Note: This page contains sample records for the topic laboratory experiments conducted from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

An undergraduate laboratory experiment on quantized conductance in nanocontacts  

NSDL National Science Digital Library

An article published in 1999 by the American Journal of Physics that describes an experiment on quantum conductance of nanocontacts. This material is an important reference for modern versions of the experiment.

2011-06-11

2

Measurement of conductivity in metals: a simple laboratory experiment on induced currents  

NASA Astrophysics Data System (ADS)

An accurate laboratory experiment for contactless measurement of resistivity in nonferromagnetic conductive tubes has been developed. The experimental setup corresponds to an electrical transformer, the tube being the core. Study of the magnetic screening caused by the currents induced in the tube allows its conductivity to be determined with a precision better than 1%.

Iñiguez, J.; Raposo, V.

2007-11-01

3

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

4

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

ERIC Educational Resources Information Center

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

Kravchuk, Olena; Elliott, Antony; Bhandari, Bhesh

2005-01-01

5

Laboratory Determination of Hydraulic Conductivity  

NSDL National Science Digital Library

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

2008-02-07

6

Determination of the thermal conductivity of opalinus clay via simulations of experiments performed at the Mont Terri underground laboratory  

NASA Astrophysics Data System (ADS)

Storage in deep geological formations is a potential solution for the management of high-level radioactive wastes. In this context, different types of rocks such as argillite are extensively studied. In the Mont Terri underground laboratory (Switzerland), several experiments have been performed in order to characterize the properties of the opalinus clay. One of these experiments, called HE-C, has consisted in measuring in situ the time evolution of the rock temperature submitted to a heating source. Experimental measurements have shown that the thermal behaviour of the clay was not homogeneous around the borehole where the heater was installed. Furthermore, 3D direct numerical simulations of this experiment performed with the code Cast3M have proved that it was necessary to introduce a new parameter ? to model the amount of electric power lost in cables and by air convection inside the metallic tube containing the heater. A numerical simulation optimization technique has been used to estimate the thermal longitudinal and transverse conductivities (?// and ??) of the host rock. It consists in minimizing an objective function that is the sum of the squared differences between measured and calculated temperatures. But this method induced a lot of Cast3M simulations. In order to drastically reduce the CPU time, we used a neural network approximation built from a sample training of 1100 Cast3M simulations. It allowed us to calculate the objective function for 500 000 different values of the triplet (?//,??,?). Finally, we obtained the following values for the thermal conductivitieson one side of the borehole, ?// = 1.84 ± 0.04 W m- 1 K- 1 and ?? = 0.55 ± 0.03 W m- 1 K- 1;on the other side, ?// = 1.90 ± 0.07 W m- 1 K- 1 and ?? = 1.07 ± 0.09 W m- 1 K- 1. The estimated thermal conductivities ?? perpendicular to the bedding plane are quite different. It is perhaps caused by the presence of an intensive fractured zone on one side of the borehole, due to bentonite swelling. It can also be due to the presence of a bed of carbonated rock.

Mügler, C.; Filippi, M.; Montarnal, Ph.; Martinez, J.-M.; Wileveau, Y.

2006-02-01

7

An Organoleptic Laboratory Experiment  

Microsoft Academic Search

Flavorings in foods and fragrances in personal care products is a topic often discussed in chemistry classes designed for the general education of non-science majors. A laboratory experiment has been designed to accompany the lecture topic. Compounds in ten different classes of organic molecules that are used in the fragrance and food industry are provided to students. Students whiff the

John M. Risley

1996-01-01

8

Laboratory techniques to evaluate thermal conductivity for some soils  

Microsoft Academic Search

The thermal conductivity of two soils was investigated through laboratory studies. These laboratory experiments used the single probe and dual probe methods to measure and compare thermal conductivities. The soils used were classified as sand and loam. Thermal conductivity measured using single probe method ranged from 0.95 to 2.11 for sand and from 0.49 to 0.76 W\\/m K for loam.

O. K. Nusier; N. H. Abu-Hamdeh

2003-01-01

9

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

10

REACTOR LABORATORY EXPERIMENTS  

Microsoft Academic Search

An exposition is presented comprising a basic set of experiments in ; reactor physics, engineering, and technology developed by the International ; Institute of Nuclear Science and Engineering. Twenty-two experiments are ; included in a program which may be divided into groups associated with the ; Argonaut Reactor, the AGN-201 Reactor, and with other reactors or auxiliary ; equipment. (J.R.D.);

Sturm; W. J. ed

1961-01-01

11

Laboratory Dynamo Experiments  

NASA Astrophysics Data System (ADS)

The basic physics of a dynamo have been addressed utilizing magnetohydrodynamic (MHD) simulations and liquid metal experiments to determine the requirements for the excitation, sustainment, and saturation of magnetic fields generated from turbulent flows. The more challenging problem of addressing plasma physics effects will require experiments with unmagnetized plasmas. An experimental facility utilizing cusp field confinement to produce a hot, steadystate unmagnetized plasma would provide the necessary conditions for studying effects beyond MHD (such as two-fluid and kinetic effects) in a turbulent dynamo.

Nornberg, M. D.; Forest, C. B.; Brown, B. P.; Zweibel, E. G.; Wallace, J. B.; Clark, M.; Spence, E. J.; Taylor, N. Z.; Kaplan, E. J.; Rahbarnia, K.

2011-05-01

12

Laboratory magnetic reconnection experiments  

NASA Astrophysics Data System (ADS)

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

Ono, Yasushi

13

Cultural Goods and Laboratory Experiments  

Microsoft Academic Search

In a two-stage public goods experiment, we study the framing effect due to the adoption of a cultural context. Our results show a slight increase in the allocations of subjects’ endowments to the cultural good when the cultural context is implemented in the laboratory. In particular, in one treatment, the framing effect has a strong impact in the last two

Massimo Finocchiaro Castro

2005-01-01

14

Laboratory Experiments on Magnetic Reconnection  

NASA Astrophysics Data System (ADS)

Magnetic reconnection, a topological rearrangement of magnetic field lines, is one of the key self-organization processes in laboratory and astrophysical plasmas. This talk presents the fundamental physics of magnetic reconnection reviewing the recent significant progress in laboratory experiments. Sawtooth relaxation in a tokamak plasma, which represents a repetitive change of the electron temperature profile, provides a good example of magnetic reconnection. During the relaxation phase of the sawtooth, a rapid flattening of the electron temperature profile occurs and the pitch of field lines changes suddenly as the field lines break and rearrange themselves to form a new topological profile. In the reversed field pinch (RFP) and spheromak plasmas, a sudden re-arrangement of field lines in an inner flux surface can trigger another rearrangement in the outer flux surfaces, leading to a global magnetic relaxation event. Magnetic reconnection physics has been investigated in a variety of laboratory experiments dedicated for reconnection research. These laboratory experiments have made important contributions to recent advances in our understanding of magnetic reconnection. Significant findings are as follows: 1) The reconnection dynamics are determined both by local and global conditions, 2) The profiles of the reconnection layer and reconnection rate change drastically as the plasma's collisionality is reduced, 3) Two-fluid dynamics have been verified through experimental identification of both the ion and electron diffusion layers, 4) Electrostatic and electromagnetic fluctuations and their spatial profiles were measured in the reconnection layer of both laboratory and space plasmas with notable similarities, and 5) The reconnection rate increases significantly when the ratio of the electron mean free path to the scale length approaches unity. A new scaling of reconnection resistivity with respect to this ratio has been obtained from the laboratory results. The impact of this recently advanced understanding on research on space-terrestrial plasmas will be discussed.

Yamada, Masaaki

2010-05-01

15

Culture experiments on conductive polymers  

NASA Astrophysics Data System (ADS)

Fibroblast L929 and myoblast C2C12 cells of the mouse connective tissue origin were sown on the surface of conductive polymer films (polypyrrole, PPy and poly(3,4-ethylenedioxythiophene), PEDOT) in the cell culture medium, and the proliferative process of these cells was observed. Without changing the form, fibroblast L929 and myoblast C2C12 cells were observed to proliferate almost similarly to the cell which cultured on a dish on the market and to maintain compatibility. In other word, it has been understood these two kinds of conductive polymers used in this study, the PEDOT films maintain the secretion function of the cell cultured on the surface of these polymers. Therefore, the PPy- and the PEDOT-coated electrode suggested the possibility usable as a nerve stimulation electrode with biocompatibility, because these polymers were effective to culture the cell.

Onoda, Mitsuyoshi

2012-04-01

16

Laboratory Electrical Conductivity Measurement of Mantle Minerals  

Microsoft Academic Search

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

Takashi Yoshino

2010-01-01

17

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

EPA Science Inventory

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

18

Laboratory astrophysical collisionless shock experiments  

NASA Astrophysics Data System (ADS)

Astrophysical ``collisionless'' shocks form via plasma instabilities and self-generated magnetic fields. Laboratory experiments at large laser facilities can achieve the conditions necessary for the formation of collisionless shocks, and will provide a unique avenue for studying the nonlinear physics of shock waves. We are performing a series of experiments at the Omega and Omega-EP lasers in Rochester, NY, where collisionless shock conditions will be generated by the two high-speed plasma flows resulting from laser ablation of solid targets using 10kJ to 20 kJ of laser energy. The experiments will aim to answer several questions of relevance to collisionless shock physics: the importance of the electromagnetic filamentation (Weibel) instability in shock formation, the self-generation of magnetic fields in shock collisions, the influence of external magnetic fields on shock formation, and the signatures of particle acceleration in shocks. This paper will present simulations of our experimental results [1]. Our plan for experiments on the National Ignition Facility in Livermore, CA, using up to 1.8 MJ of laser energy will also be presented. [4pt] [1] H. S. Park et al., High Energy Density Physics, 8, 38 (2012).

Park, Hye-Sook; Kugland, N.; Ross, J.; Remington, B.; Plechaty, C.; Ryutov, D.; Spitkovsky, A.; Gregori, G.; Meinecke, J.; Sakawa, Y.; Morita, T.; Fiksel, G.; Koenig, M.; Grosskopf, M.; Presura, R.

2012-10-01

19

Laboratory experiments and space phenomena  

NASA Astrophysics Data System (ADS)

It is noted that two types of convection have been observed in the laboratory model of the magnetosphere: viscous convection and convection arising from field lines common to both the magnetosphere and artificial solar wind. With a southward field component in the solar wind, convection from the sun is observed in the polar cap, but with a large northward component, convection is directed toward the sun. A merging of the field lines is found to occur in the cleft. With the southward component, a visor appears in front of the boundary of the magnetosphere. The decay of the visor into a small magnetic structure is observed. The formation of an induced magnetosphere having a magnetic tail is shown in the experiments of the simulated conditions near nonmagnetic bodies with a plasma shell. Also investigated is a combined induced-intrinsic magnetosphere.

Podgornyi, I.

20

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

21

Progress in Laboratory Gravitational Experiments in Hust Group  

NASA Astrophysics Data System (ADS)

We briefly review recent progress of laboratory gravitational experiments conducted in our group, which include the determination of the gravitational constant G, the test of the gravitational inverse-square law, and the test of the Equivalence Principle.

Luo, Jun; Tu, Liang-Cheng; Shao, Cheng-Gang; Hu, Zhong-Kun; Yang, Shan-Qing; Li, Qing; Tan, Wen-Hai

2013-09-01

22

Rotating, hydromagnetic laboratory experiment modelling planetary cores  

NASA Astrophysics Data System (ADS)

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

Kelley, Douglas H.

2009-10-01

23

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

Microsoft Academic Search

Quantitative interpretation of MT anomalies in volcanic regions requires laboratory measurements of electrical conductivities of natural magma compositions. The electrical conductivities of three lava compositions from Mount Vesuvius (Italy) have been measured using an impedance spectrometer. Experiments were conducted on both glasses and melts between 400 and 1300°C, at both ambient pressure in air and high pressures (up to 400

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

2008-01-01

24

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

25

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

26

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

27

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

28

Constraints on Mantle Electrical Conductivity from Field and Laboratory Measurements  

Microsoft Academic Search

both in terms of magnitude and distribution of data residuals. Smooth models in the sense of minimum first and second derivatives of log(conductivity) with log(depth) show conductivities increasing from 0.01 S\\/m 200 km deep to 2 S\\/m at a depth of 2000 km. Geotherms inferred from these conductivities using a laboratory model for the temperature dependence of dry sub- solidus

Steven Constable

1993-01-01

29

An experiment on experiments in a senior laboratory  

NSDL National Science Digital Library

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

Finegold, Leonard; Hartley, Charles L.

2006-05-17

30

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

31

21 CFR 58.130 - Conduct of a nonclinical laboratory study.  

Code of Federal Regulations, 2013 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...

2013-04-01

32

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

33

Simple vacuum experiments for undergraduate student laboratories  

Microsoft Academic Search

An overview of typical simple experiments, intended for didactic laboratory vacuum classes for undergraduate students majoring in Physics, Physics Engineering and Material Sciences, is presented.For all the experiments, the students perform actual measurements of characteristics of different vacuum components or material properties and compare the obtained results with the values tabulated in the literature: pumping speed measurements, leak measurements, outgassing

J. M. F. dos Santos

2005-01-01

34

Simple vacuum experiments for undergraduate student laboratories  

Microsoft Academic Search

An overview of typical simple experiments, intended for didactic laboratory vacuum classes for undergraduate students majoring in Physics, Physics Engineering and Material Sciences, is presented. For all the experiments, the students perform actual measurements of characteristics of different vacuum components or material properties and compare the obtained results with the values tabulated in the literature: pumping speed measurements, leak measurements,

J. M. F. dos Santos

2005-01-01

35

Laboratory facility for flexible structure control experiments  

Microsoft Academic Search

A laboratory facility to study various control problems related to flexible mechanical structures is described. Computer, interfacing, and software issues are discussed. A novel proof-mass actuator is presented. A free-free suspended-beam experiment and a skewing-beam experiment are described. Three additional experimental setups at various stages of development are briefly considered

Umit OzgUner; Stephen Yurkovich; Joseph W. Martin; Paul T. Kotnik

1988-01-01

36

Laboratory-based conductivity structure in the mantle transition zone  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

37

Monitoring hydraulic fracture growth: Laboratory experiments  

Microsoft Academic Search

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

Jeroen Groenenboom; Dirkjan B. van Dam

2000-01-01

38

Making Sparklers: An Introductory Laboratory Experiment  

NASA Astrophysics Data System (ADS)

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

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

1995-07-01

39

Laser Mode Structure Experiments for Undergraduate Laboratories.  

ERIC Educational Resources Information Center

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

Phillips, Richard A.; Gehrz, Robert D.

40

Value of Laboratory Experiments for Code Validations  

SciTech Connect

Numerical codes have become indispensable for designing underground structures and interpretating the behavior of geologic systems. Because of the complexities of geologic systems, however, code calculations often are associated with large quantitative uncertainties. This papers presents three examples to demonstrate the value of laboratory(or bench scale) experiments to evaluate the predictive capabilities of such codes with five major conclusions: Laboratory or bench-scale experiments are a very cost-effective, controlled means of evaluating and validating numerical codes, not instead of but before or at least concurrent with the implementation of in situ studies. The design of good laboratory validation tests must identifj what aspects of a code are to be scrutinized in order to optimize the size, geometry, boundary conditions, and duration of the experiments. The design of good and sometimes difficult numerical analyses and sensitivity studies. Laboratory validation tests must involve: Good validation experiments will generate independent data sets to identify the combined effect of constitutive models, model generalizations, material parameters, and numerical algorithms. Successfid validations of numerical codes mandate a close collaboration between experimentalists and analysts drawing from the full gamut of observations, measurements, and mathematical results.

Wawersik, W.R.

1998-12-14

41

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

42

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

43

Measurement of thermal conductivity and heat capacity in an undergraduate physics laboratory  

Microsoft Academic Search

An undergraduate laboratory course experiment on thermal properties of low diffusivity materials is fully described. The experimental setup is of simple construction, not requiring the use of vacuum techniques nor temperature controllers. From the transient regime data, thermal conductivity as well as specific heat capacity can be determined.

J. H. Talpe; V. I. Bekeris; C. E. Acha

1990-01-01

44

Laboratory experiments on mountain-induced rotors  

NASA Astrophysics Data System (ADS)

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

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

2010-09-01

45

On-Campus and Online Virtual Laboratory Experiments with LabVIEW  

Microsoft Academic Search

Virtual laboratory experiments for electronics course in undergraduate electrical engineering curriculum have been developed using data acquisition board (DAQ) and National Instruments LabVIEWtrade software package. These applications are suitable for Internet delivery where students can conduct the experiments online. The undergraduate laboratories have been poorly equipped due to rising cost of laboratory instruments. This trend has created a strong market

Hasanul A. Basher; Saliman A. Isa

2006-01-01

46

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

47

Simple undergraduate lab experiment showing the quantized conductance of nanocontacts  

NSDL National Science Digital Library

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

Candela, D.

2012-06-06

48

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

49

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

50

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

51

Critical experiments at Pacific Northwest Laboratory  

SciTech Connect

Critical experiment programs at the Critical Mass Laboratory (CML) of the Pacific Northwest Laboratory (PNL) are discussed and projected requirements for critical experiment data in different areas of the fuel recycle; processing, fabrication, storage and shipment are reviewed. Recent experiments at the CML include: Criticality Measurements on (1) homogeneous aqueous solutions of Pu and U (up to 60 wt% Pu), (2) plutonium nitrate solutions with Cd as a soluble absorber, (3) heterogeneous lattice assemblies of low enriched uranium with high reactivity hold down achieved by means of a soluble absorber (boron) in the water moderator, (4) lattice assemblies with LWR type fuel in water containing gadolinium nitrate as soluble absorber, (5) interacting arrays of bottles of Pu solutions and (6) interacting arrays of bundles of low enriched uranium lattice assemblies in water with lead, steel and depleted uranium reflectors. Neutronic measurements are described wherein neutron flux spatial and spectral mapping have been done with solid state track recorders (SSTR) to provide data on fission rates and neutron spectrum.

Clayton, E.D.; Bierman, S.R.

1983-09-01

52

Scientists conduct largest coastal experiment on record  

NASA Astrophysics Data System (ADS)

Duck, N.C.—Something out of the ordinary has been happening near this quiet, resort town on the Outer Banks. More than 100 coastal scientists, students, and technicians have descended on the Army Corps of Engineer's Waterways Experiment Station primarily to study movement of sediment in the surf zone. In fact, a large percentage of the U.S. near-shore research community has flooded the Duck area to execute the largest coastal experiment ever undertaken. The researchers have brought with them more than 80 computers and an array of exotic gadgets to carry out “DUCK94,” an unprecedented project that has been three years in the making.

Wakefield, Julie

53

Psychiatric Residents' Experience Conducting Disability Evaluations  

ERIC Educational Resources Information Center

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

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

2010-01-01

54

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

SciTech Connect

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

Johnson, B.

1992-12-31

55

Effects of solute concentration-dependent surface tension on unsaturated flow: Laboratory sand column experiments  

Microsoft Academic Search

Laboratory and numerical modeling studies were conducted to investigate the effects of solute concentration-dependent surface tension on unsaturated flow and transport of a dissolved organic compound. The laboratory experiments were conducted in a 2 m long unsaturated\\/saturated sand column with a water table at the bottom and butanol as the solute. Pressure head was measured with tensiometers connected to pressure

James E. Smith; Robert W. Gillham

1999-01-01

56

Virtual geotechnical laboratory experiments using a simulator  

NASA Astrophysics Data System (ADS)

The details of a test simulator that provides a realistic environment for performing virtual laboratory experimentals in soil mechanics is presented. A computer program Geo-Sim that can be used to perform virtual experiments, and allow for real-time observations of material response is presented. The results of experiments, for a given set of input parameters, are obtained with the test simulator using well-trained artificial neural-network-based soil models for different soil types and stress paths. Multimedia capabilities are integrated in Geo-Sim, using software that links and controls a laser disc player with a real-time parallel processing ability. During the simulation of a virtual experiment, relevant portions of the video image of a previously recorded test on an actual soil specimen are dispalyed along with the graphical presentation of response from the feedforward ANN model predictions. The pilot simulator developed to date includes all aspects related to performing a triaxial test on cohesionless soil under undrained and drained conditions. The benefits of the test simulator are also presented.

Penumadu, Dayakar; Zhao, Rongda; Frost, David

2000-04-01

57

Laboratory experiments simulating solar wind driven magnetospheres  

SciTech Connect

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

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

2009-04-15

58

The Madison Plasma Dynamo Experiment: a Laboratory for Astrophysics  

NASA Astrophysics Data System (ADS)

Plasma experiments in laboratory settings offer the opportunity to address fundamental aspects of the solar dynamo, magnetism in solar and stellar atmospheres, and instabilities that may play important roles in astrophysical systems. The newly constructed Madison Plasma Dynamo Experiment (MPDX) Is a platform for investigating the self-generation of magnetic fields and related processes in large, weakly magnetized, fast flowing, and hot (conducting) plasmas. Planned experiments will probe questions that are of crucial importance to heliophysics in the solar interior, atmosphere and wind. These include studying large and small scale dynamos, varying between laminar and turbulent regimes, studying stratified convection and magnetic buoyancy instabilities, and studying dissipation processes in collisionless plasmas. In addition, MPDX will allow us to study the basic physical processes underlying magnetic reconnection and flares in the solar atmosphere, the nature of CMEs, and the interactions between planetary magnetospheres and the solar wind. Results from these experiments will create the benchmarks necessary for validating heliospheric codes used to mode our Sun and forecast solar activity. Laboratory plasma experiments are likely to contribute new understanding complementary to the traditional observational and modeling approach normally used by space physicists.

Brown, Benjamin; Nornberg, M. D.; Forest, C. B.; Zweibel, E. G.; Wallace, J. B.; Clark, M.; Spence, E. J.; Rahbarnia, K.; Kaplan, E. J.; Taylor, N. Z.

2012-05-01

59

Laboratory experiments on nonlinear Electron MHD phenomena  

NASA Astrophysics Data System (ADS)

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

Stenzel, Reiner

2006-04-01

60

CSI flight experiment projects of the Naval Research Laboratory  

Microsoft Academic Search

The Naval Research Laboratory (NRL) is involved in an active program of CSI flight experiments. The first CSI flight experiment of the Naval Research Laboratory, the Low Power Atmospheric Compensation Experiment (LACE) dynamics experiment, has successfully measured vibrations of an orbiting satellite with a ground-based laser radar. The observations, made on January 7, 8 and 10, 1991, represent the first

Shalom Fisher

1993-01-01

61

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

62

Systems integration test laboratory application & experiences  

Microsoft Academic Search

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

Melvyn Rimer; Michael Falco; Michael J. Solan

1991-01-01

63

Meteorological Development Laboratory Student Career Experience Program  

NASA Astrophysics Data System (ADS)

The National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) provides weather, hydrologic, and climate forecasts and warnings for the protection of life and property and the enhancement of the national economy. The NWS's Meteorological Development Laboratory (MDL) supports this mission by developing meteorological prediction methods. Given this mission, NOAA, NWS, and MDL all have a need to continually recruit talented scientists. One avenue for recruiting such talented scientist is the Student Career Experience Program (SCEP). Through SCEP, MDL offers undergraduate and graduate students majoring in meteorology, computer science, mathematics, oceanography, physics, and statistics the opportunity to alternate full-time paid employment with periods of full-time study. Using SCEP as a recruiting vehicle, MDL has employed students who possess some of the very latest technical skills and knowledge needed to make meaningful contributions to projects within the lab. MDL has recently expanded its use of SCEP and has increased the number of students (sometimes called co- ops) in its program. As a co-op, a student can expect to develop and implement computer based scientific techniques, participate in the development of statistical algorithms, assist in the analysis of meteorological data, and verify forecasts. This presentation will focus on describing recruitment, projects, and the application process related to MDL's SCEP. In addition, this presentation will also briefly explore the career paths of students who successfully completed the program.

McCalla, C., Sr.

2007-12-01

64

Sediment response to moving rainstorms: laboratory experiments  

NASA Astrophysics Data System (ADS)

The soil material transported by surface runoff is an important factor, for example, in water quality management, environmental decision making, urban management and ecosystems sustainability. This study aims at contributing to increased understanding of water erosion factors and processes. The main objective is to quantify experimentally the soil loss caused by both non-moving and moving rainstorms. The importance of storm movement, due to the combined effect of wind and rain, on surface flows has long been recognised, at scales ranging from headwater scales to larger catchment basins. All these processes (rainfall, wind, runoff, soil erosion) involved are germane for investigation at different scales. In this study, laboratory experiments were carried out using several soil flumes and a movable sprinkling-type rainfall simulator. To simulate moving rainstorms, the rainfall simulator was moved upstream and downstream over the soil surface at different speeds. During runoff events overland flow and sediment transport were measured in order to determine hydrographs and sediment production over time. The size distribution of the eroded material is governed by the capacity of the flowing water to transport it. Granulometric curves obtained through conventional hand sieving and optical spectrophotometer method (material below 0.250 mm) were constructed. Distinct hydrologic responses for storms moving upstream and downstream were identified. Soil loss by sheet erosion caused by downstream moving rainstorms was higher than that caused by identical upstream moving rainfall storms or non-moving storms. The results also show that storm movement, affecting spatial and temporal distributions of rainfall, has a marked influence on the granulometric characteristics of sediments transported by overland flow during the runoff event. Storms moving downslope are the most potentially hazardous in terms of erosion.

de Lima, J. L. M. P.

2009-04-01

65

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

66

Do-It-Yourself Experiments for the Instructional Laboratory  

ERIC Educational Resources Information Center

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

Craig, Norman C.; Hill, Cortland S.

2012-01-01

67

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

68

PC-Based Transport Laboratory Experiments  

Microsoft Academic Search

The transport laboratory course in Chemical Engineering at Michigan Tech has been offered to undergraduate juniors as a 2-credit required course since 2000. The laboratory equipment has been newly designed to accommodate an in-line digital computer for data acquisition. The chemical engineering faculty focused on three essential elements in selecting a system: safe, compact and inexpensive. Based on an examination

Nam K. Kim

69

Databases, Problem Solving and Laboratory Experiences.  

ERIC Educational Resources Information Center

|Describes a problem-solving activity integrating a laboratory investigation with a database activity using Appleworks. Presents typical displays of the databases. The objective of the laboratory was to determine the identity of a pure substance by measuring physical properties and searching the database. (Author/YP)|

Strickland, A. W.; Hoffer, T.

1989-01-01

70

An Experiment in Heat Conduction Using Hollow Cylinders  

ERIC Educational Resources Information Center

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

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

2011-01-01

71

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

72

Comparative thermal conductivity measurements at Sandia National Laboratories. [Pyroceram  

SciTech Connect

A detailed examination has been made on the use of the comparative method for measuring the thermal conductivity of solid materials. Existing data analysis methods are discussed and new techniques, based on generalized linear least squares methods, are presented. An error analysis is made to determine the potential accuracy, reproducibility, and repeatability of the technique. For the case in which the reference conductivity is known to a relative accuracy of +-5%, the overall relative accuracy of the measurement is shown to be about +-6%. Experimental data are presented for the conductivities of commonly used reference materials; Pyrex 7740, Pyroceram 9606, Inconel 718, and Armco iron. Data are also given for two potential reference materials: fused silica and 304 stainless steel.

Sweet, J.N.; Roth, E.P.; Moss, M.; Haseman, G.M.; Anaya, J.A.

1986-06-01

73

Systems integration test laboratory application experiences  

SciTech Connect

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.

Rimer, M.; Falco, M.; Solan, M.J. (Grumman Space Systems Division, Bethpage, NY (USA))

1991-01-10

74

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

75

Variable Conductance Heat Pipes from the Laboratory to Space.  

National Technical Information Service (NTIS)

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

J. P. Kirkpatrick

1973-01-01

76

Principles of radio: a laboratory experiment  

Microsoft Academic Search

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 data-acquisition system with the DataStudio software.

Yaakov Kraftmakher

2002-01-01

77

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

78

Measuring Hydraulic Conductivity to Wilting Point Using Polymer Tensiometers in an Evaporation Experiment  

Microsoft Academic Search

The polymer tensiometer is a novel instrument to measure soil water pressure heads from saturation to permanent wilting conditions. We used tensiometers of this type in an experiment to determine the hydraulic properties of evaporating soil samples in the laboratory. Relative errors in the hydraulic conductivity function in the wet part were high due to the relatively low accuracy of

A. Durigon; H. P. A. Gooren; Lier van Q. D; K. Metselaar

2011-01-01

79

Collaborative learning experience in a freshman materials laboratory exercise  

Microsoft Academic Search

Freshmen students are often treated as incapable of operating without carefully detailed instructions for many types of laboratory experiences. At Purdue-Kokomo, six different laboratory exercises are provided for our freshmen taking the initial course in Materials and Processing, MET 141. In the past, detailed written laboratory instructions were provided, spelling out exactly how to make the necessary measurements, how to

J. R. Williams

1995-01-01

80

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

81

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

82

Review of subsidence prediction research conducted at Sandia National Laboratories  

SciTech Connect

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

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

1982-04-01

83

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

84

Experiences of Mentors Training Underrepresented Undergraduates in the Research Laboratory  

PubMed Central

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

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

2013-01-01

85

A Laboratory Experiment on the Statistical Theory of Nuclear Reactions  

ERIC Educational Resources Information Center

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

Loveland, Walter

1971-01-01

86

A Laboratory Experiment on the Statistical Theory of Nuclear Reactions  

ERIC Educational Resources Information Center

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

Loveland, Walter

1971-01-01

87

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.

88

Work Experience of Certified Laboratory Assistants.  

ERIC Educational Resources Information Center

|Questionnaires concerning the nature of work performed and the work setting, plans for continuing formal education, and opinions regarding the relevancy of training received were sent to all individuals (3,282) certified by the Board of Certified Laboratory Assistants (CLA's) since certification began in 1965. Some findings from the 970 returned…

National Council on Medical Technology Education, Bethesda, MD.

89

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.

90

Laboratory Experiment on Electrokinetic Remediation of Soil  

ERIC Educational Resources Information Center

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

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

2011-01-01

91

Laboratory experiments on nonlinear Electron MHD phenomena  

Microsoft Academic Search

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

Reiner Stenzel

2006-01-01

92

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.

Day, J.; McPherson, A.

1992-01-01

93

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

Code of Federal Regulations, 2011 CFR

...and are laboratories required to conduct it? 40.89 Section 40.89 Transportation...and are laboratories required to conduct it? (a) Specimen validity testing is the evaluation of the specimen to determine if it is consistent with normal human...

2011-10-01

94

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

PubMed Central

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

Hill, A. E.

1990-01-01

95

Recycle with Heating: A Laboratory Experiment.  

ERIC Educational Resources Information Center

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

Foord, A.; Mason, G.

1985-01-01

96

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

ERIC Educational Resources Information Center

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

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

2006-01-01

97

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

ERIC Educational Resources Information Center

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

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

2006-01-01

98

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

99

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

Microsoft Academic Search

This quasi-experimental research study examined the effect of computer simulations and hands-on laboratory experiments in enhancing conceptual understanding and alleviating misconceptions of organic chemistry reaction mechanisms. Subjects were sixty-nine sophomore-level organic chemistry students enrolled in four laboratory sections. Laboratory sections were stratified across instructor and randomly assigned to serve as a control or treatment laboratory. Students in the control group

Barbara A. Gaddis

2001-01-01

100

Blanket technology experiments at Argonne National Laboratory  

NASA Astrophysics Data System (ADS)

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

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

1988-02-01

101

Students Designing their Own Laboratory Experiments - The Experience of 4 Semesters  

Microsoft Academic Search

An undergraduate environmental engineering laboratory class was revised in Fall 1999 to include an open experiment in a ddition to traditional experiments. Each student group identified a problem, designed an experiment to address the problem, performed the experiment, and documented the results with laboratory reports. A variety of topics were selected, including remediation of acid mine drainage and evaluating indoor

Joseph R. V. Flora; Adrienne T. Cooper

102

[Our experience with outside laboratory quality control].  

PubMed

The results from the national outside laboratory qualitative control of the clinical diagnostic laboratory investigations for the period September 1975 -- May 1977 were described. The following interlaboratory discrepancy was found on base of a systematic analysis of the data from the last two ring-like check-ups, November 1976 and May 1977, exressed by the variation coefficient (V.C. %); total protein, sodium, potassium and chlorides -- under 10%; cholesterol, urea and total fats -- between 10 and 20%; calcium, phosphorus, iron and creatinine -- over 20%. The highest per cent of admissible results are found with total protein -- to 85%; cholesterol -- to 70.38%; glucosa -- to 73.17%, urea -- to 69.23%, potassium -- to 59.46%, chlorides -- to 57.9%. With sodium, phosphorus, calcium, iron creatinine and uric acid the "admissibility" fluctuates about or under 50 per cent. The values of the qualitative-control indices discussed are comparable with the values obtained from them in the interlaboratory comparisons of other countries. PMID:494628

Dochev, D; Arakasheva, V; Nashkov, A; Tsachev, K

1979-01-01

103

Inventory Control. Easily Made Electronic Device for Conductivity Experiments.  

ERIC Educational Resources Information Center

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

Gadek, Frank J.

1987-01-01

104

"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

105

Simple Laboratory Experiment for Illustrating Soil Respiration.  

ERIC Educational Resources Information Center

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

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

1997-01-01

106

A Simple Photochemical Experiment for the Advanced Laboratory.  

ERIC Educational Resources Information Center

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

Rosenfeld, Stuart M.

1986-01-01

107

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

108

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...

109

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

110

Active and laboratory experiments in space plasma physics  

NASA Astrophysics Data System (ADS)

This report focuses on active experiments in space as well as laboratory experiments which are directly related to space phenomena. The active experiments involve particle releases in the CRESS and AMPTE missions. Unexpected results such as the motion of the plasma triggered several interesting computer simulations and a laboratory experiment which will be reviewed. Critical Ionization Phenomena will be discussed in this context. A recent release over Arecibo was used to create a “plasma lens” to focus radiation from the HF heater beam. The higher power triggered several nonlinear processes. Advances in plasma sources and diagnostics have made it possible to scale many laboratory experiments. Discussed here are experiments on Alfvén waves generated by a localized source, 3D magnetic field line reconnection, three dimensional magnetized double layers and simulations of a tethered satellite.

Gekelman, Walter

1995-05-01

111

Fertilizers mobilization in alluvial aquifer: laboratory experiments  

NASA Astrophysics Data System (ADS)

In alluvial plains, intensive farming with conspicuous use of agrochemicals, can cause land pollution and groundwater contamination. In central Po River plain, paleo-channels are important links between arable lands and the underlaying aquifer, since the latter is often confined by clay sediments that act as a barrier against contaminants migration. Therefore, paleo-channels are recharge zones of particular interest that have to be protected from pollution as they are commonly used for water supply. This paper focuses on fertilizer mobilization next to a sand pit excavated in a paleo-channel near Ferrara (Italy). The problem is approached via batch test leaking and columns elution of alluvial sediments. Results from batch experiments showed fast increase in all major cations and anions, suggesting equilibrium control of dissolution reactions, limited availability of solid phases and geochemical homogeneity of samples. In column experiments, early elution and tailing of all ions breakthrough was recorded due to preferential flow paths. For sediments investigated in this study, dispersion, dilution and chemical reactions can reduce fertilizers at concentration below drinking standards in a reasonable time frame, provided fertilizer loading is halted or, at least, reduced. Thus, the definition of a corridor along paleo-channels is recommended to preserve groundwater quality.

Mastrocicco, M.; Colombani, N.; Palpacelli, S.

2009-02-01

112

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

113

Slew Maneuvers of Spacecraft Control Laboratory Experiment (SCOLE).  

National Technical Information Service (NTIS)

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 ...

Y. P. Kakad

1992-01-01

114

Laboratory Experiments on Diapycnal Mixing in Stratified Fluids.  

National Technical Information Service (NTIS)

Our turbulent length scale, velocity and diffusivity scalings are compared with data from other numerical, laboratory and field experiments. Comparison is made with reference to the turbulence intensity measure epsilon/nu N squared. We showed that our tur...

G. N. Ivey J. Imberger K. B. Winters M. E. Barry

2001-01-01

115

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

116

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…

Karlsson, Goran; Ivarsson, Jonas; Lindstrom, Berner

2013-01-01

117

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

118

The Science Laboratory Experiences of Utah's High School Students  

ERIC Educational Resources Information Center

This research investigated the extent to which science laboratory experiences encountered by Utah high school students aligned with reform efforts outlined in national standards documents. Through both quantitative and qualitative methods the findings revealed that while there were instances of alignment found between science laboratory…

Campbell, Todd

2007-01-01

119

[Experience in organizing the operations of a large histopathology laboratory].  

PubMed

In connection with the organization of large centralized pathology departments serving up to 4-6 thousand beds or more in hospitals the use of routine methods of work of histological laboratories becomes unacceptable. The authors shares his experience in organization work of a large histopathological laboratories, suggesting available devices increasing the labour productivity and culture and requiring no scarce glassware. PMID:6362622

Konstantinov, G S

1983-01-01

120

Hands-on laboratory experience in teaching-learning physiology  

Microsoft Academic Search

RANDALL, WALTER C., AND TIMOTHY BURKHOLDER. Hands-on laboratory experience in teaching-learning physiology. Am. J. Physiol. 259 (Adv. Physiol. Educ. 4): S4-S7, 1990.- Reactivation of several model 5 (vacuum tube) Grass poly- graphs for active hands-on laboratory experiments by small student groups, in contrast to demonstrations and pretaped illustrations of physiological principles, resulted in remarkable rejuvenation of interest and excitement for

WALTER C. RANDALL; TIMOTHY BURKHOLDER

121

Discrepancies Between Laboratory Shock Experiments on Minerals and Natural Events  

NASA Astrophysics Data System (ADS)

Numerous laboratory shock recovery experiments performed over the past 50 years have provided substantial data on the effects of shock waves on rocks and minerals. However, it has become increasingly clear that the pressure "calibrations" based on shock effects observed in these experiments are inconsistent with interpretations based on static high-pressure data. A fundamental question is whether shock pressures are somehow different from static high pressures. Fifty years ago, many journal reviewers doubted that phase transformations could take place on a sub-microsecond time scale. Shock wave workers responded by invoking "special" properties of shock compression. However, all available evidence is consistent with the hypothesis that phase transitions under shock pressure are no different from phase transitions under static high pressures. The discrepancies noted above result from the fact that the parameter space, especially shock pressure duration, accessible to shock recovery experiments is so small by comparison with natural events. Furthermore virtually all shock recovery experiments on rocks and minerals have used high impedance sample containers, with the result that the samples have been subjected to thermodynamic loading paths substantially from a natural event. Consider the case of a chondritic meteorite made up of minerals having a wide range of shock properties. In a natural shock event the transient (nano-second scale) shock pressure at the shock front can vary by as much as an order of magnitude from grain to grain or even within a single grain. There are corresponding local differences in shock temperature. Assuming a mineral grain size of about a mm, the pressure inhomogeneities will equilibrate in less than a microsecond, wheras the temperature inhomogenities will require seconds to equilibrate. Recent studies of high-pressure phases in meteorites have provided evidence for pressure durations in the range of seconds, long enough for high pressure phases to crystallize from a melt or transform via solid-solid mechanisms. In contrast, the sample shock loaded in a laboratory experiment in a high impedance container reaches peak pressure via a series of shock reflections. As a result, shock and post-shock temperatures correspond to a sample naturally shocked to a substantially lower ( 20-60 %, dependent on sample mineralogy and porosity) equilibrium pressure. The effect of differences in the shock properties of the individual minerals is also greatly reduced. Shock pressure durations in the range of seconds have been inferred from studies of naturally shocked meteorites, whereas the effective duration of a shock recovery experiment is about a microsecond. Shock effects that involve reconstructive phase transformations, and therefore nucleation and growth, are highly dependent on both temperature and duration. Finally, the laboratory experiments are conducted on a small scale; samples cool from their equilibrium post-shock temperature in seconds. In a large natural event, the cooling time can be thousands of years.

de Carli, P. S.; Xie, Z.; Sharp, T. G.

2009-12-01

122

Procedure Manuals for the Comparative Systems Laboratory Experiments.  

ERIC Educational Resources Information Center

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

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

123

Experiences with the Webware, interfaces and networking experimental laboratory  

Microsoft Academic Search

This paper describes our experiences with the Webware, Interfaces and Networking Experimental (WINE) Laboratory. The WINE Lab was created to assist in teaching the topics of computer networks, user interfaces and webware. The goal of the lab is to provide students the opportunity to complete projects, experiment with relevant techniques and make connections between topics with resources not available in

David C. Brown; Isabel F. Cruz; David Finkel; Robert E. Kinicki; Craig E. Wills

2000-01-01

124

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

125

Soap from Nutmeg: An Integrated Introductory Organic Chemistry Laboratory Experiment  

Microsoft Academic Search

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

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

2002-01-01

126

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...

127

Identification Design for a Flexible Beam Laboratory Experiment  

Microsoft Academic Search

Recent experience with system identification design for a flexible beam laboratory experiment controller design is discussed. Among the limitations faced were the presence of unmodeled high frequency modes and the use of an accelerometer as the primary motion sensor. These limitations motivated the development of a novel robust identification approach which is applicable to a large class of flexible structures.

G. A. McGraw

1991-01-01

128

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…

Claycomb, J. R.

2009-01-01

129

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

130

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

131

Laboratory Experiment of Saltwater Intrusion into Freshwater Aquifer  

NASA Astrophysics Data System (ADS)

It is important for safety assessment of high-level radioactive waste geologic disposal to understand groundwater flow in deep underground accurately. Especially groundwater flow in the coastal area considered to be quite complex that involves density and hydraulic gradient driven flow of freshwater and saltwater. Furthermore, bentonite, which is one of the favored artificial barrier materials, may not swell very well in saltwater as it does in freshwater, and therefore may not provide a reliable seal if salinity is high enough. In order to understand the behavior of saltwater intrusion into freshwater in deep underground, we constructed a laboratory equipment "Mini-MACRO" named after the original large scale MACRO (MAss transport Characterization in host ROck) and aimed to increase a precision and efficiency of experiment. Mini-MACRO equipment consists of three parts: a sandbox (0.5m x 0.25m x 0.1m) and each reservoir tank for saltwater and freshwater. Saltwater intrusion experiments are conducted using glass beads (sub-millimeter in diameter) and colored saltwater in the sandbox with a transparent face plate to allow visual observation. In the present paper we summarize the concept of the equipment design and the results of the experiment that we created several cases of experimental conditions to observe the saltwater intrusion behavior against various hydraulic gradients and densities of saltwater. This equipment contributes to the better understanding of saltwater intrusion behavior and to increasing confidence in modeling methodology of groundwater flow and mass transport in deep underground through comparison with numerical analysis. We believe that it is crucial for the safety assessment of geologic disposal to integrate this knowledge.

Maekawa, K.; Karasaki, K.; Takasu, T.

2006-12-01

132

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

133

Controversy surrounding the Experiment conducted to prove the Vortex Theory  

NASA Astrophysics Data System (ADS)

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

Vasiliev, Victor; Moon, Russell

2006-05-01

134

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

135

Laboratory Experiments for Seawater Intrusion into Freshwater Aquifer with Heterogeneity  

NASA Astrophysics Data System (ADS)

It is important for safety assessment of high-level radioactive waste geologic disposal to understand groundwater flow in deep underground accurately. Especially, groundwater flow in the coastal area is considered to be quite complex that involves density and hydraulic gradient driven flow of freshwater and seawater. In order to understand the behavior of seawater intrusion into freshwater in deep underground, we constructed a laboratory equipment, 'Mini-MACRO' (MAss transport Characterization in host ROck). Mini-MACRO consists of three parts: a sandbox (0.5m x 0.25m x 0.1m) and a reservoir tank on each side containing saltwater simulating seawater and freshwater, respectively. Seawater intrusion experiments are conducted using glass beads (sub- millimeter in diameter) and colored saltwater in the sandbox with a transparent face plate to allow visual observation. We created several cases of experimental conditions to observe the seawater intrusion behavior into two-layered stratum against various hydraulic gradients and densities of saltwater resembling the so-called Henry Problem. We confirmed that the results using this equipment match numerical results under simple heterogeneous condition. These results contribute to the better understanding of seawater intrusion behavior and to increasing confidence in modeling methodology of groundwater flow and mass transport in deep underground through comparison with numerical analysis. We believe that it is crucial for the safety assessment of geologic disposal to integrate this knowledge.

Maekawa, K.; Karasaki, K.; Takasu, T.

2007-12-01

136

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

137

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

SciTech Connect

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

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

2009-03-01

138

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

Microsoft Academic Search

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

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

2004-01-01

139

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.

140

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.

141

WAVES: towards real time laboratory experiments in cyberspace  

Microsoft Academic Search

This paper describes the architecture of a Web-based audio\\/video educational system for real-time laboratory experiments through the Internet. The goal of the WAVES (Web-based Audio Video Educational Systems) project is to develop an open and integrated platform for online laboratory experimentation, computer simulation, and course instruction using the Internet for research and teaching in modeling, design, analysis, and control of

Mo Fu; Christopher Yeo; Yuetong Lin; Fei-Yue Wang

2001-01-01

142

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

143

Laboratory experiments on planetary and stellar convection performed on spacelab 3.  

PubMed

Experiments on thermal convection in a rotating, differentially heated hemispherical shell with a radial buoyancy force were conducted in an orbiting microgravity laboratory. A variety of convective structures, or planforms, were observed, depending on the magnitude of the rotation and the nature of the imposed heating distribution. The results are compared with numerical simulations that can be conducted at the more modest heating rates, and suggest possible regimes of motion in rotating planets and stars. PMID:17742634

Hart, J E; Toomre, J; Deane, A E; Hurlburt, N E; Glatzmaier, G A; Fichtl, G H; Leslie, F; Fowlis, W W; Gilman, P A

1986-10-01

144

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

145

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

146

Interactive screen experiments—innovative virtual laboratories for distance learners  

NASA Astrophysics Data System (ADS)

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 (piCETL) in the production and technology of the virtual laboratory resources, interactive screen experiments, and the benefits and drawbacks of such resources. We also explore the motivations behind current implementation of interactive screen experiments and examine evaluation strategies and outcomes through a series of case studies.

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

2009-07-01

147

On integrating large eddy simulation and laboratory turbulent flow experiments.  

PubMed

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

Grinstein, Fernando F

2009-07-28

148

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

149

Does the lack of hands-on experience in a remotely delivered laboratory course affect student learning?  

Microsoft Academic Search

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 students with their on-campus counterparts in a junior-level fluid mechanics laboratory course

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

2006-01-01

150

Large-size space laboratory for biological orbit experiments.  

PubMed

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

Kondyurin, A

2001-01-01

151

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

NASA Astrophysics Data System (ADS)

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

Gaddis, Barbara A.

2001-12-01

152

A Semi-Batch Reactor Experiment for the Undergraduate Laboratory  

ERIC Educational Resources Information Center

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

Derevjanik, Mario; Badri, Solmaz; Barat, Robert

2011-01-01

153

A Semi-Batch Reactor Experiment for the Undergraduate Laboratory  

ERIC Educational Resources Information Center

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

Derevjanik, Mario; Badri, Solmaz; Barat, Robert

2011-01-01

154

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

NASA Astrophysics Data System (ADS)

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

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

2003-03-01

155

A control laboratory plant to experiment with hybrid systems  

Microsoft Academic Search

A multivariable test-bed for research and teaching in hybrid system is presented. The process control laboratory plant uses standard industrial components, which introduces more realism and robustness into the experiments with hybrid systems. The paper describes the plant, mathematical modeling of the system and an illustrative experiment. Moreover, criteria for the selection of the hardware\\/software platform for the real-time implementation

A. Gambier; T. Miksch; E. Badreddin

2003-01-01

156

The student perspective of high school laboratory experiences  

Microsoft Academic Search

High school science laboratory experiences are an accepted teaching practice across the nation despite a lack of research evidence to support them. The purpose of this study was to examine the perspective of students---stakeholders often ignored---on these experiences. Insight into the students' perspective was explored progressively using a grounded theory methodology. Field observations of science classrooms led to an open-ended

R. Mitch Lambert

2009-01-01

157

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

158

How can laboratory plasma experiments contribute to space and &astrophysics?  

NASA Astrophysics Data System (ADS)

Plasma physics plays key role in a wide range of phenomena in the universe, from laboratory plasmas to the magnetosphere, the solar corona, and to the tenuous interstellar and intergalactic gas. Despite the huge difference in physical scales, there are striking similarities in plasma behavior of laboratory and space plasmas. Similar plasma physics problems have been investigated independently by both laboratory plasma physicists and astrophysicists. Since 1991, cross fertilization has been increased among laboratory plasma physicists and space physicists through meeting such as IPELS [Interrelationship between Plasma Experiments in the Laboratory and Space] meeting. The advances in laboratory plasma physics, along with the recent surge of astronomical data from satellites, make this moment ripe for research collaboration to further advance plasma physics and to obtain new understanding of key space and astrophysical phenomena. The recent NRC review of astronomy and astrophysics notes the benefit that can accrue from stronger connection to plasma physics. The present talk discusses how laboratory plasma studies can contribute to the fundamental understandings of the space and astrophysical phenomena by covering common key physics topics such as magnetic reconnection, dynamos, angular momentum transport, ion heating, and magnetic self-organization. In particular, it has recently been recognized that "physics -issue- dedicated" laboratory experiments can contribute significantly to the understanding of the fundamental physics for space-astrophysical phenomena since they can create fundamental physics processes in controlled manner and provide well-correlated plasma parameters at multiple plasma locations simultaneously. Such dedicated experiments not only can bring about better understanding of the fundamental physics processes but also can lead to findings of new physics principles as well as new ideas for fusion plasma confinement. Several dedicated experiments have provided the fundamental physics data for magnetic reconnection [1]. Linear plasma devices have been utilized to investigate Whistler waves and Alfven wave phenomena [2,3]. A rotating gallium disk experiment has been initiated to study magneto-rotational instability [4]. This talk also presents the most recent progress of these dedicated laboratory plasma research. 1. M. Yamada et al., Phys. Plasmas 4, 1936, (1997) 2. R. Stenzel, Phys. Rev. Lett. 65, 3001 (1991) 3. W. Gekelman et al, Plasma Phys. Contr. Fusion, v42, B15-B26, Suppl.12B (2000) 4. H. Ji, J. Goodman, A. Kageyama Mon. Not. R. Astron. Soc. 325, L1- (2001)

Yamada, M.

159

The software engineering laboratory: an operational software experience factory  

Microsoft Academic Search

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

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

1992-01-01

160

Hyporheic exchange with heterogeneous streambeds: Laboratory experiments and modeling  

Microsoft Academic Search

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

Mashfiqus Salehin; Aaron I. Packman; Matthew Paradis

2004-01-01

161

Human Gene Discovery Laboratory: A Problem-Based Learning Experience  

ERIC Educational Resources Information Center

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

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

2006-01-01

162

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

163

LABORATORY EXPERIMENTS TO SIMULATE CO2 OCEAN DISPOSAL  

Microsoft Academic Search

This Final Technical Report summarizes the technical accomplishments of an investigation entitled ''Laboratory Experiments to Simulate COâ 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

Stephen M. Masutani

1999-01-01

164

Control of Spacecraft Control Laboratory Experiment (SCOLE) Slew Maneuvers.  

National Technical Information Service (NTIS)

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 a...

Y. P. Kakad

1987-01-01

165

Dynamics of Spacecraft Control Laboratory Experiment (SCOLE) Slew Maneuvers.  

National Technical Information Service (NTIS)

This is the first of two reports on the dynamics and control of slewing maneuvers of the NASA Spacecraft Control Laboratory Experiment (SCOLE). In this report, the dynamics of slewing maneuvers of SCOLE are developed in terms of an arbitrary maneuver abou...

Y. P. Kakad

1987-01-01

166

Human Gene Discovery Laboratory: A Problem-Based Learning Experience  

ERIC Educational Resources Information Center

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

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

2006-01-01

167

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

168

Laboratory Experiment in Semiconductor Surface-Field Effects  

ERIC Educational Resources Information Center

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

Goodman, F. R.; And Others

1974-01-01

169

Differentiating Biochemistry Course Laboratories Based on Student Experience  

ERIC Educational Resources Information Center

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

Jakubowski, Henry V.

2011-01-01

170

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

171

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. © 2013 by The International Union of Biochemistry and Molecular Biology, 41(5):341-347, 2013. PMID:24078356

Salman Ashraf, S

2013-09-01

172

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

173

Laboratory Experiment in Semiconductor Surface-Field Effects  

ERIC Educational Resources Information Center

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

Goodman, F. R.; And Others

1974-01-01

174

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

175

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

176

ESTIMATION OF THE UNSATURATED HYDRAULIC CONDUCTIVITY OF PEAT SOILS: LABORATORY VERSUS FIELD DATA  

Technology Transfer Automated Retrieval System (TEKTRAN)

As compared to mineral soils, few in-situ measurements are currently available of the unsaturated hydraulic properties of peat soils. We used parameter estimation (inverse) methods to estimate the water retention and hydraulic conductivity functions of drained peat soils from both laboratory and fi...

177

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 ...

178

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

PubMed Central

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

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

2010-01-01

179

An EPR Experiment for the Undergraduate Physical Chemistry Laboratory  

Microsoft Academic Search

An experiment that illustrates the principles of electron paramagnetic resonance spectroscopy in the undergraduate physical chemistry laboratory is described. Students measure the value of g for DPPH and use it to determine the value of g for two inorganic complexes, Cu(acac)2 and VO(acac)2. The students use two instruments: an instructional device that illustrates the principles of EPR and a commercial

R. A. Butera; D. H. Waldeck

2000-01-01

180

A Simple Laboratory Experiment to Measure e\\/k  

Microsoft Academic Search

The measurement of fundamental constants is common practice in instructional laboratories. A number of the equipment manufacturers have developed apparatus for such applications, e.g., the determination of e by the Millikan oil drop method or the determination of the speed of light with fiber optics. Other experiments determine not a single constant, but a combination of constants, e.g., e\\/m by

Fred Inman

2005-01-01

181

Laboratory and Field Soil Washing Experiments with Surfactant Solutions  

Microsoft Academic Search

During the last six years, surfactant solutions have been developed to dissolve or mobilize different NAPL types. These solutions\\u000a were made with anionic surfactants and alcohols, as well as solvents in some cases. Laboratory and field tests were performed\\u000a using these solutions to recover residual NAPL in sediments and etched-glass micromodels. Surfactant washing experiments were\\u000a done on: (1) small sand

Richard Martel; Pierre J. Gelinas; René Lefebvre; Alain Hébert; Stefan Foy; Laurent Saumure; Annie Roy; Nathalie Roy

182

Does competition enhance performance or cheating? A laboratory experiment  

Microsoft Academic Search

In this paper, we experimentally test whether competing for a desired reward does not only affect individuals’ performance, but also their tendency to cheat. Recent doping scandals in sports as well as forgery and plagiarism scandals in academia have been partially explained by “competitive pressures”, which suggests a link between competition and cheating.In our experiment subjects conduct a task where

Christiane Schwieren; Doris Weichselbaumer

2010-01-01

183

Dynamics of pyroclastic density currents studied using scaled laboratory experiments  

NASA Astrophysics Data System (ADS)

We performed a set of scaled laboratory experiments to simulate pyroclastic density currents (PDCs) using dilute mixtures of warm talc powder in air. The experiments were designed to evaluate the effects of topography and bed roughness on current runout, buoyancy reversal and liftoff, and mass partitioning into buoyant plumes. The densimetric and thermal Richardson, Froude, Stokes, and settling numbers for our experiments match those of PDCs and the laboratory currents are fully turbulent, although the experiments have lower Reynolds numbers than PDCs, thus our experiments are dynamically similar to natural currents. Comparisons of currents traversing flat topography or encountering barriers shows that runout distance is not significantly reduced for currents that traverse barriers with height less than 1.5 times the current thickness, but currents do not pass taller barriers. Buoyancy reversals occur in most currents, resulting in liftoff and generation of a buoyant plume. Liftoff occurs near the maximum runout distance for currents traveling over flat topography, but is focused near or above barriers for currents that encounter barriers. Notably, plume formation above barriers can result in reversal of flow direction downstream of the obstruction as portions of the current flow back and feed the rising plume. Greater than half of the initial particle mass composing the density currents usually partitions into the buoyant plumes; that fraction is greater for currents that liftoff closer to the source, thus topographic barriers increase mass partitioning from currents into buoyant plumes.

Manga, M.; Andrews, B.

2011-12-01

184

Ground-based laboratory atomic oxygen calibration experiments  

NASA Astrophysics Data System (ADS)

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

Matcham, Jeremy Stephen

1998-12-01

185

Integration of Laboratory and Field Data for Insight on the Multiwell Experiment Paludal Stimulation  

Microsoft Academic Search

Two stimulation operations have been conducted to date in the paludal zone of the Mesaverde formation in one well, MWX-1, at the DOE's Multiwell Experiment test site in the Piceance Basin near Rifle, Colorado. Problems were encountered in the second stimulation: MWX-1 would not sustain production for several months and post-frac production was less than pre-frac rates. The laboratory program

A. R. Settler; C. J. Raible; B. R. Gall

1985-01-01

186

Unsaturated Flow Through a Fractured-Matrix-Network: Dynamic Pathways in Meso-Scale Laboratory Experiments  

SciTech Connect

We conducted two laboratory experiments at the meter scale in which water was applied to the top of an initially dry, uncemented wall composed of porous bricks. One experiment (Experiment 1) encouraged evaporation and resulting mineral precipitation, while the other (Experiment 2) was designed to minimize these processes. In both cases, processes acting within the fracture network controlled early time behavior, forming discrete pathways and demonstrating fractures to act as both flow conductors and capillary barriers. At a later time, evaporation–mineral precipitation in Experiment 1 constrained flow, strengthening some pathways and starving others. In Experiment 2, the wetted structure took on the appearance of a diffuse plume; however, individual pathways persisted within the wetted structure and interacted, displaying erratic outflow over a wide range of timescales, including switching between pathways. Thus, under conditions of constant supply and both with and without evaporation–mineral precipitation, unsaturated flow through fractured rock can create dynamic preferential pathways.

Wood, Thomas Ronald

2002-12-01

187

Underdense Plasma Lens Experiment at the UCLA Neptune Laboratory  

NASA Astrophysics Data System (ADS)

The planned underdense plasma lens experiment at the UCLA Neptune Laboratory is presented. For this experiment, a LaB_6-based discharge plasma source was developed and tested. It was proved that the plasma source can produce an argon plasma in the density range of low 10^12 cm-3. For the experiment, electron beams with an energy of 16 MeV, a charge of 4 nC, a pulse duration (FWHM) of 30 ps are generated from the 1.6-cell photocathode RF gun and PWT linac. The electron beams are designed to propagate through an underdense plasma with a few cm thickness. To predict the experimental result, computer simulations with a 2 and 1/2 dimensional particle-in-cell code (MAGIC) were performed. In this presentation, the plasma source test and simulation results are described.

Suk, H.; Clayton, C. E.; Joshi, C.; Loh, M.; Muggli, P.; Pellegrini, C.; Ritesh, N.; Rosenzweig, J. B.; Katsoules, T.

1999-11-01

188

Conductive Education and the Mediated Learning Experience Theory of Feuerstein.  

ERIC Educational Resources Information Center

|This paper examines parallels between aspects of conductive education for brain-damaged children and R. Feuerstein's theory of mediated learning. Two key aspects of Feuerstein's theory are examined and applied to conductive education: structural cognitive modifiability and the mediation process between culture and child. Mediation processes,…

Lebeer, Jo

1995-01-01

189

Long conduction time plasma erosion opening switch experiment  

Microsoft Academic Search

A plasma erosion opening switch, coupled to a small capacitor bank, conducts 120 kA for 400 ns before opening in 40 ns. Voltages above 170 kV are produced through the use of an electron beam diode. These voltages exceed the initial capacitor bank voltage by a factor of 4. Current and magnetic field measurements indicate that the same current conduction

D. D. Hinshelwood; J. R. Boller; R. J. Commisso; G. Cooperstein; R. A. Meger; J. M. Neri; P. F. Ottinger; B. V. Weber

1986-01-01

190

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

191

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

192

Laboratory experiments and modeling for industrial radiotracer applications.  

PubMed

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

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

2010-02-06

193

Experiment of electrical conductivity at low temperature (preliminary measurement)  

SciTech Connect

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

Zhao, Y.; Wang, H.

1998-07-01

194

Thermal conductivity of polycrystalline CVD diamond: Experiment and theory  

SciTech Connect

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

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

2008-09-15

195

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

196

Laboratory experiments for exploring the surface plasmon resonance  

NASA Astrophysics Data System (ADS)

The surface plasmon wave is a surface wave confined at the interface between a dielectric and a metal. The excitation of the surface plasmon resonance (SPR) on a gold thin film is discussed within the Kretschmann configuration, where the coupling with the excitation light is achieved by means of a prism in total reflection. The electromagnetic principles are detailed and a simple experimental setup is described that can be used for laboratory experiments for senior students in the third or fourth year of university. This experiment allows accurate determination of the angle of plasmon extinction and discussion of the principles of biosensors based on the SPR. A slight modification of the setup allows the investigation of the dependence of SPR on wavelength and illustrates the damping of SPR due to its coupling with the interband transitions of the gold thin film.

Pluchery, Olivier; Vayron, Romain; Van, Kha-Man

2011-03-01

197

Simulating zonation in geophysical flows by laboratory experiments  

NASA Astrophysics Data System (ADS)

The laboratory modelling of a rotating turbulent flow subjected to a ?-effect by means of laboratory experiments is considered. In particular the focus has been put on the emergence and the evolution of zonal jet-like structures due to the anisotropization of the upscale energy transfer that can be observed in geophysical flows. The experimental setup consists of a rotating tank in which a turbulent flow is reproduced by electromagnetically forcing a shallow layer of saline solution; this model then reproduces the dynamics in the polar regions simulating the so-called ?-plane by the parabolic surface of the rotating fluid. Several experiments have been performed by changing the main external parameters in order to investigate if the setup is suitable for reproducing the basic dynamics associated with a banded configuration analogous to large scale atmospheric and oceanic circulations. Velocity measurements performed by image analysis have allowed characterization of the flow in terms of mean azimuthal velocity, degree of anisotropy, distribution of energy, and characteristic scales. As expected, zonal jets have been found to dominate the dynamics when the ?-effect is stronger.

Di Nitto, G.; Espa, S.; Cenedese, A.

2013-08-01

198

Resonant solar neutrino oscillation versus laboratory neutrino oscillation experiments  

SciTech Connect

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

Lim, Chong-Sa

1987-02-01

199

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

200

Assessment of the predictive capabilities of stochastic theories in a three-dimensional laboratory test aquifer: Effective hydraulic conductivity and temporal moments of breakthrough curves  

Microsoft Academic Search

Conservative and sorptive tracer experiments were conducted in a highly heterogeneous (?lnK2 = 1.79) and anisotropic (?H\\/?V = 3.52) three-dimensional test aquifer under well-controlled laboratory conditions to evaluate the effective conductivity and temporal moments predicted by stochastic theories. The spatial distribution of lnK in the test aquifer conformed to a statistically homogeneous system, thus allowing evaluation of results from stochastic

Daniel Fernàndez-Garcia; Harihar Rajaram; Tissa H. Illangasekare

2005-01-01

201

Assessment of the predictive capabilities of stochastic theories in a three-dimensional laboratory test aquifer: Effective hydraulic conductivity and temporal moments of breakthrough curves  

Microsoft Academic Search

Conservative and sorptive tracer experiments were conducted in a highly heterogeneous (sigmalnK2 = 1.79) and anisotropic (lambdaH\\/lambdaV = 3.52) three-dimensional test aquifer under well-controlled laboratory conditions to evaluate the effective conductivity and temporal moments predicted by stochastic theories. The spatial distribution of lnK in the test aquifer conformed to a statistically homogeneous system, thus allowing evaluation of results from stochastic

Daniel Fernàndez-Garcia; Harihar Rajaram; Tissa H. Illangasekare

2005-01-01

202

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

203

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

204

Conductivity  

NSDL National Science Digital Library

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

Integrated Teaching And Learning Program

205

Using the learning cycle to develop freshmen's abilities to design and conduct experiments  

Microsoft Academic Search

A series of three laboratory experiments has been developed for first-semester freshmen mechanical engineering students at the University of South Carolina. The topical content of the experiments includes statics, solid mechanics, fluid mechanics and direct-current circuit analysis. Each experiment actively involves the students, is inexpensive, safe and can be performed during a 50- minute class period. The experiments have been

Jed S. Lyons; John S. Brader

206

Hypervelocity Impact Experiments in the Laboratory Relating to Lunar Astrobiology  

NASA Astrophysics Data System (ADS)

The results of a set of laboratory impact experiments (speeds in the range 1-5 km s-1) are reviewed. They are discussed in the context of terrestrial impact ejecta impacting the Moon and hence lunar astrobiology through using the Moon to learn about the history of life on Earth. A review of recent results indicates that survival of quite complex organic molecules can be expected in terrestrial meteorites impacting the lunar surface, but they may have undergone selective thermal processing both during ejection from the Earth and during lunar impact. Depending on the conditions of the lunar impact (speed, angle of impact etc.) the shock pressures generated can cause significant but not complete sterilisation of any microbial load on a meteorite (e.g. at a few GPa 1-0.1% of the microbial load can survive, but at 20 GPa this falls to typically 0.01-0.001%). For more sophisticated biological products such as seeds (trapped in rocks) the lunar impact speeds generate shock pressures that disrupt the seeds (experiments show this occurs at approximately 1 GPa or semi-equivalently 1 km s-1). Overall, the delivery of terrestrial material of astrobiological interest to the Moon is supported by these experiments, although its long term survival on the Moon is a separate issue not discussed here.

Burchell, M. J.; Parnell, J.; Bowden, S. A.; Crawford, I. A.

2010-12-01

207

Laboratory experiments of supersonic flows through clumpy environments  

NASA Astrophysics Data System (ADS)

Supersonic flows through heterogeneous environments are common in astrophysics as evidenced by high resolution Hubble Space Telescope images of a variety of astrophysical objects, including supernova remnants and stellar jets. In many instances, the imaged flows exhibit a complex morphology consisting of multiple clumps, bow shocks, and filamentary structure extending over a range of spatial scales. To gain a better understanding of the dynamics occurring in such multi-clump flows, scaled laboratory experiments are being carried out at the Omega Laser Facility. In these experiments, a laser pulse is used to heat a halfraum to indirectly drive a near planar shock through a target that typically consists of many small dense spheres embedded in lower density foam. The evolution of the target is then imaged using x-ray radiography. Targets have been designed to span the parameter space of clump number and clump size distribution, as well as investigate the quantitative differences in shock propagation through a clumpy target with that of a uniform target of the same average density. An overview of the experiments and comparison with simulations will be presented.

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

2010-11-01

208

Communicating pathology and laboratory errors: anatomic pathologists' and laboratory medical directors' attitudes and experiences.  

PubMed

Physicians are urged to communicate more openly following medical errors, but little is known about pathologists' attitudes about reporting errors to their institution and disclosing them to patients. We undertook a survey to characterize pathologists' and laboratory medical directors' attitudes and experience regarding the communication of errors with hospitals, treating physicians, and affected patients. We invited 260 practicing pathologists and 81 academic hospital laboratory medical directors to participate in a self-administered survey. This survey included questions regarding estimated error rates and barriers to and experience with error disclosure. The majority of respondents (~95%) reported having been involved with an error, and respondents expressed near unanimous belief that errors should be disclosed to hospitals, colleagues, and patients; however, only about 48% thought that current error reporting systems were adequate. In addition, pathologists expressed discomfort with their communication skills in regard to error disclosure. Improving error reporting systems and developing robust disclosure training could help prevent future errors, improving patient safety and trust. PMID:21502431

Dintzis, Suzanne M; Stetsenko, Galina Y; Sitlani, Colleen M; Gronowski, Ann M; Astion, Michael L; Gallagher, Thomas H

2011-05-01

209

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

NASA Astrophysics Data System (ADS)

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

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

1993-10-01

210

Exploring mechanisms of root erosion by flood in laboratory experiments  

NASA Astrophysics Data System (ADS)

Riparian vegetation developing on the bare alluvial sediment may strongly contribute to the local stabilization of river bedforms and, in turn to the resulting river morphodynamics. Both seedlings from germinated seeds or woody debris deposits that start taking roots in the gravel sediment eventually develop into vegetation patches depending on the frequency and magnitude of floods. Ultimately, the interaction between river hydrology and vegetation growth time scales depends on the anchoring mechanism of certain root type and age within the non-cohesive alluvial soil. Recently, we started to explore the mechanisms of flow erosion in the presence of vegetation roots at the laboratory scale, in order to help explaining some observations that have been made at the laboratory scale (Perucca et al., this Session) and in the field, that is a restored river reach (Pasquale et al., this Session). In this paper, we propose a conceptual mechanism showing that root erosion by floods depends on root architecture (age and structure), and that uprooting is essentially of two types. The first type is relevant to young vegetation and is mainly due to a balance between flow drag force and resistance to uprooting. The second type concerns more mature vegetation and implies that considerable localized erosion additionally takes place in order to produce uprooting. Such two processes occur at completely different time scales, being quite instantaneous the first, and rather delayed the second. Although made at laboratory scale, the results of our preliminary experiments seem to support the idea ursued by the conceptual model. Future test will aim at better unravel the details of the root erosion dynamics and at formulating a modelling theory therof, the implications of which range from ecohydrology to river restoration practice.

Edmaier, Katharina; Perona, Paolo

2010-05-01

211

A Simple Laboratory Experiment to Measure e/k  

NASA Astrophysics Data System (ADS)

The measurement of fundamental constants is common practice in instructional laboratories. A number of the equipment manufacturers have developed apparatus for such applications, e.g., the determination of e by the Millikan oil drop method or the determination of the speed of light with fiber optics. Other experiments determine not a single constant, but a combination of constants, e.g., e/m by electron beam deflection in a magnetic field or h/e by the photoelectric effect. About 30 years ago Carl E. Miller and I1 proposed a method of measuring e/k, the ratio of the electron charge to Boltzmann's constant, that was reasonably simple but not necessarily inexpensive because it involved the use of a sensitive electrometer. In recent years, however, inexpensive digital multimeters (DMM), many costing less than $30, have found their way into the physics laboratory. The purpose of this paper is to suggest the use of two DMMs, one operating as a voltmeter and the other as an ammeter, in a simple circuit involving a junction transistor and a variable potential source. Even the potential source can be quite simple, a 1.5-V battery and a 1-k? potentiometer, as shown in Fig. 1. If available, a variable dc power supply replacing the battery and potentiometer would be more convenient.

Inman, Fred

2005-01-01

212

The Nature of Laboratory Learning Experiences in Secondary Science Online  

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

213

Demonstration of auroral radio emission mechanisms by laboratory experiment  

NASA Astrophysics Data System (ADS)

Auroral kilometric radiation occurs in regions of depleted plasma density in the polar magnetosphere. These emissions are close to the electron cyclotron frequency and appear to be connected to the formation of high pitch angle electron populations due to the conservation of the magnetic moment. This results in a horseshoe type distribution function being formed in velocity space where electrons are magnetically compressed as they descend towards the Earth's atmosphere. Satellites have observed that radio emissions occur in conjunction with the formation of this distribution and show the radiation to have propagation and polarization characteristics of the extraordinary (X-mode) plasma mode with emission efficiency observed at ~1-2%. To investigate this phenomenon a laboratory experiment, scaled to microwave frequencies and lab dimensions by increasing the cyclotron frequency, was constructed whereby an electron beam propagated through a region of increasing magnetic field created by five independently variable solenoids. Results are presented for two experimental regimes of resonant coupling, 11.7 and 4.42 GHz, achieved by varying the peak magnetic field. Measurements of the experimental radiation frequency, power and efficiency were undertaken as a function of the magnetic compression. Results showed the radiation to be polarized in the near cut-off transverse electric radiation modes, with efficiency of emission ~1-2%, peak power outputs of ~19-30 kW and frequency close to the cyclotron frequency. This represented close correlation between the laboratory radiation efficiency, spectra, polarization and propagation with that of numerical predictions and the magnetospheric observations.

McConville, S. L.; Speirs, D. C.; Ronald, K.; Phelps, A. D. R.; Cross, A. W.; Bingham, R.; Robertson, C. W.; Whyte, C. G.; He, W.; Gillespie, K. M.; Vorgul, I.; Cairns, R. A.; Kellett, B. J.

2008-07-01

214

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

PubMed Central

Background Over the last decade several phase III microbicides trials have been conducted in developing countries. However, laboratories in resource constrained settings do not always have the experience, infrastructure, and the capacity to deliver laboratory data meeting the high standards of clinical trials. This paper describes the design and outcomes of a laboratory quality assurance program which was implemented during a phase III clinical trial evaluating the efficacy of the candidate microbicide Cellulose Sulfate 6% (CS) [1]. Methodology In order to assess the effectiveness of CS for HIV and STI prevention, a phase III clinical trial was conducted in 5 sites: 3 in Africa and 2 in India. The trial sponsor identified an International Central Reference Laboratory (ICRL), responsible for the design and management of a quality assurance program, which would guarantee the reliability of laboratory data. The ICRL provided advice on the tests, assessed local laboratories, organized trainings, conducted supervision visits, performed re-tests, and prepared control panels. Local laboratories were provided with control panels for HIV rapid tests and Chlamydia trachomatis/Neisseria gonorrhoeae (CT/NG) amplification technique. Aliquots from respective control panels were tested by local laboratories and were compared with results obtained at the ICRL. Results Overall, good results were observed. However, discordances between the ICRL and site laboratories were identified for HIV and CT/NG results. One particular site experienced difficulties with HIV rapid testing shortly after study initiation. At all sites, DNA contamination was identified as a cause of invalid CT/NG results. Both problems were timely detected and solved. Through immediate feedback, guidance and repeated training of laboratory staff, additional inaccuracies were prevented. Conclusions Quality control guidelines when applied in field laboratories ensured the reliability and validity of final study data. It is essential that sponsors provide adequate resources for implementation of such comprehensive technical assessment and monitoring systems. Trial Registration ClinicalTrials.gov NCT00153777 and Current Controlled Trials ISRCTN95638385

Crucitti, Tania; Fransen, Katrien; Maharaj, Rashika; Tenywa, Tom; Massinga Loembe, Marguerite; Murugavel, Kailapuri Gangatharan; Mendonca, Kevin; Abdellati, Said; Beelaert, Greet; Van Damme, Lut

2010-01-01

215

Rainfall estimation using moving cars as rain gauges - laboratory experiments  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

216

Bacterial transport in heterogeneous porous media: Observations from laboratory experiments  

NASA Astrophysics Data System (ADS)

Transport of bacteria through heterogeneous porous media was investigated in small-scale columns packed with sand and in a tank designed to allow the hydraulic conductivity to vary as a two-dimensional, lognormally distributed, second-order stationary, exponentially correlated random field. The bacteria were Pseudomonas ftuorescens R8, a strain demonstrating appreciable attachment to surfaces, and strain Ml, a transposon mutant of strain R8 with reduced attachment ability. In bench top, sand-filled columns, transport was determined by measuring intensity of fluorescence of stained cells in the effluent or by measuring radiolabeled cells that were retained in the sand columns. Results demonstrated that strain Ml was transported more efficiently than strain R8 through columns packed with either a homogeneous silica sand or a more heterogeneous sand with iron oxide coatings. Two experiments conducted in the tank involved monitoring transport of bacteria to wells via sampling from wells and sample ports in the tank. Bacterial numbers were determined by direct plate count. At the end of the first experiment, the distribution of the bacteria in the sediment was determined by destructive sampling and plating. The two experiments produced bacterial breakthrough curves that were quite similar even though the similarity between the two porous media was limited to first- and second-order statistical moments. This result appears consistent with the concept of large-scale, average behavior such as has been observed for the transport of conservative chemical tracers. The transported bacteria arrived simultaneously with a conservative chemical tracer (although at significantly lower normalized concentration than the tracer). However, the bacterial breakthrough curves showed significant late time tailing. The concentrations of bacteria attached to the sediment surfaces showed considerably more spatial variation than did the concentrations of bacteria in the fluid phase. This contrast between behavior in the fluid phase and on the solids is consistent with field observations by other authors and initial modeling of these heterogeneous media.

Silliman, S. E.; Dunlap, R.; Fletcher, M.; Schneegurt, M. A.

2001-11-01

217

Integration of laboratory and field data for insight on the multiwell experiment paludal stimulation  

SciTech Connect

Two stimulation operations have been conducted to date in the paludal zone of the Mesaverde formation in one well, MWX-1, at the DOE's Multiwell Experiment test site in the Piceance Basin near Rifle, Colorado. Problems were encountered in the second stimulation: MWX-1 would not sustain production for several months and post-frac production was less than pre-frac rates. The laboratory program was expanded to examine these problems and these laboratory studies were integrated with well testing and other data to help explain MWX-1 production behavior. A unique explanation cannot be found for the failure of MWX-1 to produce; a combination of factors was responsible. Water probably inhibited matrix rock production. A system of naturally occurring microfractures is important in production from the paludal zone and it probably sustained damage by water and fracture fluids. The basic gel degraded slowly because only a small amount of breaker was used. The fracture closure (viscosity break) observed from the Nolte analysis of the stimulation was not the same as the breakdown of the basic gel. The remedial treatment conducted after the second stimulation was probably too reactive. A list of items has been developed from experience gained both inside and outside the laboratory that shows what work and which procedures should be emphasized or avoided in tight sand stimulations. 16 references, 7 figures, 9 tables.

Sattler, A.R.; Raible, C.J.; Gall, B.L.

1985-01-01

218

Laser guide star experiment at Lawrence Livermore National Laboratory  

SciTech Connect

An overview of the Laser Guide Star feasibility experiment at Lawrence Livermore National Laboratory is presented. The goal of the project is to demonstrate a closed-loop adaptive optics system using a sodium-layer laser guide star to correct wavefront aberrations caused by atmospheric turbulence. The laser beam is projected upwards from a beam director located 5 meters from a half-meter telescope and forms a spot about 2 meters in diameter in the mesospheric sodium layer at an altitude of about 95 km. The laser beam is approximately fifth magnitude and is visible to the unaided eye at the top of the Rayleigh-scattered laser beam. A Shack-Hartmann wave front sensor measures the aberrated wave front and a continuous sheet deformable mirrow will correct the wave front in a closed loop control system at a bandwidth fast enough to follow changes in the atmosphere. In this paper, the authors present an overview of the methodology for the design of the experiment and the requirements of the laser source. The long term goal of this effort is to develop laser guide stars and adaptive optics for large astronomical telescopes and to this end, a summary of laser issues relevant to future sites is presented.

Max, C.E.; Friedman, H.W.; Brase, J.B.; Avicola, K.; Bissinger, H.; Gavel, D.T.; Horton, J.A.; Morris, J.R.; Olivier, S.S.; Presta, R.W.; Rapp, D.A.; Salmon, T.J.; Waltjen, K.

1993-01-01

219

Saline conducted electric coagulation (SCEC): original experience in experimental hepatectomy  

PubMed Central

Objective: To evaluate the feasibility and superiority of a new coagulating and hemostatic method named “saline conducted electric coagulation (SCEC)”. Methods: The Peng's multifunction operative dissector (PMOD) was modified to enable saline to effuse persistently out of its nib at a constant speed. In a group of six New Zealand rabbits, two hepatic lobes of each rabbits were resected respectively by SCEC and conventional electric coagulation (EC). The features of SCEC were recorded by photo and compared with conventional EC. After 7 d, the coagulating depth was measured in each residual hepatic lobe. Hepatic tissue was dyed by hematoxylin and eosin (HE) and studied under a microscope. Results: The coagulating depth increased with the continuation of SCEC time. Hepatectomies were performed successfully, no rabbit died in the perioperative period. The incisal surface of SCEC was gray-white with no red bleeding point. There was a thick solidified layer at the margin and a thin red-white intermittent layer between the solidified layer and normal hepatic tissue at the vertical section of SCEC. The mean coagulating depth of SCEC was 1.8 cm vs. 0.3 cm of conventional EC. Pathological examination showed a mild inflammatory reaction by SCEC. Conclusions: SCEC is a feasible and safe method for surgical hemostasis. As a new technique for liver resection, SCEC shows better coagulating effect and milder inflammatory reaction than conventional EC. Our study shows bloodless liver resection can also be performed by SCEC, especially for liver malignant tumor.

Ding, Guo-ping; Cao, Li-ping; Liu, Da-ren; Que, Ri-sheng

2012-01-01

220

NAPL Mass Reduction Effects on Contaminant Source Strength: Laboratory Experiments  

NASA Astrophysics Data System (ADS)

The longevity of sites contaminated with chlorinated solvents, and the associated implication for plume management options, has made source zone remediation an attractive option. However, source zone remediation is challenging and recent field scale demonstrations of aggressive source zone remediation have pointed to the technical infeasibility of complete restoration of the source zone. Another approach to evaluating the success of source zone remediation is in a risk-based framework, where the technology is evaluated for its ability to reduce the source strength to a level where the risk to down-gradient receptors is lowered below a certain threshold. Virtually all field and laboratory research of source zone remediation to date has focused on the technology's ability to remove mass from the source zone and has not evaluated the impact of the remediation on source strength. This prevents the analysis of previous work in a risk-based framework. In this work we evaluate relationships between mass reduction and source strength (mass flux of contaminant) in two-dimensional laboratory flow cells with heterogeneous distributions of porous media. The flow cell features a segmented extraction well which allows for segmented measurements of water and contaminant flux. The flow cell is designed to investigate the effects of NAPL morphology and distribution (source-zone architecture) in relation to a heterogeneous flow field on mass reduction/flux reduction relationships. Results indicate a linear relationship between mass reduction and flux reduction with relationships for individual well segments oscillating about a mean trend describing the entire system. Results from a series of experiments, with varying degrees of heterogeneity are presented with an emphasis on contaminant flux plane response to changes in source-zone architecture.

Fure, A. D.; Jawitz, J. W.; Annable, M. D.

2003-12-01

221

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

Code of Federal Regulations, 2013 CFR

... § 101.108 Temporary exemptions for purposes of conducting authorized food labeling experiments. (a) The food industry is encouraged to experiment voluntarily, under controlled conditions and in collaboration with the Food and...

2013-04-01

222

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

Code of Federal Regulations, 2010 CFR

... § 101.108 Temporary exemptions for purposes of conducting authorized food labeling experiments. (a) The food industry is encouraged to experiment voluntarily, under controlled conditions and in collaboration with the Food and...

2009-04-01

223

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

NASA Astrophysics Data System (ADS)

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

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

2007-04-01

224

Organic contaminant distributions in sediments, polychaetes ( Nereis virens) and American lobster ( Homarus americanus) from a laboratory food chain experiment  

Microsoft Academic Search

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 Passaic River, NJ, USA, for 70 days. These polychaetes were then fed to the American lobster, Homarus americanus, for up to 112 days.

R. J. Pruell; B. K. Taplin; D. G. McGovern; R. McKinney; S. B. Norton

2000-01-01

225

Potential for Resource Competition between Eurasian Ruffe and Yellow Perch: Growth and RNA Responses in Laboratory Experiments  

Microsoft Academic Search

The ruffe Gymnocephalus cernuus, an exotic percid from Eurasia that is now established in limited areas of the Great Lakes, is invading areas currently occupied by native yellow perch Perca flavescens. We conducted two laboratory experiments to determine whether competition for benthic macroinvertebrate food (live aquatic oligochaetes) may occur, thereby resulting in reduced growth for one or both fish species.

Aimee H. Fullerton; Gary A. Lamberti; David M. Lodge; Frederick W. Goetz

2000-01-01

226

Database dictionary for the results of groundwater tracer tests using tritiated water, conducted at the Oak Ridge National Laboratory.  

National Technical Information Service (NTIS)

In 1977, the United States Geological Survey (USGS) conducted two tracer tests at the Oak Ridge National Laboratory (ORNL) using tritiated water to study the relative importance of bedding-plane openings on shallow groundwater flow. Through a cooperative ...

B. K. Thompson D. D. Huff

1997-01-01

227

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

SciTech Connect

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

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

1994-02-01

228

Solitary electrostatic structures observed in a laboratory experiment  

NASA Astrophysics Data System (ADS)

Solitary electrostatic pulses interpreted as phase-space holes have been observed in numerous places of the magnetosphere such as the vicinity of reconnection current sheets, shocks or auroral current layers. They are thought to affect plasma resistivity and heating, and may play a role in particle acceleration. However these roles have not been fully clarified, and this is particularly so in magnetized plasmas where some of their basic properties such as their stability remain poorly understood. Here we present the first results of a series of experiments conducted at the UCLA plasma device (LAPD). Solitary waves were generated by injecting a weak electron beam into a cold (with a large beam velocity compared to thermal speeds), weakly collisional (large mean free path compared to experiment size) and magnetized background plasma. Beam energies varied from 30 to 120 eV, and magnetic fields from 75 (?pe â?« ?ce) to 750 G (?pe â?ª ?ce). A set of electric field probes separated by approximately a Debye length (~60 m) allowed us to estimate propagation characteristics and scale size of the structures. The velocity of the structures was found to be a fraction of the beam velocity and their sizes of the order of few tens of Debye lengths. A stronger magnetic field was found to be a stabilizing factor for the solitary structures.

Lefebvre, B.; Chen, Li-J.; Gekelman, W.; Kintner, P.; Pickett, J.; Pribyl, P.; Chiang, F. C.

2009-04-01

229

Frictional sliding in layered rock: laboratory-scale experiments  

SciTech Connect

The work is part of the rock mechanics effort for the Yucca Mountain Site Characterization Program. The laboratory-scale experiments are intended to provide high quality data on the mechanical behavior of jointed structures that can be used to validate complex numerical models for rock-mass behavior. Frictional sliding between simulated rock joints was studied using phase shifting moire interferometry. A model, constructed from stacks of machined and sandblasted granite plates, contained a central hole bore normal to the place so that frictional slip would be induced between the plates near the hole under compressive loading. Results show a clear evolution of slip with increasing load. Since the rock was not cycled through loading- unloading, the quantitative differences between the three data sets are probably due to a ``wearing-in`` effect. The highly variable spatial frequency of the data is probably due to the large grain size of the granite and the stochastic frictional processes. An unusual feature of the evolution of slip with increasing load is that as the load gets larger, some plates seem to return to a null position. Figs, 6 refs.

Buescher, B.J.; Perry, K.E. Jr.; Epstein, J.S.

1996-09-01

230

Microcomputer-controlled laboratory system for field potential experiments.  

PubMed

A microcomputer-controlled laboratory system for hippocampal field potential experiments was constituted. This system realized the quasi-simultaneous processing of execution of stimulation, data acquisition, data display and data analysis by means of a microcomputer for the first time. To attain this quasi-simultaneous processing, a new algorithm for drawing a tangent on the wave-form of the potential was contrived, which enabled rapid analysis of an arbitrary population spike even in the case of generation of double spikes. The system has the following functions: (1) execution of the programmed stimulation paradigm, (2) analog/digital (A/D) conversion of the evoked field potential with a sampling interval of more than 50 microseconds per channel, (3) display of the A/D converted wave-form data on a CRT and storage of the data on a floppy disk, (4) on-line analysis of the population excitatory postsynaptic potential (EPSP) and population spike, (5) more detailed off-line analysis of the field potentials, and (6) output of the wave-form data and measured values through a printer and an X-Y plotter. PMID:2770334

Ashida, H; Maru, E; Tatsuno, J

1989-08-01

231

Thermal Convection In A Heterogeneous Mantle: Insights From Laboratory Experiments  

NASA Astrophysics Data System (ADS)

Mounting evidence indicates that the Earth's mantle is chemically heterogeneous. I review the experimental studies undertaken in order to understand the forms that con- vection might take in such a mantle. Laboratory experiments prove a powerful tool to tackle this problem since they are three-dimensional and select "naturally" the phe- nomena at play in Nature. Starting from the general problem of thermochemical convection in a fluid stratified in density and viscosity, I will show how, applied to mantle convection, it can explain a number of observations on Earth such as hot spots, superswells or the survival of several reservoirs in the mantle. The scaling laws derived from the experimental data base allow now to predict a number of characteristics of those features, such as their geometry, size, time and chemical evolution. In particular, we shall see that 1) because of mixing, no "primitive" reservoir can have survived untouched up to now and 2) density heterogeneities are an efficient way to anchor plumes, and therefore to create relatively fixed hot spots.

Davaille, A.

232

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

ERIC Educational Resources Information Center

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

Hesser, Tiffany L.; Schwartz, Pauline M.

2013-01-01

233

Design of a laboratory experiment on optical fiber and applications in fiber sensors  

Microsoft Academic Search

Summary form only given. An undergraduate laboratory experiment was designed by a senior electrical engineering student. First, students learn about the physics of fibers and investigate different properties of multi-mode and single mode fibers. The second goal is to apply this knowledge to a functional fiber sensor in the laboratory. The experiment is part of the laboratory component of an

Ryan A. Sherry; Susan M. Lord

1997-01-01

234

Safety in the Chemical Laboratory: Experiments Integrating Evaluation of Chemical Hazards into the Chemistry Curriculum.  

ERIC Educational Resources Information Center

|Proposes use of two experiments to sample and analyze contaminents in the laboratory. Experiments focus on estimating hydrogen sulfide levels in the general chemistry laboratory during qualitative analysis and determining the concentration of organic vapors associated with organic chemistry laboratories. (JN)|

Pierce, J. T.; And Others

1984-01-01

235

Safety in the Chemical Laboratory: Experiments Integrating Evaluation of Chemical Hazards into the Chemistry Curriculum.  

ERIC Educational Resources Information Center

Proposes use of two experiments to sample and analyze contaminents in the laboratory. Experiments focus on estimating hydrogen sulfide levels in the general chemistry laboratory during qualitative analysis and determining the concentration of organic vapors associated with organic chemistry laboratories. (JN)

Pierce, J. T.; And Others

1984-01-01

236

Two-dimensional stable-layered laboratory-scale experiments for testing density-coupled flow models  

Microsoft Academic Search

A series of laboratory-scale two-dimensional porous medium tank experiments was conducted to study stable-layered variable density flow problems using well-defined experimental parameters and boundary conditions. The experiments were carried out both in a rectangular flow tank and in a more complex geometrical setup aimed at studying variable density flow in geometries similar to geological formations of aquifers and aquicludes connected

M. Konz; P. Ackerer; A. Younes; P. Huggenberger; E. Zechner

2009-01-01

237

Results of direct containment heating integral experiments at 1\\/40th scale at Argonne National Laboratory  

Microsoft Academic Search

A series of integral tests have been completed that investigate the effect of scale and containment atmosphere initial composition on Direct Containment Heating (DCH) phenomena at 1\\/40 linear scale. A portion of these experiments were performed as counterparts to integral experiments conducted at 1\\/10th linear scale at Sandia National Laboratories. The tests investigated DCH phenomena in a 1\\/40th scale mockup

J. L. Binder; L. M. McUmber; B. W. Spencer

1993-01-01

238

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.

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

1972-01-01

239

A heating experiment in the argillites in the Meuse/Haute-Marne underground research laboratory  

SciTech Connect

A heating experiment named TER is being conducted with the objectives to identify the thermal properties, as well as to enhance the knowledge on THM processes in the Callovo-Oxfordian clay at the Meuse/Haute Marne Underground Research Laboratory (France). The in situ experiment has being switched on from early 2006. The heater, 3 m length, is designed to inject the power in the undisturbed zone at 6 m from the gallery wall. A heater packer is inflated in a metallic tubing. During the experiment, numerous sensors are emplaced in the surrounding rock and are experienced to monitor the evolution in temperature, pore-water pressure and deformation. The models and numerical codes applied should be validated by comparing the modeling results with the measurements. In parallel, some lab testing have been achieved in order to compare the results given with two different scales (cm up to meter scale). In this paper, we present a general description of the TER experiment with installation of the heater equipment and the surrounding instrumentation. Details of the in situ measurements of temperature, pore-pressure and strain evolutions are given for the several heating and cooling phases. The thermal conductivity and some predominant parameters in THM processes (as linear thermal expansion coefficient and permeability) will be discussed. (authors)

Wileveau, Yannick; Su, Kun [Agence Nationale pour la gestion des dechets radioactifs - ANDRA (France); Ghoreychi, Mehdi [Institut National de l'Environnement industriel et des risques - INERIS (France)

2007-07-01

240

Design and instrumentation of in situ experiments in underground laboratories for radioactive waste disposal  

Microsoft Academic Search

This book provides a review of current development and includes contributions on experiences gained at the Asse mine, Germany (in salt); the Stripa mine, Sweden (in granite); the Underground Research Laboratory at Pinawa, Canada (in granite); and the Mol excavations (in Belgium clay). It also includes the following contributions: experience and objectives of underground laboratories; review of experiments in the

B. Come; P. Johnston; A. Muller

1985-01-01

241

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

242

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

243

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

244

A new laboratory instrument for defining near-saturation wetting-drying and capillary conductivity  

NASA Astrophysics Data System (ADS)

The moisture release curve is a fundamental descriptor of soil water movement. While tension table apparatus for defining drainage curves in the near-saturated region (0 to -100 cm H2O) have been available for many decades, there has been little advance in automating the process, particularly when measurements of wetting, drying and capillary conductivity are combined. We describe a new instrument, the Automated Moisture Release Apparatus (AMRA), that uses a precision water flow measurement coupled with an accurately controlled variable hydraulic head to exactly define the relationship between matric potential and volumetric water content? from 0 to -100 cm H2O. The new instrument automates the process without any disturbance to the soil core and and has fully programmable suction steps and equilibration times. We compare AMRA moisture release curve results with published Accusand tests for four different grain size mixtures and under different sample height and volume combinations. Our results are consistent with published results and our tests provide guidance on appropriate core lengths for media characterization. AMRA results from field samples from well-characterized soils at the HJ Andrews Experimental Forest in Oregon are also described. These experiments show both consistent drying behavior and drainable porosity decline with depth in the vadose zone. Overall, the instrument's precision, programmable platform, and combined conductivity and moisture content measurement features, make it a useful tool for estimating soil water storage properties/parameters for use in vadose zone hydrology.

Vache, K.; McDonnell, J. J.; Ekanayake, J.; Graham, C.

2004-12-01

245

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

246

Disposal of Brine by Solar Evaporation: Laboratory Experiments.  

National Technical Information Service (NTIS)

The investigation reported describes laboratory studies of the effect of salinity, effect of dyes, and design models on solar evaporation of brine. Naphthol Green dye was determined to increase the absorptivity of radiation the greatest of all dyes tested...

C. Morales C. G. Keyes D. C. Winans H. R. Pritchett W. S. Gregory

1970-01-01

247

Kinetic Analysis of Metal Ions: An Undergraduate Laboratory Experiment.  

ERIC Educational Resources Information Center

Reports on the adaptation of a kinetic method of analysis of metal ions for use in an undergraduate teaching laboratory. Background information, procedures used, and analysis of typical results obtained are provided. (JN)

Williams, Kathryn R.

1985-01-01

248

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

PubMed

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

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

2013-07-02

249

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

250

Hands-On Laboratory Experience via Remote Control: Jet Thrust Laboratory  

Microsoft Academic Search

This paper describes the development of a remote-controlled jet thrust laboratory for illustrating the fundamentals of compressible fluid mechanics as part of an undergraduate mechanical engineering curriculum. The laboratory is the first in a series to be developed jointly by faculty at Rutgers University and the University of Illinois at Urbana-Champagne. The sharing of resources significantly reduces the per institution

Madara Ogot; Gregory Elliott; Nick Glumac

2002-01-01

251

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.

252

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

National Technical Information Service (NTIS)

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...

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

1994-01-01

253

Laboratory Experiments of Sand Ripples with Bimodal Size Distributions Under Asymmetric Oscillatory Flows  

NASA Astrophysics Data System (ADS)

The dynamics of sand ripples are vital to understanding numerous coastal processes such as sediment transport, wave attenuation, boundary layer development, and seafloor acoustic properties. Though significant laboratory research has been conducted to elucidate oscillatory flow morphodynamics under various constant and transient forcing conditions, the majority of the previous experiments were conducted only for beds with unimodal size distributions of sediment. Recent oscillatory flow experiments as well as past laboratory observations in uniform flows suggest that the presence of heterogeneous size sand compositions may significantly impact ripple morphology, resulting in a variety of observable effects (e.g., sediment sorting, bed armoring, and altered transport rates). Experimental work was conducted in a small oscillatory flow tunnel at the Sediment Dynamics Laboratory at the Naval Research Laboratory, Stennis Space Center. Three different monochromatic oscillatory forcings having velocity asymmetry were used to study sand ripple dynamics over five bimodal and two unimodal sediment beds. The seven different mixtures were composed using two unimodal sands of different colors (blue/white) and median grain diameters (d=0.31 mm / d=0.65 mm) combined into various mixtures by mass (i.e., 0/100; 10/90; 25/75; 50/50; 75/25; 90/10; and 100/0 which denotes mass percentage of blue/white sand, respectively, within each mixture). High-definition video of the sediment bed profile was acquired in conjunction with sediment trap measurements to resolve differences in ripple geometries, migration and evolution rates due to the different sediment mixtures and flow conditions. Observational findings clearly illustrate sediment stratification within ripple crests and the depth of the active mixing layer in addition to supporting sediment sorting in previous research on symmetric oscillatory flows in which the larger grains collect on top of ripple crests and smaller grains in the troughs. Preliminary quantitative results illuminate variations in equilibrium ripple geometry, ripple migration rates, and transition time scales between equilibrium states, all as functions of the sediment size mixture and flow forcing.

Calantoni, J.; Landry, B. J.

2010-12-01

254

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

255

Planning and Conducting an International Seismic Data Exchange Experiment at the Center for Seismic Studies.  

National Technical Information Service (NTIS)

This report covers preparations for and the conduct of an international seismic data exchange experiment sponsored by the Group of Scientific Experts, U.N. Conference on Disarmament. Seismic data reports from 37 countries were transmitted over circuits of...

C. Romney L. Huszar G. A. Frazier A. Campanella M. A. Tiberio

1986-01-01

256

Data analysis of Einstein-Podolsky-Rosen-Bohm laboratory experiments  

NASA Astrophysics Data System (ADS)

Data sets produced by three different Einstein-Podolsky-Rosen-Bohm (EPRB) experiments are tested against the hypothesis that the statistics of this data is described by quantum theory. Although these experiments generate data that violate Bell inequalities for suitable choices of the time-coincidence window, the analysis shows that it is highly unlikely that these data sets are compatible with the quantum theoretical description of the EPRB experiment, suggesting that the popular statements that EPRB experiments agree with quantum theory lack a solid scientific basis and that more precise experiments are called for.

De Raedt, H.; Jin, F.; Michielsen, K.

2013-10-01

257

General Chemistry Laboratory--Scientific Inquiry: 157 New Experiments in One Semester  

NASA Astrophysics Data System (ADS)

700 General Chemistry students were allowed to choose and run their own experiment. They went to the library to select an experiment from the literature, then they modified the experiment and performed it in the laboratory. Given the appropriate guidelines, the students were able to experience chemical research and thus get an idea of what science is really all about. The success of this laboratory is discussed from both the students' and staff's perspectives.

Black, Suzanne L.

1996-08-01

258

Experiments in the Classroom: Examples of Inductive Lear ning with Classr oom-Friendly Laboratory Kits  

Microsoft Academic Search

The educational literature is full of examples of the effectiveness of inductive and hands on learning. Laboratory experiments are clearly an excellent place to encourage this type of learning. However, it would be beneficial to mix laboratory material with classroom presentations and problem solving in a more flexible approach than a traditional separate laboratory and lecture allows. We have recently

S. Scott Moor; Polly Piergiovanni

259

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

NASA Astrophysics Data System (ADS)

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

Andres, Magdalena; Cenedese, Claudia

2013-02-01

260

The Need Of Laboratory Experiments In Parallel To Astrobiological Space Fligth Experiments  

NASA Astrophysics Data System (ADS)

For laboratory studies on the responses of resistant life forms to simulated interplane- tary space conditions, test beds are available that simulate the parameters of space, such as vacuum, solar electromagnetic and cosmic ionizing radiation, temperature extremes and reduced gravity, which can be applied separately or in selected com- binations. Appropriate biological test systems are extremophiles, i.e. microorganisms that are adapted to grow or survive in extreme conditions of our biosphere. Examples are airborne microbes, endolithic or endoevaporitic microbial communities, or isolated biomolecules. The studies contribute to answer several questions of astrobiology, such as (i) the role of solar UV radiation in genetic stability, (ii) the role of gravity in basic biological functions, (iii) the chances and limits for interplanetary transfer of life, (iv) strategies of adaptation to environmental extremes, and (v) the needs for planetary protection. As an example, the ground controls that were performed in parallel with 3 BIOPAN flight experiments will be presented.

Horneck, G.

261

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

USGS Publications Warehouse

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

Perkins, Kim S.; Winfield, Kari A.

2007-01-01

262

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

263

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

264

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

265

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

266

The development of slabs in the upper mantle: Insights from numerical and laboratory experiments  

Microsoft Academic Search

We have performed numerical and laboratory experiments to model subduction of oceanic lithosphere in the upper mantle from its beginnings as a gravitational instability to the fully developed slab. A two-dimensional finite element code is applied to model Newtonian creep in the numerical experiments. Scaled analog media are used in the laboratory, a sand mixture models the brittle crust, silicone

Thorsten W. Becker; Caludio Faccenna; Richard J. O'Connell; Domenico Giardini

1999-01-01

267

EXPERIMENTS ON BUOYANT PLUME DISPERSION IN A LABORATORY CONVENTION TANK  

EPA Science Inventory

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

268

Students' Experience in a General Chemistry Cooperative Problem Based Laboratory  

ERIC Educational Resources Information Center

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

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

2011-01-01

269

Creatine Synthesis: An Undergraduate Organic Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

Students in introductory chemistry classes typically appreciate seeing the connection between course content and the "real world". For this reason, we have developed a synthesis of creatine monohydrate--a popular supplement used in sports requiring short bursts of energy--for introductory organic chemistry laboratory courses. Creatine monohydrate…

Smith, Andri L.; Tan, Paula

2006-01-01

270

Ground-based laboratory atomic oxygen calibration experiments  

Microsoft Academic Search

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

Jeremy Stephen Matcham

1998-01-01

271

Restructuring a General Microbiology Laboratory into an Investigative Experience.  

ERIC Educational Resources Information Center

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

Deutch, Charles E.

1994-01-01

272

Creatine Synthesis: An Undergraduate Organic Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

|Students in introductory chemistry classes typically appreciate seeing the connection between course content and the "real world". For this reason, we have developed a synthesis of creatine monohydrate--a popular supplement used in sports requiring short bursts of energy--for introductory organic chemistry laboratory courses. Creatine monohydrate…

Smith, Andri L.; Tan, Paula

2006-01-01

273

Active seismic monitoring of hydraulic fractures in laboratory experiments  

Microsoft Academic Search

In scaled laboratory tests, we perform acoustic measurements in a time-lapse sequence to separate the fracture response from the background signal. Using both compressional and shear waves (that are very sensitive to fluid filled fractures) we can, not only detect the hydraulic fracture, but also characterize its shape and geometry during its growth. We show the application of the technique

C. J. de Pater; J. Groenenboom; D. B. van Dam; R. Romijn

2001-01-01

274

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

Microsoft Academic Search

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

Jeffrey I. Everitt; Paul M. D. Foster

2004-01-01

275

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

276

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

277

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

278

Dispersant Effectiveness Experiments Conducted on Alaskan and Canadian Crude Oils in Very Cold Water  

Microsoft Academic Search

Dispersant effectiveness (DE) experiments were conducted to determine the effectiveness of using two chemical dispersa nts, Corexit 9500 and Corexit 9527, applied to fresh and weathered Alaskan and Canadian crude oils in very cold water. The primary goal of the experiments was to demonstrate that dispersants could be a viable countermeasure on these crude oils in cold weather conditions. Two

Joseph V. Mullin

279

LC Card Order Experiment Conducted at University of Utah Marriott Library  

ERIC Educational Resources Information Center

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

Cluff, E. Dale; Anderson, Karen

1973-01-01

280

Long term experience with semi-conductive glaze high voltage post insulators  

SciTech Connect

Insulators using semi-conductive glaze have long been known for their superior contamination performance. Early glazes for this type however were not stable and successful use of semi-conductive glazed porcelain insulators was delayed many years until tin-antimony oxide glazes were developed. Service experience of eighteen years is now available for line and station post insulators with this type of glaze. Based on this experience, the aging characteristics of tin-antimony oxide semi-conductive glazes are described and quantified. Several different applications of these insulators are also described.

Baker, A.C.; Maney, J.W.; Szilagyi, Z. (Lapp Insulator Co., LeRoy, NY (US))

1990-01-01

281

The scope for improving the design of laboratory animal experiments  

Microsoft Academic Search

Summary The factors which need to be taken into account in designing a 'good' experiment are reviewed. Such an experiment should be unbiased, have high precision, a wide range of applicability, it should be simple, and there should be a means of quantifying uncertainty (Cox 1958). The relative precision due to the use of randomized block designs was found to

Michael F. W. Festing

1992-01-01

282

Reactions of Thiocyanate Ions with Acid: A Laboratory Experiment.  

ERIC Educational Resources Information Center

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

Glidewell, Christopher; And Others

1984-01-01

283

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…

Glidewell, Christopher; And Others

1985-01-01

284

A Cyclic Voltammetry Experiment for the Instrumental Analysis Laboratory.  

ERIC Educational Resources Information Center

Background information and procedures are provided for experiments that illustrate the nature of cyclic voltammetry and its application in the characterization of organic electrode processes. The experiments also demonstrate the concepts of electrochemical reversibility and diffusion-controlled mass transfer. (JN)

Baldwin, Richard P.; And Others

1984-01-01

285

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

286

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

287

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

288

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

289

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

290

Laser-driven ICF experiments: Laboratory Report No. 223  

SciTech Connect

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

McCrory, R.L.

1991-04-01

291

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

292

Rapid slewing of the orbiting spacecraft control laboratory experiment (SCOLE) using LQR techniques  

NASA Astrophysics Data System (ADS)

The rotational equations of motion, describing the dynamics of the (rigidized) proposed orbiting Spacecraft Control Laboratory Experiment during the station-keeping phase, are derived using the Eulerian formulation. When the attitude angles (roll, pitch, and yaw) are assumed small, a stability analysis is conducted for the system. It is seen that the pitch equation decouples from the roll and yaw equations when the interface between the mast on the reflector is not offset or the offset is only along the Shuttle roll axis. When a second offset is introduced along the pitch axis of the system and when the gravity-gradient torques are present in the dynamics, the system assumes a new equilibrium position. The linear regulator theory is used to derive a control law for the linear model of the rigidized SCOLE. This law is applied to the nonlinear model of the same configuration of the system and preliminary single axis slewing maneuvers (20° amplitude) are simulated.

Diarra, Cheick M.; Bainum, Peter M.

293

Steady-State Hydraulic Tomography in a Laboratory Aquifer with Deterministic Heterogeneity: Multiscale Validation of Hydraulic Conductivity Tomograms  

Microsoft Academic Search

Hydraulic tomography is a technology that facilitates subsurface imaging of hydraulic heterogeneity through the inversion of multiple pumping test data. To date, a comprehensive validation of the hydraulic tomography has not been done either at the laboratory or field scales. Validation of hydraulic conductivity tomograms is possible using synthetic simulations because the forcing functions (initial and boundary conditions; source\\/sink terms)

W. A. Illman; X. Liu; A. J. Craig

2005-01-01

294

Database dictionary for the results of groundwater tracer tests using tritiated water, conducted at the Oak Ridge National Laboratory  

Microsoft Academic Search

In 1977, the United States Geological Survey (USGS) conducted two tracer tests at the Oak Ridge National Laboratory (ORNL) using tritiated water to study the relative importance of bedding-plane openings on shallow groundwater flow. Through a cooperative agreement between the USGS and the US Department of Energy (DOE), the data were made available to researchers at the Oak Ridge National

B. K. Thompson; D. D. Huff

1997-01-01

295

Touring the Tomato: A Suite of Chemistry Laboratory Experiments.  

PubMed

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

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

2012-12-14

296

Crop yield and light\\/energy efficiency in a closed ecological system: Laboratory Biosphere experiments with wheat and sweet potato  

Microsoft Academic Search

Two crop growth experiments in the soil-based closed ecological facility, Laboratory Biosphere, were conducted from 2003 to 2004 with candidate space life support crops. Apogee wheat (Utah State University variety) was grown, planted at two densities, 400 and 800seedsm?2. The lighting regime for the wheat crop was 16h of light – 8h dark at a total light intensity of around

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

2005-01-01

297

Hydraulic stimulation of a deep sandstone reservoir to develop an Enhanced Geothermal System: Laboratory and field experiments  

Microsoft Academic Search

The geothermal research well GtGrSk4\\/05 at Groß Schönebeck, Germany, was hydraulically stimulated to develop an Enhanced Geothermal System in the Upper Rotliegend sandstones. Gel–proppant stimulation was selected to enhance reservoir productivity and to maintain it over the long term. Before the field tests, laboratory experiments were carried out to study embedding effects and long-term hydraulic conductivity changes in intermediate- and

Günter Zimmermann; Andreas Reinicke

2010-01-01

298

Dose reconstruction for weapons experiments involving ¹⁴°La at Los Alamos National Laboratory, 1944-1962  

Microsoft Academic Search

A series of 254 weapons design experiments was conducted by Los Alamos National Laboratory from 1944 through 1962 and resulted in the dispersal of approximately 11 PBq (300 kCi) of radioactive ¹⁴°La. All shots occurred at Point Able in Bayo Canyon, east of the Los Alamos townsite. Public interest and the Government Accounting Office probe precipitated a dose reconstruction to

David H. Kraig

1997-01-01

299

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

300

Methane fluxes following slurry applications to grassland soils: laboratory experiments  

Microsoft Academic Search

The effect of soil and slurry type on methane (CH4) emissions were investigated under laboratory conditions. CH4 emissions were influenced by soil type only when the slurries applied had low dry matter contents.Pig and dairy slurries were applied at 25 m3 ha?1 to intact soil cores of a sandy loam and a silty clay. CH4 emissions were immediate from all

D. R. Chadwick; B. F. Pain

1997-01-01

301

Health information and substitution between fish: Lessons from laboratory and field experiments  

Microsoft Academic Search

This paper compares results from a lab experiment and a field experiment conducted in France to evaluate the impact of health information on fish consumption. In both experiments, health information concerns a benefit (omega 3) and a risk (methylmercury). While the lab experiment focuses on two species, namely canned tuna and canned sardines, the field experiment offers a complete measure

Stéphan Marette; Jutta Roosen; Sandrine Blanchemanche

2008-01-01

302

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

ERIC Educational Resources Information Center

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

Berkovic, G.

1984-01-01

303

The Semipermeability of Biological Membranes: An Undergraduate Laboratory Experiment.  

ERIC Educational Resources Information Center

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

Frimer, Aryeh A.

1985-01-01

304

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

305

Hazardous and Mixed Waste Solidification Development Conducted at the Idaho National Engineering Laboratory.  

National Technical Information Service (NTIS)

EG and G Idaho, Inc., has initiated a program to develop safe, efficient, cost-effective solidification treatment methods for the disposal of some of the hazardous and mixed wastes generated at the Idaho National Engineering Laboratory (INEL). Testing has...

A. M. Boehmer M. M. Larsen

1986-01-01

306

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

Code of Federal Regulations, 2012 CFR

...40.89 What is validity testing, and are laboratories required... (a) Specimen validity testing is the evaluation of the specimen...it is consistent with normal human urine. The purpose of validity testing is to determine whether...

2012-10-01

307

Astrophysical Jets Treated as Experiment in the Cyber Space Laboratory  

Microsoft Academic Search

Cyber space experiment, utilizing a combined system of fast computer plus 3D visualization system proves to be a powerful approach especially in non-linear astrophysical magnetohydrodynamic problems, among others. This is because (a) problems in extreme situations in astronomy, with which the active experiment was thus-far impossible, can now be taken into the experimental set up in the Cyber space, and

Y. Uchida; S. Hirose; M. Nakamura; T. Miyagoshi; S. Uemura; T. Kobayashi

2000-01-01

308

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

ERIC Educational Resources Information Center

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

McComas, William

2005-01-01

309

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

310

A teaching intervention for reading laboratory experiments in college-level introductory chemistry  

NASA Astrophysics Data System (ADS)

The purpose of this study was to determine the effects that a pre-laboratory guide, conceptualized as a "scientific story grammar," has on college chemistry students' learning when they read an introductory chemistry laboratory manual and perform the experiments in the chemistry laboratory. The participants (N = 56) were students enrolled in four existing general chemistry laboratory sections taught by two instructors at a women's liberal arts college. The pre-laboratory guide consisted of eight questions about the experiment, including the purpose, chemical species, variables, chemical method, procedure, and hypothesis. The effects of the intervention were compared with those of the traditional pre-laboratory assignment for the eight chemistry experiments. Measures included quizzes, tests, chemistry achievement test, science process skills test, laboratory reports, laboratory average, and semester grade. The covariates were mathematical aptitude and prior knowledge of chemistry and science processes, on which the groups differed significantly. The study captured students' perceptions of their experience in general chemistry through a survey and interviews with eight students. The only significant differences in the treatment group's performance were in some subscores on lecture items and laboratory items on the quizzes. An apparent induction period was noted, in that significant measures occurred in mid-semester. Voluntary study with the pre-laboratory guide by control students precluded significant differences on measures given later in the semester. The groups' responses to the survey were similar. Significant instructor effects on three survey items were corroborated by the interviews. The researcher's students were more positive about their pre-laboratory tasks, enjoyed the laboratory sessions more, and were more confident about doing chemistry experiments than the laboratory instructor's groups due to differences in scaffolding by the instructors.

Kirk, Maria Kristine

311

Effect of Bacillus subtilis on Granite Weathering: A Laboratory Experiment  

NASA Astrophysics Data System (ADS)

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

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

2006-12-01

312

Laboratory Experiment of Plasma Flow Around Magnetic Sail  

NASA Astrophysics Data System (ADS)

To propel a spacecraft in the direction leaving the Sun, a magnetic sail (MagSail) blocks the hypersonic solar wind plasma flow by an artificial magnetic field. In order to simulate the interaction between the solar wind and the artificially deployed magnetic field produced around a magnetic sail spacecraft, a laboratory simulator was designed and constructed inside a space chamber. As a solar wind simulator, a high-power magnetoplasmadynamic arcjet is operated in a quasisteady mode of 0.8 ms duration. It can generate a simulated solar wind that is a high-speed (above 20 km/s), high-density (1018 m-3) hydrogen plasma plume of ˜0.7 m in diameter. A small coil (2 cm in diameter), which is to simulate a magnetic sail spacecraft and can obtain 1.9-T magnetic field strength at its center, was immersed inside the simulated solar wind. Using these devices, the formation of a magnetic cavity (˜8 cm in radius) was observed around the coil, which indicates successful simulation of the plasma flow of a MagSail in the laboratory.

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

2007-01-01

313

Simulation of laboratory rip current experiments using nearshore POM  

NASA Astrophysics Data System (ADS)

A hydrostatic primitive equation model, the Princeton Ocean Model (POM), has been adapted for studies of three-dimensional wave-averaged circulation in the nearshore surf zone. The model is applied here to studies of the generation and instablilities of rip currents forced by waves normal to a beach with an alongshore bar interrupted by rip channels. The rip-current system modeled is that generated in the Directional Wave Basin located in the Ocean Engineering Laboratory at the University of Delaware. POM has been modified for application to nearshore flows by incorporating forcing from gradients in the radiation stress tensor and by including the effects of wave-induced mass flux through appropriate boundary conditions on the vertical velocity at the surface. The wave-driver REF/DIF (Kirby and Dalrymple, 1983) has been embedded as a subroutine of nearshore POM so that modification of the forcing by wave-current interaction can be included. The model results are compared with laboratory measurements of currents and surface elevation (Haller and Dalrymple, 1999; Haas and Svendsen, 2002). Instantaneous and time-mean momentum balances of both the three-dimensional and depth-averaged flows are calculated. Emphasis is placed on the variations of the currents with depth. The sensitivity of the rip current system to changes in the strength of the forcing and to details of the topography is examined.

Newberger, P. A.; Allen, J. S.

2002-12-01

314

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

PubMed

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

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

2012-06-23

315

Conducting market research using the Internet: the case of Xenon Laboratories  

Microsoft Academic Search

The way market research is conducted has changed dramatically over the past 30 years, as a result of both the development of the prevailing view of best practice and the state of technology available to researchers. While it is clear that the World Wide Web (WWW) will increasingly be used as a medium for conducting market research, the full implications

Andy Lockett; Ian Blackman

2004-01-01

316

Laboratory-scale uranium RF plasma confinement experiments  

Microsoft Academic Search

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:

W. C. Roman

1976-01-01

317

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

ERIC Educational Resources Information Center

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

Sianoudis, I. A.; Drakaki, E.

2008-01-01

318

Coulometric Analysis Experiment for the Undergraduate Chemistry Laboratory  

ERIC Educational Resources Information Center

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

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

2011-01-01

319

Experimenting in a Constructivist High School Physics Laboratory  

NSDL National Science Digital Library

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

Roth, Wolff-Michael

2006-10-09

320

Ion Exchange Chromatography and Spectrophotometry: An Introductory Undergraduate Laboratory Experiment.  

ERIC Educational Resources Information Center

Describes an experiment in which students use ion exchange chromatography to separate a mixture of chloro complexes of transition metal ions and then use spectrophotometry to define qualitatively the efficiency of the ion exchange columns. Background information, materials needed, and procedures used are included. (JN)

Foster, N.; And Others

1985-01-01

321

User Experience in Digital Games: Differences between Laboratory and Home  

ERIC Educational Resources Information Center

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

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

2011-01-01

322

A Laboratory Experiment on How to Create Dimensionless Correlations  

ERIC Educational Resources Information Center

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

Edwards, Robert V.

2010-01-01

323

Neutrino-oscillation experiments at Brookhaven National Laboratory  

SciTech Connect

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

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

1983-01-01

324

Parity violation experiments at Jefferson Laboratory: HAPPEX and G0  

SciTech Connect

A short history of parity violation is given, leading to the present use of parity violating electron scattering for studying the nucleon internal structure. The status of the G0 and HAPPEX experiments presently running at Jefferson Lab is discussed. Some preliminary results are shown.

Jacques Arvieux

2005-07-01

325

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

326

Beauty, gender and stereotypes: Evidence from laboratory experiments  

Microsoft Academic Search

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

James Andreoni; Ragan Petrie

2008-01-01

327

A low cost linear induction motor for laboratory experiments  

Microsoft Academic Search

In this paper we present a linear induction motor (LIM) prototype for education. LIMs allow easy identification and study of the different concepts and parameters of the electromagnetic circuit that they have in common with other types of electrical machine. Some experiments are presented that highlight the proposed approach. There is a wide bibliography for the diVerent applications of linear

J. Atencia; A. Garcia Rico; J. Florez

328

Molecular Velocity Determination through Gas Effusion: Intermediate Laboratory Experiment  

Microsoft Academic Search

An experiment is described to determine the average velocity of gas molecules in a container while effusion takes place through a small hole into vacuum. When the mean free path of the molecules becomes large compared to the hole diameter, the measurement of pressure as a function of time permits the average velocity to be extracted. The equipment and procedure

R. E. Benenson

1969-01-01

329

Radiative transfer theory verified by controlled laboratory experiments.  

PubMed

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. PMID:24104804

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

2013-09-15

330

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

NASA Astrophysics Data System (ADS)

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

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

2009-04-01

331

Destruction and formation of a conductive carbon nanotube network in polymer melts: In-line experiments  

Microsoft Academic Search

Investigations on electric conductivity and dielectric permittivity have been performed during melt processing of polycarbonate (PC) and polyamide 6 (PA6) containing different amounts of multi-walled carbon nanotubes (MWNT). For the experiments a measurement slit die containing two electrodes in capacitor geometry was flanged to the outlet of a twin-screw extruder. AC conductivity and the related complex permittivity were measured in

Ingo Alig; Dirk Lellinger; Martin Engel; Tetyana Skipa; Petra Pötschke

2008-01-01

332

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

Microsoft Academic Search

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

Kimberly A. Barchard; John Williams

2008-01-01

333

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

334

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

Microsoft Academic Search

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

S. Nornes; Y. Z. Tu

1989-01-01

335

Laboratory-scale experiments to determine explosive properties using spherical concentric composite explosives  

NASA Astrophysics Data System (ADS)

Laboratory-scale air-blast experiments using gram-range composite explosive charges are presented. Composite charges consist of a spherical booster charge surrounded by a concentric spherical ``candidate material'' charge in the form of a shell. Air-blast explosive tests are conducted to measure the radius vs. time of the explosively-driven shock wave using digital high-speed shadowgraphy. Profiles of peak shock wave pressure vs. radius are then found using the Rankine-Hugoniot relationship for both the booster alone and the composite charges. Using calculated peak shock wave pressures, a procedure is developed to remove the booster effects from the signature produced by the composite charge, yielding the peak shock wave pressure effect due to the candidate explosive material alone. By this means we demonstrate the ability to properly characterize, at the laboratory scale with a few grams of explosive, insensitive explosive materials that require a booster charge for detonation. This characterization yields TNT equivalence and other useful explosive properties.

Biss, Matthew; Settles, Gary

2009-11-01

336

Experimenting with spirituality: analyzing The God Gene in a nonmajors laboratory course.  

PubMed

References linking genes to complex human traits, such as personality type or disease susceptibility, abound in the news media and popular culture. In his book The God Gene: How Faith is Hardwired into Our Genes, Dean Hamer argues that a variation in the VMAT2 gene plays a role in one's openness to spiritual experiences. In a nonmajors class, we read and discussed The God Gene and conducted on a small scale an extension of the study it describes. Students used polymerase chain reaction to replicate a portion of their VMAT2 genes, and they analyzed three polymorphic sites in the sequence of these products. Associations between particular VMAT2 alleles and scores on a personality test were assessed by t test. The course, of which this project was a major part, stimulated student learning; scores on a test covering basic genetic concepts, causation/correlation, and laboratory methodology improved after completion of the course. In a survey, students reported the laboratory project aided their learning, especially in the areas of statistics and the linking of genes to behaviors. They reported high levels of engagement with the project, citing in particular its personal nature as motivating their interest. PMID:18316816

Silveira, Linda A

2008-01-01

337

Experimenting with Spirituality: Analyzing The God Gene in a Nonmajors Laboratory Course  

PubMed Central

References linking genes to complex human traits, such as personality type or disease susceptibility, abound in the news media and popular culture. In his book The God Gene: How Faith is Hardwired into Our Genes, Dean Hamer argues that a variation in the VMAT2 gene plays a role in one's openness to spiritual experiences. In a nonmajors class, we read and discussed The God Gene and conducted on a small scale an extension of the study it describes. Students used polymerase chain reaction to replicate a portion of their VMAT2 genes, and they analyzed three polymorphic sites in the sequence of these products. Associations between particular VMAT2 alleles and scores on a personality test were assessed by t test. The course, of which this project was a major part, stimulated student learning; scores on a test covering basic genetic concepts, causation/correlation, and laboratory methodology improved after completion of the course. In a survey, students reported the laboratory project aided their learning, especially in the areas of statistics and the linking of genes to behaviors. They reported high levels of engagement with the project, citing in particular its personal nature as motivating their interest.

2008-01-01

338

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

EPA Science Inventory

The results of a l6-month field and l6-month meso-scale laboratory investigation of unconsolidated sandy environments contaminated by petroleum hydrocarbons that are undergoing natural biodegradation is presented. The purpose was to understand the processes responsible for causin...

339

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

340

Astrophysical Jets Treated as Experiment in the Cyber Space Laboratory  

NASA Astrophysics Data System (ADS)

Cyber space experiment, utilizing a combined system of fast computer plus 3D visualization system proves to be a powerful approach especially in non-linear astrophysical magnetohydrodynamic problems, among others. This is because (a) problems in extreme situations in astronomy, with which the active experiment was thus-far impossible, can now be taken into the experimental set up in the Cyber space, and some active experiments can be made, (b) experimental approach is useful for non-linear problems that develop often beyond human expectations, (c) the present day computer simulation technique can deal with non-linear equation systems to a satisfactory level, and (d) the results of simulations in 3D require analyses using good 3D visualization tools. We have treated some of the problems of astronomical magnetohydrodynamics which gives the basis for active phenomena like flares and jets that have been revealed by radio and X-ray astronomy. We here discuss the astrophysical jet problem as an example.

Uchida, Y.; Hirose, S.; Nakamura, M.; Miyagoshi, T.; Uemura, S.; Kobayashi, T.

341

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

342

Planning and conducting an international seismic data exchange experiment at the center for seismic studies  

NASA Astrophysics Data System (ADS)

This report covers preparations for and the conduct of an international seismic data exchange experiment sponsored by the Group of Scientific Experts, U.N. Conference on Disarmament. Seismic data reports from 37 countries were transmitted over circuits of the WMO/GTS. The data were analyzed at centers in Washington, Moscow and Stockholm and epicenter lists were broadcast to participants. The experiment tested a number of aspects of a proposed nuclear test monitoring system.

Romney, C.; Huszar, L.; Frazier, G. A.; Campanella, A.; Tiberio, M. A.

1986-01-01

343

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

344

Floor-supply displacement air-conditioning: Laboratory experiments  

SciTech Connect

The results of laboratory measurements on the performance of a floor-supply displacement air-conditioning system in comparison to a displacement ventilation system with a side-wall-mounted diffuser and a ceiling-based distribution system are described. Thermal stratification was observed, as there were greater vertical air temperature differences in both of the displacement systems than in the ceiling-based system. The floor-supply displacement air-conditioning system produced a uniformly low air velocity at each measurement height, while a rather high air velocity near the floor was observed for the displacement ventilation system with a sidewall-mounted diffuser. Local mean age of air of the floor-supply displacement air-conditioning system was lower than that of the other systems, especially in the lower part of the room. According to the simulation results, the floor-supply displacement air-conditioning system with outdoor air cooling requires 34% less energy than the conventional air-conditioning system with outdoor air cooling.

Akimoto, Takashi; Nobe, Tatsuo; Tanabe, Shinichi; Kimura, Kenichi

1999-07-01

345

Integrated laboratory scale demonstration experiment of S-I cycle  

SciTech Connect

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

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

2007-07-01

346

Stable carbon and oxygen isotope fractionation processes during speleothem growth: systematic investigation in novel laboratory experiments  

NASA Astrophysics Data System (ADS)

The most widely applied climate proxies in speleothems are stable carbon and oxygen isotopes (?13C and ?18O). The interpretation of the stable isotope signals in terms of past temperature and/or precipitation variability is complex because both ?18O and ?13C depend on a complex interplay of various processes occurring in the atmosphere, the soil and karst above the cave and inside the cave. Quantitative reconstruction of climate parameters such as temperature and precipitation has, thus, remained impossible so far. Here we present several novel laboratory experiments aiming to understand the basic physical and chemical processes affecting the ?18O and ?13C signals during precipitation of calcium carbonate on the stalagmite surface. In particular, we aim to quantify the influence of kinetic isotope fractionation and verify recently published modelling studies (Dreybrodt, 2008; Scholz et al., 2009, Dreybrodt and Scholz, 2011). Several experiments are conducted: Degassing of CO2 from a thin film of water sparged with CO2 flowing down an inclined glass plate. pH and electric conductivity are systematically documented in order to monitor degassing of CO2. The results show that degassing of CO2 is fast, and the pCO2 of the solution is in equilibrium with the atmosphere after a short distance of flow. Carbon isotope exchange between atmospheric CO2 and dissolved bicarbonate. The results show that carbon isotope exchange may have a significant effect on the ?13C value of the dissolved bicarbonate and, thus, speleothem calcite, in particular for slow drip rates. Degassing of CO2 and calcite precipitation from a thin film of water supersaturated with respect to calcite flowing down an inclined calcium carbonate plate. Drip water is sampled after different lengths of flow path and, thus, different residence times on the plate, and pH, electrical conductivity and the stable isotope composition of the water are determined. Decreasing conductivity with increasing distance of flow path documents precipitation of calcium carbonate. We observe progressively increasing ?13C and ?18O values with increasing distance of flow in agreement with the model predictions. Calcite precipitation from a thin film of water supersaturated with respect to calcite flowing down an inclined glass plate. The precipitated calcite shows a clear enrichment in both ?13C and ?18O, and the absolute values are in good agreement with the stable isotope values of the dissolved bicarbonate (see experiment 3).

Scholz, D.; Hansen, M.; Dreybrodt, W.

2012-04-01

347

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

PubMed

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

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

2006-11-11

348

Oeresund-Experiment - Meteorological Measurements (Masts, Turbulence, Mini-Sondes) Performed by Risoe National Laboratory.  

National Technical Information Service (NTIS)

This report describes the measurements carried out by Risoe National Laboratory as part of the Oeresund experiment. Measurements were made of 1) turbulence at the Gladsaxe mast during tracer releases, 2) profiles of wind and temperature at four small mast...

N. Gylling Mortensen S. E. Gryning

1986-01-01

349

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

ERIC Educational Resources Information Center

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

Tsionsky, Vladimir

2007-01-01

350

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

ERIC Educational Resources Information Center

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

Sall, Eri; And Others

1978-01-01

351

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

NSDL National Science Digital Library

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

2011-06-01

352

Effect of the disposal of sludge from olive processing on some soil characteristics: Laboratory experiments  

Microsoft Academic Search

A laboratory experiment was performed during a 40-day incubation period in order to evaluate changes in organic and inorganic compounds of soil amended with two doses of sludge obtained from olive-oil processing waste waters.

Riccardo Riffaldi; Renato Levi-Minzi; Alessandro Saviozzi; Giacomo Vanni; Alessandra Scagnozzi

1993-01-01

353

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

354

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

Microsoft Academic Search

The AECL, Whiteshell Laboratory (WL) near Pinawa Manitoba, Canada, was established in the early 1960's to carry out AECL research and development activities for higher temperature versions of the CANDU{reg_sign} reactor. The initial focus of the research program was the Whiteshell Reactor-1 (WR-1) Organic Cooled Reactor (OCR) that began operation in 1965. The OCR program was discontinued in the early

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

2002-01-01

355

Low-Temperature, High-Field Susceptometry and Magnetometry Experiments for Undergraduate Laboratories  

Microsoft Academic Search

Cryogenic susceptometer\\/magnetometers are instruments commonly used in research labs to study magnetic materials; however they can also be used in the undergraduate laboratory to teach fundamental physical principles such as quantized angular momentum, statistical mechanics, and exchange interactions. We have developed three solid-state physics experiments for our modern physics and advanced laboratory courses using a cryogenic susceptometer\\/magnetometer. Our \\

Charles Cunningham; Matthew Cochran; Adam Rinehart

1998-01-01

356

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

ERIC Educational Resources Information Center

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

Leung, Sam H.; Angel, Stephen A.

2004-01-01

357

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

ERIC Educational Resources Information Center

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

Leung, Sam H.; Angel, Stephen A.

2004-01-01

358

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…

Feist, Patty L.

2008-01-01

359

Using Laboratory Experiments and Circuit Simulation IT Tools in an Undergraduate Course in Analog Electronics  

ERIC Educational Resources Information Center

Laboratory-based courses play a significant role in engineering education. Given the role of electronics in engineering and technology, laboratory experiments and circuit simulation IT tools are used in their teaching in several academic institutions. This paper discusses the characteristics and benefits of both methods. The content and structure…

Baltzis, Konstantinos B.; Koukias, Konstantinos D.

2009-01-01

360

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

Microsoft Academic Search

Physics is an experimental science. In other words, all physical laws are based on experimentally observable phenomena. Therefore, it is important that all physics students have an understanding of the limitations of certain experimental techniques and the associated errors associated with a particular measurement. The students in the Advanced Laboratory class at Texas State perform three detailed laboratory experiments during

Carl Ventrice

2009-01-01

361

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

362

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

363

Conducting Design Experiments to Support Teachers' Learning: A Reflection from the Field  

ERIC Educational Resources Information Center

|This article focuses on 3 conceptual challenges that we sought to address while conducting a design experiment in which we supported the learning of a group of middle school mathematics teachers. These challenges involved (a) situating teachers' activity in the institutional setting of the schools and district in which they worked, (b) developing…

Cobb, Paul; Zhao, Qing; Dean, Chrystal

2009-01-01

364

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

Microsoft Academic Search

Tracer experiments conducted using a flow field established by injecting water into one borehole and withdrawing water from another are often used to establish connections and investigate dispersion in fractured rock. As a result of uncertainty in the uniqueness of existing models used for interpretation, this method has not been widely used to investigate more general transport processes including matrix

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

2004-01-01

365

Accuracy in thermal contact conductance experiments - the effect of heat losses to the surroundings  

Microsoft Academic Search

A major source of uncertainty in contact heat transfer experiments is the heat loss from the specimens to the surroundings by convection, conduction and radiation. A detailed analysis is presented comparing the resistance to heat transfer across the joint to the resistance to heat flow from the specimens to the surroundings. It is shown that the heat losses may be

C. V. Madhusudana

2000-01-01

366

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

367

Conducting Design Experiments to Support Teachers' Learning: A Reflection From the Field  

Microsoft Academic Search

This article focuses on 3 conceptual challenges that we sought to address while conducting a design experiment in which we supported the learning of a group of middle school mathematics teachers. These challenges involved (a) situating teachers' activity in the institutional setting of the schools and district in which they worked, (b) developing an interpretive framework that enabled us to

Paul Cobb; Qing Zhao; Chrystal Dean

2009-01-01

368

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

369

Tailored blast wave formation: Developing experiments pertinent to laboratory astrophysics  

NASA Astrophysics Data System (ADS)

The first production of ``tailored'' blast waves in a cluster media using an intense, 2×1016 W cm-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 (<1015 W cm-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 ~6 ns in H2. 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.

2005-05-01

370

The LBL (Lawrence Berkeley Laboratory) multiple beam experiments  

SciTech Connect

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

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

1987-03-01

371

Phosphatidylcholine from "Healthful" Egg Yolk Varieties: An Organic Laboratory Experience  

NASA Astrophysics Data System (ADS)

I have added an investigative element to a popular undergraduate experiment. the characterization of phosphatidylcholine (PC) from egg yolks. Varieties of eggs are commercially available which have been obtained from chickens fed a diet containing no animal fat. Presumably, less saturated fat in the diet of the chickens could be reflected in the fatty acid composition of various classes of biological lipids, including phospholipids, in the eggs from these chickens. PC is extracted using conventional methods, the extract is further purified by chromatography on silicic acid, and the column fractions are assayed for the presence and purity of PC by TLC. Fractions containing pure PC are pooled, concentrated, hydrolyzed, and esterified to obtain the fatty acid methyl esters (FAME) which are identified by GLC. Comparing FAMEs derived from PC of yolks of regular eggs to those obtained from the other special brands adds a novel twist to the students' work and generates greater student interest and involvement in both the interpretation of data than a simple isolation of a biological compound alone evokes.

Hodges, Linda C.

1995-12-01

372

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

SciTech Connect

The National Renewable Energy Laboratory (NREL) contracted with conversion companies in six states to convert approximately 900 light-duty Federal fleet vehicles to operate on compressed natural gas (CNG) or liquefied petroleum gas (LPG). The contracts were initiated in order to help the Federal government meet the vehicle acquisition requirements of the Energy Policy Act of 1992 (EPACT) during a period of limited original equipment manufacturer (OEM) model availability. Approximately 90% of all conversions were performed on compact of full-size vans and pickups, and 90% of the conversions were to bi-fuel operation. With a positive response from the fleet managers, this program helped the Federal government meet the vehicle acquisition requirements of EPACT for fiscal years 1993 and 1994, despite limited OEM model availability. The conversions also helped to establish the infrastructure needed to support further growth in the use of alternative fuel vehicles. In conclusion, the program has been successful in helping the Federal government meet the vehicle acquisition requirements of EPACT, establishing infrastructure, increasing the displacement of imported oil, and evaluating the emissions performance of converted vehicles. With the relatively widespread availability of OEM vehicles in the 1996 model year, the program is now being phased out.

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

1996-04-01

373

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

374

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

375

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

376

Permeability measurements in undergraduate vacuum laboratories: a simple experiment using a He leak detector  

Microsoft Academic Search

We describe a simple experiment intended for didactic laboratory vacuum classes of undergraduate courses, using a helium leak detector. The helium throughput flowing into the vacuum volume due to the permeability of materials can be taken as a real leak, which can be measured with the helium leak detector. The experiment allows students to perform actual measurements of helium permeability

J M F dos Santos; J F C A Veloso; C M B Monteiro

2004-01-01

377

Determination of rest mass energy of the electron—an undergraduate laboratory experiment  

Microsoft Academic Search

We present a simple Compton scattering experiment to determine the rest mass energy of the electron which is unique for graduate and undergraduate laboratories. In the present experiment, we have measured the energies of the backscattered gamma photons with an NaI(Tl) gamma ray spectrometer coupled to a 1 K multichannel analyser. In order to enhance the backscattered gamma photons, a

S B Hosur; N M Badiger

2007-01-01

378

Residual gas analysers in an undergraduate vacuum laboratory: a simple experiment involving direct quantitative measurements  

Microsoft Academic Search

We describe a simple experiment intended for didactic laboratory vacuum classes of undergraduate courses, using a residual gas analyser (RGA): the determination of the natural abundance of the different isotopes of a given element in a gas sample. In addition to the understanding of the RGA operation and handling principles, the experiment allows the students to perform direct quantitative measurements

J M F dos Santos; A M F Trindade; J F C A Veloso; C M B Monteiro

2004-01-01

379

Determination of rest mass energy of the electron---an undergraduate laboratory experiment  

Microsoft Academic Search

We present a simple Compton scattering experiment to determine the rest mass energy of the electron which is unique for graduate and undergraduate laboratories. In the present experiment, we have measured the energies of the backscattered gamma photons with an NaI(Tl) gamma ray spectrometer coupled to a 1 K multichannel analyser. In order to enhance the backscattered gamma photons, a

S. B. Hosur; N. M. Badiger

2007-01-01

380

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

Microsoft Academic Search

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

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

2004-01-01

381

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

382

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

383

A critical review of Seligman's laboratory experiments on learned helplessness and depression in humans  

Microsoft Academic Search

Reviews 6 laboratory experiments reported by M. E. Seligman and his colleagues (W. R. Miller and Seligman, 1973; Miller and Seligman, 1975; Miller et al, 1975; Miller and Seligman, 1976; D. C. Klein and Seligman, 1976; Klein et al, 1976). The experiments are found to provide little or no support for the learned helplessness theory of depression. A number of

Charles G. Costello

1978-01-01

384

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

385

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

386

An ``Original'' Experiment in Heat for the First-Year Laboratory  

Microsoft Academic Search

There is need for elementary experiments in which the ``research spirit'' is present. Such an experiment involving the measurement of low temperatures has been used in both general physics and physical sciences laboratories. Each pair of students is required to devise its own method for measuring the temperature of a dry ice-alcohol mixture, to design and construct its apparatus, to

Ian G. Barbour; Ralph O. Kerman

1952-01-01

387

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

388

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

389

A reverse osmosis laboratory plant for experimenting with fault-tolerant control  

Microsoft Academic Search

A test bed for research and teaching in fault-tolerant control (FTC) systems is presented. The laboratory plant is based on an industrial reverse osmosis desalination plant equipped with standardized components, which introduces more realism and robustness into the experiments. This paper describes the plant, the mathematical model of the system and an illustrative experiment. Moreover, the problem of choosing the

A. Gambier; T. Miksch; E. Badreddin

2009-01-01

390

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

391

The Synthesis of 4,6,8-Trimethylazulene: An Organic Laboratory Experiment.  

ERIC Educational Resources Information Center

A two-stage synthesis of 4,6,8-trimethylazulene was developed for use in the undergraduate experiment, highlighting concepts not usually covered in the laboratory. The experiment requires purification procedures of chromatography and of sublimation and illustrates concepts of aromaticity, molecular orbital theory, and carbodium ion reactivity. (JN)

Garst, Michael E.; And Others

1983-01-01

392

Experiences with spectrum adaptation term and extended frequency range from field and laboratory measurements  

Microsoft Academic Search

At the Norwegian Building Research Institute (NBI), sound insulation measurements have been carried out in the frequency range from 50 to 5000 Hz since 1997. A major part of our experiences are from field measurements, but for some years we have also studied floor constructions in two different experiment set up at the laboratory. Since 2002, also ordinary sound transmission

Anders Homb

393

Quantitative imaging of contaminant distributions in heterogeneous porous media laboratory experiments  

Microsoft Academic Search

Intermediate-scale laboratory experiments on heterogeneous porous media have been increasingly used for the study of saturated and unsaturated ground water systems. While the ability to reproduce field-scale heterogeneity in these experiments has advanced, the use of visualization or image analysis methods to characterize the spatial distribution of solute concentrations has largely remained at the homogeneous media level. To advance these

J. D. McNeil; G. A. Oldenborger; R. A. Schincariol

2006-01-01

394

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

ERIC Educational Resources Information Center

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

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

2005-01-01

395

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

ERIC Educational Resources Information Center

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

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

2011-01-01

396

Development of a Jet Engine Experiment for the Energy Systems Laboratory  

Microsoft Academic Search

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

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

397

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

398

On-line identification design for a flexible beam laboratory adaptive control experiment  

Microsoft Academic Search

Experience with system identification design for a flexible beam laboratory experiment adaptive controller is discussed. Among the limitations faced were the presence of unmodelled high frequency modes and the use of an accelero-meter as the primary motion sensor. These limitations motivated the development of a novel robust identification approach which is applicable to a large class of flexible structures.

G. A. McGRAW

1995-01-01

399

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

ERIC Educational Resources Information Center

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

Duxbury, Mark

2004-01-01

400

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

ERIC Educational Resources Information Center

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

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

2008-01-01

401

Prospective Teachers' Perceptions of the Value of an Early Field Experience in a Laboratory Setting  

ERIC Educational Resources Information Center

|Because there is limited research on effective early field experiences and, particularly, on the potential of laboratory experiences to expose teacher candidates to a diverse student population, this study evaluates one such placement. As part of the placement, the teacher candidate provided tutoring at an on-campus model alternative program for…

Wasburn-Moses, Leah; Kopp, Tom; Hettersimer, Jill E.

2012-01-01

402

Cleaning oiled shores: laboratory experiments testing the potential use of vegetable oil biodiesels  

Microsoft Academic Search

A series of laboratory experiments were carried out to test the potential of vegetable oil biodiesel for the cleaning of oiled shorelines. In batch experiments, biodiesel was shown to have a considerable capacity to dissolve crude oil, which appears to be dependent on the type of biodiesel used. Pure vegetable oil biodiesels (rapeseed and soybean) were significantly more effective in

M. Glória Pereira; Stephen M. Mudge

2004-01-01

403

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

404

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

Microsoft Academic Search

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

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

1996-01-01

405

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

ERIC Educational Resources Information Center

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

Collins, Lee A.; And Others

1974-01-01

406

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

407

Constraints on Structure and Melting of Heterogeneous Plumes From Laboratory Experiments With Three Components  

NASA Astrophysics Data System (ADS)

Many studies of chemical geodynamics consider the fate of a single, compositionally distinct layer at the base of the mantle, but subducted oceanic lithosphere introduces two distinct lithologies (higher-density eclogite and lower-density harzburgite) into the mantle (a third lithology, intermediate-density lherzolitic peridotite). To address the dynamic complexities of interactions between these materials, we conducted three-dimensional laboratory experiments that use glucose syrup (Rayleigh number: 106\\)) to model the mantle and a two-layer subducted lithosphere. The viscosity and density of the syrup are controlled by its water content, which is varied to simulate the distinct physical properties of each of the three lithologies. Experiments were conducted in a 20cc tank, heated from below to create a basal thermal boundary layer (BTBL). The two-layer glucose slab was frozen and placed within the tank, where it sank into the BTBL. These experiments produced heterogeneous upwellings with temporal and spatial variations in both temperature and composition that are much more complex than predicted by classic plume theory. Temperature, composition, and distribution of material in the tank through space and time were recorded during each experiment. We scale these data to mantle-equivalent conditions and address the observational implication for melting such heterogeneous plumes, both within larger (200 - 600 km) plume heads and smaller (<100 km) trailing conduits. Results show length scales of chemical heterogeneity range from <10 km up to 300 km. Thermal heterogeneity was often correlated with composition, where the denser, eclogite analog had higher temperatures than the lighter, harzburgite analog. Distinct domains form within plumes and melting begins at different depths, dependent on the temperature and composition of each domain and the solidus of each composition (e.g. eclogite melts at lower temperatures than harzburgite). The combination of thermo-chemical variation and differences in solidi explains heterogeneous melting behavior. In many cases, whole portions of buoyant plume heads either never reach the dry solidus, or predict very small melt fractions, and primarily serve as pathways for the ascent of subsequent fusible material.

Harris, A. C.; Kincaid, C.; Kelley, K. A.

2007-12-01

408

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

409

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

NASA Astrophysics Data System (ADS)

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

Straface, Salvatore; Rizzo, Enzo; Chidichimo, Francesco

2010-06-01

410

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

NASA Astrophysics Data System (ADS)

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

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

2010-04-01

411

Database dictionary for the results of groundwater tracer tests using tritiated water, conducted at the Oak Ridge National Laboratory  

SciTech Connect

In 1977, the United States Geological Survey (USGS) conducted two tracer tests at the Oak Ridge National Laboratory (ORNL) using tritiated water to study the relative importance of bedding-plane openings on shallow groundwater flow. Through a cooperative agreement between the USGS and the US Department of Energy (DOE), the data were made available to researchers at the Oak Ridge National Laboratory (ORNL), who organized the data into a data management format. The results of these groundwater tracer tests have been compiled into a collection of four SAS data sets. This report documents these SAS data sets, including their structure, methodology, and content. The SAS data sets include information on precipitation, tritium, water levels, and well construction for wells at or near ORNL radioactive waste burial grounds 4, 5, and 6.

Thompson, B.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Civil Engineering; Huff, D.D. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

1997-05-01

412

Simultaneous Determination of the Hydraulic Conductivity and Specific Storage of A Test Specimen From Laboratory Permeability Tests  

NASA Astrophysics Data System (ADS)

Laboratory testing of representative specimens has been a very useful and widely adopted approach for characterizing the physical properties of geological materials. One of the particular challenges in geotechnical and/or geoenvironmental laboratory testing is the accurate determination of the hydraulic properties of low-permeability geological materials such as clays, intact rocks and the mixtures of sand and clay. These materials are now being studied in increasing detail because of their importance in retarding the transport of hazardous wastes, including radioactive nuclear wastes. Although laboratory permeability tests are thought to be well-established, most methods can obtain only the value of hydraulic conductivity and the specific storage, another important parameter related to the transient flow, is disregarded in the analyses. In addition, conventional test methods require relatively-long times for testing low-permeability geological materials. In this study, we present a set of rigorous solutions to three kinds of laboratory permeability tests: the constant-head, rising tail-water elevation; the falling-head, constant tail-water elevation; and the falling-head, rising tail-water elevation. A new system that can implement any of these three test methods is also introduced. This new system permits automated recording of the heads in up and down streams, eliminating the effects of temperature variation and evaporation on flow rate measurements. The applicabilities and advantages of these improved technologies are demonstrated using a series of experimental data derived from a compacted mixture of sand and clay. The results indicated that using the rigorous solutions to analyze unsteady or transient-phase data obtained from individual permeability tests permits the test durations to be shorted without sacrificing accuracy in estimating both the hydraulic conductivity and the specific storage of a test specimen.

Zhang, M.; Takeda, M.; Aung, T. T.

2004-12-01

413

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

Microsoft Academic Search

Cross-sectional conductivity images of lower extremities were reconstructed using Magnetic Resonance Electrical Impedance Tomography (MREIT) techniques. Carbon-hydrogel electrodes were adopted for postmortem swine and in vivo human imaging experiments. Due to their large surface areas and good contacts on the skin, we could inject as much as 10 mA into the lower extremities of human subjects without producing a painful

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

2008-01-01

414

Einstein-Podolsky-Rosen-Bohm laboratory experiments: Data analysis and simulation  

NASA Astrophysics Data System (ADS)

Data produced by laboratory Einstein-Podolsky-Rosen-Bohm (EPRB) experiments is tested against the hypothesis that the statistics of this data is given by quantum theory of this thought experiment. Statistical evidence is presented that the experimental data, while violating Bell inequalities, does not support this hypothesis. It is shown that an event-based simulation model, providing a cause-and-effect description of real EPRB experiments at a level of detail which is not covered by quantum theory, reproduces the results of quantum theory of this thought experiment, indicating that there is no fundamental obstacle for a real EPRB experiment to produce data that can be described by quantum theory.

Raedt, H. De; Michielsen, K.; Jin, F.

2012-03-01

415

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

416

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

SciTech Connect

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

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

1995-09-01

417

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

PubMed Central

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

Samaila, Modupeola Omotara; Abdullahi, Kabiru

2011-01-01

418

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

419

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

PubMed Central

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

TARAS, LORETTA BRANCACCIO

2003-01-01

420

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

421

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

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

422

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

NASA Astrophysics Data System (ADS)

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

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

2009-12-01

423

Designing experiments on thermal interactions by secondary-school students in a simulated laboratory environment  

Microsoft Academic Search

The aim of this study was to explore the effect of investigative activities with manipulations in a virtual laboratory on students’ ability to design experiments.SampleFourteen students in a lower secondary school in Greece attended a teaching sequence on thermal phenomena based on the use of information and communication technology, and specifically of the simulated virtual laboratory ‘ThermoLab’.Design and methodsA pre–post

Ioannis Lefkos; Dimitris Psillos; Euripides Hatzikraniotis

2011-01-01

424

Transformations in organic sulfur speciation during maturation of Monterey shale: Constraints from laboratory experiments.  

National Technical Information Service (NTIS)

A series of hydrous pyrolysis experiments were conducted at temperatures ranging from 125 to 360C at 350 bars pressure to examine variations in sulfur speciation during thermal maturation of Monterey shale. The total sediment, kerogen and bitumen from eac...

B. C. Nelson T. I. Eglinton J. S. Seewald M. A. Vairavamurthy F. P. Miknis

1995-01-01

425

Dose reconstruction for weapons experiments involving 140La at Los Alamos National Laboratory, 1944-1962.  

PubMed

A series of 254 weapons design experiments was conducted by Los Alamos National Laboratory from 1944 through 1962 and resulted in the dispersal of approximately 11 PBq (300 kCi) of radioactive 140La. All shots occurred at Point Able in Bayo Canyon, east of the Los Alamos townsite. Public interest and the Government Accounting Office probe precipitated a dose reconstruction to assess potential exposures to members of the public. The information available for each shot included explosive charge size, date and time of explosion, and shot activity. Detailed meteorological data were not available for the majority of the shots, requiring the development of statistically representative meteorological data. A wind rose was developed specific to the afternoon-evening time of the shots, and the wind frequency in each sector was used to determine the fraction of activity dispersed towards each hypothetical receptor. HOTSPOT 7, a Gaussian plume-based dispersion model, was used to determine the average dose per sector per unit of shot activity. The dose from penetrating radiation from ground-deposited 140La was greater by several orders of magnitude than the dose from inhalation and immersion. The highest doses to a permanent resident probably occurred in the easternmost part of the Los Alamos townsite. The highest annual dose occurred in 1955 and was approximately 0.23 mSv. Assuming an individual had been at the location of maximum potential exposure in the Los Alamos townsite continuously throughout the experiments, the total dose from the 18-y series would have been approximately 1.4 mSv with an average dose of approximately 0.09 mSv y(-1). Doses at nearby Totavi trailer park, San Ildefonso Pueblo, and Santa Clara Pueblo were approximately 75%, 40%, and 15%, respectively, of those at Los Alamos. Visitors to nearby public areas received negligible doses. PMID:9314221

Kraig, D H

1997-10-01

426

CT-imaging assisted dual-permeability evaluation of a laboratory column experiment  

NASA Astrophysics Data System (ADS)

To predict quantitatively the water movement in variably saturated natural porous media exhibiting preferential flow effects, the hydraulic properties of the media have to be adequately described. A laboratory infiltration-outflow experiment performed on an undisturbed soil column was developed to study the dynamics of flow in heterogeneous soil and to measure the hydraulic conductivity function. The experimental setup with automated data acquisition was used (Snehota et al., 2002). The unsaturated flow through the sample was established by means of a disk tension infiltrometer. The data sets obtained in this experiment were used as an input for the estimation of the soil hydraulic properties by means of inverse modeling. It was assumed that the pore space is represented by a dual-permeability system, consisting of the matrix and the preferential flow domain (PFD), in which the PFD occupies a certain fraction of the bulk soil. The S_1D_DUAL code, as a one-dimensional dual-permeability simulator was coupled with the parameter estimator PEST (Waterloo Hydrogeologic), based on the Levenberg-Marquardt algorithm. The hydraulic parameters were optimized in the least-square sense. Both the cumulative infiltration data and the pressure head data were included in the objective function. As an alternative to the constant volume fraction of the PFD, the fraction values changing along the depth of the column were used for optimization. The space variable values of the PFD fraction were obtained from the 3D CT image analysis. The latter approach was found to yield significant improvement in terms of the fit between simulated and measured values. The research was supported by the Grant Agency of the Academy of Sciences of the Czech Republic, grant A3060001.

Dohnal, M.; Snehota, M.; Cislerova, M.; Vogel, T.

2003-04-01

427

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

Microsoft Academic Search

For several years tracer migration experiments are performed at Nagra's Grimsel Test Site in the Swiss Alps as a joint undertaking of Nagra, PNC and PSI. The aim is to develop methods for field experiments at possible sites for nuclear waste repositories and to test radionuclide transport models.A hydraulic dipole field is generated in a well-defined fracture zone in granite.

Jörg Hadermann; Walter Heer

1996-01-01

428

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

SciTech Connect

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

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

2003-03-01

429

Ghost imaging experiment with sunlight compared to laboratory experiment with thermal light  

NASA Astrophysics Data System (ADS)

A recent article reports on the demonstration of ghost imaging using sunlight which also presents theory for ghost imaging in the atmosphere based on two photon interference. The current paper reviews the experiment from a different context than that presented by Karmakar, Meyers and Shih (KMS). Here we examine data from the KMS sunlight ghost imaging experiment and compare it to ghost imaging produced by true thermal light.

Karmakar, Sanjit; Meyers, Ronald; Shih, Yanhua

2012-10-01

430

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

431

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

PubMed

It is increasingly easy and, therefore, increasingly common to conduct experiments and questionnaire studies in online environments. However, the online environment is not a data collection medium that is familiar to many researchers or to many research methods instructors. Because of this, researchers have received little information about how to address ethical issues when conducting online research. Researchers need practical suggestions on how to translate federal and professional ethics codes into this new data collection medium. This article assists United States psychologists in designing online studies that meet accepted standards for informed consent, deception, debriefing, the right to withdraw, security of test materials, copyright of participants' materials, confidentiality and anonymity, and avoiding harm. PMID:19001403

Barchard, Kimberly A; Williams, John

2008-11-01

432

High-temperature Y267 epdm elastomer - field and laboratory experiences, August 1981  

SciTech Connect

During the period 1976 to 1979 L'Garde, Inc. developed geothermal elastomer compounds under a U.S. Department of Energy - Division of Geothermal Energy (DOE-DGE) contract. The resulting developments yielded compounds from 4 polymer systems which successfully exceeded the contract requirements. Since completion of the compound development, significant laboratory and down-hole experience occurred, primarily on the Y267 EPDM compound. This work summarizes those experiences. 11 references.

Hirasuna, A.R.; Friese, G.J.; Stephens, G.A.

1982-01-01

433

The use of laboratory experiments for the study of conservative solute transport in heterogeneous porous media  

Microsoft Academic Search

Laboratory experiments on heterogeneous porous media (otherwise known as intermediate scale experiments, or ISEs) have been\\u000a increasingly relied upon by hydrogeologists for the study of saturated and unsaturated groundwater systems. Among the many\\u000a ongoing applications of ISEs is the study of fluid flow and the transport of conservative solutes in correlated permeability\\u000a fields. Recent advances in ISE design have provided

S. E. Silliman; L. Zheng; P. Conwell

1998-01-01

434

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

NASA Astrophysics Data System (ADS)

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

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

1995-11-01

435

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

436

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

437

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

NASA Astrophysics Data System (ADS)

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

Ventrice, Carl

2009-04-01

438

A 201-MHz Normal Conducting RF Cavity for the International MICE Experiment  

SciTech Connect

MICE is a demonstration experiment for the ionization cooling of muon beams. Eight RF cavities are proposed to be used in the MICE cooling channel. These cavities will be operated in a strong magnetic field; therefore, they must be normal conducting. The cavity design and construction are based on the successful experience and techniques developed for a 201-MHz prototype cavity for the US MUCOOL program. Taking advantage of a muon beamâ s penetration property, the cavity employs a pair of curved thin beryllium windows to terminate conventional beam irises and achieve higher cavity shunt impedance. The cavity resembles a round, closed pillbox cavity. Two half-shells spun from copper sheets are joined by e-beam welding to form the cavity body. There are four ports on the cavity equator for RF couplers, vacuum pumping and field probes. The ports are formed by means of an extruding technique.

Li, D.; DeMello, A.J.; Virostek, Steve; S. Zisman, Michael; Rimmer, Robert

2008-07-01

439

Testing the Relationship Between Levels of Endogenous Testosterone and Physiological Responses to Facial Expressions in Men: An Experiment Conducted by Students in an Undergraduate Behavioral Neuroscience Class  

PubMed Central

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

Thompson, Richmond R.; George, Kirsten

2003-01-01

440

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

441

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

442

Department of Energy's solar technology transfer program: the Lawrence Livermore Laboratory experience  

Microsoft Academic Search

The Lawrence Livermore Laboratory (LLL) under the direction of the Department of Energy's (DOE's) Solar Technology Transfer Program (STTP) has designed and implemented a regionalized solar commercialization outreach program. Primary target audiences in Arizona, California, Hawaii and Nevada include architects, builders, lenders, contractors, plumbers, manufacturers, distributors as well as educational institutions, state and local offices, and library systems. The experience

1979-01-01

443

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

Microsoft Academic Search

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

SHINGO TAKADA; LOUISE SCOTT; ANDY BROOKS

444

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

445

Design Experiments and Laboratory Approaches to Learning: Steps toward Collaborative Exchange.  

ERIC Educational Resources Information Center

|Explores how the emerging goals, approaches, and methodologies of design experiments might be productively combined with methods of inquiry common in more traditional laboratory science, considering the potential benefits of such a dialectic. Presents three examples of collaboration and describes steps toward productive exchange (identifying…

McCandliss, Bruce D.; Kalchman, Mindy; Bryant, Peter

2003-01-01

446

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

ERIC Educational Resources Information Center

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

Lefkos, Ioannis; Psillos, Dimitris; Hatzikraniotis, Euripides

2011-01-01

447

Crater formation in the laboratory: An introductory experiment in error analysis  

Microsoft Academic Search

One of the primary objectives of the introductory physics laboratory is to teach error analysis. We describe a very simple and inexpensive experiment which exposes students to the central ideas of estimation and uncertainty, and to the evaluation of theory by graphical display of data. The task is to measure the diameter of a crater formed by dropping a small

Joseph C. Amato; Roger E. Williams

1998-01-01

448

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

449

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

ERIC Educational Resources Information Center

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

Schepmann, Hala G.; Mynderse, Michelle

2010-01-01

450

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

ERIC Educational Resources Information Center

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

Lefkos, Ioannis; Psillos, Dimitris; Hatzikraniotis, Euripides

2011-01-01

451

A novel approach to controlling dissolved oxygen levels in laboratory experiments  

Microsoft Academic Search

Hypoxia is a widespread environmental stressor that affects marine, estuarine and freshwater systems worldwide. Investigating the effects of hypoxia on aquatic animals in the natural environment is difficult and expensive. Laboratory experiments provide an alternative that allows manipulation of environmental variables and simulation of altered conditions that are expected in the future. However, controlling dissolved oxygen (DO) levels precisely in

K. L. Hassell; P. C. Coutin; D. Nugegoda

2009-01-01

452

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

453

Bacterial Production of Poly(3-hydroxybutyrate): An Undergraduate Student Laboratory Experiment  

ERIC Educational Resources Information Center

|As part of a multidisciplinary course that is cross-listed between five departments, we developed an undergraduate student laboratory experiment for culturing, isolating, and purifying the biopolymer, poly(3-hydroxybutyrate), PHB. This biopolyester accumulates in the cytoplasm of bacterial cells under specific growth conditions, and it has…

Burns, Kristi L.; Oldham, Charlie D.; May, Sheldon W.

2009-01-01

454

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

455

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

456

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

457

The Quartz-Crystal Microbalance in an Undergraduate Laboratory Experiment: Measuring Mass  

ERIC Educational Resources Information Center

|The study explains the quartz-crystal microbalance (QCM) technique, which is often used as an undergraduate laboratory experiment for measuring the mass of a system. QCM can be used as a mass sensor only when the measured mass is rigidly attached to the surface.|

Tsionsky, Vladimir

2007-01-01

458

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

459

Human factors in telemanipulation: perspectives from the Oak Ridge National Laboratory experience  

Microsoft Academic Search

Personnel at the Robotics and Process Systems Division (RPSD) of the Oak Ridge National Laboratory have extensive experience designing, building, and operating teleoperators for a variety of settings, including space, battlefields, nuclear fuel reprocessing plants, and hazardous waste retrieval. In the course of the last decade and a half, the RPSD designed, built, and operated 4 telemanipulators (M-2, ASM, LTM,

John V. Draper

1993-01-01

460

Human factors in telemanipulation: Perspectives from the Oak Ridge National Laboratory experience  

Microsoft Academic Search

Personnel at the Robotics and Process Systems Division (RPSD) of the Oak Ridge National Laboratory (ORNL) have extensive experience designing, building, and operating teleoperators for a variety of settings, including space, battlefields, nuclear fuel reprocessing plants, and hazardous waste retrieval. In the course of the last decade and a half, the RPSD designed, built, and operated 4 telemanipulators (M-2, ASM,

Draper

1994-01-01