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1

The Online Laboratory: Conducting Experiments in a Real Labor Market  

E-print Network

Online labor markets have great potential as platforms for conducting experiments, as they provide immediate access to a large and diverse subject pool and allow researchers to conduct randomized controlled trials. We argue that online experiments can be just as valid---both internally and externally---as laboratory and field experiments, while requiring far less money and time to design and to conduct. In this paper, we first describe the benefits of conducting experiments in online labor markets; we then use one such market to replicate three classic experiments and confirm their results. We confirm that subjects (1) reverse decisions in response to how a decision-problem is framed, (2) have pro-social preferences (value payoffs to others positively), and (3) respond to priming by altering their choices. We also conduct a labor supply field experiment in which we confirm that workers have upward sloping labor supply curves. In addition to reporting these results, we discuss the unique threats to validity in...

Horton, John J; Zeckhauser, Richard J

2010-01-01

2

Portable conduction velocity experiments using earthworms for the college and high school neuroscience teaching laboratory  

PubMed Central

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 velocities that can be easily measured by manipulating electrode placement and the tactile stimulus. Here, we present a portable and robust experimental setup that allows students to perform conduction velocity measurements within a 30-min to 1-h laboratory session. Our improvement over this well-known preparation is the combination of behaviorally relevant tactile stimuli (avoiding electrical stimulation) with the invention of minimal, low-cost, and portable equipment. We tested these experiments during workshops in both a high school and college classroom environment and found positive learning outcomes when we compared pre- and posttests taken by the students. PMID:24585472

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

2014-01-01

3

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

4

Biochar-Induced Changes in Soil Hydraulic Conductivity and Dissolved Nutrient Fluxes Constrained by Laboratory Experiments  

PubMed Central

The addition of charcoal (or biochar) to soil has significant carbon sequestration and agronomic potential, making it important to determine how this potentially large anthropogenic carbon influx will alter ecosystem functions. We used column experiments to quantify how hydrologic and nutrient-retention characteristics of three soil materials differed with biochar amendment. We compared three homogeneous soil materials (sand, organic-rich topsoil, and clay-rich Hapludert) to provide a basic understanding of biochar-soil-water interactions. On average, biochar amendment decreased saturated hydraulic conductivity (K) by 92% in sand and 67% in organic soil, but increased K by 328% in clay-rich soil. The change in K for sand was not predicted by the accompanying physical changes to the soil mixture; the sand-biochar mixture was less dense and more porous than sand without biochar. We propose two hydrologic pathways that are potential drivers for this behavior: one through the interstitial biochar-sand space and a second through pores within the biochar grains themselves. This second pathway adds to the porosity of the soil mixture; however, it likely does not add to the effective soil K due to its tortuosity and smaller pore size. Therefore, the addition of biochar can increase or decrease soil drainage, and suggests that any potential improvement of water delivery to plants is dependent on soil type, biochar amendment rate, and biochar properties. Changes in dissolved carbon (C) and nitrogen (N) fluxes also differed; with biochar increasing the C flux from organic-poor sand, decreasing it from organic-rich soils, and retaining small amounts of soil-derived N. The aromaticity of C lost from sand and clay increased, suggesting lost C was biochar-derived; though the loss accounts for only 0.05% of added biochar-C. Thus, the direction and magnitude of hydraulic, C, and N changes associated with biochar amendments are soil type (composition and particle size) dependent. PMID:25251677

Barnes, Rebecca T.; Gallagher, Morgan E.; Masiello, Caroline A.; Liu, Zuolin; Dugan, Brandon

2014-01-01

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

Recent experiments on the hydrodynamics of laser-produced plasmas conducted at the PALS laboratory  

Microsoft Academic Search

We present a series of experimental results, and their interpretation, connected to various aspects of the hydrodynamics of laser produced plasmas. Experiments were performed using the Prague PALS iodine laser working at 0.44 mm wavelength and irradiances up to a few 1014 W0cm2. By adopting large focal spots and smoothed laser beams, the lateral energy transport and lateral expansion have

D. Batani; R. Dezulian; R. Redaelli; R. Benocci; H. Stabile; F. Canova; T. Desai; G. Lucchini; E. Krousky; K. Masek; M. Pfeifer; J. Skala; R. Dudzak; B. Rus; J. Ullschmied; V. Malka; J. Faure; M. Koenig; J. Limpouch; W. Nazarov; D. Pepler; K. Nagai; T. Norimatsu; H. Nishimura

2007-01-01

7

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.

8

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

9

Thunderstorm charging: Laboratory experiments clarified  

Microsoft Academic Search

Further laboratory experiments of thunderstorm charging by ice crystal collisions with riming graupel pellets have led to results that may help account for a major difference between two independent studies reported earlier. The problem concerns values of the cloud liquid water content required to change the sign of graupel charging. The present work has noted and investigated differences in the

I. M. Brooks; C. P. R. Saunders

1995-01-01

10

Beowulf Cluster Lab Laboratory Experience  

E-print Network

Beowulf Cluster Lab Laboratory Experience The Beowulf Cluster has 61 nodes: the master node is beowulf (also known as node00 inside the cluster), the compute nodes are node01, node02, . . ., node60 parallel programs. A more detailed users guide for the Beowulf Cluster Lab is at: http://cs.boisestate.edu/~amit/research/beowulf

Jain, Amit

11

Soap vs. Sanitizer Laboratory Experiment  

E-print Network

Soap vs. Sanitizer Laboratory Experiment #12;Why wash your hands? Hand are the most frequent with soap and warm water for 20 seconds to 2 minutes. Scrubbing your hands physically removes dirt and viruses. Use enough sanitizer to keep your hands wet while you rub for at least 30 seconds. #12;Soap vs

Rose, Michael R.

12

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...

13

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

14

Thunderstorm charging: Laboratory experiments clarified  

NASA Astrophysics Data System (ADS)

Further laboratory experiments of thunderstorm charging by ice crystal collisions with riming graupel pellets have led to results that may help account for a major difference between two independent studies reported earlier. The problem concerns values of the cloud liquid water content required to change the sign of graupel charging. The present work has noted and investigated differences in the techniques of cloud nucleation used in the two studies. In one set of measurements by Takahashi, ice crystals are nucleated continuously in a supercooled water droplet cloud, while in the other experiments by Jayaratne et al. and Saunders et al., the droplet cloud is nucleated only briefly. These two nucleation methods lead to differences in the mass of cloud particles collected on a sampling probe used to determine the liquid water content of the cloud. In the continuous nucleation case, the probe collects sufficient numbers of ice crystals to lead to a substantial overestimate of the cloud liquid water content.

Brooks, I. M.; Saunders, C. P. R.

15

Particle transport in unsaturated fractured chalk under arid A series of field and laboratory experiments were conducted to study the mechanisms of particle  

E-print Network

Particle transport in unsaturated fractured chalk under arid conditions Abstract A series of field fractures in vadose chalk. Experiments of intermittent flow events along fracture surfaces were carried out

Weisbrod, Noam

16

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

17

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

18

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

19

Critical experiments at Pacific Northwest Laboratory  

Microsoft Academic Search

Critical experiment programs at the Critical Mass Laboratory (CML) of the Pacific Northwest Laboratory (PNL) are discussed and projected requirements for critical experiment data in different areas of the fuel recycle; processing, fabrication, storage and shipment are reviewed. Recent experiments at the CML include: Criticality Measurements on (1) homogeneous aqueous solutions of Pu and U (up to 60 wt% Pu),

E. D. Clayton; S. R. Bierman

1983-01-01

20

Data on conducting the SAMEX-76 experiment  

NASA Technical Reports Server (NTRS)

The compilation of data on conducting the SAMEX-76 experiment is reported. This report includes many tables and graphs of the aircraft's flights and its measurements. Also given is the operation time of this equipment and the many observations that have been made by the Scientific Research Ship Akademik Korolev.

1978-01-01

21

Suspended sediment erosion in laboratory flume experiments  

E-print Network

Laboratory flume experiments are used to examine the role of suspended sediment abrasion in bedrock channel erosion. A range of topographies was used, from a planar bed to a sinuous and scalloped inner channel. Experiments ...

Cornell, Katrina Muir

2007-01-01

22

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

23

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

24

Oak Ridge National Laboratory's Values in the Conduct of  

E-print Network

#12;Oak Ridge National Laboratory's Values in the Conduct of Research and Development Prepared by the ORNL Corporate Fellows Council Distributed by the ORNL Ethics Office January 2000 i Managed by OAK RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee 37831-6285 operated by LOCKHEED MARTIN ENERGY RESEARCH

25

Multidimensional Screening as a Pharmacology Laboratory Experience.  

ERIC Educational Resources Information Center

A multidimensional pharmacodynamic screening experiment that addresses drug interaction is included in the pharmacology-toxicology laboratory experience of pharmacy students at the University of the Pacific. The student handout with directions for the procedure is reproduced, drug compounds tested are listed, and laboratory evaluation results are…

Malone, Marvin H.; And Others

1979-01-01

26

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...

27

Practical Enzyme Kinetics: A Biochemical Laboratory Experiment.  

ERIC Educational Resources Information Center

Describes an experiment that provides a fundamental understanding of the kinetics of the enzyme papain. Discusses background, materials, procedures and results. Mentions analogous experiments that can be conducted with enzymatic contact-lens cleaning solutions. (CW)

Rowe, H. Alan; Brown, Morris

1988-01-01

28

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

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

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

31

Virtual geotechnical laboratory experiments using a simulator  

Microsoft Academic Search

The details of a test simulator that provides a realistic environment for performing virtual laboratory experimentals in soil mechanics is presented. A computer program Geo-Sim that can be used to perform virtual experiments, and allow for real-time observations of material response is presented. The results of experiments, for a given set of input parameters, are obtained with the test simulator

Dayakar Penumadu; Rongda Zhao; David Frost

2000-01-01

32

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

33

Laboratory-based conductivity structure in the mantle transition zone  

NASA Astrophysics Data System (ADS)

Recent laboratory electrical conductivity measurements of the main mantle constituent minerals have refined our understanding of the effect of water and iron content on electrical conductivity. However, there have remained inconsistency of conductivity data between different laboratories, especially effect of water on the conductivity (proton conduction). Karato and Dai (2009) claimed that our group’s data, mostly based on low frequency measurements, used incorrect sample conductivity values, because their impedance spectroscopy for wet wadsleyite measured at high temperatures showed an additional tail at low frequencies. To calrify a cause of this discrepancy, we performed the impedance spectroscopic measurements for wadsleyite in a wide frequency range at low temperatures (< 1000 K) to minimize dehydration of samples. The results are quite consisitent with ours measured at low frequencies, and did not show a large contribution of small amount of water to the conductivity and an additional tail at low frequencies due to the electrode reaction. It is concluded that the conductivity measurement at high temperatures (> 1000 K) leads to higher conductivity due to the grain boundary water generated by dehydration of sample. Next we consider the electrical conductivity structure of the mantle transition zone based on our results. The electrical conductivity of the Earth’s mantle is controlled by the coexistence of multiple mineral phases. Using these conductivity data of mantle minerals and geotherm models, the laboratory-based conductivity-depth profiles have been constructed of a 200 to 800 km depth range across the mantle transition zone. These profiles are based on mixing models of composite materials, which assume a pyrolitic composition, and they are a function of water content in main constituent minerals. The calculated conductivity values increase from 0.01 S/m at 200 km depth to 100 S/m at 800 km depth. Considering the conductivity change due to the phase change only, our model predicts similar values between olivine and wadsleyite, but they differ up to nearly one order of magnitude between wadesleyite and ringwoodite. In other words, if a conductivity jump accompanies the 410 km seismic discontinuity, it will not be due to the phase change but to a secondary effect, such as difference in water content. Instead, a notable conductivity jump appears at a depth of 520 km in the wadsleyite-ringwoodite transition with or without water. The present conductivity-depth profile in the transition zone agrees with that obtained from the geophysical observations beneath the Pacific Ocean in the case of the dry mantle transition zone. The absolute conductivity values obtained from the conductivity profiles beneath the Philippine Sea, where stagnant slab exists, are too high to be explained by the dry pyrolite model, especially in the stability field of wadsleyite. Presence of water in the transition zone minerals is required to explain such high conductivity.

Yoshino, T.; Katsura, T.; Shimojuku, A.

2010-12-01

34

Making Sparklers: An Introductory Laboratory Experiment  

NASA Astrophysics Data System (ADS)

A laboratory experiment consisting of the preparation of sparklers has been developed as part of a project which organizes the general chemistry sequence according to subjects with which students are familiar. This laboratory makes use of oxidation/reduction chemistry to produce a product familiar to students. The result is a mixture rather than a compound, but the composition must be carefully measured to produce a sparkler that will stay lit and produce sparks. The dramatic reaction may be the most impressive and memorable experience that students encounter in the laboratory. Sparklers are formulated from iron, magnesium, and aluminum powders, plus potassium chlorate and barium nitrate held on thick iron wire by a starch paste. At elevated temperatures metal nitrates and chlorates decompose to produces gases, providing the necessary force to eject bits of powdered, burning metal into the air.

Keeney, Allen; Walters, Christina; Cornelius, Richard D.

1995-07-01

35

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.

36

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

37

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

38

Computer Based Simulation of Laboratory Experiments.  

ERIC Educational Resources Information Center

Examines computer based simulations of practical laboratory experiments in engineering. Discusses the aims and achievements of lab work (cognitive, process, psychomotor, and affective); types of simulations (model building and behavioral); and the strengths and weaknesses of simulations. Describes the development of a centrifugal pump simulation,…

Edward, Norrie S.

1997-01-01

39

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

40

SOME EXPERIMENTS ON ELECTRICAL CONDUCTION IN VACUUM  

Microsoft Academic Search

The conduction of electricity through a vacuum was investigated in high ; voltage generators using beta emitters as current sources, The voltage attained ; by the generators was limited by vacuum conduction to values of tens to a few ; hundreds of kilovolts. The leakage current responsible for this limitation in ; most cases was found to consist of an

J. W. Kennedy; E. A. Bryant; U. Merten; P. V. Murphy; E. K. Storms

1957-01-01

41

Radionuclide migration: laboratory experiments with isolated fractures  

SciTech Connect

Laboratory experiments examining flow and element migration in rocks containing isolated fractures have been initiated at the Los Alamos National Laboratory. Techniques are being developed to establish simple fracture flow systems which are appropriate to models using analytical solutions to the matrix diffusion-flow equations, such as those of I. Neretnieks [I. Neretnieks, Diffusion in the Rock Matrix: An Important Factor in Radionuclide Retardation? J. Geophys. Res. 85, 4379 (1980).] These experiments are intended to be intermediate steps toward larger scale field experiments where it may become more difficult to establish and control the parameters important to nuclide migration in fractured media. Laboratory experiments have been run on fractures ranging in size from 1 to 20 cm in length. The hydraulic flow in these fractures was studied to provide the effective apertures. The flows established in these fracture systems are similar to those in the granite fracture flow experiments of Witherspoon et al. [P.A. Witherspoon, J.S.Y. Wang, K. Iwai, and J.E. Gale, Validity of Cubic Law for Fluid Flow in a Deformable Rock Fracture, Lawrence Berkeley Laboratory report LBL-9557 (October 1979).] Traced solutions containing {sup 85}Sr and {sup 137}Cs were flowed through fractures in Climax Stock granite and welded tuff (Bullfrog and Tram members, Yucca Mountain, Nevada Test Site). The results of the elutions through granite agree with the matrix diffusion calculations based on independent measurements of K/sub d/. The results of the elutions through tuff, however, agree only if the K/sub d/ values used in the calculations are lower than the K/sub d/ values measured using a batch technique. This trend has been previously observed in chromatographic column experiments with tuff. 5 figures, 3 tables.

Rundberg, R.S.; Thompson, J.L.; Maestas, S.

1982-12-31

42

Generating Reproducible Heterogeneity for Laboratory Flow and Transport Experiments  

NASA Astrophysics Data System (ADS)

To understand the impact of heterogeneity on unsaturated flow and transport processes, many researchers have begun to conduct flow and transport experiments in laboratory analogues to heterogeneous geologic materials. Most of these experiments are conducted in macroheterogeneous media where homogeneous units are arranged to represent large-scale heterogeneity. However, most sedimentary media displays heterogeneity at a hierarchy of scales, the smallest of which is a stratum that is graded. Such stratification can lead to complicated wetted-phase structures that influence moisture retention, unsaturated hydraulic conductivity, access to surface area for reaction, and non-ideal transport. Because of the difficulty in reproducing "geologically realistic" microheterogeneity, the impact of small-scale stratification on flow and transport is difficult to evaluate using current laboratory constructed analogues. We have developed and evaluated a new approach for constructing reproducible, "geologically realistic" heterogeneity for laboratory flow and transport experiments. Using an apparatus with a computer-controlled arm, mixtures of sand are deposited in an experimental chamber through a tube. Mechanical grading processes within the tube and the chamber lead to stratification that mimics that produced by sedimentary processes. By varying the arm speed, stratum thickness and angle can be controlled. By using different sand mixtures, the grain size at the top and bottom of a stratum can be varied. Through the use of carefully designed computer programs, a variety of reproducible micro/macroheterogeneous structures can be produced.

Griffith, B. C.; Holt, R. M.; Glass, R. J.

2003-12-01

43

Progress photograph of sample experiments being conducted with lunar material  

NASA Technical Reports Server (NTRS)

A progress photograph of sample experiments being conducted in the Manned Spacecraft Center's Lunar Receiving Laboratory with lunar material brought back to Earth by the crew of the Apollo 11 mission. Aseptic cultures of liverwort (marchantia polymorpha) - a species of plant commonly found growing on rocks or in wooded areas - are shown in two rows of sample containers. Seven weeks or some 50 days prior to this photograph 0.22 grams of finely ground lunar material was added to each of the upper samples of cultures. The lower cultures were untreated, and a noted difference can be seen in the upper row and the lower one, both in color and size of the culture.

1969-01-01

44

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

45

A Guide for Conducting Outdoor Field Experiences.  

ERIC Educational Resources Information Center

Since research indicates teachers generally lack confidence in their ability to conduct lessons in the outdoors and feel inadequate regarding knowledge of the natural world, this guide has been developed to build teacher confidence in utilizing the outdoors. Designed to be used in conjunction with a practicum workshop, this guide presents…

Matthews, Bruce; And Others

46

Research and the planned Space Experiment Research and Processing Laboratory  

NASA Technical Reports Server (NTRS)

Original photo and caption dated June 22, 1988: 'A dwarf wheat variety known as Yecoro Rojo flourishes in KSC's Biomass Production Chamber. Researchers are gathering information on the crop's ability to produce food, water and oxygen, and then remove carbon dioxide. The confined quarters associated with space travel require researchers to focus on smaller plants that yield proportionately large amounts of biomass. This wheat crop takes about 85 days to grow before harvest.' Plant experiments such as this are 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

47

Systems integration test laboratory application & experiences  

NASA Astrophysics Data System (ADS)

The ability to safely control highly dynamic systems is of prime importance to designers. Whether the system is an aircraft, spacecraft, or propulsion system, control system designers must turn to test laboratories not only to verify and validate the control systems, but also to actually use the laboratory as a design and development tool. The use of the laboratory early in the development phase of a system—prior to committing to actual hardware/software (HW/SW)—permits early detection of system anomalies, thereby minimizing program development costs while enhancing safety. Later the laboratory can be used to train system operators (for example, pilots, ground crew) in preparation for flight/ground test. In the case of the statically unstable X-29 forward swept wing aircraft, a comprehensive real-time, hardware-in-the-loop test facility was critical in the development of the aircraft's digital fly-by-wire (FBW) flight control system. The X-29 laboratory initially was used to introduce control laws to a simulated real-time environment to verify control system characteristics. Later, actual flight hardware was introduced to the laboratory, at which point the formal system verification/validation test program began. The test program utilized detailed test plans and procedures derived from system requirements and specifications to map out all tests required. This assured that the maximum number of components of the system were exercised in the laboratory, and all components tested had traceability throughout the test program. The end-to-end hardware-in-the loop simulation provided the environment to perform critical failure modes testing, parameter sensitivity evaluation and ultimately pilot/ground crew training during normal and degraded flight control system operation. The X-29 test experience, applicable to the laboratory testing of all critical control systems, has ingrained the philosophy that successful development of complex systems requires an orderly build-up of complexity within the laboratory. By this we mean that components of the simulation are introduced to the laboratory only when previous additions are well understood and formally verified by prescribed testing procedures. First, non-real-time computer models of the system are developed (for example, stability derivatives from scale model wind tunnel data). Upon reaching a level of maturity, these non-real-time codes are implemented and verified in a real-time environment. The real-time implementation is important because it lends itself to interfacing with actual flight hardware and software for final verification/validation (V/V) and training. This philosophy of laboratory management for critical control systems test is not limited to aircraft applications. Any dynamic control system could be developed and tested in a fashion similar to the X-29 control system. The gradual buildup of complexity in the laboratory commencing with non-real-time math modeling, leading to real-time, hard-ware-in-the-loop validation and ultimately operator training is a necessary procedure for obtaining safe, reliable systems. This paper discusses the experience gained from the development of the X-29 digital flight control system, use of the laboratory for development, verification and validation, and how this test philosophy is applied to any system.

Rimer, Melvyn; Falco, Michael; Solan, Michael J.

1991-01-01

48

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

49

Psychiatric Residents' Experience Conducting Disability Evaluations  

ERIC Educational Resources Information Center

Objective: The increasing frequency and societal cost of psychiatric disability underscore the need for accuracy in evaluating patients who seek disability benefits. The authors investigated senior psychiatric residents' experiences performing disability evaluations, their self-assessment of competence for this task, and whether they perceived a…

Christopher, Paul P.; Boland, Robert J.; Recupero, Patricia R.; Phillips, Katharine A.

2010-01-01

50

Payload specialists Patrick Baudry conducts equilibrium experiments  

NASA Technical Reports Server (NTRS)

Payload specialists Patrick Baudry participates in an experiment involving equilibrium and vertigo. He is anchored to the orbiter floor by foot restraints and is wearing a device over his eyes to measure angular head movement and up and down eye movement.

1985-01-01

51

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

52

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

53

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

54

Weld Tests Conducted by the Idaho National Laboratory  

SciTech Connect

During the fiscal year of 2006, the Idaho National Laboratory (INL) performed many tests and work relating to the Mobile Melt-Dilute (MMD) Project components. Tests performed on the Staubli quick disconnect fittings showed promising results, but more tests were needed validate the fittings. Changes were made to the shield plug design—reduced the closure groove weld depth between the top of the canister and the top plate of the shielding plug from 0.5-in to 0.375-in deep. Other changes include a cap to cover the fitting, lifting pintle and welding code citations on the prints. Tests conducted showed stainless steel tubing, with 0.25-in, 0.375-in, and 0.5-in diameters, all with 0.035-in wall thickness, could be pinch seal welded using commercially available resistance welding equipment. Subsequent testing showed that these welds could be real-time inspected with ultrasonic inspection methods.

Larry Zirker; Lance Lauerhass; James Dowalo

2007-02-01

55

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

56

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

57

21 CFR 58.130 - Conduct of a nonclinical laboratory study.  

Code of Federal Regulations, 2010 CFR

...FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory...be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall...

2010-04-01

58

21 CFR 58.130 - Conduct of a nonclinical laboratory study.  

Code of Federal Regulations, 2011 CFR

...FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory...be conducted in accordance with the protocol. (b) The test systems shall be monitored in conformity with the protocol. (c) Specimens shall...

2011-04-01

59

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

60

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

61

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

62

Elucidating GPR Response to Biological Activity: Field and Laboratory Experiments  

NASA Astrophysics Data System (ADS)

Recent studies of the geophysical signatures of biological processes in earth environments have resulted in the emergent field of “biogeophysics”. The ability to monitor remotely and to quantify active biological processes in the subsurface can have transformative implications to a wide range of investigations, including the bioremediation of contaminated sites. Previous studies have demonstrated that ground-penetrating radar (GPR) can be used to detect the products of microbial activity in the subsurface, such as changes in bulk electrical conductivity, mineral dissolution and precipitation, and the formation of biogenic gas. We present field and laboratory experiments that offer insights to the response of GPR signals to microbial activity. In the field, time-lapse borehole radar tomography was used to monitor biodegradation of a hydrocarbon plume over a period of two years. A dense grid of fourteen borehole pairs monitoring the bioactive region showed radar wave velocity changes of +/-4% and signal attenuation changes of +/-25%. These GPR observations correlated spatially and temporally to independent measurements of groundwater velocity and geochemical variations that occurred in response to microbial activity. The greatest relative changes in radar wave velocity of propagation and attenuation were observed in the region of enhanced bacterial stimulation where biomass growth was the greatest. Radar wave velocity and attenuation decreased during periods of enhanced biostimulation. Two laboratory experiments were conducted to further assess radar response to biomass growth. The first experiment monitored GPR wave transmission through a water-saturated quartz-sand reactor during the course of enhanced biostimulation. Radar wave velocity initially decreased as a result of bacterial activity and subsequently increased rapidly as biogenic gas formed in the pore space. Radar signal attenuation increased during the course of the experiment as a result of an increase in pore fluid electrical conductivity. The second experiment examined GPR wave transmission through incrementally increasing concentrations of Shewanella putrefaciens strain 200R in a fluid suspension. Recorded GPR waveforms exhibited dispersion as the concentration of suspended cells increased. The radar wave velocity decrease observed in the field and laboratory measurements provide direct evidence of saturated sand bulk dielectric constant increase when biomass forms in the pore space, suggesting biomass dielectric constant being greater than that of pore water. The decrease in radar signal attenuation observed in the field during enhanced biodegradation is in contrast to high GPR attenuation observed in mature hydrocarbon contaminated sites where high conductivity pore fluids do not allow direct assessment of biomass effect on GPR signal attenuation. We conclude that field and laboratory GPR observations of enhanced biological activity in saturated porous media and in fluid suspension offer evidence that GPR can be used to monitor biostimulation in earth environments.

Tsoflias, G. P.; Schillig, P. C.; McGlashan, M. A.; Roberts, J. A.; Devlin, J. F.

2010-12-01

63

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...

64

Experiment definition phase shuttle laboratory. LDRL-10.6 experiment  

NASA Technical Reports Server (NTRS)

The work completed on the experiment definition phase of the shuttle laboratory LDRL 10.6 micrometers experiment from 27 September 1975 to 26 January 1976 was reported. This work included progress in the following areas: (1) optomechanical system: completion of detail drawings, completion of the beryllium subassembly, fabrication, checking, and weighing of approximately 95% of the detailed parts, dry film lubrication of the bearings and gears, and initiation of assembly of the gimbals; (2) optics: update of the detailed optical layout, receipt of nine mirrors and the pre-expander; (3) miscellaneous: delivery of draft material for the final report, completion of optical testing of the 10.6 micrometers receiver, and receipt, assembly, and checkout of NASA test console.

1976-01-01

65

Laboratory experiments of tsunami runup on a circular island  

Microsoft Academic Search

Laboratory experiments of a 7.2-m-diameter conical island were conducted to study three-dimensional tsunami runup. The 62.5-cm tall island had 1 on 4 side slopes and was positioned in the center of a 30-m-wide by 25-m-long flat-bottom basin. Solitary waves with height-to-depth ratios ranging from 0.05 to 0.20 and “source” lengths ranging from 0.30 to 7.14 island diameters were tested in

Michael J. Briggs; Costas E. Synolakis; Gordon S. Harkins; Debra R. Green

1995-01-01

66

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

67

Laboratory derived constraints on electrical conductivity beneath Slave craton  

NASA Astrophysics Data System (ADS)

The depth profile of the electrical conductivity, ?(d), beneath the Central Slave craton (Canada) has been reconstructed with the help of laboratory measurements carried out on peridotite xenoliths. ?(T) of xenoliths was determined in the piston-cylinder apparatus at 1 and 2 GPa and from 600 to 1150 °C. ?(T) of xenoliths follows the Arrhenius dependence with the activation energy, E, varying from 2.10 to 1.44 eV depending on temperature range and the Mg-number. The calculated xenolith geotherm and the suggested lithology beneath the Central Slave have been used to constrain ?(d) as follows: ?(d) in the crust varies between 0.5×10-5 and 10-3 S/m; the lithospheric ?(d) sharply decreases below the Moho at 39.4 km to 0.5×10-8 S/m, which corresponds to 460 °C, and then gradually increases with the depth d to 0.5×10-2 S/m. The modeled MT-response of the constrained ?(d) profile has been compared with MT-observations [Jones, A.G., Lezaeta, P., Ferguson, I.J., Chave, A.D., Evans, R.L., Garcia, X., Spratt J., 2003. The electrical structure of the Slave craton. Lithos, 71, 505-527]. The general trend of the calculated MT-response based on the ?(d) model mimics the MT-inversion of the field data from the Central Slave.

Bagdassarov, Nikolai S.; Kopylova, Maya G.; Eichert, Sandrine

2007-04-01

68

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

69

Laboratory measurements of electrical conductivities of hydrous and dry Mount Vesuvius melts under pressure  

NASA Astrophysics Data System (ADS)

Quantitative interpretation of MT anomalies in volcanic regions requires laboratory measurements of electrical conductivities of natural magma compositions. The electrical conductivities of three lava compositions from Mount Vesuvius (Italy) have been measured using an impedance spectrometer. Experiments were conducted on both glasses and melts between 400 and 1300°C, at both ambient pressure in air and high pressures (up to 400 MPa). Both dry and hydrous (up to 5.6 wt % H2O) melt compositions were investigated. A change of the conduction mechanism corresponding to the glass transition was systematically observed. The conductivity data were fitted by sample-specific Arrhenius laws on either side of Tg. The electrical conductivity increases with temperature and is higher in the order tephrite, phonotephrite to phonolite. For the three investigated compositions, increasing pressure decreases the conductivity, although the effect of pressure is relatively small. The three investigated compositions have similar activation volumes (?V = 16-24 cm3 mol-1). Increasing the water content of the melt increases the conductivity. Comparison of activation energies (Ea) from conductivity and sodium diffusion and use of the Nernst-Einstein relation allow sodium to be identified as the main charge carrier in our melts and presumably also in the corresponding glasses. Our data and those of previous studies highlight the correlation between the Arrhenius parameters Ea and ?0. A semiempirical method allowing the determination of the electrical conductivity of natural magmatic liquids is proposed, in which the activation energy is modeled on the basis of the Anderson-Stuart model, ?0 being obtained from the compensation law and ?V being fitted from our experimental data. The model enables the electrical conductivity to be calculated for the entire range of melt compositions at Mount Vesuvius and also satisfactorily predicts the electrical response of other melt compositions. Electrical conductivity data for Mount Vesuvius melts and magmas are slightly lower than the electrical anomaly revealed by MT studies.

Pommier, A.; Gaillard, F.; Pichavant, M.; Scaillet, B.

2008-05-01

70

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

71

Magnetized laboratory plasma jets: Experiment and simulation.  

PubMed

Experiments involving radial foils on a 1 MA, 100 ns current driver can be used to study the ablation of thin foils and liners, produce extreme conditions relevant to laboratory astrophysics, and aid in computational code validation. This research focuses on the initial ablation phase of a 20 ?m Al foil (8111 alloy), in a radial configuration, driven by Cornell University's COBRA pulsed power generator. In these experiments ablated surface plasma (ASP) on the top side of the foil and a strongly collimated axial plasma jet are observed developing midway through the current rise. With experimental and computational results this work gives a detailed description of the role of the ASP in the formation of the plasma jet with and without an applied axial magnetic field. This ?1 T field is applied by a Helmholtz-coil pair driven by a slow, 150 ?s current pulse and penetrates the load hardware before arrival of the COBRA pulse. Several effects of the applied magnetic field are observed: (1) without the field extreme-ultraviolet emission from the ASP shows considerable azimuthal asymmetry while with the field the ASP develops azimuthal motion that reduces this asymmetry, (2) this azimuthal motion slows the development of the jet when the field is applied, and (3) with the magnetic field the jet becomes less collimated and has a density minimum (hollowing) on the axis. PERSEUS, an XMHD code, has qualitatively and quantitatively reproduced all these experimental observations. The differences between this XMHD and an MHD code without a Hall current and inertial effects are discussed. In addition the PERSEUS results describe effects we were not able to resolve experimentally and suggest a line of future experiments with better diagnostics. PMID:25679726

Schrafel, Peter; Bell, Kate; Greenly, John; Seyler, Charles; Kusse, Bruce

2015-01-01

72

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

73

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 harvests a potato grown in the Biomass Production Chamber of the Controlled environment 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.' His 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

74

Laboratory-Measured and Property-Transfer Modeled Saturated Hydraulic Conductivity of Snake River Plain  

E-print Network

Plain Aquifer Sediments at the Idaho National Laboratory, Idaho Scientific Investigations Report 2008 Conductivity of Snake River Plain Aquifer Sediments at the Idaho National Laboratory, Idaho By Kim S. Perkins saturated hydraulic conductivity of Snake River Plain aquifer sediments at the Idaho National Laboratory

75

Laboratory experiments on nonlinear Electron MHD phenomena  

NASA Astrophysics Data System (ADS)

In a large laboratory plasma highly nonlinear magnetic field-plasma interactions are studied in the regime of Electron MHD (EMHD). A pulsed magnetic field is applied with a loop antenna and the resultant field is measured with magnetic probes. Topologies of field-reversed configurations (FRC), spheromaks or strong mirrors are generated. These fields propagate as highly nonlinear whistler modes through the stationary ion background. Whistler spheromaks propagate along the ambient magnetic field at a speed which decreases with amplitude. The field tilts (precesses) with increasing amplitude. The field at the leading front steepens to a few c/?pe, i.e. forms a whistler shock. The electrons in the (predominantly) toroidal current ring are heated and produce visible light. The source of heating is not significantly modified by heat conduction and radiation losses. The collision of two counter-propagating whistler spheromaks leads to a whistler FRC with net zero helicity. Whistler mirrors are produced when the wave field adds to the ambient field. These structures propagate faster than spheromaks and linear whistlers. The toroidal current is predominantly an electron Hall current which produces no electron heating. Collisions between opposing whistler mirrors produces no significant electron heating by Fermi acceleration. Field topologies lacking axial symmetry, as in strong whistler turbulence, may be characterized by a mixture of magnetic energy convection and dissipation.

Stenzel, Reiner

2006-04-01

76

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 ...

77

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

78

Laboratory Experiment of Checkerboard Pupil Mask Coronagraph  

E-print Network

We present the results of the first laboratory experiment of checkerboard shaped pupil binary mask coronagraphs using visible light, in the context of the R&D activities for future mid-infrared space missions such as the 3.5 m SPICA telescope. The primary aim of this work is to demonstrate the coronagraphic performance of checkerboard masks down to a $10^{-6}$ peak-to-peak contrast, which is required to detect self-luminous extra-solar planets in the mid-infrared region. Two masks, consisting of aluminum films on a glass substrates, were manufactured using nano-fabrication techniques with electron beam lithography: one mask was optimized for a pupil with a 30% central obstruction and the other was for a pupil without obstruction. The theoretical contrast for both masks was $10^{-7}$ and no adaptive optics system was employed. For both masks, the observed point spread functions were quite consistent with the theoretical ones. The average contrast measured within the dark regions was $2.7 {\\times} 10^{-7}$ and $1.1 {\\times} 10^{-7}$. The coronagraphic performance significantly outperformed the $10^{-6}$ requirement and almost reached the theoretical limit determined by the mask designs. We discuss the potential application of checkerboard masks for mid-infrared coronagraphy, and conclude that binary masks are promising for future high-contrast space telescopes.

K. Enya; S. Tanaka; L. Abe; T. Nakagawa

2006-09-23

79

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

80

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

81

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

82

Experiences Using Tablet PCs in a Programming Laboratory  

E-print Network

Experiences Using Tablet PCs in a Programming Laboratory Stephen H. Edwards and N. Dwight Barnette first gen- eration tablet PCs to support active learning in an undergraduate computer science laboratory course. We learned that tablet PCs are poorly matched to typical CS laboratory tasks: writing, com

Edwards, Stephen H.

83

Access to an instructional control laboratory experiment through the World Wide Web  

Microsoft Academic Search

The software for “second best to being there”, a distance learning application that allows a remotely-located user to conduct experiments in the Control Engineering Laboratory at Oregon State University, has been redesigned and implemented in the JavaTM programming language. This permits the experiments to be run via the World Wide Web. Access requires only a basic Web browser that runs

A. Bhandari; M. H. Shor

1998-01-01

84

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

85

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

86

VARIABILITY IN MIXING EFFICIENCY AND LABORATORY ANALYSES OF A COMMON DIET MIXED AT 25 EXPERIMENT STATIONS  

Technology Transfer Automated Retrieval System (TEKTRAN)

An experiment involving 25 experiment stations in the North Central and Southern regions (NCR-42 and S-288, respectively) was conducted to assess the degree of uniformity of diet mixing among stations and to assess the variability among station laboratories in chemical analysis of mixed diets. A fo...

87

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. PMID:24006389

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

2013-01-01

88

LABORATORY EXPERIMENTS AND PROJECTS FOR TEACHING MECHATRONICS TO MECHANICAL ENGINEERS  

Microsoft Academic Search

This paper describes the set of courses and laboratory experiments that have been employed by the authors to teach mechatronics courses at the Universite de Sherbrooke. Authors present how both the laboratory experiments and Internet play an important role in supporting student learning. Copyright c ? 2000 IFAC

Philippe Micheau; Patrice Masson

89

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

90

Macromolecular crystal growth experiments on International Microgravity Laboratory--1.  

PubMed Central

Macromolecular crystal growth experiments, using satellite tobacco mosaic virus (STMV) and canavalin from jack beans as samples, were conducted on a US Space Shuttle mission designated International Microgravity Laboratory--1 (IML-1), flown January 22-29, 1992. Parallel experiments using identical samples were carried out in both a vapor diffusion-based device (PCG) and a liquid-liquid diffusion-based instrument (CRYOSTAT). The experiments in each device were run at 20-22 degrees C and at colder temperatures. Crystals were grown in virtually every trial, but the characteristics of the crystals were highly dependent on the crystallization technique employed and the temperature experience of the sample. In general, very good results, based on visual inspection of the crystals, were obtained in both PCG and CRYOSTAT. Unusually impressive results were, however, achieved for STMV in the CRYOSTAT instrument. STMV crystals grown in microgravity by liquid-liquid diffusion were more than 10-fold greater in total volume than any STMV crystals previously grown in the laboratory. X-ray diffraction data collected from eight STMV crystals grown in CRYOSTAT demonstrated a substantial improvement in diffraction quality over the entire resolution range when compared to data from crystals grown on Earth. In addition, the extent of the diffraction pattern for the STMV crystals grown in space extended to 1.8 A resolution, whereas the best crystals that were ever grown under conditions of Earth's gravity produced data limited to 2.3 A resolution. Other observations indicate that the growth of macromolecular crystals is indeed influenced by the presence or absence of gravity. These observations further suggest, consistent with earlier results, that the elimination of gravity provides a more favorable environment for such processes. PMID:1303744

Day, J.; McPherson, A.

1992-01-01

91

Brownian Motion--a Laboratory Experiment.  

ERIC Educational Resources Information Center

Introduces an experiment involving the observation of Brownian motion for college students. Describes the apparatus, experimental procedures, data analysis and results, and error analysis. Lists experimental techniques used in the experiment. Provides a circuit diagram, typical data, and graphs. (YP)

Kruglak, Haym

1988-01-01

92

Conducting real-time multiplayer experiments on the web.  

PubMed

Group behavior experiments require potentially large numbers of participants to interact in real time with perfect information about one another. In this paper, we address the methodological challenge of developing and conducting such experiments on the web, thereby broadening access to online labor markets as well as allowing for participation through mobile devices. In particular, we combine a set of recent web development technologies, including Node.js with the Socket.io module, HTML5 canvas, and jQuery, to provide a secure platform for pedagogical demonstrations and scalable, unsupervised experiment administration. Template code is provided for an example real-time behavioral game theory experiment which automatically pairs participants into dyads and places them into a virtual world. In total, this treatment is intended to allow those with a background in non-web-based programming to modify the template, which handles the technical server-client networking details, for their own experiments. PMID:25271089

Hawkins, Robert X D

2014-10-01

93

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

94

Conceptual Change Based on Laboratory Experience.  

ERIC Educational Resources Information Center

The purpose of this study was to examine the activities and discourse between scientists and high school student apprentices (from Santa Barbara, California) in research laboratories and how these supported and/or constrained student learning of science. The study covered 3 consecutive years of a summer science program and included 32 high school…

Bleicher, Robert E.

95

Laboratory experiments on nonlinear Electron MHD phenomena  

Microsoft Academic Search

In a large laboratory plasma highly nonlinear magnetic field-plasma interactions are studied in the regime of Electron MHD (EMHD). A pulsed magnetic field is applied with a loop antenna and the resultant field is measured with magnetic probes. Topologies of field-reversed configurations (FRC), spheromaks or strong mirrors are generated. These fields propagate as highly nonlinear whistler modes through the stationary

Reiner Stenzel

2006-01-01

96

Laboratory Experiences in Marine Biology, Student Edition.  

ERIC Educational Resources Information Center

This manual contains instructions for laboratory exercises using marine organisms. For each exercise a problem is defined, materials are listed, possible ways to solve the problem are suggested, questions are asked to guide the student in interpreting data, and further reading is suggested. The exercises deal with the measurement of oxygen…

Raimist, Roger J.

97

A Meaningful Experience in Laboratory Investigation  

ERIC Educational Resources Information Center

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

Szinai, S. S.; Szinai, N.

1976-01-01

98

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

99

Laboratory Impact Experiments: Collisional Processing of Simulated Cometary Materials  

NASA Astrophysics Data System (ADS)

While residing in the Kuiper Belt, an average comet (d=2 km) experiences tens to hundreds of impacts with d>8m objects over 3.5Gyr, while a typical Kuiper Belt Object (KBO) with d=200km undergoes 1x106 collisions. Durda and Stern (2000) suggest the interiors of most comet nuclei have been heavily damaged by collisions, and 1/3 of KBOs surfaces have been reworked. We have initiated a laboratory program dedicated to investigating the chemical, mineralogical, and spectral effects that impacts have had on comets and KBOs throughout their histories. Experiments were conducted at the NASA Johnson Space Center Experimental Impact Laboratory using the Vertical Impact gun. In phase 1, 16 experiments over a range of impact speeds (2.0 - 2.8 km/s) were conducted. Targets included refractory components found in comet dust, including Mg-rich olivine (forsterite) and pyroxene (enstatite), diopside, and Fe-rich sulfides (pyrrhotite). In phase 2, low-porosity, volatile-rich targets were constructed by mixing refractory dust components plus amorphous carbon, volatiles (H2O, CO2), and organics (PAHs). Targets were then insolated with a solar simulator to generate a layered target with a volatile-free crust above the volatile-rich base, and impacted. Analyses of pre- and post-impacted materials will be presented, including a) spectral changes, using a Fourier Transform Infrared Spectrometer (FTIR, 5 - 15 um) to investigate changes in slope, band depths, band shifting, and new signatures, b) the structural/shock-induced effects of the dust, through Transmission Electron Microscope (TEM) data, and c) compositional information via X-ray Diffraction lab studies. Phase 1 experiments demonstrate that silicate targets impacted at 2.45 and 2.8 km/s have been altered, causing changes in FTIR spectra (e.g., darkening, shallowing of band depths) and clear evidence of shock (high density of planar dislocations) in TEM images. This study was supported by a Cottrell College Science Award from Research Corporation and a NASA MUCERPI grant.

Lederer, Susan M.; Cintala, M. J.; Olney, R. D.; Nakamura-Messenger, K.; Smith, D. C.; Keller, L. P.; Zolensky, M. E.

2008-09-01

100

EFFECT OF FREEZE-THAW ON THE HYDRAULIC CONDUCTIVITY OF BARRIER MATERIALS: LABORATORY AND FIELD EVALUATION  

EPA Science Inventory

Laboratory tests were conducted on barrier materials to determine if their hydraulic conductivity changes as a result of freezing and thawing. esults of the tests were compared to data collected from a field study. ests were conducted on two compacted clays, one sand-bentonite mi...

101

Blanket technology experiments at Argonne National Laboratory  

SciTech Connect

Argonne National Laboratory has the largest US program for the development of blanket technology. The goals of the program are to resolve critical issues for different blanket concepts, to develop the understanding and predictive capability of blanket behavior, and to develop the technology needed to build and operate advanced fusion blankets. The projects within the program are liquid metal MHD, breeder neutronics, tritium oxidation, transient electromagnetics, FLIBE chemistry, and insulator coatings. The present status and recent results of the projects are described.

Mattas, R.F.; Reed, C.B.; Picologlou, B.; Finn, P.; Clemmer, R.; Porges, K.; Bennett, E.; Turner, L.R.

1988-02-01

102

Industrial Hygiene Laboratory accreditation: The JSC experience  

NASA Technical Reports Server (NTRS)

The American Industrial Hygiene Association (AIHA) is a society of professionals dedicated to the health and safety of workers and community. With more than 10,000 members, the AIHA is the largest international association serving occupational and environmental health professionals practicing industrial hygiene in private industry, academia, government, labor, and independent organizations. In 1973, AIHA developed a National Industrial Hygiene Laboratory Accreditation Program. The purposes of this program are shown.

Fadner, Dawn E.

1993-01-01

103

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

104

LABORATORY EXPERIMENT 4 Alkalimetric Titration of an Acid Mixture  

E-print Network

to semi-automatic volumetric analysis and potentiometric titrations. Phosphoric Acid, H3PO4 (pK1= 2.16, pLABORATORY EXPERIMENT 4 Alkalimetric Titration of an Acid Mixture In this experiment triprotic acid (H3PO4) will be determined by pH- potentiometric methods. This experiment will introduce you

Nazarenko, Alexander

105

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

106

Two laboratory experiments involving the homopolar generator  

Microsoft Academic Search

In these experiments numerical integration is used to verify Faraday's law of induction for the case of an open-circuit homopolar generator. The computed emfs are compared with experimentally measured values.

R. D. Eagleton

1987-01-01

107

Two laboratory experiments involving the homopolar generator  

NASA Astrophysics Data System (ADS)

In these experiments numerical integration is used to verify Faraday's law of induction for the case of an open-circuit homopolar generator. The computed emfs are compared with experimentally measured values.

Eagleton, R. D.

1987-07-01

108

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

109

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

110

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

111

Analytical study of the Atmospheric Cloud Physics Laboratory (ACPL) experiments  

NASA Technical Reports Server (NTRS)

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 is included.

Davis, M. H.

1977-01-01

112

Agreed Discoveries: Students' Negotiations in a Virtual Laboratory Experiment  

ERIC Educational Resources Information Center

This paper presents an analysis of the scientific reasoning of a dyad of secondary school students about the phenomenon of dissolution of gases in water as they work on this in a simulated laboratory experiment. A web-based virtual laboratory was developed to provide learners with the opportunity to examine the influence of physical factors on gas…

Karlsson, Goran; Ivarsson, Jonas; Lindstrom, Berner

2013-01-01

113

Location for the planned Space Experiment Research and Processing Laboratory  

NASA Technical Reports Server (NTRS)

This diagram shows the planned locations of the Space Experiment Research and Processing Laboratory (SERPL) and the Space Station Commerce Park at Kennedy Space Center. 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 the planned 400- acre commerce park.

2000-01-01

114

Research and the planned Space Experiment Research and Processing Laboratory  

NASA Technical Reports Server (NTRS)

Researchers perform tests at Kennedy Space Center. New facilities for such research will be provided 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

115

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

PubMed Central

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 poorly defined. To guide future reform efforts in this area, we conducted a national survey of biology faculty members to determine 1) their definitions of authentic research experiences in laboratory classes, 2) the extent of authentic research experiences currently experienced in their laboratory classes, and 3) the barriers that prevent incorporation of authentic research experiences into these classes. Strikingly, the definitions of authentic research experiences differ among faculty members and tend to emphasize either the scientific process or the discovery of previously unknown data. The low level of authentic research experiences in introductory biology labs suggests that more development and support is needed to increase undergraduate exposure to research experiences. Faculty members did not cite several barriers commonly assumed to impair pedagogical reform; however, their responses suggest that expanded support for development of research experiences in laboratory classes could address the most common barrier. PMID:24591509

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

2014-01-01

116

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

117

Laboratory Experiments for Network Security Instruction  

E-print Network

with an in-class demonstration of an attack by the instructor. Students then learn how to use open-source defense tools appropriate for the role they are playing and the attack at hand. Threats covered include that the experiments have statistically significant and large effect on students' learning. Moreover, surveys show

Brustoloni, José Carlos

118

"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

119

Laboratory Experiments and Hydrodynamic Modeling of a Bed Leveler Used to Level the Bottom of Ship Channels after Dredging  

E-print Network

modeling. The laboratory experiment was conducted to model how bed levelers interact with the ship channel bottom after hopper dredge dragheads (blades) made passes and created uneven trenches. These interactions were observed using both underwater and hand...

Paul, Ephraim Udo

2011-02-22

120

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...

121

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

122

Laboratory and Field Measurements of Soil Bulk Electrical Conductivity Using Time Domain Reflectometry  

NASA Astrophysics Data System (ADS)

As the increasing of contamination in soil and groundwater, there is a demand for fast, accurate, and cost-effective techniques for contaminated site investigation. Time domain reflectometry (TDR) is a nondestructive geophysical method that allows, in real time, simultaneous estimation of both the dielectric constant and the bulk soil electrical conductivity (EC). On such bases, TDR is a technique that could potentially be adapted for continuous monitoring of solute contaminants in soil and water. The objective of this study is to assess the performance of TDR for estimating the EC and the solute concentration through the laboratory experiments and then applied it to a field of mercury contamination in the sediments. Measurement of EC using TDR is based on the attenuation of the applied voltage as it traverses the medium of interest. Once the geometric constant of the probe can be determined and the mismatch of the TDR instrument can be corrected during the experimental setup, EC can easily be accurately evaluated through a single TDR measurement on the considered sample. The results obtained from the laboratory experiments showed the good agreement between the TDR measurement and conductivity meter, and the linear relationship between EC and solute concentration is also validated. Given a specific concentration of solution, the decrease of EC with the decrease of water content followed Archie's law. Experiments with releasing a pulse and continuous potassium nitrate solutions into a soil column were conducted to demonstrate the TDR capability of real time monitoring. The results showed that the breakthrough curve (BC) can be accurately and clearly delineated by the TDR measurement. In this study, the TDR application was also extended to a contaminated site in southern Taiwan. The mercury contaminated sediments were deposited at the bottom of saline lakes and the TDR probes were modified to overcome the measurement under the water. The field work showed that the spatial distribution of relative-high mercury concentrations could be identified by TDR. Although the absolute mercury concentration is still undetermined, but the feasibility of using TDR as a reference tool for contaminant site investigation and self-assessment of remediation was successfully demonstrated.

Hsu, S.; Chiu, Y.

2013-12-01

123

Experiment definition phase shuttle laboratory LDRL 10.6 experiment  

NASA Technical Reports Server (NTRS)

System optimization is reported along with mission and parameter requirements. Link establishment and maintenance requirements are discussed providing an acquisition and tracking scheme. The shuttle terminal configurations are considered and are included in the experiment definition.

1974-01-01

124

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.

125

Non-Radioactive DNA Hybridization Experiments for the Undergraduate Laboratory: The Southern Blot Analysis  

NSDL National Science Digital Library

This resource provides detailed instructions to conduct laboratory exercises leading to the detection of homologous DNA sequences via Southern blot analysis. Unlike standard protocols for Southern blotting, these experiments do not require students to handle radioactive materials, and is therefore a safer and less expensive alternative to standard methodologies.

Susan J. Karcher (Purdue University; )

1992-01-01

126

Laboratory Projects in Developing Inexpensive Control System Experiments  

E-print Network

, along with its supporting electronics. Humidity Control: Build a scale-model room, with windowsLaboratory Projects in Developing Inexpensive Control System Experiments Kevin M. Passino Dept@ece.osu.edu At OSU we have a project that focuses on the development of inexpensive control system experiments

127

Impact Crater Experiments for Introductory Physics and Astronomy Laboratories  

ERIC Educational Resources Information Center

Activity-based collisional analysis is developed for introductory physics and astronomy laboratory experiments. Crushable floral foam is used to investigate the physics of projectiles undergoing completely inelastic collisions with a low-density solid forming impact craters. Simple drop experiments enable determination of the average acceleration,…

Claycomb, J. R.

2009-01-01

128

Car-Crash Experiment for the Undergraduate Laboratory  

Microsoft Academic Search

An interesting, inexpensive, and highly motivating experiment for the undergraduate laboratory has been developed. Uniform and accelerated motion is studied in this experiment by measuring the position of a car as a function of time as it crashes into a rigid wall. The data are obtained from a sequence of pictures made by high speed cameras which recorded the actual

Penny L. Ball; Gary D. Doolen; Edward S. Fry; Marion D. Wedin

1974-01-01

129

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

130

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

131

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...

132

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

133

Spacecraft Dynamics as Related to Laboratory Experiments in Space. [conference  

NASA Technical Reports Server (NTRS)

Proceedings are presented of a conference sponsored by the Physics and Chemistry Experiments in Space Working Group to discuss the scientific and engineering aspects involved in the design and performance of reduced to zero gravity experiments affected by spacecraft environments and dynamics. The dynamics of drops, geophysical fluids, and superfluid helium are considered as well as two phase flow, combustion, and heat transfer. Interactions between spacecraft motions and the atmospheric cloud physics laboratory experiments are also examined.

Fichtl, G. H. (editor); Antar, B. N. (editor); Collins, F. G. (editor)

1981-01-01

134

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

135

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

136

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

137

Operating Experience of the Tritium Laboratory at CRL  

SciTech Connect

The Chalk River Laboratories Tritium Laboratory has been operating safely and reliably for over 20 years. Safe operations are achieved through proper management, supervision, training and using approved operating procedures and techniques. Reliability is achieved through appropriate equipment selection, routine equipment surveillance testing and routine preventative maintenance. This paper summarizes the laboratory's standard operating protocols and formal compliance programs followed to ensure safe operations. The paper will also review the general set-up of the laboratory and will focus on the experience gained with the operation of various types of equipment such as tritium monitors, tritium analyzers, pumps, purification systems and other systems used in the laboratory during its 20 years of operation.

Gallagher, C.L.; McCrimmon, K.D. [Atomic Energy of Canada Ltd. (Canada)

2005-07-15

138

Review of recent experiments on magnetic reconnection in laboratory plasmas  

SciTech Connect

The present paper reviews recent laboratory experiments on magnetic reconnection. Examples will be drawn from electron current sheet experiments, merging spheromaks, and from high temperature tokamak plasmas with the Lundquist numbers exceeding 10{sup 7}. These recent laboratory experiments create an environment which satisfies the criteria for MHD plasma and in which the global boundary conditions can be controlled externally. Experiments with fully three dimensional reconnection are now possible. In the most recent TFTR tokamak discharges, Motional Stark effect (MSE) data have verified the existence of a partial reconnection. In the experiment of spheromak merging, a new plasma acceleration parallel to the neutral line has been indicated. Together with the relationship of these observations to the analysis of magnetic reconnection in space and in solar flares, important physics issues such as global boundary conditions, local plasma parameters, merging angle of the field lines, and the 3-D aspects of the reconnection are discussed.

Yamada, M.

1995-02-01

139

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

140

On integrating LES and laboratory turbulent flow experiments  

SciTech Connect

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.

Grinstein, Fernando Franklin [Los Alamos National Laboratory

2008-01-01

141

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

142

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

143

Definition of experiments and instruments for a communication/navigation research laboratory. Volume 2: Experiment selection  

NASA Technical Reports Server (NTRS)

The selection and definition of candidate experiments and the associated experiment instrumentation requirements are described. Information is presented that addresses the following study objectives: (1) determine specific research and technology needs in the comm/nav field through a survey of the scientific/technical community; (2) develop manned low earth orbit space screening criteria and compile lists of potential candidate experiments; (3) in Blue Book format, define and describe selected candidate experiments in sufficient detail to develop laboratory configuration designs and layouts; and (4) develop experiment time phasing criteria and recommend a payload for sortie can/early laboratory missions.

1972-01-01

144

In situ and laboratory measurements of hydraulic conductivity in granitic rock matrix  

NASA Astrophysics Data System (ADS)

In the Czech Republic, granitic massifs are considered to provide the most suitable hosts for a radioactive waste repository. The aim of the current research project is to study the hydraulic properties of low-permeable rrock matrix. Field measurements of hydraulic conductivity were taken in boreholes while laboratory tests were undertaken on samples from the borehole cores. In the field, two boreholes with depths of 100 m were tested. The intergranular hydraulic conductivity was measured in 0.5 m long sections sealed by packers while the rock quality and position of cracks was determined by geophysical logging. In the laboratory, intergranular hydraulic conductivity was measured on homogenous samples in pressurised cells. A constant pressure gradient of ? = 50 kPa was kept between upper and lower bases and from this the average effective stress corresponded to the in situ effective stress. The use of field and laboratory methods allowed the results to be interpreted in detail. These have provided new information about microcrack networks and the intergranular hydraulic conductivity of granite matrix. The obtained data also revealed a significant scale effect that influences the hydraulic conductivities determined by the in situ and laboratory tests.

Zaruba, J.; Najser, J.; Rukavickova, L.; Sosna, K.

2012-12-01

145

BIOLOGICAL FRAMEWORKS FOR ENGINEERS Laboratory Experience #3 [Skeletal Muscle Biomechanics  

E-print Network

, is found to describe nearly all muscle thus far examined, include cardiac and smooth muscle as wellME498/599 BIOLOGICAL FRAMEWORKS FOR ENGINEERS Laboratory Experience #3 [Skeletal Muscle physiologic range of muscle lengths and arm positions. Study inverse relationship between load and velocity

Sniadecki, Nathan J.

146

BIOLOGICAL FRAMEWORKS FOR ENGINEERS Laboratory Experience #3 [Skeletal Muscle Biomechanics  

E-print Network

, is found to describe nearly all muscle thus far examined, include cardiac and smooth muscle as wellME411/511 BIOLOGICAL FRAMEWORKS FOR ENGINEERS Laboratory Experience #3 [Skeletal Muscle physiologic range of muscle lengths and arm positions. Study inverse relationship between load and velocity

Sniadecki, Nathan J.

147

LABORATORY EXPERIMENT 3 Alkalimetric Titration of an Acid  

E-print Network

LABORATORY EXPERIMENT 3 Alkalimetric Titration of an Acid A carbonate-free sodium hydroxide goal is to prepare a carbonate-free sodium hydroxide solution and standardize it. Sodium hydroxide solution is prepared and standardized. Preparation and standardization of sodium hydroxide solution. Our

Nazarenko, Alexander

148

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

149

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

150

LABORATORY EXPERIMENT 5 PRECIPITATION TITRATION WITH SILVER NITRATE.  

E-print Network

solution can be used for various titrations. I. Potentiometric Halide Titration with Ag+ MixturesLABORATORY EXPERIMENT 5 PRECIPITATION TITRATION WITH SILVER NITRATE. The AgNO3 solution (~0.02 M method with adsorption indicator and using Mohr method with chromate indicator. Both titrations

Nazarenko, Alexander

151

Human Gene Discovery Laboratory: A Problem-Based Learning Experience  

ERIC Educational Resources Information Center

A single-semester elective combines Mendelian and molecular genetics in a problem-solving format. Students encounter a genetic disease scenario, construct a family pedigree, and try to confirm their medical diagnoses through laboratory experiences. Encouraged to generate ideas as they test their hypotheses, students realize the importance of data…

Bonds, Wesley D., Sr.; Paolella, Mary Jane

2006-01-01

152

LABORATORY EXPERIMENT 7 Determination of Copper in Copper Alloys  

E-print Network

LABORATORY EXPERIMENT 7 Determination of Copper in Copper Alloys Two procedures for Cu determination in the same alloy sample will be used. Both are based on Cu2+ reduction. I. The Electrogravimetric Determination of Copper in Alloy A convenient example of an electrogravimetric method of analysis

Nazarenko, Alexander

153

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

154

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

155

A Unit Cell Laboratory Experiment: Marbles, Magnets, and Stacking Arrangements  

ERIC Educational Resources Information Center

An undergraduate first-semester general chemistry laboratory experiment introducing face-centered, body-centered, and simple cubic unit cells is presented. Emphasis is placed on the stacking arrangement of solid spheres used to produce a particular unit cell. Marbles and spherical magnets are employed to prepare each stacking arrangement. Packing…

Collins, David C.

2011-01-01

156

EDUCATIONAL EXPERIMENTS WITH AN ONLINE MICROELECTRONICS CHARACTERIZATION LABORATORY  

Microsoft Academic Search

We have developed and deployed an online microelectronics characterization laboratory that allows the characterization of transistors and other microelectronic devices in real time through the internet. The architecture of this system was devised to accomplish two goals: 1) the delivery of a rich educational experience in microelectronic device characterization to remote computers, and 2) the ability to scale to a

J. A. del Alamo; J. Hardison; G. Mishuris; L. Brooks; C. McLean; V. Chan; L. Hui

157

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

158

LABORATORY EXPERIMENT 6 PRECIPITATION TITRATION WITH SILVER NITRATE.  

E-print Network

LABORATORY EXPERIMENT 6 PRECIPITATION TITRATION WITH SILVER NITRATE. The AgNO3 solution (~0.02 M titrations are to be done in triplicate. I. Standardization of AgNO3 solution 1. The Determination of Chloride by Titration with an Adsorption Indicator Discussion In this titration, the anionic adsorption

Nazarenko, Alexander

159

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

160

Numerical support of laboratory experiments: Attenuation and velocity estimations  

NASA Astrophysics Data System (ADS)

We show that numerical support of laboratory experiments can significantly increase the understanding and simplify the interpretation of the obtained laboratory results. First we perform simulations of the Seismic Wave Attenuation Module to measure seismic attenuation of reservoir rocks. Our findings confirm the accuracy of this system. However, precision can be further improved by optimizing the sensor positions. Second, we model wave propagation for an ultrasonic pulse transmission experiment used to determine pressure- and temperature-dependent seismic velocities in the rock. Multiple waves are identified in our computer experiment, including bar waves. The metal jacket that houses the sample assembly needs to be taken into account for a proper estimation of the ultrasonic velocities. This influence is frequency-dependent.

Saenger, Erik H.; Madonna, Claudio; Frehner, Marcel; Almqvist, Bjarne S. G.

2014-02-01

161

Experiences and prospects of nuclear astrophysics in underground laboratories  

SciTech Connect

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. [INFN - Laboratori Nazionali del Gran Sasso, Via Acitelli, 22, 67100 L'Aquila, Località Assergi (Italy)

2014-05-09

162

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

163

Measurements of stem xylem hydraulic conductivity in the laboratory and field  

E-print Network

REVIEW Measurements of stem xylem hydraulic conductivity in the laboratory and field Peter J, Los Angeles, CA 90095, USA Summary 1. Xylem hydraulic properties play an essential role in supporting, on water transport. 2. We summarize the main methods currently in use for measurements of stem xylem

Sack, Lawren

164

ORGANOTIN TOXICITY STUDIES CONDUCTED WITH SELECTED MARINE ORGANISMS AT EPA'S ENVIRONMENTAL RESEARCH LABORATORY, GULF BREEZE, FLORIDA  

EPA Science Inventory

Studies on effect of bis(tri-n-butyltin)oxide (TBTO) and other organotins on marine species have been conducted at the U.S. Environmental Protection Agency's laboratory at Gulf Breeze, Florida, since 1983. First studies were done on two species of algae, Skeletonema costatum and ...

165

Modelling and laboratory experiments of astrophysical radiative shocks  

NASA Astrophysics Data System (ADS)

Radiative shocks might be encountered in various astrophysical systems. Therefore, there is a growing interest in producing radiative shocks in laboratory experiments as well as in modelling them with numerical simulations in order to calibrate and analyze the experiments. We present both simulations and an experiment of radiative shocks in xenon cell at low pressure. We first present the results obtained by the radiative shock experiment held at the PALS laser (Prague) in November 2005, where for the first time, the propagation of the shock was recorded over a very long period (40 ns). We then present simulations of this experiment performed using the radiation-hydrodynamics code HERACLES. We have shown, using these simulations, that multi-dimensional lateral radiative losses are determinant for the propagation of the radiative precursor. Assuming a wall transmision of 60% allows to reproduce very well the propagation of the radiative precursor and also gives a good agreement on the transmission coefficient upstream and inside the precursor.

González, M.; Stehlé, C.; Audit, E.; Busquet, M.; Rus, B.; Thais, F.

2006-06-01

166

Scaling astrophysical phenomena to high-energy-density laboratory experiments  

NASA Astrophysics Data System (ADS)

The spatial and temporal scales of astrophysical phenomena are typically 10-20 orders of magnitude greater than those of laboratory experiments intended to simulate them. Accordingly, the issue of similarity between the astrophysical phenomenon and its laboratory counterpart becomes quite important. Note also that in astrophysics, one is often dealing with highly dynamical systems, where orders of magnitude variation of the parameters of interest occurs over the duration of an event. In this regard, the similarity problem is more challenging than, say, the familiar problem of establishing a scaling law for the energy confinement time in a steady-state fusion device. We concentrate on astrophysical phenomena which can be reasonably well described by magnetohydrodynamic equations (like, e.g. propagation of the supernova (SN) shock through the progenitor star, and interaction of SN ejecta with an ambient plasma) and formulate a broad class of similarities that can be applied to them. We discuss issues of scalability in situations where the transition to turbulent flows occurs and present the corresponding constraints. We illustrate the general principles by describing several laboratory experiments carried out in a scaled fashion. Discussion of the possibility of scalable experiments directed towards studies of photo-evaporated molecular clouds (thought to be `star nurseries') is presented. An emphasis on the potential role of random magnetic fields is made. A concept of an experiment to generate magnetized jets in Z-pinch devices is presented.

Ryutov, D. D.; Remington, B. A.

2002-12-01

167

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

168

Copper sulphate reduces the metabolic activity of Gammarus fossarum in laboratory and field experiments.  

PubMed

The specialised fauna of freshwater springs is affected by contamination of the water with xenobiotics from human activities in the surrounding landscape. We assessed the effects of exposure to toxins in laboratory and field experiments by using copper sulphate as a model substance and Gammarus fossarum Koch, 1836, as the model organism. This amphipod is a common representative of the European spring fauna and copper is a widespread contaminant, mainly from agricultural practice. The experiments were conducted in test chambers placed in flow channels and directly in a spring. The gammarids were fed with conditioned beech leaf discs, which had been exposed to a 0.8mgCu/L solution for 96h. The feeding activity of the amphipods was quantified on the level of the organism; and the respiratory electron transport system (ETS) assay was conducted in order to determine changes on the cellular level in the test organisms. The results show that the feeding activity, when the leaf discs were contaminated with copper, was not significantly different from the control. The ETS activity of the gammarids, which had been feeding on the copper contaminated leaf discs was however significantly reduced. The results followed the same pattern for gammarids from both the laboratory and the spring. By conducting the experiments not only in a laboratory but also directly in a spring in the field, we took a crucial step towards a more realistic approach when examining environmental pollutants on an organism. Our findings demonstrate the importance of conducting experiments out in the field, in natural conditions, as well as in the laboratory. PMID:25704832

Schmidlin, Lara; von Fumetti, Stefanie; Nagel, Peter

2015-04-01

169

Electrical conductivity of lunar surface rocks - Laboratory measurements and implications for lunar interior temperatures  

NASA Technical Reports Server (NTRS)

Results are reported for laboratory measurements of the dc and low-frequency ac electrical conductivity of three lunar rocks with ferrous iron contents of 5 to 26 wt %. The measurements were made at temperatures ranging from 20 to 1000 C, and Mossbauer spectroscopy was used to determine the dependence of electrical conductivity on furnace atmosphere. It is found that the magnitude of electrical conductivity generally increases with increasing iron content. A comparison of the data on these samples with data on terrestrial olivines and pyroxenes shows that the electrical conductivity of anhydrous silicate minerals is influenced primarily by the concentration, oxidation state, and distribution of iron, while the silicate crystal structure is only of secondary importance. Lunar interior temperatures are deduced from experimental lunar conductivity profiles, and the resulting temperature-depth profiles are found to be consistent with those calculated for two different lunar evolutionary models as well as with various experimental constraints.

Schwerer, F. C.; Huffman, G. P.; Fisher, R. M.; Nagata, T.

1974-01-01

170

Simulated and Virtual Science Laboratory Experiments: Improving Critical Thinking and Higher-Order Learning Skills  

NASA Astrophysics Data System (ADS)

Virtual laboratory experiments using interactive computer simulations are not being employed as viable alternatives to laboratory science curriculum at extensive enough rates within higher education. Rote traditional lab experiments are currently the norm and are not addressing inquiry, Critical Thinking, and cognition throughout the laboratory experience, linking with educational technologies (Pyatt & Sims, 2007; 2011; Trundle & Bell, 2010). A causal-comparative quantitative study was conducted with 150 learners enrolled at a two-year community college, to determine the effects of simulation laboratory experiments on Higher-Order Learning, Critical Thinking Skills, and Cognitive Load. The treatment population used simulated experiments, while the non-treatment sections performed traditional expository experiments. A comparison was made using the Revised Two-Factor Study Process survey, Motivated Strategies for Learning Questionnaire, and the Scientific Attitude Inventory survey, using a Repeated Measures ANOVA test for treatment or non-treatment. A main effect of simulated laboratory experiments was found for both Higher-Order Learning, [F (1, 148) = 30.32,p = 0.00, eta2 = 0.12] and Critical Thinking Skills, [F (1, 148) = 14.64,p = 0.00, eta 2 = 0.17] such that simulations showed greater increases than traditional experiments. Post-lab treatment group self-reports indicated increased marginal means (+4.86) in Higher-Order Learning and Critical Thinking Skills, compared to the non-treatment group (+4.71). Simulations also improved the scientific skills and mastery of basic scientific subject matter. It is recommended that additional research recognize that learners' Critical Thinking Skills change due to different instructional methodologies that occur throughout a semester.

Simon, Nicole A.

171

COPE Coastal ocean probe experiment Northern Oregon Coast 14-16 September 1995: Test Operations Report summary of Lawrence Livermore National Laboratory activities  

Microsoft Academic Search

Operations involving Lawrence Livermore National Laboratory (LLNL) assets associated with a field experiment named COPE (Coastal Ocean Probe Experiment) are described. The lead organization responsible for the planning and conduct of COPE is NOAA\\/ETL headquartered in Boulder, Colorado. This experiment was conducted off the coast of Northern Oregon during September-October 1995. The primary measurements involve radars and other imaging microwave

D. D. Mantrom; M. G. Miller

1995-01-01

172

SUMMER 2004 RESEARCH EXPERIENCE FOR TEACHERS BROOKHAVEN NATIONAL LABORATORIES  

E-print Network

solid, liquid and gas, there is a fourth state of matter, called quark gluon plasma, QGP. The atom's alpha particle scattering experiments on thin gold foils led to the discovery of the nucleus. Electrons on Rutherford's discovery, accelerator physicists conducted nuclei collisions and found particles within

Cinabro, David

173

Radiative Shocks And Plasma Jets As Laboratory Astrophysics Experiments  

SciTech Connect

Dedicated laboratory astrophysics experiments have been developed at LULI in the last few years. First, a high velocity (70 km/s) radiative shock has been generated in a xenon filled gas cell. We observed a clear radiative precursor, measure the shock temperature time evolution in the xenon. Results show the importance of 2D radiative losses. Second, we developed specific targets designs in order to generate high Mach number plasma jets. The two schemes tested are presented and discussed.

Koenig, M.; Loupias, B.; Vinci, T.; Ozaki, N.; Benuzzi-Mounaix, A.; Rabec le Goahec, M. [Laboratoire pour l'Utilisation des Lasers Intenses, UMR7605, CNRS (United States); CEA - Universite Paris VI - Ecole Polytechnique, 91128 Palaiseau Cedex (France); Falize, E.; Bouquet, S.; Courtois, C. [CEA/DIF/ BP 12 91680 Bruyeres-le-Chatel (France); Michaut, C.; Herpe, G.; Baroso, P. [Laboratoire de l'Univers et de ses Theories, UMR8102, Observatoire de Paris, 92195 Meudon (France); Nazarov, W. [University of St Andrews, School of Chemistry, Purdie Building, North Haugh, St Andrews (United Kingdom); Aglitskiy, Y. [Science Applications International Corporation, McLean, Virginia 22102 (United States); Faenov, A. Ya.; Pikuz, T. [Joint Institute for High temperatures of RAS, Izhorskaya 13/19, Moscow, 125412 (Russian Federation); Woolsey, N. C.; Gregory, C. D.; Howe, J. [Department of Physics, University of York, Heslington, York, YO10 5DD (United Kingdom); Schiavi, A. [Dipartimento di Energetica, Universita' di Roma 'La Sapienza' (Italy); CNISM (Italy)] (and others)

2007-08-02

174

Differentiating biochemistry course laboratories based on student experience.  

PubMed

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 no experience with biochemical techniques and biology and biochemistry majors who do. This manuscript describes a strategy for differentiating biochemistry labs to meet the needs of students with differing backgrounds. PMID:21618386

Jakubowski, Henry V

2011-01-01

175

Connecting laboratory plasma experiments and astrophysical observations through computational modeling  

NASA Astrophysics Data System (ADS)

We describe an ongoing effort to increase synergy between laboratory measurements and astrophysical observations of magnetized plasmas by utilizing the available computational modeling capablity. Our goal is to directly relate physical insights derived from local measurements of reproducible plasmas in a controlled laboratory setting to remote observations of macroscopic dynamics of naturally occurring astrophysical plasmas, with particular emphasis on solar flares and CMEs. For this purpose, we use an initial value implicit adaptive multi-fluid MHD code HiFi for both 2D and 3D macroscopic simulations; as well as a particle-pushing code to track evolution of distributions of energetic particles in the dynamically evolving electro-magnetic fields computed with HiFi. We use the flexibilities afforded by the HiFi code, particularly in regard to various geometries, boundary conditions and specific systems of PDEs, to systematically study the effects of system's initial and boundary conditions on the plasma behavior both in laboratory and on the Sun. Additionally, we conduct limited scaling studies to determine how the various non-ideal effects, such as the plasma resistivity, anisotropic pressure tensor and heat conduction, affect the observable plasma characteristics in both systems. Early results and ongoing work will be presented. )

Lukin, V. S.; Linton, M. G.; Tylka, A. J.; Cothran, C. D.; Brown, M. R.

2010-02-01

176

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

Code of Federal Regulations, 2011 CFR

...area or areas in which the experiment is to be conducted; ...the effectiveness of the experiment; (7) The method for conveying to consumers...from the label during the experiment; (8) The method that will be or has...

2011-04-01

177

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

Code of Federal Regulations, 2013 CFR

...area or areas in which the experiment is to be conducted; ...the effectiveness of the experiment; (7) The method for conveying to consumers...from the label during the experiment; (8) The method that will be or has...

2013-04-01

178

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

Code of Federal Regulations, 2010 CFR

...area or areas in which the experiment is to be conducted; ...the effectiveness of the experiment; (7) The method for conveying to consumers...from the label during the experiment; (8) The method that will be or has...

2010-04-01

179

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

Code of Federal Regulations, 2012 CFR

...area or areas in which the experiment is to be conducted; ...the effectiveness of the experiment; (7) The method for conveying to consumers...from the label during the experiment; (8) The method that will be or has...

2012-04-01

180

Experiment of electrical conductivity at low temperature (preliminary measurement)  

SciTech Connect

A muon collider needs very large amount of RF power, how to reduce the RF power consumption is of major concern. Thus the application of liquid nitrogen cooling has been proposed. However, it is known that the electrical conductivity depends on many factors and the data from different sources vary in a wide range, especially the data of conductivity of beryllium has no demonstration in a real application. Therefore it is important to know the conductivity of materials, which are commercially available, and at a specified frequency. Here, the results of the preliminary measurement on the electrical conductivity of copper at liquid nitrogen temperature are summarized. Addressed also are the data fitting method and the linear expansion of copper.

Zhao, Y.; Wang, H.

1998-07-01

181

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

182

Review of laboratory experiments on Alfven's critical ionization velocity  

NASA Astrophysics Data System (ADS)

The progress of laboratory experiments on Alfven's Critical Ionization Velocity (CIV) of gas plasma interaction is reviewed. Since the first review by Danielsson (1973), in which the occurrence of the CIV phenomenon in crossed field discharges and in plasma-gas impact experiments was proved, most of the investigations have been directed towards clarifying the microscopic mechanism of the CIV by means of refined diagnostic techniques. The CIV interaction is identified - mostly by the plasma-gas impact experiments - to be a collisionless process, that leads to rapid electron heating, ionization and plasma braking. Turbulent electron heating by a modified two-stream instability is employed in modern CIV theories. Most of the experimental results presented corroborate the prevailance of this type of turbulent heating process.

Piel, A.

183

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

184

How to Conduct Clinical Qualitative Research on the Patient's Experience  

ERIC Educational Resources Information Center

From a perspective of patient-centered healthcare, exploring patients' (a) preconceptions, (b) treatment experiences, (c) quality of life, (d) satisfaction, (e) illness understandings, and (f) design are all critical components in improving primary health care and research. Utilizing qualitative approaches to discover patients' experiences can…

Chenail, Ronald J.

2011-01-01

185

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

186

Hydraulic Experiments for Determination of In-situ Hydraulic Conductivity of Submerged Sediments  

PubMed Central

A new type of in-situ hydraulic permeameter was developed to determine vertical hydraulic conductivity (VHC) of saturated sediments from hydraulic experiments using Darcy's law. The system allows water to move upward through the porous media filled in the permeameter chamber driven into sediments at water-sediment interface. Darcy flux and hydraulic gradient can be measured using the system, and the VHC can be determined from the relationship between them using Darcy's law. Evaluations in laboratory and in field conditions were performed to see if the proposed permeameter give reliable and valid measures of the VHC even where the vertical flow at water-sediment interface and fluctuation of water stage exist without reducing the accuracy of the derived VHC. Results from the evaluation tests indicate that the permeameter proposed in this study can be used to measure VHC of saturated sandy sediments at water-sediment interface in stream and marine environment with high accuracy. PMID:25604984

Lee, Bong-Joo; Lee, Ji-Hoon; Yoon, Heesung; Lee, Eunhee

2015-01-01

187

Hydraulic experiments for determination of in-situ hydraulic conductivity of submerged sediments.  

PubMed

A new type of in-situ hydraulic permeameter was developed to determine vertical hydraulic conductivity (VHC) of saturated sediments from hydraulic experiments using Darcy's law. The system allows water to move upward through the porous media filled in the permeameter chamber driven into sediments at water-sediment interface. Darcy flux and hydraulic gradient can be measured using the system, and the VHC can be determined from the relationship between them using Darcy's law. Evaluations in laboratory and in field conditions were performed to see if the proposed permeameter give reliable and valid measures of the VHC even where the vertical flow at water-sediment interface and fluctuation of water stage exist without reducing the accuracy of the derived VHC. Results from the evaluation tests indicate that the permeameter proposed in this study can be used to measure VHC of saturated sandy sediments at water-sediment interface in stream and marine environment with high accuracy. PMID:25604984

Lee, Bong-Joo; Lee, Ji-Hoon; Yoon, Heesung; Lee, Eunhee

2015-01-01

188

Hydraulic Experiments for Determination of In-situ Hydraulic Conductivity of Submerged Sediments  

NASA Astrophysics Data System (ADS)

A new type of in-situ hydraulic permeameter was developed to determine vertical hydraulic conductivity (VHC) of saturated sediments from hydraulic experiments using Darcy's law. The system allows water to move upward through the porous media filled in the permeameter chamber driven into sediments at water-sediment interface. Darcy flux and hydraulic gradient can be measured using the system, and the VHC can be determined from the relationship between them using Darcy's law. Evaluations in laboratory and in field conditions were performed to see if the proposed permeameter give reliable and valid measures of the VHC even where the vertical flow at water-sediment interface and fluctuation of water stage exist without reducing the accuracy of the derived VHC. Results from the evaluation tests indicate that the permeameter proposed in this study can be used to measure VHC of saturated sandy sediments at water-sediment interface in stream and marine environment with high accuracy.

Lee, Bong-Joo; Lee, Ji-Hoon; Yoon, Heesung; Lee, Eunhee

2015-01-01

189

Crossed-microwave-beam air ionization laboratory experiments  

SciTech Connect

Detailed laboratory measurements and theoretical modeling relevant to the production, geometrical description and decay of microwave-induced air ionization for an upper atmospheric RF reflecting layer are reported. It is found that breakdown thresholds are adequately predicted by fluid models and simplified scaling models with refinement by kinetic models being important at lower pressures. Repetitive pulse sustainment has been demonstrated to be straightforward with a commensurate reduction in sustainment power levels. However, establishment of a convenient breakdown geometry for specular RF reflections, other than a single layer in a crossed beam geometry, was not obtained. Detailed density decay measurements qualitatively support estimates of decay times and indicate ionization dwell times of tens of milliseconds. Chemistry studies indicate three N{sub x}O{sub x} species will be produced. Further study of these collateral reactions is required to establish whether adverse atmospheric consequences can result. However, large N{sub x}O{sub x} production does not appear as a concern for relatively small, low repetition rate, proof of concept atmospheric experiments. A realizable proof of concept experiment is found with simple optimization criteria which is corroborated by laboratory measurements and theoretical simulations. Tail-erosion appears as a potentially severe limitation in atmospheric experiments beyond the proof of concept level, suggesting use of multiple-beam systems. 20 refs., 18 figs.

Armstrong, W.T.; Karl, R.; Kelly, M.; Roussel-Dupre, R.; Buchwald, M.; Sutherland, C.D.; Zinn, J. (Los Alamos National Lab., NM (USA)); Alvarez, R.; Bolton, P.; Sieger, G.; Patterson, W. (Lawrence Livermore National Lab., CA (USA)); Hunton, D.; Trzcinski, E. (Air Force Geophysics Lab., Hanscom AFB, MA (USA)); Eckstrom, D.; Stalder, K. (SRI International, Menlo Park, CA (USA)); Testerman, L.; Tunnell, T.; Blain

1990-01-01

190

Payload specialist Sultan Abdelazize Al-Saud conducts Postural experiment  

NASA Technical Reports Server (NTRS)

Payload specialist Sultan Salman Abdelazize Al-Saud assists in conducting a French Postural Experement (FPE) on the middeck of the Space shuttle Discovery during the STS 51-G flight. Behind him on the middeck walls are two sleep restraints. At the bottom of the frame, foot restraints are visible.

1985-01-01

191

Payload specialists Baudry and Al-Saud conduct Postural experiment  

NASA Technical Reports Server (NTRS)

Payload specialists Patrick Baudry (left) and Sultan Salman Abdelazize Al-Saud team up to conduct a French Postural Experement (FPE) on the middeck of the Space shuttle Discovery during the STS 51-G flight. Behind them on the middeck walls are two sleep restraints.

1985-01-01

192

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

193

Guidelines and considerations for conducting experiments using tissue microarrays.  

PubMed

Tissue microarrays (TMAs) represent a powerful method for undertaking large-scale tissue-based biomarker studies. While TMAs offer several advantages, there are a number of issues specific to their use which need to be considered when employing this method. Given the investment in TMA-based research, guidance on design and execution of experiments will be of benefit and should help researchers new to TMA-based studies to avoid known pitfalls. Furthermore, a consensus on quality standards for TMA-based experiments should improve the robustness and reproducibility of studies, thereby increasing the likelihood of identifying clinically useful biomarkers. In order to address these issues, the National Cancer Research Institute Biomarker and Imaging Clinical Studies Group organized a 1-day TMA workshop held in Nottingham in May 2012. The document herein summarizes the conclusions from the workshop. It includes guidance and considerations on all aspects of TMA-based research, including the pre-analytical stages of experimental design, the analytical stages of data acquisition, and the postanalytical stages of data analysis. A checklist is presented which can be used both for planning a TMA experiment and interpreting the results of such an experiment. For studies of cancer biomarkers, this checklist could be used as a supplement to the REMARK guidelines. PMID:23672312

Ilyas, Mohammad; Grabsch, Heike; Ellis, Ian O; Womack, Chris; Brown, Robert; Berney, Dan; Fennell, Dean; Salto-Tellez, Manuel; Jenkins, Martin; Landberg, Goran; Byers, Richard; Treanor, Darren; Harrison, David; Green, Andrew R; Ball, Graham; Hamilton, Peter

2013-05-01

194

Safety Guidelines for Conducting Magnetic Resonance Imaging (MRI) Experiments Involving  

E-print Network

Risks 7 Risk Management 14 Emergencies 18 Contact With Body Fluids 20 Visitors 20 Summary of Safety-certified scanner operator. Since there is much more limited help or support available outside normal working hours, operators are expected to have a acquired considerable experience running the scanners during normal working

Squire, Larry R.

195

Laboratory plasma physics experiments using merging supersonic plasma jets  

NASA Astrophysics Data System (ADS)

We describe a laboratory plasma physics experiment at Los Alamos National Laboratory that uses two merging supersonic plasma jets formed and launched by pulsed-power-driven railguns. The jets can be formed using any atomic species or mixture available in a compressed-gas bottle and have the following nominal initial parameters at the railgun nozzle exit: ne ~ ni ~ 1016 cm-3, Te ~ Ti ~ 1.4 eV, V jet ~ 30-100 km/s, mean charge $\\bar{Z}$ ~ 1, sonic Mach number Ms ? V jet/Cs > 10, jet diameter = 5 cm, and jet length ~20 cm. Experiments to date have focused on the study of merging-jet dynamics and the shocks that form as a result of the interaction, in both collisional and collisionless regimes with respect to the inter-jet classical ion mean free path, and with and without an applied magnetic field. However, many other studies are also possible, as discussed in this paper.

Hsu, S. C.; Moser, A. L.; Merritt, E. C.; Adams, C. S.; Dunn, J. P.; Brockington, S.; Case, A.; Gilmore, M.; Lynn, A. G.; Messer, S. J.; Witherspoon, F. D.; Witherspoon

2015-04-01

196

Laboratory plasma physics experiments using merging supersonic plasma jets  

E-print Network

We describe a laboratory plasma physics experiment at Los Alamos National Laboratory that uses two merging supersonic plasma jets formed and launched by pulsed-power-driven rail guns. The jets can be formed using any atomic species or mixture available in a compressed-gas bottle and have the following nominal initial parameters at the railgun nozzle exit: $n_e\\approx n_i \\sim 10^{16}$ cm$^{-3}$, $T_e \\approx T_i \\approx 1.4$ eV, $V_{\\rm jet}\\approx 30$-100 km/s, mean charge $\\bar{Z}\\approx 1$, sonic Mach number $M_s\\equiv V_{\\rm jet}/C_s>10$, jet diameter $=5$ cm, and jet length $\\approx 20$ cm. Experiments to date have focused on the study of merging-jet dynamics and the shocks that form as a result of the interaction, in both collisional and collisionless regimes with respect to the inter-jet classical ion mean free path, and with and without an applied magnetic field. However, many other studies are also possible, as discussed in this paper.

Hsu, S C; Merritt, E C; Adams, C S; Dunn, J P; Brockington, S; Case, A; Gilmore, M; Lynn, A G; Messer, S J; Witherspoon, F D

2014-01-01

197

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,

198

Impact of flow velocity on biochemical processes - a laboratory experiment  

NASA Astrophysics Data System (ADS)

Understanding and predicting hydraulic and chemical properties of natural environments are current crucial challenges. It requires considering hydraulic, chemical and biological processes and evaluating how hydrodynamic properties impact on biochemical reactions. In this context, an original laboratory experiment to study the impact of flow velocity on biochemical reactions along a one-dimensional flow streamline has been developed. Based on the example of nitrate reduction, nitrate-rich water passes through plastic tubes at several flow velocities (from 6.2 to 35 mm min-1), while nitrate concentration at the tube outlet is monitored for more than 500 h. This experimental setup allows assessing the biologically controlled reaction between a mobile electron acceptor (nitrate) and an electron donor (carbon) coming from an immobile phase (tube) that produces carbon during its degradation by microorganisms. It results in observing a dynamic of the nitrate transformation associated with biofilm development which is flow-velocity dependent. It is proposed that the main behaviors of the reaction rates are related to phases of biofilm development through a simple analytical model including assimilation. Experiment results and their interpretation demonstrate a significant impact of flow velocity on reaction performance and stability and highlight the relevance of dynamic experiments over static experiments for understanding biogeochemical processes.

Boisson, A.; Roubinet, D.; Aquilina, L.; Bour, O.; Davy, P.

2014-08-01

199

Modification of sandy soil hydrophysical environment through bagasse additive under laboratory experiment  

NASA Astrophysics Data System (ADS)

Until now sandy soils can be considered as one roup having common hydrophysical problems. Therefore, a laboratory experiment was conducted to evaluate the influence of bagasse as an amendment to improve hydrophysical properties of sandy soil, through the determination of bulk density, aggregatesize distribution, total porosity, hydraulic conductivity, pore-space structure and water retention. To fulfil this objective, sandy soils were amended with bagasse at the rate of 0, 0.5, 1, 2, 3 and 4% on the dry weight basis. The study results demonstrated that the addition of bagasse to sandy soils in between 3 to 4% on the dry weight basis led to a significant decrease in bulk density, hydraulic conductivity, and rapid-drainable pores, and increase in the total porosity, water-holding pores, fine capillary pores, water retained at field capacity, wilting point, and soil available water as compared with the control treatment

Abd El-Halim, A. A.; Kumlung, Arunsiri

2015-01-01

200

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

201

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

202

Heterogeneous ice nucleation parameterizations based on laboratory experiments  

NASA Astrophysics Data System (ADS)

Aerosol influences on mixed-phase and cold clouds have received increasing attention in recent years. Possible effects of anthropogenic aerosols include enhanced glaciation of mixed-phase clouds, deactivation of natural ice nuclei, or they could be negligible compared to the natural background. The numerical simulation and quantification of these effects requires aerosol-specific ice nucleation parameterizations, which can be based either on field measurements or on laboratory experiments. The advantage of laboratory studies is that the aerosol samples can be well characterized with respect to their composition and size distribution. A simple empirical parameterization of ice nucleation ability is the so-called active site density. Experiments in the AIDA (Aerosol Interaction and Dynamics in the Atmosphere) chamber have been used as a basis for fitted active site densities for various particles, such as desert dusts, volcanic ash, agricultural soils and pollen grains. The parameterizations will be compared to results from other experiments, and the differences and limitations will be discussed. The derived values of the active site density are sensitive to assumptions on the particle shape. In addition, the temperature range which can be covered is limited by the detection threshold of the employed instrument. For deposition nucleation, it is more difficult to obtain temperature- and supersaturation-dependent fits of the active site density. Furthermore, other recently developed ice nucleation parameterizations (Phillips et al, 2008; DeMott et al, 2010; Hoose et al, 2010), which are based on continuous flow diffusion chamber measurements and classical nucleation theory, respectively, are presented as "equivalent active site densities" to make them directly comparable to the AIDA measurements and active site density fits. These approaches differ both with respect to their absolute values, temperature- and time-dependence. The resultant differences in predicted atmospheric ice nuclei concentrations will be shown for a simulation with the COSMO-ART model.

Hoose, C.; Möhler, O.; Niemand, M.; Steinke, I.

2012-04-01

203

Manifested Intra-Group Conflict in Collaborative Technology Supported MultiCultural Virtual Teams: Findings from a Laboratory Experiment  

Microsoft Academic Search

In this paper, we report the findings of our study on perceived group atmosphere and manifested intra-group conflict in global virtual teams, engaged in non-repetitive task. We conducted a laboratory experiment in which global virtual teams used IBM's Lotus Sametime to perform group tasks. We found that cultural heterogeneity of the virtual teams adversely affected members' perception of the group

Souren Paul; Sumati Ray

2010-01-01

204

Fossil Energy R&D at Oak Ridge National Laboratory The Oak Ridge National Laboratory's Fossil Energy Program conducts research and development that  

E-print Network

Fossil Energy R&D at Oak Ridge National Laboratory The Oak Ridge National Laboratory's Fossil Energy Program conducts research and development that contribute to the advancement of fossil energy and technologies for the sustainable production and use of fossil energy resources. ORNL works with the US

205

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

206

Exploring eddy radii in laboratory rotating tank experiments  

NASA Astrophysics Data System (ADS)

Radii of eddies created in the laboratory by removal of fluid at a surface sink are often substantially smaller than the radius of deformation suggesting that friction plays a more substantial role in setting laboratory eddy scales than it does in the ocean. In order to better understand the processes involved, the radii of anticyclonic eddies were examined in a one meter tank at the University of Rhode Island Geophysical Fluid Dynamics Laboratory. The removal of fluid at the surface was accomplished via a small tube placed at the center of the rotating tank and the horizontal velocity field was measured with a PIV (Particle Image Velocimetry) system. The parameter range explored covered rotation rates from 0.25 to 2.0 s-1; withdrawal rates of 53 to 435 ml/min, and fluid depths from 8 to 32cm. The deformation radii associated with these parameters range from ~22 to ~360cm. The eddy radius was defined at the point at which the azimuthal velocity about the eddy center reaches its maximum. This also corresponds to the point at which the bottom Ekman layer switches from convergence to divergence. The results show that eddy radii depend on the square root of the withdrawal rate and are only weakly dependent on the rotation rate. (Experiments involving the effect of fluid depth on eddy radius, if any, were not analyzed at the time of the writing of this abstract but will be included in the poster presentation.) Theoretical arguments are presented to explain the observed behavior.

Warner, J.; Salter, J.; Cornillon, P. C.; Stewart, K.; Rothstein, L.; Iwanski, D.

2012-12-01

207

The ICARUS Experiment at the Gran Sasso Underground Laboratory  

NASA Astrophysics Data System (ADS)

The present ICARUS detector, called T600, is ready for installation in the Gran Sasso underground laboratory. It consists of two large cryostats, each one filled with 300 tons of Liquid Argon and equipped with two Time Projection Chambers (TPCs). An overview of the T600 detector is given. Main results of the analyses of the data collected during the surface tests with cosmic rays in summer 2001 are presented. They illustrate the detector's excellent performance. A vast physics program of the ICARUS experiment, which includes different aspects of the neutrino studies and searches for proton decays, is shortly discussed. Finally, the detector upgrade towards the total mass of 3000 tons of Liquid Argon is mentioned.

Zalewska, A.

2004-06-01

208

Seeded FEL Microbunching Experiments at the UCLA Neptune Laboratory  

SciTech Connect

Seeded high-gain FELs, which can generate very powerful radiation pulses in a relatively compact undulator and simultaneously modulate the electron beam longitudinally at the seed wavelength, are important tools for advanced accelerator development. A single-pass 0.5-9 THz FEL amplifier-buncher driven by a regular photoinjector is being built at the UCLA Neptune Laboratory. FEL interactions at 340 {mu}m (1 THz) are considered for the first experiment, since time-resolved measurements of longitudinal current distribution of the bunched beam using the RF deflecting cavity are possible. A design of a 0.2-2.0 {mu}m FEL using the same undulators is presented. In this case the FEL is driven by a high-peak current beam from the laser-plasma accelerator tunable in the 100-300 MeV range.

Tochitsky, S. Ya.; Musumeci, P.; Rosenzweig, J. B.; Joshi, C. [Neptune Laboratory, Departments of Electrical Engineering and Physics, University of California, Los Angeles, CA 90095 (United States); Gottschalk, S. C. [STI Optronics, Inc., Bellevue, WA 98004-1495 (United States)

2010-11-04

209

Magnetic shielding of a laboratory Hall thruster. II. Experiments  

NASA Astrophysics Data System (ADS)

The physics of magnetic shielding in Hall thrusters were validated through laboratory experiments demonstrating essentially erosionless, high-performance operation. The magnetic field near the walls of a laboratory Hall thruster was modified to effectively eliminate wall erosion while maintaining the magnetic field topology away from the walls necessary to retain efficient operation. Plasma measurements at the walls validate our understanding of magnetic shielding as derived from the theory. The plasma potential was maintained very near the anode potential, the electron temperature was reduced by a factor of two to three, and the ion current density was reduced by at least a factor of two. Measurements of the carbon backsputter rate, wall geometry, and direct measurement of plasma properties at the wall indicate that the wall erosion rate was reduced by a factor of 1000 relative to the unshielded thruster. These changes effectively eliminate wall erosion as a life limitation in Hall thrusters, enabling a new class of deep-space missions that could not previously be attempted.

Hofer, Richard R.; Goebel, Dan M.; Mikellides, Ioannis G.; Katz, Ira

2014-01-01

210

Magnetic shielding of a laboratory Hall thruster. II. Experiments  

SciTech Connect

The physics of magnetic shielding in Hall thrusters were validated through laboratory experiments demonstrating essentially erosionless, high-performance operation. The magnetic field near the walls of a laboratory Hall thruster was modified to effectively eliminate wall erosion while maintaining the magnetic field topology away from the walls necessary to retain efficient operation. Plasma measurements at the walls validate our understanding of magnetic shielding as derived from the theory. The plasma potential was maintained very near the anode potential, the electron temperature was reduced by a factor of two to three, and the ion current density was reduced by at least a factor of two. Measurements of the carbon backsputter rate, wall geometry, and direct measurement of plasma properties at the wall indicate that the wall erosion rate was reduced by a factor of 1000 relative to the unshielded thruster. These changes effectively eliminate wall erosion as a life limitation in Hall thrusters, enabling a new class of deep-space missions that could not previously be attempted.

Hofer, Richard R., E-mail: richard.r.hofer@jpl.nasa.gov; Goebel, Dan M.; Mikellides, Ioannis G.; Katz, Ira [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)

2014-01-28

211

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

212

Integrating responsible conduct of research education into undergraduate biochemistry and molecular biology laboratory curricula.  

PubMed

Recently, a requirement for directed responsible conduct in research (RCR) education has become a priority in the United States and elsewhere. In the US, both the National Institutes of Health and the National Science Foundation require RCR education for all students who are financially supported by federal awards. The guidelines produced by these agencies offer useful templates for the introduction of RCR materials into courses worldwide. Many academic programs already offer courses or workshops in RCR for their graduate students and for undergraduate science majors and/or researchers. Introducing RCR into undergraduate biochemistry and molecular biology laboratory curricula is another, highly practical way that students can be exposed to these important topics. In fact, a strong argument can be made for integrating RCR into laboratory courses because these classes often introduce students to a scientific environment like that they might encounter in their careers after graduation. This article focuses on general strategies for incorporating explicit RCR education into biochemistry and molecular biology laboratory coursework using the topics suggested by NIH as a starting point. © 2015 by The International Union of Biochemistry and Molecular Biology, 43(2):68-75, 2015. PMID:25727192

Hendrickson, Tamara L

2015-03-01

213

Comparisons of laboratory bioassays and a whole-lake experiment: Rotifer responses to experimental acidification  

SciTech Connect

The authors test whether data from laboratory bioassays can be used to predict zooplankton responses during a whole-lake experiment using two rotifers, Keratella cochlearis and Keratella taurocephala. The acidification experiment was conducted in Little Rock Lake, Wisconsin, USA, which was divided into a reference basin maintained at a natural pH near 6.1 and a treatment basin which was acidified in 2-yr stages to pH values of 5.6, 5.2, and 4.7. Laboratory assays examined the effect of pH on reproduction under varied food conditions and survivorship without food. In the lake, the two rotifers showed strong and opposite responses to acidification: K. cochlearis decreased in abundance while K. taurocephala increased. In the laboratory bioassays, neither species was sensitive to pH when food conditions yielded high reproductive rates. When food was limited, K. cochlearis exhibited lower survivorship and a trend towards lower reproductive rates at lower pH. With limited food, K. taurocephala survivorship was either unaffected by pH or higher at high pH and its reproduction was slightly higher at intermediate pH. In situ experiments revealed that food conditions in the treatment basin lowered reproduction by K. cochlearis, indicating that a combined effect of food and pH caused its population decline. Neither food nor pH could explain the increase in K. taurocephala, which appeared to be linked to a reduction in its predators at lower pH. Overall, the analyses revealed substantial discrepancies between laboratory bioassays and in-lake responses. This was particularly the case for K. taurocephala, for which assays predicted no changes or a decline in abundance rather than the marked increase that actually occurred. The results suggest that caution should be used in extending results from laboratory assays to natural ecosystems.

Gonzalez, M.J.; Frost, T.M. (Univ. of Wisconsin, Madison, WI (United States))

1994-02-01

214

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

215

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

216

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

217

Laboratory modelling experiments on the flow generated by the tidal motion of a stratified ocean over a continental shelf  

Microsoft Academic Search

Laboratory model experiments have been conducted to investigate the interaction of a tidally forced stratified flow with a continental shelf. Results collected from a wide range of parametric experiments covering sub-, critical and super-critical tidal forcing are presented to show that the resulting flow regimes can be classified conveniently by the dimensionless parameters Fr=Usb\\/cw and ?=?2\\/N02?, where Usb is the

Yakun Guo; Peter A Davies

2003-01-01

218

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

219

Photocatalytic Hydrogen Production by Direct Sunlight: A Laboratory Experiment  

NASA Astrophysics Data System (ADS)

The demand for hydrogen will increase within the next decades as a result of the necessity to produce clean and environmentally and economically accepted fuels from natural and renewable energy resources. In principle, hydrogen has the potential to play an important role in future energy systems because of the diversity of its applications, the variety of ways in which it can be stored, its general environmental advantages, and especially because of the possibility of producing hydrogen by splitting water using photocatalysts and solar energy. Methods and techniques of photocatalytic reactions are covered in some detail in many undergraduate chemistry programs. However, many times in instructional settings, little attention is given to how it is used for the production of hydrogen. In the present investigation a photocatalytic hydrogen production experiment suitable for use in undergraduate chemistry laboratories is described. The experiment can be used to introduce students to the concept of a renewable and sustainable hydrogen energy system of the future, as well as its production techniques, and to demonstrate the use of a CdS/ZnS photocatalyst system for photocatalytic hydrogen production from direct sunlight.

Koca, Atif; Sahin, Musa

2003-11-01

220

Laboratory experiments on the breakup of liquid metal diapirs  

NASA Astrophysics Data System (ADS)

The validity of the iron rain scenario, i.e. the widely accepted model for the dynamics of iron sedimentation through a magma ocean during the latest stage of the Earth's accretion, is explored via a suite of laboratory experiments. Liquid gallium and mixtures of water and glycerol are used as analogs of the iron and the molten silicate respectively. This allows us to investigate the effects of the viscosity ratio between iron and silicate and to reproduce the relevant effects of surface tension on the fragmentation dynamics. While the classical iron rain scenario considers a population of purely spherical drops with a single characteristic radius that fall towards the bottom of the magma ocean at a unique velocity without any further change, our experiments exhibit a variety of stable shapes for liquid metal drops, a large distribution of sizes and velocities, and an intense internal dynamics within the cloud with the superimposition of further fragmentations and merging events. Our results demonstrate that rich and complex dynamics occur in models of molten metal diapir physics. Further, we hypothesize that the inclusion of such flows into state of the art thermochemical equilibration models will generate a similarly broad array of complex, and likely novel, behaviors.

Wacheul, Jean-Baptiste; Le Bars, Michael; Monteux, Julien; Aurnou, Jonathan M.

2014-10-01

221

A laboratory plasma experiment for studying magnetic dynamics of accretion discs and jets  

E-print Network

A laboratory plasma experiment for studying magnetic dynamics of accretion discs and jets S. C. Hsu T This work describes a laboratory plasma experiment and initial results which should give insight gun. Key words: accretion, accretion discs ­ MHD ­ plasmas ­ methods: laboratory. 1 I NT RODU CTION

Hsu, Scott

222

Intermediate-Scale Laboratory Experiments of Subsurface Flow and Transport Resulting from Tank Leaks  

SciTech Connect

Washington River Protection Solutions contracted with Pacific Northwest National Laboratory to conduct laboratory experiments and supporting numerical simulations to improve the understanding of water flow and contaminant transport in the subsurface between waste tanks and ancillary facilities at Waste Management Area C. The work scope included two separate sets of experiments: •Small flow cell experiments to investigate the occurrence of potential unstable fingering resulting from leaks and the limitations of the STOMP (Subsurface Transport Over Multiple Phases) simulator to predict flow patterns and solute transport behavior under these conditions. Unstable infiltration may, under certain conditions, create vertically elongated fingers potentially transporting contaminants rapidly through the unsaturated zone to groundwater. The types of leak that may create deeply penetrating fingers include slow release, long duration leaks in relatively permeable porous media. Such leaks may have occurred below waste tanks at the Hanford Site. •Large flow experiments to investigate the behavior of two types of tank leaks in a simple layered system mimicking the Waste Management Area C. The investigated leaks include a relatively large leak with a short duration from a tank and a long duration leak with a relatively small leakage rate from a cascade line.

Oostrom, Martinus; Wietsma, Thomas W.

2014-09-30

223

Sodium Concentration Measurement during Hemodialysis through Ion-Exchange Resin and Conductivity Measure Approach: In Vitro Experiments  

PubMed Central

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

224

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 14, 2014. Its landing feet house the triaxial acceleration sensors of CASSE (Comet Acoustic Surface Sounding Experiment [1]) 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 (Figure 1).

Knapmeyer, M.; Faber, C.; Witte, L.; Schröder, S.; Tune, J.-B.; Möhlmann, D.; Arnold, W.; Roll, R.; Chares, B.; Fischer, H.-H.; Seidensticker, K. J.

2013-09-01

225

Microwave-based laboratory experiments for internally-heated mantle convection  

SciTech Connect

The thermal evolution of terrestrial planets is mainly controlled by the amount of radioactive heat sources in their mantle, and by the geometry and efficiency of solid state thermo-chemical convection within. So far, these systems have been studied using numerical methods only and cross validation by laboratory analogous experiments has not been conducted yet. To fill this gap we perform the first laboratory experiments of mantle convection driven by microwave-generated internal heating. We use a 30×30×5 cm{sup 3} experimental tank filled with 0.5 % Natrosol in water mixture (viscosity 0.6 Pa.s at 20°C). The fluid is heated from within by a microwave device that delivers a uniform volumetric heating from 10 to 70 kW/m{sup 3}; the upper boundary of the fluid is kept at constant temperature, whereas the lower boundary is adiabatic. The velocity field is determined with particle image velocimetry and the temperature field is measured using thermochromic liquid crystals which enable us to charaterize the geometry of the convective regime as well as its bulk thermal evolution. Numerical simulations, conducted using Stag-3D in 3D cartesian geometry, reproduce the experimental setup (i.e., boundary conditions, box aspect ratio, temperature dependence of physical parameters, internal heating rate). The successful comparison between the experimental and numerical results validates our approach of modelling internal heating using microwaves.

Limare, A.; Di Giuseppe, E.; Vilella, K.; Farnetani, C. G.; Kaminski, E.; Jaupart, C. [Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris-Diderot, CNRS, 1 rue Jussieu, F-75005 Paris (France)] [Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris-Diderot, CNRS, 1 rue Jussieu, F-75005 Paris (France); Surducan, E.; Surducan, V.; Neamtu, C. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)] [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)

2013-11-13

226

Plasmid Instability in Batch Cultures of Recombinant Bacteria. A Laboratory Experiment.  

ERIC Educational Resources Information Center

Described is a laboratory experiment designed to expose students to problem-solving methods individually and as a group. Included are background information, a list of materials, laboratory procedures, analysis methods, and probable results. (CW)

Bentley, William E.; Kompala, Dhinakar S.

1990-01-01

227

Analyzing Fault Gouge Under Seismic Conditions in Laboratory Experiments  

NASA Astrophysics Data System (ADS)

The slip along a fault zone during an earthquake is associated with dense granular flow of the fault gouge. The gouge is a mixture of powder formed during prior slip as well as the dynamic rupture in the process zone of the propagating earthquake. Experimental tests of dense granular flow are usually conducted under low to moderate shear-rates and under low to vanishing normal stresses, and commonly without confinement. These experimental conditions do not match the conditions of natural earthquakes: slip of a few meters; normal stress of tens to hundreds MPa; slip velocity of ~1 m/s; rise time < 1 sec; and elevated, undrained fluid pressure. We build an apparatus for testing the mechanical behavior of fault gouge (and other dense granular materials) under these natural conditions. The apparatus has the following capabilities: (1) Control of fluid pore pressure in the gouge by leak-proof design for dry, wet, or partially saturated experiments, and control of pore pressure in wet experiments; (2) Continuously variable speed control 0.01- 1.5 m/s: (3) Cumulative slip up to 10 m; (4) Normal stress up to 30 MPa; (5) fast step-loading (short rise- time); and (6) Testing either gouge or solid rocks. We use this instrument to test weakening mechanisms during earthquake slip. Preliminary experimental results will be presented.

Reches, Z.; Lockner, D. A.; Young, J.; Eshkol, E.; Hamilton, M. E.; Fagan, J.

2008-12-01

228

Laboratory experiments designed to test the remediation properties of materials  

SciTech Connect

Passive treatment systems constructed to remediate mine drainage have proven to be very successful for a wide variety of drainage compositions and volumes. The construction of an anaerobic passive treatment system requires a mixture of local materials with the objective of producing a system that allows adequate water flow while supporting the growth of sulfate-reducing bacteria. These bacteria have the effect of reducing the oxidizing potential in the system causing many sulfide-forming metals in solution to precipitate. The focus of these experiments was the study of chemical characteristics of materials, individually and in mixtures, with the purpose of determining which would be best suited for incorporation into a treatment system. The materials of interest were manure (fresh and aged), alfalfa, limestone, and sawdust, which were all collected in close proximity to the construction site of the proposed treatment system. A variety of chemical and physical hypotheses were formulated prior to performing simple chemical characterization and anaerobic treatment tests. The hypotheses relating to the chemical nature of the single materials were carbon to nitrogen ratio, availability of low molecular weight organic acids, number of adsorption sites, and organic carbon content. In addition, hypotheses concerning the performance of mixtures were evaluated by looking at the relative amount of bacterial growth (and metal removal) seen in each mixture over a 4-week period. The results of the laboratory experiments confirmed hypotheses, and demonstrated that in the mixtures, the anaerobic bacteria flourish when alfalfa is present, up to a point. The best mixture that allowed proliferation of bacteria while also removing metals consisted of 50% limestone, 25% aged manure, 15% sawdust, and 10% alfalfa (% by weight).

Gilbert, J.S.; Wildeman, T.R.; Ford, K.L.

1999-07-01

229

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

SciTech Connect

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. [Luxim Corporation, Sunnyvale, California 94024 (United States) [Luxim Corporation, Sunnyvale, California 94024 (United States); Lawrence Berkeley National Laboratory, California 94720 (United States); Alexander, N. [General Atomics, San Diego, California 92121 (United States)] [General Atomics, San Diego, California 92121 (United States); Barnard, J. J.; Lund, S. M. [Lawrence Livermore National Laboratory, California 94550 (United States)] [Lawrence Livermore National Laboratory, California 94550 (United States)

2014-05-15

230

Integration of a fin experiment into the undergraduate heat transfer laboratory  

Microsoft Academic Search

A fin experimental apparatus was designed, developed and constructed for the undergraduate heat transfer laboratory at Purdue University at Fort Wayne. This paper presents a fin experiment that can be integrated into the undergraduate heat transfer laboratory. The objective of this experiment is to enhance the understanding of the transfer of thermal energy by undergraduate mechanical engineering students. This experiment

H. I. Abu-Mulaweh

231

Investigating vortex streets behind real and virtual bluff bodies: An experiment for an advanced undergraduate laboratory  

E-print Network

laboratory and to introduce students to methods of dimensional analysis. While the experiment is simple1 Investigating vortex streets behind real and virtual bluff bodies: An experiment for an advanced@physics.mun.ca Abstract This paper describes a laboratory experiment designed to study regular arrays of vortices

deYoung, Brad

232

Emulating JWST Exoplanet Transit Observations in a Testbed laboratory experiment  

NASA Astrophysics Data System (ADS)

The transit technique is used for the detection and characterization of exoplanets. The combination of transit and radial velocity (RV) measurements gives information about a planet's radius and mass, respectively, leading to an estimate of the planet's density (Borucki et al. 2011) and therefore to its composition and evolutionary history. Transit spectroscopy can provide information on atmospheric composition and structure (Fortney et al. 2013). Spectroscopic observations of individual planets have revealed atomic and molecular species such as H2O, CO2 and CH4 in atmospheres of planets orbiting bright stars, e.g. Deming et al. (2013). The transit observations require extremely precise photometry. For instance, Jupiter transit results to a 1% brightness decrease of a solar type star while the Earth causes only a 0.0084% decrease (84 ppm). Spectroscopic measurements require still greater precision <30ppm. The Precision Projector Laboratory (PPL) is a collaboration between the Jet Propulsion Laboratory (JPL) and California Institute of Technology (Caltech) to characterize and validate detectors through emulation of science images. At PPL we have developed a testbed to project simulated spectra and other images onto a HgCdTe array in order to assess precision photometry for transits, weak lensing etc. for Explorer concepts like JWST, WFIRST, EUCLID. In our controlled laboratory experiment, the goal is to demonstrate ability to extract weak transit spectra as expected for NIRCam, NIRIS and NIRSpec. Two lamps of variable intensity, along with spectral line and photometric simulation masks emulate the signals from a star-only, from a planet-only and finally, from a combination of a planet + star. Three masks have been used to simulate spectra in monochromatic light. These masks, which are fabricated at JPL, have a length of 1000 pixels and widths of 2 pixels, 10 pixels and 1 pixel to correspond respectively to the noted above JWST instruments. From many-hour long observing sequences, we obtain time series photometry with deliberate offsets introduced to test sensitivity to pointing jitter and other effects. We can modify the star-planet brightness contrast by factors up to 10^4:1. With cross correlation techniques we calculate positional shifts which are then used to decorrelate the effects of vertical and lateral offsets due to turbulence and instrumental vibrations on the photometry. Using Principal Component Analysis (PCA), we reject correlated temporal noise to achieve a precision lower than 50 ppm (Clanton et al. 2012). In our current work, after decorrelation of vertical and lateral offsets along with PCA, we achieve a precision of sim20 ppm. To assess the photometric precision we use the Allan variance (Allan 1987). This statistical method is used to characterize noise and stability as it indicates shot noise limited performance. Testbed experiments are ongoing to provide quantitative information on the achievable spectroscopic precision using realistic exoplanet spectra with the goal to define optimized data acquisition sequences for use, for example, with the James Webb Space Telescope.

Touli, D.; Beichman, C. A.; Vasisht, G.; Smith, R.; Krist, J. E.

2014-12-01

233

Graduate School of Pharmaceutical Sciences, Laboratory of Chemical Pharmacology Action-Potential Modulation During Axonal Conduction  

E-print Network

2010-1-31 Graduate School of Pharmaceutical Sciences, Laboratory of Chemical Pharmacology Action) Laboratory of Chemical Pharmacology Graduate School of Pharmaceutical Sciences The University of Tokyo

Imai, Hiroshi

234

Calculus+ : Cooperative Learning Experiences in a Laboratory Setting  

NSDL National Science Digital Library

This web site provides students and faculty with access to precalculus, calculus (I, II, and III), linear algebra, and differential equations computer projects. They can be simply viewed and adapted to a suitable Computer Algebra Systems software; users with Maple 8 or an earlier release installed on their computers will be able to download and modify the projects. (The site also includes an introduction to Maple and a sample interactive lesson using Maple.) The projects, part of two Minority Science and Engineering Improvement Program (MSEIP) grants, were created and class-tested at Queensborough Community College, Medgar Evers College, and Borough of Manhattan Community College of the City University of New York. They are designed for use as cooperative learning experiences in a laboratory setting and are interactive if Maple 8 or earlier releases are use. The site creators plan to add writing assignments, readings, faculty and students' exemplary work in all courses, including senior research topics in STEM areas of pure and applied mathematics.

MSEIP Team, City University of New York and State University of New York

235

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

236

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

Code of Federal Regulations, 2014 CFR

21 Food and Drugs 2 2014-04-01 2014-04-01 false...Temporary exemptions for purposes of conducting authorized food labeling experiments. 101.108 Section 101.108 Food and Drugs FOOD AND DRUG ADMINISTRATION,...

2014-04-01

237

Electrical conductivity imaging of lower extremities using MREIT: postmortem swine and in vivo human experiments.  

PubMed

Cross-sectional conductivity images of lower extremities were reconstructed using Magnetic Resonance Electrical Impedance Tomography (MREIT) techniques. Carbon-hydrogel electrodes were adopted for postmortem swine and in vivo human imaging experiments. Due to their large surface areas and good contacts on the skin, we could inject as much as 10 mA into the lower extremities of human subjects without producing a painful sensation. Using a 3T MREIT system, we first performed a series of postmortem swine experiments and produced high-resolution conductivity images of swine legs. Validating the experimental protocol for the lower extremities, we revised it for the following human experiments. After the review of the Institutional Review Board (IRB), we conducted our first MREIT experiments of human subjects using the same 3T MREIT system. Collecting magnetic flux density data inside lower extremities subject to multiple injection currents, we reconstructed cross-sectional conductivity images using the harmonic B(z) algorithm. The conductivity images very well distinguished different parts of muscles inside the lower extremities. The outermost fatty layer was clearly shown in each conductivity image. We could observe severe noise in the outer layer of the bones primarily due to the MR signal void phenomenon there. Reconstructed conductivity images indicated that the internal regions of the bones have relatively high conductivity values. Future study is desired in terms of the conductivity image reconstruction algorithm to improve the image quality. Further human imaging experiments are planned and being conducted to produce high-resolution conductivity images from different parts of the human body. PMID:19164043

Woo, Eung Je; Kim, Hyung Joong; Minhas, Atul S; Kim, Young Tae; Jeong, Woo Chul; Kwon, O

2008-01-01

238

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

239

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

240

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

241

PLANNING AND CONDUCTING COOPERATIVE OCCUPATIONAL EXPERIENCE IN OFF-FARM AGRICULTURE.  

ERIC Educational Resources Information Center

THE MAJOR OBJECTIVE OF THIS PUBLICATION IS THE ORIENTATION OF VOCATIONAL AGRICULTURE TEACHERS TO THE CONCEPTS OF PLANNING AND CONDUCTING A COOPERATIVE OCCUPATIONAL EXPERIENCE PROGRAM FOR OFF-FARM AGRICULTURE. CONTENTS INCLUDE--(1) INTRODUCTION, (2) DEVELOPING LOCAL POLICIES CONCERNING OCCUPATIONAL EXPERIENCE, (3) UTILIZING A CONSULTING COMMITTEE,…

ANDERSON, HAROLD

242

Lessons learned from 10 years experience with remote laboratories  

Microsoft Academic Search

Remote access laboratories using internet communications have been available in prototype form since the mid 1990's (Goldberg 1999, Taylor and Trevelyan 1995, Henry 2003). We started our on-line laboratory facilities at the University of Western Australia in October 1994 with the commissioning of Australia's Telerobot on the Web. This paper reviews all the principal lessons we learned since 1994 and

James TREVELYAN

243

Experience and recommendations for consolidating a Microbiology Laboratory  

Microsoft Academic Search

Hospital alliances and laboratory consolidations are taking place across the United States. The purpose of consolidation is to maximize efficiency and reduce cost. The Health Alliance of Greater Cincinnati was formed in 1994 and was completed in 1998. The alliance consists of six area hospitals. The consolidation of Alliance Laboratory Services was to be accomplished within 6 months. Bound by

Mary K. Ansara

2002-01-01

244

Hands-on laboratory Experience in Teaching-Learning Physiology.  

ERIC Educational Resources Information Center

The results of actual student participation, with organized group discussions, which show that laboratory teaching remains the premiere mechanism for teaching and learning organ-system physiology are discussed. Laboratories using a pithed frog, a turtle heart, an anesthetized rabbit, and noninvasive recordings from students during exercise are…

Randall, Walter C.; Burkholder, Timothy

1990-01-01

245

Laboratory experiment on poroelastic behavior of Berea sandstone under two-phase fluid flow condition  

NASA Astrophysics Data System (ADS)

Coupled two-phase fluid flow and deformation of Berea sandstone was discussed through laboratory experiments and numerical simulation. In the experiment, a triaxial compression apparatus with flow pipes to pass fluids through a rock sample was used. The experimental procedures were as follows. Firstly, external stresses close to hydrostatic condition were applied to a water saturated cylindrical Berea sandstone sample. Then, compressed air was infiltrated from the bottom of the sample. During the experiment, both axial and circumferential strains at half the height of the sample and volumetric discharge of water at the outlet were measured. Both strains showed sudden extensions after a few seconds, and monotonically extended thereafter. The volumetric discharge of water showed that air breakthrough occurred in around 100 seconds after the commencement of the air injection. Numerical simulations based on thermodynamically consistent constitutive equations were conducted in order to quantitatively analyze the experimental results. In a simulation in which the material was assumed to be homogeneous isotropic, the axial strain at half the height of the sample and the volumetric discharge of water at the outlet were reproduced well by using reasonable parameters, while that was not the case with the circumferential strain at half the height of the sample. On the other hand, in a simulation in which anisotropy of the material was introduced, all experimental data were reproduced well by using reasonable parameters. This result is reasonable because Berea sandstone is well known to be anisotropic under such Terzaghi effective stress condition as used in our experiment, i.e., 3.0 MPa (Hart and Wang, 1999; Hart, 2000). Our results indicate that the theory of poroelasticity for two-phase fluid system can explain the strain behavior of porous media for two-phase fluid flow observed in laboratory experiments.

Goto, H.; Aichi, M.; Tokunaga, T.; Yamamoto, H.; Ogawa, T.; Aoki, T.

2013-12-01

246

Water in cratonic lithosphere: Calibrating laboratory-determined models of electrical conductivity of mantle minerals using geophysical and petrological observations  

NASA Astrophysics Data System (ADS)

Measurements of electrical conductivity of "slightly damp" mantle minerals from different laboratories are inconsistent, requiring geophysicists to make choices between them when interpreting their electrical observations. These choices lead to dramatically different conclusions about the amount of water in the mantle, resulting in conflicting conclusions regarding rheological conditions; this impacts on our understanding of mantle convection, among other processes. To attempt to reconcile these differences, we test the laboratory-derived proton conduction models by choosing the simplest petrological scenario possible - cratonic lithosphere - from two locations in southern Africa where we have the most complete knowledge. We compare and contrast the models with field observations of electrical conductivity and of the amount of water in olivine and show that none of the models for proton conduction in olivine proposed by three laboratories are consistent with the field observations. We derive statistically model parameters of the general proton conduction equation that satisfy the observations. The pre-exponent dry proton conduction term (?0) and the activation enthalpy (?Hwet) are derived with tight bounds, and are both within the broader 2? errors of the different laboratory measurements. The two other terms used by the experimentalists, one to describe proton hopping (exponent ron pre-exponent water contentCw) and the other to describe H2O concentration-dependent activation enthalpy (term?Cw1/3 added to the activation energy), are less well defined and further field geophysical and petrological observations are required, especially in regions of higher temperature and higher water content.

Jones, Alan G.; Fullea, Javier; Evans, Rob L.; Muller, Mark R.

2012-06-01

247

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

248

Effect of tracer buoyancy on tracer experiments conducted in fractured crystalline bedrock  

Microsoft Academic Search

Tracer buoyancy has been shown to influence breakthrough from two-well tracer experiments conducted in porous media. Two-well tracer experiments are presented from fractured crystalline bedrock, in which the specific gravity of the tracer injectate varied from 1.0002 to 1.0133. Under the forced hydraulic conditions imposed, no difference in breakthrough was noted for the three experiments. These results show that even

Matthew W. Becker

2003-01-01

249

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

250

Recovery of light, non-aqueous phase liquid from porous media: laboratory experiments and model validation  

NASA Astrophysics Data System (ADS)

Laboratory experiments were conducted to measure flow of a light, non-aqueous phase liquid (LNAPL or simply "oil") in porous media. The objective of these experiments was to measure oil recovery as influenced by hysteresis, the oil-water capillary fringe, and an oil seepage face. Oil was infiltrated and allowed to redistribute across the horizontal length of a two-dimensional tank filled with medium sand. The first experiment involved oil recovery without water pumping, while the second experiment involved oil recovery with water pumping to increase the gradient toward the recovery well. Observed oil recovery compared favorably with the predictions of a numerical model (ARMOS). A dual-energy gamma radiation attenuation system monitored oil and water saturations throughout the experiments, while hydrophobic tensiometers measured the location of the air-oil table (Z ao). The experimental distribution of oil saturations suggested the need to incorporate an oil-water capillary fringe in the calculation of oil trapping in the saturated zone. Measurements of Z ao indicated that hysteresis influenced the liquid saturation-pressure relationships. When the effects of hysteresis were incorporated into the model, predicted and measured values of Z ao came into agreement, especially at early times during the recovery process. Experimental data also suggested the presence of an oil seepage face at the pumping well, but model results were not sensitive to this factor. Oil saturation measurements at later times suggested that the oil may have experienced delayed yield, an effect that was not modeled explicitly. A sensitivity analysis revealed that oil recovery predictions were most affected by horizontal hydraulic conductivity, fluid scaling parameters ?ao and ?ow, and van Genuchten ?, n, and Sm. Overall, the numerical model appeared to match measured data for oil saturation, pressure, and recovery under two sets of boundary conditions.

Waddill, Dan W.; Parker, Jack C.

1997-07-01

251

An Undergraduate Laboratory Experiment in Bioinorganic Chemistry: Ligation States of Myoglobin  

ERIC Educational Resources Information Center

Although there are numerous inorganic model systems that are readily presented as undergraduate laboratory experiments in bioinorganic chemistry, there are few examples that explore the inorganic chemistry of actual biological molecules. We present a laboratory experiment using the oxygen-binding protein myoglobin that can be easily incorporated…

Bailey, James A.

2011-01-01

252

Parallel Combinatorial Synthesis of Azo Dyes: A Combinatorial Experiment Suitable for Undergraduate Laboratories  

ERIC Educational Resources Information Center

An experiment in the parallel synthesis of azo dyes that demonstrates the concepts of structure-activity relationships and chemical diversity with vivid colors is described. It is seen that this experiment is suitable for the second-semester organic chemistry laboratory and also for the one-semester organic laboratory.

Gung, Benjamin W.; Taylor, Richard T.

2004-01-01

253

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

254

Chemical Remediation of Nickel(II) Waste: A Laboratory Experiment for General Chemistry Students  

ERIC Educational Resources Information Center

This project involved developing a method to remediate large quantities of aqueous waste from a general chemistry laboratory experiment. Aqueous Ni(II) waste from a general chemistry laboratory experiment was converted into solid nickel hydroxide hydrate with a substantial decrease in waste volume. The remediation method was developed for a…

Corcoran, K. Blake; Rood, Brian E.; Trogden, Bridget G.

2011-01-01

255

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

256

The North Pacific Acoustic Laboratory deep-water acoustic propagation experiments in the Philippine Sea.  

PubMed

A series of experiments conducted in the Philippine Sea during 2009-2011 investigated deep-water acoustic propagation and ambient noise in this oceanographically and geologically complex region: (i) the 2009 North Pacific Acoustic Laboratory (NPAL) Pilot Study/Engineering Test, (ii) the 2010-2011 NPAL Philippine Sea Experiment, and (iii) the Ocean Bottom Seismometer Augmentation of the 2010-2011 NPAL Philippine Sea Experiment. The experimental goals included (a) understanding the impacts of fronts, eddies, and internal tides on acoustic propagation, (b) determining whether acoustic methods, together with other measurements and ocean modeling, can yield estimates of the time-evolving ocean state useful for making improved acoustic predictions, (c) improving our understanding of the physics of scattering by internal waves and spice, (d) characterizing the depth dependence and temporal variability of ambient noise, and (e) understanding the relationship between the acoustic field in the water column and the seismic field in the seafloor. In these experiments, moored and ship-suspended low-frequency acoustic sources transmitted to a newly developed distributed vertical line array receiver capable of spanning the water column in the deep ocean. The acoustic transmissions and ambient noise were also recorded by a towed hydrophone array, by acoustic Seagliders, and by ocean bottom seismometers. PMID:24116529

Worcester, Peter F; Dzieciuch, Matthew A; Mercer, James A; Andrew, Rex K; Dushaw, Brian D; Baggeroer, Arthur B; Heaney, Kevin D; D'Spain, Gerald L; Colosi, John A; Stephen, Ralph A; Kemp, John N; Howe, Bruce M; Van Uffelen, Lora J; Wage, Kathleen E

2013-10-01

257

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

258

Correlation of pre-earthquake electromagnetic signals with laboratory and field rock experiments  

NASA Astrophysics Data System (ADS)

Analysis of the 2007 M5.4 Alum Rock earthquake near San José California showed that magnetic pulsations were present in large numbers and with significant amplitudes during the 2 week period leading up the event. These pulsations were 1-30 s in duration, had unusual polarities (many with only positive or only negative polarities versus both polarities), and were different than other pulsations observed over 2 years of data in that the pulse sequence was sustained over a 2 week period prior to the quake, and then disappeared shortly after the quake. A search for the underlying physics process that might explain these pulses was was undertaken, and one theory (Freund, 2002) demonstrated that charge carriers were released when various types of rocks were stressed in a laboratory environment. It was also significant that the observed charge carrier generation was transient, and resulted in pulsating current patterns. In an attempt to determine if this phenomenon occurred outside of the laboratory environment, the authors scaled up the physics experiment from a relatively small rock sample in a dry laboratory setting, to a large 7 metric tonne boulder comprised of Yosemite granite. This boulder was located in a natural, humid (above ground) setting at Bass Lake, Ca. The boulder was instrumented with two Zonge Engineering, Model ANT4 induction type magnetometers, two Trifield Air Ion Counters, a surface charge detector, a geophone, a Bruker Model EM27 Fourier Transform Infra Red (FTIR) spectrometer with Sterling cycle cooler, and various temperature sensors. The boulder was stressed over about 8 h using expanding concrete (Bustartm), until it fractured into three major pieces. The recorded data showed surface charge build up, magnetic pulsations, impulsive air conductivity changes, and acoustical cues starting about 5 h before the boulder actually broke. These magnetic and air conductivity pulse signatures resembled both the laboratory rock stressing results and the 30 October 2007 M5.4 Alum Rock earthquake field data. The second part of this paper examined other California earthquakes, prior to the Alum Rock earthquake, to see if magnetic pulsations were also present prior to those events. A search for field examples of medium earthquakes was performed to identify earthquakes where functioning magnetometers were present within 20 km, the expected detection range of the magnetometers. Two earthquakes identified in the search included the 12 August 1998 M5.1 San Juan Bautista (Hollister Ca.) earthquake and the 28 September 2004 M6.0 Parkfield Ca. earthquake. Both of these data sets were recorded using EMI Corp. Model BF4 induction magnetometers, installed in equipment owned and operated by UC Berkeley. Unfortunately, no air conductivity or IR data were available for these earthquake examples. This new analysis of old data used the raw time series data (40 samples per s), and examined the data for short duration pulsations that exceeded the normal background noise levels at each site, similar to the technique used at Alum Rock. Analysis of Hollister magnetometer, positioned 2 km from the epicenter, showed a significant increase in magnetic pulsations above quiescient threshold levels several weeks prior, and especially 2 days prior to the quake. The pattern of positive and negative pulsations observed at Hollister, were similar, but not identical to Alum Rock in that the pattern of pulsations were interspersed with Pc 1 pulsation trains, and did not start 2 weeks prior to the quake, but rather 2 days prior. The Parkfield data (magnetometer positioned 19 km from the epicenter) showed much smaller pre-earthquake pulsations, but the area had significantly higher conductivity (which attenuates the signals). More interesting was the fact that significant pulsations occurred between the aftershock sequences of quakes as the crustal stress patterns were migrating. Comparing laboratory, field experiments with a boulder, and earthquake events, striking similarities were noted in magnetic pulsations and air conductivity changes, as well

Bleier, T.; Dunson, C.; Alvarez, C.; Freund, F.; Dahlgren, R.

2010-09-01

259

A laboratory experiment for a new free-standing pupil mask coronagraph  

NASA Astrophysics Data System (ADS)

This paper presents the results of a laboratory experiment on a new free-standing pupil mask coronagraph for the direct observation of exoplanets. We focused on a binary-shaped pupil coronagraph, which is planned for installation in the next-generation infrared space telescope SPICA. Our laboratory experiments on the coronagraph were implemented inside a vacuum chamber (HOCT) to achieve greater thermal stability and to avoid air turbulence, and a contrast of 1.3×10-9 was achieved with PSF subtraction. We also carried out multi-color/broadband experiments to demonstrate that the pupil mask coronagraph works, in principle, at all wavelengths. We had previously manufactured a checker-board mask, a type of binary-shaped pupil mask, on a glass substrate, which had the disadvantages of light loss by transmission, ghosting from residual reflectance and a slightly different refractive index for each wavelength. Therefore, we developed a new free-standing mask in sheet metal, for which no substrate was needed. As a result of a He-Ne laser experiment with the free-standing mask, a contrast of 1.0×10-7 was achieved for the raw coronagraphic image. We also conducted rotated mask subtractions and numerical simulations of some errors in the mask shape and WFEs. Speckles are the major limiting factor. The free-standing mask exhibited about the same ability to improve contrast as the substrate mask. Consequently, the results of this study suggest that the binary-shaped pupil mask coronagraph can be applied to coronagraphic observations by SPICA and other telescopes.

Haze, K.; Enya, K.; Kotani, T.; Abe, L.; Nakagawa, T.; Matsuhara, H.; Sato, T.; Yamamuro, T.

2012-09-01

260

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

261

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

262

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

263

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

264

Hands-On Experience with a Turbojet Engine in the Thermal Science Laboratory Course  

NSDL National Science Digital Library

Thermal Science laboratory is the third course in the sequence of four mechanical engineering laboratories offered by the Department of Mechanical Engineering at North Carolina A&T State University. The course is one credit hour, meeting once a week for two hours. The course includes selected experiments on heat transfer and thermodynamics. In an effort to give students a combination of theoretical background and hands-on experience, a new experiment on gas turbine engine was introduced. This paper describes the experiences the students gained in this experiment. During this laboratory the students actually learned how to operate a turbojet engine, collected and analyzed the output data including thrust and efficiency, and related the experimental result to the theory learned in the thermodynamics course. This experiment complemented the thermal science laboratory course and fully integrated some aspects of thermodynamics and enhanced the students learning process.

Saad, Messiha

265

PRESS NOTICE OF ANTI-GM EVENT What: Scientists from The Sainsbury Laboratory conducting a research trial of  

E-print Network

PRESS NOTICE OF ANTI-GM EVENT What: Scientists from The Sainsbury Laboratory conducting a research trial of blight-resistant GM potatoes invited anti-GM campaigners planning a "photo shoot" in Norwich in their publicity material." Nobel Laureate Sir Paul Nurse: "Science can help ensure food security at the same time

Watson, Andrew

266

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

267

Artificial Ionospheric Heating Experiments Conducted by a Magnetosphere-Ionosphere Coupling Model  

NASA Astrophysics Data System (ADS)

This presentation discusses computational dynamics and results of artificial heating in the ionosphere. The results are then compared to experiments including a geophysical experiment conducted at the Polar Aeronomy and Radio Science Summer School (PARS) in conjunction with the High Frequency Active Auroral Research Program (HAARP) The computational model includes the following terms: ion inertia, Ohm's law (Hall term, electron pressure term, electron neutral and electron ion collisions), ionization, recombination, electron energy (heat advection, conduction, heating through ionization, ohmic heating, gravity, energy loss to neutrals and ions), as well as parameterized collisions frequencies, and a height resolved neutral atmosphere. Atmospheric conditions for the time of the experiment (plasma density, temperature, etc) are used as initial conditions. The power and frequency of the heater facility are then used to compute the heating of the ionosphere. Data processing for the experiment and model are ongoing.

Stevens, R. J.; Otto, A.; Krzykowski, M.; Solie, D.

2007-12-01

268

Mechanical instabilities observed in laboratory experiments on rocks  

Microsoft Academic Search

At a mechanical instability in our usage, the stress drops suddenly and an elastic shock is produced. Instabilities on two very different scales are observed in the laboratory: those that are clearly audible and involve a stress drop of about 10 bars or more, and those of the sort studied by Mogi, Scholz, Byerlee, and others, which can only be

W. F. Brace; J. D. Byerlee

1969-01-01

269

Laboratory Experiences in an Introduction to Natural Science Course.  

ERIC Educational Resources Information Center

Describes a two-semester course designed to meet the needs of future elementary teachers, home economists, and occupational therapists. Laboratory work includes homemade calorimeters, inclined planes, and computing. Content areas of the course include measurement, physics, chemistry, astronomy, biology, geology, and meteorology. (JN)

Barnard, Sister Marquita

1984-01-01

270

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

271

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...

272

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

273

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

274

Laboratory Scale Experiments and Numerical Modeling of Cosolvent flushing of NAPL Mixtures in Saturated Porous Media  

NASA Astrophysics Data System (ADS)

This study examines the mechanistic processes governing multiphase flow of a water-cosolvent-NAPL system in saturated porous media. Laboratory batch and column flushing experiments were conducted to determine the equilibrium properties of pure NAPL and synthetically prepared NAPL mixtures as well as NAPL recovery mechanisms for different water-ethanol contents. The effect of contact time was investigated by considering different steady and intermittent flow velocities. A modified version of multiphase flow simulator (UTCHEM) was used to compare the multiphase model simulations with the column experiment results. The effect of employing different grid geometries (1D, 2D, 3D), heterogeneity and different initial NAPL saturation configurations were also examined in the model. It is shown that the change in velocity affects the mass transfer rate between phases as well as the ultimate NAPL recovery percentage. The experiments with slow flow rate flushing of pure NAPL and the 3D UTCHEM simulations gave similar effluent concentrations and NAPL cumulative recoveries. The results were less consistent for fast non-equilibrium flow conditions. The dissolution process from the NAPL mixture into the water-ethanol flushing solutions was found to be more complex than dissolution expressions incorporated in the numerical model. The dissolution rate of individual organic compounds (namely Toluene and Benzene) from a mixture NAPL into the ethanol-water flushing solution is found not to correlate with their equilibrium solubility values.The implications of this controlled experimental and modeling study on field cosolvent remediation applications are discussed.

Agaoglu, B.; Scheytt, T. J.; Copty, N. K.

2011-12-01

275

Laboratory Animal Science Issues in the Design and Conduct of Studies with Endocrine-active Compounds  

Microsoft Academic Search

The use of rodent models for research and testing on endo- crine-active compounds necessitates an awareness of a number of laboratory animal science issues to standardize bioassay methods and facilitate reproducibility of results between laboratories. These issues are not unique to endo- crine research but are particularly important in this field due to the complexities and interdependencies of the endocrine

Jeffrey I. Everitt; Paul M. D. Foster

2004-01-01

276

An integrated laboratory method to measure and verify directional hydraulic conductivity in fine-to-medium sandy sediments.  

PubMed

The constant-head permeameter test (CHPT) is widely used in sandy samples as a standard method in the laboratory to investigate hydraulic conductivity (K). However, it neither can be used to consistently determine directional hydraulic conductivity (DHC) nor guarantee the comparability of measured K values of samples with different sizes. Therefore, this paper proposes an integrated laboratory method, called modified CHPT (MCHPT), for the efficient determination and verification of consistent DHC values in fine-to-medium sandy sediments, based on a new methodological framework. A precise and standardized procedure for preparing the experimental setup of MCHPT was conducted, based on the integrated experimental setup of CHPT and tracer tests. Moreover, a formula was yielded for the time-optimized sample saturation control. In comparison with grain size-based methods, the validity of consistent Kh and Kv values determined by MCHPT was convincing. PMID:24393110

Cai, Jialiang; Taute, Thomas; Hamann, Enrico; Schneider, Michael

2015-01-01

277

Chemistry Graduate Teaching Assistants' Experiences in Academic Laboratories and Development of a Teaching Self-image  

NASA Astrophysics Data System (ADS)

Graduate teaching assistants (GTAs) play a prominent role in chemistry laboratory instruction at research based universities. They teach almost all undergraduate chemistry laboratory courses. However, their role in laboratory instruction has often been overlooked in educational research. Interest in chemistry GTAs has been placed on training and their perceived expectations, but less attention has been paid to their experiences or their potential benefits from teaching. This work was designed to investigate GTAs' experiences in and benefits from laboratory instructional environments. This dissertation includes three related studies on GTAs' experiences teaching in general chemistry laboratories. Qualitative methods were used for each study. First, phenomenological analysis was used to explore GTAs' experiences in an expository laboratory program. Post-teaching interviews were the primary data source. GTAs experiences were described in three dimensions: doing, knowing, and transferring. Gains available to GTAs revolved around general teaching skills. However, no gains specifically related to scientific development were found in this laboratory format. Case-study methods were used to explore and illustrate ways GTAs develop a GTA self-image---the way they see themselves as instructors. Two general chemistry laboratory programs that represent two very different instructional frameworks were chosen for the context of this study. The first program used a cooperative project-based approach. The second program used weekly, verification-type activities. End of the semester interviews were collected and served as the primary data source. A follow-up case study of a new cohort of GTAs in the cooperative problem-based laboratory was undertaken to investigate changes in GTAs' self-images over the course of one semester. Pre-semester and post-semester interviews served as the primary data source. Findings suggest that GTAs' construction of their self-image is shaped through the interaction of 1) prior experiences, 2) training, 3) beliefs about the nature of knowledge, 4) beliefs about the nature of laboratory work, and 5) involvement in the laboratory setting. Further GTAs' self-images are malleable and susceptible to change through their laboratory teaching experiences. Overall, this dissertation contributes to chemistry education by providing a model useful for exploring GTAs' development of a self-image in laboratory teaching. This work may assist laboratory instructors and coordinators in reconsidering, when applicable, GTA training and support. This work also holds considerable implications for how teaching experiences are conceptualized as part of the chemistry graduate education experience. Findings suggest that appropriate teaching experiences may contribute towards better preparing graduate students for their journey in becoming scientists.

Gatlin, Todd Adam

278

A "Greenhouse Gas" Experiment for the Undergraduate Laboratory  

ERIC Educational Resources Information Center

This experiment and analysis offer an effective experience in greenhouse gas reduction. Ammoniated water is flowed counter-current to a simulated flue gas of air and CO2 in a packed column. The gaseous CO2 concentrations are measured with an on-line, non- dispersive, infrared analyzer. Column operating parameters include total gas flux, dissolved…

Gomez, Elaine; Paul, Melissa; Como, Charles; Barat, Robert

2014-01-01

279

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

280

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

281

Iron-Sulfur-Carbonyl and -Nitrosyl Complexes: A Laboratory Experiment.  

ERIC Educational Resources Information Center

Background information, materials needed, procedures used, and typical results obtained, are provided for an experiment on iron-sulfur-carbonyl and -nitrosyl complexes. The experiment involved (1) use of inert atmospheric techniques and thin-layer and flexible-column chromatography and (2) interpretation of infrared, hydrogen and carbon-13 nuclear…

Glidewell, Christopher; And Others

1985-01-01

282

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

283

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

284

Using Coupled Mesoscale Experiments and Simulations to Investigate High Burn-Up Oxide Fuel Thermal Conductivity  

NASA Astrophysics Data System (ADS)

Nuclear energy is a mature technology with a small carbon footprint. However, work is needed to make current reactor technology more accident tolerant and to allow reactor fuel to be burned in a reactor for longer periods of time. Optimizing the reactor fuel performance is essentially a materials science problem. The current understanding of fuel microstructure have been limited by the difficulty in studying the structure and chemistry of irradiated fuel samples at the mesoscale. Here, we take advantage of recent advances in experimental capabilities to characterize the microstructure in 3D of irradiated mixed oxide (MOX) fuel taken from two radial positions in the fuel pellet. We also reconstruct these microstructures using Idaho National Laboratory's MARMOT code and calculate the impact of microstructure heterogeneities on the effective thermal conductivity using mesoscale heat conduction simulations. The thermal conductivities of both samples are higher than the bulk MOX thermal conductivity because of the formation of metallic precipitates and because we do not currently consider phonon scattering due to defects smaller than the experimental resolution. We also used the results to investigate the accuracy of simple thermal conductivity approximations and equations to convert 2D thermal conductivities to 3D. It was found that these approximations struggle to predict the complex thermal transport interactions between metal precipitates and voids.

Teague, Melissa C.; Fromm, Bradley S.; Tonks, Michael R.; Field, David P.

2014-12-01

285

Touring the Tomato: A Suite of Chemistry Laboratory Experiments.  

PubMed

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. PMID:23526490

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

2013-03-12

286

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

287

Undergraduate Experiment on Low-Temperature Dependence of the Conductivity of Copper Wire  

Microsoft Academic Search

A simple experiment is described that permits advanced undergraduates to investigate the temperature dependence of electrical conductivity in copper wire down to liquid helium temperatures. At temperatures below 40° K the experimental results approach the T5 behavior expected from quantum mechanical calculations. At temperatures below 8° K a constant, nonvanishing resistance is found. The apparatus uses a nested Dewar system

R. M. Dasheiff; W. S. Risk

1972-01-01

288

Teaching and Learning Responsible Research Conduct: Influences of Prior Experiences on Acceptance of New Ideas  

Microsoft Academic Search

Despite requirements for Responsible Conduct of Research (RCR) training, little is known about how much this training actually influences the thinking and behaviors of participants. Interview-based qualitative research methods were used to study the reactions of Ph.D. students and postdoctoral fellows to what was taught in an RCR course. For trainees with limited prior RCR experience, or who agreed with

RICHARD MCGEE; JULKA ALMQUIST; JILL L. KELLER; STEVEN J. JACOBSEN

2008-01-01

289

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

290

First observations of runaway breakdown phenomenon in Laboratory experiments  

NASA Astrophysics Data System (ADS)

Microwave electron cyclotron resonance discharge in air is studied in a time-varying magnetic mirror trap. The obtained experimental data demonstrate a rapid increase in the number of fast electrons with wide energy spectrum (1-300 keV). It is followed by strong flashes of ? photons and associated secondary optic emission. The experimental results are interpreted as the first observation in a laboratory of the runaway breakdown phenomenon, which plays a significant role in a thunderstorm atmosphere.

Gurevich, A. V.; Sergeichev, K. F.; Sychov, I. A.; Roussel-Dupre, R.; Zybin, K. P.

1999-09-01

291

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

292

Reflectance Experiment Laboratory (RELAB) Description and User's Manual  

NASA Technical Reports Server (NTRS)

Spectroscopic data acquired in the laboratory provide the interpretive foundation upon which compositional information about unexplored or unsampled planetary surfaces is derived from remotely obtained reflectance spectra. The RELAB is supported by NASA as a multi-user spectroscopy facility, and laboratory time can be made available at no charge to investigators who are in funded NASA programs. RELAB has two operational spectrometers available to NASA scientists: 1) a near- ultraviolet, visible, and near-infrared bidirectional spectrometer and 2) a near- and mid- infrared FT-IR spectrometer. The overall purpose of the design and operation of the RELAB bidirectional spectrometer is to obtain high precision, high spectral resolution, bidirectional reflectance spectra of earth and planetary materials. One of the key elements of its design is the ability to measure samples using viewing geometries specified by the user. This allows investigators to simulate, under laboratory conditions, reflectance spectra obtained remotely (i.e., with spaceborne, telescopic, and airborne systems) as well as to investigate geometry dependent reflectance properties of geologic materials. The Nicolet 740 FT-IR spectrometer currently operates in reflectance mode from 0.9 to 25 Fm. Use and scheduling of the RELAB is monitored by a 4-member advisory committee. NASA investigators should direct inquiries to the Science Manager or RELAB Operator.

Pieters, Carle M.; Hiroi, Takahiro; Pratt, Steve F.; Patterson, Bill

2004-01-01

293

Responses to Anomalous Data Obtained from Repeatable Experiments in the Laboratory  

ERIC Educational Resources Information Center

The purpose of this study was to investigate the possible responses to anomalous data obtained from experiments that are repeatable by carrying out additional or alternative experiments in the laboratory. Based on an analysis of responses from scientists to anomalous data taken from identification experiments on the Vinland Map, it was assumed…

Lin, Jer-Yann

2007-01-01

294

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

295

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...

296

Electrical conductivity in a partially molten lower crust from laboratory measurements on xenoliths (El Hoyazo, SE Spain)  

NASA Astrophysics Data System (ADS)

The presence of High Conductive Zones (HCZs) within the lower crust is explained by several mechanisms involving phases as graphite, brines and partial melts, which enhance the conductivity when inteconnected over large distances. In the Internal Betics (Southern Spain) the anomalous HCZ imaged at the bottom of a thinned lower crust (Pous et al., 1999) is combined with low seismic velocities and high heat flow values (Carbonell et al., 1998) supporting the hypothesis that partial melts are present at depths. This is further confirmed by the recovery of restitic lower crustal xenoliths retaining evidence of partial melting (Zeck, 1968). The xenolith also contain up to 2 wt% of graphite which may contribute to the conductivity enhancement. The present study is focused on the electrical conductivity at high pressure and temperature of four garnet-biotite-sillimanite metapelitic xenoliths collected from the Neogene dacites of El Hoyazo (SE Spain). The paragenesis is represented by garnet + biotite + sillimanite + plagioclase ± cordierite coexisting with graphite and widespread rhyolitic melt as inclusions and interstitial glass (~10 wt%) (Cesare & Gómez-Pugnaire, 2001). The assemblage developed during regional anatexis at 850-900°C and 500 - 700 MPa (Cesare et al., 1997) and melt was frozen-in during fast uplift. In order to discriminate the contibution of graphite and melt, assess the effect of their geometrical distribution and infer the influence of the glass rheology to the electrical conductivity, experiments were performed in two gas apparata at sealed and unsealed conditions. In unsealed runs, in fact, the porosity remains open which prevents graphite reconnection. The sealed experiments were conducted in a Paterson Apparatus up to 680°C and 840°C at 100 MPa and to 900°C at 300 MPa, the unsealed ones in an internally heated gas apparatus (IHPV) with Ar as pressure medium up to 950°C and 400 MPa. For each sample three mutually orthogonal cores (X, Y, Z) were drilled parallel to the macroscopic fabric elements to determine the electrical anisotropy: X parallel to lineation and Z normal to foliation. Two electrodes were placed on the top and the bottom surfaces of the cores in a two pole arrangement in both the Paterson apparatus and the HIPV. In the Paterson apparatus, Nickel electrodes were used together with iron jackets to control the oxygen fugacity and temperature was monitored with one K-type thermocouple soldered on one of the two electrodes. In the IHPV two Platinum discs were connected to Pt and PtRh wires as S-type thermocouples. An authomated impedance spectrometer was used to collect the resistivity values in the range 1-105 Hz. The Arrhenius plot of the Logarithmic specific conductivity versus the reciprocal absolute temperature, evidence that the electrical properties are remarkably similar in unsealed and sealed runs up to 700°C and linear above 400°C with an activation energy Ea =0.340 ÷ 0.561 eV. At 700°C, in unsealed experiments Ea increases to 1.03 ÷ 1.34 eV and a single impedance arc is observed at every temperature. In sealed experiments, the increment of Ea at 700°C is higher, up to 1.64 eV, and two impedance arcs (along direction X) or three (along Y) are observed. Melting occurs at T>800°C with the production of very tiny spinel + biotite + plagioclase + melt. At 700°C a phase interconnection is achieved which may be related to the glass transition temperature Te of the initial glass. The laboratory measurements are consistent with the magnetotelluric soundings at temperature of 800-880°C and compatible with the hypothesis that partial melts are present in the Alborán lower crust. This temperature value is important to constraint the actual geotherm in the area. REFERENCES Carbonell R., Sallarés V., Puos J., Dañobeitia J.J., Queralt P., Ledo J.J. and Dueñas G. Tectonophysics, 288: 137-152, 1998 Cesare B., Salvioli Mariani E. and Venturelli G., Mineral. Magaz. 61 (1): 15-27, 1997 Cesare B. & Gómez-Pugnaire M. T., Phys. Chem. Earth (A), 26 (4-5): 255-260, 2001 Holtz

Ferri, F.; Gibért, B.; Violay, M.; Schilling, F. R.; Cesare, B.

2009-04-01

297

Do stable isotopes reflect nutritional stress? Results from a laboratory experiment on song sparrows.  

PubMed

Stable isotope analysis is an increasingly valuable tool in ecological studies and shows promise as a measure of nutritional stress in wild animals. Thus far, however, the only studies on endotherms that have conclusively shown changes in delta(15)N and delta(13)C values in response to nutritional stress were conducted on fasting animals and animals growing under extreme levels of food restriction. We conducted a laboratory experiment to test whether delta(15)N and delta(13)C values provide a general index of nutritional stress. We compared the isotopic composition of whole blood, liver, muscle and feathers between two groups of juvenile song sparrows (Melospiza melodia) hand-reared in captivity under identical conditions except for feeding regime. To verify that our experimental treatment induced a biologically meaningful level of nutritional stress, we simultaneously measured the effects on physiology, growth and development at multiple scales. While food-restricted birds were physiologically stressed, physically smaller, and showed poorer growth and brain development compared to ad libitum-fed birds, there was no effect of feeding regime on either delta(15)N or delta(13)C values in any tissue. Instead of a continuum where the level of change in (15)N or (13)C contents corresponds to the level of nutritional stress, we suggest there may be a threshold level of nutritional stress below which such isotopic changes are likely to be negligible. PMID:17102993

Kempster, Bethany; Zanette, Liana; Longstaffe, Fred J; MacDougall-Shackleton, Scott A; Wingfield, John C; Clinchy, Michael

2007-03-01

298

Absorption spectroscopy of a laboratory photoionized plasma experiment at Z  

SciTech Connect

The Z facility at the Sandia National Laboratories is the most energetic terrestrial source of X-rays and provides an opportunity to produce photoionized plasmas in a relatively well characterised radiation environment. We use detailed atomic-kinetic and spectral simulations to analyze the absorption spectra of a photoionized neon plasma driven by the x-ray flux from a z-pinch. The broadband x-ray flux both photoionizes and backlights the plasma. In particular, we focus on extracting the charge state distribution of the plasma and the characteristics of the radiation field driving the plasma in order to estimate the ionisation parameter.

Hall, I. M.; Durmaz, T.; Mancini, R. C. [Physics Department, University of Nevada, Reno, Nevada 89557 (United States)] [Physics Department, University of Nevada, Reno, Nevada 89557 (United States); Bailey, J. E.; Rochau, G. A. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Golovkin, I. E.; MacFarlane, J. J. [Prism Computational Sciences, Madison, Wisconsin 53711 (United States)] [Prism Computational Sciences, Madison, Wisconsin 53711 (United States)

2014-03-15

299

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

300

Zero-gravity atmospheric Cloud Physics Experiment Laboratory; Programmatics report  

NASA Technical Reports Server (NTRS)

The programmatics effort included comprehensive analyses in four major areas: (1) work breakdown structure, (2) schedules, (3) costs, and (4) supporting research and technology. These analyses are discussed in detail in the following sections which identify and define the laboratory project development schedule, cost estimates, funding distributions and supporting research and technology requirements. All programmatics analyses are correlated among themselves and with the technical analyses by means of the work breakdown structure which serves as a common framework for program definition. In addition, the programmatic analyses reflect the results of analyses and plans for reliability, safety, test, and maintenance and refurbishment.

1974-01-01

301

Absorption spectroscopy of a laboratory photoionized plasma experiment at Z  

NASA Astrophysics Data System (ADS)

The Z facility at the Sandia National Laboratories is the most energetic terrestrial source of X-rays and provides an opportunity to produce photoionized plasmas in a relatively well characterised radiation environment. We use detailed atomic-kinetic and spectral simulations to analyze the absorption spectra of a photoionized neon plasma driven by the x-ray flux from a z-pinch. The broadband x-ray flux both photoionizes and backlights the plasma. In particular, we focus on extracting the charge state distribution of the plasma and the characteristics of the radiation field driving the plasma in order to estimate the ionisation parameter.

Hall, I. M.; Durmaz, T.; Mancini, R. C.; Bailey, J. E.; Rochau, G. A.; Golovkin, I. E.; MacFarlane, J. J.

2014-03-01

302

Mechanical Properties of Asteroid Materials: Clues from Analysis of Spacecraft Images and Results from Laboratory Experiments  

NASA Astrophysics Data System (ADS)

We use analysis of spacecraft imagery to measure the coefficient of restitution of regolith and results from laboratory experiments on meteorites and cohesive powders to measure the properties of asteroid materials.

Durda, D. D.

2015-01-01

303

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

304

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

305

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

306

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

307

An Analysis of High School Students' Perceptions and Academic Performance in Laboratory Experiences  

ERIC Educational Resources Information Center

This research study is an investigation of student-laboratory (i.e., lab) learning based on students' perceptions of experiences using questionnaire data and evidence of their science-laboratory performance based on paper-and-pencil assessments using Maryland-mandated criteria, Montgomery County Public Schools (MCPS) criteria, and published…

Mirchin, Robert Douglas

2012-01-01

308

Combustion and Energy Transfer Experiments: A Laboratory Model for Linking Core Concepts Across the Science Curriculum  

NSDL National Science Digital Library

Core concepts can be integrated throughout lower-division science and engineering courses by using a series of related, cross-referenced laboratory experiments. Starting with butane combustion in chemistry, we expanded the underlying core concepts of energy transfer into laboratories designed for biology, physics, and engineering.

David W. Brown

2007-01-01

309

Combustion and Energy Transfer Experiments: A Laboratory Model for Linking Core Concepts across the Science Curriculum  

ERIC Educational Resources Information Center

Core concepts can be integrated throughout lower-division science and engineering courses by using a series of related, cross-referenced laboratory experiments. Starting with butane combustion in chemistry, the authors expanded the underlying core concepts of energy transfer into laboratories designed for biology, physics, and engineering. This…

Barreto, Jose C.; Dubetz, Terry A.; Schmidt, Diane L.; Isern, Sharon; Beatty, Thomas; Brown, David W.; Gillman, Edward; Alberte, Randall S.; Egiebor, Nosa O.

2007-01-01

310

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

311

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

312

The Heavy Photon Search Experiment at Jefferson Laboratory  

NASA Astrophysics Data System (ADS)

The Heavy Photon Search (HPS) is a new experiment at Jefferson Lab that will search for massive U(1) vector bosons (also known as heavy photons, dark photons, or A') of mass 20--1000 MeV that couple to electric charge with relative coupling ?'/? of 10-5--10-10. The HPS experiment is designed to produce heavy photons by electron scattering off a fixed target, and detect them using two decay channels (e^+e^- or ^amp;+^amp;- pairs) and two signatures (invariant mass resonance and displaced decay vertex). The detector is a compact, large-acceptance forward spectrometer comprising a silicon microstrip tracker for momentum measurement and vertexing, an electromagnetic calorimeter for triggering on e^+e^-, and a muon detector for triggering on ^amp;+^amp;-. This talk will cover the motivations for heavy photons and give an overview of the HPS experiment.

Uemura, Sho

2013-04-01

313

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.

314

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

315

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

316

Laboratory evaluation of the constant rate of strain and constant head techniques for measurement of the hydraulic conductivity of fine grained soils  

E-print Network

This thesis evaluates the constant rate of strain and constant head techniques for measurement of the hydraulic conductivity of fine grained soils. A laboratory program compares hydraulic conductivity measurements made ...

Adams, Amy Lynn

2011-01-01

317

Artist rendition of the planned Space Experiment Research and Processing Laboratory  

NASA Technical Reports Server (NTRS)

The preliminary design for the Space Experiment Research and Processing Laboratory (SERPL) at Kennedy Space Center is shown in this artist's rendition. 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

318

Effect of Surface Conductivity on Magnetosphere Formation in Experiments with Laser Plasma flow over a Magnetic Dipole  

NASA Astrophysics Data System (ADS)

This paper presents the results of laboratory experiments with laser plasma flow around a magnetic dipole which model the extreme compression of the Earth? magnetosphere by the plasma generated by high-power coronal mass ejections. Data on the formation of an artificial magnetosphere, the boundary-layer structure, and the size of the magnetosphere as a function of the magnetic moment are given. It is shown that in the presence of a conducting dipole shell modeling the ionosphere, conditions are created for the flow of intense longitudinal currents in the polar regions. It is established that the longitudinal currents have little effect on the position of the plasma stagnation point and the transition layer but make a significant contribution to the disturbance of the magnetic field in the magnetosphere.

Antonov, V. M.; Boyarintsev, E. L.; Zakharov, Yu. P.; Melekhov, A. V.; Posukh, V. G.; Ponomarenko, A. G.; Shaikhislamov, I. F.

2010-09-01

319

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

320

RELATIONSHIP OF LABORATORY AND FIELD DETERMINED HYDRAULIC CONDUCTIVITY IN COMPACTED CLAY LAYER  

EPA Science Inventory

An evaluation of the hydraulic conductivity of a compacted clay liner was conducted on an extensively instrumented field-scale research facility. Infiltration and seepage were measured at 250 evenly spaced points. patial variability of soil, water content, and density was high ev...

321

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

322

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

323

Laboratory Experiments with Okapi: Participation in the TREC Programme.  

ERIC Educational Resources Information Center

Summarizes the development of information retrieval evaluation ideas, describes the design of the TREC (Text Retrieval Conference) experiments, and discusses the Okapi team's participation in TREC. Highlights include the Cranfield projects that tested the principles of information retrieval system design, test collections, weighting functions,…

Robertson, S. E.; And Others

1997-01-01

324

Millikan Oil-Drop Experiment in the Introductory Laboratory  

ERIC Educational Resources Information Center

Discusses a simplified Millikan oil-drop experiment which emphasizes the enplanation of basic concepts in mechanics and electrostatics, the use of home-made apparatus, the request for an individual's observation of his own drop, and the application of statistical analysis in data interpretation. (CC)

Heald, Mark A.

1974-01-01

325

Beauty, gender and stereotypes: Evidence from laboratory experiments  

Microsoft Academic Search

The existence of a beauty premium in the labor market and the male–female wage gap suggests that appearance can matter in the real world. We explore beauty and gender in a public goods experiment and find similar effects. We find a beauty premium, even though beautiful people contribute, on average, no more or less than others. The beauty premium, however,

James Andreoni; Ragan Petrie

2008-01-01

326

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

327

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

328

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

329

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

330

A Laboratory Experiment on How to Create Dimensionless Correlations  

ERIC Educational Resources Information Center

An experiment is described that illustrates how chemical engineering correlations are created. Balls of different diameters and different specific gravities (all less than one) are dropped from several heights into a pool of water, and the maximum depth reached by the ball is measured. This data is used to estimate the coefficients for a…

Edwards, Robert V.

2010-01-01

331

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

332

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

333

Computational/experimental basis for conducting alkane droplet combustion experiments on space-based-platforms  

NASA Technical Reports Server (NTRS)

An analysis is conducted of the requirement for the conduct of spherically symmetric droplet-combustion experiments on space platforms, on the basis of a novel time-dependent computational droplet combustion model that allows the time- and temperature-dependent transport characteristics to be incorporated. While at low oxygen indices the droplet burning extinction becomes a strong function of oxygen index, it becomes a weaker function at higher oxygen index values. The oxygen index that separates these two ranges are dependent on the diluent, being higher for He and lower for N.

Choi, Mun Y.; Cho, Seog Y.; Dryer, Frederick L.; Haggard, John B., Jr.

1992-01-01

334

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

335

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

336

Radiative Transfer Theory Verified by Controlled Laboratory Experiments  

NASA Technical Reports Server (NTRS)

We report the results of high-accuracy controlled laboratory measurements of the Stokes reflection matrix for suspensions of submicrometer-sized latex particles in water and compare them with the results of a numerically exact computer solution of the vector radiative transfer equation (VRTE). The quantitative performance of the VRTE is monitored by increasing the volume packing density of the latex particles from 2 to 10. Our results indicate that the VRTE can be applied safely to random particulate media with packing densities up to 2. VRTE results for packing densities of the order of 5 should be taken with caution, whereas the polarized bidirectional reflectivity of suspensions with larger packing densities cannot be accurately predicted. We demonstrate that a simple modification of the phase matrix entering the VRTE based on the so-called static structure factor can be a promising remedy that deserves further examination.

Mishchenko, Michael I.; Goldstein, Dennis H.; Chowdhary, Jacek; Lompado, Arthur

2013-01-01

337

Improved laboratory diagnosis of tuberculosis--the Indian experience.  

PubMed

Tuberculosis (TB) is the leading cause of death worldwide attributable to a single infectious disease agent. India has more new TB cases annually than any other country. In 2008, India accounted for a fifth of the estimated 9.4 million TB cases globally. There is an overwhelming need for improving TB diagnostics in India through the use of cost effective, patient-friendly methods appropriate to different tiers of the country health system. Substantial progress has been made in India in the field of TB diagnosis and serious efforts have been made to herald the development of diagnostic tests for pulmonary TB, extra pulmonary TB and MDR-TB. Diverse approaches have been attempted towards improving smear microscopy, rapid culture and for differentiation between the Mycobacterium tuberculosis complex and non-tuberculous mycobacteria. Several laboratories have developed in-house PCR assays for diagnosing TB with high accuracy. Approaches for distinguishing M. tuberculosis and/or Mycobacterium bovis infection and disseminated Mycobacterium avium complex infection in HIV-AIDS patients have also been described. Serological tests to detect antigens or antibodies to M. tuberculosis specific components by using cocktails of Excretory/Secretory protein antigens, Ag85 complex antigens, Hsp 65 antigen, RD1 antigens and Rapid Reverse Line Blot Hybridization assays to detect MDR-TB (mutations to rifampicin, isoniazid and streptomycin) have also been developed. Other methods like measurement of adenosine deaminase activity and use of luciferase reporter phages have also been explored for TB diagnosis. These advances in the Indian context are detailed in the present chapter. The validation and application of these methods in laboratory and public health settings is likely to result in improved TB diagnosis and contribute to effective disease management in India. PMID:21764383

Haldar, Sagarika; Bose, Mridula; Chakrabarti, Parul; Daginawala, Hatim F; Harinath, B C; Kashyap, Rajpal S; Kulkarni, Savita; Majumdar, Anindita; Prasad, H Krishna; Rodrigues, Camilla; Srivastava, Ranjana; Taori, Girdhar M; Varma-Basil, Mandira; Tyagi, Jaya S

2011-09-01

338

Annotated List of Laboratory Experiments in Chemistry from the Journal of Chemical Education. Second Edition, 1957-1984.  

ERIC Educational Resources Information Center

This document is the second edition of the Annotated List of Laboratory Experiments in Chemistry first published in 1980. All entries in the Journal of Chemical Education describing laboratory experiments in chemistry or laboratory descriptions suitable for student experiments or projects, for the years 1957-1984 inclusive, have been listed and…

Allen, C. B.; And Others

339

Laser fusion experiments, facilities and diagnostics at Lawrence Livermore Laboratory  

SciTech Connect

The progress of the LLL Laser Fusion Program to achieve high gain thermonuclear micro-explosions is discussed. Many experiments have been successfully performed and diagnosed using the large complex, 10-beam, 30 TW Shiva laser system. A 400 kJ design of the 20-beam Nova laser has been completed. The construction of the first phase of this facility has begun. New diagnostic instruments are described which provide one with new and improved resolution, information on laser absorption and scattering, thermal energy flow, suprathermal electrons and their effects, and final fuel conditions. Measurements were made on the absorption and Brillouin scattering for target irradiations at both 1.064 ..mu..m and 532 nm. These measurements confirm the expected increased absorption and reduced scattering at the shorter wavelength. Implosion experiments have been performed which have produced final fuel densities over the range of 10x to 100x liquid DT density.

Ahlstrom, H.G.

1980-02-01

340

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

341

Update on poultry viral diseases research conducted at Southeast Poultry Research Laboratory  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Southeast Poultry Research Laboratory does intramural research for the United States Department of Agriculture on several poultry diseases. Following are some of the research accomplishments from last year. In the area of influenza research, we demonstrated that laying turkey hens inoculated wit...

342

DEVELOPMENT OF A SYSTEM FOR CONDUCTING INTER-LABORATORY TESTS FOR WATER QUALITY AND EFFLUENT MEASUREMENTS  

EPA Science Inventory

FMC Corporation has Developed a system for evaluating water pollution data and the laboratories which produce these data. The system consists of a plan for the design and implementation of an interlaboratory test program. A pilot test program was included to evaluate and to verif...

343

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

344

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

345

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

346

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

347

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

348

Relation between creep compliance and elastic modulus in organic-rich shales observed through laboratory experiments.  

NASA Astrophysics Data System (ADS)

We studied the ductile creep behavior of organic-rich shales from shale gas reservoirs in North America through laboratory triaxial experiments to better understand controls on the physical behavior of these rocks over time and the effect of creep on other rock properties. Laboratory experiments conducted at room-temperature conditions show that creep deformation observed at in-situ differential stress conditions is approximately linear with the applied differential pressure. The creep behavior is also anisotropic such that creep occurs more in the bedding-perpendicular direction than in the bedding-parallel direction. The reduction in sample volume during creep suggests that the creep is accommodated by a small amount of pore compaction occurring in the clay-aggregates and/or the relatively porous kerogen in the rock. Thus, the tendency to creep (creep compliance) is generally observed to increases with clay and kerogen volume. However, the strongest correlation is found between creep compliance and Young's modulus. A strong negative correlation between creep compliance and elastic Young's modulus exists regardless of the sample orientation and despite the wide range of sample mineralogy (5-50% clay, 5-60% quartz-feldspar-pyrite, 0-80% carbonates). This correlation is quite interesting as inelastic creep and elastic stiffness depend on somewhat different physical attributes. We attempt to quantitatively explain the correlation between creep behavior and elastic stiffness by appealing to a stress-partitioning that occurs between the soft components (clay and kerogen) and stiff components (quartz, feldspar, pyrite, carbonates) of the shale rock. First, the stress-partitioning occurring within the soft and stiff components is quantified based on the rock composition, elastic properties of the individual components, and the overall average Young's modulus of the rock. By combining the stress-partitioning behavior with knowledge that the creep behavior is linear against the applied stress, we forward calculate the creep compliance of the whole rock. Results show that when creep is linear against stress, a unique relation between creep compliance and elastic modulus can be established for rocks with similar mineral assemblages, consistent with our laboratory results. Thus, our results provide insights into how creep behaviors of poly-mineralic rocks can be re-constructed from the creep properties of the individual phases composing the rock.

Sone, Hiroki; Zoback, Mark

2013-04-01

349

Intern experience with the Environmental Laboratory of the U.S. Army Engineer Waterways Experiment Station: an internship report  

E-print Network

as quality control monitor, providing expert testimony, assisting with portions of Environmental Impact Statements, and advising on various operational problems encountered during projects. Topics are varied and the only real criteria for requesting... with the Environmental Laboratory at the U.S. Army Engineer Waterways Experi? ment Station (WES), Vicksburg, Mississippi. A statement of objectives was prepared prior to the internship to provide guidance for the experi? ence and to allow for a meaningful assessment...

Truitt, Clifford Lee, 1948-

2013-03-13

350

Laboratory experiment on the use of pulse code modulation to transmit audio digitally  

Microsoft Academic Search

In this paper we present a practical laboratory experiment intended for undergraduate and graduate Electronic Engineering courses on Digital Communications Systems. The main objective of the experiment is to design and implement the electronics of a baseband system that uses pulse code modulation (PCM) to transmit audio signals digitally.

S. Rodriguez; A. Ayala; B. R. Mendoza; O. Gonzalez

2012-01-01

351

Size Exclusion Chromatography: An Experiment for High School and Community College Chemistry and Biotechnology Laboratory Programs  

ERIC Educational Resources Information Center

A simple multiday laboratory exercise suitable for use in a high school or community college chemistry course or a biotechnology advanced placement biology course is described. In this experiment students gain experience in the use of column chromatography as a tool for the separation and characterization of biomolecules, thus expanding their…

Brunauer, Linda S.; Davis, Kathryn K.

2008-01-01

352

A fuzzy logic control of electro-hydraulic systems laboratory experiment in mechatronics education  

Microsoft Academic Search

This paper presents a new laboratory experiment, which was developed to teach teacher training in mechatronics engineering students at King Mongkut's University of Technology North Bangkok (KMUTNB). The main issues regarding fuzzy logic control (FLC) for controls the electro-hydraulic systems (EHS), is discussed. In this experiment consider the use of Nation Instruments' LabVIEW™ with the associated data acquisition (DAQ) and

Pornjit Pratumsuwan; Siripun Thongchai; Surapun Tansriwong

2010-01-01

353

Lysozyme Thermal Denaturation and Self-Interaction: Four Integrated Thermodynamic Experiments for the Physical Chemistry Laboratory  

ERIC Educational Resources Information Center

As part of an effort to infuse our physical chemistry laboratory with biologically relevant, investigative experiments, we detail four integrated thermodynamic experiments that characterize the denaturation (or unfolding) and self-interaction of hen egg white lysozyme as a function of pH and ionic strength. Students first use Protein Explorer to…

Schwinefus, Jeffrey J.; Schaefle, Nathaniel J.; Muth, Gregory W.; Miessler, Gary L.; Clark, Christopher A.

2008-01-01

354

Thermodynamic Exploration of Eosin-Lysozyme Binding: A Physical Chemistry and Biochemistry Laboratory Experiment  

ERIC Educational Resources Information Center

We developed a modular pair of experiments for use in the undergraduate physical chemistry and biochemistry laboratories. Both experiments examine the thermodynamics of the binding of a small molecule, eosin Y, to the protein lysozyme. The assay for binding is the quenching of lysozyme fluorescence by eosin through resonant energy transfer. In…

Huisman, Andrew J.; Hartsell, Lydia R.; Krueger, Brent P.; Pikaart, Michael J.

2010-01-01

355

Laboratory Experiments No 5: Measuring PM2.5 Composition Purpose of Lab 5  

E-print Network

1 Laboratory Experiments No 5: Measuring PM2.5 Composition Purpose of Lab 5: This experiment + , K+ , Mg2+ , Ca2+ ) and carbonaceous (TC, OC and EC) chemical components comprising PM2.5 ambient is a PM2.5 cut cyclone that requires a flow rate near 16.7 L/min. A denuder is placed just upstream

Weber, Rodney

356

Dark matter searches with NaI scintillators in the Canfranc underground laboratory: ANAIS experiment  

NASA Astrophysics Data System (ADS)

A large mass dark matter search experiment with NaI scintillators at the Canfranc Underground Laboratory is underway. A 10.7 kg prototype with improved light collection efficiency and special low-background improvements has been tested and started taking data underground in summer 2005. Preliminary results and prospects for the experiment are presented.

Amaré, J.; Beltrán, B.; Carmona, J. M.; Cebrián, S.; García, E.; Gómez, H.; Irastorza, I. G.; Luzón, G.; Martínez, M.; Morales, J.; Ortiz de Solórzano, A.; Pobes, C.; Puimedón, J.; Rodríguez, A.; Ruz, J.; Sarsa, M. L.; Torres, L.; Villar, J. A.

2006-05-01

357

Dark matter searches with NaI scintillators in the Canfranc underground laboratory: ANAIS experiment  

Microsoft Academic Search

A large mass dark matter search experiment with NaI scintillators at the Canfranc Underground Laboratory is underway. A 10.7 kg prototype with improved light collection efficiency and special low-background improvements has been tested and started taking data underground in summer 2005. Preliminary results and prospects for the experiment are presented.

J. Amaré; B. Beltrán; J. M. Carmona; S. Cebrián; E. García; H. Gómez; I. G. Irastorza; G. Luzón; M. Martínez; J. Morales; A. Ortiz de Solórzano; C. Pobes; J. Puimedón; A. Rodríguez; J. Ruz; M. L. Sarsa; L. Torres; J. A. Villar

2006-01-01

358

Computation of Chemical Shifts for Paramagnetic Molecules: A Laboratory Experiment for the Undergraduate Curriculum  

ERIC Educational Resources Information Center

A computational experiment investigating the [superscript 1]H and [superscript 13]C nuclear magnetic resonance (NMR) chemical shifts of molecules with unpaired electrons has been developed and implemented. This experiment is appropriate for an upper-level undergraduate laboratory course in computational, physical, or inorganic chemistry. The…

Pritchard, Benjamin P.; Simpson, Scott; Zurek, Eva; Autschbach, Jochen

2014-01-01

359

Virtualisation of Engineering Discipline Experiments for an Internet-Based Remote Laboratory  

ERIC Educational Resources Information Center

A comprehensive survey on the Internet based virtualisation of experiments is presented, covering several individual as well as collaborative efforts in various engineering disciplines. From this survey it could be concluded that there is a pressing need to develop full-fledged remote laboratory experiments for integrated directly into engineering…

Tiwari, Rajiv; Singh, Khilawan

2011-01-01

360

Designing an Acoustic Suspension Speaker System in the General Physics Laboratory: A Divergent experiment  

ERIC Educational Resources Information Center

Describes a student laboratory project involving the design of an "acoustic suspension speaker system. The characteristics of the loudspeaker used are measured as an extension of the inertia-balance experiment. The experiment may be extended to a study of Stelmholtz resonators, coupled oscillators, electromagnetic forces, thermodynamics and…

Horton, Philip B.

1969-01-01

361

An Enzymatic Clinical Chemistry Laboratory Experiment Incorporating an Introduction to Mathematical Method Comparison Techniques  

ERIC Educational Resources Information Center

An enzymatic laboratory experiment based on the analysis of serum is described that is suitable for students of clinical chemistry. The experiment incorporates an introduction to mathematical method-comparison techniques in which three different clinical glucose analysis methods are compared using linear regression and Bland-Altman difference…

Duxbury, Mark

2004-01-01

362

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

363

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

364

Examination of a Reaction Mechanism by Polarimetry: An Experiment for the Undergraduate Organic Chemistry Laboratory  

NASA Astrophysics Data System (ADS)

An undergraduate Organic chemistry laboratory experiment involving the use of polarimetry to determine a reaction mechanism is described. The experiment has been shown to be successful with chiral mandelic acid and POCl3 and with chiral lactic acid and HBr. The substitution mechanisms of these reactions proceed with 1% and 38% SN2 character respectively.

Mosher, Michael D.; Kelly, Chad O.; Mosher, Melvyn W.

1996-06-01

365

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

ERIC Educational Resources Information Center

Cross-disciplinary (CD) learning experiences benefit student understanding of concepts and curriculum by offering opportunities to explore topics from the perspectives of alternate fields of study. This report involves a qualitative evaluation of CD health sciences undergraduate laboratory experiences in which concepts and students from two…

Mulligan, Gregory; Taylor, Nichole; Glen, Mary; Tomlin, Dona; Gaul, Catherine A.

2011-01-01

366

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

367

Development of a Jet Engine Experiment for the Energy Systems Laboratory  

Microsoft Academic Search

Recently, a jet engine experiment was added to the Energy Systems Laboratory at Kettering University (formerly GMI). The educational objectives of this experiment are: to familiarize the students with the operation of a turbojet engine, the theory behind the thermodynamic processes involved, and the linear momentum equation; to determine theoretical and measured engine thrust and the efficiencies of the compressor,

A. Pourmovahed; C. M. Jeruzal; K. D. Brinker

368

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

369

BASIC and the Density of Glass. A First-Year Laboratory/Computer Experiment.  

ERIC Educational Resources Information Center

Describes a first-year chemistry laboratory experiment which uses a simple computer program written in BASIC, to analyze data collected by students about the density of a set of marbles. A listing of the program is provided, along with a sample printout of the experiment's results. (TW)

Harris, Arlo D.

1986-01-01

370

Estimation of hydraulic conductivity and water table map in a large-scale laboratory model by means of the self-potential method  

NASA Astrophysics Data System (ADS)

The goal of this paper is to estimate the position of the water table and hydraulic conductivity of a homogeneous porous medium by means of the self-potential method. The hydrogeophysical experiments were carried out at the Hydrogeosite Laboratory of the Istituto di Metodologie per l'Analisi Ambientale, Consiglio Nazionale delle Ricerche (Marsico Nuovo, Italy); the laboratory is a large-scale model sized 10 × 7 × 3 m3 that is filled with a homogeneous medium made up of quartz-rich sand with a medium-high hydraulic conductivity in the order of 10-5 m s-1. Self-potential signals generated by the groundwater flow, during a pumping test, were measured on the ground surface, on both the pumping and the recovery phases. A novel methodology to estimate the hydraulic conductivity from self-potential measurements is proposed. Hydraulic conductivity very close to that calculated from hydraulic data, by means of Neuman-type curves, has been obtained by solving the electrical flow equation through a linear least squares method. Moreover, a kriging with external drift geostatistical methodology has been proposed to estimate the hydraulic head distribution. The advantages given by this geostatistical method are that (1) hydraulic head distribution can be estimated without any previous electrokinetic coupling coefficient calculation and (2) the method is valid for either linear or nonlinear relationships between self-potential and hydraulic head gradients. An original finding of this work is that the relationship between self-potential signals and drawdown, around a pumping well, is not always linear: linearity applies only when the groundwater velocity is low, but high nonlinearity occurs when hydraulic head gradient rises up. Kriging with the external drift method could be used for the inversion of the hydraulic conductivity distribution, in a real heterogeneous aquifer, by means of an appropriate conditioning technique.

Straface, Salvatore; Rizzo, Enzo; Chidichimo, Francesco

2010-06-01

371

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

372

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

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

Sea experiments of the Underway Conductivity-Temperature-Depth prototype made in China  

NASA Astrophysics Data System (ADS)

A new instrument for upper ocean survey, namely the UCTD (Underway Conductivity-Temperature-Depth), which combines some of the advantages of other underway instruments, is introduced in this paper. The Introduction section presents a description of the construction and function of the UCTD, and the experiments conducted in the South China Sea on board the R/V Dong Fang Hong 2 in July 2007 and August 2008. The UCTD system, with pressure and temperature sensors in the probe, is conveniently portable, cost-effective and environment-friendly. It is hopefully suitable for future cruises. An intercomparison based on regressing with the experiment temperature data from both SeaBird plus911 CTD and the UCTD showed that the standard deviation is 0.88°C and the correlation coefficient is 0.96, achieving the goals set for the current oceanography uses. In the hydrodynamic experiments, the descending velocities and depths were calculated for different ship speeds. A pulling test was designed with a tensiometer to measure the magnitude of the pull. The maximal tension of the line was found to be 66.2 kg, which is far lower than the bearing limit of the Hollow Spectra line. Finally, some improvement suggestions are put forward for future experiments and production.

Song, Xiangzhou; Li, Hui; Lin, Xiaopei; Chen, Xueen; Guo, Xinshun; Tian, Jiwei

2009-12-01

375

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

376

Laboratory: Undergraduate Laboratory Experiment Teaching Fundamental Concepts of Rheology in Context of Sickle Cell Anemia  

ERIC Educational Resources Information Center

This paper describes a biomedical engineering experiment that introduces students to rheology. Healthy and sickle-cell blood analogs are prepared that are composed of chitosan particles suspended in aqueous glycerol solutions, which substitute for RBCs and plasma, respectively. Students study flow properties of the blood analogs with a viscometer…

Vernengo, Jennifer; Purdy, Caitlin; Farrell, Stephanie

2014-01-01

377

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

378

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

379

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

380

FLARE (Facility for Laboratory Reconnection Experiments): A Major Next-Step for Laboratory Studies of Magnetic Reconnection  

NASA Astrophysics Data System (ADS)

A new intermediate-scale plasma experiment, called the Facility for Laboratory Reconnection Experiments or FLARE (flare.pppl.gov), is under construction at Princeton as a joint project by five universities and two national labs to study magnetic reconnection in regimes directly relevant to heliophysical and astrophysical plasmas. The currently existing small-scale experiments have been focusing on the single X-line reconnection process in plasmas either with small effective sizes or at low Lundquist numbers, both of which are typically very large in natural plasmas. These new regimes involve multiple X-lines as guided by a reconnection "phase diagram", in which different coupling mechanisms from the global system scale to the local dissipation scale are classified into different reconnection phases [H. Ji & W. Daughton, Phys. Plasmas 18, 111207 (2011)]. The design of the FLARE device is based on the existing Magnetic Reconnection Experiment (MRX) (mrx.pppl.gov) and is to provide experimental access to the new phases involving multiple X-lines at large effective sizes and high Lundquist numbers, directly relevant to magnetospheric, solar wind, and solar coronal plasmas. After a brief summary of recent laboratory results on the topic of magnetic reconnection, the motivating major physics questions, the construction status, and the planned collaborative research especially with heliophysics communities will be discussed.

Ji, Hantao; Bhattacharjee, A.; Prager, S.; Daughton, W.; Bale, Stuart D.; Carter, T.; Crocker, N.; Drake, J.; Egedal, J.; Sarff, J.; Fox, W.; Jara-Almonte, J.; Myers, C.; Ren, Y.; Yamada, M.; Yoo, J.

2015-04-01

381

Testing the relationship between levels of endogenous testosterone and physiological responses to facial expressions in men: an experiment conducted by students in an undergraduate behavioral neuroscience class.  

PubMed

To determine if endogenous testosterone (T) is related to physiological responses to aggressive stimuli in human males, students in a behavioral neuroscience laboratory class conducted an experiment that determined if levels of salivary T in adult males are correlated with autonomic and/or somatic responses to angry facial expressions. Each student collected a saliva sample from one subject and, within 30 minutes of collecting the sample, measured heart rate (HR), skin conductance (SC), and corrugator supercilii electromyographic (EMG) responses to emotionally neutral, happy, and angry male facial expressions. Salivary T levels were analyzed by an enzyme-linked immunoassay. A significant, positive correlation was found between levels of salivary T and HR responses to angry and happy, but not neutral, male facial expressions. This laboratory experience not only provided students with the opportunity to design and conduct a scientific experiment, but it also generated preliminary data suggesting that levels of salivary T collected within 30 minutes of testing are related to autonomic responses to emotional social stimuli in humans. If verified by future experiments, this finding would be consistent with the hypothesis that fluctuations in circulating T might influence ongoing social behavior in human males by rapidly modulating autonomic responses to emotional social stimuli. The potential significance of such a general mechanism for the regulation of aggressive behavior is discussed. PMID:23741200

Thompson, Richmond R; George, Kirsten

2003-01-01

382

DebriSat - A Planned Laboratory-Based Satellite Impact Experiment for Breakup Fragment Characterization  

NASA Technical Reports Server (NTRS)

DebriSat is a planned laboratory ]based satellite hypervelocity impact experiment. The goal of the project is to characterize the orbital debris that would be generated by a hypervelocity collision involving a modern satellite in low Earth orbit (LEO). The DebriSat project will update and expand upon the information obtained in the 1992 Satellite Orbital Debris Characterization Impact Test (SOCIT), which characterized the breakup of a 1960 's US Navy Transit satellite. There are three phases to this project: the design and fabrication of an engineering model representing a modern, 50-cm/50-kg class LEO satellite known as DebriSat; conduction of a laboratory-based hypervelocity impact to catastrophically break up the satellite; and characterization of the properties of breakup fragments down to 2 mm in size. The data obtained, including fragment size, area ]to ]mass ratio, density, shape, material composition, optical properties, and radar cross ]section distributions, will be used to supplement the DoD fs and NASA fs satellite breakup models to better describe the breakup outcome of a modern satellite. Updated breakup models will improve mission planning, environmental models, and event response. The DebriSat project is sponsored by the Air Force fs Space and Missile Systems Center and the NASA Orbital Debris Program Office. The design and fabrication of DebriSat is led by University of Florida with subject matter experts f support from The Aerospace Corporation. The major milestones of the project include the complete fabrication of DebriSat by September 2013, the hypervelocity impact of DebriSat at the Air Force fs Arnold Engineering Development Complex in early 2014, and fragment characterization and data analyses in late 2014.

Liou, J.-C.; Fitz-Coy, N.; Werremeyer, M.; Huynh, T.; Voelker, M.; Opiela, J.

2012-01-01

383

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

384

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

385

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

386

Using Calculator-Based Laboratory Technology to Conduct Undergraduate Chemical Research  

NASA Astrophysics Data System (ADS)

Calculator-based laboratory (CBL) technology can be used to initiate a viable undergraduate research program and at the same time teach ethical behavior in science and research. One research project, utilizing buckminsterfullerene, is described as a prototype of the quality and scope of such chemical research programs. Eight original research project ideas are presented for undergraduates to pursue using readily available materials and pH, colorimeter, relative humidity, temperature, light, carbon dioxide, and dissolved oxygen probes.

See Letter re: this article.

Sales, Cynthia L.; Ragan, Nicole M.; Kendrick Murphy, Maureen

2001-05-01

387

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

388

Improved predictions of saturated and unsaturated zone drawdowns in a heterogeneous unconfined aquifer via transient hydraulic tomography: Laboratory sandbox experiments  

NASA Astrophysics Data System (ADS)

SummaryInterpretation of pumping tests in unconfined aquifers has largely been based on analytical solutions that disregard aquifer heterogeneity. In this study, we investigate whether the prediction of drawdown responses in a heterogeneous unconfined aquifer and the unsaturated zone above it with a variably saturated groundwater flow model can be improved by including information on hydraulic conductivity (K) and specific storage (Ss) from transient hydraulic tomography (THT). We also investigate whether these predictions are affected by the use of unsaturated flow parameters estimated through laboratory hanging column experiments or calibration of in situ drainage curves. To investigate these issues, we designed and conducted laboratory sandbox experiments to characterize the saturated and unsaturated properties of a heterogeneous unconfined aquifer. Specifically, we conducted pumping tests under fully saturated conditions and interpreted the drawdown responses by treating the medium to be either homogeneous or heterogeneous. We then conducted another pumping test and allowed the water table to drop, similar to a pumping test in an unconfined aquifer. Simulations conducted using a variably saturated flow model revealed: (1) homogeneous parameters in the saturated and unsaturated zones have a difficult time predicting the responses of the heterogeneous unconfined aquifer; (2) heterogeneous saturated hydraulic parameter distributions obtained via THT yielded significantly improved drawdown predictions in the saturated zone of the unconfined aquifer; and (3) considering heterogeneity of unsaturated zone parameters produced a minor improvement in predictions in the unsaturated zone, but not the saturated zone. These results seem to support the finding by Mao et al. (2011) that spatial variability in the unsaturated zone plays a minor role in the formation of the S-shape drawdown-time curve observed during pumping in an unconfined aquifer.

Berg, Steven J.; Illman, Walter A.

2012-11-01

389

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

390

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

NASA Astrophysics Data System (ADS)

Medium 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

391

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

392

CO2 release experiment in the shallow subsurface at the Brackenridge Field Laboratory and numerical modeling  

NASA Astrophysics Data System (ADS)

Soil gas monitoring is one cost-effective approach to detect CO2 leak at geological sequestration sites. Therefore understanding CO2 gas transport in soil zones is important for detection of CO2 leaks. A field experiment of a small CO2 release was conducted at the Brackenridge Field Laboratory, the University of Texas at Austin. The field site consists of one injection well, two sensor wells and one gas station well (Figure 1). The injection well was completed with a PVC pipe to a depth of 1.1 m below surface. CO2 sensors were deployed in sensor wells about 42 cm from the injection well at depths of 1.1 m having no subsurface PVC pipes but only a PVC protector cap at the surface. The gas monitoring station about 72 cm away from the injection well contains 3 copper tubes each set at different depths in sand pack isolated with bentonite clay. The CO2 release experiment started on March 4, 2009. A total 36.76 liters of CO2 were injected at 1 m depth at a rate of 100 ml/minute for 6 hours. Subsurface CO2 gas concentrations (before, during, and after the injection) were continuously monitored in sensor wells. Real-time CO2 concentrations were monitored at the gas station using an SRI 8610 gas chromatograph (GC) fitted with flame ionization detector (FID) and a thermal conductivity detector (TCD). A numerical model was constructed to simulate CO2 release experiments. The model takes into account CO2 diffusion and dissolution in pore water. Air in the pore space is assumed stagnant. Model domain consists of four soil layers and one atmospheric layer. The groundwater table is about 2.4 meters below ground surface. The model was calibrated with respect to diffusion coefficient (transport parameter) and the injection rate (mass parameter). Model results fit well with CO2 measurements at the sensor wells and the gas station. However, the calibrated injection rate underestimates measured injection rate.

Yang, C.; Romanak, K.; Hovorka, S.

2009-12-01

393

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

394

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. PMID:23653550

TARAS, LORETTA BRANCACCIO

2003-01-01

395

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

396

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

397

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

SciTech Connect

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 of limited original equipment manufacturer (OEM) model availability. Approximately 90% of all conversions were performed on compact of full-size vans and pickups, and 90% of the conversions were to bi-fuel operation. With a positive response from the fleet managers, this program helped the Federal government meet the vehicle acquisition requirements of EPACT for fiscal years 1993 and 1994, despite limited OEM model availability. The conversions also helped to establish the infrastructure needed to support further growth in the use of alternative fuel vehicles. In conclusion, the program has been successful in helping the Federal government meet the vehicle acquisition requirements of EPACT, establishing infrastructure, increasing the displacement of imported oil, and evaluating the emissions performance of converted vehicles. With the relatively widespread availability of OEM vehicles in the 1996 model year, the program is now being phased out.

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

1996-04-01

398

Laboratory experiments on rainfall-induced flowslide from pore pressure and moisture content measurements  

NASA Astrophysics Data System (ADS)

During or immediately after rainfall many slope failures have been observed. The slope failure occurred due to rainfall infiltration that rapidly increase the pore pressure and trigger the slope failure. Numerous studies have been conducted to investigate the rainfall-induced slope failure, but the mechanism of slope failure is still not well clarified. To investigate mechanism of rainfall-induced slope failure laboratory experiments have been conducted in flume. The slope was prepared with sandy soil in flume with constant inclination of 45°, because most of rainfall-induced slope failure occurred in sandy soil and on steep slope. The hydrological parameters such as pore pressure and moisture content were measured with piezometers and advanced Imko TDRs respectively. The slope failure occurred due to increase in moisture content and rise in pore pressure. During the flowslide type of slope failure the sudden increase in pore pressure was observed. The higher moisture content and pore pressure was at the toe of the slope. The pore pressure was higher at the toe of the slope and smaller at the upper part of the slope. After the saturation the run-off was observed at the toe of the slope that erodes the toe and forming the gullies from toe to upper part of the slope. In the case antecedent moisture conditions the moisture content and the pore pressure increased quickly and producing the surface runoff at the horizontal part of the slope. The slope having less density suffer from flowslide type of the failure, however in dense slope no major failure was occurred even at higher rainfall intensity. The antecedent moisture accompanied with high rainfall intensity also not favors the initiation of flowslide in case of dense slope. The flowslide type of failure can be avoided by controlling the density of soil slope. Knowing such parameters that controls the large mass movement helpful in developing the early warning system for flowslide type of failure.

Hakro, M. R.; Harahap, I. S. H.

2015-02-01

399

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

400

Feasibility study of a zero-gravity (orbital) atmospheric cloud physics experiments laboratory  

NASA Technical Reports Server (NTRS)

A feasibility and concepts study for a zero-gravity (orbital) atmospheric cloud physics experiment laboratory is discussed. The primary objective was to define a set of cloud physics experiments which will benefit from the near zero-gravity environment of an orbiting spacecraft, identify merits of this environment relative to those of groundbased laboratory facilities, and identify conceptual approaches for the accomplishment of the experiments in an orbiting spacecraft. Solicitation, classification and review of cloud physics experiments for which the advantages of a near zero-gravity environment are evident are described. Identification of experiments for potential early flight opportunities is provided. Several significant accomplishments achieved during the course of this study are presented.

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

1972-01-01

401

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

402

Bacterial Etiologies of Five Core Syndromes: Laboratory-Based Syndromic Surveillance Conducted in Guangxi, China  

PubMed Central

Background Under the existing national surveillance system in China for selected infectious diseases, bacterial cultures are performed for only a small percentage of reported cases. We set up a laboratory-based syndromic surveillance system to elucidate bacterial etiologic spectrum and detect infection by rare etiologies (or serogroups) for five core syndromes in the given study area. Methods Patients presenting with one of five core syndromes at nine sentinel hospitals in Guagnxi, China were evaluated using laboratory-based syndrome surveillance to elucidate bacterial etiologies. We collected respiratory and stool specimens, as well as CSF, blood and other related samples for bacterial cultures and pulse field gel electrophoresis (PFGE) assays. Results From February 2009 to December 2011, 2,964 patients were enrolled in the study. Etiologies were identified in 320 (10.08%) patients. Streptococcus pneumonia (37 strains, 24.18%), Klebsiella pneumonia (34, 22.22%), Pseudomonas aeruginosa (19, 12.42%) and Haemophilus influenza (18, 11.76%) were the most frequent pathogens for fever and respiratory syndrome, while Salmonella (77, 81.05%) was most often seen in diarrhea syndrome cases. Salmonella paratyphi A (38, 86.36%) occurred in fever and rash syndrome, with Cryptococcus neoformans (20, 35.09%), Streptococcus pneumonia (5, 8.77%), Klebsiella pneumonia (5, 8.77%),streptococcus suis (3, 5.26%) and Neisseria meningitides group B (2, 3.51%) being the most frequently detected in encephalitis-meningitis syndrome. To date no pathogen was isolated from the specimens from fever and hemorrhage patients. Conclusions In addition to common bacterial pathogens, opportunistic pathogens and fungal infections require more attention. Our study contributes to the strengthening of the existing national surveillance system and provides references for other regions that are similar to the study area. PMID:25360596

Dong, Baiqing; Liang, Dabin; Lin, Mei; Wang, Mingliu; Zeng, Jun; Liao, Hezhuang; Zhou, Lingyun; Huang, Jun; Wei, Xiaolin; Zou, Guanyang; Jing, Huaiqi

2014-01-01

403

Training related research and development conducted at Oak Ridge National Laboratory for the US Nuclear Regulatory Commission  

SciTech Connect

For a number of years Oak Ridge National Laboratory (ORNL) has conducted a sizeable program of human factors research and development in support of the Office of Nuclear Regulatory Research of the US Nuclear Regulatory Commission (NRC). The history of this effort has in many ways paralleled the growth of human factors R and D throughout the nuclear industry and the program has contributed to advances in the industry as well as to NRC regulatory and research programs. This paper reviews the major projects and products of the program relevant to training and concludes with an identification of future R and D needs.

Haas, P.M.

1985-01-01

404

Variable conductance heat pipe technology. [research project resulting in heat pipe experiment on OAO-3 satellite  

NASA Technical Reports Server (NTRS)

A research and development program in variable conductance heat pipe technology is reported. The project involved: (1) theoretical and/or experimental studies in hydrostatics, (2) hydrodynamics, (3) heat transfer into and out of the pipe, (4) fluid selection, and (5) materials compatibility. The development, fabrication, and test of the space hardware resulted in a successful flight of the heat pipe experiment on the OAO-3 satellite. A summary of the program is provided and a guide to the location of publications on the project is included.

Anderson, W. T.; Edwards, D. K.; Eninger, J. E.; Marcus, B. D.

1974-01-01

405

Comparison of Fire Model Predictions with Experiments Conducted in a Hangar With a 15 Meter Ceiling  

NASA Technical Reports Server (NTRS)

The purpose of this study is to examine the predictive capabilities of fire models using the results of a series of fire experiments conducted in an aircraft hangar with a ceiling height of about 15 m. This study is designed to investigate model applicability at a ceiling height where only a limited amount of experimental data is available. This analysis deals primarily with temperature comparisons as a function of distance from the fire center and depth beneath the ceiling. Only limited velocity measurements in the ceiling jet were available but these are also compared with those models with a velocity predictive capability.

Davis, W. D.; Notarianni, K. A.; McGrattan, K. B.

1996-01-01

406

Soil Science self-learning based on the design and conduction of experiments  

NASA Astrophysics Data System (ADS)

This paper presents an experience for introducing the methodology of project-based learning (PBL) in the area of Soil Science in the University of Sevilla (Spain). Currently, teachers try to enhance practical experience of university students in a complementary manner to theoretical knowledge. However, many times this is a difficult process. Practice is an important part of personal work in the vast majority of subjects that degree students receive, since the implementation of the EHEA. In most cases, these experiences are presented as partial small experiments or projects, assigned to the area-specific knowledge agenda. Certain sciences, such as Soil Science, however, require synthesis and integration capabilities of previous knowledge. It is therefore necessary to develop practical programs that address the student not only to the performance of laboratory determinations, but to the formulation of hypotheses, experimental design and problem solving, whether in groups or individually, situated in a wide context and allowing students to make connections with other areas of knowledge. This project involves the development of teamwork experiments, for the study real cases and problems and making decisions in the field of Soil Science. The results of the experimental work were publicly exposed as posters and oral presentations and were discussed during a mini-congress open to students and a general audience. The open and dynamic nature of the project substantially improves student motivation, which adds value to our project. Due to the multidisciplinary character of Soil Science it is relatively easy to propose projects of some complexity, and therefore, provides good conditions for introducing the PBL methodology. The teacher's role is also important and is not limited to observe or qualify the students, but it is a catalyst for learning. It is important that teacher give the leadership of the process and make the students themselves feel the protagonists of the project.

Jordán, A.; Bárcenas-Moreno, G.; Zavala, L. M.

2012-04-01

407

Laboratory and model simulations of a LNAPL spill in a variably-saturated sand, 1. Laboratory experiment and image analysis techniques  

NASA Astrophysics Data System (ADS)

A two-dimensional, multiphase flow experiment was conducted in the laboratory. The saturation distribution of a lighter than water non-aqueous-phase liquid (LNAPL) as it migrated through a variably-saturated sand medium was determined using image analysis techniques. The pressures in the water and LNAPL phases were measured using hydrophilic and hydrophobic porous cups connected to a series of pressure transducers and a data acquisition system. The LNAPL inflow and water outflow were also recorded. A series of capillary pressure-saturation experiments were conducted for each two-phase system. The capillary pressures recorded by the pressure transducers were used to calculate the pphase saturations based on a fully hysteretic capillary pressure-saturation algorithm. The static equilibrium capillary pressure-saturation relationships proved to be invalid immediately ahead of the LNAPL front. The capillary pressure-saturation relationship appeared to be dynamic for short periods of time as the LNAPL front arrived at each transducer location. The presence of an entrapped air phase as the LNAPL migrated through the unsaturated zone clearly affected the migration of the LNAPL and the maximum LNAPL saturation reached in the sand medium.

Van Geel, P. J.; Sykes, J. F.

1994-11-01

408

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

409

Laboratory Experiments to Evaluate Diffusion of 14C into Nevada Test Site Carbonate Aquifer Matrix  

SciTech Connect

Determination of groundwater flow velocities at the Nevada Test Site is important since groundwater is the principal transport medium of underground radionuclides. However, 14C-based groundwater velocities in the carbonate aquifers of the Nevada Test Site are several orders of magnitude slower than velocities derived from the Underground Test Area regional numerical model. This discrepancy has been attributed to the loss or retardation of 14C from groundwater into the surrounding aquifer matrix making 14C-based groundwater ages appear much older. Laboratory experiments were used to investigate the retardation of 14C in the carbonate aquifers at the Nevada Test Site. Three sets of experiments were conducted evaluating the diffusion of 14C into the carbonate aquifer matrix, adsorption and/or isotopic exchange onto the pore surfaces of the carbonate matrix, and adsorption and/or isotopic exchange onto the fracture surfaces of the carbonate aquifer. Experimental results a nd published aquifer matrix and fracture porosities from the Lower Carbonate Aquifer were applied to a 14C retardation model. The model produced an extremely wide range of retardation factors because of the wide range of published aquifer matrix and fracture porosities (over three orders of magnitude). Large retardation factors suggest that groundwater with very little measured 14C activity may actually be very young if matrix porosity is large relative to the fracture porosity. Groundwater samples collected from highly fractured aquifers with large effective fracture porosities may have relatively small correction factors, while samples from aquifers with a few widely spaced fractures may have very large correction factors. These retardation factors were then used to calculate groundwater velocities from a proposed flow path at the Nevada Test Site. The upper end of the range of 14C correction factors estimated groundwater velocities that appear to be at least an order of magnitude too high compared to published velocities. The lower end of the range of 14C correction factors falls within the range of reported velocities. From these results, future experimental studies (both laboratory and field scale) to support 14C groundwater age dating should focus on obtaining better estimates of aquifer properties including matrix and fracture porosities.

Ronald L. Hershey; William Howcroft; Paul W. Reimus

2003-03-01

410

Measurement of advective soil gas flux: Results of field and laboratory experiments with CO2  

SciTech Connect

We modified our multi-channel, steady-state flow-through (SSFT), soil-CO2 flux monitoring system to include an array of inexpensive pyroelectric non-dispersive infrared detectors for full-range (0-100%) coverage of CO2 concentrations without dilution, and a larger-diameter vent tube. We then conducted field testing of this system from late July through mid-September 2010 at the Zero Emissions Research and Technology (ZERT) project site located in Bozeman, MT, and subsequently, laboratory testing at the Pacific Northwest National Laboratory (PNNL) in Richland, WA using a flux bucket filled with dry sand. In the field, an array of twenty-five SSFT and three non-steady-state (NSS) flux chambers was installed in a 10x4 m area, the long boundary of which was directly above a shallow (2-m depth) horizontal injection well located 0.5 m below the water table. Two additional chambers (one SSFT and one NSS) were installed 10 m from the well for background measurements. Volumetric soil moisture sensors were installed at each SSFT chamber to measure mean levels in the top 0.15 m of soil. A total flux of 52 kg CO2 d-1 was injected into the well for 27 d and the efflux from the soil was monitored by the chambers before, during, and for 27 d after the injection. Overall, the results were consistent with those from previous years, showing a radial efflux pattern centered on a known “hot spot”, rapid responses to changes in injection rate and wind power, evidence for movement of the CO2 plume during the injection, and nominal flux levels from the SSFT chambers that were up to 6-fold higher than those measured by adjacent NSS chambers. Soil moisture levels varied during the experiment from moderate to near saturation with the highest levels occurring consistently at the hot spot. The effects of wind on measured flux were complex and decreased as soil moisture content increased. In the laboratory, flux bucket testing with the SSFT chamber showed large measured-flux enhancement due to the Venturi effect on the chamber vent, but an overall decrease in measured flux when wind also reached the sand surface. Flux-bucket tests at a high flux (comparable to that at the hot spot) also showed that the measured flux levels increase linearly with the chamber-flushing rate until the actual level is reached. At the SSFT chamber-flushing rate used in the field experiment the measured flux in the laboratory was only about a third of the actual flux. The ratio of measured to actual flux increased logarithmically as flux decreased, and reached parity at low levels typical of diffusive flux systems. Taken together, our results suggest that values for advective CO2 flux measured by SSFT and NSS chamber systems are likely to be significantly lower than the actual values due to back pressure developed in the chamber that diverts flux from entering the chamber. Chamber designs that counteract the back pressure and also avoid large Venturi effects associated with vent tubes, such as the SSFT with a narrow vent tube operated at a high chamber-flushing rate, are likely to yield flux measurements closer to the true values.

Amonette, James E.; Barr, Jonathan L.; Erikson, Rebecca L.; Dobeck, Laura M.; Barr, Jamie L.; Shaw, Joseph A.

2013-10-01

411

A summary of results from laboratory ice nucleation experiments: current state of scientific understanding and parameterization developments  

NASA Astrophysics Data System (ADS)

Laboratory experiments under controlled conditions with well-characterized aerosol particles are conducted by many research groups worldwide with the aim to gain new insights into the mechanism of heterogeneous ice formation. Several parameterizations of ice formation in tropospheric clouds for use in numerical models are based on these data. We will present a compilation of laboratory results on heterogeneous ice nucleation in the deposition, condensation and immersion nucleation modes on mineral dust, soot, biological and organic particles. The data set is analysed with respect to consistent signatures, such as size or surface area dependence, ice nucleation efficiency below and close to water saturation, sensitivity to coatings or surface treatments, and composition. It is shown that a proportionality of the ice nuclei number to the particle surface area is found in immersion and condensation freezing experiments for mineral dust particles, even across different experimental methods and over a wide range of particles sizes and temperatures. Some biological particles exhibit similar ice nuclei numbers per surface area to mineral dusts, while others are significantly more active. For soot, experimental results show a wide spread and no consistent relation to surface area can be derived. Recent approaches for laboratory-based ice nucleation will be discussed and compared to the multitude of measurements. The approaches include time-independent and time-dependent (often referred to as singular and stochastic) formulations, in particular the "active site density" parameterization and nucleation rates based on classical nucleation theory, with either a constant contact angle or a distribution of contact angles.

Hoose, C.; Möhler, O.

2011-12-01

412

Anisotropy of electrical conductivity of the excavation damaged zone in the Mont Terri Underground Rock Laboratory  

NASA Astrophysics Data System (ADS)

Electrical resistivity measurements were performed to characterize the anisotropy of electrical resistivity of the excavation damaged zone (EDZ) at the end-face of a gallery in the Opalinus clay of the Mont Terri Underground Rock Laboratory (URL). The data were acquired with a combination of square arrays in 18 zones on the gallery's face and in two series of four boreholes perpendicular to the face. Each data set is independently inverted using simulated annealing to recover the resistivity tensor. Both the stability and the non-uniqueness of the inverse problem are discussed with synthetic examples. The inversion of the data shows that the face is split in two domains separated by a tectonic fracture, with different resistivity values but with a common orientation. The direction of the maximum resistivity is found perpendicular to the bedding plane, and the direction of minimum resistivity is contained in the face's plane. These results show that the geo-electrical structure of the EDZ is controlled by a combination of effects due to tectonics, stratigraphy, and recent fracturing produced by the excavation of the gallery.

Nicollin, Florence; Gibert, Dominique; Lesparre, Nolwenn; Nussbaum, Christophe

2010-04-01

413

Experimenting from a distance—determination of speed of light by a remotely controlled laboratory (RCL)  

NASA Astrophysics Data System (ADS)

The speed of light is an essential topic in the teaching of physics at school and at university, either with respect to the type of experiment or of course with respect to its genuine inherent importance. In reality, the various available experiments are hardly ever performed in class for many reasons. Therefore, we offer this experiment as a remotely controlled laboratory (RCL). An RCL is a real experiment setup at location A which can be controlled via the Internet by a user at a distant location B. It allows several actions like in the hands-on experiment and delivers convincing results. Finally, we present experiences of the use of the RCL, describe the added value of this experiment as an RCL and give hints for implementing the RCL in teaching.

Gröber, S.; Vetter, M.; Eckert, B.; Jodl, H.-J.

2010-05-01

414

Intraguild predation, cannibalism, and microhabitat use in Calopteryx virgo and Somatochlora metallica larvae: a laboratory experiment  

Microsoft Academic Search

Intraguild predation (IGP) and cannibalism among co-occurring lotic odonate species was studied in Central Finland. A laboratory\\u000a experiment was performed to assess the microhabitat use and cannibalism between intermediate and late instars of Calopteryx virgo larvae and predation by larger Somatochlora metallica larvae on the intermediate C. virgo instars. The experiment was run in small running-water aquaria where the larvae

Jari Ilmonen; Jukka Suhonen

2006-01-01

415

First results of the IGEX dark matter experiment at the Canfranc Underground Laboratory  

Microsoft Academic Search

The enriched 76Ge double-beta decay detectors from the International Germanium EXperiment (IGEX), operating in the Canfranc Underground Laboratory with an overbuden of 2450 m.w.e., were recently upgraded to use them also in a search for WIMPs. This paper presents a description of the experiment and the data analysis as well as a new exclusion plot, ?(m), derived from the IGEX

S. Cebrián; A. Morales; C. E. Aalseth; F. T. Avignone; R. L. Brodzinski; E. García; D. González; W. K. Hensley; I. G. Irastorza; I. V. Kirpichnikov; A. A. Klimenko; H. S. Miley; J. Morales; A. Ortiz de Solórzano; S. B. Osetrov; V. S. Pogosov; J. Puimedón; J. H. Reeves; M. L. Sarsa; S. Scopel; A. A. Smolnikov; A. G. Tamanyan; A. A. Vasenko; S. I. Vasiliev; J. A. Villar

2001-01-01

416

Collisionless plasma interpenetration in a strong magnetic field for laboratory astrophysics experiments  

SciTech Connect

A theoretical analysis for astrophysics-oriented laser-matter interaction experiments in the presence of a strong ambient magnetic field is presented. It is shown that the plasma collision in the ambient magnetic field implies significant perturbations in the electron density and magnetic field distribution. This transient stage is difficult to observe in astrophysical phenomena, but it could be investigated in laboratory experiments. Analytic models are presented, which are supported by particles-in-cell simulations.

Korneev, Ph., E-mail: korneev@theor.mephi.ru [University Bordeaux 1—CNRS—CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, 33400 Talence (France); National Research Nuclear University “MEPhI”, 115409, Moscow (Russian Federation); D'Humières, E.; Tikhonchuk, V. [University Bordeaux 1—CNRS—CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, 33400 Talence (France)] [University Bordeaux 1—CNRS—CEA, CELIA (Centre Lasers Intenses et Applications), UMR 5107, 33400 Talence (France)

2014-02-15

417

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

418

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

419

Contact State Monitoring of Simulated Faults at Various Slip Rates by Electrical Conductivity Experiments  

NASA Astrophysics Data System (ADS)

Monitoring the frictional strength of fault with other observables during fault slipping will provide us with valuable information to understand the frictional property of rocks and thus the physics of fault sliding during earthquake. From this viewpoint, we focused on the electrical property of fault, which has a potential to monitor the contact state on the sliding surfaces. To measure the extreme high resistance of dry rocks, we adopted the electrometer (Keithley 6514), which enables us to measure a resistance up to 210 G?. First, we investigated the electrical property of the simulated fault under the static state. We used two cylindrical gabbro samples from India with the diameters of 25 mm and the lengths of 30 mm. The rock samples were installed into the rotary-shear frictional testing apparatus (Fukuyama and Mizoguchi, 2010, Int. J. Fracture; Mizoguchi and Fukuyama, 2010, Int. J. Rock Mech. Min. Sci.) at NIED. Since the electrical response was transient, we considered that the fault should be modeled as a parallel circuit of resistance and capacitance. From the transient response, we estimated the resistance and capacitance of the fault under the normal stress of 0.1 MPa are 66.9 G? and 0.93 nF, respectively. Taking into account the geometric scale, apparent conductivity of the fault between potential electrodes becomes 0.4 nS/m. We also observed increases in the conductivity to 1.4 nS/m and the capacitance to 1.25 nF with increasing the normal stress up to 8 MPa. The increase in conductivity should be caused by the increase in real contact area on the fault associated with the normal stress increase. Here, we calculated the real contact area of fault and the gap between the opposing surfaces (i.e., the thickness of the fault) under the assumption that the contacting asperity on the fault behaves as a resistance and the rest works as a capacitance. The real contact area was estimated to be 8.4 x 10-8 m2, which approximately corresponds to 1/6000 of the whole fault area. The gap distance was estimated to be 4.7 ?m at 0.1 MPa. These geometric parameters were also reasonably estimated for higher normal stress cases; the real contact area increased up to 2.3 x 10-7 m2 and the gap decreased down to 3.8 ?m under the normal stress of 8 MPa. Next, we monitored the conductivity of fault under a constant slow slip rate of 5.3 x 10-3 m/s. and a constant normal stress of 3MPa. Friction coefficient, defined as the ratio of shear stress to normal stress, increased to 0.8 when slip started, then decreased to 0.2 followed by the fluctuation between 0.2 and 0.6. The electrical conductivity data demonstrated quite similar variation to the frictional strength; when the friction coefficient increased, the conductivity increased, and vice versa. This observation can be explained by the idea that the increase in real contact area of fault causes the increase in frictional strength as well as the increase in conductivity. We also conducted the similar experiments at higher slip rate (up to 1m/s) and observed the reasonable variation of conductivity with respect to that of friction coefficient. These results confirm that the conductivity is a superior tool to probe the contact state of the fault slipping at various slip rates.

Yamashita, F.; Fukuyama, E.; Mizoguchi, K.

2011-12-01

420

Laboratory experiments on current flow between stationary and moving electrodes in magnetoplasmas  

NASA Technical Reports Server (NTRS)

Laboratory experiments were performed in order to investigate the basic physics of current flow between tethered electrodes in magnetoplasmas. The major findings are summarized. The experiments are performed in an effectively very large laboratory plasma in which not only the nonlinear current collection is addressed but also the propagation and spread of currents, the formation of current wings by moving electrodes, the current closure, and radiation from transmission lines. The laboratory plasma consists of a pulsed dc discharge whose Maxwellian afterglow provides a quiescent, current-free uniform background plasma. Electrodes consisting of collectors and electron emitters are inserted into the plasma and a pulsed voltage is applied between two floating electrodes via insulated transmission lines. Besides the applied current in the wire, the total current density in the plasma is obtained from space and time resolved magnetic probe measurements via Maxwell's law. Langmuir probes yield the plasma parameters.

Stenzel, Reiner L.; Urrutia, J. M.

1990-01-01

421

Teaching and learning responsible research conduct: influences of prior experiences on acceptance of new ideas.  

PubMed

Despite requirements for Responsible Conduct of Research (RCR) training, little is known about how much this training actually influences the thinking and behaviors of participants. Interview-based qualitative research methods were used to study the reactions of Ph.D. students and postdoctoral fellows to what was taught in an RCR course. For trainees with limited prior RCR experience, or who agreed with what was taught, it was relatively easy to influence their attitudes and how they thought they would use the new information in the future. However, if their prior experiences or existing knowledge conflicted with what was taught they resisted and often rejected new ideas that were presented. Interviews also revealed the tremendously complex process trainees must undergo trying to resolve or integrate all of the different perspectives they receive on RCR from other sources. These results revealed the importance of viewing RCR training from the perspective of learning theory and how prior knowledge influences what people learn. The results also support the need for periodic rather than one-time RCR training to counter the often conflicting views and practices young scientists experience in real-life research settings. PMID:18298028

McGee, Richard; Almquist, Julka; Keller, Jill L; Jacobsen, Steven J

2008-01-01

422

Early experience with the Intel iPSC/860 at Oak Ridge National Laboratory  

SciTech Connect

This report summarizes the early experience in using the Intel iPSC/860 parallel supercomputer at Oak Ridge National Laboratory. The hardware and software are described in some detail, and the machine's performance is studied using both simple computational kernels and a number of complete applications programs.

Heath, M.T.; Geist, G.A.; Drake, J.B. (Oak Ridge National Lab., Oak Ridge, TN (US))

1991-01-01

423

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

424

UPTAKE AND LOSS OF PETROLEUM HYDROCARBONS BY THE MUSSEL, MYTILUS EDULIS, IN LABORATORY EXPERIMENTS  

E-print Network

UPTAKE AND LOSS OF PETROLEUM HYDROCARBONS BY THE MUSSEL, MYTILUS EDULIS, IN LABORATORY EXPERIMENTS ROBERT C. CLARK, JR., AND JOHN S. FINLEY' ABSTRACT Petroleum paraffin hydrocarbons (n-CI4H30 to n-C37H76 system that simulated tides. The mussels were exposed to levels of petroleum hydrocarbons from a surface

425

Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms  

ERIC Educational Resources Information Center

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

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

2014-01-01

426

Women's Experiences in the Engineering Laboratory in Japan  

ERIC Educational Resources Information Center

This qualitative study aims to examine Japanese women undergraduate engineering students' experiences of interacting with departmental peers of the same year in the laboratory setting by using interview data of 32 final-year students at two modestly selective national universities in Japan. Expectation state theory that explains unequal…

Hosaka, Masako

2014-01-01

427

Designing Experiments on Thermal Interactions by Secondary-School Students in a Simulated Laboratory Environment  

ERIC Educational Resources Information Center

Background and purpose: The aim of this study was to explore the effect of investigative activities with manipulations in a virtual laboratory on students' ability to design experiments. Sample: Fourteen students in a lower secondary school in Greece attended a teaching sequence on thermal phenomena based on the use of information and…

Lefkos, Ioannis; Psillos, Dimitris; Hatzikraniotis, Euripides

2011-01-01

428

Laboratory Experiments Concerning Upwellings From the Slab-Graveyard: Implications For Geochemical and Seismic Models  

Microsoft Academic Search

The ongoing plume debate appears to focus on upwellings characterized by large heads and smaller tails, that form from a deep or basal thermal boundary layer (BTBL), which are driven by temperature excesses in the range of 200° C. We use 3-D laboratory experiments to explore how upwellings might differ from this common plume description when BTBLs are influenced by

A. C. Harris; C. Kincaid; P. Hall

2005-01-01

429

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

430

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

431

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

432

Dehydration of 2-Methyl-1-Cyclohexanol: New Findings from a Popular Undergraduate Laboratory Experiment  

ERIC Educational Resources Information Center

The mineral acid-catalyzed dehydration of 2-methyl-1-cyclohexanol has been a popular laboratory exercise in second-year organic chemistry for several decades. The dehydration experiment is often performed by organic chemistry students to illustrate Zaitsev's rule. However, sensitive analytical techniques reveal that the results do not entirely…

Friesen, J. Brent; Schretzman, Robert

2011-01-01

433

Quantum Dots in a Polymer Composite: A Convenient Particle-in-a-Box Laboratory Experiment  

ERIC Educational Resources Information Center

Semiconductor quantum dots are at the forefront of materials science chemistry with applications in biological imaging and photovoltaic technologies. We have developed a simple laboratory experiment to measure the quantum-dot size from fluorescence spectra. A major roadblock of quantum-dot based exercises is the particle synthesis and handling;…

Rice, Charles V.; Giffin, Guinevere A.

2008-01-01

434

Food partitioning by lake-dwelling triclads and glossiphoniid leeches: field and laboratory experiments  

Microsoft Academic Search

The triclads Polycelis tenuis and Dugesia polychroa and the glossiphoniid leeches Glossiphonia complanata and Helobdella stagnalis are abundant on the stony shores of productive British lakes. All species are food limited and there is considerable overlap in the diets of these triclads and leeches. This paper investigates interactions between the two groups using field and laboratory experiments to try to

R. M. H. Seaby; A. J. Martin; J. O. Young

1996-01-01

435

The Kinetics and Inhibition of Gamma-Glutamyl Transpeptidase: A Biochemistry Laboratory Experiment.  

ERIC Educational Resources Information Center

Discusses an enzyme kinetics laboratory experiment involving a two substrate system for undergraduate biochemistry. Uses the enzyme gamma-glutamyl transpeptidase as this enzyme in blood serum is of clinical significance. Notes elevated levels are seen in liver disease, alcoholism, and epilepsy. Uses a spectrophotometer for the analysis. (MVL)

Splittgerber, A. G.; Sohl, Julie

1988-01-01

436

Kinetics of Carboxylesterase: An Experiment for Biochemistry and Physical Chemistry Laboratory.  

ERIC Educational Resources Information Center

Describes a convenient, inexpensive experiment in enzyme kinetics developed for the undergraduate biochemistry laboratory at the University of Virginia. Required are a single beam visible spectrophotometer with output to a recorder, a constant temperature, a commercially available enzyme, substrates, and buffers. (BT)

Nichols, C. S.; Cromartie, T. H.

1979-01-01

437

Microwave-Assisted Esterification: A Discovery-Based Microscale Laboratory Experiment  

ERIC Educational Resources Information Center

An undergraduate organic chemistry laboratory experiment has been developed that features a discovery-based microscale Fischer esterification utilizing a microwave reactor. Students individually synthesize a unique ester from known sets of alcohols and carboxylic acids. Each student identifies the best reaction conditions given their particular…

Reilly, Maureen K.; King, Ryan P.; Wagner, Alexander J.; King, Susan M.

2014-01-01

438

Nitration of Phenols Using Cu(NO[subscript 3])[subscript 2]: Green Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

An easy-to-complete, microwave-assisted, green chemistry, electrophilic nitration method for phenol using Cu(NO[subscript 3])[subscript 2] in acetic acid is discussed. With this experiment, students clearly understand the mechanism underlying the nitration reaction in one laboratory session. (Contains 4 schemes.)

Yadav, Urvashi; Mande, Hemant; Ghalsasi, Prasanna

2012-01-01

439

Coulometric Titration of Ethylenediaminetetraacetate (EDTA) with Spectrophotometric Endpoint Detection: An Experiment for the Instrumental Analysis Laboratory  

ERIC Educational Resources Information Center

Ethylenediaminetetraacetate (EDTA) is commonly used as an anticoagulant in blood-collection procedures. In this experiment for the instrumental analysis laboratory, students determine the quantity of EDTA in commercial collection tubes by coulometric titration with electrolytically generated Cu[superscript 2+]. The endpoint is detected…

Williams, Kathryn R.; Young, Vaneica Y.; Killian, Benjamin J.

2011-01-01

440

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

441

Determination of Mercury in Milk by Cold Vapor Atomic Fluorescence: A Green Analytical Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

Green analytical chemistry principles were introduced to undergraduate students in a laboratory experiment focused on determining the mercury concentration in cow and goat milk. In addition to traditional goals, such as accuracy, precision, sensitivity, and limits of detection in method selection and development, attention was paid to the…

Armenta, Sergio; de la Guardia, Miguel

2011-01-01

442

A Stopped-Flow Kinetics Experiment for the Physical Chemistry Laboratory Using Noncorrosive Reagents  

ERIC Educational Resources Information Center

Stopped-flow kinetics techniques are important to the study of rapid chemical and biochemical reactions. Incorporation of a stopped-flow kinetics experiment into the physical chemistry laboratory curriculum would therefore be an instructive addition. However, the usual reactions studied in such exercises employ a corrosive reagent that can over…

Prigodich, Richard V.

2014-01-01

443

Surface Enhanced Raman Spectroscopy: A Novel Physical Chemistry Experiment for the Undergraduate Laboratory  

Microsoft Academic Search

Raman spectra of molecules adsorbed on metal colloids exhibit large signal enhancements over those of the pure or solution phase samples. This paper presents background information on surface-enhanced Raman spectroscopy (SERS) and provides details for carrying out an SERS experiment in the undergraduate physical chemistry laboratory. A single system, pyridine on silver, has been adapted from the research literature for

Gabriela C. Weaver; Karen Norrod

1998-01-01

444

Gravimetric Analysis of Bismuth in Bismuth Subsalicylate Tablets: A Versatile Quantitative Experiment for Undergraduate Laboratories  

ERIC Educational Resources Information Center

In this laboratory experiment, lower- and upper-division students dissolved bismuth subsalicylate tablets in acid and precipitated the resultant Bi[superscript 3+] in solution with sodium phosphate for a gravimetric determination of bismuth subsalicylate in the tablets. With a labeled concentration of 262 mg/tablet, the combined data from three…

Davis, Eric; Cheung, Ken; Pauls, Steve; Dick, Jonathan; Roth, Elijah; Zalewski, Nicole; Veldhuizen, Christopher; Coeler, Joel

2015-01-01

445

A basic lock-in amplifier experiment for the undergraduate laboratory K. G. Libbrecht,a)  

E-print Network

for the undergraduate laboratory that demonstrates aspects of both the science and the art of precision electronic measurements. The essence of the experiment is to measure the resistance of a small length of brass wire that are often associated with precision electronic measurements. In addition to its intrinsic value

Mahapatra, Rupak

446

Measurement of the Compressibility Factor of Gases: A Physical Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

In this article, we describe an experiment for the undergraduate physical chemistry laboratory in which students measure the compressibility factor of two gases, helium and carbon dioxide, as a function of pressure at constant temperature. The experimental apparatus is relatively inexpensive to construct and is described and diagrammed in detail.…

Varberg, Thomas D.; Bendelsmith, Andrew J.; Kuwata, Keith T.

2011-01-01

447

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

448

Thermodynamics of Sodium Dodecyl Sulfate (SDS) Micellization: An Undergraduate Laboratory Experiment  

ERIC Educational Resources Information Center

An undergraduate laboratory experiment is presented that allows a thermodynamic characterization of micelle formation of sodium dodecyl sulfate (SDS) in aqueous solutions. The critical micelle concentration (CMC) and the degree of micelle ionization (alpha) are obtained at different temperatures by conductimetry. The molar standard free energy…

Marcolongo, Juan P.; Mirenda, Martin

2011-01-01

449

Evaluating data flow diagrams and class diagrams in usability laboratory experiments (CADPRO Pilot #2)  

Microsoft Academic Search

This paper reports on a second pilot experiment for the CADPRO project taking into account a number of the recommendations arising from the first pilot. Three subjects produced data flow diagrams and class diagrams in a usability laboratory setting. Characteristics of subjects' solutions are discussed and the usefulness of profiles of product delivery and constraint activations against time is determined.

SHINGO TAKADA; LOUISE SCOTT; ANDY BROOKS

450

Earthworm excreta attract soil springtails: laboratory experiments on Heteromurus Nitidus (Collembola: Entomobryidae)  

E-print Network

1 Earthworm excreta attract soil springtails: laboratory experiments on Heteromurus Nitidus are often found more abundantly in soils with earthworms than in soils without. Earthworms probably create a favourable environment for microarthropods but few studies have aimed to explain this earthworm effect

Paris-Sud XI, Université de

451

Usnic Acid and the Intramolecular Hydrogen Bond: A Computational Experiment for the Organic Laboratory  

ERIC Educational Resources Information Center

A computational experiment is described for the organic chemistry laboratory that allows students to estimate the relative strengths of the intramolecular hydrogen bonds of usnic and isousnic acids, two related lichen secondary metabolites. Students first extract and purify usnic acid from common lichens and obtain [superscript 1]H NMR and IR…

Green, Thomas K.; Lane, Charles A.

2006-01-01

452

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

453

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

454

The Colorful Chemical Bottle Experiment Kit: From School Laboratory To Public Demonstration  

E-print Network

The blue bottle experiment was first introduced to the chemical education literature as a simple demonstration on kinetics. Its original formulation contains only glucose, NaOH and small amount of methylene blue. The solution turns blue when shaken and fades to colorless upon standing. This bluing/de-bluing cycle may be repeated and may be compared to blood colors in animal's respiratory cycle. Inspired by the blue bottle experiment, the colorful chemical bottle experiment kit was commercially developed in 2006. The kit is a versatile pedagogical tool, not only for physical chemistry but also for analytical, biological and organic chemistry. It also helps teaching concepts in scientific method and laboratory safety. This manuscript contains four parts, brief review on literature relating to the blue bottle experiment, description of the colorful chemical bottle experiment kit, pedagogical discussion of the experiments and preliminary evaluation from students.

Limpanuparb, Taweetham

2015-01-01

455

Critical experiments at Sandia National Laboratories : technical meeting on low-power critical facilities and small reactors.  

SciTech Connect

Sandia National Laboratories (SNL) has conducted radiation effects testing for the Department of Energy (DOE) and other contractors supporting the DOE since the 1960's. Over this period, the research reactor facilities at Sandia have had a primary mission to provide appropriate nuclear radiation environments for radiation testing and qualification of electronic components and other devices. The current generation of reactors includes the Annular Core Research Reactor (ACRR), a water-moderated pool-type reactor, fueled by elements constructed from UO2-BeO ceramic fuel pellets, and the Sandia Pulse Reactor III (SPR-III), a bare metal fast burst reactor utilizing a uranium-molybdenum alloy fuel. The SPR-III is currently defueled. The SPR Facility (SPRF) has hosted a series of critical experiments. A purpose-built critical experiment was first operated at the SPRF in the late 1980's. This experiment, called the Space Nuclear Thermal Propulsion Critical Experiment (CX), was designed to explore the reactor physics of a nuclear thermal rocket motor. This experiment was fueled with highly-enriched uranium carbide fuel in annular water-moderated fuel elements. The experiment program was completed and the fuel for the experiment was moved off-site. A second critical experiment, the Burnup Credit Critical Experiment (BUCCX) was operated at Sandia in 2002. The critical assembly for this experiment was based on the assembly used in the CX modified to accommodate low-enriched pin-type fuel in water moderator. This experiment was designed as a platform in which the reactivity effects of specific fission product poisons could be measured. Experiments were carried out on rhodium, an important fission product poison. The fuel and assembly hardware for the BUCCX remains at Sandia and is available for future experimentation. The critical experiment currently in operation at the SPRF is the Seven Percent Critical Experiment (7uPCX). This experiment is designed to provide benchmark reactor physics data to support validation of the reactor physics codes used to design commercial reactor fuel elements in an enrichment range above the current 5% enrichment cap. A first set of critical experiments in the 7uPCX has been completed. More experiments are planned in the 7uPCX series. The critical experiments at Sandia National Laboratories are currently funded by the US Department of Energy Nuclear Criticality Safety Program (NCSP). The NCSP has committed to maintain the critical experiment capability at Sandia and to support the development of a critical experiments training course at the facility. The training course is intended to provide hands-on experiment experience for the training of new and re-training of practicing Nuclear Criticality Safety Engineers. The current plans are for the development of the course to continue through the first part of fiscal year 2011 with the development culminating is the delivery of a prototype of the course in the latter part of the fiscal year. The course will be available in fiscal year 2012.

Harms, Gary A.; Ford, John T.; Barber, Allison Delo

2010-11-01

456

Fostering expert inquiry skills and beliefs about chemistry through the MORE laboratory experience  

NASA Astrophysics Data System (ADS)

Typical college science instruction fails to promote an accurate view of science as a discipline and a practice. This is likely due to the fact that the