a stack of conducting foilsa)  

NASA Astrophysics Data System (ADS)

We present a summary of recent experiments on focusing of laser target-normal-sheath-accelerated (TNSA) proton beam with a stack of thin conducting foils. The experiments were performed using the Phelix laser (GSI-Darmstadt) and the Titan laser, Lawrence Livermore National Laboratory. The phenomena consistent with self-collimation (or weak self-focusing) of TNSA protons were experimentally observed for the first time at the Phelix laser user facility, in a specially engineered structure ("lens") consisting of a stack of 300 thin aluminum foils separated by 50 ?m vacuum gaps. Follow up experiments using the Titan laser obtained results consistent with the collimation/focusing observed in the initial experiments using the Phelix. The Titan experiments employed improved, 25 ?m- and 50 ?m-gap targets and the new fine mesh diagnostic. All the experiments were carried out in a "passive environment," i.e., no external fields were applied, and no neutralization plasma or injection of secondary charged particles was imposed. A plausible interpretation of the observed phenomena is that the combination of magnetic self-pinch forces generated by the beam current together with the simultaneous reduction of the repulsive electrostatic forces due to the conducting foils inhibits radial expansion of the beam.

Ni, P. A.; Alexander, N.; Barnard, J. J.; Lund, S. M.

2014-05-01

244

Ground-based laboratory atomic oxygen calibration experiments  

Microsoft Academic Search

Existing devices and analysis techniques for the monitoring of space and laboratory simulated Atomic Oxygen (AO) environments have been investigated and improved to enable more accurate and reliable measurement and calibration of AO flux and fluences than previously possible. This research was based on experimental work carried out in a ground based AO facility designed to simulate the low Earth

Jeremy Stephen Matcham

1998-01-01

245

Some laboratory experiments on shear wave propagation in unconsolidated sands  

Microsoft Academic Search

With the recent development of a method to transmit shear wave energy through laboratory unconsolidated sediments, an important new era of research on the dynamic properties of sediments has just begun. This, in time, will complement the vast amount of compressional wave data existent in the literature and provide the researcher with a very important tool to aid in the

Ian W. Horn

1980-01-01

246

Operational experience on the Brookhaven National Laboratory Accelerator Test Facility  

SciTech Connect

Brookhaven National Laboratory Accelerator Test Facility is a laser-electron linear accelerator complex designed to provide high brightness beams for testing of advanced acceleration concepts and high power pulsed photon sources. Results of electron beam parameters attained during the commissioning of the nominally 45 MeV energy machine are presented.

Batchelor, K.; Babzien, M.; Ben-Zvi, I. [and others

1994-09-01

247

Integrated laboratory scale demonstration experiment of SI cycle  

Microsoft Academic Search

The Sulfur Iodine thermochemical cycle for the production of hydrogen is one of the promising approaches for use with next generation high temperature advanced nuclear reactors. Within the framework of an international collaboration (I-NERI project) between the American DOE and the French CEA, the development of a laboratory scale hydrogen production loop using the sulfur iodine cycle will be performed

Jean Leybros; Jean Duhamet; Denis Ode; Nicolas Pons; Philippe Dehaudt; Michel Boidron; Max Helie

2007-01-01

248

The Nature of Laboratory Learning Experiences in Secondary Science Online  

ERIC Educational Resources Information Center

Teaching science to secondary students in an online environment is a growing international trend. Despite this trend, reports of empirical studies of this phenomenon are noticeably missing. With a survey concerning the nature of laboratory activities, this study describes the perspective of 35-secondary teachers from 15-different U.S. states who…

Crippen, Kent J.; Archambault, Leanna M.; Kern, Cindy L.

2013-01-01

249

Equipment qualification testing evaluation experiences at Sandia National Laboratories  

Microsoft Academic Search

The USNRC has sponsored a number of programs at Sandia National Laboratories specifically addressing safety-related equipment qualification. The most visible of these programs has been the Qualification Testing Evaluation (QTE) program. Other relevant programs have included the Equipment Qualification Methodology Research Test program (CAP). Over a ten year period these programs have collectively tested numerous types of safety-related equipment. Some

L. D. Bustard; F. J. Wyant; L. L. Bonzon; K. T. Gillen

1986-01-01

250

Students' Experience in a General Chemistry Cooperative Problem Based Laboratory  

ERIC Educational Resources Information Center

Most educators and scientists would agree that science laboratory instruction has the potential of developing science practices fundamental to achieving scientific literacy. However, there is scant evidence to support that this potential is realized, particularly in tertiary level education. This paper reports qualitative results from a sequential…

Sandi-Urena, Santiago; Cooper, Melanie M.; Gatlin, Todd A.; Bhattacharyya, Gautam

2011-01-01

251

Experimenting from a Distance--Remotely Controlled Laboratory (RCL)  

ERIC Educational Resources Information Center

The use of computers and multimedia, as well as the World Wide Web and new communication technologies, allows new forms of teaching and learning such as distance learning, blended learning, use of virtual libraries and many more. The herewith discussed remotely controlled laboratory (RCL) project shall offer an additional contribution. The basic…

Grober, Sebastian; Vetter, Martin; Eckert, Bodo; Jodl, Hans-Jorg

2007-01-01

252

Restructuring a General Microbiology Laboratory into an Investigative Experience.  

ERIC Educational Resources Information Center

Describes an investigative laboratory sequence based upon the isolation and characterization of soil bacteria to aid microbiology teachers in providing students with activities that expose them to basic techniques of microbiology as well as demonstrates the scientific process and the experimental analysis of microorganisms. (ZWH)

Deutch, Charles E.

1994-01-01

253

EXPERIMENTS ON BUOYANT PLUME DISPERSION IN A LABORATORY CONVENTION TANK  

EPA Science Inventory

Buoyant plume dispersion in the convective boundary layer (CBL) is investigated experimentally in a laboratory convection tank. The focus is on highly-buoyant plumes that loft near the CBL capping inversion and resist downward mixing. Highly- buoyant plumes are those with dimen...

254

Limits on Lithospheric Stress Imposed by Laboratory Experiments  

Microsoft Academic Search

Laboratory measurements of rock strength provide limiting values of lithospheric stress, provided that one effective principal stress is known. Fracture strengths are too variable to be useful; however, rocks at shallow depth are probably fractured so that frictional strength may apply. A single linear friction law, termed Byedee's law, holds for all materials except clays, to pressures of more than

W. F. Brace; D. L. Kohlstedt

1980-01-01

255

Transient groundwater chemistry near a river: Effects on U(VI) transport in laboratory column experiments  

NASA Astrophysics Data System (ADS)

In the 300 Area of a U(VI)-contaminated aquifer at Hanford, Washington, USA, inorganic carbon and major cations, which have large impacts on U(VI) transport, change on an hourly and seasonal basis near the Columbia River. Batch and column experiments were conducted to investigate the factors controlling U(VI) adsorption/desorption by changing chemical conditions over time. Low alkalinity and low Ca concentrations (Columbia River water) enhanced adsorption and reduced aqueous concentrations. Conversely, high alkalinity and high Ca concentrations (Hanford groundwater) reduced adsorption and increased aqueous concentrations of U(VI). An equilibrium surface complexation model calibrated using laboratory batch experiments accounted for the decrease in U(VI) adsorption observed with increasing (bi)carbonate concentrations and other aqueous chemical conditions. In the column experiment, alternating pulses of river and groundwater caused swings in aqueous U(VI) concentration. A multispecies multirate surface complexation reactive transport model simulated most of the major U(VI) changes in two column experiments. The modeling results also indicated that U(VI) transport in the studied sediment could be simulated by using a single kinetic rate without loss of accuracy in the simulations. Moreover, the capability of the model to predict U(VI) transport in Hanford groundwater under transient chemical conditions depends significantly on the knowledge of real-time change of local groundwater chemistry.

Yin, Jun; Haggerty, Roy; Stoliker, Deborah L.; Kent, Douglas B.; Istok, Jonathan D.; Greskowiak, Janek; Zachara, John M.

2011-04-01

256

Transient groundwater chemistry near a river: Effects on U(VI) transport in laboratory column experiments  

SciTech Connect

In the 300 Area of a U(VI)-contaminated aquifer at Hanford, Washington, USA, inorganic carbon and major cations, which have large impacts on U(VI) transport, change on an hourly and seasonal basis near the Columbia River. Batch and column experiments were conducted to investigate the factors controlling U(VI) adsorption/desorption by changing chemical conditions over time. Low alkalinity and low Ca concentrations (Columbia River water) enhanced adsorption and reduced aqueous concentrations. Conversely, high alkalinity and high Ca concentrations (Hanford groundwater) reduced adsorption and increased aqueous concentrations of U(VI). An equilibrium surface complexation model calibrated using laboratory batch experiments accounted for the decrease in U(VI) adsorption observed with increasing (bi)carbonate concentrations and other aqueous chemical conditions. In the column experiment, alternating pulses of river and groundwater caused swings in aqueous U(VI) concentration. A multispecies multirate surface complexation reactive transport model simulated most of the major U(VI) changes in two column experiments. The modeling results also indicated that U(VI) transport in the studied sediment could be simulated by using a single kinetic rate without loss of accuracy in the simulations. Moreover, the capability of the model to predict U(VI) transport in Hanford groundwater under transient chemical conditions depends significantly on the knowledge of real-time change of local groundwater chemistry.

Yin, Jun; Haggerty, Roy; Stoliker, Deborah L.; Kent, Douglas B.; Istok, Jonathan D.; Greskowiak, Janek; Zachara, John M.

2011-04-05

257

STAR: Preparing future science and math teachers through authentic research experiences at national laboratories  

NASA Astrophysics Data System (ADS)

The STEM Teacher and Researcher (STAR) Program provides 9-week paid summer research experiences at national research laboratories for future science and math teachers. The program, run by the Cal Poly Center for Excellence in Science and Mathematics Education (CESaME) on behalf of the entire California State University (CSU) System, has arranged 290 research internships for 230 STEM undergraduates and credential candidates from 43 campuses over the past 6 years. The program has partnered with seven Department of Energy labs, four NASA centers, three NOAA facilities, and the National Optical Astronomy Observatory (NOAO). Primary components of the summer experience include a) conducting research with a mentor or mentor team, b) participating in weekly 2-3 hour workshops focused on translating lessons learned from summer research into classroom practice, and c) presenting a research poster or oral presentation and providing a lesson plan linked to the summer research experience. The central premise behind the STAR Program is that future science and math teachers can more effectively prepare the next generation of science, math, and engineering students if they themselves have authentic experiences as researchers.

Keller, John; Rebar, Bryan

2012-11-01

258

Apparent soil electrical conductivity: applications for designing and evaluating field-scale experiments  

Microsoft Academic Search

On-farm field-scale research has become increasingly common with the advent of new technologies. While promoting a realistic systems perspective, field-scale experiments do not lend themselves to the traditional design concepts of replication and blocking. Previously, a farm-scale dryland experiment in northeastern Colorado was conducted to evaluate apparent electrical conductivity (ECa) classification (within-field blocking) as a basis for estimating plot-scale experimental

C. K. Johnson; K. M. Eskridge; D. L. Corwin

2005-01-01

259

Decision-making under uncertainty: results from an experiment conducted at EGU 2012  

NASA Astrophysics Data System (ADS)

Do probabilistic forecasts lead to better decisions? At the EGU General Assembly 2012, we conducted a laboratory-style experiment to address this question. Several cases of flood forecasts and a choice of actions to take were presented as part of a game to participants, who acted as decision makers. Participants were prompted to make decisions when forecasts were provided with and without uncertainty information. They had to decide whether to open or not a gate which was the inlet of a retention basin designed to protect a town. The rules were such that: if they decided to open the gate, the retention basin was flooded and the farmers in this basin demanded a compensation for flooding their land; if they decided not to open the gate and a flood occurred on the river, the town was flooded and they had to pay a fine to the town. Participants were encouraged to keep note of their individual decisions in a worksheet. About 100 worksheets were collected at the end of the game and the results of their evaluation are presented here. In general, they show that decisions are based on a combination of what is displayed by the expected (forecast) value and what is given by the uncertainty information. In the absence of uncertainty information, decision makers are compelled towards a more risk-averse attitude. Besides, more money was lost by a large majority of participants when they had to make decisions without uncertainty information. Limitations of the experiment setting are discussed, as well as the importance of the development of training tools to increase effectiveness in the use of probabilistic predictions to support decisions under uncertainty.

Ramos, Maria-Helena; van Andel, Schalk Jan; Pappenberger, Florian

2013-04-01

260

Reactions of Thiocyanate Ions with Acid: A Laboratory Experiment.  

ERIC Educational Resources Information Center

Background information, procedures, and typical results are provided for a three-part experiment involving reactions of potassium thiocynate (KNCS) with sulfuric acid. The experiment represents the final stage of structured work prior to students' research projects during their final year. (JM)

Glidewell, Christopher; And Others

1984-01-01

261

A Thin Layer Chromatography Laboratory Experiment of Medical Importance  

ERIC Educational Resources Information Center

A thin layer chromatography experiment of medical importance is described. The experiment involves extraction of lipids from simulated amniotic fluid samples followed by separation, detection, and scanning of the lecithin and sphingomyelin bands on TLC plates. The lecithin-to-sphingomyelin ratio is calculated. The clinical significance of this…

Sharma, Loretta; Desai, Ankur; Sharma, Ajit

2006-01-01

262

Microcomputer-Based Digital Signal Processing Laboratory Experiments.  

ERIC Educational Resources Information Center

Describes a system (Apple II microcomputer interfaced to flexible, custom-designed digital hardware) which can provide: (1) Fast Fourier Transform (FFT) computation on real-time data with a video display of spectrum; (2) frequency synthesis experiments using the inverse FFT; and (3) real-time digital filtering experiments. (JN)

Tinari, Jr., Rocco; Rao, S. Sathyanarayan

1985-01-01

263

A Spectroscopic-Based Laboratory Experiment for Protein Conformational Studies  

ERIC Educational Resources Information Center

This article describes a practical experiment for teaching basic spectroscopic techniques to introduce the topic of protein conformational change to students in the field of molecular biology, biochemistry, or structural biology. The spectroscopic methods employed in the experiment are absorbance, for protein concentration measurements, and…

Ramos, Carlos Henrique I.

2004-01-01

264

Laboratory Experiment of Magnetic Reconnection between Merging Flux Tubes with Strong Guide FIeld  

NASA Astrophysics Data System (ADS)

Magnetic reconnection governs variety of energy release events in the universe, such as solar flares, geomagnetic substorms, and sawtooth crash in laboratory nuclear fusion experiments. Differently from the classical steady reconnection models, non-steady behavior of magnetic reconnection is often observed. In solar flares, intermittent enhancement of HXR emission is observed synchronously with multiple ejection of plammoids [1]. In laboratory reconnection experiments, the existence of the guide field, that is perpendicular to the reconnection field, makes significant changes on reconnection process. Generally the guide field will slow down the reconnection rate due to the increased magnetic pressure inside the current sheet. It also brings about asymmetric structure of the separatrices or effective particle acceleration in collisionless conditions. We have conducted laboratory experiments to study the behavior of the guide-field magnetic reconnection using plasma merging technique (push reconnection). Under substantial guide field even larger than the reconnection field, the reconnection generally exhibits non-steady feature which involves intermittent detachment of X-point and reconnection current center[2]. Transient enhancement of reconnection rate is observed simultaneously with the X-point motion[3]. We found two distinct phenomena associated with the guide-field non-steady reconnection. The one is the temporal and localized He II emission from X-point region, suggesting the production of energetic electrons which could excite the He ions in the vicinity of the X-point. The other is the excitation of large-amplitude electromagnetic waves which have similar properties with kinetic Alfven waves, whose amplitude show positive correlation with the enhancement of the reconnection electric field[4]. Electron beam instability caused by the energetic electrons accelerated to more than twice of the electron thermal velocity could be a potential driver of the monochromatic magnetic fluctuations. In conclusion, the laboratory guide field reconnection experiments showed some unique features such as ejection of current sheet, localized enhancement of emission, and excitation of low frequency waves, suggesting intermittent fast reconnection mechanism with significant electron acceleration. [1] N. Nishizuka et al., Astrophysical J. 711, 1062 (2010). [2] Y. Ono et al., Phys. Plasmas 18, 111213 (2011). [3] M. Inomoto et al., Plasma and Fusion Res. 8, 2401112 (2013). [4] M. Inomoto et al., Phys. Plasmas 20, 061209 (2013).

Inomoto, M.; Kamio, S.; Kuwahata, A.; Ono, Y.

2013-12-01

265

Laser-driven ICF experiments: Laboratory Report No. 223  

SciTech Connect

Laser irradiation uniformity is a key issue and is treated in some detail. The basic irradiation uniformity requirements and practical ways of achieving these requirements are both discussed, along with two beam-smoothing techniques: induced spatial incoherence (ISI), and smoothing by spectral dispersion (SSD). Experiments to measure and control the irradiation uniformity are also highlighted. Following the discussion of irradiation uniformity, a brief review of coronal physics is given, including the basic physical processes and their experimental signatures, together with a summary of pertinent diagnostics and results from experiments. Methods of determining ablation rates and thermal transport are also described. The hydrodynamics of laser-driven targets must be fully understood on the basis of experiments. Results from implosion experiments, including a brief description of the diagnostics, are presented. Future experiments aimed at determining ignition scaling and demonstrating hydrodynamically equivalent physics applicable to high-gain designs.

McCrory, R.L.

1991-04-01

266

Exploring the Effectiveness of a Field Experience Program in a Pedagogical Laboratory: The Experience of Teacher Candidates  

ERIC Educational Resources Information Center

Researchers argue that teachers' beliefs are the final barrier that prevents technology integration. To affect change in teacher candidates' beliefs of technology integration, we created a pedagogical laboratory as well as a field experience program that operates within the pedagogical laboratory. This article presents a qualitative study of…

Ma, Yuxin; Lai, Guolin; Williams, Doug; Prejean, Louise; Ford, Mary Jane

2008-01-01

267

Property-Transfer Modeling to Estimate Unsaturated Hydraulic Conductivity of Deep Sediments at the Idaho National Laboratory, Idaho  

USGS Publications Warehouse

The unsaturated zone at the Idaho National Laboratory is complex, comprising thick basalt flow sequences interbedded with thinner sedimentary layers. Understanding the highly nonlinear relation between water content and hydraulic conductivity within the sedimentary interbeds is one element in predicting water flow and solute transport processes in this geologically complex environment. Measurement of unsaturated hydraulic conductivity of sediments is costly and time consuming, therefore use of models that estimate this property from more easily measured bulk-physical properties is desirable. A capillary bundle model was used to estimate unsaturated hydraulic conductivity for 40 samples from sedimentary interbeds using water-retention parameters and saturated hydraulic conductivity derived from (1) laboratory measurements on core samples, and (2) site-specific property transfer regression models developed for the sedimentary interbeds. Four regression models were previously developed using bulk-physical property measurements (bulk density, the median particle diameter, and the uniformity coefficient) as the explanatory variables. The response variables, estimated from linear combinations of the bulk physical properties, included saturated hydraulic conductivity and three parameters that define the water-retention curve. The degree to which the unsaturated hydraulic conductivity curves estimated from property-transfer-modeled water-retention parameters and saturated hydraulic conductivity approximated the laboratory-measured data was evaluated using a goodness-of-fit indicator, the root-mean-square error. Because numerical models of variably saturated flow and transport require parameterized hydraulic properties as input, simulations were run to evaluate the effect of the various parameters on model results. Results show that the property transfer models based on easily measured bulk properties perform nearly as well as using curve fits to laboratory-measured water retention for the estimation of unsaturated hydraulic conductivity.

Perkins, Kim S.; Winfield, Kari A.

2007-01-01

268

Chemical composition and acute toxicity in the water after in situ burning--a laboratory experiment.  

PubMed

The chemical composition and toxicity of a water soluble fraction (WSF) of oil versus the underlying water after in situ burning (ISB), has been studied in a laboratory experiment. A system for allowing water sampling after ISB was developed. Seawater samples and oil were collected prior to and immediately after ISB, and chemical analysis was conducted. The chemical characterization of the water showed that the disappearance of water soluble oil components during ISB was insignificant. Acute toxicity tests with the marine copepod Calanus finmarchicus and Microtox® bioassay was performed to establish LC(50)/EC(50) values of the water. The results were compared with regular WAF systems with unburned weathered oil, and indicated no increase in toxicity in the underlying water after ISB. PMID:22112284

Faksness, Liv-Guri; Hansen, Bjørn Henrik; Altin, Dag; Brandvik, Per Johan

2012-01-01

269

Touring the Tomato: A Suite of Chemistry Laboratory Experiments  

PubMed Central

An eight-session interdisciplinary laboratory curriculum has been designed using a suite of analytical chemistry techniques to study biomaterials derived from an inexpensive source such as the tomato fruit. A logical progression of research-inspired laboratory modules serves to “tour” the macroscopic characteristics of the fruit and the submicroscopic properties of its constituent cuticular biopolymers by atomic force microscopy (AFM), UV–visible, and nuclear magnetic resonance (NMR) methods at increasingly detailed molecular levels. The modular curriculum can be tailored for specialty undergraduate courses or summer high school workshops. By applying analytical tools to investigate biopolymers, making connections between molecular and microscale structure, and linking both structural regimes to the functional properties of natural polymers, groundwork is established for further student investigations at the interface of chemistry with biology or chemical engineering.

Sarkar, Sayantani; Chatterjee, Subhasish; Medina, Nancy; Stark, Ruth E.

2013-01-01

270

Laboratory-scale experiments on wind turbine nacelle movement estimation  

NASA Astrophysics Data System (ADS)

The effect of nacelle motion should be considered when calculating the wind speed relative to the wind turbine structure, which is essential in wind turbine control and performance testing. A Kalman filter approach is applied to estimate the nacelle motion of a wind turbine. Information from several accelerometers and strain gauges which are installed on the wind turbine tower is combined with the Kalman filter. An optimization algorithm is used to choose the optimal locations for strain gauge and accelerometer installation. A laboratory-scale experimental rig which mimics the tower and nacelle of the wind turbine is constructed to evaluate the performance of the proposed estimator algorithm. The usefulness of the proposed algorithm is validated by these laboratory-scale experimental results.

Nam, Yoonsu; Yoon, Tai Jun

2009-11-01

271

The plasma dynamics of hypersonic spacecraft: Applications of laboratory simulations and active in situ experiments  

NASA Technical Reports Server (NTRS)

Attempts to gain an understanding of spacecraft plasma dynamics via experimental investigation of the interaction between artificially synthesized, collisionless, flowing plasmas and laboratory test bodies date back to the early 1960's. In the past 25 years, a number of researchers have succeeded in simulating certain limited aspects of the complex spacecraft-space plasma interaction reasonably well. Theoretical treatments have also provided limited models of the phenomena. Several active experiments were recently conducted from the space shuttle that specifically attempted to observe the Orbiter-ionospheric interaction. These experiments have contributed greatly to an appreciation for the complexity of spacecraft-space plasma interaction but, so far, have answered few questions. Therefore, even though the plasma dynamics of hypersonic spacecraft is fundamental to space technology, it remains largely an open issue. A brief overview is provided of the primary results from previous ground-based experimental investigations and the preliminary results of investigations conducted on the STS-3 and Spacelab 2 missions. In addition, several, as yet unexplained, aspects of the spacecraft-space plasma interaction are suggested for future research.

Stone, N. H.; Samir, Uri

1986-01-01

272

Implications of non-equilibrium transport in heterogeneous reactive barrier systems: Evidence from laboratory denitrification experiments  

NASA Astrophysics Data System (ADS)

Organic substrates in reactive barrier systems are often heterogeneous material mixtures with relatively large contrasts in hydraulic conductivity and porosity over short distances. These short-range variations in material properties imply that preferential flow paths and diffusion between regions of higher and lower hydraulic conductivity may be important for treatment efficiency. This paper presents the results of a laboratory column experiment where denitrification is investigated using a heterogeneous reactive substrate (sawdust mixed with sewage sludge). Displacement experiments with a non-reactive solute at three different flow rates are used to estimate transport parameters using a dual porosity non-equilibrium model. Parameter estimation from breakthrough curves produced relatively consistent values for the fraction of the porosity consisting of mobile water (?) and the mass transfer coefficient (?), with average values of 0.27 and 0.42 d - 1 , respectively. The column system removes > 95% of the influent nitrate at low and medium flow, but only 50-75% of the influent nitrate at high flow, suggesting that denitrification kinetics and diffusive mass transfer rates are limiting the degree of treatment at lower hydraulic residence times. Reactive barrier systems containing dual porosity media must therefore consider mass transfer times in their design; this is often most easily accommodated by adjusting flowpath length.

Herbert, Roger B., Jr.

2011-04-01

273

Integrating Computational Chemistry into a Project-Oriented Biochemistry Laboratory Experience: A New Twist on the Lysozyme Experiment  

Microsoft Academic Search

The biochemistry laboratory at many universities is becoming more focused on a project-oriented experience. For example, a single enzyme is chosen and studied throughout the entire semester. A project-oriented laboratory has been adapted and expanded to include computational and carbohydrate chemistry. Egg-white lysozyme was purified and characterized. To expand and update the experiment, a computational module was added in which

Rachel R. Peterson; James R. Cox

2001-01-01

274

Laboratory Experiments for the Investigation of Interstellar Dust Analogues  

NASA Astrophysics Data System (ADS)

A laboratory instrument for the precise, non-destructive determination of the charge and mass of single, well localized and isolated submicron particles under ultra high vacuum conditions is described. A mass resolution of better than 3 cdot 10 ^{-4} is reported. Secondary electron emission is monitored online event by event and used to determine the particles absolute charge state. Future applications for the investigation of gas-grain interaction such as determination of sticking coefficients and sublimation temperatures are discussed.

Schlemmer, S.; Illemann, J.; Wellert, S.; Gerlich, D.

1999-08-01

275

Insights into oil cracking based on laboratory experiments  

Microsoft Academic Search

The objectives of this pyrolysis investigation were to determine changes in (1) oil composition, (2) gas composition and (3) gas carbon isotope ratios and to compare these results with hydrocarbons in reservoirs. Laboratory cracking of a saturate-rich Devonian oil by confined, dry pyrolysis was performed at T=350–450 °C, P=650 bars and times ranging from 24 h to 33 days. Increasing thermal

Ronald J. Hill; Yongchun Tang; Isaac R. Kaplan

2003-01-01

276

Laboratory Experiment of Plasma Flow Around Magnetic Sail  

Microsoft Academic Search

To propel a spacecraft in the direction leaving the Sun, a magnetic sail (MagSail) blocks the hypersonic solar wind plasma\\u000a flow by an artificial magnetic field. In order to simulate the interaction between the solar wind and the artificially deployed\\u000a magnetic field produced around a magnetic sail spacecraft, a laboratory simulator was designed and constructed inside a space\\u000a chamber. As

Ikkoh Funaki; Hidenori Kojima; Hiroshi Yamakawa; Yoshinori Nakayama; Yukio Shimizu

2007-01-01

277

Analyses of internal tides generation and propagation over a Gaussian ridge in laboratory and numerical experiments  

NASA Astrophysics Data System (ADS)

Internal tides are suggested to play a major role in the sustaining of the global oceanic circulation [1][5]. Although the exact origin of the energy conversions occurring in stratified fluids is questioned [2], it is clear that the diapycnal energy transfers provided by the energy cascade of internal gravity waves generated at tidal frequencies in regions of steep bathymetry is strongly linked to the general circulation energy balance. Therefore a precise quantification of the energy supply by internal waves is a crucial step in forecasting climate, since it improves our understanding of the underlying physical processes. We focus on an academic case of internal waves generated over an oceanic ridge in a linearly stratified fluid. In order to accurately quantify the diapycnal energy transfers caused by internal waves dynamics, we adopt a complementary approach involving both laboratory and numerical experiments. The laboratory experiments are conducted in a 4m long tank of the CNRM-GAME fluid mechanics laboratory, well known for its large stratified water flume (e.g. Knigge et al [3]). The horizontal oscillation at precisely controlled frequency of a Gaussian ridge immersed in a linearly stratified fluid generates internal gravity waves. The ridge of e-folding width 3.6 cm is 10 cm high and spans 50 cm. We use PIV and Synthetic Schlieren measurement techniques, to retrieve the high resolution velocity and stratification anomaly fields in the 2D vertical plane across the ridge. These experiments allow us to get access to real and exhaustive measurements of a wide range of internal waves regimes by varying the precisely controlled experimental parameters. To complete this work, we carry out some direct numerical simulations with the same parameters (forcing amplitude and frequency, initial stratification, boundary conditions) as the laboratory experiments. The model used is a non-hydrostatic version of the numerical model Symphonie [4]. Our purpose is not only to test the dynamics and energetics of the numerical model, but also to advance the analysis based on combined wavelet and empirical orthogonal function. In particular, we focus on the study of the transient regime of internal wave generation near the ridge. Our analyses of the experimental fields show that, for fixed background stratification and topography, the evolution of the stratification anomaly strongly depends on the forcing frequency. The duration of the transient regime, as well as the amplitude reached in the stationary state vary significantly with the parameter ?/N (where ? is the forcing frequency, and N is the background Brunt-Väisälä frequency). We also observe that, for particular forcing frequencies, for which the ridge slope matches the critical slope of the first harmonic mode, internal waves are excited both at the fundamental and the first harmonic frequency. Associated energy transfers are finally evaluated both experimentally and numerically, enabling us to highlight the similarities and discrepancies between the laboratory experiments and the numerical simulations. References [1] Munk W. and C. Wunsch (1998): Abyssal recipes II: energetics of tidal and wind mixing Deep-Sea Res. 45, 1977-2010 [2] Tailleux R. (2009): On the energetics of stratified turbulent mixing, irreversible thermodynamics, Boussinesq models and the ocean heat engine controversy, J. Fluid Mech. 638, 339-382 [3] Knigge C., D. Etling, A. Paci and O. Eiff (2010): Laboratory experiments on mountain-induced rotors, Quarterly Journal of the Royal Meteorological Society, in press. [4] Auclair F., C. Estournel, J. Floor, C. N'Guyen and P. Marsaleix, (2009): A non-hydrostatic, energy conserving algorithm for regional ocean modelling. Under revision. [5] Wunsch, C. & R. Ferrari (2004): Vertical mixing, energy and the general circulation of the oceans. Annu. Rev. Fluid Mech., 36:281-314.

Dossmann, Yvan; Paci, Alexandre; Auclair, Francis; Floor, Jochem

2010-05-01

278

Laboratory Exercise A Guided Inquiry Experiment for the Measurement of Activation Energies in the Biophysical Chemistry Laboratory  

Microsoft Academic Search

A laboratory experiment for undergraduate biophysical chemistry is described, in which the acid concen- tration and temperature dependences of the decarboxylation of pyrrole-2-carboxylate are measured using a continuous ultraviolet (UV) spectrophotometric assay. Data collection and analysis are structured using principles of guided inquiry. Data leading to the calculation of multiple rate constants at varying temper- atures and acid concentrations can

Kelly M. Hutchinson; Stacey Lowery Bretz; Howard D. Mettee; Jeffrey A. Smiley

279

LC Card Order Experiment Conducted at University of Utah Marriott Library  

ERIC Educational Resources Information Center

Between the months of October 1971 and March 1972 the University of Utah Marriott Library conducted an experiment to test the turn-around time of card orders sent to the Library of Congress. This article is a brief report of that experiment. (1 reference) (Author)

Cluff, E. Dale; Anderson, Karen

1973-01-01

280

The Semipermeability of Biological Membranes: An Undergraduate Laboratory Experiment.  

ERIC Educational Resources Information Center

The semipermeability of biological membranes is simply and directly illustrated in an experiment which uses ovolecithin liposomes as convenient models for biological membranes. Background information and procedures used are provided. (JN)

Frimer, Aryeh A.

1985-01-01

281

Metallo Complexes: An Experiment for the Undergraduate Laboratory.  

ERIC Educational Resources Information Center

Describes an experiment in which several metallo complexes with different central atoms are prepared. Background information on these compounds is provided, including requirements for their formation, preparation methods, and comments on their general properties and analysis. (JN)

Kauffman, George B.; And Others

1984-01-01

282

Long-Range (Forster) Electronic Energy Transfer: A Laboratory Experiment.  

ERIC Educational Resources Information Center

An experiment which measures the steady-state fluorescence of pyrene (the donor) in the presence of varying concentrations of acridine orange (the acceptor) in ethyline glycol solutions is described. Background information, equipment needed, and procedures used are included. (JN)

Berkovic, G.

1984-01-01

283

Using Microcomputers in the Physical Chemistry Laboratory: Activation Energy Experiment.  

ERIC Educational Resources Information Center

Describes a computer program, "Activation Energy," which is designed for use in physical chemistry classes and can be modified for kinetic experiments. Provides suggestions for instruction, sample program listings, and information on the availability of the program package. (ML)

Touvelle, Michele; Venugopalan, Mundiyath

1986-01-01

284

Exploring Fundamental Concepts in Aqueous Solution Conductivity: A General Chemistry Laboratory Exercise  

ERIC Educational Resources Information Center

Using a conductivity sensor, a temperature sensor, and a datalogger, fundamental factors that affect conductivity are explored. These factors are (i) concentration, (ii) temperature, (iii) ion charge, and (iv) size and or mass of anion. In addition, the conductivities of a number of other solutions are measured. This lab has been designed to…

Nyasulu, Frazier; Stevanov, Kelly; Barlag, Rebecca

2010-01-01

285

Compressed natural gas and liquefied petroleum gas conversions: The National Renewable Energy Laboratory`s experience  

Microsoft Academic Search

The National Renewable Energy Laboratory (NREL) contracted with conversion companies in six states to convert approximately 900 light-duty Federal fleet vehicles to operate on compressed natural gas (CNG) or liquefied petroleum gas (LPG). The contracts were initiated in order to help the Federal government meet the vehicle acquisition requirements of the Energy Policy Act of 1992 (EPACT) during a period

R. C. Motta; K. J. Kelly; W. W. Warnock

1996-01-01

286

Laboratory Instruction in the Service of Science Teaching and Learning: Reinventing and Reinvigorating the Laboratory Experience  

ERIC Educational Resources Information Center

The Benchmarks for Science Literacy and the National Science Education Standards strongly suggest that students should be engaged in hands-on learning. However, from many corners, the original "mental training" rationale for school labs has been criticized, the "cookbook" nature of laboratory exercises condemned, and the prevalence of using…

McComas, William

2005-01-01

287

Feasibility study to conduct windblown sediment experiments aboard a space station  

NASA Technical Reports Server (NTRS)

A feasibility study was undertaken to determine if a suitable apparatus could be designed to analyze aeolian processes for operation in space and to assess the feasibility of conducting meaningful experiments to address key aspects of aeolian processes. To meet this objective a prototype apparatus was fabricated and some limited experiments were run to determine its suitability for this application. At least three general types of experiments were devised that could be carried out aboard a space station: threshold studies, swirl (dust devil) experiments, and analyses of windblown particle trajectories. How experiments in a zero-g environment could advance knowledge of aeolian processes was studied.

Greeley, R.; Iversen, J. D.

1983-01-01

288

Laboratory-Scale Uranium RF Plasma Confinement Experiments.  

National Technical Information Service (NTIS)

An experimental investigation was conducted using 80 kW and 1.2 MW RF induction heater facilities to aid in developing the technology necessary for designing a self-critical fissioning uranium plasma core reactor. Pure uranium hexafluoride (UF6) was injec...

W. C. Roman

1976-01-01

289

Exploring the universe in the laboratory: photoionized plasma experiments at Z relevant to astrophysics  

NASA Astrophysics Data System (ADS)

Many astrophysical environments such as x-ray binaries, active galactic nuclei, and accretion disks of compact objects have photoionized plasmas. Detailed x-ray spectral observations performed with the Chandra and XMM-Newton orbiting telescopes provide critical information on the state of photoionized plasmas. However, the complexity of the astrophysical environment makes the spectral analysis challenging, and thus laboratory experiments are important for data interpretation and testing of modeling codes. The Z facility at Sandia National Laboratories is a powerful source of x-rays to produce and study in the laboratory photoionized plasmas relevant for astrophysics. We discuss an experimental and theory/modeling effort in which the intense x-ray flux emitted at the collapse of a z-pinch implosion conducted at the Z pulsed-power machine is employed to produce a neon photoionized plasma. The broadband x-ray radiation flux from the z-pinch is used to both create the photoionized plasma and provide a source of backlighting photons to study the atomic kinetics through K-shell line absorption spectroscopy. The plasma is contained in a cm-scale gas cell that can be located at different distances from the z-pinch, thus effectively controlling the x-ray flux producing the plasma. Time-integrated transmission spectra have been observed with a spectrometer equipped with two elliptically-bent KAP crystals from photoionized plasmas covering an order of magnitude range in ionization parameter. The transmission data shows a rich line absorption spectrum that spans over several ionization stages of neon including Be-, Li-, He- and H-like ions. Modeling calculations are used to interpret the transmission spectra recorded in the Z experiments with the goal of extracting the charge- state distribution, electron temperature and the radiation flux driving the plasma, as well as to determine the ionization parameter of the plasma. This work is sponsored in part by the National Nuclear Security Administration under the High Energy Density Laboratory Plasmas grant program through DOE Grant DE-FG52-09NA29551, and the Z Facility Fundamental Science Program of Sandia National Laboratories.

Mancini, Roberto

2014-08-01

290

Savannah River Laboratory's operating experience with glass melters  

SciTech Connect

The Department of Energy, with recommendations from the Du Pont Company, is proposing that a Defense Waste Processing Facility be constructed at the Savannah River Plant to immobilize radioactive The immobilization process is designed around the solidification of waste sludge in borosilicate glass. The Savannah River Laboratory, who is responsible for the solidification process development program, has completed an experimental program with one large-scale glass melter and just started up another melter. Experimental data indicate that process requirements can easily be met with the current design. 7 figures.

Brown, F H; Randall, C T; Cosper, M B; Moseley, J P

1982-01-01

291

Laboratory experiments of relevance to the space station environment  

NASA Technical Reports Server (NTRS)

It has been found that the interaction between orbital vehicles and the ambient environment produces a contaminant cloud which can cause deletrious effects to spacecraft materials and equipment, create increased radiative backgrounds that would interfere with observational instrumentation, and enhance surface charging. A brief overview of the phenomena that produce the contaminant cloud is presented along with a review of physical data required to characterize it. Laboratory techniques which can be utilized to provide the required data are described. In particular, several oxygen beam apparati are discussed.

Caledonia, G. E.

1988-01-01

292

Effect of Bacillus subtilis on Granite Weathering: A Laboratory Experiment  

NASA Astrophysics Data System (ADS)

We performed a comparative experiment to investigate how the ubiquitous soil bacterium Bacillus subtilis weathers granite and which granite-forming minerals weather more rapidly via biological processes. Batch type experiments (granite specimen in a 500 ml solution including NaCl, glucose, yeast extract and bacteria Bacillus subtilis at 27°E C) were carried out for 30 days. Granite surfaces were observed by SEM before and after the experiment. Bacillus subtilis had a strong influence on granite weathering by forming pits. There were 2.4 times as many pits and micropores were 2.3 times wider in granite exposed to Bacillus subtilis when compared with bacteria-free samples. Bacillus subtilis appear to preferentially select an optimum place to adhere to the mineral and dissolve essential elements from the mineral to live. Plagioclase was more vulnerable to bacterial weathering than biotite among the granite composing minerals.

Song, W.; Ogawa, N.; Oguchi, C. T.; Hatta, T.; Matsukura, Y.

2006-12-01

293

Acid/base front propagation in saturated porous media: 2D laboratory experiments and modeling.  

PubMed

We perform laboratory scale reactive transport experiments involving acid-basic reactions between nitric acid and sodium hydroxide. A two-dimensional experimental setup is designed to provide continuous on-line measurements of physico-chemical parameters such as pH, redox potential (Eh) and electrical conductivity (EC) inside the system under saturated flow through conditions. The electrodes provide reliable values of pH and EC, while sharp fronts associated with redox potential dynamics could not be captured. Care should be taken to properly incorporate within a numerical model the mixing processes occurring inside the electrodes. The available observations are modeled through a numerical code based on the advection-dispersion equation. In this framework, EC is considered as a variable behaving as a conservative tracer and pH and Eh require solving the advection dispersion equation only once. The agreement between the computed and measured pH and EC is good even without recurring to parameters calibration on the basis of the experiments. Our findings suggest that the classical advection-dispersion equation can be used to interpret these kinds of experiments if mixing inside the electrodes is adequately considered. PMID:22784659

Loyaux-Lawniczak, Stéphanie; Lehmann, François; Ackerer, Philippe

2012-09-01

294

Laboratory hydraulic fracturing experiments in intact and pre-fractured rock  

USGS Publications Warehouse

Laboratory hydraulic fracturing experiments were conducted to investigate two factors which could influence the use of the hydrofrac technique for in-situ stress determinations; the possible dependence of the breakdown pressure upon the rate of borehole pressurization, and the influence of pre-existing cracks on the orientation of generated fractures. The experiments have shown that while the rate of borehole pressurization has a marked effect on breakdown pressures, the pressure at which hydraulic fractures initiate (and thus tensile strength) is independent of the rate of borehole pressurization when the effect of fluid penetration is negligible. Thus, the experiments indicate that use of breakdown pressures rather than fracture initiation pressures may lead to an erroneous estimate of tectonic stresses. A conceptual model is proposed to explain anomalously high breakdown pressures observed when fracturing with high viscosity fluids. In this model, initial fracture propagation is presumed to be stable due to large differences between the borehole pressure and that within the fracture. In samples which contained pre-existing fractures which were 'leaky' to water, we found it possible to generate hydraulic fractures oriented parallel to the direction of maximum compression if high viscosity drilling mud was used as the fracturing fluid. ?? 1977.

Zoback, M. D.; Rummel, F.; Jung, R.; Raleigh, C. B.

1977-01-01

295

Laptops in Psychology: Conducting Flexible In-Class Research and Writing Laboratories  

ERIC Educational Resources Information Center

This chapter describes an undergraduate psychology research methods course in which laptops facilitated online organization, electronic portfolios, and flexible laboratories to improve student engagement, capability, and understanding. (Contains 3 figures.)

Stephens, Benjamin R.

2005-01-01

296

LABORATORY AND FIELD RESULTS LINKING HIGH CONDUCTIVITIES TO THE MICROBIAL DEGRADATION OF PETROLEUM HYDROCARBONS  

EPA Science Inventory

The results of a field and laboratory investigation of unconsolidated sediments contaminated by petroleum hydrocarbons and undergoing natural biodegradation are presented. Fundamental to geophysical investigations of hydrocarbon impacted sediments is the assessment of how microbi...

297

The Spacecraft Control Laboratory Experiment (SCOLE) - A reprise  

NASA Technical Reports Server (NTRS)

The research experience of SCOLE developed by the NASA Langley Research Center is reviewed. Particular attention is given to the advances made in control and modeling techniques, the experimental facilities that are now available, and the continuing needs to advance and to validate the technologies in controlling flexible structures.

Taylor, L. W., Jr.; Balakrishnan, A. V.

1992-01-01

298

An Approach to Poiseuille's Law in an Undergraduate Laboratory Experiment  

ERIC Educational Resources Information Center

The continuous growth of computer and sensor technology allows many researchers to develop simple modifications and/or refinements to standard educational experiments, making them more attractive and comprehensible to students and thus increasing their educational impact. In the framework of this approach, the present study proposes an alternative…

Sianoudis, I. A.; Drakaki, E.

2008-01-01

299

Experimenting in a Constructivist High School Physics Laboratory  

NSDL National Science Digital Library

Presents a study involving students (n=46) enrolled in an introductory physics course designed to describe and understand students' experimenting and problem-solving strategies in a constructivist learning environment. Concludes that students should be provided with problem-rich learning environments in which they learn to investigate phenomena of their own interest and can develop complex problem-solving skills.

Roth, Wolff-Michael

2006-10-09

300

Cavity Ring down Spectroscopy Experiment for an Advanced Undergraduate Laboratory  

ERIC Educational Resources Information Center

A simple experiment is described that permits advanced undergraduates to learn the principles and applications of the cavity ring down spectroscopy technique. The apparatus is used for measurements of low concentrations of NO[subscript 2] produced in air by an electric discharge. We present the setup, experimental procedure, data analysis and some…

Stacewicz, T.; Wasylczyk, P.; Kowalczyk, P.; Semczuk, M.

2007-01-01

301

Coulometric Analysis Experiment for the Undergraduate Chemistry Laboratory  

ERIC Educational Resources Information Center

An undergraduate experiment on coulometric analysis of four commercial household products is presented. A special type of coulometry cell made of polydimethylsiloxane (PDMS) polymer is utilized. The PDMS cell consists of multiple analyte compartments and an internal network of salt bridges. Experimental procedure for the analysis of the acid in a…

Dabke, Rajeev B.; Gebeyehu, Zewdu; Thor, Ryan

2011-01-01

302

Car-Crash Experiment for the Undergraduate Laboratory  

ERIC Educational Resources Information Center

Describes an interesting, inexpensive, and highly motivating experiment to study uniform and accelerated motion by measuring the position of a car as it crashes into a rigid wall. Data are obtained from a sequence of pictures made by a high speed camera. (Author/SLH)

Ball, Penny L.; And Others

1974-01-01

303

Overland Erosion Due To Freeze-Thaw Cycling: Laboratory Experiments.  

National Technical Information Service (NTIS)

Ice that forms in soil voids during the freezing process pushes soil grains apart reducing particle cohesion and soil strength and making soil more erodible. This report summarizes 18 experiments to measure erosion rates in a soil that was frozen and thaw...

L. W. Gatto M. G. Ferrick

2003-01-01

304

Neutrino-oscillation experiments at Brookhaven National Laboratory  

SciTech Connect

Two groups have submitted major proposals for neutrino oscillation searches at BNL. Both are two detector experiments with a close detector at approx. = 100m and a far detector at approx. = 900m. While the details of the experiments are quite different, both groups expect to obtain nu/sub ..mu../ disappearance limits of delta m/sup 2/sin2 theta approx. = 0.1 - 0.2 for small mass difference and sin/sup 2/2 theta at the few percent level for the most sensitive delta m/sup 2/(approx. = 25eV/sup 2/). Since both detectors are designed to identify electrons as well as muons they expect to obtain significant limits on nu/sub e/ appearance (nu/sub ..mu../ ..-->.. nu/sub e/). Each has received approval for a single detector (Phase I) experiment with the two detector phase (Phase II) still pending. The present status of the single detector experiments is detailed. (WHK)

Ahrens, L.A.; Aronson, S.A.; Connolly, P.L.; Gibbard, B.G.; Maeda, Y.; Murtagh, M.J.; Murtagh, S.J.; Terada, S.; Callas, J.; Cutts, D.

1983-01-01

305

A Process Dynamics and Control Experiment for the Undergraduate Laboratory  

ERIC Educational Resources Information Center

This paper describes a process control experiment. The apparatus includes a three-vessel glass flow system with a variable flow configuration, means for feeding dye solution controlled by a stepper-motor driven valve, and a flow spectrophotometer. Students use impulse response data and nonlinear regression to estimate three parameters of a model…

Spencer, Jordan L.

2009-01-01

306

Holographic study of a vibrating bell: An undergraduate laboratory experiment  

Microsoft Academic Search

An experiment combining holography and musical acoustics is described. Structures of vibration modes of a bell are visualized by time-average holography under either acoustical or mechanical excitation. The vibration amplitude as measured by an accelerometer shows very good quantitative agreement with that determined from our holograms by fringe counting. An effect of degenerate level separation is shown in the mechanical

Kristen Menou; Benjamin Audit; Xavier Boutillon; Holger Vach

1998-01-01

307

User Experience in Digital Games: Differences between Laboratory and Home  

ERIC Educational Resources Information Center

Playing entertainment computer, video, and portable games, namely, digital games, is receiving more and more attention in academic research. Games are studied in different situations with numerous methods, but little is known about if and how the playing situation affects the user experience (UX) in games. In addition, it is hard to understand and…

Takatalo, Jari; Hakkinen, Jukka; Kaistinen, Jyrki; Nyman, Gote

2011-01-01

308

Extraction and Assay of Ornithine Decarboxylase: A Laboratory Experiment that Introduces Principles of Radiochemical Enzymatic Assay  

NASA Astrophysics Data System (ADS)

A laboratory experiment involving preparation of an Escherichia coli extract in which ornithine decarboxylase (ODC) is quantitated by radiochemical assay has been developed. The assay is based on the ODC-catalyzed decarboxylation of [1-14C]ornithine to yield 14CO2. Procedures for growth of the bacteria, preparation of the extract and assay of the enzyme are described. Points to be considered before adopting the experiment and potential problems are discussed. The experiment gives students experience in laboratory procedures, safety precautions and calculations associated with the use of radioactive compounds. It introduces principles common in radiochemical work and illustrates sensitivity and selectivity of a well-designed enzyme assay. It is often the first time students encounter a situation in which enzyme stereospecificity must be taken into account in a laboratory procedure. The experiment is suitable for use in biochemistry, radiochemistry or chemically-oriented cell biology laboratory classes.

Voige, William H.

1997-08-01

309

Laboratory Experiments on the Control of Cyclops Transmitting Guinea Worm  

PubMed Central

Infection with the guinea worm (Dracunculus medinensis) affects millions of people living in rural areas in certain parts of the world. Usually, the standard of living is low and elaborate control measures would not be feasible. In this study, various insecticidal and molluscicidal compounds were tested in the laboratory for their toxicity to the intermediate hosts, namely, various species of cyclops, which often live in sources of potable water, such as step-wells, cisterns and ponds. Cheapness, low toxicity to mammals and ease of application, in conjunction with effectiveness against cyclops, are primary requisites for any compound accepted for widespread use. Abate, an insecticide, has been shown to be particularly promising in these respects. The timing and mode of application of compounds toxic to cyclops in various endemic regions are discussed.

Muller, Ralph

1970-01-01

310

Role of Organic Acids in Bioformation of Kaolinite: Results of Laboratory Experiments  

NASA Astrophysics Data System (ADS)

Clay minerals and other solid silica phases have a broad distribution in the geological record and greatly affect fundamental physicochemical properties of sedimentary rocks, including porosity. An increasing number of studies suggests that microbial activity and microbially produced organic acids might play an important role in authigenic clay mineral formation, at low temperatures and under neutral pH conditions. In particular, early laboratory experiments (Linares and Huertas, 1971) reported the precipitation of kaolinite in solutions of SiO2 and Al2O3 with different molar ratios SiO2/Al2O3, together with fulvic acid (a non-characterized mixture of many different acids containing carboxyl and phenolate groups) that was extracted from peat soil. Despite many attempts, these experiments could not be reproduced until recently. Fiore et al. (2011) hypothesized that the non-sterile fulvic acid might have contained microbes that participated in the formation of kaolinite. Using solutions saturated with Si and Al and containing oxalate and/or mixed microbial culture extracted from peat-moss soil, they performed incubation experiments, which produced kaolinite exclusively in solutions containing oxalate and microbes. We proposed to test the role of specific organic acids for kaolinite formation, conducting laboratory experiments at 25?C, with solutions of sodium silicate, aluminum chloride and various organic compounds (i.e. EDTA, citric acid, succinic acid and oxalic acid). Specific organic acids may stabilize aluminum in octahedral coordination positions, which is crucial for the initial nucleation step. In our experiments, a poorly crystalline mineral that is possibly a kaolinite precursor formed exclusively in the presence of succinic acid. In experiments with other organic compounds, no incorporation of Al was observed, and amorphous silica was the only precipitated phase. In natural environments, succinic acid is produced by a large variety of microbes as an intermediate product of the tricarboxylic acid cycle. Our results demonstrate, for the first time, that the formation of a specific clay mineral (proto-kaolinite) occurs in the presence of a specific organic compound (succinic acid). This implies that microbial species capable of excreting succinate among their EPS may promote authigenic kaolinite formation at low temperature and neutral pH. This biological degradation process might play a crucial role for the formation of authigenic kaolinite, which is a widespread clay mineral in sedimentary environments. Fiore, S., Dumontet, S., Huertas, F.J., and Pasquale, V., 2011. Bacteria-induced crystallization of kaolinite. Applied Clay Science, 53:566-571. Linares, J., and Huertas, F., 1971. Kaolinite: Synthesis at room temperature. Science 171: 896-897.

Bontognali, T. R. R.; Vasconcelos, C.; McKenzie, J. A.

2012-04-01

311

Ion acoustic wave experiments in a high school plasma physics laboratory  

Microsoft Academic Search

We describe a successful alliance between a university and several high schools. The alliance is centered on a laboratory experiment constructed by students and faculty. The experiment involves sophisticated concepts and equipment not readily available in high schools. Much of the experiment is directly related to the science and mathematics learned in high school, with opportunities to extend their understanding

Walter Gekelman; J. Wise; P. Pribyl; R. Baker; W. Layton; J. Skrzypek; P. Niknejadi; R. Ransom; D. Lee; R. Zarinshesnas; T. Kim; R. Buck; E. Warfel; T. Tasoff; J. Carmona; S. Skolnik; L. Kim; D. Furlong; N. Gibson

2007-01-01

312

Microscale Organic Laboratory II: The Benefits Derived from Conversion to the Program and Representative Experiments.  

ERIC Educational Resources Information Center

Smaller amounts of materials are used in organic chemistry experiments as a means of improving air quality in the laboratory. Outlines benefits from this approach and describes two representative experiments in detail. These experiments are the Cannizzaro reaction and preparation of an aromatic nitrile. (JN)

Mayo, Dana W.; And Others

1985-01-01

313

Augmenting traditional undergraduate advanced laboratory experiments by automation using IEEE488 and RS232 interfaces  

Microsoft Academic Search

Meaningful and effective use of the computer in undergraduate physics teaching has been unexpectedly and somewhat paradoxically slow. Some upper division laboratory experiments are described in which the computer is used in a way that preserves the traditional value and importance of classic experiments and minimizes the intrusion of the computer. Experiments and the equipment are chosen to minimize programming

S. Nornes; Y. Z. Tu

1989-01-01

314

Thermodynamics of DNA Duplex Formation: A Biophysical Chemistry Laboratory Experiment  

Microsoft Academic Search

The goal of this biophysical experiment is to measure thermodynamic properties of a short DNA duplex by melting the ordered native structure (duplex) into the disordered, denatured state (single strands) while monitoring the transition using ultraviolet spectrophotometry. The DNA samples we used were two complementary synthetic DNA oligomers, dCA7G and dCT7G. The absorbance of four separate DNA samples with different

Kathleen P. Howard

2000-01-01

315

Spectral induced polarization monitoring of CO2 injection in saturated sands: a laboratory experiment  

NASA Astrophysics Data System (ADS)

During the last decade, the interest of induced polarization methods for environmental studies has undoubtly grown. Here, we present a set of laboratory experiments aimed at assessing the ability of spectral induced polarisation (SIP) method to detect and monitor CO2 transfers in the subsurface. The objectives were the quantification of the influence of various parameters on the SIP response, such as the water conductivity, the chemical reactivity of the solid and of the gas phases, and the injection rate. SIP measurements in the frequency range 50 mHz - 20 kHz were thus performed during gas (N2 or CO2) injections in a metric-scaled, cylindrical tank filled with unconsolidated granular material (quartz or carbonate sands) and fully saturated with water. The system was most reactive to gas injection in the high frequency range (>1 kHz). In quartz sand, the presence of gas in the medium tends to decrease the measured values of the phase angle. This effect becomes more important when increasing the injection rate, and thus the amount of gas trapped in the medium. The magnitude of this effect decreases when the water conductivity increases. Dissolution processes (CO2 in water and also solid matrix in the case of carbonate sand) were evidenced from chemical measurements (pH, conductivity and anionic concentrations). The increased ionic strength resulted in a decrease of the bulk resistivity and in an increase of the phase values at high frequency. An interesting parameter is the ratio of the increase in phase to the decrease in resistivity. When dissolution processes are involved, this ratio increases strongly with the initial conductivity of the saturating fluid. Hence, in some cases the measured phase values still bring measurable information on the system evolution even if resistivity variations are very small.

Kremer, T.; Schmutz, M.; Agrinier, P.; Maineult, A. J.

2013-12-01

316

Benchmarking in a differentially heated rotating annulus experiment: Multiple equilibria in the light of laboratory experiments and simulations  

NASA Astrophysics Data System (ADS)

In the framework of the German Science Foundation's (DFG) priority program 'MetStröm' various laboratory experiments have been carried out in a differentially heated rotating annulus configuration in order to test, validate and tune numerical methods to be used for modeling large-scale atmospheric processes. This classic experimental set-up is well known since the late 1940s and is a widely studied minimal model of the general mid-latitude atmospheric circulation. The two most relevant factors of cyclogenesis, namely rotation and meridional temperature gradient are quite well captured in this simple arrangement. The tabletop-size rotating tank is divided into three sections by coaxial cylindrical sidewalls. The innermost section is cooled whereas the outermost annular cavity is heated, therefore the working fluid (de-ionized water) in the middle annular section experiences differential heat flow, which imposes thermal (density) stratification on the fluid. At high enough rotation rates the isothermal surfaces tilt, leading to baroclinic instability. The extra potential energy stored in this unstable configuration is then converted into kinetic energy, exciting drifting wave patterns of temperature and momentum anomalies. The signatures of these baroclinic waves at the free water surface have been analysed via infrared thermography in a wide range of rotation rates (keeping the radial temperature difference constant) and under different initial conditions (namely, initial spin-up and "spin-down"). Paralelly to the laboratory simulations of BTU Cottbus-Senftenberg, five other groups from the MetStröm collaboration have conducted simulations in the same parameter regime using different numerical approaches and solvers, and applying different initial conditions and perturbations for stability analysis. The obtained baroclinic wave patterns have been evaluated via determining and comparing their Empirical Orthogonal Functions (EOFs), drift rates and dominant wave modes. Thus certain "benchmarks" have been created that can later be used as test cases for atmospheric numerical model validation. Both in the experiments and in the numerics multiple equilibrium states have been observed in the form of hysteretic behavior depending on the initial conditions. The precise quantification of these state and wave mode transitions may shed light to some aspects of the basic underlying dynamics of the baroclinic annulus configuration, still to be understood.

Vincze, Miklos; Harlander, Uwe; Borchert, Sebastian; Achatz, Ulrich; Baumann, Martin; Egbers, Christoph; Fröhlich, Jochen; Hertel, Claudia; Heuveline, Vincent; Hickel, Stefan; von Larcher, Thomas; Remmler, Sebastian

2014-05-01

317

MREIT conductivity imaging based on the local harmonic Bz algorithm: Animal experiments  

NASA Astrophysics Data System (ADS)

From numerous numerical and phantom experiments, MREIT conductivity imaging based on harmonic Bz algorithm shows that it could be yet another useful medical imaging modality. However, in animal experiments, the conventional harmonic Bz algorithm gives poor results near boundaries of problematic regions such as bones, lungs, and gas-filled stomach, and the subject boundary where electrodes are not attached. Since the amount of injected current is low enough for the safety for in vivo animal, the measured Bz data is defected by severe noise. In order to handle such problems, we use the recently developed local harmonic Bz algorithm to obtain conductivity images in our ROI(region of interest) without concerning the defected regions. Furthermore we adopt a denoising algorithm that preserves the ramp structure of Bz data, which informs of the location and size of anomaly. Incorporating these efficient techniques, we provide the conductivity imaging of post-mortem and in vivo animal experiments with high spatial resolution.

Jeon, Kiwan; Lee, Chang-Ock; Woo, Eung Je; Kim, Hyung Joong; Seo, Jin Keun

2010-04-01

318

Definition of experiments and instruments for a communication/navigation research laboratory. Volume 1: Executive summary  

NASA Technical Reports Server (NTRS)

This study was undertaken to develop conceptual designs for a manned, space shuttle sortie mission laboratory capable of supporting a wide variety of experiments in conjunction with communications and navigation research. This space/laboratory would be one in which man may effectively increase experiment efficiency by certain observations, modifications, setup, calibration, and limited maintenance steps. In addition, man may monitor experiment progress and perform preliminary data evaluation to verify proper equipment functioning and may terminate or redirect experiments to obtain the most desirable end results. The flexibility and unique capabilities of man as an experimenter in such a laboratory will add greatly to the simplification of space experiments and this provides the basis for commonality in many of the supportive subsystems, thus reaping the benefits of reusability and reduced experiment costs. For Vol. 4, see N73-19268.

1972-01-01

319

Subpicosecond compression experiments at Los Alamos National Laboratory  

SciTech Connect

The authors report on recent experiments using a magnetic chicane compressor at 8 MeV. Electron bunches at both low (0.1 nC) and high (1 nC) charges were compressed from 20 ps to less than 1 ps (FWHM). A transverse deflecting rf cavity was used to measure the bunch length at low charge; the bunch length at high charge was inferred from an induced energy spread of the beam. The longitudinal centrifugal-space charge force is calculated using a point-to-point numerical simulation and is shown not to influence the energy-spread measurement.

Carlsten, B.E.; Russell, S.J.; Kinross-Wright, J.M. [and others

1995-09-01

320

Subpicosecond Compression Experiments at Los Alamos National Laboratory  

NASA Astrophysics Data System (ADS)

We report on recent experiments using a magnetic chicane compressor at 8 MeV. Electron bunches at both low (0.1 nC) and high (1 nC) charges were compressed from 10-15 ps to less than 1 ps (FWHM). A transverse deflecting rf cavity was used to measure the bunch length at low charge; the bunch length at high charge was inferred from the induced energy spread of the beam. The longitudinal centrifugal space-charge force [Phys. Rev. E 51, 1453 (1995)] is calculated using a point-to-point numerical simulation and is shown not to influence the energy-spread measurement.

Carlsten, Bruce E.; Feldman, Donald W.; Kinross-Wright, John M.; Milder, Martin L.; Russell, Steven J.; Plato, John G.; Sherwood, Boyd A.; Weber, Michael E.; Cooper, Ronald G.; Sturges, Ronald E.

1996-04-01

321

Laboratory and clinical experience with neodymium:YAG laser prostatectomy  

NASA Astrophysics Data System (ADS)

Since 1991, we have undertaken extensive laboratory and clinical studies of the Neodymium:YAG (Nd:YAG) laser for surgical treatment of bladder outlet obstruction due to prostatic enlargement or benign prostatic hyperplasia (BPH). Side-firing optical fibers which emit a divergent, relatively low energy density Nd:YAG laser beam produce coagulation necrosis of obstructing periurethral prostate tissue, followed by gradual dissolution and slough in the urinary stream. Laser-tissue interactions and Nd:YAG laser dosimetry for prostatectomy have been studied in canine and human prostate model systems, enhancing clinical application. Ongoing studies examine comparative Nd:YAG laser dosimetry for various beam configurations produced by available side-firing optical fibers and continue to refine operative technique. We have documented clinical outcomes of Nd:YAG laser prostatectomy in 230 consecutive patients treated with the UrolaseTM side-firing optical fiber. Nd:YAG laser coagulation the prostate produces a remarkably low acute morbidity profile, with no significant bleeding or fluid absorption. No postoperative incontinence has been produced. Serial assessments of voiding outcomes over more than 3 years of followup show objective and symptomatic improvement following Nd:YAG laser prostatectomy which is comparable to older but more morbid electrosurgical approaches. Nd:YAG laser prostatectomy is a safe, efficacious, durable and cost-effective treatment for BPH.

Kabalin, John N.

1996-05-01

322

Integrated laboratory scale demonstration experiment of S-I cycle  

SciTech Connect

The Sulfur Iodine thermochemical cycle for the production of hydrogen is one of the promising approaches for use with next generation high temperature advanced nuclear reactors. Within the framework of an international collaboration (I-NERI project) between the American DOE and the French CEA, the development of a laboratory scale hydrogen production loop using the sulfur iodine cycle will be performed under prototypic conditions to demonstrate the key chemical processes, to check the materials and to provide the technical basis for evaluating the S-I cycle for nuclear hydrogen production (process efficiency and preliminary costs). The S-I cycle has been split into three sections. Each must complete stand alone tests prior to closed loop operation. CEA is responsible for the development, construction and operation of the Bunsen section where hydro-iodic acid and sulfuric acid are generated. After a general description of the loop and its objectives, a focus is made on the section provided by CEA, its design and the first tests performed in stand-alone mode. Reflexions on a preliminary scale up of major components for an industrial unit are also discussed. (authors)

Leybros, Jean; Duhamet, Jean; Ode, Denis; Pons, Nicolas; Dehaudt, Philippe; Boidron, Michel [Commissariat a l'Energie Atomique DEN/VRH/DTEC BP17171 - Marcoule - 30207 BAGNOLS SUR CEZE Cedex (France); Helie, Max [Commissariat a l'Energie Atomique, DEN/DANS/DPC - Centre de Saclay - 91191 GIF-SUR YVETTE Cedex (France)

2007-07-01

323

Screening for group B streptococcus: a private laboratory experience.  

PubMed

We examined group B streptococcus (GBS) isolates colonizing women at the 35-37 weeks of pregnancy. A total of 257 group B streptococcus (GBS) isolates for serotyped using direct agglutination with a set of commercially available antisera (Ia, Ib, II, III, IV, and V) and tested for susceptibility to antimicrobials (penicillin, macrolides, lincosamides, fluoroquinolones and tetracyclines). Fourteen isolates could not be serotyped with the antisera set used in the study. Serotype III was the predominant serotype (33%), followed by serotypes V (23%), and Ia (20%). Whereas all isolates were susceptible to penicillin, the rates of susceptibility to the other antimicrobials tested were the following: 91% for ofloxacin, 80% for clindamycin, 77% for erythromycin, and 4% for tetracycline. More than half (67%) of the macrolide resistant isolates belonged to serotypes V and III. A systematic surveillance of the autochthonous GBS serotypes, performed at the level of laboratories processing a high number of human specimens, is mandatory for strengthening the national epidemiological GBS surveillance. While penicillin remains the drug of choice for intrapartum prophylaxis, the resistance of autochthonous GBS isolates to other antibiotics should be actively monitored. PMID:22106511

Cristea, Violeta-Corina; Du??, Maria; Neac?u, Gabriela

2011-01-01

324

Insights into oil cracking based on laboratory experiments  

USGS Publications Warehouse

The objectives of this pyrolysis investigation were to determine changes in (1) oil composition, (2) gas composition and (3) gas carbon isotope ratios and to compare these results with hydrocarbons in reservoirs. Laboratory cracking of a saturate-rich Devonian oil by confined, dry pyrolysis was performed at T = 350-450??C, P = 650 bars and times ranging from 24 h to 33 days. Increasing thermal stress results in the C15+ hydrocarbon fraction cracking to form C6-14 and C1-5 hydrocarbons and pyrobitumen. The C6-14 fraction continues to crack to C 1-5 gases plus pyrobitumen at higher temperatures and prolonged heating time and the ?? 13Cethane-?? 13Cpropane difference becomes greater as oil cracking progresses. There is considerable overlap in product generation and product cracking. Oil cracking products accumulate either because the rate of generation of any product is greater than the rate of removal by cracking of that product or because the product is a stable end member under the experimental conditions. Oil cracking products decrease when the amount of product generated from a reactant is less than the amount of product cracked. If pyrolysis gas compositions are representative of gases generated from oil cracking in nature, then understanding the processes that alter natural gas composition is critical. ?? 2003 Elsevier Ltd. All rights reserved.

Hill, R. J.; Tang, Y.; Kaplan, I. R.

2003-01-01

325

Laboratory Experiments, Numerical Simulations, and Astronomical Observations of Deflected Supersonic Jets: Application to HH 110  

Microsoft Academic Search

Collimated supersonic flows in laboratory experiments behave in a similar\\u000amanner to astrophysical jets provided that radiation, viscosity, and thermal\\u000aconductivity are unimportant in the laboratory jets, and that the experimental\\u000aand astrophysical jets share similar dimensionless parameters such as the Mach\\u000anumber and the ratio of the density between the jet and the ambient medium.\\u000aLaboratory jets can be

P. Hartigan; J. M. Foster; B. H. Wilde; R. F. Coker; P. A. Rosen; J. F. Hansen; B. E. Blue; R. J. R. Williams; R. Carver; A. Frank

2009-01-01

326

Practical advice for conducting ethical online experiments and questionnaires for United States psychologists  

Microsoft Academic Search

It is increasingly easy and, therefore, increasingly common to conduct experiments and questionnaire studies in online environments.\\u000a However, the online environment is not a data collection medium that is familiar to many researchers or to many research methods\\u000a instructors. Because of this, researchers have received little information about how to address ethical issues when conducting\\u000a online research. Researchers need practical

Kimberly A. Barchard; John Williams

2008-01-01

327

Slip localization and fault weakening as a consequence of fault gouge strengthening — Insights from laboratory experiments  

NASA Astrophysics Data System (ADS)

A laboratory study of simulated quartz gouges was conducted to investigate how solution transfer processes influence the mechanical behaviour of fault wear products at high temperature, hydrothermal conditions. Experiments were performed under nominally dry conditions, as well as in the presence of an aqueous pore fluid, at elevated temperatures (500 to 927 °C), and at effective confining pressure conditions ( ?2' = ?3' = 100 MPa) to simulate, on a laboratory timescale, processes that may be important in fluid-active fault zones at depth in the continental crust. The mechanical data and microstructural analysis indicate that the kinetics of solution transfer processes can exert a fundamental control on the mechanical behaviour of fault wear products. It is found that, at nominally dry conditions, gouges deform by cataclastic creep and distributed shear, with strength and microstructures being relatively unaffected by temperature. At moderately chemically reactive, hydrothermal conditions (500-600 °C, coarse grain size, or fast deformation rate), the presence of a reactive pore fluid slightly reduces the shear strength with respect to dry conditions. However, at highly chemically reactive, hydrothermal conditions (600-927 °C, small grain size, and slow deformation rate), rapid porosity reduction is accommodated by dissolution-precipitation processes. Deformation under such conditions results in a fast increase of grain contact area and the development of cohesive bonds between adjacent particles, which in turn inhibits cataclastic granular flow. With increasing displacement and compaction of the quartz gouge, there is a sudden transition from distributed cataclastic flow, to slip localization at the interface between the gouge and one of the forcing blocks. This deformation mode switch is associated with dramatic weakening (up to 50% drop in shear resistance, and changes in the apparent coefficient of friction from > 0.7 to ? 0.4). Stress drop occurs over many minutes in the laboratory. It is speculated that solution-assisted gouge compaction, and consequent slip localization with associated slow, yet dramatic stress drop, could provide a mechanism for the occurrence of slow earthquakes.

Giger, Silvio B.; Cox, Stephen F.; Tenthorey, Eric

2008-11-01

328

Laboratory experiments of heat and moisture fluxes through supraglacial debris  

NASA Astrophysics Data System (ADS)

Inspired by earlier work (Reznichenko et al., 2010), we have carried out experiments within a climate chamber to explore the best ways to measure the heat and moisture fluxes through supraglacial debris. Sample ice blocks were prepared with debris cover of varying lithology, grain size and thickness and were instrumented with a combination of Gemini TinyTag temperature/relative humidity sensors and Decagon soil moisture sensors in order to monitor the heat and moisture fluxes through the overlying debris material when the experiment is exposed to specified solar lamp radiation and laminar airflow within the temperature-controlled climate chamber. Experimental results can be used to determine the optimal set up for numerical models of heat and moisture flux through supraglacial debris and also indicate the performance limitations of such sensors that can be expected in field installations. Reznichenko, N., Davies, T., Shulmeister, J. and McSaveney, M. (2010) Effects of debris on ice-surface melting rates: an experimental study. Journal of Glaciology, Volume 56, Number 197, 384-394.

Nicholson, Lindsey; Mayer, Christoph; Wirbel, Anna

2014-05-01

329

Imidazole as a pH Probe: An NMR Experiment for the General Chemistry Laboratory  

ERIC Educational Resources Information Center

The analysis describes an NMR experiment for the general chemistry laboratory, which employs an unknown imidazole solution to measure the pH values. The described mechanism can also be used for measuring the acidity within the isolated cells.

Hagan, William J., Jr.; Edie, Dennis L.; Cooley, Linda B.

2007-01-01

330

An Experiment Using Sucrose Density Gradients in the Undergraduate Biochemistry Laboratory.  

ERIC Educational Resources Information Center

Describes an experiment to be performed in an undergraduate biochemistry laboratory that is based on a gradient centrifugation system employing a simple bench top centrifuge, a freezer, and frozen surcose gradient solution to separate macromolecules and subcellular components. (CW)

Turchi, Sandra L.; Weiss, Monica

1988-01-01

331

Screening for Saponins Using the Blood Hemolysis Test. An Undergraduate Laboratory Experiment.  

ERIC Educational Resources Information Center

Describes an experiment for undergraduate chemistry laboratories involving a chemical found in plants and some sea animals. Discusses collection and identification of material, a hemolysis test, preparation of blood-coated agar plates, and application of samples. (CW)

Sotheeswaran, Subramaniam

1988-01-01

332

The Quartz-Crystal Microbalance in an Undergraduate Laboratory Experiment: I. Fundamentals and Instrumentation  

ERIC Educational Resources Information Center

The fundamentals, as well as the instrumentation of the quartz-crystal microbalance (QCM) technique that is used in an undergraduate laboratory experiment are being described. The QCM response can be easily used to change the properties of any system.

Tsionsky, Vladimir

2007-01-01

333

Determination of Rate Constants for Ouabain Inhibition of Adenosine Triphosphatase: An Undergraduate Biological Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

Describes an undergraduate biological chemistry laboratory experiment which provides students with an example of pseudo-first-order kinetics with the cardiac glycoside inhibition of mammalism sodium and potassium transport. (SL)

Sall, Eri; And Others

1978-01-01

334

The Synthesis and Proton NMR Spectrum of Methyl 7-Cycloheptatrienylacetate: An Advanced Undergraduate Laboratory Experiment.  

ERIC Educational Resources Information Center

Describes an advanced undergraduate laboratory experiment designed to give the senior chemistry student an opportunity to apply several synthetic and purification techniques as well as possibilities for the application of NMR spectroscopy. (CS)

Jurch, G. R., Jr.; And Others

1980-01-01

335

Cross-Disciplinary Thermoregulation and Sweat Analysis Laboratory Experiences for Undergraduate Chemistry and Exercise Science Students  

NSDL National Science Digital Library

This article describes a qualitative evaluation of Cross-Disciplinary health sciences undergraduate laboratory experiences in which concepts and students from two distinct disciplines (chemistry and exercise physiology) combined to study exercise thermoregulation and sweat analysis.

2011-06-01

336

The Synthesis of a Cockroach Pheromone: An Experiment for the Second-Year Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

This experiment describes the synthesis of gentisyl quinone isovalerate, or blattellaquinone, a sex pheromone of the German cockroach that was isolated and identified in 2005. The synthesis is appropriate for the second semester of a second-year organic chemistry laboratory course. It can be completed in two, three-hour laboratory periods and uses…

Feist, Patty L.

2008-01-01

337

Solvent-Free Wittig Reaction: A Green Organic Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

Some Wittig reactions can be carried out by grinding the reactants in a mortar with a pestle for about 20 minutes, as per investigation. A laboratory experiment involving a solvent-free Wittig reaction that can be completed in a three-hour sophomore organic chemistry laboratory class period, are developed.

Leung, Sam H.; Angel, Stephen A.

2004-01-01

338

Providing a Chemistry Laboratory Experience for a Cerebral-Palsied Student.  

ERIC Educational Resources Information Center

Recounts the experiences of a student with cerebral palsy in a college-level, first-semester chemistry laboratory course. Explains how a laboratory assistant worked with the handicapped student in assembling apparatus and manipulating some of the smaller equipment. Discusses the outstanding work performed by the student. (TW)

Davis, George R.; McGowen, Audrey

1986-01-01

339

Investigating Attachment Behaviors of Cryptosporidium Parvum Oocysts Using Collision Efficiency in Laboratory Column Experiments  

NASA Astrophysics Data System (ADS)

Cryptosporidium is one of the most common enteric parasites of humans and domestic animals, and a number of outbreaks of Cryprosporidiosis, a diarrheal disease caused by Cryptosporidium have been reported worldwide. Natural porous media has been demonstrated to be an effective filter for removing Cryptosporidium parvum from contaminated water and the amount of Cryptosporidium filtered is known to be highly dependent on physical and chemical conditions of the porous media and the water. Cryptosporidium deposition in saturated porous media involves two main steps: approach and attachment. In contrast to the approach mechanisms, attachment processes have not been systematically described to predict a priori because theories that represent attachment behavior (colloid stability) such as DLVO are insufficient to explain experimental data. For this reason, attachment efficiency is calculated based on empirical data, typically experimental breakthrough curves in laboratory columns or field experiments. In this study, collision (attachment) efficiencies (?) of C. parvum oocyst were calculated to test the effect of chemical property changes on the association of oocysts with sand grains. The breakthrough curve data obtained from twelve column experiments and three models were employed to calculate single collector efficiency (?) and ?. The first ten experiments were conducted by changing ionic strength and pH, and mixing with natural sediments under the same physical properties (same ?). Our experiment results show that iron coating or clay/suspended solids mixture drastically enhanced oocyst deposition. The experiments also showed that increase in ionic strength and decrease in pH enhanced the attachment efficiency. However, the experiment with 100mM NaCl resulted in low attachment efficiency and the experiment with pH 8.5 showed similar attachment efficiency to the one at pH 7. Based on the results from two additional experiments with different flow velocities, it appears that attachment efficiency changes when the flow velocity changes, which contradicts CFT. The results prove that predicting attachment efficiency of C. parvum oocyst using ionic strength or pH is inappropriate when non-DLVO interactions are involved. A review of our results and comparison to existing data shows that it is challenging to accurately predict the attachment efficiency using single peak value of breakthrough curve data from geochemical information of porous media.

Park, Y.; Hou, L.; Atwill, R.; Packman, A. I.; Harter, T.

2009-12-01

340

Subpicosecond Compression Experiments at Los Alamos National Laboratory  

SciTech Connect

We report on recent experiments using a magnetic chicane compressor at 8 MeV. Electron bunches at both low (0.1 nC) and high (1 nC) charges were compressed from 10{endash}15 ps to less than 1 ps (FWHM). A transverse deflecting rf cavity was used to measure the bunch length at low charge; the bunch length at high charge was inferred from the induced energy spread of the beam. The longitudinal centrifugal space-charge force [{ital Phys}. {ital Rev}. {ital E} {bold 51}, 1453 (1995)] is calculated using a point-to-point numerical simulation and is shown not to influence the energy-spread measurement. {copyright} {ital 1996 American Institute of Physics.}

Carlsten, B.E.; Feldman, D.W.; Kinross-Wright, J.M.; Milder, M.L.; Russell, S.J.; Plato, J.G.; Sherwood, B.A.; Weber, M.E.; Cooper, R.G.; Sturges, R.E. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States)

1996-04-01

341

Laboratory-scale uranium RF plasma confinement experiments  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted using 80 kW and 1.2 MW RF induction heater facilities to aid in developing the technology necessary for designing a self-critical fissioning uranium plasma core reactor. Pure uranium hexafluoride (UF6) was injected into argon-confined, steady-state, RF-heated plasmas in different uranium plasma confinement tests to investigate the characteristics of plamas core nuclear reactors. The objectives were: (1) to confine as high a density of uranium vapor as possible within the plasma while simultaneously minimizing the uranium compound wall deposition; (2) to develop and test materials and handling techniques suitable for use with high-temperature, high-pressure gaseous UF6; and (3) to develop complementary diagnostic instrumentation and measurement techniques to characterize the uranium plasma and residue deposited on the test chamber components. In all tests, the plasma was a fluid-mechanically-confined vortex-type contained within a fused-silica cylindrical test chamber. The test chamber peripheral wall was 5.7 cm ID by 10 cm long.

Roman, W. C.

1976-01-01

342

Birmingham Urban Climate Laboratory (BUCL): Experiences, Challenges and Applications of an Urban Temperature Network  

NASA Astrophysics Data System (ADS)

The Birmingham Urban Climate Laboratory (BUCL) has recently been established by the University of Birmingham. BUCL is an in-situ, real-time urban network that will incorporate 3 nested networks - a wide-array of 25 weather stations, a dense array of 131 low-cost air temperature sensors and a fine-array of temperature sensor across the city-centre (50/km^2) - with the primary aim of monitoring air temperatures across a morphologically-heterogeneous urban conurbation for a variety of applications. During its installation there have been a number of challenges to overcome, including siting equipment in suitable urban locations, ensuring that the measurements were 'representative' of the local-scale climate, managing a large, near real-time data set and implementing QA/QC procedures. From these experiences, the establishment of a standardised urban meteorological network metadata protocol has been proposed in order to improve data quality, to ensure the end-user has access to all the supplementary information they would require for conducting valid analyses and to encourage the adequate recording and documentation of any changes to in-situ urban networks over time. This paper will provide an introduction to the BUCL in-situ network, give an overview of the challenges and experiences gained from its implementation, and finally discuss the proposed applications of the network, including its use in remote sensing observations of urban temperatures, as well as health and infrastructure applications.

Muller, Catherine; Chapman, Lee; Young, Duick; Grimmond, Sue; Cai, Xiaoming

2013-04-01

343

A laboratory experiment assessing the effect of sea ice on wave dumping  

NASA Astrophysics Data System (ADS)

Wave-ice interaction is a critical factor in the dynamics of the marginal ice zone (MIZ), the region between open ocean and an expanse of ice floes of varying size and shape. This interaction works both ways: while waves cause the fractures of ice floes, the presence of ice floes affects waves through scattering and various dissipative processes. In order to assess the latter, a laboratory experiment has been carried out in the coastal directional basin at Plymouth University. Sea ice has been simulated with two deformable plates: 1mX1m plastic sheet with variable thickness of polypropylene, which holds the same density (~0.9 g/cm3) of ice, and PVC Forex, which hold the same mechanical property of ice. Experiments have been conducted using monochromatic as well as random wave fields with different steepness and wavelengths (both shorter and larger than the floe). The wave field has been monitored before and after the simulated ice floe with a number of wave probes deployed along the basin, including a 6-probe array to track directional properties. On the whole, results show a substantial scattering and dissipation of the wave field, which appears to be dependent on the amount of overwash on the ice floe.

Cavaliere, Claudio; Alberello, Alberto; Bennetts, Luke; Meylan, Mike; Babanin, Alexander; Malavasi, Stefano; Toffoli, Alessandro

2014-05-01

344

Redox-sensitivity and mobility of selected pharmaceutical compounds in a laboratory column experiment  

NASA Astrophysics Data System (ADS)

Laboratory column experiments are suitable to investigate the sediment water interaction and to study the transport behaviour of solutes. Processes like retardation and degradation can be identified and quantified. The conducted experiment, which is closely connected to a field study in Luxembourg, investigated the transport behaviour of selected pharmaceutical compounds and their redox-dependent metabolism under water saturated conditions. Fine-grained natural sediment with a low hydraulic conductivity from a study site in Luxembourg was filled into the column. The water for the experiment was taken from a small stream at the same fieldsite. It was spiked with four pharmaceutical compounds (carbamazepine, diclofenac, ibuprofen, sulfamethoxazole) with concentrations between 170 and 300 ng/L for the different substances. The chosen pharmaceuticals were also detected in groundwater and surface water samples at the study site and used to qualify exchange/mixing of surface water and groundwater (BANZHAF et al., 2011). As some of the substances are known to exhibit redox-sensitive degradation, the redox-conditions were systematically varied throughout the experiment. This was realised by adding nitrate at the inflow of the column. During the experiment, which lasted for 2.5 months, four different nitrate concentrations (20-130 mg/L) were applied, beginning with the highest concentration. During the experiment water from the reservoir tank was sampled daily in order to detect a potential degradation of the pharmaceutical compounds before they enter the column. The effluent water was sampled every three hours to guarantee a maximum resolution for the analysis of the pharmaceuticals where necessary. In addition, major ions were analysed in the influent and effluent samples. Throughout the experiment physicochemical parameters (oxidation reduction potential (ORP), dissolved oxygen, electrical conductivity, and pH-value) were measured and logged at the outflow of the column. At the beginning, the ORP was positive (200 mV) and then dropped continuously. Negative values were reached after 1 month and at the end of the experiment -300 mV were measured. Apart from nitrate and nitrite no significant changes in ion concentrations were detected in the effluent. However, the added pharmaceuticals showed very different behaviour in the column. Diclofenac and especially carbamazepine were highly absorbed by the sediment. They were detected significantly later at the outflow of the column than sulfamethoxazole and ibuprofen. Sulfamethoxazole was heavily influenced by the redox-conditions. Its time variation curve in the effluent is negatively correlated with nitrite and nitrate: during nitrite formation the concentrations of sulfamethoxazole dropped considerably. The presented experiment yields a better understanding of the processes influencing the occurrence and transport behaviour of the studied compounds. In addition, some general findings on redox-dependent transport behaviour and metabolism of the antibiotic sulfamethoxazole are gained. This emphasizes the role of the ORP as a key parameter for the behaviour of this compound, which has to be considered. BANZHAF, S., KREIN, A. & SCHEYTT, T. (2011). Investigative approaches to determine exchange processes in the hyporheic zone of a low permeability riverbank. Hydrogeology Journal 19 (3), pp. 591-601.

Banzhaf, S.; Nödler, K.; Licha, T.; Krein, A.; Scheytt, T.

2012-04-01

345

Closing the loop on improvement: Packaging experience in the Software Engineering Laboratory  

NASA Technical Reports Server (NTRS)

As part of its award-winning software process improvement program, the Software Engineering Laboratory (SEL) has developed an effective method for packaging organizational best practices based on real project experience into useful handbooks and training courses. This paper shares the SEL's experience over the past 12 years creating and updating software process handbooks and training courses. It provides cost models and guidelines for successful experience packaging derived from SEL experience.

Waligora, Sharon R.; Landis, Linda C.; Doland, Jerry T.

1994-01-01

346

Investigating the impact of vegetation on alluvial fans using laboratory experiments  

NASA Astrophysics Data System (ADS)

Riparian vegetation can significantly influence the geomorphology of fluvial systems, affecting channel geometry and flow dynamics. However, there is still limited understanding of the role vegetation plays in the development of alluvial fans, despite the large number of vegetated fans located in temperate and humid climates. An understanding of the feedback loops between water flow, sediment dynamics and vegetation is key to understanding the geomorphological response of alluvial fans. But it is difficult to investigate these relationships in the natural world due to the complexity of the geomorphic and biological processes and timescales involved, whereas the controlled conditions afforded by laboratory experiments provide the ideal opportunity to explore these relationships. To examine the effects of vegetation on channel form, flow dynamics and morphology during fan evolution, a series of experiments were conducted using the Total Environment Simulator at the Deep, an experimental facility operated by the University of Hull. The experiments followed a 'similarity of processes' approach and so were not scaled to a specific field prototype. Live vegetation (Medicago Sativa) was used to simulate the influence of vegetation on the fan development. A range of experiments were conducted on fan plots 2x2m in size, the same initial conditions and constant water discharge and sediment feed rates were used, but the vegetation density and amount of geomorphic time (when the sediment and water were running and there was active fan development) between seeding / vegetation growth varied between runs. The fan morphology was recorded at regular intervals using a laser scanner (at 1mm resolution) and high resolution video recording and overhead photography were used to gain near-continuous data quantifying fan topography, flow patterns, channel migration and avulsion frequency. Image analysis also monitored the spatial extent of vegetation establishment. The use of these techniques allowed collection of high resolution spatial and temporal data on fan development with minimal disruption to the experiments. Results indicate that vegetation has a major influence on fan morphology and flow conditions; creating steeper and shorter fans, whilst also reducing the number of active channels and lowering the lateral migration rate. Vegetation also impacted avulsion behaviour by reducing the frequency of avulsion events, but increasing the magnitude of the events that occurred.

Clarke, Lucy; McLelland, Stuart; Coulthard, Tom

2014-05-01

347

Unstable Diffusion Layers: Laboratory Experiments on Carbon Sequestration Phenomena  

NASA Astrophysics Data System (ADS)

The sequestration of carbon dioxide in aqueous porous media involves a process where the initial formation of diffusion layers subsequently becomes unstable with respect to fingering. We will present experimental examples of this transient growth process from mass diffusion to fingering instability using a pair of fluids that mimic the behavior of carbon dioxide and salt water (brine), namely water and propylene glycol. In this experiment, performed in a Hele-Shaw cell, the permeability is adjusted by the plate thickness, the porosity is unity, and the Rayleigh number depends on the cell height. The diffusion layer and the fingers are visualized using optical shadowgraph techniques. We obtain the time evolution of the selected pattern wavelength, the distribution and scaling of the plume velocities, and the mass transfer rates for Ra in the range 5000 to 90,000 and for permeabilities in the range 5-20 x10-5cm^2. Comparisons with linear stability calculations and implications for carbon sequestration are discussed.

Ecke, Robert; Backhaus, Scott; Turitsyn, Konstantin

2010-11-01

348

The LBL (Lawrence Berkeley Laboratory) multiple beam experiments  

SciTech Connect

The multiple-beam induction linac approach to a heavy ion driver for inertial confinement, fusion features continuous current amplification along the accelerator and a minimum of beam manipulations from source to pellet. Current amplification and bunch length control require careful shaping of the accelerating voltages. MBE-4 is designed as a four-beam induction linac that models much of the accelerator physics of the electrostatically focused section of a significantly longer induction accelerator. Four space-charge-dominated Cs/sup +/ beams, initially about one meter in length at a current of 13 mA, are focused by electrostatic quadrupoles and accelerated in parallel from 200 to nearly 600 keV. The energy will reach approximately one MeV when the accelerator is complete. Experiments have proceeded in parallel with the construction of the apparatus which began in FY 85 and is now more than half complete. The results show a current amplification, so far, by a factor of 2.8 in good agreement with the longitudinal acceleration calculations.

Fessenden, T.J.; Keefe, D.; Kim, C.; Meuth, H.; Warwick, A.

1987-03-01

349

On the Successful Use of Inquiry-Driven Experiments in the Organic Chemistry Laboratory  

NASA Astrophysics Data System (ADS)

The inquiry-driven approach to laboratory teaching allows students to participate effectively in the process of science. This article provides examples of guided-inquiry and design-based experiments and explores strategies for implementing them to enliven the modern organic chemistry teaching laboratory in a variety of educational environments. We discuss factors important to the success of inquiry-driven experiments and projects in four categories of institutions, as well as the potential difficulties in implementing them, including faculty participation, TA training, post-laboratory discussions, instrumentation, and necessary background materials.

Mohrig, Jerry R.; Noring Hammond, Christina; Colby, David A.

2007-06-01

350

A geophysical perspective on mantle water content and melting: Inverting electromagnetic sounding data using laboratory-based electrical conductivity profiles  

NASA Astrophysics Data System (ADS)

This paper applies electromagnetic sounding methods for Earth's mantle to constrain its thermal state, chemical composition, and "water" content. We consider long-period inductive response functions in the form of C-responses from four stations distributed across the Earth (Europe, North America, Asia and Australia) covering a period range from 3.9 to 95.2 days and sensitivity to ~ 1200 km depth. We invert C-responses directly for thermo-chemical state using a self-consistent thermodynamic method that computes phase equilibria as functions of pressure, temperature, and composition (in the Na2O-CaO-FeO-MgO-Al2O3-SiO2 model system). Computed mineral modes are combined with recent laboratory-based electrical conductivity models from independent experimental research groups (Yoshino (2010) and Karato (2011)) to compute bulk conductivity structure beneath each of the four stations from which C-responses are estimated. To reliably allocate water between the various mineral phases we include laboratory-measured water partition coefficients for major upper mantle and transition zone minerals. This scheme is interfaced with a sampling-based algorithm to solve the resulting non-linear inverse problem. This approach has two advantages: (1) It anchors temperatures, composition, electrical conductivities, and discontinuities that are in laboratory-based forward models, and (2) At the same time it permits the use of geophysical inverse methods to optimize conductivity profiles to match geophysical data. The results show lateral variations in upper mantle temperatures beneath the four stations that appear to persist throughout the upper mantle and parts of the transition zone. Calculated mantle temperatures at 410 and 660 km depth lie in the range 1250-1650 °C and 1500-1750 °C, respectively, and generally agree with the experimentally-determined temperatures at which the measured phase reactions olivine ? ?-spinel and ?-spinel ? ferropericlase + perovskite occur. The retrieved conductivity structures beneath the various stations tend to follow trends observed for temperature with the strongest lateral variations in the uppermost mantle; for depths > 300 km conductivities appear to depend less on the particular conductivity database. Conductivities at 410 km and at 660 km depth are found to agree overall with purely geophysically-derived global and semi-global one-dimensional conductivity models. Both electrical conductivity databases point to < 0.01 wt.% H2O in the upper mantle. For transition zone minerals results from the laboratory database of Yoshino (2010) suggest that a much higher water content (up to 2 wt.% H2O) is required than in the other database (Karato, 2011), which favors a relatively "dry" transition zone (< 0.01 wt.% H2O). Incorporating laboratory measurements of hydrous silicate melting relations and available conductivity data allows us to consider the possibility of hydration melting and a high-conductivity melt layer above the 410-km discontinuity. The latter appears to be 1) regionally localized and 2) principally a feature from the Yoshino (2010) database. Further, there is evidence of lateral heterogeneity: The mantle beneath southwestern North America and central China appears "wetter" than that beneath central Europe or Australia.

Khan, A.; Shankland, T. J.

2012-02-01

351

Crossing over: The lived experiences of clinical laboratory science education teachers as they transition from traditional to online instruction  

NASA Astrophysics Data System (ADS)

A phenomenological study was undertaken to understand and describe the nature and meaning of the live experiences of faculty transition from traditional to teaching online clinical laboratory science courses. In order to gain insight into the lived experiences of faculty, in-depth interviews were conducted with 10 faculty members. The task of the researcher was to allow the participants to speak for themselves, and reveal the meaning of the experiences, rather than to discover causal connections or patterns of correlation. The key criterion in choosing purposeful sampling procedure was to obtain the deepest understanding possible of the lived experiences of faculty transitioning to online teaching, which were likely to be a rich source of the data of interest. Analyses of the interview text were based on three essential considerations. The three essential considerations were (a) the traditional role of the faculty, (b) factors affecting the changing role of the faculty, and (c) the effects of web-based technology on teaching role.

Veldkamp, Ruth B.

352

Laboratory experiments on liquid fragmentation during Earth's core formation  

NASA Astrophysics Data System (ADS)

Buoyancy-driven fragmentation of one liquid in another immiscible liquid likely occurred on a massive scale during the formation of the Earth, when dense liquid metal blobs were released within deep molten silicate magma oceans. Another example of this phenomenon is the sudden release of petroleum into the ocean during the Deepwater Horizon disaster (Gulf of Mexico, 2010). We present experiments on the instability and fragmentation of blobs of a heavy liquid released into a lighter immiscible liquid. During the fragmentation process, we observe deformation of the released fluid, formation of filamentary structures, capillary instability, and eventually drop formation. We find that, at low and intermediate Weber numbers (which measures the importance of inertia versus surface tension), the fragmentation regime mainly results from the competition between a Rayleigh-Taylor instability and the roll-up of a vortex ring. At sufficiently high Weber numbers (the relevant regime for core formation), the fragmentation process becomes turbulent. The large-scale flow then behaves as a turbulent vortex ring or a turbulent thermal: it forms a coherent structure whose shape remains self-similar during the fall and which grows by turbulent entrainment of ambient fluid. An integral model based on the entrainment assumption, and adapted to buoyant vortex rings with initial momentum, is consistent with our experimental data. This indicates that the concept of turbulent entrainment is valid for non-dispersed immiscible fluids at large Weber and Reynolds numbers. Series of photographs, turbulent fragmentation regime, time intervals of about 0.2 s. Portions (red boxes) have been magnified (on the right).

Landeau, M.; Deguen, R.; Olson, P.

2013-12-01

353

Results from the LDEF/A0076 Cascaded Variable Conductance Heatpipe Experiment.  

National Technical Information Service (NTIS)

The A0076 Variable Conductance Heat Pipe Experiment (CVCHPE) on the Long Duration Exposure Facility (LDEF) demonstrated temperature control better than +/- 0.3 C during fifty days on on-orbit data collection in a widely varying external environment. The e...

M. G. Grote

1992-01-01

354

World's Oldest Cotton Experiment: Relationships between Soil Chemical and Physical Properties and Apparent Electrical Conductivity  

Microsoft Academic Search

Measuring and mapping apparent soil electrical conductivity (ECa) is a potentially useful tool for delineating soil variability. The “Old Rotation,” the world's oldest continuous cotton (Gossypium hirsutum L.) experiment (ca. 1896), provides a valuable resource for evaluating soil spatial variability. The objectives of this study were to determine the relationship between soil chemical and physical properties and ECa in the

D. W. Reeves; J. N. Shaw; C. C. Mitchell

2006-01-01

355

Biomass fire consumption and carbon release rates of rainforestclearing experiments conducted in northern Mato Grosso, Brazil  

Microsoft Academic Search

Biomass consumption and carbon release rates during the process of forest clearing by fire in five test plots are presented and discussed. The experiments were conducted at the Caiabi Farm, near the town of Alta Floresta, state of Mato Grosso, Brazil, in five square plots of 1 ha each, designated A, B, C, D, and E, with different locations and

João A. Carvalho Jr; Fernando S. Costa; Carlos A. Gurgel Veras; David V. Sandberg; Ernesto C. Alvarado; Ralf Gielow; Aguinaldo M. Serra Jr; José C. Santos

2001-01-01

356

Cool in the Kitchen: Radiation, Conduction, and the Newton "Hot Block" Experiment.  

ERIC Educational Resources Information Center

Discusses the history of the development of Newton's Law of Cooling. Describes an experiment conducted in the kitchen that is designed to test the rate of cooling of a hot block of iron. Finds that Newton's law does not represent very well the mechanism of heat loss. (Contains over 10 references.) (WRM)

Silverman, Mark P.; Silverman, Christopher R.

2000-01-01

357

Analysis of Data Acquired During Shallow Water Experiments Conducted in 2006 and 2011.  

National Technical Information Service (NTIS)

Shallow Water 2006 experiment was conducted in a region off the New Jersey coast where nonlinear internal wave activity is known to occur and this resulting in range-dependent sound speed profiles in the water column. In continuation of the work on estima...

S. D. Rajan

2012-01-01

358

Estimating the hydraulic conductivity of slowly permeable and swelling materials from single-ring experiments  

NASA Astrophysics Data System (ADS)

The in situ determination of the field-saturated hydraulic conductivity of low-permeability porous materials is a major concern for both geotechnics and soil physics with regards to environmental protection or water resources management. Recent early-time single-ring infiltration experiments, involving sequential constant head and falling head conditions, allow its efficient estimation. Nevertheless, the theory on which the interpretation was based was still strictly valid to nondeformable soils and implicity relied on a particular form of the hydraulic conductivity-soil water pressure head relationship. This theory is now extended to deformable materials, without any restrictive hypothesis. A new concept, bulk sorptivity, which characterizes the solid phase movement, is introduced. Field experiments, conducted on two liners of swelling and slowly permeable materials, revealed that neglecting the soil deformation induces an underestimation of the actual coefficient of permeability of the soil.

GéRard-Marchant, P.; Angulo-Jaramillo, R.; Haverkamp, R.; Vauclin, M.; Groenevelt, P.; Elrick, D. E.

1997-06-01

359

Ground-Laboratory to In-Space Atomic Oxygen Correlation for the Polymer Erosion and Contamination Experiment (PEACE) Polymers  

NASA Technical Reports Server (NTRS)

The Materials International Space Station Experiment 2 (MISSE 2) Polymer Erosion and Contamination Experiment (PEACE) polymers were exposed to the environment of low Earth orbit (LEO) for 3.95 years from 2001 to 2005. There were 41 different PEACE polymers, which were flown on the exterior of the International Space Station (ISS) in order to determine their atomic oxygen erosion yields. In LEO, atomic oxygen is an environmental durability threat, particularly for long duration mission exposures. Although spaceflight experiments, such as the MISSE 2 PEACE experiment, are ideal for determining LEO environmental durability of spacecraft materials, ground-laboratory testing is often relied upon for durability evaluation and prediction. Unfortunately, significant differences exist between LEO atomic oxygen exposure and atomic oxygen exposure in ground-laboratory facilities. These differences include variations in species, energies, thermal exposures and radiation exposures, all of which may result in different reactions and erosion rates. In an effort to improve the accuracy of ground-based durability testing, ground-laboratory to in-space atomic oxygen correlation experiments have been conducted. In these tests, the atomic oxygen erosion yields of the PEACE polymers were determined relative to Kapton H using a radio-frequency (RF) plasma asher (operated on air). The asher erosion yields were compared to the MISSE 2 PEACE erosion yields to determine the correlation between erosion rates in the two environments. This paper provides a summary of the MISSE 2 PEACE experiment; it reviews the specific polymers tested as well as the techniques used to determine erosion yield in the asher, and it provides a correlation between the space and ground laboratory erosion yield values. Using the PEACE polymers asher to in-space erosion yield ratios will allow more accurate in-space materials performance predictions to be made based on plasma asher durability evaluation.

Stambler, Arielle H.; Inoshita, Karen E.; Roberts, Lily M.; Barbagallo, Claire E.; deGroh, Kim K.; Banks, Bruce A.

2011-01-01

360

DEMONSTRATION SOLIDIFICATION TESTS CONDUCTED ON RADIOACTIVELY CONTAMINATED ORGANIC LIQUIDS AT THE AECL WHITESHELL LABORATORIES  

SciTech Connect

The AECL, Whiteshell Laboratory (WL) near Pinawa Manitoba, Canada, was established in the early 1960's to carry out AECL research and development activities for higher temperature versions of the CANDU{reg_sign} reactor. The initial focus of the research program was the Whiteshell Reactor-1 (WR-1) Organic Cooled Reactor (OCR) that began operation in 1965. The OCR program was discontinued in the early 1970's in favor of the successful heavy-water-cooled CANDU system. WR-1 continued to operate until 1985 in support of AECL nuclear research programs. A consequence of the Federal government's recent program review process was AECL's business decision to discontinue research programs and operations at the Whiteshell Laboratories and to consolidate its' activities at the Chalk River Laboratories. As a result, AECL received government concurrence in 1998 to proceed to plan actions to achieve closure of WL. The planning actions now in progress address the need to safely and effectively transition the WL site from an operational state, in support of AECL's business, to a shutdown and decommissioned state that meets the regulatory requirements for a licensed nuclear site. The decommissioning program that will be required at WL is unique within AECL and Canada since it will need to address the entire research site rather than individual facilities declared redundant. Accordingly, the site nuclear facilities are being systematically placed in a safe shutdown state and planning for the decommissioning work to place the facilities in a secure monitoring and surveillance state is in progress. One aspect of the shutdown activities is to deal with the legacy of radioactively contaminated organic liquid wastes. Use of a polymer powder to solidify these organic wastes was identified as one possibility for improved interim storage of this material pending final disposition.

Ryz, R. A.; Brunkow, W. G.; Govers, R.; Campbell, D.; Krause, D.

2002-02-25

361

In-house experiments in large space structures at the Air Force Wright Aeronautical Laboratories Flight Dynamics Laboratory  

NASA Technical Reports Server (NTRS)

The Flight Dynamics Laboratory is committed to an in-house, experimental investigation of several technical areas critical to the dynamic performance of future Air Force large space structures. The advanced beam experiment was successfully completed and provided much experience in the implementation of active control approaches on real hardware. A series of experiments is under way in evaluating ground test methods on the 12 meter trusses with significant passive damping. Ground simulated zero-g response data from the undamped truss will be compared directly with true zero-g flight test data. The performance of several leading active control approaches will be measured and compared on one of the trusses in the presence of significant passive damping. In the future, the PACOSS dynamic test article will be set up as a test bed for the evaluation of system identification and control techniques on a complex, representative structure with high modal density and significant passive damping.

Gordon, Robert W.; Ozguner, Umit; Yurkovich, Steven

1989-01-01

362

Laboratory Experiments on the Electrochemical Remediation of the Environment. Part 8. Microscale Simultaneous Photocatalysis  

ERIC Educational Resources Information Center

A microscale experiment in which the simultaneous oxidation of an organic compound and the reduction of a metal ion are photocatalytically performed in an aqueous slurry containing TiO[subscript 2] irradiated with UV light. This experiment can be performed in the laboratory session with simple chemicals and equipments.

Ibanez, Jorge G.; Mena-Brito, Rodrigo; Fregoso-Infante, Arturo

2005-01-01

363

What's New in the Launching of Start-Ups? Features and Implications of Laboratory Experiments  

ERIC Educational Resources Information Center

This article responds to "Laboratory experiments as a tool in the empirical economic analysis of high-expectation start-ups" by Martin Curley and Piero Formica, published in the December 2008 issue of "Industry and Higher Education." The exploitation of knowledge and experience is increasingly important to companies operating in the globalized…

Matricano, Diego

2009-01-01

364

The Equilibrium Constant for Bromothymol Blue: A General Chemistry Laboratory Experiment Using Spectroscopy  

ERIC Educational Resources Information Center

A simple, inexpensive, and environmentally friendly undergraduate laboratory experiment is described in which students use visible spectroscopy to determine a numerical value for an equilibrium constant, K[subscript c]. The experiment correlates well with the lecture topic of equilibrium even though the subject of the study is an acid-base…

Klotz, Elsbeth; Doyle, Robert; Gross, Erin; Mattson, Bruce

2011-01-01

365

Connecting Solubility, Equilibrium, and Periodicity in a Green, Inquiry Experiment for the General Chemistry Laboratory  

ERIC Educational Resources Information Center

We present a novel first-year chemistry laboratory experiment that connects solubility, equilibrium, and chemical periodicity concepts. It employs a unique format that asks students to replicate experiments described in different sample lab reports, each lacking some essential information, rather than follow a scripted procedure. This structure is…

Cacciatore, Kristen L.; Amado, Jose; Evans, Jason J.; Sevian, Hannah

2008-01-01

366

Advanced Undergraduate-Laboratory Experiment on Electron Spin Resonance in Single-Crystal Ruby  

ERIC Educational Resources Information Center

An electron-spin-resonance experiment which has been successfully performed in an advanced undergraduate physics laboratory is described. A discussion of that part of the theory of magnetic resonance necessary for the understanding of the experiment is also provided in this article. (DT)

Collins, Lee A.; And Others

1974-01-01

367

An Investigation of Students' Prior Experience with Laboratory Practicals and Report-Writing.  

ERIC Educational Resources Information Center

A study of 723 University of Cape Town (South Africa) physics students investigated their prior experience with laboratory procedures and technical report writing. Results suggest that, although students are generally aware of the importance of these elements of learning, school experience with teaching of scientific concepts and skills is often…

Kaunda, L.; Ball, D.

1998-01-01

368

Long-term diffusion experiment at Mont Terri: first results from field and laboratory data  

Microsoft Academic Search

The diffusion of radionuclides is an important safety aspect for nuclear waste disposal in argillaceous host rocks. A long-term diffusion experiment, termed DI-A, is being carried out at the Mont Terri Rock Laboratory in the Opalinus Clay formation. The aim of this experiment is the understanding of the migration and sorption behaviour of cationic and anionic species in consolidated clays.

P. Wersin; L. R. Van Loon; J. M. Soler; A. Yllera; J. Eikenberg; Th. Gimmi; P. Hernán; J.-Y. Boisson

2004-01-01

369

Annotated List of Chemistry Laboratory Experiments with Computer Access. Final Report.  

ERIC Educational Resources Information Center

Project Chemlab was designed to prepare an "Annotated List of Laboratory Experiments in Chemistry from the Journal of Chemical Education (1957-1979)" and to develop a computer file and program to search for specific types of experiments. Provided in this document are listings (photoreduced copies of printouts) of over 1500 entries classified into…

Bunce, S. C.; And Others

370

Topics in Chemical Instrumentation: XCVIII. Experiments Involving Thermal Methods of Analysis for Undergraduate Chemistry Laboratories.  

ERIC Educational Resources Information Center

Explains some experiments involving thermal methods of analysis for undergraduate chemistry laboratories. Some experiments are: (1) the determination of the density and degree of crystallinity of a polymer; and (2) the determination of the specific heat of a nonvolatile compound. (HM)

Ewing, Galen W., Ed.

1978-01-01

371

Characterization of blocks impacts from elastic waves: insights from laboratory experiments  

NASA Astrophysics Data System (ADS)

Rockfalls, debris flows and rock avalanches constitute a major natural hazard for the population in mountainous, volcanic and coastal areas but their direct observation on the field is very dangerous. Recent studies showed that gravitational instabilities can be detected and characterized (volume, duration,...) thanks to the seismic signal they generate. In an avalanche, individual block bouncing and rolling on the ground are expected to generated signals of higher frequencies than the main flow spreading. The identification of the time/frequency signature of individual blocks in the recorded signal remains however difficult. Laboratory experiments were conducted to investigate the acoustic signature of diverse simple sources corresponding to grains falling over thin plates of plexiglas and rock blocks. The elastic energy emitted by a single bouncing steel bead into the support was first quantitatively estimated and compared to the potential energy of fall and to the potential energy change during the shock. Next, we consider the collapse of granular columns made of steel spherical beads onto hard substrates. Initially, these columns were held by a magnetic field allowing to suppress suddenly the cohesion between the beads, and thus to minimize friction effects that would arise from side walls. We varied systematically the column volume, the column aspect ratio (height over length) and the grain size. This is shown to affect the signal envelope and frequency content. In the experiments, two types of acoustic sensors were used to record the signals in a wide frequency range: accelerometers (1 Hz to 56 kHz) and piezoelectric sensors (100 kHz to 1 MHz). The experiments were also monitored optically using fast cameras. We developed a technique to use quantitatively both types of sensors to evaluate the elastic energy emitted by the sources. Eventually, we looked at what types of features in the signal are affected by individual shocks or by the large scale geometry of the avalanche.

Farin, M.; Mangeney, A.; Toussaint, R.; De Rosny, J.; Shapiro, N.

2013-12-01

372

Characterization of blocks impacts from acoustic emissions: insights from laboratory experiments  

NASA Astrophysics Data System (ADS)

Rockfalls, debris flows and rock avalanches represent a major natural hazard for the population in mountainous, volcanic and coastal areas but their direct observation on the field is very dangerous. Recent studies showed that gravitational instabilities can be detected and characterized (volume, duration,...) thanks to the seismic signal they generate. In an avalanche, individual block bouncing and rolling on the ground are expected to generated signals of higher frequencies than the main flow spreading. The identification of the time/frequency signature of individual blocks in the recorded signal remains however difficult. Laboratory experiments were conducted to investigate the acoustic signature of diverse simple sources corresponding to grains falling over thin plates of plexiglas and glass and over rock blocks. The elastic energy emitted by a single bouncing bead into the support was first quantitatively estimated and compared to the potential energy of fall and to the potential energy change during the shock. We obtained simple scaling laws relating the impactor characteristics (size, height of fall, material,...) to the elastic energy and spectral content. Next, we consider the collapse of granular columns made of steel spherical beads onto hard substrates. Initially, these columns were held by a magnetic field allowing to suppress suddenly the cohesion between the beads, and thus to minimize friction effects that would arise from side walls. We varied systematically the column volume, the column aspect ratio (height over length) and the grain size. This is shown to affect the signal envelope and frequency content. In the experiments, accelerometers (1 Hz to 56 kHz) were used to record the signals in a wide frequency range. The experiments were also monitored optically using fast cameras. Eventually, we looked at what types of features in the signal are affected by individual impacts, rolling of beads or by the large scale geometry of the avalanche.

Farin, Maxime; Mangeney, Anne; de Rosny, Julien; Toussaint, Renaud; Shapiro, Nikolaï

2014-05-01

373

Physical barriers formed from gelling liquids: 1. numerical design of laboratory and field experiments  

SciTech Connect

The emplacement of liquids under controlled viscosity conditions is investigated by means of numerical simulations. Design calculations are performed for a laboratory experiment on a decimeter scale, and a field experiment on a meter scale. The purpose of the laboratory experiment is to study the behavior of multiple gout plumes when injected in a porous medium. The calculations for the field trial aim at designing a grout injection test from a vertical well in order to create a grout plume of a significant extent in the subsurface.

Finsterle, S.; Moridis, G.J.; Pruess, K.; Persoff, P.

1994-01-01

374

Undergraduates at Sea and in the Laboratory Conducting Habitat Mapping Using Multibeam and Sidescan Sonar  

NASA Astrophysics Data System (ADS)

During the last five years, undergraduate students at the College of Charleston have had numerous opportunities to take part in the college's Transect Program and sail aboard research vessels on 2-5 day cruises to study the continental shelf. The program's purpose is to train students in oceanographic research while developing a long-term information geodatabase to characterize and monitor essential fish habitats, and to map seafloor geomorphology. During these cruises students take the lead to conduct a variety of research investigations which include hydrographic surveys of the seafloor using sidescan sonar, multibeam bathymetry, and video collected using a remotely operated vehicle and during SCUBA dives. Following the data collection cruises, students have enrolled in semester-long research courses to analyze data and document results through poster and oral presentations. More than 60 students have taken part in at least one of 6 programs. In the past two years, the NOAA Ship NANCY FOSTER has provided invaluable sea time to conduct multibeam surveys of the mid- and outer continental shelf off Charleston, so that the 22 participating Transect students have focused their work on seafloor mapping, and have become trained in state-of-the art CARIS multibeam and sidescan sonar processing software. Most of these students have presented their results at professional meetings, and manuscripts are currently in preparation. Students have had numerous post-program opportunities to conduct further research at sea and in the lab. They have collaborated with NOAA scientists and other investigators, conducting bathymetry data processing and analysis from other regions. Most recently, two program graduates worked with University of Washington investigators to map sites for the Ocean Observatory Initiative Regional Scale Nodes. Several students have been contracted or hired as hydrographic survey technicians, while others have gone to graduate school to continue their work using these invaluable skills learned as undergraduates.

Sautter, L. R.; Harris, M. S.

2008-12-01

375

Plasma physics and environmental perturbation laboratory. [magnetospheric experiments from space shuttle  

NASA Technical Reports Server (NTRS)

Current work aimed at identifying the active magnetospheric experiments that can be performed from the Space Shuttle, and designing a laboratory to carry out these experiments is described. The laboratory, known as the PPEPL (Plasma Physics and Environmental Perturbation Laboratory) consists of 35-ft pallet of instruments connected to a 25-ft pressurized control module. The systems deployed from the pallet are two 50-m booms, two subsatellites, a high-power transmitter, a multipurpose accelerator, a set of deployable canisters, and a gimbaled instrument platform. Missions are planned to last seven days, during which two scientists will carry out experiments from within the pressurized module. The type of experiments to be performed are outlined.

Vogl, J. L.

1973-01-01

376

Interpretation of injection-withdrawal tracer experiments conducted between two wells in a large single fracture.  

PubMed

Tracer experiments conducted using a flow field established by injecting water into one borehole and withdrawing water from another are often used to establish connections and investigate dispersion in fractured rock. As a result of uncertainty in the uniqueness of existing models used for interpretation, this method has not been widely used to investigate more general transport processes including matrix diffusion or advective solute exchange between mobile and immobile zones of fluid. To explore the utility of the injection-withdrawal method as a general investigative tool and with the intent to resolve the transport processes in a discrete fracture, two tracer experiments were conducted using the injection-withdrawal configuration. The experiments were conducted in a fracture which has a large aperture (>500 microm) and horizontally pervades a dolostone formation. One experiment was conducted in the direction of the hydraulic gradient and the other in the direction opposite to the natural gradient. Two tracers having significantly different values of the free-water diffusion coefficient were used. To interpret the experiments, a hybrid numerical-analytical model was developed which accounts for the arcuate shape of the flow field, advection-dispersion in the fracture, diffusion into the matrix adjacent to the fracture, and the presence of natural flow in the fracture. The model was verified by comparison to a fully analytical solution and to a well-known finite-element model. Interpretation of the tracer experiments showed that when only one tracer, advection-dispersion, and matrix diffusion are considered, non-unique results were obtained. However, by using multiple tracers and by accounting for the presence of natural flow in the fracture, unique interpretations were obtained in which a single value of matrix porosity was estimated from the results of both experiments. The estimate of porosity agrees well with independent measurements of porosity obtained from core samples. This suggests that: (i) the injection-withdrawal method is a viable tool for the investigation of general transport processes provided all relevant experimental conditions are considered and multiple conservative tracers are used; and (ii) for the conditions of the experiments conducted in this study, the dominant mechanism for exchange of solute between the fracture and surrounding medium is matrix diffusion. PMID:15336796

Novakowski, K S; Bickerton, G; Lapcevic, P

2004-09-01

377

Surface Conductive Glass.  

ERIC Educational Resources Information Center

Discusses the properties of surface-conducting glass and the chemical nature of surface-conducting stannic (tin) oxide. Also provides the procedures necessary for the preparation of surface-conducting stannic oxide films on glass substrates. The experiment is suitable for the advanced inorganic chemistry laboratory. (JN)

Tanaka, John; Suib, Steven L.

1984-01-01

378

A Fast and Inexpensive Western Blot Experiment for the Undergraduate Laboratory  

NASA Astrophysics Data System (ADS)

Western blotting is an important, modern technique for transferring proteins from a gel onto nitrocellulose or other suitable support and then detecting a protein of interest using antibodies. We have developed an experiment and optimized the conditions for the undergraduate laboratory. The experiment can be done quickly using an electrophoretic blotter or more cheaply using passive transfer. This experiment allows the student to learn valuable procedures currently used in biochemistry and other biological sciences.

Farrell, Shawn O.; Farrell, Lynn E.

1995-08-01

379

Sediment-contact and survival of fingernail clams: Implications for conducting short-term laboratory tests  

USGS Publications Warehouse

Porewater toxicity tests have been used as indicators of whole sediment toxicity. However, many species commonly tested in porewater predominately reside in the water column and otherwise have little to no direct contact with sediment and associated porewater. We assessed the feasibility of porewater toxicity tests with fingernail clams Musculium transversum, a benthic macroinvertebrate that inhabits soft bottom sediments and feeds by filtering surface and porewater. Fingernail clams were exposed to water or sediment in a 96 h laboratory test with a 5 x 2 factorial experimental design. The five treatments included sediments from four sites in the Mississippi River and one sediment-free control (well water). In all treatments, clams were exposed to the sediments or water either directly (no enclosure) or indirectly (enclosure, suspended above the sediment surface). There were three replicates for each of the ten treatment combinations. Overall, survival of fingernail clams did not vary among the five treatments (p = 0.36). In treatments without enclosures, survival of clams in the sediment-free control was not significantly different (p = 0.34) from the sediment-containing treatments. Survival of clams in the sediment-free control averaged 85 - suggesting that direct sediment contact is not necessary for survival in short-term tests. In contrast, survival of clams in the sediment-containing treatments differed significantly (p = 0.03) between exposures with (mean, 77) and without (mean, 89) enclosures. Thus, fingernail clams may provide an alternative species for evaluating benthic macroinvertebrates in short-term laboratory porewater tests. However, more information on their physiological requirements and the development of sublethal endpoints is recommended before their use in tests of longer duration. (C) 2000 by John Wiley and Sons, Inc.

Naimo, T. J.; Cope, W. G.; Bartsch, M. R.

2000-01-01

380

Healing of snow interfaces: cold laboratory experiments on isothermal snow sintering  

NASA Astrophysics Data System (ADS)

Snow has the fastest sintering rate in geology, compared to any other earth material at similar pressures and temperatures. Due to this, sintering may play a crucial role in post-fracture healing of snowpack weak layers, which are prerequisites of avalanche release. The strength recovery of the latter is of interest for snow avalanche modeling focused on sub-critical weak layer fractures. However, it remains very poorly documented and studied. In this work, our main focus is on the fundamental physical property of simple flat snow interfaces to heal and regain their strength with time through sintering (at time scales up to 23 hours). We conducted a series of well controlled cold laboratory experiments (-10°C) with a newly developed shear apparatus and natural snow samples of different densities and grain types. Preliminary results of force-controlled shearing tests at various normal pressures (0-1kPa) showed the healing of snow interfaces, leading to a fast power-law recovery of their strength. The observed power-law dependency (mean exponent ~ 0.2) agrees with several other experimental and theoretical studies, which were based on homogeneous snow and different instrumental methods.

Podolskiy, E. A.; Barbero, M.; Barpi, F.; Borri-Brunetto, M.; Pallara, O.; Frigo, B.; Chiaia, B.; Chambon, G.; Naaim, M.

2013-12-01

381

Dynamics of soil water evaporation during soil drying: laboratory experiment and numerical analysis.  

PubMed

Laboratory and numerical experiments were conducted to investigate the evolution of soil water evaporation during a continuous drying event. Simulated soil water contents and temperatures by the calibrated model well reproduced measured values at different depths. Results show that the evaporative drying process could be divided into three stages, beginning with a relatively high evaporation rate during stage 1, followed by a lower rate during transient stage and stage 2, and finally maintaining a very low and constant rate during stage 3. The condensation zone was located immediately below the evaporation zone in the profile. Both peaks of evaporation and condensation rate increased rapidly during stage 1 and transition stage, decreased during stage 2, and maintained constant during stage 3. The width of evaporation zone kept a continuous increase during stages 1 and 2 and maintained a nearly constant value of 0.68?cm during stage 3. When the evaporation zone totally moved into the subsurface, a dry surface layer (DSL) formed above the evaporation zone at the end of stage 2. The width of DSL also presented a continuous increase during stage 2 and kept a constant value of 0.71?cm during stage 3. PMID:24489492

Han, Jiangbo; Zhou, Zhifang

2013-01-01

382

CUTANEOUS MANIFESTATIONS OF DEEP MYCOSIS: AN EXPERIENCE IN A TROPICAL PATHOLOGY LABORATORY  

PubMed Central

Background: Cutaneous manifestations of deep mycotic infection are fraught with delayed or misdiagnosis from mainly cutaneous neoplastic lesions. Aim: This study is designed to present our experience of these mycoses in a pathology laboratory in the tropics. Materials and Methods: A clinicopathologic analysis of deep mycotic infections was conducted over a 15 years period Formalin fixed and paraffin wax processed biopsies were stained with hematoxylin and eosin, periodic acid Schiff (PAS), and Grocott's methenamine silver (GMS) for the identification of fungus specie. Patients’ bio-data and clinical information were obtained from records. Results: Twenty males and seven females presented with 6 months to 6 years histories of varying symptoms of slow growing facial swellings, nodules, subcutaneous frontal skull swelling, proptosis, nasal blockage, epistaxis, discharging leg sinuses, flank mass, convulsion and pain. Of the 27 patients, four gave antecedent history of trauma, two had recurrent lesions which necessitated maxilectomy, two presented with convulsion without motor dysfunction while one had associated erosion of the small bones of the foot. None of the patients had debilitating illnesses such as diabetes mellitus, tuberculosis, and HIV infection. Tissue histology revealed histoplasmosis (10), mycetoma (9), subcutaneous phycomycosis (6), and phaeohyphomycosis (2). Conclusion: Deep mycoses may present primarily as cutaneous lesions in immunocompetent persons and often elicit distinct histologic inflammatory response characterized by granuloma formation. Diagnosis in resource constraint setting can be achieved with tissue stained with PAS and GMS which identifies implicated fungus. Clinical recognition and adequate knowledge of the pathology of these mycoses may reduce attendant patient morbidity.

Samaila, Modupeola Omotara; Abdullahi, Kabiru

2011-01-01

383

Infinite-dimensional approach to system identification of Space Control Laboratory Experiment (SCOLE)  

NASA Technical Reports Server (NTRS)

The identification of a unique set of system parameters in large space structures poses a significant new problem in control technology. Presented is an infinite-dimensional identification scheme to determine system parameters in large flexible structures in space. The method retains the distributed nature of the structure throughout the development of the algorithm and a finite-element approximation is used only to implement the algorithm. This approach eliminates many problems associated with model truncation used in other methods of identification. The identification is formulated in Hilbert space and an optimal control technique is used to minimize weighted least squares of error between the actual and the model data. A variational approach is used to solve the problem. A costate equation, gradients of parameter variations and conditions for optimal estimates are obtained. Computer simulation studies are conducted using a shuttle-attached antenna configuration, more popularly known as the Space Control Laboratory Experiment (SCOLE) as an example. Numerical results show a close match between the estimated and true values of the parameters.

Hossain, S. A.; Lee, K. Y.

1988-01-01

384

Improved understanding of bimolecular reactions in deceptively simple homogeneous media: From laboratory experiments to Lagrangian quantification  

NASA Astrophysics Data System (ADS)

heterogeneity affects reaction kinetics by controlling the mixing of reactant particles, but the linkage between medium properties and reaction kinetics is difficult to build, even for simple, relatively homogeneous media. This study aims to explore the dynamics of bimolecular reactions, aniline + 1,2-naphthoquinone-4-sulfonic acid ? 1,2-naphthoquinone-4-aminobenzene, in relatively homogeneous flow cells. Laboratory experiments were conducted to monitor the transport of both conservative and reactive tracers through columns packed with silica sand of specific diameters. The measured tracer breakthrough curves exhibit subdiffusive behavior with a late-time tail becoming more pronounced with decreasing sand size, probably due to the segregated flow regions formed more easily in columns packed with smaller size sand. Numerical analysis using a novel Lagrangian model shows that subdiffusion has a twofold effect on bimolecular reactions. While subdiffusion enhances the power-law growth rate of product mass by prolonging the exposure of reactant particles in the depletion zone, the global reaction rate is constrained because subdiffusion constrains the mobility of reactant particles. Reactive kinetics in deceptively simple homogeneous media is therefore controlled by subdiffusion, which is sensitive to the dimensions of packed sand.

Zhang, Yong; Qian, Jiazhong; Papelis, Charalambos; Sun, Pengtao; Yu, Zhongbo

2014-02-01

385

Numerical and laboratory experiments on the dynamics of plume-ridge interaction. Progress report  

SciTech Connect

Mantle plumes and passive upwelling beneath ridges are the two dominant modes of mantle transport and thermal/chemical fluxing between the Earth`s deep interior and surface. While plumes and ridges independently contribute to crustal accretion, they also interact and the dispersion of plumes within the upper mantle is strongly modulated by mid-ocean ridges. The simplest mode of interaction, with the plume centered on the ridge, has been well documented and modeled. The remaining question is how plumes and ridges interact when the plume is located off-axis; it has been suggested that a pipeline-like flow from the off-axis plume to the ridge axis at the base of the rigid lithosphere may develop. Mid-ocean ridges migrating away from hot mantle plumes can be affected by plume discharges over long times and ridge migration distances. Salient feature of this model is that off-axis plumes communicate with the ridge through a channel resulting from the refraction and dispersion of an axi-symmetric plume conduit along the base of the sloping lithosphere. To test the dynamics of this model, a series of numerical and laboratory dynamic experiments on the problem of a fixed ridge and an off-axis buoyant upwelling were conducted. Results are discussed.

Kincaid, C. [Rhode Island Univ., Kingston, RI (United States). Graduate School of Oceanography; Gable, C.W. [Los Alamos National Lab., NM (United States)

1995-09-01

386

Zero-gravity cloud physics laboratory: Candidate experiments definition and preliminary concept studies  

NASA Technical Reports Server (NTRS)

The candidate definition studies on the zero-g cloud physics laboratory are covered. This laboratory will be an independent self-contained shuttle sortie payload. Several critical technology areas have been identified and studied to assure proper consideration in terms of engineering requirements for the final design. Areas include chambers, gas and particle generators, environmental controls, motion controls, change controls, observational techniques, and composition controls. This unique laboratory will allow studies to be performed without mechanical, aerodynamics, electrical, or other type techniques to support the object under study. This report also covers the candidate experiment definitions, chambers and experiment classes, laboratory concepts and plans, special supporting studies, early flight opportunities and payload planning data for overall shuttle payload requirements assessments.

Eaton, L. R.; Greco, R. V.; Hollinden, A. B.

1973-01-01

387

Promoting Student Involvement with Environmental Laboratory Experiments in a General Microbiology Course  

PubMed Central

This is a descriptive study of a series of laboratory exercises on environmental microbiology carried out by students in a general microbiology course during eight of the twelve weeks of the semester. The revised laboratory component is predicated upon seawater and sediment samples collected by student pairs using marine sampling equipment on a field trip aboard a research vessel. Two longitudinal studies were performed: assay for antibiotic production from isolated actinomycetes and construction and observation of Winogradsky columns. Two additional experiments: culturing microalgae and water testing for coliforms also used the samples collected by the students. The advantages of long-term, challenging laboratory experiences actively involving the students in group process, self-direction, and scientific practices are discussed. Also considered are development of laboratory skills, scientific competencies, and students’ self-confidence in carrying out such environmental investigations. Plans for future assessment of student learning are presented.

TARAS, LORETTA BRANCACCIO

2003-01-01

388

THE IPOS FRAMEWORK: LINKING FISH SWIMMING PERFORMANCE IN ALTERED FLOWS FROM LABORATORY EXPERIMENTS TO RIVERS  

SciTech Connect

Current understanding of the effects of turbulence on the swimming performance of fish 32 is primarily derived from laboratory experiments under pressurized flow swim tunnels 33 and open channel flow facilities. These studies have produced valuable information on 34 the swimming mechanics and behavior of fish in turbulent flow. However, laboratory 35 studies have limited representation of the flows fish experience in nature. The complex 36 flow structure in rivers is imparted primarily by the highly heterogeneous and non37 uniform bed and planform geometry. Our goal is to direct future laboratory and field 38 studies to adopt a common framework that will shape the integration of both approaches. 39 This paper outlines four characteristics of turbulent flow, which we suggest should be 40 evaluated when generalizing results from fish turbulent studies in both the laboratory and 41 the field. The framework is based on four turbulence characteristics that are summarized 42 under the acronym IPOS: Intensity, Periodicity, Orientation, and Scale.

Neary, Vincent S [ORNL

2011-01-01

389

Laboratory experiment on the determination of radiostrontium transfer parameter in water - fish compartment system.  

PubMed

A laboratory experiment was conducted to investigate the water - fish transfer parameter of radiostrontium that potentially contaminate human body through water - fish - human pathway in the nuclear accident cases. In this experiment, carp fish (Cyprinus carpio), generally produced and consumed by Indonesian people, were cultured in a tank filled with 500 L water contaminated with (85)Sr for two months. The observation of fish growth and radioactivity were conducted every five days by taking up three fish and water samples. The fish were dissected and separated into muscle, bones and internally organ, then destructed using chloric acid. The fish and water samples were then measured using gamma spectrometer with HPGe detector. The transfer parameter of transfer factor (T(f)), uptake rate constant (u), elimination rate constant (k), and the effective half life (T(e)) were analyzed by mathematical equations. The high (85)Sr concentration was observed in the bone by the T(f) value of 67.99 ± 9.68 mL g(-1) wet weight, whereas the concentration in muscle and internal organ were lower with the T(f) of 26.05 ± 4.44 mL g(-1) wet weight and 16.95 ± 2.34 mL g(-1) wet weight, respectively. The values of u obtained from the mathematical calculation were 0.025 day(-1), 0.029 day(-1), and 0.04 day(-1) for bone, muscle, and internal organ, respectively. Those values were higher compared to the k values, i.e. 0.018 day(-1), 0.025 day(-1), and 0.022 day(-1) indicating the accumulation were take place in bone, muscle, and internal organ. The effective half life, which is the sum of physical and biological half life, of (85)Sr in carp was about 30 days. The transfer parameter values determined from this experiment can be used in internal radiation doses assessment through water - fish - human pathways in case of radiostrontium contamination in freshwater environment, so a recommendation can be considered relating to the fish consumption during or after radiostrontium release to the environment. PMID:22306861

Tjahaja, Poppy Intan; Sukmabuana, Putu; Siti Salami, Indah Rahmatiah; Muntalif, Barti Setiani

2012-07-01

390

STS-47 Payload Specialist Mohri conducts visual stability experiment in SLJ  

NASA Technical Reports Server (NTRS)

STS-47 Payload Specialist Mamoru Mohri, using the light impulse stimulation experiment hardware, conducts Comparative Measurement of Visual Stability in Earth and Cosmic Space (VISUAL STABILITY). The hardware is set up in the forward section of the Spacelab Japan (SLJ) science module aboard the Earth-orbiting Endeavour, Orbiter Vehicle (OV) 105. The experiment will investigate the lack of eye, head, and body coordination as a possible contributor to space adaptation syndrome (SAS). Electrodes attached to Mohri record his eye movements and neck tension as he tracks a flickering light while he is at a 45-degree angle. Mohri represents Japan's National Space Development Agency (NASDA).

1992-01-01

391

Video of Miscible Fluid Experiment Conducted on NASA Low Gravity Airplane  

NASA Technical Reports Server (NTRS)

This is a video of dyed water being injected into glycerin in a 2.2 centimeter (cm) diameter test tube. The experiment was conducted on the KC-135 aircraft, a NASA plane that creates microgravity and 2g conditions as it maneuvers through multiple parabolas. The water is less dense and so it rises to the top of the glycerin. The goal of the experiment was to determine if a blob of a miscible fluid would spontaneously become spherical in a microgravity environment.

2003-01-01

392

Comparison of Laboratory and Modeling Results for High Strain Rates in Support of the Source Physics Experiment  

NASA Astrophysics Data System (ADS)

The Source Physics Experiment program, conducted in Climax Stock Granite at the Nevada Test Site, will provide ground truth data to create and improve strong ground motion and seismic S-wave generation and propagation models. Modeling using advanced simulation codes will be performed both a priori and after each experiment; a key component in the predictive capability and ultimate validation of the models is the full understanding of the intervening geology between the source and instrumented bore holes including the geomechanical behavior of the site rock/structural features. Mechanical properties determined via laboratory testing of site rocks leads to the parameterization of constitutive models used in the simulations. The combined finite-discrete element method by Munjiza is an excellent tool to address a wide range of problems involving fracturing and fragmentation of solids and has been applied to many complex rock mechanics problems such as block caving, deep mining techniques, rock blasting, and seismic wave propagation. Since most of the problems involving fracture and fragmentation of solids are three dimensional, an improved 2D/3D FEM/DEM capability has been developed at Los Alamos National Laboratory. In this paper, Split Hopkinson Pressure Bar experiments, performed on the Climax Stock Granite by Sandia National Laboratories, are simulated using this improved 2D/3D FEM/DEM approach, implemented on LANL's MUNROU (Munjiza-Rougier) code and show excellent agreement.

Sussman, A.; Rougier, E.; Broome, S.; Knight, E.; Pfeifle, T.; Schultz-Fellenz, E. S.

2011-12-01

393

Exploring the worth of geophysical data for characterizing three dimensional transport and heterogeneity in laboratory aquifer experiment  

NASA Astrophysics Data System (ADS)

This study evaluates how geophysical data and tracer concentration time series data can be combined effectively to infer hydraulic properties of a laboratory aquifer tank experiment. The tank's dimensions are 73 cm x 71 cm x 70 cm with a 20 cm fine sand cube placed in the center of the tank, within a larger cube of coarser sand. A series of three experiments are conducted within the tank: (1) lateral extent experiments, (2) concentration experiments, and (3) sampling configuration experiments. The set of lateral extent experiments examine how sensitive geophysical data is to the lateral extent of the tracer injection. The concentration experiments examine how sensitive geophysical data is to the level of concentration injected into the tank. Finally, the sample configuration experiments examine how the length of the geophysical sequence affects the balance between data resolution and temporal smearing of geophysical data. The geophysical data is analyzed using both moment analysis of tomograms and the time series data is analyzed using root mean square error (RMSE) and transformed root mean square error (TRMSE) metrics. The metrics are then compared with modeled data to determine the bias between prediction and observation data. In the end, our results show that geophysical data can be used effectively to incorporate hydrological properties, with a few caveats. The primary contribution of this work is to clarify the effect that experimental design decisions for geophysics (location of electrodes, sequence of electrodes, etc.) have on our ability to describe aquifer properties and evaluate tracer transport.

Urban, R. L.; Reed, P. M.; Singha, K.

2011-12-01

394

Radiation, work experience, and cause specific mortality among workers at an energy research laboratory.  

PubMed Central

A retrospective cohort mortality study was conducted among 8375 white male employees who had worked at the Oak Ridge National Laboratory for at least one month between 1943 and 1972. This plant has been the site of energy related research, including uranium and plutonium reactor technology and radioisotope production. Radiation doses, primarily from gamma rays, were generally low; the median cumulative exposure for workers was 0.16 rems. Historical follow up was conducted for the years 1943-77 and ascertainment of vital status was achieved for 92.3% of the cohort. Standardised mortality ratios (SMRs) were computed to contrast the subjects' cause specific mortality experience with that of the United States white male population. The observed number of 966 deaths from all causes was 73% of the number expected. Mortality deficits were also seen for arteriosclerotic heart disease (SMR = 0.75; 344 observed) and all cancers (SMR = 0.78; 194 observed). These results are indicative of the healthy worker effect and the favourable influence on health of the cohort's relatively high socioeconomic status. Non-statistically significant raised SMRs were seen for all leukaemias (SMR = 1.49, 16 observed), cancer of the prostate (SMR = 1.16, 14 observed), and Hodgkin's disease (SMR = 1.10, 5 observed). Internal comparisons of mortality (standardised rate ratios, SRRs) were made between subgroups of the cohort according to radiation dose level and duration of employment in various job categories. No consistent gradients of cause specific mortality were detected for radiation exposure. Leukaemia mortality was highest among workers with greater than or equal to 10 years employment in engineering (SRR = 2.40) and maintenance (SRR = 3.12) jobs. The association of leukaemia with employment in engineering was unexpected; maintenance jobs entail potential exposures to radiation and to a wide range of organic chemicals; metals, and other substances.

Checkoway, H; Mathew, R M; Shy, C M; Watson, J E; Tankersley, W G; Wolf, S H; Smith, J C; Fry, S A

1985-01-01

395

Results from the LDEF/A0076 cascaded variable conductance heatpipe experiment  

NASA Technical Reports Server (NTRS)

The A0076 Variable Conductance Heat Pipe Experiment (CVCHPE) on the Long Duration Exposure Facility (LDEF) demonstrated temperature control better than +/- 0.3 C during fifty days on on-orbit data collection in a widely varying external environment. The experiment used two series connected, dry reservoir variable conductance heat pipes which require no electrical power for operation. The heat pipes used a central artery design with ammonia working fluid and nitrogen control gas. The LDEF was in orbit for almost six years rather than the planned one year mission. Although no additional data were taken during this extended period, post-test data indicated that the set point drifted upward less than 1 C per year. There were significant changes to the appearance of all external thermal control surfaces primarily due to atomic oxygen degradation, and one small anomaly in the electronics. These changes, though, had little effect on the CVCHPE performance.

Grote, Michael G.

1992-01-01

396

Laboratory experiments on high Rayleigh number thermal convection in a rapidly rotating hemispherical shell  

Microsoft Academic Search

We report the results of laboratory experiments on high Rayleigh number thermal convection in a rotating hemispherical shell at Ekman number of Ek=4.7×10?6. We use the combined effect of centrifugal acceleration and laboratory gravity in the lower hemisphere of a spherical shell to simulate the gravity in the Earth's core. Visualization and recording of the pattern and flow, together with

Ikuro Sumita; Peter Olson

2000-01-01

397

Development of a web-based laboratory for control experiments on a coupled tank apparatus  

Microsoft Academic Search

The Internet provides a new environment for developing a variety of applications for educational and research purposes. This paper presents the implementation of a web-based laboratory experiment on a coupled tank apparatus, a multi-input-multi-output (MIMO) system. The web-based laboratory has been developed to serve students and staff in the Department of Electrical Engineering at the National University of Singapore (NUS).

C. C. Ko; Ben M. Chen; Jianping Chen; Yuan Zhuang; Kay Chen Tan

2001-01-01

398

Scaling of material properties for Yucca Mountain: literature review and numerical experiments on saturated hydraulic conductivity  

SciTech Connect

A review of pertinent literature reveals techniques which may be practical for upscaling saturated hydraulic conductivity at Yucca Mountain: geometric mean, spatial averaging, inverse numerical modeling, renormalization, and a perturbation technique. Isotropic realizations of log hydraulic conductivity exhibiting various spatial correlation lengths are scaled from the point values to five discrete scales through these techniques. For the variances in log{sub 10} saturated hydraulic conductivity examined here, geometric mean, numerical inverse and renormalization adequately reproduce point scale fluxes across the modeled domains. Fastest particle velocities and dispersion measured on the point scale are not reproduced by the upscaled fields. Additional numerical experiments examine the utility of power law averaging on a geostatistical realization of a cross-section similar to the cross-sections that will be used in the 1995 groundwater travel time calculations. A literature review on scaling techniques for thermal and mechanical properties is included. 153 refs., 29 figs., 6 tabs.

McKenna, S.A.; Rautman, C.A.

1996-08-01

399

Recirculation System for Geothermal Energy Recovery in Sedimentary Formations: Laboratory Experiments and Numerical Simulations  

NASA Astrophysics Data System (ADS)

Geothermal energy resources are more widespread than previously thought and have the potential for providing a significant amount of sustainable clean energy worldwide. In particular, hot permeable sedimentary formations provide many advantages over traditional geothermal recovery and enhanced geothermal systems in low permeability crystalline formations. These include: (1) eliminating the need for hydraulic fracturing, (2) significant reduction in risk for induced seismicity, (3) reducing the need for surface wastewater disposal, (4) contributing to decreases in greenhouse gases, and (5) potential use for CO2 sequestration. Advances in horizontal drilling, completion, and production technology from the oil and gas industry can now be applied to unlock these geothermal resources. Here, we present experimental results from a laboratory scale circulation system and numerical simulations aimed at quantifying the heat transfer capacity of sedimentary rocks. Our experiments consist of fluid flow through a saturated and pressurized sedimentary disc of 23-cm diameter and 3.8-cm thickness heated along its circumference at a constant temperature. Injection and production ports are 7.6-cm apart in the center of the disc. We used DI de-aired water and mineral oil as working fluids and explored temperatures from 20 to 150 oC and flow rates from 2 to 30 ml/min. We performed experiments on sandstone samples (Castlegate and Kirby) with different porosity, permeability and thermal conductivity to evaluate the effect of hydraulic and thermal properties on the heat transfer capacity of sediments. The producing fluid temperature followed an exponential form with time scale transients between 15 and 45 min. Steady state outflow temperatures varied between 60% and 95% of the set boundary temperature, higher percentages were observed for lower temperatures and flow rates. We used the flow and heat transport simulator TOUGH2 to develop a numerical model of our laboratory setting. Given the remarkable match between our observations and numerical results, we extended our model to explore a wider range of thermal and hydrological parameters beyond the experimental conditions. Our results prove the capability of heat transfer in sedimentary formations for geothermal energy production.) Sandstone sample with two thermally insulating Teflon caps (white discs). In and out arrows indicate the flow direction while the sample is heated along its circumference (heater not shown). B) Example of a 2D temperature distribution during injection. White x shows the location of the flow ports, inlet (left) and outlet (right). Red is the set boundary temperature and blue is the fluid temperature at the inlet.

Elkhoury, J. E.; Detwiler, R. L.; Serajian, V.; Bruno, M. S.

2012-12-01

400

A laboratory experiment on EM backscatter from Farley-Buneman and gradient drift waves  

NASA Technical Reports Server (NTRS)

Results of laboratory experiment on Bragg backscatter of 3-cm microwaves by turbulent waves driven by the Farley-Buneman and gradient drift instabilities are reported. It is noted that the study is the third in a series of laboratory experiments performed to test, under controlled conditions, prevalent ideas on EM scattering by equatorial and high-latitude ionospheric waves and irregularities. It is shown through separate backscattering from fast and slow ion beam modes that a beam of EM radiation actually provides, in backscatter, information on the spectral content of the scattering medium.

Alport, M. J.; Dangelo, N.; Pecseli, H. L.

1981-01-01

401

Development and Operation of a MUMPS Laboratory Information System: A Decade's Experience  

PubMed Central

We describe more than a decade's experience with inhouse development and operation of a clinical laboratory computer system written in the MUMPS programming language for a 1000 bed teaching hospital. The JHLIS is a networked minicomputer system that supports accessioning, instrument monitoring, and result reporting for over 3000 specimens and 30,000 test results daily. Development and operation of the system accounts for 6% of the budget of the laboratories which have had a 70% increase in workload over the past decade. Our experience with purchased MUMPS software maintained and enhanced inhouse suggests an attractive alternative to lengthy inhouse development.

Miller, R. E.; Causey, J. P.; Moore, G. W.; Wilk, G. E.

1988-01-01

402

FEANICS: A Multi-User Facility For Conducting Solid Fuel Combustion Experiments On ISS  

NASA Technical Reports Server (NTRS)

The Destiny Module on the International Space Station (ISS) will soon be home for the Fluids and Combustion Facility's (FCF) Combustion Integrated Rack (CIR), which is being developed at the NASA Glenn Research Center in Cleveland, Ohio. The CIR will be the platform for future microgravity combustion experiments. A multi-user mini-facility called FEANICS (Flow Enclosure Accommodating Novel Investigations in Combustion of Solids) will also be built at NASA Glenn. This mini-facility will be the primary means for conducting solid fuel combustion experiments in the CIR on ISS. The main focus of many of these solid combustion experiments will be to conduct basic and applied scientific investigations in fire-safety to support NASA's Bioastronautics Initiative. The FEANICS project team will work in conjunction with the CIR project team to develop upgradeable and reusable hardware to meet the science requirements of current and future investigators. Currently, there are six experiments that are candidates to use the FEANICS mini-facility. This paper will describe the capabilities of this mini-facility and the type of solid combustion testing and diagnostics that can be performed.

Frate, David T.; Tofil, Todd A.

2001-01-01

403

Spaceflight hardware for conducting plant growth experiments in space: the early years 1960-2000  

NASA Technical Reports Server (NTRS)

The best strategy for supporting long-duration space missions is believed to be bioregenerative life support systems (BLSS). An integral part of a BLSS is a chamber supporting the growth of higher plants that would provide food, water, and atmosphere regeneration for the human crew. Such a chamber will have to be a complete plant growth system, capable of providing lighting, water, and nutrients to plants in microgravity. Other capabilities include temperature, humidity, and atmospheric gas composition controls. Many spaceflight experiments to date have utilized incomplete growth systems (typically having a hydration system but lacking lighting) to study tropic and metabolic changes in germinating seedlings and young plants. American, European, and Russian scientists have also developed a number of small complete plant growth systems for use in spaceflight research. Currently we are entering a new era of experimentation and hardware development as a result of long-term spaceflight opportunities available on the International Space Station. This is already impacting development of plant growth hardware. To take full advantage of these new opportunities and construct innovative systems, we must understand the results of past spaceflight experiments and the basic capabilities of the diverse plant growth systems that were used to conduct these experiments. The objective of this paper is to describe the most influential pieces of plant growth hardware that have been used for the purpose of conducting scientific experiments during the first 40 years of research. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Porterfield, D. M.; Neichitailo, G. S.; Mashinski, A. L.; Musgrave, M. E.

2003-01-01

404

Cool in the kitchen: Radiation, conduction, and the Newton ``hot block'' experiment  

NASA Astrophysics Data System (ADS)

Despite frequent reference to Newton's law of cooling in physics and math books, the paper in which Newton reported this law is quite obscure and rarely cited. We have managed to acquire a copy of this paper and discuss the interesting experiment that Newton did in his kitchen. Surprisingly, the paper contains no procedural details or data of any experiments measuring the rate at which a hot object cools. We have performed our own kitchen experiments to investigate the cooling of (a) the burner of an electric range and (b) a block of Styrofoam. Newton's law provides a poor model for both systems, whose th!!ermal energy loss we can much better understand by examining closely the effects of radiation and conduction.

Silverman, Mark P.; Silverman, Christopher R.

2000-02-01

405

Enhancements in Glovebox Design Resulting from Laboratory-Conducted FIre Tests  

SciTech Connect

The primary mission of the Pit Disassembly and Conversion Facility (PDCF) Project was to disassemble nuclear weapons pits and convert the resulting special nuclear materials to a form suitable for further disposition. Because of the nature of materials involved, the fundamental system which allowed PDCF to perform its mission was a series of integrated and interconnected gloveboxes which provided confinement and containment of the radioactive materials being processed. The high throughput planned for PDCF and the relatively high neutron and gamma radiation levels of the pits required that gloveboxes be shielded to meet worker dose limits. The glovebox shielding material was required to contain high hydrogen concentrations which typically result in these materials being combustible. High combustible loadings created design challenges for the facility fire suppression and ventilation system design. Combustible loading estimates for the PDCF Plutonium (Pu) Processing Building increased significantly due to these shielding requirements. As a result, the estimates of combustible loading substantially exceeded values used to support fire and facility safety analyses. To ensure a valid basis for combustible loading contributed by the glovebox system, the PDCF Project funded a series of fire tests conducted by the Southwest Research Institute on door panels and a representative glovebox containing Water Extended Polyester (WEP) radiological shielding to observe their behavior during a fire event. Improvements to PDCF glovebox designs were implemented based on lessons learned during the fire test. In particular, methods were developed to provide high levels of neutron shielding while maintaining combustible loading in the glovebox shells at low levels. Additionally, the fire test results led to design modifications to mitigate pressure increases observed during the fire test in order to maintain the integrity of the WEP cladding. These changes resulted in significantly reducing the credited combustible loading of the facility. These advances in glovebox design should be considered for application in nuclear facilities within the Department of Energy complex in the future.

Brooks, Kriston P.; Wunderlich, Gregory M.; Mcentire, James R.; Richmond, William G.

2013-06-14

406

Making sense from space-time data in laboratory experiments on space plasma processes  

NASA Technical Reports Server (NTRS)

A number of visualization techniques are discussed in a laboratory experiment designed to study phenomena that occur in space. Visualization tools are used to design the apparatus, collect data, and make one-, two-, and three-dimensional plots of the results. These tools are an indispensable part of the experiment because the data sets are hundreds of megabytes in size and rapid turnaround is required.

Gekelman, Walter; Bamber, James; Leneman, David; Vincena, Steve; Maggs, James; Rosenberg, Steve

1995-01-01

407

Laboratory Experiments on Electrochemical Remediation of the Environment: Electrocoagulation of Oily Wastewater  

NASA Astrophysics Data System (ADS)

A laboratory experiment illustrating the principle and application of electrocoagulation is described using oil-water emulsions as the medium to be treated and iron as the anode. The destabilized oil droplets are shown to be separated from the aqueous phase via electrolysis and iron hydrooxide coagulant formation. This simple experiment is shown to afford opportunities for exploring concepts related to colloid chemistry, electrochemistry, corrosion, and analytical chemistry.

Ibanez, Jorge G.; Takimoto, Martha M.; Vasquez, Ruben C.; Basak, Sanjay; Myung, Noseung; Rajeshwar, Krishnan

1995-11-01

408

Insights From Laboratory Experiments On Simulated Faults With Application To Fracture Evolution In Geothermal Systems  

SciTech Connect

Laboratory experiments provide a wealth of information related to mechanics of fracture initiation, fracture propagation processes, factors influencing fault strength, and spatio-temporal evolution of fracture properties. Much of the existing literature reports on laboratory studies involving a coupling of thermal, hydraulic, mechanical, and/or chemical processes. As these processes operate within subsurface environments exploited for their energy resource, laboratory results provide insights into factors influencing the mechanical and hydraulic properties of geothermal systems. I report on laboratory observations of strength and fluid transport properties during deformation of simulated faults. The results show systematic trends that vary with stress state, deformation rate, thermal conditions, fluid content, and rock composition. When related to geophysical and geologic measurements obtained from engineered geothermal systems (e.g. microseismicity, wellbore studies, tracer analysis), laboratory results provide a means by which the evolving thermal reservoir can be interpreted in terms of physico-chemical processes. For example, estimates of energy release and microearthquake locations from seismic moment tensor analysis can be related to strength variations observed from friction experiments. Such correlations between laboratory and field data allow for better interpretations about the evolving mechanical and fluid transport properties in the geothermal reservoir – ultimately leading to improvements in managing the resource.

Stephen L. Karner, Ph.D

2006-06-01

409

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

NASA Astrophysics Data System (ADS)

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

Ventrice, Carl

2009-04-01

410

Laboratory experiments on stability and entrainment of oceanic stratocumulus. Part 1: Instability experiment  

NASA Technical Reports Server (NTRS)

The existence and persistence of marine stratocumulus play a significant role in the overall energy budget of the earth. Their stability and entrainment process are important in global climate studies, as well as for local weather forecasting. The purposes of the experimental simulations are to study this process and to address this paradox. The effects of buoyancy reversal is investigated, followed by two types of experiments. An instability experiment involves the behavior of a fully turbulent wake near the inversion generated by a sliding plate. Due to buoyancy reversal, the heavy, mixed fluid starts to sink, turning the potential energy created by the mixing process into kinetic energy, thereby increasing the entrainment rate. An entrainment experiment, using a vertically oscillating grid driven by a controllable speed motor, produces many eddy-induced entrainments at a surface region on scales much less than the depth of the layer.

Shy, Shenqyang S.

1990-01-01

411

Experiences of health professionals who conducted root cause analyses after undergoing a safety improvement programme  

PubMed Central

Background Research on root cause analysis (RCA), a pivotal component of many patient safety improvement programmes, is limited. Objective To study a cohort of health professionals who conducted RCAs after completing the NSW Safety Improvement Program (SIP). Hypothesis Participants in RCAs would: (1) differ in demographic profile from non?participants, (2) encounter problems conducting RCAs as a result of insufficient system support, (3) encounter more problems if they had conducted fewer RCAs and (4) have positive attitudes regarding RCA and safety. Design, setting and participants Anonymous questionnaire survey of 252 health professionals, drawn from a larger sample, who attended 2?day SIP courses across New South Wales, Australia. Outcome measures Demographic variables, experiences conducting RCAs, attitudes and safety skills acquired. Results No demographic variables differentiated RCA participants from non?participants. The difficulties experienced while conducting RCAs were lack of time (75.0%), resources (45.0%) and feedback (38.3%), and difficulties with colleagues (44.5%), RCA teams (34.2%), other professions (26.9%) and management (16.7%). Respondents reported benefits from RCAs, including improved patient safety (87.9%) and communication about patient care (79.8%). SIP courses had given participants skills to conduct RCAs (92.8%) and improve their safety practices (79.6%). Benefits from the SIP were thought to justify the investment by New South Wales Health (74.6%) and committing staff resources (72.6%). Most (84.8%) of the participants wanted additional RCA training. Conclusions RCA participants reported improved skills and commitment to safety, but greater support from the workplace and health system are necessary to maintain momentum.

Braithwaite, Jeffrey; Westbrook, Mary T; Mallock, Nadine A; Travaglia, Joanne F

2006-01-01

412

Ring-Closing Metathesis: An Advanced Guided-Inquiry Experiment for the Organic Laboratory  

ERIC Educational Resources Information Center

The design and implementation of an advanced guided-inquiry experiment for the organic laboratory is described. Grubbs's second-generation catalyst is used to effect the ring-closing metathesis of diethyl diallylmalonate. The reaction is carried out under an inert atmosphere at room temperature and monitored by argentic TLC. The crude reaction is…

Schepmann, Hala G.; Mynderse, Michelle

2010-01-01

413

Solubility and Solubility Product Determination of a Sparingly Soluble Salt: A First-Level Laboratory Experiment  

ERIC Educational Resources Information Center

A simple experiment was devised to let students determine the solubility and solubility product, "K"[subscript sp], of calcium sulfate dihydrate in a first-level laboratory. The students experimentally work on an intriguing equilibrium law: the constancy of the product of the ion concentrations of a sparingly soluble salt. The determination of…

Bonomo, Raffaele P.; Tabbi, Giovanni; Vagliasindi, Laura I.

2012-01-01

414

A Laboratory Experience for Students of Differential Equations using RLC Circuits.  

ERIC Educational Resources Information Center

Argues that although differential equations are billed as applied mathematics, there is rarely any hands-on experience incorporated into the course. Presents a laboratory project that requires students to obtain data from a physics lab and use that data to compute the coefficients of the second order differential equation, which mathematically…

Graham, Jeff; Barnes, Julia

1997-01-01

415

Laboratory experiment of particle size effect in X-ray fluorescence: implication to remote XRF results  

Microsoft Academic Search

Laboratory experiments have been performed to show that microscopic roughness in the uppermost layer of planetary surface results in remarkable alteration of intensities and spectral profiles of X-ray fluorescence, especially at large phase angles. In our studies, surface roughness was directly measured by laser microscopy. The measured surface profiles were smoothed and approximated into a single cyclic function of rectangular

T. Okada

2004-01-01

416

An Advanced Undergraduate Chemistry Laboratory Experiment Exploring NIR Spectroscopy and Chemometrics  

ERIC Educational Resources Information Center

An advanced undergraduate chemistry laboratory experiment to study the advantages and hazards of the coupling of NIR spectroscopy and chemometrics is described. The combination is commonly used for analysis and process control of various ingredients used in agriculture, petroleum and food products.

Wanke, Randall; Stauffer, Jennifer

2007-01-01

417

Laboratory experiments on electrostatic ion cyclotron waves in a dusty plasma  

Microsoft Academic Search

Current driven electrostatic ion cyclotron (EIC) waves have been observed in a dusty plasma laboratory experiment. The theoretical prediction that a substantial amount of negatively charged dust makes the plasma more unstable to the EIC instability appears to be borne out by the experimental results.

A. Barkan; N. D'Angelo; R. L. Merlino

1995-01-01

418

The Quartz-Crystal Microbalance in an Undergraduate Laboratory Experiment: Measuring Mass  

ERIC Educational Resources Information Center

The study explains the quartz-crystal microbalance (QCM) technique, which is often used as an undergraduate laboratory experiment for measuring the mass of a system. QCM can be used as a mass sensor only when the measured mass is rigidly attached to the surface.

Tsionsky, Vladimir

2007-01-01

419

A Static Method as an Alternative to Gel Chromatography: An Experiment for the Undergraduate Biochemistry Laboratory  

ERIC Educational Resources Information Center

This article describes a static method as an alternative to gel chromatography, which may be used as an undergraduate laboratory experiment. In this method, a constant mass of Sephadex gel is swollen in a series of protein solutions. UV-vis spectrophotometry is used to find a partition coefficient, KD, that indicates the fraction of the interior…

Burum, Alex D.; Splittgerber, Allan G.

2008-01-01

420

Liquid-Liquid Extraction of Insecticides from Juice: An Analytical Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

A laboratory experiment was developed to target analytical chemistry students and to teach them about insecticides in food, sample extraction, and cleanup. Micro concentrations (sub-microgram/mL levels) of 12 insecticides spiked into apple juice samples are extracted using liquid-liquid extraction and cleaned up using either a primary-secondary…

Radford, Samantha A.; Hunter, Ronald E., Jr.; Barr, Dana Boyd; Ryan, P. Barry

2013-01-01

421

Warm-Core Eddies Studied by Laboratory Experiments and Numerical Modeling  

Microsoft Academic Search

Aspects of the dynamics of warm-core eddies evolving in a deep ocean are investigated using the results of laboratory experiments and numerical simulations. The vortices, produced experimentally in a system brought to solid body rotation by rapidly lifting a bottomless cylinder containing freshwater immersed in a salty ambient fluid, show clearly the presence of inertial oscillations: deepenings and contractions, shoalings

Angelo Rubino; Peter Brandt

2003-01-01

422

Design Experiments and Laboratory Approaches to Learning: Steps toward Collaborative Exchange.  

ERIC Educational Resources Information Center

Explores how the emerging goals, approaches, and methodologies of design experiments might be productively combined with methods of inquiry common in more traditional laboratory science, considering the potential benefits of such a dialectic. Presents three examples of collaboration and describes steps toward productive exchange (identifying…

McCandliss, Bruce D.; Kalchman, Mindy; Bryant, Peter

2003-01-01

423

Bacterial Production of Poly(3-hydroxybutyrate): An Undergraduate Student Laboratory Experiment  

ERIC Educational Resources Information Center

As part of a multidisciplinary course that is cross-listed between five departments, we developed an undergraduate student laboratory experiment for culturing, isolating, and purifying the biopolymer, poly(3-hydroxybutyrate), PHB. This biopolyester accumulates in the cytoplasm of bacterial cells under specific growth conditions, and it has…

Burns, Kristi L.; Oldham, Charlie D.; May, Sheldon W.

2009-01-01

424

Laboratory Modeling of Space experiments on Expulsion of CO2 ions. Application to Global Warming  

Microsoft Academic Search

An approach to expel minority species which can contribute to global warming from the upper atmosphere in the Arctic region by the use of HF electromagnetic waves has been proposed [1]. Laboratory plasma experiments have been designed to model various aspects of this concept - from the acquisiton of negative charges by green house gases such as CO2 to their

A. Y. Wong

2007-01-01

425

An Open Source Power System Virtual Laboratory: The PSAT Case and Experience  

Microsoft Academic Search

This paper describes the authors' experience in the as- sessment of laboratory activities based on an open source software package for power system analysis, namely, Power System Analysis Toolbox (PSAT). PSAT is currently used in several universities for both undergraduate and graduate courses. PSAT has also its own Web forum, which provides support to students and researchers all around the

Federico Milano; Luigi Vanfretti; Juan Carlos Morataya

2008-01-01

426

Addressing complexity in laboratory experiments: the scaling of dilute multiphase flows in magmatic systems  

Microsoft Academic Search

The kinematic and dynamic scaling of dilute multiphase mixtures in magmatic systems is the only guarantee for the geological verisimilitude of laboratory experiments. We present scaling relations that can provide a more complete framework to scale dilute magmatic systems because they explicitly take into account the complexity caused by the feedback between particles (crystal, bubble, or pyroclast) and the continuous

Alain Burgisser; George W. Bergantz; Robert E. Breidenthal

2005-01-01

427

A Student Laboratory Experiment Based on the Vitamin C Clock Reaction  

ERIC Educational Resources Information Center

The Vitamin C Clock Reaction has now been adapted to serve as a student laboratory experiment in the education process of high-school and college-level general chemistry. Despite of imparting valuable knowledge, it also may be hazardous, as the tincture of iodine contains inflammable substances that may cause burning on prolonged exposure.

Vitz, Ed

2007-01-01

428

Preparations for a high gradient inverse free electron laser experiment at Brookhaven national laboratory  

SciTech Connect

Preparations for an inverse free electron laser experiment at Brookhaven National Laboratory's Accelerator Test Facilty are presented. Details of the experimental setup including beam and laser transport optics are first discussed. Next, the driving laser pulse structure is investigated and initial diagnostics are explored and compared to simulations. Finally, planned improvements to the experimental setup are discussed.

Duris, J.; Li, R. K.; Musumeci, P.; Sakai, Y.; Threlkeld, E.; Williams, O.; Fedurin, M.; Kusche, K.; Pogorelsky, I.; Polyanskiy, M.; Yakimenko, V. [UCLA Department of Physics and Astronomy, Los Angeles, CA 90095 (United States); Accelerator Test Facility, Brookhaven National Laboratory, Upton, NY, 11973 (United States)

2012-12-21