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1

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

2

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

3

Spectroscopic Laboratory Astrophysics Experiments Conducted at the LLNL EBIT Facility in Support of NASA's X-ray Astronomy Flight Program  

NASA Astrophysics Data System (ADS)

The electron beam ion trap (EBIT) facility located at the Lawrence Livermore National Laboratory has been used for laboratory astrophysics experiments for over 15 years. During this time, several unique spectrometers and operating modes have been developed and implemented, including high resolution grating and crystal spectrometers, a high-resolution, high-efficiency NASA/GSFC microcalorimeter array, and the ability to operate and record datawith the electron beam turned off, i.e., in the so-called magnetic trapping mode. Targeted experiments conducted at this facility have addressed specific problems faced by the X-ray astrophysics community and have provided accurate, complete sets of atomic data such as relative and absolute excitation cross sections, transition wavelengths, line polarization, and X-ray signatures of charge exchange recombination. Here we will present a brief overview of our facility and some of the more recent results including 1/4 keV band X- ray emission produced by charge exchange between L-shell sulfur ions and neutral gas, wavelengths and relative intensities of satellite X- ray lines from Na-like Fe XVI and their contribution to the Fe XVII line emission, and the relative intensities of the 3s-2p/3d-2p lines in F-like Fe XVIII and Ni XX. Part of this work was performed under the auspices of the U. S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and is also supported by NASA grants to LLNL, GSFC, and Stanford University.

Brown, Gregory V.; Adams, J. S.; Beiersdorfer, P.; Chen, H.; Clementson, J.; Frankel, M.; Graf, A.; Gu, M. F.; Kahn, S. M.; Kelley, R.; Kilbourne, C. A.; Koutroumpa, D.; Leutenegger, M.; Porter, F.; Wargelin, B.

2009-12-01

4

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.

5

Conducting Miller-Urey Experiments  

NASA Technical Reports Server (NTRS)

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

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

2014-01-01

6

Organic Laboratory Experiments.  

ERIC Educational Resources Information Center

Detailed is a method in which short pieces of teflon tubing may be used for collection tubes for collecting preparative fractions from gas chromatographs. Material preparation, laboratory procedures, and results of this method are discussed. (CW)

Smith, Sherrel

1990-01-01

7

Multiconjugate adaptive optics: laboratory experience.  

PubMed

We present the results from a laboratory multiconjugate adaptive optics experiment. The experiment is differentiated from other published work in that it has a programmable deterministic turbulence generator and an output science camera. The turbulence was generated using a dual layer turbulence emulator, and then corrected using an AO system with 2 wavefront correctors and a Shack-Hartman wavefront sensor, which processed information from five artificial guide stars. We report our results and also describe some of the problems. PMID:19474995

Langlois, M; Saunter, C; Dunlop, C; Myers, R; Love, G

2004-04-19

8

Soap vs. Sanitizer Laboratory Experiment  

E-print Network

Soap vs. Sanitizer Laboratory Experiment #12;Why wash your hands? Hand are the most frequent and grease, which wash away with the water #12;What about hand sanitizer? When water is not available, hand sanitizer can be an effective alternative. The alcohol in hand sanitizer disrupts the coating on bacteria

Rose, Michael R.

9

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 RIDGE NATIONAL LABORATORY Oak Ridge, Tennessee 37831-6285 operated by LOCKHEED MARTIN ENERGY RESEARCH in the Conduct of Research and Development Introduction No quality of the Oak Ridge National Laboratory (ORNL

10

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

11

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

12

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

13

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

14

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

15

Remote laboratory experiments in electrical engineering education  

Microsoft Academic Search

A remote or online laboratory is a laboratory where one can access experiments and instruments or other equipment from outside over the Internet. Laboratories for undergraduate education or vocational training in basic electrical engineering are easy to control remotely. One cannot see or hear the electrical current, so there is no need for sound or video transmission. Computer-based instruments do

Ingvar Gustavsson

2002-01-01

16

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

17

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

18

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

19

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

20

21 CFR 58.130 - Conduct of a nonclinical laboratory study.  

Code of Federal Regulations, 2011 CFR

...false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory Study § 58.130 Conduct of a...

2011-04-01

21

21 CFR 58.130 - Conduct of a nonclinical laboratory study.  

Code of Federal Regulations, 2010 CFR

...false Conduct of a nonclinical laboratory study. 58.130 Section 58.130 Food...LABORATORY PRACTICE FOR NONCLINICAL LABORATORY STUDIES Protocol for and Conduct of a Nonclinical Laboratory Study § 58.130 Conduct of a...

2010-04-01

22

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...

23

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

24

Condor Experience at Brookhaven National Laboratory  

E-print Network

Condor Experience at Brookhaven National Laboratory Alexander Withers RHIC/US ATLAS Computing Facility CondorWeek 2006 #12;(Brief) Facility Overview One of a handful of Laboratories supported/distributed disk storage capacity. ~4000 CPUs available to Condor. 1.8 million SpecInt2000 aggregate computing

Wisconsin at Madison, University of

25

Polaron conductivity mechanism in oxalic acid dihydrate: ac conductivity experiment  

Microsoft Academic Search

The ac electrical conductivity of the oxalic acid dihydrate ( alpha -POX) was investigated as a function of the frequency and temperature. The real part of the complex ac electrical conductivity was found to follow the universal dielectric response sigma'?nus , indicating that hopping or tunneling of localized charge carriers governs the electrical transport. A detailed analysis of the temperature

Adrijan Levstik; Cene Filipic; Vid Bobnar; Iva Levstik; Dusan Hadzi

2006-01-01

26

Laboratory experience for teaching sensory physiology  

NSDL National Science Digital Library

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

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

2009-06-01

27

Cell biology experiments conducted in space  

NASA Technical Reports Server (NTRS)

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

Taylor, G. R.

1977-01-01

28

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

ERIC Educational Resources Information Center

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

Bacon, Michael E.; And Others

1995-01-01

29

A laboratory experiment on internal solitary waves  

NASA Astrophysics Data System (ADS)

A simple laboratory experiment is designed to show the properties of internal solitary waves. The procedure and analysis are suited for a senior undergraduate laboratory course, though the techniques described may also be used for demonstration purposes in a fluid mechanics course. The measurements collected can be compared to the weakly nonlinear Korteweg-deVries (KdV) theory for the wave shape, lengthscale-amplitude relationship, and phase speed. The experiment provides a good introduction to internal solitary waves in the ocean, along with an exploration of error analysis and the limits of applicability of a theory.

Bourgault, Daniel; Richards, Clark

2007-07-01

30

Nucleophilic Aromatic Substitution, A Guided Inquiry Laboratory Experiment.  

PubMed

Inquiry-based learning is a unique student-centered alternative to traditional instruction. This form of active learning is ideal for the organic chemistry laboratory as it encourages critical thinking and hands on problem solving to complete an experiment. Electrophilic Aromatic Substitution is immediately associated with the undergraduate organic chemistry course. However, nucleophilic aromatic substitution is not. The N-arylation of aniline derivatives is a useful reaction for implementing nucleophilic aromatic substitution into the undergraduate curriculum. Under the framework of inquiry-based learning, a straightforward procedure has been developed for the undergraduate laboratory. This experiment explores the reaction rate of the nucleophilic aromatic substitution using various electrophiles. The reaction is conducted under microwave irradiation and the experiment is completed in one laboratory setting. PMID:21197138

Winfield, Leyte L

2010-01-01

31

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

32

Microscale Experiments in the Organic Chemistry Laboratory.  

ERIC Educational Resources Information Center

Discusses the advent of microscale experiments within undergraduate organic chemistry laboratories mainly resulting from environmental safety concerns involving waste disposal. Considers the cost savings in purchasing less reagents and chemicals, the typical glassware and apparatus, the reduced hazards from elimination of open flames, and other…

Williamson, Kenneth L.

1991-01-01

33

Key: Cell Biology 8401 Laboratory Experience  

E-print Network

Key: Cell Biology 8401 f Laboratory Experience Case Presentation Problem Sets Panel Discussion Course Lecture/Assembly LOCATION ROOM 3008 Jordan Hall Cell Biology #12;25 Monday Tuesday 27th Wednesday 28th Thursday 29th Friday 1:303 PM MWF LAB 1:30 3:30 Thurs Cell Biology 8401 Essentials

Humphrey, Marty

34

Optimizing methods in immunocytochemistry: one laboratory's experience.  

PubMed

The addition of immunocytochemical staining procedures to a diagnostic cytology service enables greater specificity of interpretation for many common disease conditions, especially neoplastic diseases. However, well-tested immunohistochemical techniques may require modification for cytologic specimens, and other considerations are necessary when working with air-dried cells. In this article, we describe our experience in evaluating options for sample transport and handling, and discuss methods for obtaining control cells from a variety of tissues for use in immunocytochemical staining. Important immunocytochemical principles and techniques, including fixation, antigen retrieval, and use of primary and secondary antibodies in manual and automated staining systems are described as used in our laboratory for cytologic specimens. Although we emphasize methods relevant to diagnostic laboratories receiving samples from external clients, the information is also applicable to any laboratory interested in adding or enhancing immunocytochemical services. PMID:19351343

Valli, Victor; Peters, Elisabeth; Williams, Cara; Shipp, Lisa; Barger, Anne; Chladny, Jane; Hoffmann, Walter

2009-06-01

35

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

36

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

37

The LUNA experiment at Gran Sasso Laboratory  

NASA Astrophysics Data System (ADS)

Accurate knowledge of thermonuclear reaction rates is a key issue in nuclear astrophysics since it is important for understanding the energy generation, neutrino production and the synthesis of the elements in stars. Cross-section measurements are mainly hampered by the very low counting rate and cosmic background. An underground location is extremely advantageous for such studies, as demonstrated by the LUNA experiment in the Gran Sasso Laboratory (Italy). This paper reports on the results recently obtained by such an experiment and on the future perspectives in this field.

Guglielmetti, Alessandra

2014-09-01

38

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

39

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

40

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

41

MS Musgrave conducts CFES experiment on middeck  

NASA Technical Reports Server (NTRS)

Mission Specialist (MS) Musgrave readies biological sample plate for insertion into Continuous Flow Electrophoresis System (CFES) fluid systems opens biological sample compartment on fluid systems module and documents experiment progress at separation column with 35mm camera. CFES is located on middeck in the galley position (port side wall) with control panel ML86B and water dispenser appearing on the right.

1983-01-01

42

Wheel Abrasion Experiment Conducted on Mars  

NASA Technical Reports Server (NTRS)

Sojourner rover showing Lewis' wheel abrasion experiment. The Mars Pathfinder spacecraft soft-landed on Mars on July 4, 1997. Among the many experiments on its small Sojourner rover are three technology experiments from the NASA Lewis Research Center, including the Wheel Abrasion Experiment (WAE). The WAE was designed, built, delivered, and operated on Mars by a team of engineers and scientists from Lewis' Photovoltaics and Space Environments Branch. This experiment collected data to assess wheel surface wear on the Sojourner. It used a specially designed rover wheel, with thin films (200 to 1000 angstroms) of aluminum, nickel, and platinum deposited on black, anodized aluminum strips attached to the rover's right center wheel. As the wheel spun in the Martian soil, a photovoltaic sensor monitored changes in film reflectivity. These changes indicated abrasion of the metal films by Martian surface material. Rolling wear data were accumulated by the WAE. Also, at frequent intervals, all the rover wheels, except the WAE test wheel, were locked to hold the rover stationary while the test wheel alone was spun and dug into the Martian regolith. These tests created wear conditions more severe than simple rolling. The WAE will contribute substantially to our knowledge of Martian surface characteristics. Marked abrasion would indicate a surface composed of hard, possibly sharply edged grains, whereas lack of abrasion would suggest a somewhat softer surface. WAE results will be correlated with ground simulations to determine which terrestrial materials behave most like those on Mars. This knowledge will enable a deeper understanding of erosion processes on Mars and the role they play in Martian surface evolution. Preliminary results show that electrostatic charging of the rover wheels sometimes caused dust to accumulate on the WAE wheel, making interpretation of the reflectance data problematic. If electrostatic charging is the mechanism for dust attraction, this indicates that the Martian dust has a size somewhat smaller than 40 microns in diameter. The WAE experiment has detected electrostatic charging in the Martian environment for the first time; however, under conditions when the wheel is relatively clean of Martian dust, flight data now indicate that abrasion has also been detected. Crude limits so far place the hardness of the Martian dust at harder than aluminum but softer than nickel, and place the grain size at somewhat smaller than 40 microns.

Ferguson, Dale C.

1998-01-01

43

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

44

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

45

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

E-print Network

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

46

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

47

Laboratory experiments on homogeneous and heterogeneous freezing  

NASA Astrophysics Data System (ADS)

The freezing temperature of the binary H_2SO_4 / H_2O solution droplets has been measured in dependence on their acid concentrations by means of acoustic levitation laboratory experiments. Pure solution droplets were analysed, in order to freeze the droplets as far as possible homogeneously. To induce heterogeneous freezing the droplets were contanimated with substances such as graphite, and the minerals kaolin and montmorillonite. The influence of these particles present in the liquid on the freezing temperature was measured. The size radii of the suspended droplets were between 0,4 - 1,1 mm and the concentration of the liquid acid solution was varied between 5 - 25 weight percent. The experiments show that the pure solution can be supercooled well below the equilibrium curve. Furthermore the presence of foreign particles within the solution increases the freezing temperature. The collected data reveal that the quality of the used particles as nuclei for freezing also depends on the particle material properties. Not only the presence of particles in the solution alone influences the freezing temperature of the droplets, but also the chemical composition and the surface charactaristics. In this contribution details of the experimental conditions are presented together with the measured freezing temperatures.

Borrmann, S.; Ettner, M.; Mitra, S. K.; Hannemann, A.; Sommer, C.; Peter, Th.

2003-04-01

48

An Environment of Conducting Families of Software Engineering Experiments  

E-print Network

an environment that simplifies the process of collecting, managing and sanitizing data from classroom experiments Environment of Conducting Families of 2 #12;Software Engineering Experiments Abstract The classroom of experiments in classroom environments presents a number of challenges to researchers. This paper describes

Basili, Victor R.

49

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

50

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...

51

Organic Laboratory Experiments: Micro vs. Conventional.  

ERIC Educational Resources Information Center

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

Chloupek-McGough, Marge

1989-01-01

52

Laboratory experiments inform iceberg-calving forces  

NASA Astrophysics Data System (ADS)

Globally detected glacial earthquakes are produced during cubic-kilometer scale calving events. The mechanism producing these earthquakes and the dependence of the seismic moment on iceberg size and glacial calving front geometry are not well established. We use a laboratory-scale model of the post-fracture calving process to measure aspects of the calving process not observable in nature. In our experiments, buoyant plastic blocks rest against against a force plate (glacial terminus) which measures both the total force and the torque exerted during the calving process. The blocks are gravitationally unstable, so that they will spontaneously capsize and rotate away from the terminus. We find that hydrodynamics are crucial when considering the coupling between the calving process and the solid earth. There is both a pushing contact force and a simultaneous pulling hydrodynamic force created by a reduced pressure along the terminus face. This suggests that a single couple force mechanism is a more appropriate mode for glacial earthquakes than the commonly used centroid single force model.

Cathles, L. M.; Burton, J. C.

2013-12-01

53

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

54

Review of controlled laboratory experiments on physics of magnetic reconnection  

E-print Network

Review of controlled laboratory experiments on physics of magnetic reconnection Masaaki Yamada from the most recent experiments in the past 2 decades in which magnetic reconnection has been of the reconnection process and its hydromagnetic consequences has been largely theoretical. Laboratory experiments

55

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

56

Laboratory-scale fracture conductivity created by acid etching  

E-print Network

to field conditions and enables analysis of etching pattern and rock strength. A systematic experimental study that covered a variety of formations, acid types, and acid contact times was conducted. An acid fracture conductivity correlation was developed...

Pournik, Maysam

2009-05-15

57

Conducting a Teaching Experiment with a Gifted Student  

ERIC Educational Resources Information Center

In this study, the teaching experiment methodology is used to observe firsthand a gifted student's mathematical learning and reasoning. A series of teaching experiments was conducted with 1 gifted and 1 average 7th-grade student to investigate how the gifted student's mathematical concepts and operation constructions differed from those of the…

Hekimoglu, Serkan

2004-01-01

58

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

59

Operational Amplifier Experiments for the Chemistry Laboratory.  

ERIC Educational Resources Information Center

Provides details of experiments that deal with the use of operational amplifiers and are part of a course in instrumental analysis. These experiments are performed after the completion of a set of electricity and electronics experiments. (DDR)

Braun, Robert D.

1996-01-01

60

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

SciTech Connect

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

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

1999-06-10

61

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

SciTech Connect

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

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

1999-06-01

62

Asteroid Regolith Mechanical Properties: Laboratory Experiments With Cohesive Powders  

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

63

49 CFR 40.89 - What is validity testing, and are laboratories required to conduct it?  

Code of Federal Regulations, 2010 CFR

...2010-10-01 2010-10-01 false What is validity testing, and are laboratories required to conduct it...PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Drug Testing Laboratories § 40.89 What is validity...

2010-10-01

64

Laboratory Experiments for Network Security Instruction  

ERIC Educational Resources Information Center

We describe a sequence of five experiments on network security that cast students successively in the roles of computer user, programmer, and system administrator. Unlike experiments described in several previous papers, these experiments avoid placing students in the role of attacker. Each experiment starts with an in-class demonstration of an…

Brustoloni, Jose Carlos

2006-01-01

65

A Modern Compressible Flow Laboratory Experience for Undergraduates  

E-print Network

measurements course is then followed consecutively by an aero-structures and an aerodynamics laboratory will have taken an incompressible aerodynamics course. They will be enrolled in the compressible aerodynamics course concurrently with the aerodynamics laboratory. Thus, a compressible laboratory experience

Texas at Arlington, University of

66

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

67

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

68

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

69

Astrophysical jets: Observations, numerical simulations, and laboratory experiments  

SciTech Connect

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

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

2009-04-15

70

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

71

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

72

Description of the Spacecraft Control Laboratory Experiment (SCOLE) facility  

NASA Technical Reports Server (NTRS)

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

Williams, Jeffrey P.; Rallo, Rosemary A.

1987-01-01

73

Description of the Spacecraft Control Laboratory Experiment (SCOLE) facility  

NASA Technical Reports Server (NTRS)

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

Williams, Jeffrey P.; Rallo, Rosemary A.

1987-01-01

74

Quantum Optics Experiments with Single Photons for Undergraduate Laboratories  

E-print Network

Quantum Optics Experiments with Single Photons for Undergraduate Laboratories Enrique J. Galvez of interference experiments for undergraduates that underscore the quantum nature of the light. The experiments use parametric down-conversion to generate pairs of correlated photons. The experiments involve one

Galvez, Enrique J. "Kiko"

75

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

76

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

SciTech Connect

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

Taylor, S.R.

1993-06-11

77

Colorimetric Titration Experiment for the Undergraduate Laboratory.  

ERIC Educational Resources Information Center

Describes a colorimetric titration instrument usable in the undergraduate laboratory that fulfills the objectives of ruggedness, freedom from ambient light interference, and low cost. Although accessories can be added (raising the price), the basic instrument is low priced and can be used manually with a simple voltmeter. (JN)

Lopez, Edwin; Vassos, Basil H.

1984-01-01

78

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.

79

Estimation on the self recovery behavior of low-conductivity layer in landfill final cover by laboratory conductivity tests.  

PubMed

This study examined the application of a Self Recovering Sustainable Layer (SRSL) as a landfill final cover. Low-conductivity layers in landfill covers are known to have problems associated with cracking as a result of the differential settlement or climatic changes. A SRSL is defined as a layer with chemical properties that reduces the increased hydraulic conductivity resulting from cracking by forming low-conductivity precipitates of chemicals contained in the layer. In this study, the formation of precipitates was confirmed using a batch test, spectroscopic analysis and mineralogical speciation tests. The possibility of secondary contamination due to the chemicals used for recovery was evaluated using a leaching test. A laboratory conductivity test was performed on a single layer composed of each chemical as well as on a 2-layer system. The recovery performance of the SRSL was estimated by developing artificial cracks in the specimens and observing the change in hydraulic conductivity as a function of time. In the laboratory conductivity test, the hydraulic conductivity of a 2-layer system as well as those of the individual layers that comprise the 2-layer system was estimated. In addition sodium ash was found to enhance the reduction in conductivity. A significant increase in conductivity was observed after the cracks developed but this was reduced with time, which indicated that the SRSL has a proper recovering performance. In conclusion, a SRSL can be used as a landfill final cover that could maintain low-conductivity even after the serious damages due to settlement. PMID:17203605

Kwon, O; Park, J

2006-11-01

80

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

81

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

82

New (Internal) Wave Generation - Laboratory Experiments  

Microsoft Academic Search

In this fluid dynamics video, we demonstrate the experimental generation of various internal wave fields using a novel wave generator. Specifically, uni-directional internal wave beams and vertical modes 1 and 2 are generated and visualized using Particle Image Velocimetry. Further details and analysis of these experiments can be found in [1].

Manikandan Mathur; Matthieu Mercier; Thierry Dauxois; Thomas Peacock

2009-01-01

83

"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

84

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

85

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

86

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

ERIC Educational Resources Information Center

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

Ewing, Sheila

1982-01-01

87

Traditional Laboratory Exercises and Remote Experiments in Electrical Engineering Education  

Microsoft Academic Search

Laboratory work is recognized as an efficient method for students to assimilate knowledge and to develop skills for solving real world problems. The Internet provides new opportunities for remote experimentation. Laboratory exercises in electrical engineering courses such as circuit theory and basic electronics can be performed remotely using real equipment. What equipment is required for remote experiments? Is it possible

Ingvar Gustavsson

88

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

89

The value of laboratory experiments for code validations  

Microsoft Academic Search

The validation of numerical codes used for rock mechanics and rock engineering involves establishing whether the codes do indeed represent reality. This is difficult to establish using full-scale field tests, and so initial validation using laboratory tests is recommended. In laboratory tests, the number of variables and the boundary conditions can be controlled. Good validation experiments will enhance confidence in

W. R Wawersik

2000-01-01

90

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...

91

Crepuscular rays: laboratory experiments and simulations.  

PubMed

Model simulations of laboratory-generated and natural crepuscular rays are presented. Rays are created in the laboratory with parallel light beams that pass through artificial fogs and milk-water solutions. Light scattered by 90° in a dilute mixture of whole milk first increases in intensity with distance from the source to a maximum as a result of multiple scattering by mainly small angles before decreasing exponentially due to extinction as distance continues to increase. Crepuscular rays are simulated for three cloud configurations. In case 1, the Sun at the zenith is blocked by a cloud with an overhanging anvil. The rays appear white against blue sky and are brightest when atmospheric turbidity, ??11. Shading by the anvil separates maximum brightness from apparent cloud edge. In case 2, a ray passes through a rectangular gap in a cloud layer. The ray is faint blue in a molecular atmosphere but turns pale yellow as ? and solar zenith angle, ?(sun), increase. At ?(sun)=60° it appears most striking when the cloud is optically thick, ??5, and the beam width ?x?1000 m. In these cases, increasing aerosol radius, r(aer), to about 1000 nm brightens, narrows, and shortens rays. In case 3, the twilight Sun is shaded by a towering cloud or mountain. The shaded rays are deeper blue than the sunlit sky because the light originates higher in the atmosphere, where short waves have suffered less depletion from scattering. The long optical path taken by sunlight at twilight makes color and lighting contrasts of the rays greatest when the air is quite clean, i.e., for ?-1?1. In all cases, the brightest rays occur when sunlight passes through an optical thickness of atmosphere, ??O(1). PMID:22016238

Gedzelman, Stanley David; Vollmer, Michael

2011-10-01

92

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

93

Comparing Volcano Infrasound and Aeroacoustics Laboratory Experiments  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

94

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

95

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...

96

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

97

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.

98

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

99

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

100

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...

101

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

102

Modeling Astrophysical Jets in a Laboratory Experiment  

NASA Astrophysics Data System (ADS)

We will present experimental results on formation of supersonic radiatively cooled plasma jets with dimensionless parameters (Mach number ˜20, cooling parameter ˜1 and density contrast ?j/?a ˜10) similar to those in proto-stellar jets. Two different experimental configurations are used. In the first the produced jets are purely hydrodynamic and are used to study deflection of the jets by the cross-wind. The ``cross wind'' leads to deflection of the jet through formation of internal oblique shocks in the jet and we will discuss the relevance of these observations to the astrophysical systems. In the second configuration the jets have toroidal magnetic field and the plasma beta in these jets is of the order of unity. We will present experimental data on the dynamics of ``magnetic bubble'' surrounding the jet and on the development of m=0,1 instabilities in the jet. Although at later times the jet column is observed to go unstable, we observe that the jet retains its collimation. Modifications of the experimental configuration allowing addition of the poloidal magnetic field and angular momentum to the jet will be also discussed. The experiments are scalable to astrophysical flows in that critical dimensionless numbers such as the plasma collisionality, the plasma beta and the magnetic Reynolds number are all in the astrophysically appropriate ranges. In collaboration with A. Ciardi, D. Ampleford, S.N. Bland, S.C. Bott, J.P. Chittenden, G. Hall, C. Jennings, J. Rapley A. Frank, E. G. Blackman, T. Lery.

Lebedev, Sergey

2006-04-01

103

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

104

Preparation of Buffers. An Experiment for Quantitative Analysis Laboratory  

NASA Astrophysics Data System (ADS)

In our experience, students who have a solid grounding in the theoretical aspects of buffers, buffer preparation, and buffering capacity are often at a loss when required to actually prepare a buffer in a research setting. However, there are very few published laboratory experiments pertaining to buffers. This laboratory experiment for the undergraduate quantitative analysis lab gives students hands-on experience in the preparation of buffers. By preparing a buffer to a randomly chosen pH value and comparing the theoretical pH to the actual pH, students apply their theoretical understanding of the Henderson-Hasselbalch equation, activity coefficients, and the effect of adding acid or base to a buffer. This experiment gives students experience in buffer preparation for research situations and helps them in advanced courses such as biochemistry where a fundamental knowledge of buffer systems is essential.

Buckley, P. T.

2001-10-01

105

Estimating sphagnum peat hydraulic properties from laboratory evaporation experiments  

NASA Astrophysics Data System (ADS)

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

Weber, Tobias K. D.; Durner, Wolfgang

2013-04-01

106

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

107

Laboratory Experiments to Stimulate CO(2) Ocean Disposal  

SciTech Connect

This Technical Progress Report summarizes activities conducted over the period 8/16/96-2/15/97 as part of this project. 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 is 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. Critical technical uncertainties of ocean disposal of CO{sub 2} will be addressed by performing experiments that: (1) characterize size spectra and velocities of a dispersed CO{sub 2} phase in the near-field of a discharge jet; and (2) estimate rates of mass transfer from dissolving droplets of liquid CO{sub 2} encased in a thin hydrate shell. Experiments will be conducted in a laboratory facility that can reproduce conditions in the ocean to depths of 600 m (1,969 ft). Between 8/16/96 and 2/15/97, activities focused on modifications to the experimental apparatus and the testing of diagnostics. Following completion of these tasks, experiments will be initiated and will continue through the end of the 36 month period of performance. Major accomplishments of this reporting period were: (1) delivery, set-up, and testing of the PDPA (Phase Doppler Particle Analyzer), which will be the principal diagnostic of the continuous CO{sub 2} jet injection tests; (2) presentation of research papers and posters at the 212th American Chemical Society National Meeting and the Third International Conference on Carbon Dioxide Removal; (3) participation in the 4th Expert Workshop on Ocean Storage of Carbon Dioxide; (4) execution of an Agreement with ABB Management, Ltd. to support and extend the activities of this grant; and (5) initiation of research collaborations with Dr. P.M. Haugen of the University of Bergen, Norway, and Dr. A. Yamasaki of the National Institute of Materials and Chemical Research, Japan.

Masutani, S.M.

1997-03-12

108

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

109

Argumentation in the Chemistry Laboratory: Inquiry and Confirmatory Experiments  

ERIC Educational Resources Information Center

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

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

2013-01-01

110

Development of sensorial experiments and their implementation into undergraduate laboratories  

NASA Astrophysics Data System (ADS)

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

Bromfield Lee, Deborah Christina

111

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

112

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

113

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

Code of Federal Regulations, 2013 CFR

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

2013-04-01

114

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

Code of Federal Regulations, 2011 CFR

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

2011-04-01

115

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

Code of Federal Regulations, 2010 CFR

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

2010-04-01

116

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

Code of Federal Regulations, 2012 CFR

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

2012-04-01

117

Forensics as a Laboratory Experience in Small Group Communication.  

ERIC Educational Resources Information Center

Forensics programs can be laboratories for small group processes, whether or not they are explicitly recognized by either the participants or their teachers. Small group dynamics, as identified by M. Shaw (1981), are present and clearly define the forensic activity as a small group experience. The combination of being a small group, spending…

Zeuschner, Raymond Bud

118

LABORATORY EXPERIMENT 5 PRECIPITATION TITRATION WITH SILVER NITRATE.  

E-print Network

, it is desirable to maintain the particles of silver chloride in the colloidal state. INDICATOR DichlorofluoresceinLABORATORY EXPERIMENT 5 PRECIPITATION TITRATION WITH SILVER NITRATE. The AgNO3 solution (~0.02 M surrounding the silver chloride and imparts color to the solid. To obtain a satisfactory color change

Nazarenko, Alexander

119

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 in the titration of chloride ion with silver nitrate. The first excess of titrant results in the formation of a red Ag2CrO4. Calculations: From the volume of silver nitrate solution used fopr titration, calculate

Nazarenko, Alexander

120

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

121

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

122

Science Education 490 Laboratory/Field Experience in Elementary Science  

E-print Network

will be explicitly related to the K-12 Next Generation Science Standards (NGSS) and the Washington State ScienceScience Education 490 Laboratory/Field Experience in Elementary Science When: Fall 2013 Where: Mon · Curriculum: You will adapt an assigned research-based curriculum to create a coherent science unit

Acevedo, Alejandro

123

The Design of "Smart" Water Market Institutions Using Laboratory Experiments  

E-print Network

as an analysis of market price volatility. The implications of this research extend well beyond California water research project "Environmental Change and Adaptive Resource Markets: Computer-Assisted Markets for WaterThe Design of "Smart" Water Market Institutions Using Laboratory Experiments James J. Murphy

Murphy, James J.

124

Raising environmental awareness through applied biochemistry laboratory experiments.  

PubMed

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

Salman Ashraf, S

2013-01-01

125

A Mentoring Program with Hands-on Laboratory Experiments  

NSDL National Science Digital Library

This article describes a program in which middle-school girls are paired with women undergraduate science majors to carry out hands-on laboratory experiments that relate everyday life. The goal of this science mentoring program is to encourage middle-scho

Nancy E. Lee

1999-09-01

126

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

127

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

128

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

NSDL National Science Digital Library

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

Shaw, David

2012-05-29

129

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

130

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

Microsoft Academic Search

Three-layer monotonic electrical conductivity models for the lunar interior to a depth of 600 km are used in conjunction with laboratory measurements of the electrical conductivity of olivine and pyroxene to estimate a temperature-depth profile. The temperatures calculated for depths of 400-600 km are consistent with attenuation of the seismic shear wave. The temperature calculated at a depth of 100-250

C. P. Sonett; A. Duba

1975-01-01

131

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

NASA Technical Reports Server (NTRS)

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

1972-01-01

132

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

ERIC Educational Resources Information Center

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

Haystead, Mark W.; Marzano, Robert J.

2009-01-01

133

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 ...

134

Internal solitons in laboratory experiments: Comparison with theoretical models  

Microsoft Academic Search

Nonlinear internal solitary waves observed in laboratory experiments are discussed from the standpoint of their relation to different soliton theories, from the classical integrable models such as the Korteweg-de Vries, Gardner, Benjamin-Ono, and Joseph-Kubota-Ko-Dobbs equations and their modifications, through the nonintegrable models describing higher-order nonlinear effects, viscosity, rotation, and cylindrical spreading, to the strongly nonlinear models. First, these theoretical models

L. A. Ostrovsky; Y. A. Stepanyants

2005-01-01

135

Remote Sensing of Biologically Reworked Sediments: A Laboratory Experiment  

Microsoft Academic Search

The present study aims to test the application of remote sensing to address the impact of bioturbation on physical sediment\\u000a properties. Therefore, a laboratory experiment was developed, using microcosms mimicking a marine intertidal water–sediment\\u000a interface to test the influence of Corophium volutator densities on sediment properties. Three main variables (water content, clay content, and mean grain size) were measured in

Annelies De Backer; Stefanie Adam; Jaak Monbaliu; Erik Toorman; Magda Vincx; Steven Degraer

2009-01-01

136

Laboratory Flume Experiment with a Coded Structured Light System  

NASA Astrophysics Data System (ADS)

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

Akca, D.; Seybold, H.

2012-07-01

137

Numerical experiments using hierarchical finite element method for nonlinear heat conduction in plates  

E-print Network

Numerical experiments using hierarchical finite element method for nonlinear heat conduction hierarchical finite element method for heat conduction problems over two- or three-dimensional plates. Problems considered are nonlinear because the heat conductivity parameter depends upon the temperature itself

Kaneko, Hideaki

138

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

139

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

PubMed Central

Electrothermal flow is a promising technique in microfluidic manipulation toward laboratory automation applications, such as clinical diagnostics and high throughput drug screening. Despite the potential of electrothermal flow in biomedical applications, relative little is known about electrothermal manipulation of highly conductive samples, such as physiological fluids and buffer solutions. In this study, the characteristics and challenges of electrothermal manipulation of fluid samples with different conductivities were investigated systematically. Electrothermal flow was shown to create fluid motion for samples with a wide range of conductivity when the driving frequency was above 100 kHz. For samples with low conductivities (below 1 S/m), the characteristics of the electrothermal fluid motions were in quantitative agreement with the theory. For samples with high conductivities (above 1 S/m), the fluid motion appeared to deviate from the model as a result of potential electrochemical reactions and other electrothermal effects. These effects should be taken into consideration for electrothermal manipulation of biological samples with high conductivities. This study will provide insights in designing microfluidic devices for electrokinetic manipulation of biological samples toward laboratory automation applications in the future. PMID:21180401

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

2010-01-01

140

The Heavy Photon Search experiment at Jefferson Laboratory  

SciTech Connect

The Heavy Photon Search experiment (HPS) at Jefferson Laboratory will search for a new U(1) massive gauge boson, or "heavy-photon", mediator of a new fundamental interaction, called "dark-force", that couples to ordinary photons through kinetic mixing. HPS has sensitivity in the mass range 20 MeV – 1 GeV and coupling epsilon2 between 10?5 and 10?10. The HPS experiment will look for the e+e? decay of the heavy photon, by resonance search and detached vertexing, in an electron beam fixed target experiment. HPS will use a compact forward spectrometer, which employs silicon microstrip detectors for vertexing and tracking, and a PbWO4 electromagnetic calorimeter for energy measurement and fast triggering.

Celentano, Andrea [INFN-GENOVA

2014-11-01

141

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

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

142

Inter-Laboratory Uranium Double-Spike Experiment  

SciTech Connect

In environmental samples, the major analytical limitation on the use of uranium {sup 238}U/{sup 235}U determinations as an indicator of uranium enrichment is mass dependent bias occurring during the measurement. The double-spike technique can be used to correct the data for this effect. The purpose of this experiment was to evaluate the variation of mass bias among several laboratories and to determine the extent to which the double-spike could be used to reduce analytical uncertainty. Four laboratories performed replicate analyses on each of three samples. Generally mass bias was determined to be small compared to the random scatter of the measurements, but in at least one case, the bias was > 1%. In 8 of 12 cases, intra-laboratory variance was reduced when the double-spike correction was applied. For all three samples, the inter-laboratory variance was decreased, though the decrease was small. Based on a reasonable assumption about the true isotopic compositions of the samples, the accuracy of 11 of the twelve analyses was improved by applying the double spike correction. When the double spike is used to correct for mass bias, the {sup 238}U/{sup 235}U accuracy is better than 1% even for samples as small as 1 ng. For 50 ng of uranium, 0.1% accuracy was achieved.

Russ, G. P

1999-11-11

143

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

144

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

145

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

NASA Technical Reports Server (NTRS)

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

Sonett, C. P.; Duba, A.

1975-01-01

146

Modeling Laser-Driven Laboratory Astrophysics Experiments Using the CRASH Code  

NASA Astrophysics Data System (ADS)

Laser-driven, laboratory astrophysics experiments can provide important insight into the physical processes relevant to astrophysical systems. The radiation hydrodynamics code developed by the Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan has been used to model experimental designs for high-energy-density laboratory astrophysics campaigns on OMEGA and other high-energy laser facilities. This code is an Eulerian, block-adaptive AMR hydrodynamics code with implicit multigroup radiation transport and electron heat conduction. The CRASH model has been used on many applications including: radiative shocks, Kelvin-Helmholtz and Rayleigh-Taylor experiments on the OMEGA laser; as well as laser-driven ablative plumes in experiments by the Astrophysical Collisionless Shocks Experiments with Lasers (ACSEL) collaboration. We report a series of results with the CRASH code in support of design work for upcoming high-energy-density physics experiments, as well as comparison between existing experimental data and simulation results. This work is funded by the Predictive Sciences Academic Alliances Program in NNSA-ASC via grant DEFC52- 08NA28616, by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-FG52-09NA29548, and by the National Laser User Facility Program, grant number DE-NA0000850.

Grosskopf, Michael; Keiter, P.; Kuranz, C. C.; Malamud, G.; Trantham, M.; Drake, R.

2013-06-01

147

Thermal conductivity of polycrystalline CVD diamond: Experiment and theory  

NASA Astrophysics Data System (ADS)

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

Inyushkin, A. V.; Taldenkov, A. N.; Ral'Chenko, V. G.; Konov, V. I.; Khomich, A. V.; Khmel'Nitski?, R. A.

2008-09-01

148

The invaluable experience of conducting undergraduate research provides skills,  

E-print Network

traffic on dolphin populations. From this experience, Clarry learned the value of "study by doing," which to his lab work in neurobiology and behavior. 26 Unparalleled Experiences Butterfly and Mosquito Research behavior. Postdoc Maria del Campo and Eisner helped Clarry to shape her ideas into a project on the flight

Wang, Z. Jane

149

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

150

Laboratory experiments and Shock Breakout Probes of the Early Universe  

NASA Astrophysics Data System (ADS)

Our understanding of the first epoch of star formation has been limited by the lackof quality data of the early universe. The deaths of massive stars (supernovae, gamma-ray bursts, pair instability supernovae) may provide key information into this early stage in the evolution of the universe. In the nearby universe, observations of shock breakout, when observed, have provided vital clues into the engine behind these cosmic explosions. Shock breakout is the astronomy term for the condition where the radiation in the shock becomes optically thin and can escape. Modeling shock breakout requires true radiation-hydrodynamics calculations and tests our algorithms for radiation transport. Because of redshift effects, shock breakout is the only "transient" observed in first-star supernovae. To trust the models of this important early universe probe, we must test our transport algorithms. We are currently using a number of laboratory experiments to test aspects of radiation hydrodynamics. Here I review the basic problem of shock breakout models of supernovae in the early universe, tying these probes to current and future laboratory experiments.

Fryer, Chris

2011-05-01

151

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

152

Kinetics of Papain: An Introductory Biochemistry Laboratory Experiment  

NASA Astrophysics Data System (ADS)

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

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

1999-05-01

153

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

154

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

155

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

156

The conducted action potential. Models and comparison to experiments.  

PubMed Central

Propagation of the action potential is a complex process, and the relationships among the various factors involved in conduction have not been clear. We use three mathematical models of uniform conduction in a cable to clarify some of these relationships. One model is newly derived here, and two have been previously derived by Hunter et al. (1975, Prog. Biophys. Mol. Biol., 30:99-144). These models were able to simulate individual experimental action potential upstrokes previously obtained (Walton and Fozzard, 1983, Biophys. J., 44:1-8). The models were then utilized to provide relationships between measures of conduction. Among these were that maximal upstroke velocity (Vmax) is directly proportional to peak inward ionic current normalized by capacitance that is filled during the upstroke (I/Cf), and that conduction velocity was directly related to the square root of either Vmax or I/Cf. These relationships were shown to be model independent and to predict the experimental results, thus providing validated quantitative relationships that were not discernible through use of experimental data alone. The concept of safety factor was considered and a parameter was proposed that may be related to safety factor. PMID:6626682

Walton, M K; Fozzard, H A

1983-01-01

157

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

158

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

159

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

160

The Software Engineering Laboratory: An operational software experience factory  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

161

Scaled Laboratory Collisionless Shock Experiments in the Large Plasma Device  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

162

Mission Specialist (MS) Allen conducts Vestibular Study Experiment on middeck  

NASA Technical Reports Server (NTRS)

Mission Specialist (MS) Allen, wearing headset and with electrodes placed on his face, relaxes on middeck floor while Vestibular Study Experiment hardware records eye movement data as it relates to motion sickness. The electrodes monitor his responses in zero gravity. Allen is wearing the multi-pieced constant wear garment.

1982-01-01

163

Slew maneuvers of Spacecraft Control Laboratory Experiment (SCOLE)  

NASA Technical Reports Server (NTRS)

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

Kakad, Yogendra P.

1992-01-01

164

Intelligent Experiment Design-Based Virtual Remote Sensing Laboratory  

NASA Astrophysics Data System (ADS)

We address unified intelligent descriptive experiment design regularization (DEDR) methodology for computer-aided investigation of new intelligent signal processing (SP) perspectives for collaborative remote sensing (RS) and distributed sensor network (SN) data acquisition, intelligent processing and information fusion. The sophisticated "Virtual RS Laboratory" (VRSL) software elaborated using the proposed DEDR methodology is presented. The VRLS provides the end-user with efficient computational tools to perform numerical simulations of different RS imaging problems. Computer simulation examples are reported to illustrate the usefulness of the elaborated VRSL for the algorithmic-level investigation of high-resolution image formation, enhancement, fusion and post-processing tasks performed with the artificial and real-world RS imagery.

Shkvarko, Yuriy; Santos, Stewart; Tuxpan, Jose

165

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

166

Advanced laboratory experiences that impact lives: student and faculty perspectives  

NASA Astrophysics Data System (ADS)

How can one best stimulate and nourish those significant laboratory experiences with students that can ``light a fire?''^1 Students are quick to detect when novel and interesting approaches to apparatus, procedure, and analysis are sought and anticipated, and it can radically change the ``What do you want us to do next?'' atmosphere that sometimes is present in either introductory or advanced labs. While a spirit of research may be difficult or disingenuous to seek for some rather constrained advanced lab exercises, it should surely be laid-out as a desired outcome for more open-ended projects. In optical physics and metrology (Fourier optics, Faraday effect, sonoluminescence, high-speed interferometry, Schlieren, and holographic measurements), I will highlight several engaging examples where student driven experimental physics has blossomed within our advanced labs, and subsequently morale and career choices have been impacted. ^1W. B. Yeats, ``Education is not the filling of a pail, but the lighting of a fire.''

Peterson, Richard

2007-10-01

167

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

168

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

169

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

170

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

171

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

172

Electric Conduction in Solids: a Pedagogical Approach Supported by Laboratory Measurements and Computer Modelling Environments  

NASA Astrophysics Data System (ADS)

In this paper we present a pedagogic approach aimed at modeling electric conduction in semiconductors, built by using NetLogo, a programmable modeling environment for building and exploring multi-agent systems. `Virtual experiments' are implemented to confront predictions of different microscopic models with real measurements of electric properties of matter, such as resistivity. The relations between these electric properties and other physical variables, like temperature, are, then, analyzed.

Bonura, A.; Capizzo, M. C.; Fazio, C.; Guastella, I.

2008-05-01

173

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

NASA Technical Reports Server (NTRS)

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

1972-01-01

174

The Naval Research Laboratory's Air-Sea Interaction Blimp Experiment.  

NASA Astrophysics Data System (ADS)

The rationale is given for a unique experiment in which microwave scatterometer and surface flux measurements are to be made from a blimp to develop an improved scatterometer model function. A principal goal of the effort is to obtain a more accurate understanding of the relationship between the surface fluxes and the microwave power backscattered from the surface of the ocean. The limitations of previous overwater surface flux and scatterometer measurements are reviewed. The accuracy of various flux measurement techniques are compared. Evidence shows that if direct surface flux measurements are to be accurate to better than 20%, the measurements should be made at an altitude of about 5 m to 10 m from a platform that is free of flow distortion. The improved surface flux measurements are required to test proposed scatterometer theories and to determine whether the radar backscatter is principally a function of surface stress or wind speed. It is concluded that scatterometer measurements accompanied by eddy-correlation technique flux measurements must be made from a platform that is highly mobile and which enables the measurements to be made over a variety of oceanic conditions. To meet these requirements, the Naval Research Laboratory is undertaking a series of air-sea interaction experiments in which a sonic anemometer and other flux measurement instrumentation are suspended 60 m beneath a blimp flying at an altitude of 70 m while multiple scatterometer measurements are made from the blimp's gondola. Experiments are planned for a wide range of oceanic environments beginning off the central east coast of the United States in 1990.

Blanc, Theodore V.; Plant, William J.; Keller, William C.

1989-04-01

175

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

176

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

177

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

178

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

NASA Technical Reports Server (NTRS)

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

Woike, Mark R.; Abdul-Aziz, Ali

2010-01-01

179

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

180

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

181

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

182

Control of Spacecraft Control Laboratory Experiment (SCOLE) slew maneuvers  

NASA Technical Reports Server (NTRS)

This is the second report of a set of two reports on the dynamics and control of slewing maneuvers of NASA Spacecraft Control Laboratory Experiment (SCOLE). The control problem of slewing maneuvers of SCOLE is developed in terms of an arbitrary maneuver about any given axis. The control system is developed for the combined problem of rigid-body slew maneuver and vibration suppression of flexible appendage. The control problem is formulated by incorporating the nonlinear equations derived in the previous report and is expressed in terms of a two-point boundary value problem utilizing a quadratic type of performance index. The two-point boundary value problem is solved as a hierarchical control problem with the overall system being split in terms of two subsystems, namely the slewing of the entire assembly and the vibration suppression of the flexible antenna. The coupling variables between the two dynamical subsystems are identified and these two subsystems for control purposes are treated independently in parallel at the first level. Then the state-space trajectory of the combined problem is optimized at the second level.

Kakad, Y. P.

1987-01-01

183

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

184

Three-dimensional Simulation of Gas Conductance Measurement Experiments on Alcator C-Mod  

SciTech Connect

Three-dimensional Monte Carlo neutral transport simulations of gas flow through the Alcator C-Mod subdivertor yield conductances comparable to those found in dedicated experiments. All are significantly smaller than the conductance found with the previously used axisymmetric geometry. A benchmarking exercise of the code against known conductance values for gas flow through a simple pipe provides a physical basis for interpreting the comparison of the three-dimensional and experimental C-Mod conductances.

D.P. Stotler; B. LaBombard

2004-06-15

185

Practice-based research networks (PBRNs) are promising laboratories for conducting dissemination and implementation research.  

PubMed

Dissemination and implementation science addresses the application of research findings in varied health care settings. Despite the potential benefit of dissemination and implementation work to primary care, ideal laboratories for this science have been elusive. Practice-based research networks (PBRNs) have a long history of conducting research in community clinical settings, demonstrating an approach that could be used to execute multiple research projects over time in broad and varied settings. PBRNs also are uniquely structured and increasingly involved in pragmatic trials, a research design central to dissemination and implementation science. We argue that PBRNs and dissemination and implementation scientists are ideally suited to work together and that the collaboration of these 2 groups will yield great value for the future of primary care and the delivery of evidence-based health care. PMID:25381072

Heintzman, John; Gold, Rachel; Krist, Alexander; Crosson, Jay; Likumahuwa, Sonja; DeVoe, Jennifer E

2014-01-01

186

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

187

Ten Years' Experience in Running a Pulmonary Function Laboratory  

PubMed Central

A survey of the development and work of a pulmonary function laboratory in a teaching hospital over a 10-year period has shown an increasing demand for pulmonary function tests from all departments, in particular some of the surgical ones. Though no arrangement for staffing and equipping such a laboratory is ideal quite a lot of useful clinical information can be derived from a few simple tests performed in a central laboratory. PMID:4653878

Hughes, D. T. D.; Empey, D. W.

1972-01-01

188

Identification of vortexes obstructing the dynamo mechanism in laboratory experiments  

NASA Astrophysics Data System (ADS)

The magnetohydrodynamic dynamo effect explains the generation of self-sustained magnetic fields in electrically conducting flows, especially in geo- and astrophysical environments. Yet the details of this mechanism are still unknown, e.g., how and to which extent the geometry, the fluid topology, the forcing mechanism, and the turbulence can have a negative effect on this process. We report on numerical simulations carried out in spherical geometry, analyzing the predicted velocity flow with the so-called singular value decomposition, a powerful technique that allows us to precisely identify vortexes in the flow which would be difficult to characterize with conventional spectral methods. We then quantify the contribution of these vortexes to the growth rate of the magnetic energy in the system. We identify an axisymmetric vortex, whose rotational direction changes periodically in time, and whose dynamics are decoupled from those of the large scale background flow, that is detrimental for the dynamo effect. A comparison with experiments is carried out, showing that similar dynamics were observed in cylindrical geometry. These previously unexpected eddies, which impede the dynamo effect, offer an explanation for the experimental difficulties in attaining a dynamo in spherical geometry.

Limone, A.; Hatch, D. R.; Forest, C. B.; Jenko, F.

2013-06-01

189

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

190

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

191

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

192

Estimating unsaturated soil hydraulic properties from laboratory tension disc infiltrometer experiments  

NASA Astrophysics Data System (ADS)

Four tension disc infiltration experiments were carried out on a loamy soil in the laboratory for the purpose of estimating the unsaturated soil hydraulic properties. Sixteen tensiometers were installed in pairs at the following coordinate (r,z) positions: (10, 2.5), (10, 5), (10, 10), (15, 5), (15, 10), (15, 15), (15, 20), and (15, 30), where r represents the distance from the axis of symmetry and z is the location below the soil surface. A time domain reflectometry (TDR) probe was used to measure water contents at a depth of 2 cm directly below the tension disc. The first three experiments involved supply pressure heads at the disc of -20, -10, -5, and -1 cm, with the experiment lasting for ~5 hours. The same supply pressure heads were also used for the fourth experiment, which lasted 6.25 days so as to reach steady state at each applied tension. The measured data were analyzed using Wooding's [1968] analytical solution and by numerical inversion. The parameter estimation method combined a quasi three-dimensional numerical solution of the Richards equation with the Marquardt-Levenberg optimization scheme. The objective function for the parameter estimation analysis was defined using different combinations of the cumulative infiltrated volume, TDR readings, and tensiometer measurements. The estimated hydraulic properties were compared against results obtained with an evaporation experiment as analyzed with Wind's [1968] method. Water contents in the retention curves were underestimated when both transient and quasi steady state experiments were analyzed by parameter estimation. Unsaturated hydraulic conductivities obtained by parameter estimation and using Wooding's [1968] analysis corresponded well. Drying branches of the hydraulic conductivity function determined by parameter estimation also corresponded well with those obtained with the evaporation method.

Šim?nek, Ji?í; Wendroth, Ole; van Genuchten, Martinus T.

1999-10-01

193

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

194

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

ERIC Educational Resources Information Center

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

Elkins, Kelly M.

2011-01-01

195

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

196

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

197

Fluorescence quantum yield measurements of fluorescent proteins: A laboratory experiment for a biochemistry or molecular biophysics laboratory course.  

PubMed

Fluorescent proteins are commonly used in cell biology to assess where proteins are within a cell as a function of time and provide insight into intracellular protein function. However, the usefulness of a fluorescent protein depends directly on the quantum yield. The quantum yield relates the efficiency at which a fluorescent molecule converts absorbed photons into emitted photons and it is necessary to know for assessing what fluorescent protein is the most appropriate for a particular application. In this work, we have designed an upper-level, biochemistry laboratory experiment where students measure the fluorescence quantum yields of fluorescent proteins relative to a standard organic dye. Four fluorescent protein variants, enhanced cyan fluorescent protein (ECFP), enhanced green fluorescent protein (EGFP), mCitrine, and mCherry, were used, however the methods described are useful for the characterization of any fluorescent protein or could be expanded to fluorescent quantum yield measurements of organic dye molecules. The laboratory is designed as a guided inquiry project and takes two, 4 hr laboratory periods. During the first day students design the experiment by selecting the excitation wavelength, choosing the standard, and determining the concentration needed for the quantum yield experiment that takes place in the second laboratory period. Overall, this laboratory provides students with a guided inquiry learning experience and introduces concepts of fluorescence biophysics into a biochemistry laboratory curriculum. © 2014 by The International Union of Biochemistry and Molecular Biology, 43(1):52-59, 2015. PMID:25395254

Wall, Kathryn P; Dillon, Rebecca; Knowles, Michelle K

2015-01-01

198

Combining Laboratory Experiments with Digital Tools to Do Scientific Inquiry  

ERIC Educational Resources Information Center

This qualitative study investigates the gap between a lab experiment and theory of science. Two groups of 4 students in 2 different classes in 11th grade (15-16 years old) are followed as they process results and experiences from a lab experiment using a digital environment. The experiment is as a part of a larger project about genes and cells,…

Kluge, Anders

2014-01-01

199

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

Microsoft Academic Search

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

Kapil K Goyal; David M French; Betty J Humphrey; Jeffry Gluth

2010-01-01

200

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

201

Resource Letter EMAA-2: Laboratory Experiences for Elementary Astronomy  

ERIC Educational Resources Information Center

This article provides resource materials teaching astronomy. Included are references to laboratory manuals, articles, films, telescopes, handbooks, and atlases. Each reference is classified as elementary, intermediate or advanced. (SL)

Kruglak, Haym

1976-01-01

202

Insights from laboratory experiments into the physics of pyroclastic flows  

NASA Astrophysics Data System (ADS)

We studied the transport and sedimentation behavior of rapid shear flows of gas-fluidized volcanic ash in a laboratory flume in order to better understand the kinematics of pyroclastic flows. The work was based on a previous study in which we explored the fluidization and settling behaviour of ash under quasi-static conditions in a 1-D high-temperature fluidization rig. Provided that temperature is high enough (>150 °C) to significantly reduce cohesion, ash fractions of pyroclastic flow deposits fluidize in the manner of Geldart group-A powders, with large expansions in the non-bubbling regime. When the flux of fluidizing gas is removed, the ash re-sediments by hindered settling at rates which, for a given material, are independent of temperature up to 550 °C. Armed with this knowledge, we built a 3-m-long lock-exchange flume in which we generated horizontal flows of fluidized ash. The ash was first placed in the flume reservoir, heated to 180 °C and expanded by gas flow up to 45 % above loose packing. It was then released down the flume and allowed to defluidize freely. The resulting flows were filmed at high speed, and the films were then analyzed visually and using a particle-tracking algorithm. The flows were typically several cm thick, had frontal speeds of up to ~2 m s-1, and were non-turbulent on scales larger than the constituent particles. Since the settling behavior of quasi-static ash is temperature independent, we expect the same to be true for flowing ash. Deposition took place progressively during transport until the flow was entirely consumed and motion ceased. It commenced 5-20 cm rearward of the leading edge and (for a given expansion) proceeded at a rate independent of distance from the lock gate. Deposit aggradation velocities were equal to those inferred beneath quasi-static bed collapse tests of the same ash at the same initial expansions, showing that shear rates of up to ~300 s-1 have no measurable effect on aggradation rate. Initially non-expanded (but just fluidized) ash deposited progressively at a rate indicative of an expansion of a few percent, perhaps due to Reynolds dilation during initial slumping. These behaviors have subsequently been confirmed by similar experiments using industrial group-A cracking catalyst powders instead of ash, and the combined results collapse to reveal a very simple scaling for the runout durations of the flows. Velocity profiles in the ash flows reveal that the frontal regions slid across the flume floor on very thin basal shear layers, implying high basal stresses, but that once sedimentation commenced, a no-slip condition was established at the depositional interface. The experiments show that even cm-thin, non-turbulent and poorly expanded flows of ash deposit progressively, as inferred for many pyroclastic flows. This raises the possibility that deposit aggradation rates in mathematical models of dense pyroclastic flows could be parameterized using values measured using 1D rigs. High frontal stresses are consistent with the occurrence of scour surfaces at the bases of some pyroclastic flow deposits.

Girolami, L.; Druitt, T. H.; Roche, O.

2009-12-01

203

The effects of laboratory-based and field-based practicum experience on pre-service teachers' self-efficacy  

Microsoft Academic Search

A well defined line of research has been conducted on the role of self-efficacy (Bandura, A. (1977). Self-efficacy: toward a unifying theory of behavioral change. Psychological Review, 84, 191–215.) in teaching and learning environments. The purpose of this study was to examine the effect of Laboratory-Based (LB) and Field-Based (FB) practicum experience on pre-service teachers' efficacy levels within one Physical

Rachel Gurvitch; Michael W. Metzler

2009-01-01

204

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

SciTech Connect

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

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

2011-04-05

205

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

206

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

207

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

ERIC Educational Resources Information Center

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

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

2004-01-01

208

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

209

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

210

Laboratory and Field Experiments on Expulsion of Selected Ions along Divergent Polar Geomagnetic Fields  

Microsoft Academic Search

Laboratory and Field Experiments on Expulsion of Selected Ions along Divergent Polar Geomagnetic Fields. Laboratory experiments have shown significant gyro-resonance acceleration of minority ion species in a magnetized plasma. Field aligned elctron drifts can provide free energy needed to make this process efficient. The linear magnetized device has a uniform magnetic field linked to two adjustable mirrors at the ends.

A. Y. Wong; B. Deng; B. Quon; R. Wang; J. Hartzell; G. Rosenthal; L. R. Hazelton

2007-01-01

211

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

212

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

213

Laser wavefront propagation through turbulent separated shear layers: laboratory experiments, computations, and physical modeling  

NASA Astrophysics Data System (ADS)

Laboratory experiments, computations, and physical modeling of laser wavefronts propagating through variable-refractive-index separated shear layers at large Reynolds numbers are conducted in order to examine the relation between the flow behavior and the laser wavefront behavior for airborne laser communications. The new element of this work is the focus on the dependence on scale of the optical behavior as well as of the flow behavior, using multiresolution analysis of the measured and computed data. The experiments are conducted using the UC Irvine variable-pressure turbulent flow facility. Direct non-intrusive imaging of the refractive index field is accomplished with laser-induced fluorescence and a high-resolution digital camera that resolves three decades of scales. Simultaneously, direct imaging of the propagated laser wavefront phase profile is conducted using a Shack-Hartmann array sensor that also has a resolution of three decades of scales. The computational component consists of near-field wavefront propagation through the measured refractive index field, validated by the direct wavefront measurements. We have conducted multiresolution analysis of the flow data and optical data, by a posteriori reducing the resolution of the refractive-index field and phase field. We present evidence of strong scale dependence at large scales, i.e. in the energy-containing range of scales. Physical modeling of this behavior is developed based on the structure of the coarse-grained refractive turbulent interfaces. This approach is useful in order to relate the root-mean-squared optical path difference and Strehl ratio, at variable resolutions, to the refractive-index variations along the laser wavefront propagation path. This facilitates the identification of the dominant refractive interfaces and serves as a guide to developing aero-optical optimization methods for airborne laser communication applications.

Zubair, Fazlul R.; Salvans-Tort, Josep; Piatrovich, Siarhei; Gwozdz, David W.; Freeman, Aaron P.; Shockro, Jennifer; Garcia, Philip J.; Nathman, Jennifer C.; Catrakis, Haris J.

2006-09-01

214

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

215

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

216

Laboratory experiments on turbulent mixing across sheared density interfaces  

NASA Astrophysics Data System (ADS)

An experimental study was carried out to investigate turbulent mixing and entrainment across a density interface subjected to velocity shear. The flow configuration consisted of a salinity (stably) stratified two-fluid system with a driven upper turbulent layer and a quiescent lower layer. The experiments were performed in an Odell-Kovasznay tank and the mean flow in the upper layer was generated by using a conventional disk pump. The velocity and salinity measurements were made using a laser-Doppler anemometer and conductivity probes, respectively, and (quantitative) flow visualization was performed using the laser-induced fluorescence LIF technique. The refractive indices of upper and lower layers were matched, using salt and alcohol, to facilitate the use of laser-based flow diagnostic techniques. The measurements show that the rms velocity fluctuation u in bulk of the mixed layer scales well with the mean velocity jump ?u across the interface. The Thorpe, buoyancy, overturning, and integral length scales, as well as the maximum Thorpe displacement in the mixed layer, were also found to be proportional to the depth h of the upper mixed layer. The structure of the entrainment interface was found to depend strongly on the bulk Richardson number Ri (=?b h/u2), where ?b is the buoyancy jump across the interfacial layer. At lower Ri, the entrainment occurred rapidly, as in a nonstratified fluid, but as Ri increases, the entrainment rate becomes a strong function of Ri: under the latter conditions, the interfacial wave breaking and Kelvin-Helmholtz instabilities were common features. At still higher Ri, the entrainment rate becomes vanishingly small and the interfacial mixing events were found to be controlled by the molecular diffusive effects. The measurement of the interfacial-layer thickness using LIF shows that it is much thinner than that measured using less-accurate techniques such as traversing probes. The nondimensional rms amplitude of the interfacial distortions at moderate and high Ri was found to be a strong function of Ri. The interfacial instabilities cause the formation of isolated mixing patches within the interface, which, when collapsed, form horizontal intrusions. The experimental measurements were in agreement with theoretical formulations based on scaling arguments.

Stephenson, Philip; Fernando, Harindra J. S.

1991-05-01

217

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

NASA Astrophysics Data System (ADS)

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

Judge, A. I.

2011-12-01

218

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

219

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

220

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

2011-04-22

221

Investigation on the Performance of Fire Detection Systems for Tunnel Applications––Part 1: Full-Scale Experiments at a Laboratory Tunnel  

Microsoft Academic Search

A two-year international road tunnel fire detection research project (Phase II) was completed recently. As part of this project,\\u000a a series of fire tests were conducted in a laboratory tunnel facility under minimum and longitudinal airflow conditions. In\\u000a addition, fire tests were also conducted in the Carré-Viger tunnel in Montreal. This paper presents the results of the full-scale\\u000a experiments conducted

Z. G. Liu; A. H. Kashef; G. D. Lougheed; G. P. Crampton

2011-01-01

222

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

223

Interactive Screen Experiments--Innovative Virtual Laboratories for Distance Learners  

ERIC Educational Resources Information Center

The desirability and value of laboratory work for physics students is a well-established principle and issues arise where students are inherently remote from their host institution, as is the case for the UK's Open University. In this paper, we present developments from the Physics Innovations Centre for Excellence in Teaching and Learning…

Hatherly, P. A.; Jordan, S. E.; Cayless, A.

2009-01-01

224

Equipment qualification testing evaluation experiences at Sandia National Laboratories  

Microsoft Academic Search

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

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

1986-01-01

225

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

ERIC Educational Resources Information Center

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

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

2007-01-01

226

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

227

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

228

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

229

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

230

A Thin Layer Chromatography Laboratory Experiment of Medical Importance  

ERIC Educational Resources Information Center

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

Sharma, Loretta; Desai, Ankur; Sharma, Ajit

2006-01-01

231

Touring the Tomato: A Suite of Chemistry Laboratory Experiments  

PubMed Central

An eight-session interdisciplinary laboratory curriculum has been designed using a suite of analytical chemistry techniques to study biomaterials derived from an inexpensive source such as the tomato fruit. A logical progression of research-inspired laboratory modules serves to “tour” the macroscopic characteristics of the fruit and the submicroscopic properties of its constituent cuticular biopolymers by atomic force microscopy (AFM), UV–visible, and nuclear magnetic resonance (NMR) methods at increasingly detailed molecular levels. The modular curriculum can be tailored for specialty undergraduate courses or summer high school workshops. By applying analytical tools to investigate biopolymers, making connections between molecular and microscale structure, and linking both structural regimes to the functional properties of natural polymers, groundwork is established for further student investigations at the interface of chemistry with biology or chemical engineering. PMID:23526490

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

2013-01-01

232

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

233

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

234

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

235

Sand bar beach stability under river stage fluctuations, full-scale laboratory experiments  

NASA Astrophysics Data System (ADS)

This research examines slope failure and seepage erosion of sand bar beaches due to rapid fluctuations in river stage. River engineering structures sometimes produce rapid stage fluctuations, especially hydroelectric dams used to supply electricity at peak demand. During a rapid drawdown in river stage, the groundwater level in the banks and exposed bars becomes higher than the river stage. Thus, pore water pressures in the banks and bars becomes elevated, possibly causing failure of bar or bank faces. As well, exfiltrating groundwater can cause seepage erosion. In this study we are focused on simulating the fluctuating stages in sandbar beaches in Grand Canyon on the Colorado River downstream of Glen Canyon Dam. Maximal downramp and upramp rates have been imposed on Glen Canyon dam operations. However, little is known about whether these imposed rates are necessary or sufficient. A full-scale physical model of a two-dimensional beach face (8 m long, 2.5 m high and 0.5 m wide) was constructed for the experiments. River stage and groundwater fluctuations can be simulated in this beach stability slot. We present data from multiple laboratory experiments measuring: (1) soil characteristics, establishing similitude with sandbar parameters in the field, (2) differential mass soil failure at fine time resolution, estimated as bar displacement using string potentiometers, (3) topographic profile at initial and final conditions and (3) piezometric head along the beach profile. In the laboratory we replicate a range of stage and groundwater fluctuations which occur, or could occur, in Grand Canyon. These scenarios incorporate US Geological Survey field measurements of river discharge and stage, phreatic surface, and sandbar bathymetry. We also test synthetic stage fluctuation scenarios. Experiments conducted at low (12 degree) slopes have shown significant seepage erosion at elevated groundwater levels scenarios leading to the presence of gullies and rills at the bar face. Contrastingly, experiments conducted on steep (26 degree) slopes have produced significant mass failures and still presence of seepage erosion at all tested stage fluctuations. In general, mass failure has been identified as the predominant process in degradation of steep beaches. These final products are critical to minimizing the mass loss during daily river fluctuations, building confidence on forecasting skill on river beaches failure models and facilitating the design of river restoration projects at the Colorado River.

Alvarez, L.; Schmeeckle, M.

2010-12-01

236

4,5-Diphenyl-1-methylimidazole: An Undergraduate Laboratory Experiment.  

ERIC Educational Resources Information Center

Background information and procedures used are provided for the synthesis of 4,5-diphenyl-methylimidazole. This experiment on the chemistry of heterocycles is ideally suited for beginning undergraduate organic chemistry students. (JN)

Anastas, Paul T.; And Others

1985-01-01

237

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

NASA Astrophysics Data System (ADS)

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

Voige, William H.

1997-08-01

238

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

239

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

240

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

241

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

ERIC Educational Resources Information Center

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

Nyasulu, Frazier; Stevanov, Kelly; Barlag, Rebecca

2010-01-01

242

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

243

A two-parameter nondiffusive heat conduction model for data analysis in pump-probe experiments  

NASA Astrophysics Data System (ADS)

Nondiffusive heat transfer has attracted intensive research interests in last 50 years because of its importance in fundamental physics and engineering applications. It has unique features that cannot be described by the Fourier law. However, current studies of nondiffusive heat transfer still focus on studying the effective thermal conductivity within the framework of the Fourier law due to a lack of a well-accepted replacement. Here, we show that nondiffusive heat conduction can be characterized by two inherent material properties: a diffusive thermal conductivity and a ballistic transport length. We also present a two-parameter heat conduction model and demonstrate its validity in different pump-probe experiments. This model not only offers new insights of nondiffusive heat conduction but also opens up new avenues for the studies of nondiffusive heat transfer outside the framework of the Fourier law.

Ma, Yanbao

2014-12-01

244

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

245

Savannah River Laboratory's operating experience with glass melters  

SciTech Connect

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

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

1982-01-01

246

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

Microsoft Academic Search

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

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

1996-01-01

247

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

248

Epigenetics of Complex Diseases: From General Theory to Laboratory Experiments  

Microsoft Academic Search

Despite significant effort, understanding the causes and mechanisms of complex non-Mendelian diseases remains a key challenge.\\u000a Although numerous molecular genetic linkage and association studies have been conducted in order to explain the heritable\\u000a predisposition to complex diseases, the resulting data are quite often inconsistent and even controversial. In a similar way,\\u000a identification of environmental factors causal to a disease is

A. Schumacher; A. Petronis

249

Experience in distributed parameter modeling of the Spacecraft Control Laboratory Experiment (SCOLE) structure  

NASA Technical Reports Server (NTRS)

The Spacecraft Control Laboratory Experiment (SCOLE) configuration is used to compare exact and approximate solutions of the partial differential equations which define its structural dynamics. The need for a proof model for evaluating competing control laws demands that solutions be generated which not only exhibit accurate modal characteristics, but precise static deflections as well. Because precise pointing is required, the motion of the end bodies of the Shuttle-attached antenna must be known with great accuracy. Modal models are attractive because of their stable solutions but require hundreds of modes to obtain a static deflection accuracy of only one percent. Although proportional damping in bending agrees well with experimental results using the SCOLE experimental apparatus, modes which involve both torsion and bending differ significantly from proportional damping. A lumped mass model is used to generate exact static deflections, but only approximate modal characteristics. Asymptotic solutions to the distributed parameter system approximate very accurately the modal characteristics at high mode numbers. Ways are examined for refining the approximate solutions by applying a first-order variation and by employing singular perturbation techniques which are usually limited to ordinary differential equations. The most accurate solutions of the distributed parameter model of SCOLE are obtained by combining exact and asymptotic solutions.

Taylor, L. W.; Naidu, D. S.

1987-01-01

250

Laboratory and telescope experiences with long optical fibre links  

Microsoft Academic Search

The installation at the (Coudé Echelle Spectrograph) of the new Short Camera coupled with an efficient CCD detector and the improvements on the spectral transmission of the commercially available fibres prompted a new experiment. The link was established between the Cassegrain focus of the 3.6 m and the CES. A change of fibres to take into account variable seeing conditions

G. Avila; S. D'Odorico

1988-01-01

251

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

252

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

253

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

ERIC Educational Resources Information Center

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

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

1980-01-01

254

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

ERIC Educational Resources Information Center

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

Turchi, Sandra L.; Weiss, Monica

1988-01-01

255

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

256

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

ERIC Educational Resources Information Center

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

Sotheeswaran, Subramaniam

1988-01-01

257

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

258

Effect of some amendments on leachate properties of a calcareous saline- sodic soil: A laboratory experiment  

NASA Astrophysics Data System (ADS)

Soil salinity and sodicity are escalating problems worldwide, especially in Iran since 90 percent of the country is located in arid and semi-arid. Reclamation of sodic soils involves replacement of exchangeable Na by Ca. While some researches have been undertaken in the controllable laboratory conditions using soil column with emphasis on soil properties, the properties of effluent as a measure of soil reclamation remain unstudied. In addition, little attention has been paid to the temporal variability of effluent quality. The objective of this study was to investigate the effect of different amendments consist of gypsum, manure, pistachio residue, and their combination for ameliorating a calcareous saline sodic soil. Temporal variability of effluent properties during reclamation period was studied, as well. A laboratory experiment was conducted to evaluate the effect of different amendments using soil columns. The amendment treatments were: control, manure, pistachio residue, gypsum powder (equivalent of gypsum requirement), manure+gypsum and pistachio residue+gypsum, which were applied once in the beginning of the experiment. The study was performed in 120 days period and totally four irrigation treatments were supplied to each column. After irrigations, the effluent samples were collected every day at the bottom of the soil columns and were analyzed. The results show that for all treatments, cations (e.g. Ca, Mg, Na and K) in the outflow decreased with time, exponentially. Manure treatment resulted in highest rate of Ca, Mg, Na leaching from soil solution, in spite of the control which had the lowest rate. In addition, pistachio residue had the most effect on K leaching. Manure treatment showed the most EC and SAR in the leachate, while gypsum application leads to the least rate of them. The findings of this research reveal different rates of cations leaching from soil profile, which is important in environmental issues. Keywords: Saline sodic soil, Reclamation, Organic Matter, Gypsum, Leachate.

Yazdanpanah, Najme; Mahmoodabadi, Majid

2010-05-01

259

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

260

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

261

Computer Simulation of Experiments: A Valuable Alternative to Traditional Laboratory Work for Secondary School Science Teaching.  

ERIC Educational Resources Information Center

Discusses the value of laboratory work, suggesting that it is not superior to other aids such as computer simulated experiments (CSE). Advantages of and problems related to use of CSE in the classroom, responses to criticisms of simulated laboratory work, and evaluation of CSE as a teaching aid are considered. (JN)

Moore, J. L.; Thomas, F. H.

1983-01-01

262

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

263

[Experience with a computer database in a cytogenetic laboratory].  

PubMed

The paper describes a computer system to support the data management in cytogenetics. Two major objectives are considered: the improvement of the quality and consistency of laboratory data and the support of data management in a large data set for research purposes. The entire system is divided into two logical parts. Firstly, a data collection module reads data from keyboard in an user-friendly way and checks for consistency including syntactic analysis of karyotype description. Secondly, the data are manipulated by a professional database system where three hierarchical data structures are introduced: 1. identification data, 2. investigation data and 3. karyotype description. Since 1984 we collected 1820 patients, 2800 investigations and 2760 karyotypes in the system. Currently, the system is reimplemented on IBM compatible machine using "dBase" database system in order to increase the operational speed and enhance the transportability of the system. PMID:2393879

Musilová, J; Hovorka, R; Zemanová, Z; Michalová, K; Svacina, S

1990-06-15

264

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

265

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

266

Conduction in Multiphase ParticulateFibrous Networks Simulations and Experiments on Li-ion Anodes  

E-print Network

promising Li-ion battery technologies incorporate nanoarchitectured carbon networks, typically in the form electronically February 7, 2003. Several promising Li-ion battery technologies incorporate nanoarchitecturedConduction in Multiphase ParticulateÃ?Fibrous Networks Simulations and Experiments on Li-ion Anodes

Sastry, Ann Marie

267

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

268

Evidence of compound-dependent hydrodynamic and mechanical transverse dispersion by multitracer laboratory experiments.  

PubMed

Mass transfer, mixing, and therefore reaction rates during transport of solutes in porous media strongly depend on dispersion and diffusion. In particular, transverse mixing is a significant mechanism controlling natural attenuation of contaminant plumes in groundwater. The aim of the present study is to gain a deeper understanding of vertical transverse dispersive mixing of reaction partners in saturated porous media. Multitracer laboratory experiments in a quasi two-dimensional tank filled with glass beads were conducted and transverse dispersion coefficients were determined from high-resolution vertical concentration profiles. We investigated the behavior of conservative tracers (i.e., fluorescein, dissolved oxygen, and bromide), with different aqueous diffusion coefficients, in a range of grain-related Peclet numbers between 1 and 562. The experimental results do not agree with the classical linear parametric model of hydrodynamic dispersion, in which the transverse component is approximated as the sum of pore diffusion and a compound-independent mechanical dispersion term. The outcome of the multitracer experiments clearly indicates a nonlinear relation between the dispersion coefficient and the average linear velocity. More importantly, we show that transverse mechanical dispersion depends on the diffusion coefficient of the compound, at least at the experimental bench-scale. This result has to be considered in reactive-transport models, because the typical assumption that two reactants with different aqueous diffusive properties are characterized by the same dispersive behavior does not hold anymore. PMID:20020677

Chiogna, Gabriele; Eberhardt, Christina; Grathwohl, Peter; Cirpka, Olaf A; Rolle, Massimo

2010-01-15

269

Laboratory evaporation experiments in undisturbed peat columns for determining peat soil hydraulic properties  

NASA Astrophysics Data System (ADS)

One of the key parameters controlling greenhouse gas (GHG) emissions from organic soils is water table depth. Thus, a detailed analysis of the hydrology is essential for an accurate spatial upscaling of the information of local GHG emission measurements to the regional and national scale. For the interpretation and numerical modeling of water table fluctuations, knowledge about soil hydraulic parameters is crucial. In contrast to mineral soils, the hydraulic properties of organic soils differ in several aspects. Due to the high amount of organic components, strong heterogeneity, and shrinkage and swelling of peat, accompanied by changing soil volume and bulk density, it is difficult to describe peat soil moisture dynamics with standard hydraulic functions developed for mineral soils. The objective of this study was to determine soil hydraulic properties for various undisturbed peat columns (diameter: 30 cm, height: 20 cm). Laboratory evaporation experiments were conducted for peat soils from five different test sites of the German joint research project "Organic Soils". Due to different land use histories, the peat samples covered a broad range of degradation states, which is known to strongly influence peat soil hydraulic properties. Pressure head, moisture content, weight loss and water level were monitored during the evaporation experiment. In numerical simulations using HYDRUS-1D the experimental data were used for an inverse-estimation of the soil hydraulic parameters using "shuffled complex evolution" and "covariance matrix adaption" optimization schemes. Besides the commonly applied van Genuchten-Mualem parameterization, several alternative soil parameterizations are evaluated.

Dettmann, Ullrich; Frahm, Enrico; Bechtold, Michel

2013-04-01

270

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...

271

Laser Plasma Acceleration Experiment at the Naval Research Laboratory.  

NASA Astrophysics Data System (ADS)

The traditional long term strategy for producing high quality electron beams in a single stage LWFA involves three elements: operation in the resonant or standard regime, the use of optical guiding to extend the acceleration region, and external injection of a precisely-phased, high quality injection electron bunch. The standard regime and optical guiding has been studied by many research groups and promise good results for the acceleration. The creation of the electron beam for external injection is still a very problematic issue. Most experiments to date have operated in the self modulated (SM) regime, which produces very large accelerating gradients but poor quality electron beams with large energy spread. More recently, quasi-monoenergetic acceleration of particles from the background plasma has been observed in simulations and experiments operating in a shorter pulse regime. Such quasi-monoenergetic electrons could be a candidate for injection into a following stage of standard LWFA if not for the relatively poor shot to shot reproducibility. We are in the initial stage of experiments to generate injection electrons using the HD-LIPA schemes with a 10 TW 50 fs laser system. The second stage accelerator will be a capillary discharge plasma channel for extended acceleration distance. Preliminary results, including statistics on the stability of quasi-monoenergetic acceleration, will be presented. Supported by DOE and ONR.

Kaganovich, D.; Ting, A.; Gordon, D.; Hubbard, R.; Jones, T.; Zigler, A.; Sprangle, P.

2006-10-01

272

Variability in mixing efficiency and laboratory analyses of a common diet mixed at 25 experiment stations.  

PubMed

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 fortified corn-soybean meal diet was mixed at each station using a common diet formula (except for vitamin and trace-mineral additions). The diet was calculated to contain 14% crude protein (CP), 0.65% Ca, 0.50% P, and 125 ppm Zn (based on 100 ppm added Zn). After mixing, samples were collected from the initial 5% of feed discharged from the mixer, after 25, 50, and 75% was discharged, and from the final 5% of discharged feed. The five samples were sent to the University of Kentucky, finely ground, and divided into subsamples. Each set of five subsamples from each station was distributed to three randomly selected stations for analysis of CP, Ca, P, and Zn (i.e., each station analyzed five diet sub-samples from three other stations). In addition, two commercial and two station laboratories analyzed composites of the five subsamples from each of the 25 mixed diets. Based on the laboratories that analyzed all diets, means were 13.5, 0.65, and 0.52%, and 115 ppm for CP, Ca, P, and Zn, respectively. Ranges of 11.8 to 14.6% CP, 0.52 to 0.85% Ca, 0.47 to 0.58% P, and 71 to 182 ppm of Zn were found among the 25 diet mixes. The coefficients of variation among the 25 diet samples for CP, Ca, P, and Zn were 4.3, 9.3, 4.1, and 17.4%, and among the 25 laboratories were 3.6, 12.5, 10.7, and 11.1%, respectively. Overall analyses of the five sub samples were, respectively, CP: 13.4, 13.6, 13.4, 13.5, and 13.4% (P < 0.06); Ca: 0.66, 0.67, 0.67, 0.66, and 0.67%; P: 0.50,0.51,0.51,0.50, and 0.50%; and Zn: 115, 116, 112, 113, and 120 ppm (P < 0.001). Diets were not uniformly mixed at all stations (station x sample No. was P < 0.08 for Ca and P < 0.01 for CP, P, and Zn). Among stations, the range of the five samples, expressed as a percentage of the mean and averaged for CP, Ca, P, and Zn, varied from +/- 1.1% (i.e., 98.9 to 101.0%) to +/- 12.9% (84.6 to 110.4%), with an overall average of +/- 5.2%. Neither type nor volume of mixers was related to mixing uniformity. The results suggest that uniformity of diet mixes varies among experiment stations, that some stations miss their targeted levels of nutrients (especially Zn), and that the variability among experiment station laboratories in analysis of dietary Ca, P, and Zn in mixed diets is quite large. PMID:12643493

Cromwell, G L; Brendemuhl, J H; Chiba, L I; Cline, T R; Crenshaw, T D; Dove, C R; Easter, R A; Ewan, R C; Ferrell, K C; Hamilton, C R; Hill, G M; Hitchcock, J D; Knabe, D A; Kornegay, E T; Lewis, A J; Libal, G W; Lindemann, M D; Mahan, D C; Maxwell, C V; McConnell, J C; Nelssen, J L; Pettigrew, J E; Southern, L L; Veum, T L; Yen, J T

2003-02-01

273

Onset of perched water in a gradually layered soil: a laboratory experiment  

NASA Astrophysics Data System (ADS)

The genetic layering of the soil hydrological properties can significanly affect a number of processes as the onset of soil-slips, the runoff production and those related to the interaction between soil, water, plants and atmosphere. Therefore, with the aim of better understanding some aspects of these processes, we focused on the effect, during an imbibition process, of the decrease of the soil hydraulic conductivity at saturation Ks. A laboratory experiment was setup in order to observe the conditions and dynamics of the onset of a perched water in a gradually layered soil. A prismatic column was realised and filled with 9 different soil strata, each 0.1 m deep, whose grain-size distribution curve and porosity were such as to reproduce an exponential decay of Ks, on the basis of the application of a modified Kozeny-Carman relatioship. The so-rebuilt soil was artificially wetted by means of a rainfall simulator at a rate previously determined in order to maintain a constant water content on the surface for 9 hours. Istantaneous volumetric water content profiles were measured along the soil profile by means of 9 TDR probes and a multiplexer device. As a result of the experiment we observed and documented the formation of a water content peak at about 0.15 m depth, about 1.5 h after the beginning of the imbibition process. Then the peak emphasised and moved downward and a perched water formed at an intermediate height in the column, about 6 h after the beginning of the experiment. By this experiment we could then verify the formation of a water content peak, as predicted by a previously developed theoretical model and by a finite volume numerical simulation. The peak is then enveloped reaching the saturation as the wetting front moves downward. The perched water depth then rapidly increased upward while the wetting front slowly travelled downward. Before the transition toward saturation, the experiment supported the phoenomenological aspects enlightened by the analytical solution, although the adopted Gardner's constitutive laws tend to overestimate the unsaturated conductivity for most of the soils. A quantitative good agreement was observed between the experimental data and the numerical simulations.

Barontini, S.; Belluardo, G.; Bacchi, B.; Ranzi, R.

2009-04-01

274

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

275

How astronauts would conduct a seismic experiment on the planet Mars  

NASA Astrophysics Data System (ADS)

During the Summer 2001 Flashline Mars Arctic Research Station (M.A.R.S.) campaign in Devon Island, Nunavut, Canada, the crew of the second rotation conducted a geophysics experiment aiming at assessing the feasibility of an active seismology method to detect subsurface water on Mars. A crew of three deployed a line of 24 sensors. Reflected and refracted signals produced by mini-quakes generated by a sledge hammer were recorded by a seismograph. The experiment was conducted three times, once in a dry run and twice during simulated Extra-Vehicular Activities (EVA) on the edge of the Haughton crater, allowing a three dimensional characterization of the subsurface ground to a depth of several hundred meters. Data were recorded for later detailed processing. A third EVA attempt inside the crater had to be aborted because of the poor weather and terrain conditions. Despite this failed attempt, a large amount of results were collected. Several operational lessons were learned from conducting this experiment under simulated EVA conditions. This paper presents the experiment and the methodology used, reviews the experiment performance and summarizes the results obtained and the operational lessons learned.

Pletser, V.; Lognonne, P.; Dehant, V.

276

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

277

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

278

Laboratory experience with a radiometric method for detecting bacteremia.  

PubMed Central

Two bacteriologic systems for detecting bacteria in blood were compared; the automated radiometric BACTEC and the conventional method used in our laboratory for many years. BACTEC consisted of two bottles with 30 ml and the conventional method with 50 ml of media for aerobes and anaerobes. The BACTEC bottles were inoculated with 2 to 3 ml and the conventional with 4 to 5 ml of blood at the patient's bedside. Out of the 3,045 blood specimens cultured (804 patients), 262 (117 patients) were positive by one or both methods. The conventional system detected 5more cultures. The explanation of the differences is discussed. Positive blood cultures were detected by the BACTEC procedure as early as 6 h after the blood collection. In the first 24 h, on the average, 77% of aerobic organisms were detected by the BACTEC as compared to 48% by the conventional system. All anaerobic BACTEC cultures were positive within 4 days, whereas the conventional system detected at that time 74%. At day 4, 67% of fungi were detected by the BACTEC and only 27% by the conventional system. Of the 3,045 blood cultures examined by the BACTEC, 208 were recorded as false positive with growth index readings ranging from 30 to 59. PMID:1100660

Thiemke, W A; Wicher, K

1975-01-01

279

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

280

Effect of ionic ordering in conductivity experiments of DNA aqueous solutions  

E-print Network

The effects of ionic ordering in DNA water solutions are studied by conductivity experiments. The conductivity measurements are performed for the solutions of DNA with KCl salt in the temperature range from 28 to 70 C. Salt concentration vary from 0 to 2 M. The conductivity of solutions without DNA but with the same concentration of KCl salt are also performed. The results show that in case of salt free solution of DNA the melting process of the double helix is observed, while in case of DNA solution with added salt the macromolecule denaturation is not featured. For salt concentrations lower than some critical one (0.4 M) the conductivity of DNA solution is higher than the conductivity of KCl water solution without DNA. Starting from the critical concentration the conductivity of KCl solution is higher than the conductivity of DNA solution with added salt. For description of the experimental data phenomenological model is elaborated basing on electrolyte theory. In framework of the developed model a mechanis...

Liubysh, O O; Tkachov, S Yu; Perepelytsya, S M

2014-01-01

281

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

282

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

283

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

284

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

285

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

286

Enhancing the Student Experience of Laboratory Practicals through Digital Video Guides  

ERIC Educational Resources Information Center

Laboratory-based learning allows students to experience bioscience principles first hand. In our experience, practical content and equipment may have changed over time, but teaching methods largely remain the same, typically involving; whole class introduction with a demonstration, students emulating the demonstration in small groups, gathering…

Croker, Karen; Andersson, Holger; Lush, David; Prince, Rob; Gomez, Stephen

2010-01-01

287

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

288

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

289

Preparing a Laboratory-Based Thesis: Chinese International Research Students' Experiences of Supervision  

ERIC Educational Resources Information Center

This qualitative study examined Chinese international laboratory-based research students' experiences of supervision during the first six to eighteen months of their candidature in Singapore. The experiences of marginalization in student/supervisory relationship identified in the study, particularly in the first six months, may very largely be…

McClure, Joanne W.

2005-01-01

290

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

291

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

292

A Nationwide Laboratory Examining Trust and Trustworthiness by Integrating Behavioural Experiments into Representative Surveys  

Microsoft Academic Search

Typically, laboratory experiments suffer from homogeneous subject pools and self-selection biases. The usefulness of survey data is limited by measurement error and by the questionability of their behavioural relevance. Here we present a method integrating interactive experiments and representative surveys thereby overcoming crucial weaknesses of both approaches. One of the major advantages of our approach is that it allows for

Ernst Fehr; Urs Fischbacher; Bernhard von Rosenbladt; Gert Georg Wagner

2003-01-01

293

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

294

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

ERIC Educational Resources Information Center

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

Ewing, Galen W., Ed.

1978-01-01

295

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

296

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

297

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

298

Oil Formation: An "Unexpected" Difficulty in an Elementary Organic Laboratory Experiment  

ERIC Educational Resources Information Center

Describes an undergraduate organic laboratory experiment involving the separation of an unknown solid organic acid and an unknown solid organic base. The experiment is designed to present the student with an unexpected difficulty, namely, the formation of a separable viscous liquid, to see how the student handles this difficulty. (MLH)

Lewis, Dennis A.

1975-01-01

299

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...

300

Designing and Conducting a Purification Scheme as an Organic Chemistry Laboratory Practical  

ERIC Educational Resources Information Center

An open-ended laboratory practical has been developed that challenges students to evaluate when different purification techniques are appropriate. In contrast to most lab practicals, the overall grade includes an evaluation of spectral analysis as well as writing skills. However, a significant portion of the grade lies in successful execution of a…

Graham, Kate J.; Johnson, Brian J.; Jones, T. Nicholas; McIntee, Edward J.; Schaller, Chris P.

2008-01-01

301

Effluent Monitoring Procedures: Basic Laboratory Skills. Staff Guide for Conducting the Course.  

ERIC Educational Resources Information Center

This manual is designed for use by instructors who will have to teach others the basic laboratory skills needed to perform National Pollution Discharge Elimination System (NPDES) Analyses. It includes topics related to the presentation of training courses in which the NPDES analyses would be taught. These topics include: examples of course…

Engel, William T.; And Others

302

Laboratory studies of the electrical conductivity of silicate perovskites at high pressures and temperatures  

NASA Technical Reports Server (NTRS)

The electrical conductivities of two silicate perovskites and a perovskite-magnesiowuestite assemblage, all having an atomic ratio of Mg to Fe equal to 0.88/0.12, have been measured with alternating current and direct current (dc) techniques at simultaneously high pressures and temperatures. Measurements up to pressures of 80 GPa and temperatures of 3500 K, using a laser-heated diamond anvil cell, demonstrate that the electrical conductivity of these materials remains below 10-3 S/m at lower mantle conditions. The activation energies for electrical conduction are between 0.1 and 0.4 eV from the data, and the conduction in these perovskites is ascribed to an extrinsic electronic process. The new measurements are in agreement with a bound that was previously obtained from dc measurements for the high-PT conductivity of perovskite-dominated assemblages. The results show that the electrical conductivity of (Mg/0.88/Fe/0.12)SiO3 perovskite differs significantly from that of the earth's deep mantle, as inferred from geophysical observations.

Li, Xiaoyuan; Jeanloz, Raymond

1990-01-01

303

Heat Flow Experiment Results from IODP Expedition 317 at Canterbury Basin, New Zealand: Insight on Thermal Conductivity Variation with Lithification  

NASA Astrophysics Data System (ADS)

Thermal conductivity is an essential parameter, together with geothermal gradient, for estimating the heat flow. An important factor controlling thermal conductivity is porosity. Many studies have looked at the relationship between thermal conductivity and porosity in the laboratory setting, however, a natural dataset that can be compared with the experimental results is rare. IODP 317 conducted deep drilling into Canterbury basin in November 2010-January 2011. Three sites on the inner shelf (Sites U1351, 1353-1354) and one site on the continental slope (Site U1352) were drilled where the maximum bottom-hole depth of 1927 mbsf was reached at Site U1352. During on-board experiment, the thermal conductivity was measured on the recovered cores at an interval 0.5-1 m together with moisture and bulk density. In general, the thermal conductivity values increase with depth and correlate positively and negatively with bulk density and porosity, respectively. Detailed examination at Site U1352, however, shows an abrupt change in thermal conductivity and porosity with depth occurs at approximately 600-800 mbsf, coinciding with the depth where lithological transition takes place from marl to limestone. The variation of porosity with depth can be described as two linear relationships with respect to this transition depth: Porosity (%) = - 0.006462 * Depth (m) + 47.27 for unconsolidated sediments (< 600-800 mbsf), and Porosity (%) = - 0.01032 * Depth (m) + 31.97 for rocks (> 600-800 mbsf). Correspondingly, the matrix-thermal conductivity is estimated as 2.51 and 3.27 W/m/K for unlithified and lithified sections using a simple water-matrix two-component model. To examine if our thermal conductivity-porosity relationship holds for other marine environments, we compare the results of IODP 317 with those obtained at other deep drilling sites. The study will shed a new insight into the evolution of continental margins and also help us to better assess the potential of hydrocarbons and risk of slope failures.

Kim, Y.; Lee, S.

2011-12-01

304

Tailored blast wave formation: Developing experiments pertinent to laboratory astrophysics  

SciTech Connect

The first production of 'tailored' blast waves in a cluster media using an intense, 2x10{sup 16} W cm{sup -2}, laser pulse is reported. This new technique produces cylindrical blast waves with a strong axial modulation of variable spatial frequency as a seed for instability growth. Spherical or cylindrical colliding blast waves can also be produced. Energy deposition in the cluster medium was modified using moderate-power (<10{sup 15} W cm{sup -2}) 'laser-machining', which destroyed clusters in selected regions while keeping the atomic density constant. Electron density profiles track the time evolution showing the production of strongly modulated blast waves and the development of a thin shell after {approx_equal}6 ns in H{sub 2}. Similarity parameters suggest that the hydrogen results are hydrodynamically scalable, but instabilities are precluded by the lack of radiation and low Reynolds number. Similar argon and xenon experiments do not form blast waves on the studied time scale, but indicate that radiation might become influential later in the evolution.

Moore, Alastair S.; Symes, Daniel R.; Smith, Roland A. [Blackett Laboratory, Imperial College of Science, Technology and Medicine, London SW7 2BZ (United Kingdom)

2005-05-15

305

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

306

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

307

Spectral probing of impact-generated vapor in laboratory experiments  

NASA Astrophysics Data System (ADS)

High-speed spectra of hypervelocity impacts at the NASA Ames Vertical Gun Range (AVGR) captured the rapidly evolving conditions of impact-generated vapor as a function of impact angle, viewpoint, and time (within the first 50 ?s). Impact speeds possible at the AVGR (<7 km/s) are insufficient to induce significant vaporization in silicates, other than the high-temperature (but low-mass) jetting component created at first contact. Consequently, this study used powdered dolomite as a proxy for surveying the evolution and distribution of chemical constituents within much longer lasting vapor. Seven separate telescopes focused on different portions of the impact vapor plume and were connected through quartz fibers to two 0.35 cm monochromaters. Quarter-space experiments reduced the thermal background and opaque phases due to condensing particles and heated projectile fragments while different exposure times isolated components passing through different the fields of view, both above and below the surface within the growing transient cavity. At early times (<5 ?s), atomic emission lines dominate the spectra. At later times, molecular emission lines dominate the composition of the vapor plume along a given direction. Layered targets and target mixtures isolated the source and reveal that much of the vaporization comes from the uppermost surface. Collisions by projectile fragments downrange also make significant contributions for impacts below 60° (from the horizontal). Further, impacts into mixtures of silicates with powdered dolomite reveal that frictional heating must play a role in vapor production. Such results have implications for processes controlling vaporization on planetary surfaces including volatile release, atmospheric evolution (formation and erosion), vapor generated by the Deep Impact collision, and the possible consequences of the Chicxulub impact.

Schultz, Peter H.; Eberhardy, Clara A.

2015-03-01

308

Video of Miscible Fluid Experiment Conducted on NASA Low Gravity Airplane  

NASA Technical Reports Server (NTRS)

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

2003-01-01

309

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

310

Preservation of viable biological samples for experiments in space laboratories.  

PubMed

Standard viable preservation methods for biological samples using low temperatures have been investigated concerning their storage capabilities under higher temperature levels than usual. For a representative set of organism classes (plants, mammalian cells, arthropods and aquatic invertebrates), the minimum appropriate storage conditions have been identified by screening storage temperatures at -196 degrees, -80 degrees, -20 degrees, +4 degrees, +20 degrees/25 degrees C for periods from 2 days to 4 weeks. For storage below 0 degree C, as a typical cryopreservative, dimethylsulfoxide (DMSO) was used. For some samples, the addition of trehalose (as cryopreservative) and the use of a nitrogen atmosphere were investigated. After storage, the material was tested for vitality. The findings demonstrated that acceptable preservation can be achieved under higher storage temperatures than are typically applied. Small, dense cultured plant cells survive for 21 d when moderately cooled (+4 degrees to -20 degrees C); addition of trehalose enhances viability at -20 degrees C. For mammalian cells, the results show that human lymphocytes can be preserved for 3 d at 25 degrees C, 7 d at 4 degrees C and 28 d at -80 degrees C. Friend leukaemia virus transformed cells can be stored for 3 d at 25 degrees C, 14 d at 4 degrees C and 28 d at -80 degrees C. Hybridoma cells can be kept 7 d at 4 degrees C and 28 d at -20 degrees C or -80 degrees C. Model arthropod systems are well preserved for 2 weeks if maintained at lower temperatures that vary depending on the species and/or stage of development; e.g., 12 degrees C for Drosophila imagoes and 4-6 degrees C for Artemia nauplii. For aquatic invertebrates such as sea urchins, embryonic and larval stages can be preserved for several weeks at +6 degrees C, whereas sperm and eggs can best be stored at + 4 degrees C for up to 5 d at maximum. These results enhance the range of feasible space experiments with biological systems. Moreover, for typical terrestrial preservation methods, considerable modification potential is identified. PMID:8987576

Anthony, P; Ausseil, J; Bechler, B; Benguría, A; Blackhall, N; Briarty, L G; Cogoli, A; Davey, M R; Garesse, R; Hager, R; Loddenkemper, R; Marchant, R; Marco, R; Marthy, H J; Perry, M; Power, J B; Schiller, P; Ugalde, C; Volkmann, D; Wardrop, J

1996-06-27

311

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

312

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

313

Imaging the Central Conducting Lymphatics: Initial Experience with Dynamic MR Lymphangiography.  

PubMed

Purpose To describe a dynamic magnetic resonance (MR) lymphangiography technique after intranodal injection of gadolinium-based contrast agent and to assess its feasibility for evaluation of the central conducting lymphatics ( CCL central conducting lymphatics ) in patients with pathologic disorders that involve the CCL central conducting lymphatics . Materials and Methods A retrospective evaluation of experience with the dynamic MR lymphangiographic technique in six consecutive patients was performed after institutional review board approval. Written informed consent for the percutaneous procedure was obtained from the patient, parent, or the legally responsible guardian. The dynamic MR lymphangiographic technique involves ultrasonographically guided intranodal injection of gadolinium-based contrast material into the inguinal lymph nodes, combined with sequential imaging of the chest and abdomen with a three-dimensional sequence optimized for soft tissue with high spatial resolution that provides time-resolved imaging of lymphatic transit through the CCL central conducting lymphatics . Qualitative assessment of the images was performed for reliability of CCL central conducting lymphatics visualization and for associated findings that could explain the clinical symptoms, including lymphangiectasia, chylolymphatic reflux, and chylous leak. Results The procedure was technically successful in all six patients. The dynamic MR lymphangiographic findings confirmed the presence of normal CCL central conducting lymphatics morphologic structure in two patients and provided a possible explanation for clinical manifestations in the remaining four patients. The dynamic MR lymphangiographic procedure led to a change in management in two patients, continuation of conservative treatment in three patients, and confirmation of an alternative nonlymphatic diagnosis in one patient. Image quality for visualization of the CCL central conducting lymphatics was considered good in all cases by the two readers. There were no known adverse effects related to the procedure. Conclusion The dynamic MR lymphangiographic technique with intranodal injection of gadolinium-based contrast material is feasible and can provide useful information in a variety of lymphatic flow abnormalities involving the CCL central conducting lymphatics . © RSNA, 2014 Online supplemental material is available for this article. PMID:25325323

Krishnamurthy, Rajesh; Hernandez, Alberto; Kavuk, Serife; Annam, Aparna; Pimpalwar, Sheena

2014-10-15

314

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

NASA Astrophysics Data System (ADS)

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

Wang, A.; Freeman, J. J.

2009-12-01

315

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

316

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

317

Laboratory evaluation of Li isotopic fractionation in carbonates: inorganic precipitation experiments  

NASA Astrophysics Data System (ADS)

Laboratory experiments were conducted to precipitate calcite and aragonite micro-crystals separately under controlled temperature and growth-rate conditions. High purity aragonite and calcite were precipitated and were examined by XRD, Raman and SEM. It is evident that high precipitation rate and low temperature in favor of mixed-carbonates formation. The obtained carbonate precipitates, along with paired fluids and the mother solutions, were acid dissolved and analyzed for various trace elements and stable isotopes using high resolution ICPMS and multi-collector ICP-MS, respectively. The Li partition coefficient (DLi) and the Li isotopic fractionation factors ("ÑLi) were calculated at temperature between 5 and 40°C, where other stable isotopes (i.e., Li, B, Ca, and Sr) were also determined. The derived DLi varies slightly (1.3- 1.6E-3) in aragonite, in strong contrast to that of large variation in calcite, DLi =2.1-9.2E-2. The calculated "ÑLi at various temperatures keep rather constant and show a small positive gradient (0.03 permil/°C) in aragonite. These results agree with previous calcite precipitation and were applied to study ?7Li in coralline skeleton.

You, C.; Wang, W.; Lin, B.; Wang, B.; Huang, K.; Lin, P.

2008-12-01

318

Dynamics of Soil Water Evaporation during Soil Drying: Laboratory Experiment and Numerical Analysis  

PubMed Central

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

Han, Jiangbo; Zhou, Zhifang

2013-01-01

319

Random focusing of nonlinear acoustic N-waves in fully developed turbulence: laboratory scale experiment.  

PubMed

A laboratory experiment was conducted to study the propagation of short duration (25 ?s) and high amplitude (1000 Pa) acoustic N-waves in turbulent flow. Turbulent flows with a root-mean-square value of the fluctuating velocity up to 4 m/s were generated using a bidimensional nozzle (140 × 1600 mm(2)). Energy spectra of velocity fluctuations were measured and found in good agreement with the modified von Ka?rma?n spectrum for fully developed turbulence. Spherical N-waves were generated by an electric spark source. Distorted waves were measured by four 3 mm diameter microphones placed beyond the turbulent jet. The presence of turbulence resulted in random focusing of the pulse; more than a threefold increase of peak pressures was occasionally observed. Statistics of the acoustic field parameters were evaluated as functions of the propagation distance and the level of turbulence fluctuations. It is shown that random inhomogeneities decrease the mean peak positive pressure up to 30% at 2 m from the source, double the mean rise time, and cause the arrival time about 0.3% earlier than that for corresponding conditions in still air. Probability distributions of the pressure amplitude possess autosimilarity properties with respect to the level of turbulence fluctuations. PMID:22225017

Averiyanov, Mikhail; Ollivier, Sébastien; Khokhlova, Vera; Blanc-Benon, Philippe

2011-12-01

320

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

321

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

322

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

NASA Astrophysics Data System (ADS)

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

Silverman, Mark P.; Silverman, Christopher R.

2000-02-01

323

Impacts of Climatic Change On Peatland Hydrochemistry; A Laboratory-Based Experiment  

Microsoft Academic Search

A laboratory simulation of a reduction in water table height that could be anticipated from current climate change models, resulted in a change in the efficiency with which a valley-bottom wetland acted as a sink\\/source of nutrients. Effects were confined to the upper 10 cm of the profile, but since this depth has the greatest hydraulic conductivity, it was noted

C. Freeman; M. A. Lock; B. Reynolds

1993-01-01

324

Case-Study Investigation of Equine Maternity via PCR-RFLP: A Biochemistry Laboratory Experiment  

PubMed Central

A simple and robust biochemistry laboratory experiment is described that uses restriction fragment length polymorphism (RFLP) of polymerase chain reaction (PCR) products to verify the identity of a potentially valuable horse. During the first laboratory period, students purify DNA from equine samples and amplify two loci of mitochondrial DNA. During the second laboratory period, students digest PCR products with restriction enzymes and analyze the fragment sizes through agarose gel electrophoresis. An optional step of validating DNA extracts through realtime PCR can expand the experiment to three weeks. This experiment, which has an engaging and versatile scenario, provides students with exposure to key principles and techniques of molecular biology, bioinformatics, and evolution in a forensic context. PMID:24363455

Millard, Julie T.; Chuang, Edward; Lucas, James S.; Nagy, Erzsebet E.; Davis, Griffin T.

2013-01-01

325

Case-Study Investigation of Equine Maternity via PCR-RFLP: A Biochemistry Laboratory Experiment.  

PubMed

A simple and robust biochemistry laboratory experiment is described that uses restriction fragment length polymorphism (RFLP) of polymerase chain reaction (PCR) products to verify the identity of a potentially valuable horse. During the first laboratory period, students purify DNA from equine samples and amplify two loci of mitochondrial DNA. During the second laboratory period, students digest PCR products with restriction enzymes and analyze the fragment sizes through agarose gel electrophoresis. An optional step of validating DNA extracts through realtime PCR can expand the experiment to three weeks. This experiment, which has an engaging and versatile scenario, provides students with exposure to key principles and techniques of molecular biology, bioinformatics, and evolution in a forensic context. PMID:24363455

Millard, Julie T; Chuang, Edward; Lucas, James S; Nagy, Erzsebet E; Davis, Griffin T

2013-11-12

326

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

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

327

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

328

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

PubMed Central

Background Research on root cause analysis (RCA), a pivotal component of many patient safety improvement programmes, is limited. Objective To study a cohort of health professionals who conducted RCAs after completing the NSW Safety Improvement Program (SIP). Hypothesis Participants in RCAs would: (1) differ in demographic profile from non?participants, (2) encounter problems conducting RCAs as a result of insufficient system support, (3) encounter more problems if they had conducted fewer RCAs and (4) have positive attitudes regarding RCA and safety. Design, setting and participants Anonymous questionnaire survey of 252 health professionals, drawn from a larger sample, who attended 2?day SIP courses across New South Wales, Australia. Outcome measures Demographic variables, experiences conducting RCAs, attitudes and safety skills acquired. Results No demographic variables differentiated RCA participants from non?participants. The difficulties experienced while conducting RCAs were lack of time (75.0%), resources (45.0%) and feedback (38.3%), and difficulties with colleagues (44.5%), RCA teams (34.2%), other professions (26.9%) and management (16.7%). Respondents reported benefits from RCAs, including improved patient safety (87.9%) and communication about patient care (79.8%). SIP courses had given participants skills to conduct RCAs (92.8%) and improve their safety practices (79.6%). Benefits from the SIP were thought to justify the investment by New South Wales Health (74.6%) and committing staff resources (72.6%). Most (84.8%) of the participants wanted additional RCA training. Conclusions RCA participants reported improved skills and commitment to safety, but greater support from the workplace and health system are necessary to maintain momentum. PMID:17142585

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

2006-01-01

329

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

330

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

331

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

332

What did we learn on Titan's aerosols composition from ACP experiment and laboratory experiments?  

NASA Astrophysics Data System (ADS)

Taking into account the constraints retrieved from ACP experiment observations, we will review what we learn from Titan's aerosol analogues studies to understand the potential composition of Titan's aerosols.

Coll, Patrice; Acp Team

2010-04-01

333

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

334

STS-47 MS / PLC Lee conducts SLJ experiment M20 using the image furnace  

NASA Technical Reports Server (NTRS)

STS-47 Mission Specialist (MS) and Payload Commander (PLC) Mark C. Lee, wearing rubber gloves, prepares to load raw material (or crystal seed material) into the upper shaft (or lower shaft) of the Image Furnace. Lee is conducting Spacelab Japan (SLJ) experiment M20, Growth of Samarskite Crystal in Microgravity, during which a single crystal will be produced using the traveling solvent float zone method. The Image Furnace is located in SLJ NASDA Material Sciences Rack 8. SLJ science module is in the payload bay (PLB) of the Earth-orbiting Endeavour, Orbiter Vehicle (OV) 105.

1992-01-01

335

Laboratory-scale experiments applied to the design of a two-stage submerged combustion evaporation system.  

PubMed

To simulate a submerged combustion evaporation (SCE) process under laboratory conditions, this study conducted three kinds of indirect-heating evaporation experiments, including normal evaporation, vacuum evaporation, and gas-carrying evaporation experiments on mature municipal solid waste (MSW) landfill leachate. The results showed that the organic concentrations in terms of COD in condensates were always very high at the beginning, then decreased rapidly, and stabilized at a low level, which suggests that only the forepart of vapors need to be safely treated to control the discharge of organic pollutants. This study applied the process in developing a two-stage SCE system, which has been implemented for the treatment of biologically pretreated and concentrated leachate from Membrane Bioreactor (MBR) and Reverse Osmosis (RO) combined process in the Beishenshu MSW Landfill, Beijing, China. The result shows that the two-stage SCE system can successfully further concentrate refractory organic matter in concentrated leachate and remove volatile organics from the vapor. PMID:16781137

Yue, Dongbei; Xu, Yudong; Mahar, Rasool Bux; Liu, Fuqiang; Nie, Yongfeng

2007-01-01

336

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

337

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

338

Correction of an image distorted by a wavy water surface: laboratory experiment.  

PubMed

A laboratory-modeling installation for experimental investigations of light and image transfer through a wavy water surface was described. Measurements of the modulation transfer function of turbid media and a wavy surface have proved the reliability of laboratory image transfer modeling. An experiment to correct the image distortion caused by surface wave refraction of an underwater object was done using laboratory-modeling installation. A color digital camera was used to simultaneously obtain an image of the object and a glitter pattern on the surface. Processing the glitter pattern allows one to obtain the values of surface slopes at a limited number of points and to use these slopes for retrieval of image fragments. A totally corrected image is formed by accumulating the fragments. The accumulated image closely matches an original undistorted image. The experiment demonstrates that correction of image distortion produced by surface waves is possible, at least in special cases. PMID:19079476

Levin, Iosif M; Savchenko, Victor V; Ju Osadchy, Vladimir

2008-12-10

339

Crop yield and light / energy efficiency in a closed ecological system: two laboratory biosphere experiments  

NASA Astrophysics Data System (ADS)

Two crop growth experiments in the soil-based closed ecological facity, Laboratory Biosphere, were conducted from 2003-2004 with candidate space life support crops. Apogee wheat (Utah State University variety) was grown, planted in 2 densities, 400 and 800 seeds m-2. The lighting regime for the wheat crop was 16 hours of light -- 8 hours dark at a total light intensity of around 840 mol m2 sec-1 and 48.4 mol m-2 d-1 over 84 days Average biomass was 1395 g m-2, 16.0 g m-2 day-1 and average seed production was 689 g m-2 and 7.9 g m2 day-1. The less densely planted side was more productive than the denser planting, with 1634 g m-2 and 18.8g m-2 day-1 of biomass vs. 1156 g m-2 and 13.3 g m-2 day-1; and a seed harvest of 812.3 g m-2 and 9.3 g m-2 day-1 vs. 566.5 g m-2 and 6.5 g m-2 day-1 Harvest index was 0.49 for the wheat crop. The experiment with sweet potato used TU-82-155, a compact variety developed at Tuskegee University. Light during the sweet potato experiment, on a 16 hour on/8 hours dark cycle, totalled 5568 total moles of light in 126 days for the sweet potatoes, or an average of 44.2 moles m-2 day-1. Temperature regime was 28 deg +/- 3 deg C day /22 deg +/- 4 deg C night. Sweet potato tuber yield was 39.7 kg wet weight, or an average of 7.4 kg m-2 and 7.7 kg dry weight of tubers since dry weight was about 18.6% wet weight.^Average per day production was 58.7 g m-2 day-1 wet weight and 11.3 g m-2 day-1. For the wheat, average light efficiency was 0.34 grams biomass per mole, and 0.17 grams seed per mole. The best area of wheat had an efficiency of light utilization of 0.51 g biomass per mole and 0.22 g seed per mole. For the sweet potato crop, light efficiency per tuber wet weight was 7.13 g/mole and 1.38 g dry weight of tuber per mole of light. The best area of tuber production had 9.49 g/mole wet weight and 1.85 g/mole of light dry weight. Production from the wheat was The Laboratory Biosphere experiment's light efficiency was somewhat higher than the USU field results but somewhat below greenhouse trials at comparable light levels, and the best portion of the crop at 0.22g/mole was inbetween those values. Sweet potato production was overall close to 50% higher than trials using hydroponic methods with TU-82-155 at NASA JSC. Compared to projected yields for the Mars on Earth life support system, these wheat yields were about 15% higher, and the sweet potato yields averaged over 80% higher

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

340

A Static Method as an Alternative to Gel Chromatography: An Experiment for the Undergraduate Biochemistry Laboratory  

ERIC Educational Resources Information Center

This article describes a static method as an alternative to gel chromatography, which may be used as an undergraduate laboratory experiment. In this method, a constant mass of Sephadex gel is swollen in a series of protein solutions. UV-vis spectrophotometry is used to find a partition coefficient, KD, that indicates the fraction of the interior…

Burum, Alex D.; Splittgerber, Allan G.

2008-01-01

341

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

342

eMerge: An European Educational Network for Dissemination of online Laboratory Experiments  

Microsoft Academic Search

This paper presents the development of the eMerge project, an innovative and advanced educational network structure that will permit the dissemination of online laboratory experiments to support engineering and science education. This project has been performing in the framework of European Community SOCRATES - MINERVA program. Partners from nine different educational institutions are involved in this project. The actual work

Ruben Cabello; Francisco Gomez-Arribas; Javier Martinez; Hans Effinger; Fachbereich Elektrotechnik; Germany Reinhold; S. Jaeger; Tor A. Fjeldly; Kjell Jeppson

343

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

344

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

345

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

346

RELAB (REFLECTANCE EXPERIMENT LABORATORY): A NASA MULTIUSER SPECTROSCOPY FACILITY. Carl M. Pieters  

E-print Network

to near-infrared wavelengths, and 2) a Nicolet 870 Nexus FTIR spectrometer for a) near- to far- infrared- to far-infrared measure- ments. Components of the system are shown in Figure 3. Much of this systemRELAB (REFLECTANCE EXPERIMENT LABORATORY): A NASA MULTIUSER SPECTROSCOPY FACILITY. Carlé M. Pieters

Hiroi, Takahiro

347

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

348

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

349

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

350

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

351

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

352

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

353

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

354

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. 21 refs., 7 figs., 3 tabs.

Heath, M.T.; Geist, G.A.; Drake, J.B.

1990-09-01

355

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

356

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

357

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

358

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

359

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

360

Rotating shallow water flow past an obstacle : numerical and laboratory experiments  

E-print Network

and the ver- tical stratification. We use the rotating shallow-water model as the simplest model to account.1 Theoretical model Figure 2. Shallow water model We use the shallow water equations in a rotating frame whichRotating shallow water flow past an obstacle : numerical and laboratory experiments Ga¨ele Perret

�cole Normale Supérieure

361

A Laboratory Experience in Fitness Assessment and Exercise Prescription Using a Personal Microcomputer.  

ERIC Educational Resources Information Center

Describes a laboratory experience for a general biology or physiology course designed to increase awareness and promote principles of exercise prescription. The fitness evaluation methods utilized, use of the microcomputer to manipulate data from diagnostic tests, development of individualized exercise prescriptions by each student, and…

Francis, Kennon

1984-01-01

362

Ion acoustic wave experiments in a high school plasma physics laboratory Walter Gekelman  

E-print Network

Ion acoustic wave experiments in a high school plasma physics laboratory Walter Gekelman Department of California, Los Angeles, California 90095 R. Baker University High School, Los Angeles, California 90025 W University High School, Los Angeles, California 90025 T. Kim Palos Verdes Peninsula High, Palos Verdes

California at Los Angles, University of

363

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

364

Laboratory Experiments for Code Validation of Multiutility Spacecraft Charging Analysis Tool (MUSCAT)  

Microsoft Academic Search

The multiutility spacecraft charging analysis tool (MUSCAT), a spacecraft charging analysis software, has been developed as a collaboration work between Japan Aerospace Exploration Agency and Kyushu Institute of Technology. Laboratory experiments for fundamental code validation were carried out in both facilities' plasma chambers. MUSCAT is a particle simulation code based on particle-in-cell (PIC) and particle tracking (PT) algorithms capable of

Satoshi Hosoda; Takanobu Muranaka; Hitoshi Kuninaka; Jeongho Kim; Shinji Hatta; Naomi Kurahara; Mengu Cho; Hiroko O. Ueda; Kiyokazu Koga; Tateo Goka

2008-01-01

365

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

366

Simulation of the Sandia Laboratory Salt Block II, brine migration experiment  

SciTech Connect

The finite-element code SPECTROM-58 is used to simulate the Salt Block II brine migration experiment. All input quantities for the computer code are treated as stochastic quantities. The measured results of the Salt Block II experiment are within the range of the SPECTROM-58 computed results. However, the range of calculated results that arises from the uncertainty in the input quantities is so large that an evaluation of the aptness of SPECTROM-58 is precluded. The current uncertainty in several of the input parameters must be reduced through laboratory testing before the Salt Block II experiment can be used for validating SPECTROM-58. 29 refs., 22 figs., 11 tabs.

Ratigan, J.L.; Brandshaug, T.

1988-03-01

367

Cell lines used for microbeam and track segment studies at RARAF Experiments conducted at RARAF have used a host of adherent cell lines for various experiments. While  

E-print Network

Cell lines used for microbeam and track segment studies at RARAF Experiments conducted at RARAF have used a host of adherent cell lines for various experiments. While the primary method of attachment to discuss their favorite cell line. Listed below are cells used for experiments at RARAF. Selected

368

Identifying a Protein by MALDI TOF Mass Spectrometry: An Experiment for the Undergraduate Laboratory  

NASA Astrophysics Data System (ADS)

Matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) mass spectrometry has become a valuable tool for performing routine biochemical analyses. A common procedure for protein identification involves using tryptic digestion to obtain masses of individual peptides derived from the protein. The masses are compared against an online database, and probability-based scoring systems are used to determine the closest protein matches. This article describes an experiment we have developed for an undergraduate honors general chemistry laboratory to introduce students to state-of-the-art mass spectrometric methods. Students are given an overview of the theory and instrumentation associated with MALDI TOF, and gain hands-on experience with Internet tools for protein identification using mass spectral data. The experiment would be suitable for upper-division undergraduate laboratory courses as well; appropriate modifications for this purpose are also described.

Counterman, Anne E.; Thompson, Matthew S.; Clemmer, David E.

2003-02-01

369

[Inspection of laboratory animal breeding and husbandry/experiments on animals, examples].  

PubMed

In Berlin, the authorization and inspection of experiments on animals and of facilities for laboratory animal breeding and husbandry are carried out by the same authority. According to Section 16 (1) sentence one no. 3 Tierschutzgesetz (German animal protection act), there are presently 1200 procedures registered and 68 facilities approved to breed and keep vertebrates for experiments (according to Section 11 (1) sentence one no. 1 Tierschutzgesetz). In 2006, the use of 300,903 vertebrates was reported. There are 38 animal welfare officers in the twenty major scientific facilities who are in charge of in-house supervision. The authority visits the facilities where experiments take place at regular intervals to observe and supervise their operations. On request, the facilities must send the records from the experiments to the authority for examination (according to Section 9 a Tierschutzgesetz). With the annual laboratory animal report, the authority can verify the number of authorised laboratory animals. By checking the scientific publications the authority can compare them with the authorised animal experiments. Facilities for laboratory animal breeding and husbandry are continuously supervised. Offences against the animal protection act are prosecuted. When there are deficiencies in animal welfare, the authority sets a deadline to correct the defects. If the deficiency still exists after the expiry of the term, the authority imposes a penalty payment or initiates legal proceedings. The important role of the animal welfare officers (Section 8 a Tierschutzgesetz) is apparent. The majority of supervisions show that there are deficiencies. This indicates that more emphasis must be put on prevention. The facilities must provide better support and resources for the animal welfare officers. Furthermore, the scientists must be more receptive to the animal welfare officers in their role as advisers. Continuous and adequate training is imperative to the goal of maintaining sufficient in-house supervision and to keep the animals from suffering. If in-house supervision works well, the State's role in regulating animal experiments can be reduced. PMID:18500148

Ratsch, H

2008-04-01

370

Student Reciprocal Peer Teaching as a Method for Active Learning: An Experience in an Electrotechnical Laboratory  

NASA Astrophysics Data System (ADS)

Active learning is one of the most efficient mechanisms for learning, according to the psychology of learning. When students act as teachers for other students, the communication is more fluent and knowledge is transferred easier than in a traditional classroom. This teaching method is referred to in the literature as reciprocal peer teaching. In this study, the method is applied to laboratory sessions of a higher education institution course, and the students who act as teachers are referred to as "laboratory monitors." A particular way to select the monitors and its impact in the final marks is proposed. A total of 181 students participated in the experiment, experiences with laboratory monitors are discussed, and methods for motivating and training laboratory monitors and regular students are proposed. The types of laboratory sessions that can be led by classmates are discussed. This work is related to the changes in teaching methods in the Spanish higher education system, prompted by the Bologna Process for the construction of the European Higher Education Area

Muñoz-García, Miguel A.; Moreda, Guillermo P.; Hernández-Sánchez, Natalia; Valiño, Vanesa

2012-10-01

371

Off-state conductance measurements of the NIST/Lockheed Martin miniature pulse tube flight cryocooler: Laboratory vs. Space  

NASA Astrophysics Data System (ADS)

A two-stage miniature pulse tube (PT) cryocooler, designed for a Space Shuttle flight demonstration, was built and tested at Lockheed Martin Astronautics (LMA) and at the NIST Boulder Lab. The Miniature PT Flight Cryocooler (MPTFC) was designed to provide 0.15 W of cooling at 80 K with heat rejection at 275 K. It was developed as the smallest cryocooler of its kind for the purpose of demonstrating launch survivability and thermal performance in a zero-g environment. The flight version was fabricated as a Getaway Special (GAS) Payload. Although on-orbit cooling performance was not demonstrated because of failed primary batteries, the first off-state PT thermal conductance measurements in zero-g were conducted successfully using the secondary battery system. The data acquisition system and all flight diagnostic sensors performed nominally to provide 15 hours of zero-g warm-up data. The results of the cold head thermal conductance measurements both in zero-g aboard STS-90 and in the laboratory environment are compared to a thermal model for the two-stage PT, detailed in a separate presentation.

Ladner, D. R.; Radebaugh, R.; Bradley, P.

2002-05-01

372

Particle image velocimetry experiments for the IML-I spaceflight. [International Microgravity Laboratory  

NASA Technical Reports Server (NTRS)

The first International Microgravity Laboratory (IML-1), scheduled for spaceflight in early 1992 includes a crystal-growth-from-solution experiment which is equipped with an array of optical diagnostics instrumentation which includes transmission and reflection holography, tomography, schlieren, and particle image displacement velocimetry. During the course of preparation for this spaceflight experiment we have performed both experimentation and analysis for each of these diagnostics. In this paper we describe the work performed in the development of holographic particle image displacement velocimetry for microgravity application which will be employed primarily to observe and quantify minute convective currents in the Spacelab environment and also to measure the value of g. Additionally, the experiment offers a unique opportunity to examine physical phenomena which are normally negligible and not observable. A preliminary analysis of the motion of particles in fluid was performed and supporting experiments were carried out. The results of the analysis and the experiments are reported.

Trolinger, J. D.; Lal, R. B.; Batra, A. K.; Mcintosh, D.

1991-01-01

373

Laboratory evaporation experiments in undisturbed peat columns for determining peat soil hydraulic properties  

NASA Astrophysics Data System (ADS)

Knowledge about hydraulic properties of organic soils is crucial for the interpretation of the hydrological situation in peatlands. This in turn is the basis for designing optimal rewetting strategies, for assessing the current and future climatic water balance and for quantifying greenhouse gas emissions of CO2, CH4 and N2O, which are strongly controlled by the depth of the peat water table. In contrast to mineral soils, the hydraulic properties of organic soils differ in several aspects. Due to the high amount of organic components, strong heterogeneity, and shrinkage and swelling of peat, accompanied by changing soil volume and bulk density, the applicability of standard hydraulic functions developed for mineral soils for describing peat soil moisture dynamics is often questioned. Hence, the objective of this study was to investigate the applicability of the commonly applied van Genuchten-Mualem (VGM) parameterization and to evaluate model errors for various peat types. Laboratory column experiments with undisturbed peat soils (diameter: 30 cm, height: 20 cm) from 5 different peatlands in Germany were conducted. In numerical simulations using HYDRUS-1D the experimental data were used for an inverse estimation of the soil hydraulic parameters. Using the VGM parameterization, the model errors between observed and measured pressure heads were quantified with a root mean square error (RMSE) of 20 - 65 cm. The RMSE increased for soils with higher organic carbon content and higher porosity. Optimizing the VGM 'tortuosity' parameter (?) instead of fixing it to its default of 0.5 strongly reduced the RMSE, especially for the soils that showed high pressure head gradients during the experiment. Due to the fact, that very negative pressure heads in peatlands occur rarely, we reduced the range of pressured heads in the inversion to a 'field-relevant' range from 0 to -200 cm which strongly reduced the RMSE to 6 - 12 cm and makes the VGM parameterization applicable for all investigated peat soils. For the field-relevant scale, especially for very wet conditions, we demonstrate the importance of macro-pores by using a simple macro-pore approach, with only 1 additional parameter, i.e. the macro-pore fraction, which strongly reduced the RMSE down to 1 - 7 cm. Since ? has not been identified as an important parameter for the field-relevant range, only 5 parameters were optimized in this approach. This keeps the derivation of the parameters manageable and thus provides a model that is applicable to practical issues.

Dettmann, U.; Frahm, E.; Bechtold, M.

2013-12-01

374

Experiment 36 Extraterrestrial microwaves Place : ML-laboratory, lab at the end of the flight-time tunnel  

E-print Network

0 Experiment 36 ­ Extraterrestrial microwaves Place : ML-laboratory, lab at the end of the flight'clock in order to finish the exercises in time. #12;1 Experiment 36 Extraterrestrial microwaves 1. Historical

375

Onset of a perched water table during infiltration in a gradually layered soil: Reanalysis of a laboratory experiment  

NASA Astrophysics Data System (ADS)

Perched water tables in the upper soil layers play a key role in water partitioning during infiltration. They are typically thin and ephemeral, and onset in soils where a decrease of hydraulic conductivity and diffusivity is observed with depth. Aiming at better understanding their dynamics, we theoretically and numerically reanalysed a laboratory experiment, during which the onset of a perched water table was observed in a reconstructed soil with gradually decreasing conductivity at saturation with depth. The laboratory prototype was a prismatic column filled with 9 different 0.1 m--deep soil layers. The grain--size distribution curve and porosity of the layers were designed in order to reproduce an exponential decay of conductivity, on the basis of the application of a modified Kozeny--Carman relationship. During the experiment the soil was artificially wetted by means of a rainfall simulator at a rate previously determined in order to maintain a constant water content on the surface for 9 hours. Istantaneous volumetric water content profiles were measured by means of 9 multiplexed TDR probes. As a result of the experiment a water content peak was observed below the soil surface. Then it emphasised and moved downward until a perched water table formed at an intermediate height in the column, about 6 h after the beginning of the experiment. The thickness of the perched water table rapidly increased upward while the wetting front slowly travelled downward. The observed patterns supported phenomenological aspects enlightened by an analytical solution of transient infiltration in a gradually layered soil and by a numerical solution of similar cases. When the perched water table onset, the infiltration was quantitatively compatible with the presence of a perched water table within the soil column, on the basis of a steady infiltration theoretical framework. Then a reanalysis of the experiment was performed by numerically solving the Richards equation for a multilayered porous medium with a classical van Genuchten--Mualem conceptualisation of the soil--water constitutive laws. Due to the great number of involved soil parameters, we chose a deterministic approach with a minimum calibration of the dry--soil initial conditions. The reanalysis allowed to fairly describe the water content dynamics, and the obtained tensiometer--pressure potential profiles were found in good agreement with a steady solution of the saturated layer.

Barontini, Stefano; Grottolo, Maria; Belluardo, Giorgio; Bacchi, Baldassare; Ranzi, Roberto

2014-05-01

376

Solute and heat transport model of the Henry and hilleke laboratory experiment.  

PubMed

SEAWAT is a coupled version of MODFLOW and MT3DMS designed to simulate variable-density ground water flow and solute transport. The most recent version of SEAWAT, called SEAWAT Version 4, includes new capabilities to represent simultaneous multispecies solute and heat transport. To test the new features in SEAWAT, the laboratory experiment of Henry and Hilleke (1972) was simulated. Henry and Hilleke used warm fresh water to recharge a large sand-filled glass tank. A cold salt water boundary was represented on one side. Adjustable heating pads were used to heat the bottom and left sides of the tank. In the laboratory experiment, Henry and Hilleke observed both salt water and fresh water flow systems separated by a narrow transition zone. After minor tuning of several input parameters with a parameter estimation program, results from the SEAWAT simulation show good agreement with the experiment. SEAWAT results suggest that heat loss to the room was more than expected by Henry and Hilleke, and that multiple thermal convection cells are the likely cause of the widened transition zone near the hot end of the tank. Other computer programs with similar capabilities may benefit from benchmark testing with the Henry and Hilleke laboratory experiment. PMID:19563419

Langevin, Christian D; Dausman, Alyssa M; Sukop, Michael C

2010-01-01

377

Summary of activities of the life cycle costing workshop conducted by the Environmental Restoration Program of Oak Ridge National Laboratory  

SciTech Connect

A five-day life cycle workshop was conducted by the Environmental Restoration (FR) Program of Oak Ridge National Laboratory (ORNL) to develop appropriate remediation scenarios for each Waste Area Grouping (WAG) at ORNL and to identify associated data needs (e.g., remedial investigations, special studies, and technology demonstrations) and required interfaces. Workshop participants represented the Department of Energy, Martin Marietta Energy Systems, Inc., Bechtel National, Radian Corporation, EBASCO Corporation, and M-K Ferguson. The workshop was used to establish a technical basis for remediation activities at each WAG. The workshop results are documented in this report and provide the baseline for estimating the technical scope for each WAG. The scope and associated budgets and schedules will be summarized in baseline reports for each WAG, which, in turn, will be compiled into an overall strategy document for ORNL ER.

Not Available

1992-08-01

378

Analytical Plans Supporting The Sludge Batch 8 Glass Variability Study Being Conducted By Energysolutions And Cua's Vitreous State Laboratory  

SciTech Connect

EnergySolutions (ES) and its partner, the Vitreous State Laboratory (VSL) of The Catholic University of America (CUA), are to provide engineering and technical services support to Savannah River Remediation, LLC (SRR) for ongoing operation of the Defense Waste Processing Facility (DWPF) flowsheet as well as for modifications to improve overall plant performance. SRR has requested via a statement of work that ES/VSL conduct a glass variability study (VS) for Sludge Batch 8. SRR issued a technical task request (TTR) asking that the Savannah River National Laboratory (SRNL) provide planning and data reduction support for the ES/VSL effort. This document provides two analytical plans for use by ES/VSL: one plan is to guide the measurement of the chemical composition of the study glasses while the second is to guide the measurement of the durability of the study glasses. The measurements generated by ES/VSL are to be provided to SRNL for data reduction and evaluation. SRNL is to review the results of its evaluation with ES/VSL and SRR. The results will subsequently be incorporated into a joint report with ES/VSL as a deliverable to SRR to support the processing of SB8 at DWPF.

Edwards, T. B.; Peeler, D. K.

2012-11-26

379

Effects of charcoal addition on N2O emissions from soil resulting from rewetting air-dried soil in short-term laboratory experiments  

Microsoft Academic Search

Laboratory experiments were conducted to examine the effect of charcoal addition on N2O emissions resulting from rewetting of air-dried soil. Rewetting the soil at 73% and 83% of the water-filled pore space (WFPS) caused a N2O emission peak 6 h after the rewetting, and the cumulative N2O emissions throughout the 120-h incubation period were 11 ± 1 and 13 ± 1 mg N m, respectively. However, rewetting at

Yosuke Yanai; Koki Toyota; Masanori Okazaki

2007-01-01

380

COOK-OFF EXPERIMENTS FOR MODEL VALIDATION AT SANDIA NATIONAL LABORATORIES  

Microsoft Academic Search

We have conducted a series of experiments to investigate the process of thermal ignition of energetic materials during slow cook-off, for the primary purpose of validation of models used to simulate this process. Pellets of PBX-9501 and PBXN-109 were heated inside a sealed aluminum cell and the internal temperature field was monitored with a grid of thermocouples. Comparison of these

Michael J. Kaneshige; Anita M. Renlund; Robert G. Schmitt; William W. Erikson

381

FSL: a fluid science laboratory for the International Space Station - the software Environment for the experiment execution  

NASA Astrophysics Data System (ADS)

The FSL (Fluid Science Laboratory) is a flexible, highly modular facility for the COF (Columbus Orbital Facility) - the European module of the International Space Station (ISS) - to support scientific microgravity research in fluid physics. Housed in an International Standard Payload Rack (ISPR), FSL will allow triggering and observation of phenomena inside transparent fluid matrices and at the surface of opaque media. Some possible FSL experiment fields are: Fluid convection and heat transfer, Marangoni motion of inclusions (drops or bubbles) in fluid matrix, Liquid bridges in fluid or gas matrix, Experiments on boiling, Experiments on critical point, Melting and solidification front and interaction with inclusions, Coalescence, Multilayer systems, Colloids, emulsions and aerosols, Particle agglomeration, Plasma crystal physics. The FSL is developed under contract with the European Space Agency (ESA). Alenia Spazio S.p.A. Turin (I) is Prime Contractor for the project. This paper briefly addresses the FSL architecture, then focuses on the set of instrumentation, services and utilities provided to the user to conceive, develop and conduct experiments, focusing in particular on the on-board software environment.

Pensavalle, Emanuele; Trinchero, Giorgio

2002-07-01

382

Modeling Laboratory Astrophysics Experiments in the High-Energy-Density Regime Using the CRASH Radiation-Hydrodynamics Model  

NASA Astrophysics Data System (ADS)

The radiation hydrodynamics code developed by the Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan has been used to model experimental designs for high-energy-density physics campaigns on OMEGA and other high-energy laser facilities. This code is an Eulerian, block-adaptive AMR hydrodynamics code with implicit multigroup radiation transport and electron heat conduction. CRASH model results have shown good agreement with a experimental results from a variety of applications, including: radiative shock, Kelvin-Helmholtz and Rayleigh-Taylor experiments on the OMEGA laser; as well as laser-driven ablative plumes in experiments by the Astrophysical Collisionless Shocks Experiments with Lasers (ACSEL), collaboration. We report a series of results with the CRASH code in support of design work for upcoming high-energy-density physics experiments, as well as comparison between existing experimental data and simulation results. This work is funded by the Predictive Sciences Academic Alliances Program in NNSA-ASC via grant DEFC52- 08NA28616, by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-FG52-09NA29548, and by the National Laser User Facility Program, grant number DE-NA0000850.

Grosskopf, M. J.; Drake, R. P.; Trantham, M. R.; Kuranz, C. C.; Keiter, P. A.; Rutter, E. M.; Sweeney, R. M.; Malamud, G.

2012-10-01

383

MIT Lincoln LaboratoryHTS: MTI-UAV Cueing Experiment LAB/RAK 1/24/2006  

E-print Network

MIT Lincoln LaboratoryHTS: MTI-UAV Cueing Experiment LAB/RAK 1/24/2006 Lawrence Bush 2006 January 24 Semi-Automated Cueing of Predator UAV Operators from RADAR Moving Target (MTI) Data MIT Lincoln and are not necessarily endorsed by the United States Government. #12;MIT Lincoln LaboratoryHTS: MTI-UAV Cueing Experiment

Cummings, Mary "Missy"

384

Engineering Evaluation of Proposed Alternative Salt Transfer Method for the Molten Salt Reactor Experiement for the Oak Ridge National Laboratory  

Microsoft Academic Search

This evaluation was performed by Pro2Serve in accordance with the Technical Specification for an Engineering Evaluation of the Proposed Alternative Salt Transfer Method for the Molten Salt Reactor Experiment at the Oak Ridge National Laboratory (BJC 2009b). The evaluators reviewed the Engineering Evaluation Work Plan for Molten Salt Reactor Experiment Residual Salt Removal, Oak Ridge National Laboratory, Oak Ridge, Tennessee

Jon A. Carlberg; Kenneth T. Roberts; Thomas G. Kollie; Leslie E. Little; Sherman D. Brady

2009-01-01

385

Inquiry-Based Laboratory Course Improves StudentsÂ? Ability to Design Experiments and Interpret Data  

NSDL National Science Digital Library

We redesigned our intermediate-level organismal physiology laboratory course to center on student-designed experiments in plant and human physiology. Our primary goals were to improve the ability of students to design experiments and analyze data. We assessed these abilities at the beginning and end of the semester by giving students an evaluation tool consisting of an experimental scenario, data, and four questions of increasing complexity. The laboratory lecture group improved more than the lecture-only group for the most challenging question. This evidence suggests that our inquiry-based curriculum is achieving its primary goals. The evaluation tool that we developed may be useful to others interested in measuring experimental analysis abilities in their students.

Marcella J. Myers (College of St. Catherine Department of Biology)

2003-03-01

386

Laboratory experiments in the study of the chemistry of the outer planets.  

PubMed

The investigation of chemical evolution of bodies in our solar system has, in the past, included observations, theoretical modeling, and laboratory simulations. Of these programs, the last one has been the most criticized due to the inherent difficulties in accurately recreating alien environments in the laboratory. Processes such as wall reactions and changes in chemistry due to difficulties in achieving realistic conditions of temperature, pressure, composition, and energy flux may yield results which are not truly representative of the systems being modeled. However, many laboratory studies have been done which have yielded data useful in planetary science. Gross simulations of atmospheric chemistry have placed constraints on the nature of complex molecules expected in planetary atmospheres. More precise studies of specific chemical processes have provided information about the sources and properties of product gases and aerosols. Determinations of basic properties such as spectral features and reaction rate constants yield data useful in the interpretation of observations and in computational modeling. Alone, and in conjunction with modeling, laboratory experiments will continue to be used to further our understanding of the outer solar system, and some experiments that need to be done are listed. PMID:11538221

Scattergood, T W

1987-01-01

387

Validation experiment of a numerically processed millimeter-wave interferometer in a laboratory  

SciTech Connect

We propose a new interferometer system for density profile measurements. This system produces multiple measurement chords by a leaky-wave antenna driven by multiple frequency inputs. The proposed system was validated in laboratory evaluation experiments. We confirmed that the interferometer generates a clear image of a Teflon plate as well as the phase shift corresponding to the plate thickness. In another experiment, we confirmed that quasi-optical mirrors can produce multiple measurement chords; however, the finite spot size of the probe beam degrades the sharpness of the resulting image.

Kogi, Y., E-mail: kogi@fit.ac.jp; Higashi, T.; Matsukawa, S. [Department of Information Electronics, Fukuoka Institute of Technology, Fukuoka 811-0295 (Japan); Mase, A. [Art, Science and Technology Center for Cooperative Research, Kyushu University, Kasuga, Fukuoka 816-0811 (Japan); Kohagura, J.; Yoshikawa, M. [Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Nagayama, Y.; Kawahata, K. [National Institute for Fusion Science, Toki, Gifu 509-5202 (Japan); Kuwahara, D. [Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan)

2014-11-15

388

A landmark recognition and tracking experiment for flight on the Shuttle/Advanced Technology Laboratory (ATL)  

NASA Technical Reports Server (NTRS)

The preliminary design of an experiment for landmark recognition and tracking from the Shuttle/Advanced Technology Laboratory is described. It makes use of parallel coherent optical processing to perform correlation tests between landmarks observed passively with a telescope and previously made holographic matched filters. The experimental equipment including the optics, the low power laser, the random access file of matched filters and the electro-optical readout device are described. A real time optically excited liquid crystal device is recommended for performing the input non-coherent optical to coherent optical interface function. A development program leading to a flight experiment in 1981 is outlined.

Welch, J. D.

1975-01-01

389

Laboratory experiments for understanding the chemical evolution of organic matter in astrophysical ices  

NASA Astrophysics Data System (ADS)

The challenges of our projects consist in simulating through laboratory experiments, the chemical evolution of astrophysical ices for understanding what could be the different stages of the organic matter during the life cycle of interstellar grains to their incorporation in planetary systems such as in comets or in asteroids inside the Solar System. Our experiments consist in recreating primitive or cometary ices evolution, which allow obtaining data on the chemical reactivity that occur during the evolution process (RING project), the characterization of species sublimating during the ice warming (VAHIIA project), as well as on refractory residue (RAHIIA project). All these results can then serve for space missions.

Danger, G.; Duvernay, F.; Vinogradoff, V.; Theulé, P.; Chiavassa, C.

2013-09-01

390

Investigation of Model Cell Membranes with Raman Spectroscopy: A Biochemistry Laboratory Experiment  

NASA Astrophysics Data System (ADS)

New developments that extend the usefulness of Raman spectroscopy for the investigation of biological systems are described. One of these methods, excitation with a near-infrared laser at 1064 nm and detection with a Fourier transform infrared spectrometer, is applied to the investigation of temperature profiles of dispersions of phospholipids in water. These dispersions are models of biomembranes. This experiment for the undergraduate biochemisty laboratory gives students experience applying vibrational spectroscopy to the investigation of the molecular properties of biomembranes. The basis of the Raman effect is reviewed.

Craig, Norman C.; Fuchsman, William H.; Lacuesta, Nanette N.

2003-11-01

391

First Results from the XENON10 Dark Matter Experiment at the Gran Sasso National Laboratory  

Microsoft Academic Search

The XENON10 experiment at the Gran Sasso National Laboratory uses a 15 kg xenon dual phase time projection chamber to search for dark matter weakly interacting massive particles (WIMPs). The detector measures simultaneously the scintillation and the ionization produced by radiation in pure liquid xenon to discriminate signal from background down to 4.5 keV nuclear-recoil energy. A blind analysis of

J. Angle; E. Aprile; F. Arneodo; L. Baudis; A. Bernstein; A. Bolozdynya; P. Brusov; L. C. C. Coelho; C. E. Dahl; L. Deviveiros; A. D. Ferella; L. M. P. Fernandes; S. Fiorucci; R. J. Gaitskell; K. L. Giboni; R. Gomez; R. Hasty; L. Kastens; J. Kwong; J. A. M. Lopes; N. Madden; A. Manalaysay; A. Manzur; D. N. McKinsey; M. E. Monzani; K. Ni; U. Oberlack; J. Orboeck; G. Plante; R. Santorelli; J. M. F. Dos Santos; P. Shagin; T. Shutt; P. Sorensen; S. Schulte; C. Winant; M. Yamashita

2008-01-01

392

Nitrogenous preference of toxigenic Pseudo-nitzschia australis (Bacillariophyceae) from field and laboratory experiments  

Microsoft Academic Search

Field and laboratory experiments were designed to determine the differential growth and toxin response to inorganic and organic nitrogen additions in Pseudo-nitzschia spp. Nitrogen enrichments of 50?M nitrate (KNO3), 10?M ammonium (NH4Cl), 20?M urea and a control (no addition) were carried out in separate carboys with seawater collected from the mouth of the San Francisco Bay (Bolinas Bay), an area

Meredith D. Armstrong Howard; William P. Cochlan; Nicolas Ladizinsky; Raphael M. Kudela

2007-01-01

393

The tensile strength of the cometary surface: Laboratory experiments and implications on formation scenarios  

NASA Astrophysics Data System (ADS)

One big question in cometary physics is how the gas pressure can overcome the tensile strength of the surface material to effectively release dust from the cometary surface. Thus, we have performed laboratory experiments in order to measure the tensile strength of the cometary surface by using silica aggregates as an analog sample material. During this conference we would like to present our experimental results and to discuss how different formation scenarios can have influenced the activity of comets.

Gundlach, B.; Blum, J.

2014-07-01

394

Viscosity, electrical conductivity, and cesium volatility of ORNL (Oak Ridge National Laboratory) vitrified soils with limestone and sodium additives  

SciTech Connect

Engineering- and pilot-scale tests of the in situ vitrification (ISV) process have been conducted for Oak Ridge National Laboratory (ORNL) to successfully demonstrate the feasibility of applying ISV to seepage trenches and pits at ORNL. These sites contain soil that overlies crushed limestone fill; therefore, the ISV process is applied to a soil-limestone mixture. Previous testing indicated that while a good retention level of {sup 137}Cs and {sup 90}Sr was achieved in the melt, it would be desirable to improve {sup 137}Cs retention to 99.99% if possible to minimize activity in the off-gas system. Previous testing was limited to one soil-limestone composition. Both Cs volatility and ISV power requirements are in part dependent on melt temperature and viscosity, which depend on melt composition. The study described in this report determined the effect of varying soil and limestone compositions, as well as the addition of a sodium flux, on melt viscosity, electrical conductivity, and Cs volatility. 10 refs., 15 figs., 9 tabs.

Shade, J.W.; Piepel, G.F.

1990-05-01

395

Effect of Biochar on Greenhouse Gas Emissions and Nitrogen Cycling in Laboratory and Field Experiments  

NASA Astrophysics Data System (ADS)

The extensive use of nitrogen (N) fertilizers in agriculture is a major source of anthropogenic N2O emissions contributing 8% to global greenhouse gas emissions. Soil biochar amendment has been suggested as a means to reduce both CO2 and non-CO2 greenhouse gas emissions. The reduction of N2O emissions by biochar has been demonstrated repeatedly in field and laboratory experiments. However, the mechanisms of the reduction remain unclear. Further it is not known how biochar field-weathering affects GHG emissions and how agro-chemicals, such as the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP), that is often simultaneously applied together with commercial N-fertilizers, impact nitrogen transformation and N2O emissions from biochar amended soils. In order investigate the duration of the biochar effect on soil N2O emissions and its susceptibility to DMPP application we performed a microcosm and field study with a high-temperature (400 ° C) beech wood derived biochar (60 t ha-1 and 5 % (w/w) biochar in the field and microcosms, respectively). While the field site contained the biochar already for three years, soil and biochar were freshly mixed for the laboratory microcosm experiments. In both studies we quantified GHG emissions and soil nitrogen speciation (nitrate, nitrite, ammonium). While the field study was carried out over the whole vegetation period of the sunflower Helianthus annuus L., soil microcosm experiments were performed for up to 9 days at 28° C. In both experiments a N-fertilizer containing DMPP was applied either before planting of the sunflowers or at the beginning of soil microcosms incubation. Laboratory microcosm experiments were performed at 60% water filled pore space reflecting average field conditions. Our results show that biochar effectively reduced soil N2O emissions by up to 60 % in the field and in the soil microcosm experiments. No significant differences in N2O emission mitigation potential between field-aged and fresh biochar were observed for the specific biochar used in this study. N2O emission reduction occurred even in the presence of DMPP in the field and in the laboratory microcosms. Our results suggest that simultaneous measurements of soil samples from the same field site in the laboratory yield similar biochar effects to those quantified in the field and that the mechanisms of N2O mitigation seem to be independent of plant growth and application of the commercial nitrification inhibitor DMPP.

Hagemann, Nikolas; Harter, Johannes; Kaldamukova, Radina; Ruser, Reiner; Graeff-Hönninger, Simone; Kappler, Andreas; Behrens, Sebastian

2014-05-01

396

Laboratory-Measured and Property-Transfer Modeled Saturated Hydraulic Conductivity of Snake River Plain Aquifer Sediments at the Idaho National Laboratory, Idaho  

USGS Publications Warehouse

Sediments are believed to comprise as much as 50 percent of the Snake River Plain aquifer thickness in some locations within the Idaho National Laboratory. However, the hydraulic properties of these deep sediments have not been well characterized and they are not represented explicitly in the current conceptual model of subregional scale ground-water flow. The purpose of this study is to evaluate the nature of the sedimentary material within the aquifer and to test the applicability of a site-specific property-transfer model developed for the sedimentary interbeds of the unsaturated zone. Saturated hydraulic conductivity (Ksat) was measured for 10 core samples from sedimentary interbeds within the Snake River Plain aquifer and also estimated using the property-transfer model. The property-transfer model for predicting Ksat was previously developed using a multiple linear-regression technique with bulk physical-property measurements (bulk density [pbulk], the median particle diameter, and the uniformity coefficient) as the explanatory variables. The model systematically underestimates Ksat,typically by about a factor of 10, which likely is due to higher bulk-density values for the aquifer samples compared to the samples from the unsaturated zone upon which the model was developed. Linear relations between the logarithm of Ksat and pbulk also were explored for comparison.

Perkins, Kim S.

2008-01-01

397

Laboratory Study to Identify the Impact of Fracture Design Parameters over the Final Fracture Conductivity Using the Dynamic Fracture Conductivity Test Procedure  

E-print Network

such as closure stress, and temperature and fracture fluid parameters such as proppant loading over the final conductivity of a hydraulic fracture treatment. With the purpose of estimating the relation between fracture conductivity and the design parameters, two...

Pieve La Rosa, Andres Eduardo

2011-08-08

398

Transposing from the laboratory to the classroom to generate authentic research experiences for undergraduates.  

PubMed

Large lecture classes and standardized laboratory exercises are characteristic of introductory biology courses. Previous research has found that these courses do not adequately convey the process of scientific research and the excitement of discovery. Here we propose a model that provides beginning biology students with an inquiry-based, active learning laboratory experience. The Dynamic Genome course replicates a modern research laboratory focused on eukaryotic transposable elements where beginning undergraduates learn key genetics concepts, experimental design, and molecular biological skills. Here we report on two key features of the course, a didactic module and the capstone original research project. The module is a modified version of a published experiment where students experience how virtual transposable elements from rice (Oryza sativa) are assayed for function in transgenic Arabidopsis thaliana. As part of the module, students analyze the phenotypes and genotypes of transgenic plants to determine the requirements for transposition. After mastering the skills and concepts, students participate in an authentic research project where they use computational analysis and PCR to detect transposable element insertion site polymorphism in a panel of diverse maize strains. As a consequence of their engagement in this course, students report large gains in their ability to understand the nature of research and demonstrate that they can apply that knowledge to independent research projects. PMID:23172853

Burnette, James M; Wessler, Susan R

2013-02-01

399

Management of the preanalytical phase: experience of the microbiology laboratory of "Fattouma Bourguiba" hospital of Monastir.  

PubMed

We propose in this work to study the details of the preanalytical phase (PAP) in microbiology, in order to determinate gaps with the requirement of Good laboratory practice guideline (GLPG), causes of dysfunction and actions to improve its quality in our establishment. Methods: This Study was carried out in the microbiology laboratory of the University Hospital of Monastir. We conducted a self-assessment grid and a satisfaction survey phlebotomist staff. A literature review was conducted in accordance with the requirements of normative and regulatory documents (ISO 15189 standard and GLPG). The analysis of non-conformities was performed by the method of 5M and the risk analysis by the preliminary risk analysis (PRA). Results: The results show that the fault lies primarily in the management of human resources. The cause analysis puts the focus on a lack of awareness and training of the responsible staff. Risk analysis reveals another failure in the communication between laboratory and clinicians, and in the formulation of methods (procedures, instructions…). Conclusion: The Study of the PPA in details shows that all steps are critical. Indeed, the management of this phase requires the application of the requirements of the GLPG and awareness of a total quality management. PMID:25336137

Elargoubi, Aida; Mastouri, Maha; Najjar, Mohamed Fadhel

2014-10-01

400

Fundamental processes in the expansion, energization, and coupling of single- and multi-Ion plasmas in space: Laboratory simulation experiments  

NASA Technical Reports Server (NTRS)

We have conducted a laboratory investigation into the physics of plasma expansions and their associated energization processes. We studied single- and multi-ion plasma processes in self-expansions, and included light and heavy ions and heavy/light mixtures to encompass the phenomenological regimes of the solar and polar winds and the AMPTE and CRRES chemical release programs. The laboratory experiments provided spatially-distributed time-dependent measurements of total plasma density, temperature, and density fluctuation power spectra with the data confirming the long-theorized electron energization process in an expanding cloud - a result that was impossible to determine in spaceborne experiments (as e.g., in the CRRES program). These results provided the missing link in previous laboratory and spaceborne programs. confirming important elements in our understanding of such solar-terrestrial processes as manifested in expanding plasmas in the solar wind (e.g., CMES) and in ionospheric outflow in plasmaspheric fluctuate refilling after a storm. The energization signatures were seen in an entire series of runs that varied the ion species (Ar', Xe', Kr' and Ne'), and correlative studies included spectral analyses of electrostatic waves collocated with the energized electron distributions. In all cases wave energies were most intense during the times in which the suprathermal populations were present, with wave intensity increasing with the intensity of the suprathermal electron population. This is consistent with theoretical expectations wherein the energization process is directly attributable to wave particle interactions. No resonance conditions were observed, in an overall framework in which the general wave characteristics were broadband with power decreasing with increasing frequency.

Szuszczewicz, E. P.; Bateman, T. T.

1996-01-01

401

The role of electron heat conductivity and radiation transport in 1D simulations of wire explosions in Zebra experiments  

Microsoft Academic Search

Experiments at the Zebra facility at the University of Nevada, Reno, have been conducted to study the behavior of thick metal wires at ultrahigh magnetic fields. Currents of about 1 MA with 100 ns rise time were passed through 0.5 mm to 2 mm diameter aluminum wires. A number of diagnostic techniques used in the experiments provided data on radial

S. F. Garanin; S. D. Kuznetsov

2009-01-01

402

CO2 Field Laboratory at Svelvik Ridge: Site characterization after the first injection experiment  

NASA Astrophysics Data System (ADS)

The safety and acceptance of CO2 storage will depend on the ability to detect and quantify CO2 within and outside the storage complex. To determine sensitivity of CO2 monitoring systems with respect to CO2 distribution and leakage detection, the CO2 Field Lab project comprises two controlled CO2 injection tests in the shallow (100-300 m) and very shallow (20 m) subsurface of the glacial deposit that forms Svelvik ridge, 50 km south of Oslo. The CO2 displacement in the subsurface and at the surface has and will be monitored with an exhaustive set of techniques. Iteratively, observations and flow modeling will provide frequent updates of the CO2 distribution. The results will be upscaled to assess monitoring systems and requirements with the ultimate objective to provide guidelines to regulators, operators and technology providers for monitoring systems. The formation that comprises the laboratory is a glaciofluvial-glaciomarine terminal deposit formed during the Ski stage of the Holocene deglaciation. Nearby outcrops show that the formation is channeled and variably laminated with a significant variation in grain size and structure. Prior to the injection experiments, the site was characterized including 2D seismic and electric surveys, the drilling, logging and sampling of a 330 m deep appraisal well, core and flow line sample analyses, ground penetrating radar (GPR), a hydrodynamic appraisal, and geochemical and soil gas baseline surveys. These data were used to populate a geomodel. Flow modeling of the plume development included some variability in permeability and anisotropy, and various injection scenarios. Accordingly, the 20 m injection experiment was conducted in fall 2011 with a monitoring plan designed to spatially and temporally monitor the expected plume development. The monitoring equipment was thus distributed around the 20 m deep injection point of an inclined well. It included seven 6 m deep monitoring wells equipped with resistivity, sonic and geochemical logging tools, with GPR, and water samplers. Surface monitoring included stationary and mobile tools for geochemical analyses of ground water, soil and atmospheric gas. Even though the trajectory of migrating CO2 deviated somewhat from the predictions, most stationary monitoring techniques picked up some trace of the CO2 plume. The surfacing CO2 flow was measured most precisely since the mobile surface stations were (re-)located over the leakage areas. After the injection test, numerous sediment samples were taken at various depths and locations around the injection point. Together with the monitoring results, these data are used to better characterize the site and to update the geological and flow model for improved interpretation of the experiments. The results show that accurate information on the stratigraphic variability is of outmost importance for understanding possible pathways of CO2 in the shallow subsurface.

Buddensiek, M. L.; Lindeberg, E.; Mørk, A.; Jones, D.; Girard, J. F.; Kuras, O.; Barrio, M.; Royse, K.; Gal, F.; Meldrum, P.; Pezard, P.; Levannier, A.; Desroches, J.; Neyens, D.; Paris, J.; Henry, G.; Bakk, A.; Wertz, F.; Aker, E.; Børresen, M.

2012-04-01

403

Safety analysis report for the Hanford Critical Mass Laboratory: Supplement No. 2. Experiments with heterogeneous assemblies  

SciTech Connect

Factors affecting the safety of criticality experiments using heterogeneous assemblies are described and assessed. It is concluded that there is no substantial change in safety from experiments already being routinely performed at the Critical Mass Laboratory (CML), and that laboratory and personnel safety are adequately provided by the combination of engineered and administrative safety limits enforced at the CML. This conclusion is based on the analysis of operational controls, potential hazards, and the consequences of accidents. Contingencies considered that could affect nuclear criticality include manual changes in fuel loadings, water flooding, fire, explosion, loss of services, earthquake, windstorm, and flood. Other potential hazards considered include radiation exposure to personnel, and potential releases within the Assembly Room and outside to the environment. It is concluded that the Maximum Credible Nuclear Burst of 3 x 10/sup 18/ fissions (which served as the design basis for the CML) is valid for heterogeneous assemblies as well as homogeneous assemblies. This is based upon examination of the results of reactor destructive tests and the results of the SL-1 reactor destructive accident. The production of blast effects which might jeopardize the CML critical assembly room (of thick reinforced concrete) is not considered credible due to the extreme circumstances required to produce blast effects in reactor destructive tests. Consequently, it is concluded that, for experiments with heterogeneous assemblies, the consequences of the Maximum Credible Burst are unchanged from those previously estimated for experiments with homogeneous systems.

Gore, B.F.; Davenport, L.C.

1981-04-01

404

Meta-instable Stress States and Faulting Synergy from Laboratory Experiments  

NASA Astrophysics Data System (ADS)

As a possible mechanism of earthquake, stick-slip has long been studied in laboratory, but little has been studied in detail for the last period of a fault approaching to its instability, in which the general differential stress drops from the peak-value of tectonic stress to the level at the beginning of final instability. We define this short-period as a meta-instable stage. In laboratory, the mechanic sign of whether a sample enters meta-instability state is that the stress released rate transfers from a slow velocity to a fast one. Thus, identifying the meat-instable stress state is theoretically and practically important for potential seismic risk evaluation. In order to obtain a detailed evolution process of meta-instable stage, we conducted a series of experiments with different types of combined faults by use of four types of sensor arrays to record strain, fault displacement, acoustic emission and temperature as well as an infrared thermal image system. Furthermore, digital images of sample surface were taken, by high-speed camera at the sampling rate of 1 kHz during stick-slip, to calculate fault displacement field of sample surface. We compared these multi-physical phenomena during different strike-slip stages, including stress accumulation, deviating linear increase of stress, meta-instability and instability. The preliminary results show as following: (i) The instability of a fault is a converting process from independent activities to synergetic activities; the instability is the end of the synergy, while the synergy of different segments of a fault is a sign of regional stress release; (ii) At the beginning of stress release, the stress deviate the linear trend; it is a transition stage from stress accumulation to stress release, while the release is not dominant; and non-linear temperature change caused by strain is observed. We find a shift pattern of compressive and tensional regions, which is reciprocating to extend along the fault from both the strain fields and the thermal fields associated with volumetric strain. (iii) In the meta-instable stage, the stress release is gradually dominated and the synergy is approaching to complete; the more the system is closer to the instability, the less the change induced by strain will be, and the release due to displacement consequently increases; It is notable that a rapid increase of synergetic level of fault displacement presents, whereas less strain change is observed. The fault dislocations started from multi-point and extended to both sides of the fault appear acceleration synergy before instability presents in the infrared thermal images. (iv) The duration time of meta-instable stage for planar faults is less than those of bending faults and compressive en echelon faults. All these observations indicate synergy is an important process in meta-instable stage, and might give new insights into the regional stress state evaluation.

Ma, J.; Guo, Y.; Zhuo, Y.; Ren, Y.; Zhang, K.; Liu, G.

2012-12-01

405

On improving rainfall and solid precipitation weighing-gauge measurements using laboratory experiments  

NASA Astrophysics Data System (ADS)

Short interval snowfall, drizzle and light rainfall events can be hard to measure with precipitation gauges due to sampling limitations, wind effects, and noise. The noise observed in the data sampling can often be greater than the detectable signal from a real precipitation event. In addition wind effects can induce differential air pressure on the measurement devices inside the gauges increasing the signal noise. Various algorithms have been devised to help reduce noise and other unwanted effects in precipitation gauge measurements. Most of these algorithms have focused on the removal of wind effects, while others have focused on reducing temperature dependencies. Recent laboratory testing has demonstrated the ability to reproduce some of these anomalies observed in precipitation measurements during field trial campaigns. Assessing the factors contributing to these anomalies is required to accurately simulate these conditions in the laboratory. It is also important to understand these factors to support the selection of the appropriate natural conditions to be simulated in the laboratory environment. This work details the wind-free laboratory testing of some of the above-mentioned effects in order to develop a measurement interpretation algorithm capable of improving the accuracy of the Geonor T-200B vibrating wire gauge and the OTT Pluvio2 weighing gauge. Specifically, these experiments will examine the effects of temperature oscillations on the various gauge components, as well as snow capping and the potential heat-plume problem associated with heating the gauge orifices. These experiments use an artificial snow-generation machine: a snowflake simulation system in which snowflake sizes and snowfall rates can be controlled in a wind-free environment. The positive outcome of this preliminary phase would result in the transfer of the tested methodologies to the on-going WMO Solid Precipitation InterComparison Experiment (SPICE) campaign. The laboratory experiments are complemented by a preliminary analysis of the Marshall experimental site measurements (taken just outside of Boulder, Colorado, USA). The benefit achieved by applying the selected correction methodologies to real world observations will also be discussed.

Colli, Matteo; Landolt, Scott; Rasmussen, Roy; Govanni Lanza, Luca; La Barbera, Paolo

2013-04-01

406

A mechanism for preseismic steady rupture fronts observed in laboratory experiments  

NASA Astrophysics Data System (ADS)

It has been shown that the onset of frictional instability is characterized by a transition from stable, quasi-static rupture growth to unstable, inertially-controlled high-speed rupture. In particular, slow rupture fronts propagating at a steady speed Vslow of the order of 5% of the S-wave speed have been observed prior to the onset of dynamic rupture in recent fault-friction laboratory experiments. However, the precise mechanism governing this Vslow stage is unknown. Here we reproduce this phenomenon in numerical simulations of earthquake sequences that incorporate laboratory-derived rate-and-state friction laws. Our simulations show that the Vslow stage originates from a stress concentration inherited from the coalescence of interseismic slow creep fronts. Its occurrence is limited to a narrow range of the parameter space but is found in simulations with two commonly-used state-variable evolution laws in the rate-and-state formulation. The sensitivity of the speed Vslow to the model parameters suggests that the propagation speed Vslow reported in laboratory experiments may also be sensitive to parameters of friction and stress conditions. Our results imply that time and space dimensions associated with the propagation of Vslow on natural faults can be as much as a few seconds and several hundred meters, respectively. Hence the detection of such preseismic signals may be possible with near-field high-resolution observations.

Kaneko, Y.; Ampuero, J.-P.

2011-11-01

407

A mechanism for preseismic steady rupture fronts observed in laboratory experiments  

NASA Astrophysics Data System (ADS)

It has been shown that the onset of frictional instability is characterized by a transition from stable, quasi-static rupture growth to unstable, inertially-controlled high-speed rupture. In particular, slow `steady' fronts (which we call "V_slow") systematically propagating at ~5% of the S-wave speed prior to the onset of unstable rupture have been observed in recent fault-friction laboratory experiments (Nielsen et al., 2010). However, the precise mechanism of the occurrence of V_slow is unknown. Here we reproduce the occurrence of V_slow in numerical simulations of earthquake sequences that incorporate laboratory-derived rate-and-state friction laws. Our simulations show that the propagation of V_slow originates from a stress concentration inherited from the coalescence of interseismic slow creep fronts. The occurrence of V_slow is limited in a narrow range of the parameter space but is found in simulations with two commonly-used state-variable evolution laws in the rate-and-state formulation. Sensitivity of the speed of V_slow to the model parameters suggests that the previous laboratory experiments may have been carried out under special conditions. Our results imply that time and space dimensions associated with the propagation of V_slow on natural faults can be as much as a few seconds and several hundred meters, respectively. Hence the detection of such preseismic signals may be possible with near-field high-sampling GPS stations.

Kaneko, Y.; Ampuero, J. P.

2011-12-01

408

Zero-Gravity Atmospheric Cloud Physics Experiment Laboratory engineering concepts/design tradeoffs. Volume 1: Study results  

NASA Technical Reports Server (NTRS)

The work is summarized which was accomplished from January 1974 to October 1974 for the Zero-Gravity Atmospheric Cloud Physics Laboratory. The definition and development of an atmospheric cloud physics laboratory and the selection and delineation of candidate experiments that require the unique environment of zero gravity or near zero gravity are reported. The experiment program and the laboratory concept for a Spacelab payload to perform cloud microphysics research are defined. This multimission laboratory is planned to be available to the entire scientific community to utilize in furthering the basic understanding of cloud microphysical processes and phenomenon, thereby contributing to improved weather prediction and ultimately to provide beneficial weather control and modification.

Greco, R. V.; Eaton, L. R.; Wilkinson, H. C.

1974-01-01

409

Laboratory experiments designed to provide limits on the radionuclide source term for the NNWSI Project  

SciTech Connect

The Nevada Nuclear Waste Storage Investigations Project is investigating the suitability of the tuffaceous rocks at Yucca Mountain Nevada for potential use as a high-level nuclear waste repository. The horizon under investigation lies above the water table, and therefore offers a setting that differs substantially from other potential repository sites. The unsaturated zone environment allows a simple, but effective, waste package design. The source term for radionuclide release from the waste package will be based on laboratory experiments that determine the corrosion rates and mechanisms for the metal container and the dissolution rate of the waste form under expected long term conditions. This paper describes the present status of laboratory results and outlines the approach to be used in combining the data to develop a realistic source term for release of radionuclides from the waste package. 16 refs., 3 figs., 1 tab.

Oversby, V.M.; McCright, R.D.

1984-11-01

410

Colonization by aerobic bacteria in karst: Laboratory and in situ experiments  

USGS Publications Warehouse

Experiments were carried out to investigate the potential for bacterial colonization of different substrates in karst aquifers and the nature of the colonizing bacteria. Laboratory batch experiments were performed using limestone and PVC as substrates, a natural bacterial isolate and a known laboratory strain (Escherichia coli [E. coli]) as inocula, and karst ground water and a synthetic formula as growth media. In parallel, fragments of limestone and granite were submerged in boreholes penetrating two karst aquifers for more than one year; the boreholes are periodically contaminated by enteric bacteria from waste water. Once a month, rock samples were removed and the colonizing bacteria quantified and identified. The batch experiments demonstrated that the natural isolate and E. coli both readily colonized limestone surfaces using karst ground water as the growth medium. In contrast, bacterial colonization of both the limestone and granite substrates, when submerged in the karst, was less intense. More than 300 bacterial strains were isolated over the period sampled, but no temporal pattern in colonization was seen as far as strain, and colonization by E. coli was notably absent, although strains of Salmonella and Citrobacter were each observed once. Samples suspended in boreholes penetrating highly fractured zones were less densely colonized than those in the borehole penetrating a less fractured zone. The results suggest that contamination of karst aquifers by enteric bacteria is unlikely to be persistent. We hypothesize that this may be a result of the high flow velocities found in karst conduits, and of predation of colonizing bacteria by autochthonous zooplankton.

Personne, J.-C.; Poty, F.; Mahler, B.J.; Drogue, C.

2004-01-01

411

Energy supply and environmental issues: The Los Alamos National Laboratory experience in regional and international programs  

SciTech Connect

The Los Alamos National Laboratory, operated by the University of California, encompasses more than forty-three square miles of mesas and canyons in northern New Mexico. A Department of Energy national laboratory, Los Alamos is one of the largest multidisciplinary, multiprogram laboratories in the world. Our mission, to apply science and engineering capabilities to problems of national security, has expanded to include a broad array of programs. We conduct extensive research in energy, nuclear safeguards and security, biomedical science, computational science, environmental protection and cleanup, materials science, and other basic sciences. The Energy Technology Programs Office is responsible for overseeing and developing programs in three strategic areas: energy systems and the environment, transportation and infrastructure, and integrated chemicals and materials processing. Our programs focus on developing reliable, economic and environmentally sound technologies that can help ensure an adequate supply of energy for the nation. To meet these needs, we are involved in programs that range from new and enhanced oil recovery technologies and tapping renewable energy sources, through efforts in industrial processes, electric power systems, clean coal technologies, civilian radioactive waste, high temperature superconductivity, to studying the environmental effects of energy use.

Goff, S.J.

1995-12-31

412

Developing a theory of clinical instructor identity using the experiences of medical laboratory science practitioners.  

PubMed

This study investigated medical laboratory science clinical instructors' beliefs about teaching and how they viewed themselves as teachers. The first phase of the study included an integrative literature review, which suggested that the development of teacher identity in school-based educators, and to a lesser extent higher education faculty, is dependent on four dimensions: personal factors, training factors, contextual factors, and reflective practice. The second phase of this study began qualitative inquiry into the ways that these participants described their teaching and professional identity. Interviews were conducted with medical laboratory science clinical instructors in order to gain an understanding of their perceptions of themselves as teachers. The data collected in this study indicate that this group of clinical instructors saw themselves as teachers who were responsible for providing students with technical skills needed to become competent practitioners and the theoretical foundation necessary to pass the national certification exam. The study participants also saw themselves as mentors who were responsible for passing along professional knowledge to the next generation of laboratory practitioners. During data analysis three themes emerged that represent aspects of teacher identity in clinical instructors: belief in one's teaching ability, desire to expand one's professional responsibilities, and reflection on one's teaching. The findings from this study may provide a foundation for future research designed to measure teacher identity in clinical instructors. PMID:25000652

Miller, Wendy

2014-01-01

413

UV Radiation: a new first year physics/life sciences laboratory experiment  

NASA Astrophysics Data System (ADS)

Unfortunately, Australia leads the world in the number of skin cancer cases per capita. Three major factors that contribute to this are: 1) the level of damaging ultraviolet (UV) radiation in Australia is higher than in many other countries. This is caused, among other factors, by the stratospheric ozone depletion and Antarctic ozone hole; 2) many people in Australia are of Irish-Scottish origin and their skin can not repair the damage caused by the UV radiation as effectively as the skin of people of other origins; 3) Australia is one of the world’s leaders in the outdoor activities where people tend to spend more time outside. As our experience has shown, most Australian University students, high school students, and even high school teachers were largely unaware of the UV damage details and effective safety measures. Therefore, a need for new ways to educate people became apparent. The general aim of this new 1st year laboratory experiment, developed and first offered at La Trobe University (Melbourne, Australia) in 2009, is to investigate how UV-B radiation levels change under various solar illumination conditions and how effective different types of protection are. After pre-lab readings on physical concepts and biological effects of UV radiation, and after solving all pre-lab problems, the students go outside and measure the actual change in UV-B and UV-A radiation levels under various conditions. Some of these conditions are: direct sun, shade from a building, shade under the roof, reflection from various surfaces, direct sun through cheap and expensive sunglasses and eyeglasses, direct sun through various types of cloth and hair. The equipment used is the UV-Probe manufactured by sglux SolGel Technologies GmbH. The students’ feedback on this new laboratory experiment was very positive. It was ranked top among all physics experiments offered as part of that subject (Physics for Life Sciences) in 2009 and top among all physics experiments presented for peer evaluation at the Advanced Science Education Learning Laboratory Workshop in April 2010 at the University of Adelaide, Australia. All three main components of the UV Radiation experiment - pre-lab exercises, taking measurements, and a group discussion led by a demonstrator, were assessed by the students and by the teaching academics as a very important and valuable contribution to learning.

Petelina, S. V.; Siddaway, J. M.

2010-12-01

414

Gravity currents flowing upslope: Laboratory experiments and shallow-water simulations  

NASA Astrophysics Data System (ADS)

This paper investigates the dynamics of lock-release gravity currents propagating upslope by laboratory experiments and shallow-water simulations. Both the interface between the dense and the ambient fluid and the instantaneous velocity field were measured by image analysis. Different runs were carried out by varying the initial density of the lock fluid and the bed upslope. As a gravity current moves upslope, the dense layer becomes thinner, and an accumulation region of dense fluid in the initial part of the tank occurs. The current speed decreases as the bed upslope increases, and for the highest up sloping angles, the gravity current stops before reaching the end of the tank. A new two-layer shallow-water model is developed and benchmarked against laboratory experiments. The present model accounts for the mixing between the two layers, the free surface, and the space-time variations of the density. The effect of the horizontal density gradient in the simulation of gravity currents is investigated by comparing the numerical results of both the present model and the model proposed by Adduce et al. ["Gravity currents produced by lock-exchange: Experiments and simulations with a two layer shallow-water model with entrainment," J. Hydraul. Eng. 138, 111-121 (2012)] with laboratory measurements. The comparison shows that the present model reproduces both the current shape and the front position better than the Adduce et al. model, in particular, for gravity currents flowing up a slope. For these currents, the presence of a backflow near the lock is shown by the analysis of the streamwise depth-averaged velocity predicted by the present model and the velocity measured by particle image velocimetry as well.

Lombardi, V.; Adduce, C.; Sciortino, G.; La Rocca, M.

2015-01-01

415

Anisotropic viscosity and fabric evolution from laboratory experiments and field observations  

NASA Astrophysics Data System (ADS)

Crystallographic alignment of grains during solid-state deformation imparts anisotropic material properties to the bulk rock, which results in significant macroscopic anisotropy in viscosity. The majority of previous laboratory studies on geological materials have performed experiments on relatively untextured samples, making it difficult to quantify the magnitude of anisotropy. Here we present results of laboratory deformation experiments that first produce strong crystallographic fabrics and then test the viscosity of these textured aggregates in multiple stress states. Our results are used in a model for shear zone evolution to reproduce field measurements of strain variation across a natural shear zone. Two sets of deformation experiments were performed in a gas-medium apparatus at 1473 K and 300 MPa confining pressure. In the first set of experiments (Hansen et al., Nature, 2012), large-strain torsion imparts a fabric in which the dominant [100] orientation is parallel to the shear direction and the dominant [010] orientation is normal to the shear plane, typical of a fabric due to shear on the (010)[100] slip system. Subsequent tension parallel to the initial torsion axis occurs with most grains having unfavorable orientations for slip on available slip systems. In the second set of experiments, samples were initially deformed in tension and subsequently deformed in torsion, with the torsion axis parallel to the initial tensional load. Tension imparts a fabric in which the dominant [100] orientation is parallel to the tension direction, with girdles of [010] and [001] axes. Subsequent torsion occurs with some grains having favorable orientations for (100)[001] slip and other grains having unfavorable orientations for slip on available slip systems. Electron-backscatter diffraction maps of axial sections of samples reveal that the crystallographic fabric reorients into a more favorable orientation at a shear strain of ~1.5. In both sets of experiments the viscosities are ~1 order of magnitude larger in the unfavorable orientation than in the favorable orientation. The results of these experiments are used to model strain localization in a shear zone in the Josephine Peridotite (SW Oregon) in which crystallographic fabrics follow a similar evolution to that observed in our second set of experiments (Warren et al., EPSL, 2008). Synthetic strain profiles calculated using measured water contents, grain sizes, and laboratory-derived flow laws cannot reproduce the observed degree of strain localization. Viscous anisotropy is included in the calculation by incorporating a fabric tensor into laboratory-derived flow laws. The elements of this tensor are derived from the results of the deformation experiments. The rotation rate of the fabric anisotropy relative to the reference frame of the shear zone is defined using the crystallographic fabric evolution observed in the field. The degree of localization is more closely approximated when fabric evolution is taken into account, demonstrating that viscous anisotropy is an important component in the formation of lithospheric shear zones.

Hansen, Lars; Warren, Jessica; Zimmerman, Mark; Kohlstedt, David; Skemer, Philip; Hirth, Greg

2013-04-01

416

Estimated Uncertainties in the Idaho National Laboratory Matched-Index-of-Refraction Lower Plenum Experiment  

SciTech Connect

The purpose of the fluid dynamics experiments in the MIR (Matched-Index-of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for typical Very High Temperature Reactor (VHTR) plenum geometries in the limiting case of negligible buoyancy and constant fluid properties. The experiments use optical techniques, primarily particle image velocimetry (PIV) in the INL MIR flow system. The benefit of the MIR technique is that it permits optical measurements to determine flow characteristics in passages and around objects to be obtained without locating a disturbing transducer in the flow field and without distortion of the optical paths. The objective of the present report is to develop understanding of the magnitudes of experimental uncertainties in the results to be obtained in such experiments. Unheated MIR experiments are first steps when the geometry is complicated. One does not want to use a computational technique, which will not even handle constant properties properly. This report addresses the general background, requirements for benchmark databases, estimation of experimental uncertainties in mean velocities and turbulence quantities, the MIR experiment, PIV uncertainties, positioning uncertainties, and other contributing measurement uncertainties.

Donald M. McEligot; Hugh M. McIlroy, Jr.; Ryan C. Johnson

2007-11-01

417

Results from the EPL monkey-pod experiment conducted as part of the 1974 NASA/Ames shuttle CVT-2  

NASA Technical Reports Server (NTRS)

The participation of the Environmental Physiology Laboratory (EPL) in the general purpose laboratory concept verification test 3 is documented. The EPL Monkey-Pod Experiment was designed to incorporate a 10-12 kg, pig tailed monkey, Macaca nemestrina, into the pod and measure the physiological responses of the animal continuously. Four major elements comprise the EPL Monkey-Pod Experiment System: (1) a fiberglass pod containing the instrumented monkey plus feeder and watering devices, (2) an inner console containing the SKYLAB mass spectrometer with its associated valving and electronic controls, sensing, control and monitoring units for lower body negative pressure, feeder activity, waterer activity, temperatures, and gas metabolism calibration, (3) an umbilical complex comprising gas flow lines and electrical cabling between the inner and outer console and (4) an outer console in principle representing the experiment support to be provided from general spacecraft sources.

Rahlmann, D. F.; Kodama, A. M.; Mains, R. C.; Pace, N.

1974-01-01

418

Results from the EPL monkey-pod flight experiments conducted aboard the NASA/Ames CV-990, May 1976  

NASA Technical Reports Server (NTRS)

The participation of the Environmental Physiology Laboratory (EPL) in the general purpose laboratory concept verification test 3 is documented. The EPL Monkey-Pod Experiment was designed to incorporate a 10-12 kg, pig tailed monkey, Macaca nemestrina, into the pod and measure the physiological responses of the animal continously. Four major elements comprise the EPL Monkey-Pod Experiment System: (1) a fiberglass pod containing the instrumented monkey plus feeder and watering devices, (2) an inner console containing the SKYLAB mass spectrometer with its associated valving and electronic controls, sensing, control and monitoring units for lower body negative pressure, feeder activity, waterer activity, temperatures, and gas metabolism calibration, (3) an umbilical complex comprising gas flow lines and electrical cabling between the inner and outer console and (4) an outer console in principle representing the experiment support to be provided from general space craft sources.

Rahlmann, D. F.; Kodama, A. M.; Mains, R. C.; Pace, N.

1976-01-01

419

Creating an infrastructure for training in the responsible conduct of research: the University of Pittsburgh's experience.  

PubMed

In response to public concerns about the consequences of research misconduct, academic institutions have become increasingly cognizant of the need to implement comprehensive, effective training in the responsible conduct of research (RCR) for faculty, staff, students, and external collaborators. The ability to meet this imperative is challenging as universities confront declining financial resources and increasing complexity of the research enterprise. The authors describe the University of Pittsburgh's design, implementation, and evaluation of a Web-based, institution-wide RCR training program called Research and Practice Fundamentals (RPF). This project, established in 2000, was embedded in the philosophy, organizational structure, and technology developed through the Integrated Advanced Information Management Systems grant from the National Library of Medicine. Utilizing a centralized, comprehensive approach, the RPF system provides an efficient mechanism for deploying content to a large, diverse cohort of learners and supports the needs of research administrators by providing access to information about who has successfully completed the training. During its first 3 years of operation, the RPF served over 17,000 users and issued more than 38,000 training certificates. The 18 modules that are currently available address issues required by regulatory mandates and other content areas important to the research community. RPF users report high levels of satisfaction with content and ease of using the system. Future efforts must explore methods to integrate non-RCR education and training into a centralized, cohesive structure. The University of Pittsburgh's experience with the RPF demonstrates the importance of developing an infrastructure for training that is comprehensive, scalable, reliable, centralized, affordable, and sustainable. PMID:16436572

Barnes, Barbara E; Friedman, Charles P; Rosenberg, Jerome L; Russell, Joanne; Beedle, Ari; Levine, Arthur S

2006-02-01

420

Laboratory performance of the BEAR (Beam Experiment Aboard Rocket) RFQ (radio-frequency quadrupole)  

SciTech Connect

The BEAR (Beam Experiment Aboard Rocket) accelerator will be part of an experiment to demonstrate the operation of an ion accelerator in space and to characterize the exoatmospheric propagation of a neutral particle beam. The RFQ (radio-frequency quadrupole) has been designed to produce a 25-mA H/sup /minus// beam with an emittance of 0.01 cm-mrad (rms normalized) at an energy of 1 MeV. Because of the rigors of spaceflight, the accelerator design has been constrained by factors not normally applicable to conventional terrestrial accelerators. These factors and the mechanical features are described in a companion paper in these proceedings. The design techniques developed for BEAR would be applicable whenever, rugged, lightweight, or power-efficient systems are required. The BEAR RFQ has been operated under power with beam in the laboratory. This paper details of measured beam transport, emittance, and energy spectra. 6 refs., 4 figs.

O'Shea, P.G.; Schrage, D.L.; Young, L.M.; Zaugg, T.J.; Lynch, M.T.; McKenna, K.F.; Hansborough, L.D.

1988-01-01

421

Effects of organic enrichment on sandy beach meiofauna: A laboratory microcosm experiment  

NASA Astrophysics Data System (ADS)

Meiofauna samples from intertidal sediments of Qingdao No.2 Bathing Beach, China, were collected for field study, and subjected to organic enrichment in a laboratory microcosm experiment for 21 d. There were three different treatments including non-organic addition as the control, low-organic enrichment (2 g DW green algae per 150 mL) and high-organic enrichment (10 g DW green algae per 150 mL). After 21 d, the meiofauna richness decreased in both organic enrichment treatments. Among the three treatments, total meiofauna abundance was significantly different, and the control groups had higher abundance than the other two treatment groups. However, the responses of the meiofauna abundance in the two organic enrichment treatments were non-significantly different. The relationship of meiofaunal abundance and nematode/copepod ratios to organic matter and oxygen level in the microcosm experiments were discussed.

Wang, Jianing; Zhou, Hong; Zhang, Zhinan; Cong, Bingqing; Xu, Shuhui

2011-09-01

422

Limits on WIMP cross-sections from the NAIAD experiment at the Boulby Underground Laboratory  

E-print Network

The NAIAD experiment (NaI Advanced Detector) for WIMP dark matter searches at the Boulby Underground Laboratory (North Yorkshire, UK) ran from 2000 until 2003. A total of 44.9 kg x years of data collected with 2 encapsulated and 4 unencapsulated NaI(Tl) crystals with high light yield were included in the analysis. We present final results of this analysis carried out using pulse shape discrimination. No signal associated with nuclear recoils from WIMP interactions was observed in any run with any crystal. This allowed us to set upper limits on the WIMP-nucleon spin-independent and WIMP-proton spin-dependent cross-sections. The NAIAD experiment has so far imposed the most stringent constraints on the spin-dependent WIMP-proton cross-section.

The UK Dark Matter Collaboration

2005-04-17

423

Sediment trapping efficiency of adjustable check dam in laboratory and field experiment  

NASA Astrophysics Data System (ADS)

Check dam has been constructed at mountain area to block debris flow, but has been filled after several events and lose its function of trapping. For the reason, the main facilities of our research is the adjustable steel slit check dam, which with the advantages of fast building, easy to remove or adjust it function. When we can remove transverse beams to drain sediments off and keep the channel continuity. We constructed adjustable steel slit check dam on the Landow torrent, Huisun Experiment Forest station as the prototype to compare with model in laboratory. In laboratory experiments, the Froude number similarity was used to design the dam model. The main comparisons focused on types of sediment trapping and removing, sediment discharge, and trapping rate of slit check dam. In different types of removing transverse beam showed different kind of sediment removal and differences on rate of sediment removing, removing rate, and particle size distribution. The sediment discharge in check dam with beams is about 40%~80% of check dam without beams. Furthermore, the spacing of beams is considerable factor to the sediment discharge. In field experiment, this research uses time-lapse photography to record the adjustable steel slit check dam on the Landow torrent. The typhoon Soulik made rainfall amounts of 600 mm in eight hours and induced debris flow in Landow torrent. Image data of time-lapse photography demonstrated that after several sediment transport event the adjustable steel slit check dam was buried by debris flow. The result of lab and field experiments: (1)Adjustable check dam could trap boulders and stop woody debris flow and flush out fine sediment to supply the need of downstream river. (2)The efficiency of sediment trapping in adjustable check dam with transverse beams was significantly improved. (3)The check dam without transverse beams can remove the sediment and keep the ecosystem continuity.

Wang, Chiang; Chen, Su-Chin; Lu, Sheng-Jui

2014-05-01

424

AC 2011-75: ENHANCING STUDENT LEARNING THROUGH HANDS-ON LABORATORY EXPERIMENTS ON RENEWABLE ENERGY SOURCES  

E-print Network

mathematics or physics background. Each laboratory experiment introduced a miniature version of an energy and at the end of the academic term. Each questionnaire consisted of five different types of questions relevant on performance improvements by laboratory type, class level, gender and student major. In more detail, our

425

LabView™ Based Nuclear Physics Laboratory experiments as a remote teaching and training tool for Latin American Educational Centers  

NASA Astrophysics Data System (ADS)

A virtual laboratory via internet to provide a highly iterative and powerful teaching tool for scientific and technical discipline is given. The experimenter takes advantage of a virtual laboratory and he can execute nuclear experiment at introductory level e.g. Gamma ray detection with Geiger-Müller Counter at remote location using internet communication technology.

Sajo-Bohus, L.; Greaves, E. D.; Barros, H.; Gonzalez, W.; Rangel, A.

2007-10-01

426

Lighting up Protons with MorphFl, a Fluorescein-Morpholine Dyad: An Experiment for the Organic Laboratory  

ERIC Educational Resources Information Center

A two-period organic laboratory experiment that includes fluorescence sensing is presented. The pH-sensitive sensor MorphFl is prepared using a Mannich reaction between a fluorescein derivative and the iminium ion of morpholine. During the first laboratory, students prepare MorphFl. The second session begins with characterizing the sensor using…

Miller, Tyson A.; Spangler, Michael; Burdette, Shawn C.

2011-01-01

427

LabView Based Nuclear Physics Laboratory experiments as a remote teaching and training tool for Latin American Educational Centers  

SciTech Connect

A virtual laboratory via internet to provide a highly iterative and powerful teaching tool for scientific and technical discipline is given. The experimenter takes advantage of a virtual laboratory and he can execute nuclear experiment at introductory level e.g. Gamma ray detection with Geiger-Mueller Counter at remote location using internet communication technology.

Sajo-Bohus, L.; Greaves, E. D.; Barros, H.; Gonzalez, W. [Universidad Simon Bolivar, Apartado 89000, Caracas 1080A (Venezuela); Rangel, A. [Universidad del Zulia Maracaibo (Venezuela)

2007-10-26

428

Virtual laboratory: assessment of a b-learning experience for teaching Physics in Engineering  

NASA Astrophysics Data System (ADS)

During the autumn semester of 2008/09 term, we have carried out an experience of teaching an innovative subject at our University. The subject is open and elective for all the students at the University, most of them in Engineering degrees. We call it "Physics virtual laboratory ". The students use a CMS (course management system) for accessing the syllabus, and the materials for the course. These materials include videos, sound and rich text for describing some well known experiments in a Physics lab. They also have a test for each unit and have to submit a written essay for every experiment at a fixed date. They work with the help of the teacher that answer their questions and provide solutions for the exercises, so this course is not entirely e-learning, but rather blended learning. For every unit, we have prepared materials that serve as a guide for the experiment, without being physically at the laboratory and without measuring any physical quantities. All the necessary data are given, and the real apparatus are shown in videos embedded in the document and described in detail. The experiments chosen cover those found in a typical Physics lab: kinematics in an air-cushion rail, Boyle-Mariotte law, magnetic field inside a solenoid, simple circuits, lenses… The number is limited to seven experiments for time constraint reasons. In a given experiment, we put emphasis in quantifying the uncertainty of the results, and several ways of calculating it are explained in detail using Excel spreadsheets. After the subject has ended, we have gathered feedback from the students, and have taken note of how they rate it compared with more traditional subjects. Also, we assess our work and the usefulness of the materials and the fitness of the structure of the subject. This is important for assuring that the change in methodology is better for the learing process. In this communication we present the results of this assessment and try to reach some conclusions that might be useful in many engineering subjects that use b-learning methodologies.

Ablanque, J.; Seidel, L.; Losada, J. C.

2009-04-01

429

Electropolymerized Conducting Polymers as Glucose Sensors  

Microsoft Academic Search

Conducting polymers are of considerable interest. Their electrochemical synthesis requires only inexpensive starting materials and low-cost equipment. This paper presents a laboratory-based experiment for possible inclusion in the undergraduate instrumental analysis laboratory curriculum. The objectives are to perform cyclic voltammetry on electropolymerized conducting polymers, to observe the effects of various parameters on the voltammogram obtained, and to perform quantitative analysis

Omowunmi A. Sadik; Sharin Brenda; Patrick Joasil; John Lord

1999-01-01

430

Using laboratory experiments to improve reliability in rainfall and solid precipitation weighing-gauge measurements  

NASA Astrophysics Data System (ADS)

Snowfall, drizzle and light rainfall events (defined as events with intensities < 12 mm/h) can often be hard to detect over a short-time resolution due to sampling limitations, wind effects, and noise influencing the weighing-gauge measurements. In many instances, the noise observed in the data sampling can often be greater than the detectable signal from a real precipitation event. Wind can be one of the largest contributors to gauge undercatch, and can also increase noise due to wind pumping on the measurement devices inside the gauges. Various algorithms have been devised to help reduce noise and other unwanted effects in precipitation gauge measurements. Most of these algorithms have focused on the removal of wind effects, while others have focused on reducing temperature dependencies and snow capping. Recent laboratory testing has demonstrated the ability to reproduce some of these anomalies observed in precipitation measurements during field trial campaigns. Assessing the factors contributing to these anomalies is required to accurately simulate these conditions in the laboratory. It is also important to understand these factors to support the selection of the appropriate natural conditions to be simulated in the laboratory environment. Significant research has already been undertaken to measure the influence of wind affecting the gauges. This work details the wind-free laboratory testing of some of the above-mentioned algorithms developed to improve measurement accuracy from the Geonor T-200b vibrating wire gauge and the OTT Pluvio2 weighing gauges. Specifically, these experiments will examine the effects of temperature oscillations and their subsequent effects on the various gauge components, as well as snow capping and the potential heat-plume problem associated with heating the gauges. These experiments employ an artificial snow-generation machine; a snowflake simulation system in which snowflake sizes and snowfall rates can be controlled in a wind-free environment. The positive outcome of this preliminary phase would result in the transfer of the tested methodologies to the upcoming WMO Solid Precipitation InterComparison Experiment (SPICE) campaign, beginning winter 2012 at different sites located in various participant countries.

Landolt, S.; Colli, M.; La Barbera, P.; Lanza, L. G.; Rasmussen, R.

2012-12-01

431

NIF Laboratory Astrophysics Experiments Investigating The Effects Of A Radiative Shock On Hydrodynamic Instabilities  

NASA Astrophysics Data System (ADS)

This paper will describe ongoing laboratory astrophysics experiments at the National Ignition Facility (NIF) relevant to the complex radiation hydrodynamics that occurs in red supergiant, and core-collapse supernovae. Experiments on NIF can deliver 300 eV radiative heating that can be utilized uniquely access the regime in which radiation affects the development of hydrodynamic instabilities within an evolving object. This is relevant to the dynamics that occur during the core-collapse explosions of red supergiant stars. These stars have dense circumstellar plasma, producing a strongly radiative shock whose radiation interacts with the hydrodynamic structures produced by instabilities during the explosion. While published astrophysical simulations have not included complex, multidimensional radiation hydrodynamics, such effects are very physical and expected to affect the evolution of early stages of astrophycal objects described above. This presentation will include a summary of the two test shots that we have performed on NIF, including a 0.7 scale, gas-filled hohlraum test shot, and a description of the integrated physics shots scheduled at the facility. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas under grant number DE-FG52-09NA29548 , the Lawrence Livermore National Security, LLC, under Contract No. DE-AC52-07NA27344 and Predictive Sciences Academic Alliances Program in NNSA-ASC via grant DEFC52- 08NA28616.

Kuranz, Carolyn; Drake, R. P.; Park, H. S.; Remington, B. A.; Huntington, C. M.; Doss, F. W.; Krauland, C. M.; Harding, E. C.; Grosskopf, M. J.; Marion, D. C.; Myra, E.; Fryxell, B.; Kalantar, D. H.; Keane, C. J.; Kilkenny, J. D.; Robey, H. F.; Maddox, B. R.; Miles, A. R.; Wallace, R. J.; May, M. J.; Kline, J. L.; Kyrala, G. A.; Plewa, T.; Wheeler, J. C.; Arnett, W. D.; Giraldez, E.; Nikroo, A.

2010-05-01

432

NIF Laboratory Astrophysics Experiments Investigating The Effects Of A Radiative Shock On Hydrodynamic Instabilities  

NASA Astrophysics Data System (ADS)

This paper will describe ongoing laboratory astrophysics experiments at the National Ignition Facility (NIF) relevant to the complex radiation hydrodynamics that occurs in red supergiant, and core-collapse supernovae. Experiments on NIF can deliver 300 eV radiative heating that can be utilized uniquely access the regime in which radiation affects the development of hydrodynamic instabilities within an evolving object. This is relevant to the dynamics that occur during the core-collapse explosions of red supergiant stars. These stars have dense circumstellar plasma, producing a strongly radiative shock whose radiation interacts with the hydrodynamic structures produced by instabilities during the explosion. While published astrophysical simulations have not included complex, multidimensional radiation hydrodynamics, such effects are very physical and expected to affect the evolution of early stages of astrophysical objects described above. This presentation will include a summary of the two test shots that we have performed on NIF, including a 0.7 scale, gas-filled hohlraum test shot, and a description of the integrated physics shots scheduled at the facility. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas under grant number DE-FG52-09NA29548 , the Lawrence Livermore National Security, LLC, under Contract No. DE-AC52-07NA27344 and Predictive Sciences Academic Alliances Program in NNSA-ASC via grant DEFC52- 08NA28616.

Kuranz, Carolyn C.; Drake, R. P.; Huntington, C. M.; Klein, S. R.; Trantham, M. R.; Park, H. S.; Remington, B. A.; Miles, A. R.; Raman, K.; Kline, J. L.; Plewa, T.

2012-05-01

433

Los Alamos National Laboratory: A guide to records series supporting epidemiologic studies conducted for the Department of Energy  

SciTech Connect

The purpose of this guide is to describe each series of records that pertains to the epidemiologic studies conducted by the Epidemiology Section of the Occupational Medicine Group (ESH-2) at the Department of Energy`s (DOE) Los Alamos National Laboratory (LANL) in Los Alamos, New Mexico. The records described in this guide relate to occupational studies performed by the Epidemiology Section, including those pertaining to workers at LANL, Mound Plant, Oak Ridge Reservation, Pantex Plant, Rocky Flats Plant, and Savannah River Site. Also included are descriptions of other health-related records generated or collected by the Epidemiology Section and a small set of records collected by the Industrial Hygiene and Safety Group. This guide is not designed to describe the universe of records generated by LANL which may be used for epidemiologic studies of the LANL work force. History Associates Incorporated (HAI) prepared this guide as part of its work as the support services contractor for DOE`s Epidemiologic Records Inventory Project. This introduction briefly describes the Epidemiologic Records Inventory Project, HAI`s role in the project, the history of LANL the history and functions of LANL`s Health Division and Epidemiology Section, and the various epidemiologic studies performed by the Epidemiology Section. It provides information on the methodology that HAI used to inventory and describe records housed in the offices of the LANL Epidemiology Section in Technical Area 59 and at the LANL Records Center. Other topics include the methodology used to produce the guide, the arrangement of the detailed record series descriptions, and information concerning access to records repositories.

NONE

1997-01-01

434

Students' Design of Experiments: An Inquiry Module on the Conduction of Heat  

ERIC Educational Resources Information Center

This article examines secondary students' design of experiments after engagement in an innovative and inquiry-oriented module on heat transfer. The module consists of an integration of hands-on experiments, simulated experiments and microscopic model simulations, includes a structured series of guided investigative tasks and was implemented for a…

Hatzikraniotis, E.; Kallery, M.; Molohidis, A.; Psillos, D.

2010-01-01

435

Solifluction Processes in Arctic Permafrost: Results of Laboratory and Field Experiments  

NASA Astrophysics Data System (ADS)

Two experiments designed to measure solifluction processes associated with two-sided active layer freezing (from the surface down and from the permafrost table up) are reported. Firstly, a slope model, constructed within a 5 m square refrigerated container at the CNRS laboratories in Caen, France was subjected to repeated cycles of freezing and thawing. The slope, of thickness 35 cm and gradient 12°, was constructed using natural aeolian silt. A refrigerated plate maintained a permafrost table at the base of the soil. Air temperatures were between -8°C and -12°C during freezing cycles, and between +8°C and +16°C during thaw, allowing the effects of changing geothermal regime to be explored. Data were collected from thermistors, Druck PDCR 81 miniature pore pressure transducers and from a pair of LVDTs mounted on a beam and connected to a footplate embedded in the soil surface. LVDTs allowed continuous monitoring of frost heave, thaw settlement and down slope soil movements. A similar array of sensors was installed on a 7° slope in Svalbard in August 2005 to provide long-term monitoring of active-layer processes, and allow field validation of the laboratory experiment. LVDTs were mounted on a tubular steel frame, with legs firmly frozen into the permafrost. Drilling revealed an ice-rich transition zone at the active-layer permafrost interface. Results are presented from laboratory and field illustrating frost heave and thaw settlement, ice segregation during winter and summer, pore water pressure variations during soil freezing and thawing, and the rates and timing of solifluction movements. Finally, the potential effects of climate change on solifluction rates at the high arctic permafrost field site are contrasted with likely effects in lower latitude non-permafrost areas with seasonal ground freezing.

Harris, C.; Luetschg, M. A.; Murton, J. B.; Smith, F. W.; Davies, M. C.; Christiansen, H. H.; Ertlen-Font, M.

2006-12-01

436

The awareness of novelty for strangely familiar words: a laboratory analogue of the déjà vu experience.  

PubMed

Déjà vu is a nebulous memory experience defined by a clash between evaluations of familiarity and novelty for the same stimulus. We sought to generate it in the laboratory by pairing a DRM recognition task, which generates erroneous familiarity for critical words, with a monitoring task by which participants realise that some of these erroneously familiar words are in fact novel. We tested 30 participants in an experiment in which we varied both participant awareness of stimulus novelty and erroneous familiarity strength. We found that déjà vu reports were most frequent for high novelty critical words (?25%), with low novelty critical words yielding only baseline levels of déjà vu report frequency (?10%). There was no significant variation in déjà vu report frequency according to familiarity strength. Discursive accounts of the experimentally-generated déjà vu experience suggest that aspects of the naturalistic déjà vu experience were captured by this analogue, but that the analogue was also limited in its focus and prone to influence by demand characteristics. We discuss theoretical and methodological considerations relevant to further development of this procedure and propose that verifiable novelty is an important component of both naturalistic and experimental analogues of déjà vu. PMID:25401055

Urquhart, Josephine A; O'Connor, Akira R

2014-01-01

437

The awareness of novelty for strangely familiar words: a laboratory analogue of the déjà vu experience  

PubMed Central

Déjà vu is a nebulous memory experience defined by a clash between evaluations of familiarity and novelty for the same stimulus. We sought to generate it in the laboratory by pairing a DRM recognition task, which generates erroneous familiarity for critical words, with a monitoring task by which participants realise that some of these erroneously familiar words are in fact novel. We tested 30 participants in an experiment in which we varied both participant awareness of stimulus novelty and erroneous familiarity strength. We found that déjà vu reports were most frequent for high novelty critical words (?25%), with low novelty critical words yielding only baseline levels of déjà vu report frequency (?10%). There was no significant variation in déjà vu report frequency according to familiarity strength. Discursive accounts of the experimentally-generated déjà vu experience suggest that aspects of the naturalistic déjà vu experience were captured by this analogue, but that the analogue was also limited in its focus and prone to influence by demand characteristics. We discuss theoretical and methodological considerations relevant to further development of this procedure and propose that verifiable novelty is an important component of both naturalistic and experimental analogues of déjà vu. PMID:25401055

Urquhart, Josephine A.

2014-01-01

438

Stability of quasi-Keplerian Shear Flow in a Laboratory Experiment  

SciTech Connect

Subcritical transition to turbulence has been proposed as a source of turbulent viscosity required for the associated angular momentum transport for fast accretion in Keplerian disks. Previously cited laboratory experiments in supporting this hypothesis were performed either in a di erent type of flow than Keplerian or without quantitative measurements of angular momentum transport and mean flow profile, and all of them appear to su er from Ekman e ects, secondary flows induced by nonoptimal axial boundary conditions. Such Ekman e ects are expected to be absent from astronomical disks, which probably have stress-free vertical boundaries unless strongly magnetized. Aims. To quantify angular momentum transport due to subcritical hydrodynamic turbulence, if exists, in a quasi-Keplerian flow with minimized Ekman e ects. Methods.We perform a local measurement of the azimuthal-radial component of the Reynolds stress tensor in a novel laboratory apparatus where Ekman e ects are minimized by flexible control of axial boundary conditions. Results.We find significant Ekman e ects on angular momentum transport due to nonoptimal axial boundary conditions in quasi-Keplerian flows. With the optimal control of Ekman e ects, no statistically meaningful angular momentum transport is detected in such flows at Reynolds number up to two millions. Conclusions. Either a subcritical transition does not occur, or, if a subcritical transition does occur, the associated radial transport of angular momentum in optimized quasi-Keplerian laboratory flows is too small to directly support the hypothesis that subcritical hydrodynamic turbulence is responsible for accretion in astrophysical disks. Possible limitations in applying laboratory results to astrophysical disks due to experimental geometry are discussed.

Ethan Schartman, Hantao Ji, Michael J. Burin and Jeremy Goodman

2012-06-19

439

Conducting research using the emergency exception from informed consent: the Public Access Defibrillation (PAD) Trial experience  

Microsoft Academic Search

Background: The Public Access Defibrillation (PAD) Trial, a prospective, multicenter, randomized clinical trial comparing two prehospital resuscitation strategies, was conducted under the regulations for exception from informed consent (21CFR50.24) in 24 communities in North America. These regulations place additional requirements for human subject protection on investigators and Institutional Review Boards (IRBs), including conducting community consultation (CC) and public disclosure (PD).

Vincent N Mosesso; Lawrence H Brown; H. Leon Greene; Terri A Schmidt; Tom P Aufderheide; Michael R Sayre; Shannon W Stephens; Andrew Travers; Richard A Craven; Myron L Weisfeldt

2004-01-01

440

Gas release during salt well pumping: model predictions and comparisons to laboratory experiments  

SciTech Connect

The Hanford Site has 149 single-shell tanks (SSTs) containing radioactive wastes that are complex mixes of radioactive and chemical products. Some of these wastes are known to generate mixtures of flammable gases, including hydrogen, nitrous oxide, and ammonia. Nineteen of these SSTs have been placed on the Flammable Gas Watch List (FGWL) because they are known or suspected, in all but one case, to retain these flammable gases. Salt well pumping to remove the interstitial liquid from SSTs is expected to cause the release of much of the retained gas, posing a number of safety concerns. Research at the Pacific Northwest National Laboratory (PNNL) has sought to quantify the release of flammable gases during salt well pumping operations. This study is being conducted for Westinghouse Hanford Company as part of the PNNL Flammable Gas Project. Understanding and quantifying the physical mechanisms and waste properties that govern gas release during salt well pumping will help to resolve the associated safety issues.

Peurrung, L.M.; Caley, S.M.; Bian, E.Y.; Gauglitz, P.A.

1996-09-01

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