Science.gov

Sample records for laboratory collision experiments

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

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

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

  2. Verification of Compton Collision and Klein-Nishina Formulas--An Undergraduate Laboratory Experiment

    ERIC Educational Resources Information Center

    Singhal, R. P.; Burns, A. J.

    1978-01-01

    Describes an experiment to verify the Compton collision formula and the angular dependance of the Klein-Nishina formula. Equipment used is a 1-mCi(137)Cs source, 2x2 in. NaI detector and a multichannel analyzer. Suitable for honor undergraduates. (Author/GA)

  3. Verification of Compton Collision and Klein-Nishina Formulas--An Undergraduate Laboratory Experiment

    ERIC Educational Resources Information Center

    Singhal, R. P.; Burns, A. J.

    1978-01-01

    Describes an experiment to verify the Compton collision formula and the angular dependance of the Klein-Nishina formula. Equipment used is a 1-mCi(137)Cs source, 2x2 in. NaI detector and a multichannel analyzer. Suitable for honor undergraduates. (Author/GA)

  4. Ball Collision Experiments

    ERIC Educational Resources Information Center

    Cross, R.

    2015-01-01

    Experiments are described on collisions between two billiard balls and between a bat and a ball. The experiments are designed to extend a student's understanding of collision events and could be used either as a classroom demonstration or for a student project.

  5. Ball Collision Experiments

    ERIC Educational Resources Information Center

    Cross, R.

    2015-01-01

    Experiments are described on collisions between two billiard balls and between a bat and a ball. The experiments are designed to extend a student's understanding of collision events and could be used either as a classroom demonstration or for a student project.

  6. Degree of impactor fragmentation under collision with a regolith surface—Laboratory impact experiments of rock projectiles

    NASA Astrophysics Data System (ADS)

    Nagaoka, Hiroki; Takasawa, Susumu; Nakamura, Akiko M.; Sangen, Kazuyoshi

    2014-01-01

    Some meteorites consist of a mix of components of various parent bodies that were presumably brought together by past collisions. Impact experiments have been performed to investigate the degree of target fragmentation during such collisions. However, much less attention has been paid to the fate of the impactors. Here, we report the results of our study of the empirical relationship between the degree of projectile fragmentation and the impact conditions. Millimeter-sized pyrophyllite and basalt projectiles were impacted onto regolith-like sand targets and an aluminum target at velocities of up to 960 m s-1. Experiments using millimeter-sized pyrophyllite blocks as targets were also conducted to fill the gap between this study and the previous studies of centimeter-sized rock targets. The catastrophic disruption threshold for a projectile is defined as the energy density at which the mass of the largest fragment is the half of the original mass. The thresholds with the sand target were 4.5 ± 1.1 × 104 and 9.0 ± 1.9 × 104 J kg-1, for pyrophyllite and basalt projectiles, respectively. These values are two orders of magnitude larger than the threshold for impacts between pyrophyllite projectiles onto aluminum targets, but are qualitatively consistent with the fact that the compressive and tensile strengths of basalt are larger than those of pyrophyllite. The threshold for pyrophyllite projectiles and the aluminum target agrees with the threshold for aluminum projectiles and pyrophyllite targets within the margin of error. Consistent with a previous result, the threshold depended on the size of the rocks with a power of approximately -0.4 (Housen and Holsapple 1999). Destruction of rock projectiles occurred when the peak pressure was about ten times the tensile strength of the rocks.

  7. COLLIDE: Collisions into Dust Experiment

    NASA Technical Reports Server (NTRS)

    Colwell, Joshua E.

    1999-01-01

    The Collisions Into Dust Experiment (COLLIDE) was completed and flew on STS-90 in April and May of 1998. After the experiment was returned to Earth, the data and experiment were analyzed. Some anomalies occurred during the flight which prevented a complete set of data from being obtained. However, the experiment did meet its criteria for scientific success and returned surprising results on the outcomes of very low energy collisions into powder. The attached publication, "Low Velocity Microgravity Impact Experiments into Simulated Regolith," describes in detail the scientific background, engineering, and scientific results of COLLIDE. Our scientific conclusions, along with a summary of the anomalies which occurred during flight, are contained in that publication. We offer it as our final report on this grant.

  8. RELATIVISTIC HEAVY ION COLLISIONS: EXPERIMENT

    SciTech Connect

    Friedlander, Erwin M.; Heckman, Harry H.

    1982-04-01

    Relativistic heavy ion physics began as a 'no man's land' between particle and nuclear physics, with both sides frowning upon it as 'unclean', because on one hand, hadronic interactions and particle production cloud nuclear structure effects, while on the other, the baryonic environment complicates the interpretation of production experiments. They have attempted to review here the experimental evidence on RHI collisions from the point of view that it represents a new endeavor in the understanding of strong interaction physics. Such an approach appears increasingly justified; first, by the accumulation of data and observations of new features of hadronic interactions that could not have been detected outside a baryonic environment; second, by the maturation of the field owing to the advances made over the past several years in experimental inquiries on particle production by RHI, including pions, kaons, hyperons, and searches for antiprotons; and third, by the steady and progressive increase in the energy and mass ranges of light nuclear beams that have become available to the experiment; indeed the energy range has widened from the {approx} 0.2 to 2 AGeV at the Bevalac to {approx}4 AGeV at Dubna and recently, to the quantum jump in energies to {approx} 1000 equivalent AGeV at the CERN PS-ISR. Accompanying these expansions in the energy frontier are the immediate prospects for very heavy ion beams at the Bevalac up to, and including, 1 AGeV {sup 238}U, thereby extending the 'mass frontier' to its ultimate extent.

  9. Two LANL laboratory astrophysics experiments

    SciTech Connect

    Intrator, Thomas P.

    2014-01-24

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

  10. An Organoleptic Laboratory Experiment

    NASA Astrophysics Data System (ADS)

    Risley, John M.

    1996-12-01

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

  11. Estimating collision efficiencies from contact freezing experiments

    NASA Astrophysics Data System (ADS)

    Nagare, B.; Marcolli, C.; Stetzer, O.; Lohmann, U.

    2015-04-01

    Interactions of atmospheric aerosols with clouds influence cloud properties and modify the aerosol life cycle. Aerosol particles act as cloud condensation nuclei and ice nucleating particles or become incorporated into cloud droplets by scavenging. For an accurate description of aerosol scavenging and ice nucleation in contact mode, collision efficiency between droplets and aerosol particles needs to be known. This study derives the collision rate from experimental contact freezing data obtained with the ETH Collision Ice Nucleation Chamber CLINCH. Freely falling 80 μm water droplets are exposed to an aerosol consisting of 200 nm diameter silver iodide particles of concentrations from 500-5000 cm-3, which act as ice nucleating particles in contact mode. The chamber is kept at ice saturation in the temperature range from 236-261 K leading to slow evaporation of water droplets giving rise to thermophoresis and diffusiophoresis. Droplets and particles bear charges inducing electrophoresis. The experimentally derived collision efficiency of 0.13 is around one order of magnitude higher than theoretical formulations which include Brownian diffusion, impaction, interception, thermophoretic, diffusiophoretic and electric forces. This discrepancy is most probably due to uncertainties and inaccuracies in the description of thermophoretic and diffusiophoretic processes acting together. This is to the authors knowledge the first dataset of collision efficiencies acquired below 273 K. More such experiments with different droplet and particle diameters are needed to improve our understanding of collision processes acting together.

  12. Organic Laboratory Experiments.

    ERIC Educational Resources Information Center

    Smith, Sherrel

    1990-01-01

    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)

  13. Organic Laboratory Experiments.

    ERIC Educational Resources Information Center

    Smith, Sherrel

    1990-01-01

    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)

  14. Submillimeter Laboratory Investigations: Spectroscopy and Collisions

    NASA Technical Reports Server (NTRS)

    Herbst, Eric; DeLucia, Frank C.

    2002-01-01

    Currently, millimeter-wave and submillimeter-wave spectroscopy is conducted in our laboratory on several different types of spectrometers. Our standard spectrometer utilizes the output of a phase-locked klystron operating in the 40-60 GHz region, which is sent into a crossed-waveguide harmonic generator, or "multiplier". The high frequency millimeter-and submillimeter-wave radiation is transmitted via quasi-optical techniques through an absorption cell and then onto a detector, which is either an InSb hot electron bolometer cooled to 1.4 K or a Si bolometer cooled to 0.3 K. The detector response is sent to a computer for measurement and analysis. The frequency range produced and detected in this manner goes from 80 GHz to upwards of 1 THz. Spectra are normally taken with source modulation, with line frequencies typically measured to an accuracy of 50-100 kHz. Higher accuracy is available when needed. Recently, we developed a new, broad-band spectrometer in our laboratory based on a free-running backward wave oscillator (BWO) of Russian manufacture as the primary source of radiation. The so-called FASSST (fast-scan submillimeter spectroscopic technique) system uses fast-scan and optical calibration methods rather than the traditional locking techniques. The output power from the BWO is split such that 90% goes into the absorption cell while 10% is coupled to a 40-meter Fabry-Perot cavity, which yields fringe? for frequency measurement. Results from this spectrometer on the spectrum of nitric acid (HNO3) show that 100 GHz of spectral data can be obtained in 5 seconds with a measurement accuracy of 50 kHz. Currently, the frequency range of the FASSST system in our laboratory is roughly 100-700 GHz.

  15. Submillimeter Laboratory Investigations: Spectroscopy and Collisions

    NASA Astrophysics Data System (ADS)

    Herbst, Eric; DeLucia, Frank C.

    2002-10-01

    Currently, millimeter-wave and submillimeter-wave spectroscopy is conducted in our laboratory on several different types of spectrometers. Our standard spectrometer utilizes the output of a phase-locked klystron operating in the 40-60 GHz region, which is sent into a crossed-waveguide harmonic generator, or "multiplier". The high frequency millimeter-and submillimeter-wave radiation is transmitted via quasi-optical techniques through an absorption cell and then onto a detector, which is either an InSb hot electron bolometer cooled to 1.4 K or a Si bolometer cooled to 0.3 K. The detector response is sent to a computer for measurement and analysis. The frequency range produced and detected in this manner goes from 80 GHz to upwards of 1 THz. Spectra are normally taken with source modulation, with line frequencies typically measured to an accuracy of 50-100 kHz. Higher accuracy is available when needed. Recently, we developed a new, broad-band spectrometer in our laboratory based on a free-running backward wave oscillator (BWO) of Russian manufacture as the primary source of radiation. The so-called FASSST (fast-scan submillimeter spectroscopic technique) system uses fast-scan and optical calibration methods rather than the traditional locking techniques. The output power from the BWO is split such that 90% goes into the absorption cell while 10% is coupled to a 40-meter Fabry-Perot cavity, which yields fringe? for frequency measurement. Results from this spectrometer on the spectrum of nitric acid (HNO3) show that 100 GHz of spectral data can be obtained in 5 seconds with a measurement accuracy of 50 kHz. Currently, the frequency range of the FASSST system in our laboratory is roughly 100-700 GHz.

  16. Embedding Laboratory Experience in Lectures

    ERIC Educational Resources Information Center

    Morgan, James R.; Barroso, Luciana R.; Simpson, Nancy

    2009-01-01

    Demonstrations can be very effective at enhancing student learning and represent a mechanism for embedding laboratory experiences within a classroom setting. A key component to an effective demonstration is active student engagement throughout the entire process, leading to a guided laboratory experience in a lecture setting. Students are involved…

  17. Kinetic simulation of a plasma collision experiment

    NASA Astrophysics Data System (ADS)

    Larroche, Olivier

    1993-08-01

    The ionic Fokker-Planck code which was written for describing plasma shock wave fronts [M. Casanova et al. Phys. Rev. Lett. 67, 2143 (1991)] is applied to model the collision of two plasmas in plane geometry. Improvements brought to the code for that purpose are described. The initial phase of the experiment during which the plasmas interpenetrate is accounted for by a simple fluid model, which yields qualitative insight into the phenomena at play as well as an initial condition to start the kinetic simulation. The kinetic results obtained in the stagnation and thermalization phases are discussed with respect to a specific laser-produced plasma collision experiment, as well as to existing fluid and kinetic (``particle-in-cell'') simulations.

  18. COLLIDE-2: Collisions Into Dust Experiment-2

    NASA Technical Reports Server (NTRS)

    Colwell, Joshua E.

    2002-01-01

    The Collisions Into Dust Experimental (COLLIDE-2) was the second flight of the COLLIDE payload. The payload performs six low-velocity impact experiments to study the collisions that are prevalent in planetary ring systems and in the early stages of planet formation. Each impact experiment is into a target of granular material, and the impacts occur at speeds between 1 and 100 cm/s in microgravity and in a vacuum. The experiments are recorded on digital videotape which is later analyzed. During the period of performance a plan was developed to address some of the technical issues that prevented the first flight of COLLIDE from being a complete success, and also to maximize the scientific return based on the science results from the first flight. The experiment was modified following a series of reviews of the design plan, and underwent extensive testing. The data from the experiment show that the primary goal of identifying transition regimes for low-velocity impacts based on cratering versus accretion was achieved. Following a brief period of storage, the experiment flew regimes for low-velocity impacts based on cratering versus accretion was achieved. as a Hitchhiker payload on the MACH-1 Hitchhiker bridge on STS-108 in December 2001. These data have been analyzed and submitted for publication. That manuscript is attached to this report. The experiment was retrieved in January 2002, and all six impact experiments functioned nominally. Preliminary results were reported at the Lunar and Planetary Science Conference.

  19. Impact Crater Experiments for Introductory Physics and Astronomy Laboratories

    ERIC Educational Resources Information Center

    Claycomb, J. R.

    2009-01-01

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

  20. Impact Crater Experiments for Introductory Physics and Astronomy Laboratories

    ERIC Educational Resources Information Center

    Claycomb, J. R.

    2009-01-01

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

  1. Change of Collision Efficiency with Distance in Bacterial Transport Experiements

    SciTech Connect

    Dong, Hailiang; Scheibe, Timothy D.; Johnson, William P.; Monkman, Crystal; Fuller, Mark E.

    2006-05-01

    Previous bacterial transport studies have shown decreased bacterial adhesion with transport distance, largely based on laboratory core experiments. An inferred effect of microbial population variability is invoked to interpret experimental data, but there lacks direct measurement at field-scale, especially in correlation of transport distance with change of bacterial surface properties. This study was undertaken to determine change of collision efficiency with transport distance, taking advantage of the bacterial transport experiment in Oyster, VA in the summer of 2001. Upon injection of an adhesion deficient strain, Comamonas sp. DA001 into a up-gradient well, bacterial samples were taken from multi-level samplers along the flow path, and were injected into cores of 40 cm in length and 7.5 cm in diameter packed with homogenized sediment from the same site, South Oyster focus area (SOFA). Bacterial suspension samples were also measured for bacterial electrophoretic mobility distribution. Using filtration theory, collision efficiency, the probability of bacterial attachment to the grain surfaces upon collision and a quantitative measure of bacterial adhesion, was determined using CXTFIT model fitted attachment rate, measured grain size (10th percentile), porosity, flow velocity, and collector efficiency. Collision efficiency was also determined based on the fraction of retention in the cores. Contrary to previous results and interpretation of field-scale breakthrough curves, our experimentally determined collision efficiency increases with transport distance in the core experiments, which correlates with increasingly negative surface charge of the injected bacteria. Therefore we conclude that the apparent decrease in adhesion with transport distance in the field is strongly controlled by field-scale heterogeneity in physical and chemical aquifer properties and not by microbial population heterogeneity.

  2. Brownian motion - a laboratory experiment

    NASA Astrophysics Data System (ADS)

    Kruglak, Haym

    1988-09-01

    The availability of latex microspheres, compact television cameras and electronic calculators make it possible to perform an experiment on Brownian movement in one laboratory period. A more accurate value of N can be determined by other methods. However, the experiment described above has several valuable pedagogical outcomes. Undergraduate students get experience with several experimental techniques: (i) recording a `random walk' of a microphere; (ii) plotting a histogram of displacements; (iii) fitting a Gaussian curve to the histogram; (iv) checking the goodness of fit analytically or with probability graph paper; (v) calibrating screen displacements with a diffraction grating; (vi) calculating Avogadro's number from the experimental data; (vii) verifying data validity with the Einstein - Smoluchowski Law. The experiment also provides valuable practice in unit conversion and error analysis. Another instructive feature: the experiment makes the students aware of Einstein's work other than relativity. The students' reactions to the experiment were positive: `interesting', `challenging', `fun'.

  3. Laboratory Experiments on Magnetic Reconnection

    NASA Astrophysics Data System (ADS)

    Yamada, Masaaki

    2010-05-01

    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

  4. High charge state, ion-atom collision experiments using accel-decel

    SciTech Connect

    Bernstein, E.M.; Clark, M.W.; Tanis, J.A.; Graham, W.G.

    1987-01-01

    Recent studies of /sub 16/S/sup 13 +/ + He collisions between 2.5 and 200 MeV, which were made using the accel-decel technique with the Brookhaven National Laboratory coupled MP tandem Van de Graaff accelerators, are discussed. Cross sections were measured for single electron-capture and -loss as well as K x rays correlated to electron-capture. Other planned ion-atom collision experiments requiring accel-decel are also presented. 18 refs., 3 figs.

  5. Time-of-Flight Experiments in Molecular Motion and Electron-Atom Collision Kinematics

    ERIC Educational Resources Information Center

    Donnelly, Denis P.; And Others

    1971-01-01

    Describes a set of experiments for an undergraduate laboratory which demonstrates the relationship between velocity, mass, and temperature in a gas. The experimental method involves time-of-flight measurements on atoms excited to metastable states by electron impact. Effects resulting from recoil in the electron-atom collision can also be…

  6. Editorial: The Varieties of Laboratory Experience.

    ERIC Educational Resources Information Center

    Swartz, Cliff

    1984-01-01

    Briefly considers the nature of physics laboratories and their role in the physics curriculum. Also considers three valuable outcomes of laboratory experiences: using equipment, doing real experiments, and handling phenomena. (JN)

  7. Customized Laboratory Experience in Physical Chemistry

    ERIC Educational Resources Information Center

    Castle, Karen J.; Rink, Stephanie M.

    2010-01-01

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

  8. Customized Laboratory Experience in Physical Chemistry

    ERIC Educational Resources Information Center

    Castle, Karen J.; Rink, Stephanie M.

    2010-01-01

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

  9. Collision experiments between centimeter-sized protoplanetesimals in microgravity

    NASA Astrophysics Data System (ADS)

    Whizin, Akbar; Colwell, Joshua E.; Dove, Adrienne; Brisset, Julie; Cruz, Roberto; Foster, Zach

    2016-10-01

    In the early stages of planet formation in a protoplanetary disk the first coalescing bodies are weakly bound. Conditions in the disk, such as the presence of gas (drag), make further growth through centimeter and meter sized bodies difficult. For centimeter-sized aggregates self-gravity is almost non-existent and electrostatic surface forces such as van der Waals-type forces play a critical role in holding loosely bound rubble-piles together during their early formation. In order to understand how aggregates of this size grow we study the mechanical strengths, material, and collisional properties of cm-sized aggregates. The collisional outcomes between two aggregates can be determined by a set of definable collision parameters and experimental constraints on these parameters will aid in astrophysical models of planet formation. We have carried out a series of microgravity laboratory experiments in which we collide a pair of weakly bound aggregates together. In our free-fall chamber we collide two 3-cm aggregates together at collision velocities ranging from 50 to 220 cm/s and with pressure ~1 mbar. The aggregates are made of mm-sized silica bead particles and require internal cohesion to avoid fragmentation above modest collision speeds, which is supplied by adding H2O (later dehydrated) and between 0 - 0.1 g of a well-mixed liquid adhesive to simulate surface forces and bonds between particles. We measure the compressive strengths of the aggregates (0.5 - 10 kPa), find their coefficients of restitution (CoR), and determine their bouncing and fragmentation thresholds, over a range of velocities and internal strengths. We observed collisional outcomes such as bouncing, erosion (mass-loss), and fragmentation of the aggregates. We find the CoR of the aggregates to have a mean of 0.11 ± 0.1 with no dependence on velocity or strength. Impact velocities above ~2 m/s resulted in fragmentation of our aggregates, higher than the ~1 m/s threshold for porous dust aggregates

  10. Real-time collision avoidance in space: the GETEX experiment

    NASA Astrophysics Data System (ADS)

    Freund, Eckhard; Rossmann, Juergen; Schluse, Michael

    2000-10-01

    Intelligent autonomous robotic systems require efficient safety components to assure system reliability during the entire operation. Especially if commanded over long distances, the robotic system must be able to guarantee the planning of safe and collision free movements independently. Therefore the IRF developed a new collision avoidance methodology satisfying the needs of autonomous safety systems considering the dynamics of the robots to protect. To do this, the collision avoidance system cyclically calculates the actual collision danger of the robots with respect to all static and dynamic obstacles in the environment. If a robot gets in collision danger the methodology immediately starts an evasive action to avoid the collision and guides the robot around the obstacle to its target position. This evasive action is calculated in real-time in a mathematically exact way by solving a quadratic convex optimization problem. The secondary conditions of this optimization problem include the potential collision danger of the robots kinematic chain including all temporarily attached grippers and objects and the dynamic constraints of the robots. The result of the optimization procedure are joint accelerations to apply to prevent the robot from colliding and to guide it to its target position. This methodology has been tested very successfully during the Japanese/German space robot project GETEX in April 1999. During the mission, the collision avoidance system successfully protected the free flying Japanese robot ERA on board the satellite ETS-VII at all times. The experiments showed, that the developed system is fully capable of ensuring the safety of such autonomous robotic systems by actively preventing collisions and generating evasive actions in cases of collision danger.

  11. Fluid Flow Experiment for Undergraduate Laboratory.

    ERIC Educational Resources Information Center

    Vilimpochapornkul, Viroj; Obot, Nsima T.

    1986-01-01

    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)

  12. Fluid Flow Experiment for Undergraduate Laboratory.

    ERIC Educational Resources Information Center

    Vilimpochapornkul, Viroj; Obot, Nsima T.

    1986-01-01

    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)

  13. Multidimensional Screening as a Pharmacology Laboratory Experience.

    ERIC Educational Resources Information Center

    Malone, Marvin H.; And Others

    1979-01-01

    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…

  14. Simple Expalanation of a Well-Known Collision Experiment.

    ERIC Educational Resources Information Center

    Herrmann, F.; Schmalzle, P.

    1981-01-01

    Explains that the result of collision experiments with a linear arrangement of several identical elastic balls cannot be predicted solely from the conservation laws and energy and momentum. Indicates that the system of balls must be capable of dispersion-free energy propagation. (Author/JN)

  15. Laboratory and numerical study of intense envelope solitons of water waves: Generation, reflection from a wall, and collisions

    NASA Astrophysics Data System (ADS)

    Slunyaev, A.; Klein, M.; Clauss, G. F.

    2017-04-01

    The investigation of dynamics of intense solitary wave groups of collinear surface waves is performed by means of numerical simulations of the Euler equations and laboratory experiments. The processes of solitary wave generation, reflection from a wall, and collisions are considered. Steep solitary wave groups with characteristic steepness up to kAcr ≈ 0.3 (where k is the dominant wavenumber and Acr is the crest amplitude) are concerned. They approximately restore the structure after the interactions. In the course of the interaction with the wall and collisions, the maximum amplitude of the wave crests is shown to enhance up to 2.5 times. A standing-wave-like structure occurs in the vicinity of the wall, with certain locations of nodes and antinodes regardless the particular phase of the reflecting wave group. A strong asymmetry of the maximal wave groups due to an anomalous setup is shown in situations of collisions of solitons with different frequencies of the carrier. In some situations of head-on collisions, the amplitude of the highest wave is larger than in overtaking collisions of the same solitons. The discovered effects in interactions of intense wave groups are important in the context of mechanisms and manifestations of oceanic rogue waves.

  16. Laboratory Experience for Teaching Sensory Physiology

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  17. Laboratory Experience for Teaching Sensory Physiology

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  18. A Kinetic Experiment for the Biochemistry Laboratory.

    ERIC Educational Resources Information Center

    Palmer, Richard E.

    1986-01-01

    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)

  19. A Kinetic Experiment for the Biochemistry Laboratory.

    ERIC Educational Resources Information Center

    Palmer, Richard E.

    1986-01-01

    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)

  20. Chemical Reaction Experiment for the Undergraduate Laboratory.

    ERIC Educational Resources Information Center

    Kwon, K. C.; And Others

    1987-01-01

    Provides an overview of an experiment on reaction kinetics of the anthracene-hydrogen system. Includes a description of the laboratory equipment, procedures, and data analysis requirements. Points out the advantages of the recommended technique. (ML)

  1. Laboratory experiments on columnar jointing

    NASA Astrophysics Data System (ADS)

    Goehring, L.; Morris, S. W.

    2003-12-01

    The mechanism causing columnar jointing has remained an enticing mystery since the basalt columns of the Giant's Causeway in N. Ireland were first reported to science in the 17th century. This phenomenon, in which shrinkage cracks form a quasi-hexagonal arrangement, has been shown to produce columns in starch, glass, coal, sandstone, and ice, as well as in a variety of lava flows. This suggests that this pattern-forming process is very general in nature. However, most studies of columnar jointing have been confined to field studies of basalt flows. Following Muller, we have experimented with desiccating corn starch in an effort to understand this pattern from a more general point of view. The diffusion and evaporation of water in starch is thought to be analogous to the diffusion and extraction of heat from a basalt flow. By combining direct sampling and x-ray tomography, fully 3D descriptions of columnar jointing were obtained with starch samples. We have characterized the pattern with several statistical indices, which describe its structure and relative disorder. These methods can resolve the ordering of the colonnade near the free surface. We identified two distinct mechanisms by which the mean column area increases during pattern evolution. We found both a slow, almost power-law increase in column area, as well as episodes of sudden catastrophic jumps in scale. The latter suggests that the column scale is not a simple single-valued function of drying rate, but rather a metastable state subject to hysteresis. Such metastable behaviour might explain a fundamental question about columnar jointing -- why the columns are so regular in the direction of their growth. Moreover, these experiments may help discriminate between the various theoretical models of this pattern forming process. Finally, our results lead to predictions that could be tested by field measurements on basaltic colonnades.

  2. Subduction to Continental Delamination: Insights From Laboratory Experiments

    NASA Astrophysics Data System (ADS)

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

    2009-05-01

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

  3. Laboratory experience for teaching sensory physiology.

    PubMed

    Albarracín, Ana L; Farfán, Fernando D; Felice, Carmelo J

    2009-06-01

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

  4. Discovery & Interaction in Astro 101 Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Maloney, Frank Patrick; Maurone, Philip; DeWarf, Laurence E.

    2016-01-01

    The availability of low-cost, high-performance computing hardware and software has transformed the manner by which astronomical concepts can be re-discovered and explored in a laboratory that accompanies an astronomy course for arts students. We report on a strategy, begun in 1992, for allowing each student to understand fundamental scientific principles by interactively confronting astronomical and physical phenomena, through direct observation and by computer simulation. These experiments have evolved as :a) the quality and speed of the hardware has greatly increasedb) the corresponding hardware costs have decreasedc) the students have become computer and Internet literated) the importance of computationally and scientifically literate arts graduates in the workplace has increased.We present the current suite of laboratory experiments, and describe the nature, procedures, and goals in this two-semester laboratory for liberal arts majors at the Astro 101 university level.

  5. Value of Laboratory Experiments for Code Validations

    SciTech Connect

    Wawersik, W.R.

    1998-12-14

    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.

  6. Laser Mode Structure Experiments for Undergraduate Laboratories.

    ERIC Educational Resources Information Center

    Phillips, Richard A.; Gehrz, Robert D.

    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…

  7. Laboratory and Field Experiments in Motor Learning.

    ERIC Educational Resources Information Center

    Singer, Robert N.; And Others

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

  8. Ultrafiltration of Protein Solutions: A Laboratory Experiment

    ERIC Educational Resources Information Center

    Pansare, Vikram J.; Tien, Daniel; Prud'homme, Robert K.

    2015-01-01

    Biology is playing an increasingly important role in the chemical engineering curriculum. We describe a set of experiments we have implemented in our Undergraduate Laboratory course giving students practical insights into membrane separation processes for protein processing. The goal of the lab is to optimize the purification and concentration of…

  9. Laser Mode Structure Experiments for Undergraduate Laboratories.

    ERIC Educational Resources Information Center

    Phillips, Richard A.; Gehrz, Robert D.

    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…

  10. Ultrafiltration of Protein Solutions: A Laboratory Experiment

    ERIC Educational Resources Information Center

    Pansare, Vikram J.; Tien, Daniel; Prud'homme, Robert K.

    2015-01-01

    Biology is playing an increasingly important role in the chemical engineering curriculum. We describe a set of experiments we have implemented in our Undergraduate Laboratory course giving students practical insights into membrane separation processes for protein processing. The goal of the lab is to optimize the purification and concentration of…

  11. Laboratory experiments on arc deflection and instability

    SciTech Connect

    Zweben, S.; Karasik, M.

    2000-03-21

    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.

  12. Computer Based Simulation of Laboratory Experiments.

    ERIC Educational Resources Information Center

    Edward, Norrie S.

    1997-01-01

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

  13. Computer Based Simulation of Laboratory Experiments.

    ERIC Educational Resources Information Center

    Edward, Norrie S.

    1997-01-01

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

  14. Experiments and scaling laws for catastrophic collisions. [of asteroids

    NASA Technical Reports Server (NTRS)

    Fujiwara, A.; Cerroni, P.; Davis, D.; Ryan, E.; Di Martino, M.

    1989-01-01

    The existing data on shattering impacts are reviewed using natural silicate, ice, and cement-mortar targets. A comprehensive data base containing the most important parameters describing these experiments was prepared. The collisional energy needed to shatter consolidated homogeneous targets and the ensuing fragment size distributions have been well studied experimentally. However, major gaps exist in the data on fragment velocity and rotational distributions, as well as collisional energy partitioning for these targets. Current scaling laws lead to predicted outcomes of asteroid collisions that are inconsistent with interpretations of astronomical data.

  15. Experiments and scaling laws for catastrophic collisions. [of asteroids

    NASA Technical Reports Server (NTRS)

    Fujiwara, A.; Cerroni, P.; Davis, D.; Ryan, E.; Di Martino, M.

    1989-01-01

    The existing data on shattering impacts are reviewed using natural silicate, ice, and cement-mortar targets. A comprehensive data base containing the most important parameters describing these experiments was prepared. The collisional energy needed to shatter consolidated homogeneous targets and the ensuing fragment size distributions have been well studied experimentally. However, major gaps exist in the data on fragment velocity and rotational distributions, as well as collisional energy partitioning for these targets. Current scaling laws lead to predicted outcomes of asteroid collisions that are inconsistent with interpretations of astronomical data.

  16. The laboratory investigation of surface envelope solitons: reflection from a vertical wall and collisions of solitons

    NASA Astrophysics Data System (ADS)

    Slunyaev, Alexey; Klein, Marco; Clauss, Günther F.

    2016-04-01

    Envelope soliton solutions are key elements governing the nonlinear wave dynamics within a simplified theory for unidirectional weakly modulated weakly nonlinear wave groups on the water surface. Within integrable models the solitons preserve their structure in collisions with other waves; they do not disperse and can carry energy infinitively long. Steep and short soliton-like wave groups have been shown to exist in laboratory tests [1] and, even earlier, in numerical simulations [2, 3]. Thus, long-living wave groups may play important role in the dynamics of intense sea waves and wave-structure interactions. The solitary wave groups may change the wave statistics and can be taken into account when developing approaches for the deterministic forecasting of dangerous waves, including so-called rogue waves. An experimental campaign has been conducted in the wave basin of the Technical University of Berlin on simulations of intense solitary wave groups. The first successful experimental observation of intense envelope solitons took place in this facility [1]. The new experiments aimed at following main goals: 1) to reproduce intense envelope solitons with different carrier wave lengths; 2) to estimate the rate of envelope soliton dissipation; 3) to consider the reflection of envelope solitons on a vertical wall; 4) to consider head-on collisions of envelope solitons, and 5) to consider overtaking interactions of envelope solitons. Up to 9 wave gauges were used in each experimental run, which enabled registration of the surface movement at different distances from the wavemaker, at different locations across the wave flume and near the wall. Besides surface displacements, the group envelope shapes were directly recorded, with use of phase shifts applied to the modulated waves generated by the wavemaker. [1] A. Slunyaev, G.F. Clauss, M. Klein, M. Onorato, Simulations and experiments of short intense envelope solitons of surface water waves. Phys. Fluids 25, 067105

  17. Laboratory studies of atomic collision processes of importance in planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Stebbings, R. F.; Smith, K.

    1985-01-01

    A series of differential cross sections for angular scattering and charge transfer was measured. These studies employ position-sensitive detectors (PSD's) to collect collision products scattered over a wide range of angles; and the research program includes investigation of differential cross sections for total angular scattering, charge transfer, stripping, and other collisions. All of these processes can be studied with the same basic apparatus, but minor modifications in the equipment details and in the data acquisition programs and techniques are required for each individual experiment.

  18. Tyurin with TRAC experiment in Destiny laboratory

    NASA Image and Video Library

    2007-01-02

    ISS014-E-11047 (2 Jan. 2007) --- Cosmonaut Mikhail Tyurin, Expedition 14 flight engineer representing Russia's Federal Space Agency, works with the Test of Reaction and Adaptation Capabilities (TRAC) experiment in the Destiny laboratory of the International Space Station. The TRAC investigation will test the theory of brain adaptation during space flight by testing hand-eye coordination before, during and after the space flight.

  19. Systems integration test laboratory application & experiences

    NASA Astrophysics Data System (ADS)

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

    1991-01-01

    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

  20. Monitoring hydraulic fracture growth: Laboratory experiments

    SciTech Connect

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

    2000-04-01

    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.

  1. The BDX experiment at Jefferson Laboratory

    SciTech Connect

    Celentano, Andrea

    2015-06-01

    The existence of MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. The Beam Dump eXperiment (BDX) at Jefferson Laboratory aims to investigate this mass range. Dark matter particles will be detected through scattering on a segmented, plastic scintillator detector placed downstream of the beam-dump at one of the high intensity JLab experimental Halls. The experiment will collect up to 1022 electrons-on-target (EOT) in a one-year period. For these conditions, BDX is sensitive to the DM-nucleon elastic scattering at the level of a thousand counts per year, and is only limited by cosmogenic backgrounds. The experiment is also sensitive to DM-electron elastic and inelastic scattering, at the level of 10 counts/year. The foreseen signal for these channels is a high-energy (> 100 MeV) electromagnetic shower, with almost no background. The experiment has been presented in form of a Letter of Intent to the laboratory, receiving positive feedback, and is currently being designed.

  2. Experience of maintaining laboratory educational website's sustainability

    PubMed Central

    Dimenstein, Izak B.

    2016-01-01

    Laboratory methodology websites are specialized niche websites. The visibility of a niche website transforms it into an authority site on a particular “niche of knowledge.” This article presents some ways in which a laboratory methodology website can maintain its sustainability. The optimal composition of the website includes a basic content, a blog, and an ancillary part. This article discusses experimenting with the search engine optimization query results page. Strategic placement of keywords and even phrases, as well as fragmentation of the post's material, can improve the website's visibility to search engines. Hyperlinks open a chain reaction of additional links and draw attention to the previous posts. Publications in printed periodicals are a substantial part of a niche website presence on the Internet. Although this article explores a laboratory website on the basis of our hands-on expertise maintaining “Grossing Technology in Surgical Pathology” (www.grossing-technology.com) website with a high volume of traffic for more than a decade, the recommendations presented here for developing an authority website can be applied to other professional specialized websites. The authority websites visibility and sustainability are preconditions for aggregating them in a specialized educational laboratory portal. PMID:27688928

  3. Controlled Space Physics Experiments using Laboratory Magnetospheres

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  4. Experience of maintaining laboratory educational website's sustainability.

    PubMed

    Dimenstein, Izak B

    2016-01-01

    Laboratory methodology websites are specialized niche websites. The visibility of a niche website transforms it into an authority site on a particular "niche of knowledge." This article presents some ways in which a laboratory methodology website can maintain its sustainability. The optimal composition of the website includes a basic content, a blog, and an ancillary part. This article discusses experimenting with the search engine optimization query results page. Strategic placement of keywords and even phrases, as well as fragmentation of the post's material, can improve the website's visibility to search engines. Hyperlinks open a chain reaction of additional links and draw attention to the previous posts. Publications in printed periodicals are a substantial part of a niche website presence on the Internet. Although this article explores a laboratory website on the basis of our hands-on expertise maintaining "Grossing Technology in Surgical Pathology" (www.grossing-technology.com) website with a high volume of traffic for more than a decade, the recommendations presented here for developing an authority website can be applied to other professional specialized websites. The authority websites visibility and sustainability are preconditions for aggregating them in a specialized educational laboratory portal.

  5. Threshold collision induced dissociation experiment for azobenzene and its derivatives

    NASA Astrophysics Data System (ADS)

    Rezaee, Mohammadreza; Compton, Robert

    In this study we investigated protonated azobenzene cation and properties of trans 2,2',6,6'-tetrafluoroazobenzene anion using the collision induced dissociation method and the results are compared with the results from ab initio electronic structure calculations. We measured the bond dissociation energies experimentally and found which theoretical quantum chemistry methods yield best results. Several high accuracy multi-level calculations such as CBS-QB3, G3 and G4 had been carried out to obtain reliable thermochemical information for azobenzene and several of its derivatives and their anion or cation. We also performed other experiments such as Raman spectroscopy to study these light sensitive molecules with promising applications such as photo-switching.

  6. Production of defects in metals by collision cascades: TEM experiments

    SciTech Connect

    Kirk, M.A.

    1995-03-01

    This paper reviews experimental TEM data on production of dislocation loops by low energy ion bombardment to low doses, as simulations of similar collision cascades produced by fast neutron irradiation, in various metals and alloys. The dependence of vacancy dislocation loop formation on recoil energy, sample temperature, and specific metal or alloy will be examined. Special emphasis will be placed on the effects of dilute alloy additions. A model for cascade melting will be employed to understand these effects, and will require an examination of the role of electron-phonon coupling in cascade cooling and recrystallization. The formation of interstitial dislocation loops as cascade defects, and the influence of the nearby surfaces in these experiments is briefly discussed.

  7. Laboratory experiments from the toy store

    NASA Technical Reports Server (NTRS)

    Mcclelland, H. T.

    1992-01-01

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

  8. Optimizing Laboratory Experiments for Dynamic Astrophysical Phenomena

    SciTech Connect

    Ryutov, D; Remington, B

    2005-09-13

    To make a laboratory experiment an efficient tool for the studying the dynamical astrophysical phenomena, it is desirable to perform them in such a way as to observe the scaling invariance with respect to the astrophysical system under study. Several examples are presented of such scalings in the area of magnetohydrodynamic phenomena, where a number of scaled experiments have been performed. A difficult issue of the effect of fine-scale dissipative structures on the global scale dissipation-free flow is discussed. The second part of the paper is concerned with much less developed area of the scalings relevant to the interaction of an ultra-intense laser pulse with a pre-formed plasma. The use of the symmetry arguments in such experiments is also considered.

  9. Impact fracture experiments simulating interstellar grain-grain collisions

    NASA Technical Reports Server (NTRS)

    Freund, Friedemann; Chang, Sherwood; Dickinson, J. Thomas

    1990-01-01

    Oxide and silicate grains condensing during the early phases of the formation of the solar system or in the outflow of stars are exposed to high partial pressures of the low-z elements H, C, N and O and their simple gaseous compounds. Though refractory minerals are nominally anhydrous and non-carbonate, if they crystallize in the presence of H2O, N2 and CO or CO2 gases, they dissolve traces of the gaseous components. The question arises: How does the presence of dissolved gases or gas components manifest itself when grain-grain collisions occur. What are the gases emitted when grains are shattered during a collision event. Researchers report on fracture experiments in ultrahigh vacuum (UHV, approximately less than 10 to the -8th power mbar) designed to measure (by means of a quadrupole mass spectrometer, QMS, with microns to ms time resolution) the emission of gases and vapors during and after impact (up to 1.5 sec). Two terrestrial materials were chosen which represent structural and compositional extremes: olivine (San Carlos, AZ), a densely packed Mg-Fe(2+) silicate from the upper mantle, available as 6 to 12 mm single crystals, and obsidian (Oregon), a structurally open, alkaline-SiO2-rich volcanic glass. In the olivine crystals OH- groups have been identified spectroscopically, as well as H2 molecules. Obsidian is a water-rich glass containing OH- besides H2O molecules. Olivine from the mantle often contains CO2, either as CO2-rich fluid in fluid inclusions or structurally dissolved or both. By analogy to synthetic glasses CO2 in the obsidian may be present in form of CO2 molecules in voids of molecular dimensions, or as carbonate anions, CO3(2-). No organic molecules have been detected spectroscopically in either material. Results indicate that refractory oxide/silicates which contain dissolved traces of the H2O and CO/CO2 components but no spectroscopically detectable traces of organics may release complex H-C-O (possibly H-C-N-O) molecules upon fracture

  10. Impact fracture experiments simulating interstellar grain-grain collisions

    NASA Technical Reports Server (NTRS)

    Freund, Friedemann; Chang, Sherwood; Dickinson, J. Thomas

    1990-01-01

    Oxide and silicate grains condensing during the early phases of the formation of the solar system or in the outflow of stars are exposed to high partial pressures of the low-z elements H, C, N and O and their simple gaseous compounds. Though refractory minerals are nominally anhydrous and non-carbonate, if they crystallize in the presence of H2O, N2 and CO or CO2 gases, they dissolve traces of the gaseous components. The question arises: How does the presence of dissolved gases or gas components manifest itself when grain-grain collisions occur. What are the gases emitted when grains are shattered during a collision event. Researchers report on fracture experiments in ultrahigh vacuum (UHV, approximately less than 10 to the -8th power mbar) designed to measure (by means of a quadrupole mass spectrometer, QMS, with microns to ms time resolution) the emission of gases and vapors during and after impact (up to 1.5 sec). Two terrestrial materials were chosen which represent structural and compositional extremes: olivine (San Carlos, AZ), a densely packed Mg-Fe(2+) silicate from the upper mantle, available as 6 to 12 mm single crystals, and obsidian (Oregon), a structurally open, alkaline-SiO2-rich volcanic glass. In the olivine crystals OH- groups have been identified spectroscopically, as well as H2 molecules. Obsidian is a water-rich glass containing OH- besides H2O molecules. Olivine from the mantle often contains CO2, either as CO2-rich fluid in fluid inclusions or structurally dissolved or both. By analogy to synthetic glasses CO2 in the obsidian may be present in form of CO2 molecules in voids of molecular dimensions, or as carbonate anions, CO3(2-). No organic molecules have been detected spectroscopically in either material. Results indicate that refractory oxide/silicates which contain dissolved traces of the H2O and CO/CO2 components but no spectroscopically detectable traces of organics may release complex H-C-O (possibly H-C-N-O) molecules upon fracture

  11. Controlled Space Physics Experiments using Laboratory Magnetospheres

    NASA Astrophysics Data System (ADS)

    Mauel, Michael; Davis, M.; Garnier, D.; Roberts, T. M.; Worstell, M.; Kesner, J.

    2013-10-01

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

  12. Newton's cradle undone: Experiments and collision models for the normal collision of three solid spheres

    NASA Astrophysics Data System (ADS)

    Donahue, C. M.; Hrenya, C. M.; Zelinskaya, A. P.; Nakagawa, K. J.

    2008-11-01

    Using an apparatus inspired by Newton's cradle, the simultaneous, normal collision between three solid spheres is examined. Namely, an initially touching, motionless pair of "target" particles (doublet) is impacted on one end by a third "striker" particle. Measurements of postcollisional velocities and collision durations are obtained via high-speed photography and an electrical circuit, respectively. Contrary to intuition, the expected Newton's cradle outcome of a motionless, touching particle pair at the bottom of the pendulum arc is not observed in either case. Instead, the striker particle reverses its direction and separates from the middle particle after collision. This reversal is not observed, however, if the target particles are separated by a small distance (not in contact) initially, although a separation still occurs between the striker and middle particle after the collision, with both particles traveling in the same direction. For the case of initially touching target particles, contact duration measurements indicate that the striker separates from the three particles before the two target particles separate. However, when the targets are slightly separated, a three-particle collision is never observed, and the collision is, in fact, a series of two-body collisions. A subsequent implementation of a variety of hard-sphere and soft-sphere collision models indicates that a three-body (soft-sphere) treatment is essential for predicting the velocity reversal, consistent with the experimental findings. Finally, a direct comparison between model predictions and measurements of postcollisional velocities and contact durations provides a gauge of the relative merits of existing collision models for three-body interactions.

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

    ERIC Educational Resources Information Center

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

    2003-01-01

    Dicusses the effects of using laboratory assistants for disabled students' learning in the chemistry laboratory. Presents two case studies and general strategies for approaching laboratory experiences for disabled students. (KHR)

  14. Validating the Collision-Dominated Child-Langmuir Law for a DC Discharge Cathode Sheath in an Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Lisovskiy, V.; Yegorenkov, V.

    2009-01-01

    In this paper, we propose a simple method of observing the collision-dominated Child-Langmuir law in the course of an undergraduate laboratory work devoted to studying the properties of gas discharges. To this end we employ the dc gas discharge whose properties are studied in sufficient detail. The undergraduate laboratory work itself is reduced…

  15. Validating the Collision-Dominated Child-Langmuir Law for a DC Discharge Cathode Sheath in an Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Lisovskiy, V.; Yegorenkov, V.

    2009-01-01

    In this paper, we propose a simple method of observing the collision-dominated Child-Langmuir law in the course of an undergraduate laboratory work devoted to studying the properties of gas discharges. To this end we employ the dc gas discharge whose properties are studied in sufficient detail. The undergraduate laboratory work itself is reduced…

  16. Laboratory Experiments of Rip Current Generation

    NASA Astrophysics Data System (ADS)

    Garnier, R.; Coco, G.; Lomonaco, P.; Dalrymple, R. A.; Alvarez, A.; Gonzalez, M.; Medina, R.

    2014-12-01

    The hypothesis of rip current generation from purely hydrodynamic processes is here investigated through laboratory experiments. The experiments have been performed at the Cantabria Coastal and Ocean Basin (CCOB) with a segmented wavemaker consisting of 64 waveboards. The basin measures 25m in the cross-shore and 32m in the alongshore direction and the water depth at the wavemaker is 1m. A concrete plane sloping (1:5) beach has been built in the opposite side of the wave machine, its toe is 15m from the waveboards. Reflective lateral walls covered the full length of the basin. The set of instruments consists of 33 wave gauges deployed along two longshore and two cross-shore transects, 7 acoustic Doppler velocimeters and 15 run-up wires. Furthermore a set of two cameras has been synchronized with the data acquisition system. Two types of experiments have been performed to specifically study the generation of rip currents under wave group forcing. First, similarly to the experiments of Fowler and Dalrymple (Proc. 22nd Int. Conf. Coast. Eng.,1990), two intersecting wave trains with opposite directions have been imposed. They give rise to the formation of a non-migrating rip current system with a wavelength that depends on wave frequency and direction. Second, single wave trains with alongshore periodic amplitude attenuation have been imposed. Although the attenuation has been set such that the incident wave field has the same envelope as in the first type of experiments, the rip current system differs due to diffraction and interference processes. The results for different wave conditions (maximum incident wave height from 0.2m to 0.4m, wave period from 1.4s to 2s) will be presented and the intensity of the rip currents will be compared to the alongshore variation in wave set-up. This research is part of the ANIMO project funded by the Spanish Government under contract BIA2012-36822.

  17. Turbulent flows and intermittency in laboratory experiments

    NASA Astrophysics Data System (ADS)

    Anselmet, F.; Antonia, R. A.; Danaila, L.

    2001-10-01

    In turbulent flows, the transfer of energy from large to small scales is strongly intermittent, in contradiction with Kolmogorov's (Dokl. Akad. Nauk. SSSR 30 (1941) 299; hereafter K41) assumptions. The statistical properties associated with these energy transfer fluctuations at a given scale r have been widely studied theoretically, experimentally and numerically over the last 30 years or so. Such fluctuations are also encountered in various Planetary and Space Science domains. The present paper presents a review of laboratory experiments which clearly display the fractal nature of the (spatial or temporal) energy distribution at scale r, the departures from the K41 predictions being generally quantified through high-order moments of velocity increments.

  18. Experiment definition phase shuttle laboratory LDRL-10.6 experiment

    NASA Technical Reports Server (NTRS)

    1975-01-01

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

  19. Sensor-Based Collision Avoidance: Theory and Experiments

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun; Steele, Robert; Ivlev, Robert

    1996-01-01

    A new on-line control strategy for sensor-based collision avoidance of manipulators and supporting experimental results are presented in this article. This control strategy is based on nullification of virtual forces applied to the end-effector by a hypothetical spring-plus-damper attached to the object's surface. In the proposed approach, the real-time arm control software continuously monitors the object distance measured by the arm-mounted proximity sensors. When this distance is less than a preset threshold, the collision avoidance control action is initiated to inhibit motion toward the object and thus prevent collision. This is accomplished by employing an outer feedback loop to perturb the end-effector nominal motion trajectory in real-time based on the sensory data. The perturbation is generated by a proportional-plus-integral (PI) collision avoidance controller acting on the difference between the sensed distance and the preset threshold. This approach is computationally very fast, requires minimal modification to the existing manipulator positioning system, and provides the manipulator with an on-line collision avoidance capability to react autonomously and intelligently. A dexterous RRC robotic arm is instrumented with infrared proximity sensors and is operated under the proposed collision avoidance strategy. Experimental results are presented to demonstrate end-effector collision avoidance both with an approaching object and while reaching inside a constricted opening.

  20. A novel molecular synchrotron for cold collision and EDM experiments

    PubMed Central

    Hou, Shunyong; Wei, Bin; Deng, Lianzhong; Yin, Jianping

    2016-01-01

    Limited by the construction demands, the state-of-the-art molecular synchrotrons consist of only 40 segments that hardly make a good circle. Imperfections in the circular structure will lead to the appearance of unstable velocity regions (i.e. stopbands), where molecules of certain forward velocity will be lost from the structure. In this paper, we propose a stopband-free molecular synchrotron. It contains 1570 ring electrodes, which nearly make a perfect circle, capable of confining both light and heavy polar molecules in the low-field-seeking states. Molecular packets can be conveniently manipulated with this synchrotron by various means, like acceleration, deceleration or even trapping. Trajectory calculations are carried out using a pulsed 88SrF molecular beam with a forward velocity of 50 m/s. The results show that the molecular beam can make more than 500 round trips inside the synchrotron with a 1/e lifetime of 6.2 s. The synchrotron can find potential applications in low-energy collision and reaction experiments or in the field of precision measurements, such as the searches for electric dipole moment of elementary particles. PMID:27600539

  1. Centrality determination in heavy-ion collisions with the CBM experiment

    NASA Astrophysics Data System (ADS)

    Klochkov; Selyuzhenkov, I.; CBM collaboration

    2017-01-01

    The size and evolution of the medium created in a heavy-ion collision depends on collision geometry. Experimentally collisions can be characterized by the measured particle multiplicities around midrapidity or by the energy measured in the forward rapidity region, which is sensitive to the spectator fragments. In the Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) the multiplicity of produced particles is measured with the silicon tracking system (STS). The projectile spectator detector (PSD) measures the energy of spectator fragments. We present the procedure of collision centrality determination in CBM and its performance using the PSD and the STS information.

  2. Estimates of the collision symmetry planes in HADES experiment at GSI

    NASA Astrophysics Data System (ADS)

    Zaytsev, A. S.; Selyuzhenkov, I.

    2017-01-01

    Estimate of the collision symmetry planes is a crucial part of the anisotropic flow analysis in heavy-ion collisions. HADES experiment at GSI has different possibilities for symmetry plane estimation. In this letter different methods of the symmetry plane resolution calculation are compared and the differences are explained in terms of non-flow contribution.

  3. Transit bus operator performance and attitudes toward a collision warning system: results of a simulator experiment.

    PubMed

    Reinach, Stephen J; Everson, Jeffrey H

    2005-09-01

    This article discusses the results of a simulator experiment to examine the efficacy of a collision warning system for transit bus operators. Bus operators from a major metropolitan transit agency were assigned to one of three conditions: a collision warning system with a visual-only driver-vehicle interface, a collision warning system with a visual and auditory driver-vehicle interface, or no collision warning system (baseline). Operators were exposed to a critical event at the end of the simulation, in which a vehicle suddenly stopped in front of the bus while the operator was distracted by an in-vehicle task. Upon completing the experiment, operators who used the collision warning system were asked about their experience using the system, as well as whether or not they would like such a system in real life. Experimental results revealed new information about transit bus operator performance, but indicated no statistically significant differences among the three conditions. Subjective data indicated that operators had a positive attitude toward collision warning system usage. Operators generally liked the collision warning system and felt that a system such as the one used in the experiment would help them in avoiding crashes in the real world. These findings suggest that a collision warning system for transit bus operators is feasible from the perspective of user acceptance. However, several technical areas still need to be resolved.

  4. Laboratory experiments of salt water intrusion

    NASA Astrophysics Data System (ADS)

    Crestani, Elena; Camporese, Matteo; Salandin, Paolo

    2015-04-01

    The problem of saltwater intrusion in coastal aquifers is dealt with by the proper setup of a sand-box device to develop laboratory experiments in a controlled environment. Saline intrusion is a problem of fundamental importance and affects the quality of both surface water and groundwater in coastal areas. In both cases the phenomenon may be linked to anthropogenic (construction of reservoirs, withdrawals, etc.) and/or natural (sea-level excursions, variability of river flows, etc.) changes. In recent years, the escalation of this problem has led to the development of specific projects and studies to identify possible countermeasures, typically consisting of underground barriers. Physical models are fundamental to study the saltwater intrusion problem, since they provide benchmarks for numerical model calibrations and for the evaluation of the effectiveness of solutions to contain the salt wedge. In order to study and describe the evolution of the salt wedge, the effectiveness of underground barriers, and the distance from the coast of a withdrawal that guarantees a continuous supply of fresh water, a physical model has been realized at the University of Padova to represent the terminal part of a coastal aquifer. It consists of a laboratory flume 500 cm long, 30 cm wide and 60 cm high, filled for an height of 45 cm with glass beads with a d50 of 0.6 mm and a uniformity coefficient d60/d10~= 1.5. The material is homogeneous and characterized by a porosity of about 0.37 and by an hydraulic conductivity of about 1.8×10-3 m/s. Upstream from the sand-box, a tank, continuously supplied by a pump, provides fresh water to recharge the aquifer, while the downstream tank, filled with salt water, simulates the sea. The volume of the downstream tank (~= 2 m3) is about five times the upstream one, so that density variations due to the incoming fresh water flow are negligible. The water level in the two tanks is continuously monitored by means of two level probes and is

  5. Plume Electrification: Laboratory and Numerical Experiments

    NASA Astrophysics Data System (ADS)

    Mendez, J. S.; Dufek, J.

    2012-12-01

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

  6. Magnetized laboratory plasma jets: experiment and simulation.

    PubMed

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

    2015-01-01

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

  7. Organic Laboratory Experiments: Micro vs. Conventional.

    ERIC Educational Resources Information Center

    Chloupek-McGough, Marge

    1989-01-01

    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)

  8. Organic Laboratory Experiments: Micro vs. Conventional.

    ERIC Educational Resources Information Center

    Chloupek-McGough, Marge

    1989-01-01

    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)

  9. Simulating Astrophysical Jets in Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Bellan, Paul

    2004-11-01

    A laboratory plasma configuration based on spheromak [1] magnetic fusion plasma physics technology is used to simulate many important features of magnetically driven astrophysical jets. The experimental sequence starts with a quasi-static seed poloidal magnetic field that links a central disk electrode to a co-planar bounding annular electrode; this arrangement provides a topology analogous to the poloidal magnetic field of a star linking a surrounding accretion disk. After puffing neutral gas from nozzles mounted on the electrodes, plasma is created via application of a large emf between the central disk and the bounding annular electrode. The emf then drives a large poloidal electric current flowing from the central disk electrode (star) to the annulus (accretion disk) along the bias poloidal magnetic field. This electric current produces large magnetohydrodynamic forces which result in dynamics analogous to the dynamics of an astrophysical jet. In particular, the laboratory "astrophysical jet" is observed [2,3] to evolve through a distinct, reproducible sequence consisting of jet formation, collimation, kink instability, and for appropriate parameters, detachment into an unbounded, expanding spheromak-like plasmoid. These observations and related observations on a solar prominence simulation experiment [4] have motivated an analytic model [5] for the collimation physics whereby stagnation of convected, frozen-in toroidal magnetic flux amplifies the toroidal magnetic flux density and then, since the toroidal magnetic field (i.e., toroidal flux density) provides the pinch force, the pinch force is increased, collimating the jet. The following talk (You, Bellan, Yun) will present detailed measurements of the jet formation, acceleration, and collimation process. [1] P. M. Bellan, Spheromaks (Imperial College Press, London, 2000). [2] S. C. Hsu and P. M. Bellan, Mon. Not. R. Astron. Soc. 334, 257 (2002). [3] S. C. Hsu and P. M. Bellan, Phys. Rev. Letters 90, article

  10. Experiment definition phase shuttle laboratory. LDRL-10.6 experiment

    NASA Technical Reports Server (NTRS)

    1976-01-01

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

  11. Electron beam injection experiments - Replication of flight observations in a laboratory beam plasma discharge

    NASA Technical Reports Server (NTRS)

    Bernstein, W.; Mcgarity, J. O.; Konradi, A.

    1983-01-01

    Recent electron beam injection experiments in the lower ionosphere have produced two perplexing results: (1) At altitudes from 140 km to 220 km, the beam associated 391.4 nm intensity is relatively independent of altitude despite the decreasing N2 abundance. (2) The radial extent of the perturbed region populated by beam associated energetic electrons significantly exceeds the nominal gyrodiameter for 90 deg injection. A series of laboratory measurements is described in which both of these flight results appear to have been closely reproduced. The laboratory results are reasonably consistent with the transition from a collision dominated to collisionless beam-plasma discharge configuration.

  12. First experiments probing the collision of parallel magnetic fields using laser-produced plasmas

    SciTech Connect

    Rosenberg, M. J.; Li, C. K.; Fox, W.; Igumenshchev, I.; Seguin, F. H.; Town, R. P.; Frenje, J. A.; Stoeckl, C.; Glebov, V.; Petrasso, R. D.

    2015-04-08

    Novel experiments to study the strongly-driven collision of parallel magnetic fields in β~10, laser-produced plasmas have been conducted using monoenergetic proton radiography. These experiments were designed to probe the process of magnetic flux pileup, which has been identified in prior laser-plasma experiments as a key physical mechanism in the reconnection of anti-parallel magnetic fields when the reconnection inflow is dominated by strong plasma flows. In the present experiments using colliding plasmas carrying parallel magnetic fields, the magnetic flux is found to be conserved and slightly compressed in the collision region. Two-dimensional (2D) particle-in-cell (PIC) simulations predict a stronger flux compression and amplification of the magnetic field strength, and this discrepancy is attributed to the three-dimensional (3D) collision geometry. Future experiments may drive a stronger collision and further explore flux pileup in the context of the strongly-driven interaction of magnetic fields.

  13. First experiments probing the collision of parallel magnetic fields using laser-produced plasmas

    SciTech Connect

    Rosenberg, M. J. Li, C. K.; Séguin, F. H.; Frenje, J. A.; Petrasso, R. D.; Fox, W.; Igumenshchev, I.; Stoeckl, C.; Glebov, V.; Town, R. P. J.

    2015-04-15

    Novel experiments to study the strongly-driven collision of parallel magnetic fields in β ∼ 10, laser-produced plasmas have been conducted using monoenergetic proton radiography. These experiments were designed to probe the process of magnetic flux pileup, which has been identified in prior laser-plasma experiments as a key physical mechanism in the reconnection of anti-parallel magnetic fields when the reconnection inflow is dominated by strong plasma flows. In the present experiments using colliding plasmas carrying parallel magnetic fields, the magnetic flux is found to be conserved and slightly compressed in the collision region. Two-dimensional (2D) particle-in-cell simulations predict a stronger flux compression and amplification of the magnetic field strength, and this discrepancy is attributed to the three-dimensional (3D) collision geometry. Future experiments may drive a stronger collision and further explore flux pileup in the context of the strongly-driven interaction of magnetic fields.

  14. Studies of relativistic heavy ion collisions at the AGS (Experiment 814)

    SciTech Connect

    Cleland, W.E.

    1992-01-01

    During the past year, the Pittsburgh group has continued to work with the E814 collaboration in carrying out AGS Experiment 814. We present here a brief history of the experiment, followed by a detailed report of the analysis work being pursued at the University of Pittsburgh. As originally proposed, Experiment 814 is a study of both extreme peripheral collisions and the transition from peripheral to central collisions in relativistic heavy ion-nucleus interactions. We are studying relativistic heavy ion interactions with nuclei in two types of collisions: (a) extreme peripheral collisions of large impact parameter, and (b) central collisions with high transverse energy in the final state. The experiment emphasizes the measurement of overall event characteristics, in particular energy flow measurements and a precise measurement of the particle charge, momentum, and energy in the forward direction. This permits measurements of cross sections and rapidity densities as a function of the transverse energy for leading baryons emitted into regions of larger rapidity. Combining the energy flow measurements as a function of rapidity with the spectra of leading baryons provides information on the impact parameter dependence of the nuclear stopping of the projectile in relativistic heavy ion collisions. In 1988, the scope of Experiment 814 was enlarged to include a search for strange matter in central collisions, the first results of which have been published, and analysis on a longer run taken in 1990 is still under way.

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

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  16. Solitons Experience for Black Hole Production in Ultrarelativistic Particle Collisions

    NASA Astrophysics Data System (ADS)

    Aref'eva, I. Ya.

    2013-06-01

    We discuss the analogy between soliton scattering in quantum field theory and black hole/wormholes (BH/WH) production in ultrarelativistic particle collisions in gravity. It is a common wisdom of the current paradigm suggests that BH/WH formation in particles collisions will happen when a center-mass energy of colliding particles is sufficiently above the Planck scale (the transplanckian region) and the BH/WH production can be estimated by the classical geometrical cross section. We compare the background of this paradigm with the functional integral method to scattering amplitudes and, in particular, we stress the analogy of the BH production in collision of ultrarelativistic particle and appearance of breathers poles in the scattering amplitudes in the Sin-Gordon model.

  17. Solitons Experience for Black Hole Production in Ultrarelativistic Particle Collisions

    NASA Astrophysics Data System (ADS)

    Ya. Aref'eva, I.

    2012-11-01

    We discuss the analogy between soliton scattering in quantum field theory and black hole/wormholes (BH/WH) production in ultrarelativistic particle collisions in gravity. It is a common wisdom of the current paradigm suggests that BH/WH formation in particles collisions will happen when a center-mass energy of colliding particles is sufficiently above the Planck scale (the transplanckian region) and the BH/WH production can be estimated by the classical geometrical cross section. We compare the background of this paradigm with the functional integral method to scattering amplitudes and, in particular, we stress the analogy of the BH production in collision of ultrarelativistic particle and appearance of breathers poles in the scattering amplitudes in the Sin-Gordon model.

  18. Laboratory High-velocity, Laser-Driven, Magnetized, Collision-less Flows

    NASA Astrophysics Data System (ADS)

    Pepin, Henri; Higginson, D.; Korneev, Ph.; Beard, J.; Chen, S. N.; Grech, M.; Gremillet, L.; D'Humières, E.; Pikuz, S.; Pollock, B.; Ruyer, C.; Riquier, R.; Fuchs, J.

    2015-11-01

    Understanding the mechanism leading to the acceleration of cosmic-ray particles up to extremely high-energies is an outstanding problem in astrophysics. This acceleration is thought to be linked to the collision-less shocks formed by the collision of energetic magnetized astrophysical outflows such as supernovae remnants and gamma-ray bursts. To gain insight on these particle accelerators, we have performed experiments on the Titan laser (60J/beam, 650fs). By irradiating opposing targets we launch two counter-streaming beams, embedded in an external 20T B-field. We observe a density increase in the middle of the streams and a proton acceleration at double the energy without external field. Particle-in-cell simulations show that the expansion of the beams causes a compression of the external B-field up to 500T, which is strong enough to reflect electrons from the strong field region. This creates a charge-separation and causes the development of strong E-fields which accelerates the ions at large energies, consistent with the experiment.

  19. Numerical Geodynamic Experiments of Continental Collision: Past and Present

    NASA Astrophysics Data System (ADS)

    Gray, Robert

    Research explores deep continental lithosphere (i.e., the continental lower crust and mantle lithosphere) deformation during continental collision. I found that depending on the composition/rheology of the crust and the amount of radiogenic heat production in the crust, three dominant modes of mantle lithosphere deformation evolve under Neoarchean-like conditions: (1) a pure-shear thickening style; (2) an imbrication style; (3) and a "flat-subduction" style. The imbrication and the flat-subduction styles result in the emplacement of "plate-like" mantle lithosphere at depths between 200 km and 325 km. The imbrication style behavior shifts to the "flat-subduction" style behavior after a crustal inversion event. I investigated mature Phanerozoic-style collision and found that it is sensitive to mantle lithosphere density, mantle lithosphere yield stress, lower-crustal strength and to the presence of phase change-related density changes in the lower crust. The early stages of collision are accommodated by subduction of lower crust and mantle lithosphere along a discrete shear zone beneath the overriding plate. Next, the subducting lower crust and mantle lithosphere retreat from the collision zone, permitting the sub-lithospheric mantle to upwell and intrude the overriding plate. Next, the lower crust and mantle lithosphere of the overriding plate delaminate from the overlying crust. This process produces plateau-like uplift. These modeling results are interpreted in the context of available geological and geophysical observables for the Himalayan-Tibetan orogen. I quantitatively investigated the effects that sediment deposition may have on continental lithosphere deformation during collision. In the absence of sedimentation, the early stages of collision are accommodated by subduction of lower crust and mantle lithosphere beneath the overriding plate. Next, the subducting lower crust and mantle lithosphere retreat from the collision zone. This permits the sub

  20. Ethics skills laboratory experience for surgery interns.

    PubMed

    Moon, Margaret R; Hughes, Mark T; Chen, Jiin-Yu; Khaira, Kiran; Lipsett, Pamela; Carrese, Joseph A

    2014-01-01

    Ethics curricula are nearly universal in residency training programs, but the content and delivery methods are not well described, and there is still a relative paucity of literature evaluating the effect of ethics curricula. Several commentators have called for more ethics curriculum development at the postgraduate level, and specifically in surgery training. We detail our development and implementation of a clinical ethics curriculum for surgery interns. We developed curricula and simulated patient cases for 2 core clinical ethics skills--breaking bad news and obtaining informed consent. Educational sessions for each topic included (1) framework development (discussion of interns' current experience, development of a consensus framework for ethical practice, and comparison with established frameworks) and (2) practice with simulated patient followed by peer and faculty feedback. At the beginning and end of each session, we administered a test of confidence and knowledge about the topics to assess the effect of the sessions. A total of 98 surgical interns participated in the ethics skills laboratory from Spring 2008 to Spring 2011. We identified significant improvement in confidence regarding the appropriate content of informed consent (<0.001) and capacity to break bad news (<0.001). We also identified significant improvement in overall knowledge regarding informed consent (<0.01), capacity assessment (<0.05), and breaking bad news (0.001). Regarding specific components of informed consent, capacity assessment, and breaking bad news, significant improvement was shown in some areas, while we failed to improve knowledge in others. Through faculty-facilitated small group discussion, surgery interns were able to develop frameworks for ethical practice that paralleled established frameworks. Skills-based training in clinical ethics resulted in an increase in knowledge scores and self-reported confidence. Evaluation of 4 annual cohorts of surgery interns demonstrates

  1. MHD Models and Laboratory Experiments of Jets

    NASA Astrophysics Data System (ADS)

    Gardiner, T. A.; Frank, A.; Blackman, E. G.; Lebedev, S. V.; Chittenden, J. P.; Ampleford, D.; Bland, S. N.; Ciardi, A.; Sherlock, M.; Haines, M. G.

    Jet research has long relied upon a combination of analytical, observational and numerical studies to elucidate the complex phenomena involved. One element missing from these studies (which other physical sciences utilize) is the controlled experimental investigation of such systems. With the advent of high-power lasers and fast Z-pinch machines it is now possible to experimentally study similar systems in a laboratory setting. Such investigations can contribute in two useful ways. They can be used for comparison with numerical simulations as a means to validate simulation codes. More importantly, however, such investigations can also be used to complement other jet research, leading to fundamentally new knowledge. In the first part of this article, we analyze the evolution of magnetized wide-angle winds in a collapsing environment. We track the ambient and wind mass separately and describe a physical mechanism by which an ionized central wind can entrain the ambient gas giving rise to internal shells of molecular material on short time scales. The formation of internal shells in molecular outflows has been found to be an important ingredient in describing the observations of convex spurs in P-V diagrams (Hubble wedges in M-V diagrams). In the second part, we present astrophysically relevant experiments in which supersonic jets are created using a conical wire array Z-pinch. The conically convergent flow generates a standing shock around the axis which collimates the flow into a Mach ~ 30 jet. The jet formation process is closely related to the work of Cantó et al. (1988) for hydrodynamic jet collimation. The influence of radiative cooling on collimation and stability is studied by varying the wire material (Al, Fe, and W).

  2. The laboratory experience in introductory physics courses

    NASA Astrophysics Data System (ADS)

    Di Stefano, Maria C.

    1997-03-01

    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.

  3. Density Estimations in Laboratory Debris Flow Experiments

    NASA Astrophysics Data System (ADS)

    Queiroz de Oliveira, Gustavo; Kulisch, Helmut; Malcherek, Andreas; Fischer, Jan-Thomas; Pudasaini, Shiva P.

    2016-04-01

    Bulk density and its variation is an important physical quantity to estimate the solid-liquid fractions in two-phase debris flows. Here we present mass and flow depth measurements for experiments performed in a large-scale laboratory set up. Once the mixture is released and it moves down the inclined channel, measurements allow us to determine the bulk density evolution throughout the debris flow. Flow depths are determined by ultrasonic pulse reflection, and the mass is measured with a total normal force sensor. The data were obtained at 50 Hz. The initial two phase material was composed of 350 kg debris with water content of 40%. A very fine pebble with mean particle diameter of 3 mm, particle density of 2760 kg/m³ and bulk density of 1400 kg/m³ in dry condition was chosen as the solid material. Measurements reveal that the debris bulk density remains high from the head to the middle of the debris body whereas it drops substantially at the tail. This indicates lower water content at the tail, compared to the head and the middle portion of the debris body. This means that the solid and fluid fractions are varying strongly in a non-linear manner along the flow path, and from the head to the tail of the debris mass. Importantly, this spatial-temporal density variation plays a crucial role in determining the impact forces associated with the dynamics of the flow. Our setup allows for investigating different two phase material compositions, including large fluid fractions, with high resolutions. The considered experimental set up may enable us to transfer the observed phenomena to natural large-scale events. Furthermore, the measurement data allows evaluating results of numerical two-phase mass flow simulations. These experiments are parts of the project avaflow.org that intends to develop a GIS-based open source computational tool to describe wide spectrum of rapid geophysical mass flows, including avalanches and real two-phase debris flows down complex natural

  4. Laboratory modelling of an active space experiment using railgun as a launch device

    NASA Astrophysics Data System (ADS)

    Poniaev, S. A.; Kurakin, R. O.; Reznikov, B. I.; Rozov, S. I.; Zhukov, B. G.; Chernyshov, M. V.

    2017-06-01

    Laboratory modelling of active space experiments is described. To accelerate an impactor, a specially developed electromagnetic railgun capable of accelerating 10-mg cubic impactors to velocities of up to 5.5 km/s was used. As targets, different materials, such as ice and moon-like regolith, were employed. To simulate a collision with a comet, a hypervelocity impact on water ice targets with different densities was performed. To simulate an impact on the Moon's surface, a special method for preparation of regolith targets with the compositions corresponding to the Moon's surface materials was developed. The impact experiments with regoliths of different densities were carried out.

  5. Do-It-Yourself Experiments for the Instructional Laboratory

    ERIC Educational Resources Information Center

    Craig, Norman C.; Hill, Cortland S.

    2012-01-01

    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…

  6. Do-It-Yourself Experiments for the Instructional Laboratory

    ERIC Educational Resources Information Center

    Craig, Norman C.; Hill, Cortland S.

    2012-01-01

    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…

  7. Dielectron Production in Heavy Ions Collisions: the HADES Experiment

    SciTech Connect

    J. A. Garzon; H. Alvarez-Pol; I. Duran; C. Fernandez; B. Fuentes; R. Lorenzo; M. Sanchez; A. Vazquez-Cardesin

    1999-12-31

    HADES (High Acceptance Di-Electron Spectrometer) is being built at UNILAC-SIS in Darmstadt with the main purpose of studying the production of dilepton pairs in nucleus-nucleus collisions at energies of 1AGeV. The spectrometer is briefly described, and the responsibilities of the group from the University of Santiago de Compostela are discussed.

  8. Operational Amplifier Experiments for the Chemistry Laboratory.

    ERIC Educational Resources Information Center

    Braun, Robert D.

    1996-01-01

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

  9. Operational Amplifier Experiments for the Chemistry Laboratory.

    ERIC Educational Resources Information Center

    Braun, Robert D.

    1996-01-01

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

  10. Laboratory Experiments for Network Security Instruction

    ERIC Educational Resources Information Center

    Brustoloni, Jose Carlos

    2006-01-01

    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…

  11. Laboratory Experiments for Network Security Instruction

    ERIC Educational Resources Information Center

    Brustoloni, Jose Carlos

    2006-01-01

    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…

  12. Experience with a Hospital Laboratory Admission Screen

    PubMed Central

    Davey, P. W.; Letts, H. W.; Anderson, P. A.

    1970-01-01

    A comprehensive laboratory admission screen can be instituted in any large laboratory but only in one in command of conventional technology and with the co-operation of the laboratory, medical, nursing and admitting staff. The capital equipment required is costly and subject to early obsolescence. The operating costs are initially high, but the influence of the screen on the general work load indicates that the total overall procedures ordered by the physician will be reduced in number and that over a three-year period, in an economy subject to continuous inflationary pressure, the total cost will approach what might have been expected had the screen not been instituted. By presenting, shortly after admission, a truly comprehensive laboratory profile, the total number of procedures ordered will be reduced and this reduction bears no relationship to whether or not the data supplied are medically useful. The equipment more recently available for a large admission screen is far superior, from the point of view of speed of assay and cost of maintenance and production, to the equipment that has been available to us in this study. It is believed that the unit cost of assay will continue to decline and that the principle of unsolicited testing will be expanded in the future to include procedures not presently in the profile. It is predicted that in the relatively near future almost all of the laboratory procedures that a clinician could conceivably request will have been done prior to his examination of the patient. PMID:5430051

  13. Bioremediation process on Brazil shoreline. Laboratory experiments.

    PubMed

    Rosa, Anabela P; Triguis, Jorge A

    2007-11-01

    Bioremediation technique can be considered a promising alternative to clean oil spills using microbial processes to reduce the concentration and/or the toxicity of pollutants. To understand the importance of this work we must know that there is only little research performed to date using bioremediation techniques to clean oil spills in tropical countries. So, the main objective of this work is to analyze the behavior of a laboratory's bioremediation test using nutrients on coastal sediments. The bioremediation process is followed through geochemical analysis during the tests. This organic material is analyzed by medium pressure liquid chromatography (MPLC), gas chromatography/flame ionization detection (GC/FID) and gas chromatography/ mass spectrometry. By microbial counting, the number of total bacteria and degrading bacteria is determined during the experiments, in order to confirm the effectiveness of the bioremediation process. The seawater obtained throughout the bioremediation process is analyzed for nutrients grade (phosphate and ammonium ions) and also for its toxicity (Microtox tests) due the presence of hydrocarbons and fertilizer. The results from the geochemical analyses of the oil show a relative decrease in the saturated hydrocarbon fraction that is compensated by a relative enrichment on polar compounds. It's confirmed by the fingerprint evaluation where it is possible to see a complete reduction of the normal alkanes followed by isoprenoids. Seawater analysis done by toxicity and nutrients analysis, such as microbial counting (total and degrading bacteria), confirm the fertilizer effectiveness during the bioremediation process. Results from simulating test using NPK, a low-price plant fertilizer, suggest that it's able to stimulate the degradation process. Results from medium pressure liquid chromatography (MPLC), done at two different depths (surface and subsurface), show different behavior during the biodegradation process where the later is seen

  14. The Unstructured Student-Designed Research Type of Laboratory Experiment.

    ERIC Educational Resources Information Center

    Macias-Machin, Agustin; And Others

    1990-01-01

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

  15. The Unstructured Student-Designed Research Type of Laboratory Experiment.

    ERIC Educational Resources Information Center

    Macias-Machin, Agustin; And Others

    1990-01-01

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

  16. Practical Enzyme Kinetics: A Biochemical Laboratory Experiment.

    ERIC Educational Resources Information Center

    Rowe, H. Alan; Brown, Morris

    1988-01-01

    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)

  17. Brownian Motion--a Laboratory Experiment.

    ERIC Educational Resources Information Center

    Kruglak, Haym

    1988-01-01

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

  18. Catching Collisions in the LHC

    SciTech Connect

    Fruguiele, Claudia; Hirschauer, Jim

    2015-06-16

    Now that the Large Hadron Collider has officially turned back on for its second run, within every proton collision could emerge the next new discovery in particle physics. Learn how the detectors on the Compact Muon Solenoid, or CMS, experiment capture and track particles as they are expelled from a collision. Talking us through these collisions are Claudia Fruguiele and Jim Hirschauer of Fermi National Accelerator Laboratory, the largest U.S. institution collaborating on the LHC.

  19. Catching Collisions in the LHC

    ScienceCinema

    Fruguiele, Claudia; Hirschauer, Jim

    2016-07-12

    Now that the Large Hadron Collider has officially turned back on for its second run, within every proton collision could emerge the next new discovery in particle physics. Learn how the detectors on the Compact Muon Solenoid, or CMS, experiment capture and track particles as they are expelled from a collision. Talking us through these collisions are Claudia Fruguiele and Jim Hirschauer of Fermi National Accelerator Laboratory, the largest U.S. institution collaborating on the LHC.

  20. Principles of Radio: A Laboratory Experiment

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2002-01-01

    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"…

  1. Principles of Radio: A Laboratory Experiment

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2002-01-01

    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"…

  2. Laboratory Experiment on Electrokinetic Remediation of Soil

    ERIC Educational Resources Information Center

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

    2011-01-01

    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…

  3. Laboratory Experiences in Marine Biology, Student Edition.

    ERIC Educational Resources Information Center

    Raimist, Roger J.

    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…

  4. A Meaningful Experience in Laboratory Investigation

    ERIC Educational Resources Information Center

    Szinai, S. S.; Szinai, N.

    1976-01-01

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

  5. Laboratory Experiment on Electrokinetic Remediation of Soil

    ERIC Educational Resources Information Center

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

    2011-01-01

    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…

  6. Colorimetric Titration Experiment for the Undergraduate Laboratory.

    ERIC Educational Resources Information Center

    Lopez, Edwin; Vassos, Basil H.

    1984-01-01

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

  7. Work Experience of Certified Laboratory Assistants.

    ERIC Educational Resources Information Center

    National Council on Medical Technology Education, Bethesda, MD.

    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…

  8. A Laboratory Experiment on the Statistical Theory of Nuclear Reactions

    ERIC Educational Resources Information Center

    Loveland, Walter

    1971-01-01

    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…

  9. Description of the Spacecraft Control Laboratory Experiment (SCOLE) facility

    NASA Technical Reports Server (NTRS)

    Williams, Jeffrey P.; Rallo, Rosemary A.

    1987-01-01

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

  10. Description of the Spacecraft Control Laboratory Experiment (SCOLE) facility

    NASA Technical Reports Server (NTRS)

    Williams, Jeffrey P.; Rallo, Rosemary A.

    1987-01-01

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

  11. Industrial Hygiene Laboratory accreditation: The JSC experience

    NASA Technical Reports Server (NTRS)

    Fadner, Dawn E.

    1993-01-01

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

  12. Production of defects in metals by collision cascades: TEM experiments

    SciTech Connect

    Kirk, M.A.

    1996-01-01

    This paper reviews experimental TEM data on production of dislocation loops by low energy ion bombardment to low doses, as simulations of similar collision cascades produced by fast neutrons, in various metals and alloys. Dependence of vacancy dislocation loop formation on recoil energy, temperature and metal/alloy is examined. Emphasis is placed on effects on dilute alloy additions. A model for cascade melting is used to understand these effects; this will require an examination of the role of electron-phonon coupling in cascade cooling and recrystallization. Formation of interstitial dislocation loops as cascade defects and the effect of nearby surfaces are briefly discussed.

  13. Will Allis Prize Talk: Electron Collisions - Experiment, Theory and Applications

    NASA Astrophysics Data System (ADS)

    Bartschat, Klaus

    2016-05-01

    Electron collisions with atoms, ions, and molecules represent one of the very early topics of quantum mechanics. In spite of the field's maturity, a number of recent developments in detector technology (e.g., the ``reaction microscope'' or the ``magnetic-angle changer'') and the rapid increase in computational resources have resulted in significant progress in the measurement, understanding, and theoretical/computational description of few-body Coulomb problems. Close collaborations between experimentalists and theorists worldwide continue to produce high-quality benchmark data, which allow for thoroughly testing and further developing a variety of theoretical approaches. As a result, it has now become possible to reliably calculate the vast amount of atomic data needed for detailed modelling of the physics and chemistry of planetary atmospheres, the interpretation of astrophysical data, optimizing the energy transport in reactive plasmas, and many other topics - including light-driven processes, in which electrons are produced by continuous or short-pulse ultra-intense electromagnetic radiation. In this talk, I will highlight some of the recent developments that have had a major impact on the field. This will be followed by showcasing examples, in which accurate electron collision data enabled applications in fields beyond traditional AMO physics. Finally, open problems and challenges for the future will be outlined. I am very grateful for fruitful scientific collaborations with many colleagues, and the long-term financial support by the NSF through the Theoretical AMO and Computational Physics programs, as well as supercomputer resources through TeraGrid and XSEDE.

  14. Buffer Capacity: An Undergraduate Laboratory Experiment.

    ERIC Educational Resources Information Center

    Russo, Steven O.; Hanania, George I. H.

    1987-01-01

    Describes a quantitative experiment designed to demonstrate buffer action and the measurement of buffer capacity. Discusses how to make acetate buffers, determine their buffer capacity, plot the capacity/pH curve, and interpret the data obtained. (TW)

  15. Recycle with Heating: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Foord, A.; Mason, G.

    1985-01-01

    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)

  16. Recycle with Heating: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Foord, A.; Mason, G.

    1985-01-01

    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)

  17. Buffer Capacity: An Undergraduate Laboratory Experiment.

    ERIC Educational Resources Information Center

    Russo, Steven O.; Hanania, George I. H.

    1987-01-01

    Describes a quantitative experiment designed to demonstrate buffer action and the measurement of buffer capacity. Discusses how to make acetate buffers, determine their buffer capacity, plot the capacity/pH curve, and interpret the data obtained. (TW)

  18. Plasma kinetic effects on interfacial mix in settings relevant to inertial confinement fusion and laboratory experiments

    NASA Astrophysics Data System (ADS)

    Yin, L.; Albright, B. J.; Bergen, B.; Bowers, K. J.; Vold, E. L.; Molvig, K.; Fernández, J. C.; Bang, W.; Bradley, P. A.; Gautier, D. C.; Hamilton, C. E.; Palaniyappan, S.; Santiago Cordoba, M. A.; Hegelich, B. M.; Dyer, G.; Roycroft, R.

    2015-11-01

    Mixing of high-Z/low-Z interfaces in dense plasma media is a problem of importance for understanding mix in inertial confinement fusion experiments and recent experiments at the LANL Trident facility. In this presentation, we apply the VPIC particle-in-cell code with a binary collision model to explore kinetic effects of the atomic mixing. Comparisons are made to published analytic theory and hybrid modeling results and conditions are identified under which plasma kinetic behavior may lead to anomalously rapid atomic mixing. Work performed under the auspices of the U.S. DOE by the LANS, LLC, Los Alamos National Laboratory under Contract No. DE-AC52-06NA25396. Funding provided by the Los Alamos National Laboratory Directed Research and Development Program.

  19. The Himalaya-Tibet System: A Natural laboratory for continental collision and seismogenesis

    NASA Astrophysics Data System (ADS)

    Meltzer, A.; Brown, L. D.; Song, X.

    2015-12-01

    The Himalaya-Tibet system remains one of the best places to study continental dynamics, mountain building, and nucleation of great earthquakes. Over the past several decades, numerous research projects have used the Himalaya and Tibet as a natural laboratory to investigate the process of continental collision. Much has been learned about the orogen, including the remarkable along-strike continuity of many features: the orogen's basic geology and structure, the morphology and drainages of the Himalayan arc, and the apparent symmetry of the syntaxes at either end. At the same time, numerous focused studies have also identified considerable spatial variability in the GPS field, seismicity, crust and mantle structure, magnitude and timing of exhumation, erosion, and strain. While much has been learned and many details revealed, significant questions about the Himalaya and Tibet remain and we lack integrated 4D models that explain observed complexity. The time is right for a community initiative to systematically integrate the breadth of data available to test and refine geodynamic models to illuminate the structure and 4-D evolution of the India-Asia collision at scales that account for both first order observations and lateral heterogeneity, link deep earth and surface processes, and address the geohazards associated with the collisional zone and surrounding areas. Any such effort requires community consensus on science goals, setting priorities regarding what's needed to make significant progress, and open access data. An effort of this scale needs to address the societal impacts of hazards associated with the India-Asia collisional system and engage international collaborations across the region. The April 2015 Mw 7.8 Gorkha, Nepal earthquake serves as the most recent reminder that the Himalaya-Tibet system is capable of producing large magnitude events, impacting lives, livelihoods, and the built environment. The 1950 Mw 8.6 Assam and 2008 Mw 7.9 Wenchuan

  20. Improving Target Characterization for Laboratory Astrophysics Experiments

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

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

  1. The generation and amplification of intergalactic magnetic fields in analogue laboratory experiments with high power lasers

    NASA Astrophysics Data System (ADS)

    Gregori, G.; Reville, B.; Miniati, F.

    2015-11-01

    The advent of high-power laser facilities has, in the past two decades, opened a new field of research where astrophysical environments can be scaled down to laboratory dimensions, while preserving the essential physics. This is due to the invariance of the equations of magneto-hydrodynamics to a class of similarity transformations. Here we review the relevant scaling relations and their application in laboratory astrophysics experiments with a focus on the generation and amplification of magnetic fields in cosmic environment. The standard model for the origin of magnetic fields is a multi stage process whereby a vanishing magnetic seed is first generated by a rotational electric field and is then amplified by turbulent dynamo action to the characteristic values observed in astronomical bodies. We thus discuss the relevant seed generation mechanisms in cosmic environment including resistive mechanism, collision-less and fluid instabilities, as well as novel laboratory experiments using high power laser systems aimed at investigating the amplification of magnetic energy by magneto-hydrodynamic (MHD) turbulence. Future directions, including efforts to model in the laboratory the process of diffusive shock acceleration are also discussed, with an emphasis on the potential of laboratory experiments to further our understanding of plasma physics on cosmic scales.

  2. Laboratory experiments in integrated circuit fabrication

    NASA Technical Reports Server (NTRS)

    Jenkins, Thomas J.; Kolesar, Edward S.

    1993-01-01

    The objectives of the experiment are fourfold: to provide practical experience implementing the fundamental processes and technology associated with the science and art of integrated circuit (IC) fabrication; to afford the opportunity for the student to apply the theory associated with IC fabrication and semiconductor device operation; to motivate the student to exercise engineering decisions associated with fabricating integrated circuits; and to complement the theory of n-channel MOS and diffused devices that are presented in the classroom by actually fabricating and testing them. Therefore, a balance between theory and practice can be realized in the education of young engineers, whose education is often criticized as lacking sufficient design and practical content.

  3. [Experience with laboratory diagnosis of Clostridium difficile].

    PubMed

    Bareková, L; Zálabská, E; Hanovcová, I

    2013-09-01

    Clostridium difficile is currently a significant cause of nosocomial diarrhea. For several years, the number of infectious cases in the community has also been increasing. Since the beginning of 2010, quite a large increase in the number of Clostridium difficile infections (CDIs) has been noted in Pardubice Regional Hospital (PRH). The objectives of this study were to describe and evaluate the methods used in the laboratory diagnosis of CDIs in PRH, and to describe the laboratory diagnostic algorithm used here. Samples of stools were taken from symptomatic patients hospitalized or examined in the outpatient departments of PRH from 1 July 2010 to 31 December 2012. For the detection of glutamate dehydrogenase (GDH) and toxin A/B, the dual test based upon the principle enzyme immunoassays C. Diff Quik Chek Complete, Techlabo (D-EIA) was used. The system GeneXpert PCR Cepheid (PCR) was used for confirmation of laboratory findings. Since the beginning of 2011, all the GDH-positive samples were cultured. A total of 2,040 samples were examined. The D-EIA test was used for examination of 2,014 samples. Of those, 1,373 (68.2 %) samples were GDH- and toxin A/B-negative. In 359 (17.8 %) samples, both GDH and toxin A/B were detected. The D-EIA sensitivity and specificity for detecting toxigenic strains in stool samples were 21.8% and 97.2%, respectively. The PPV and NPV rates calculated for the populations with prevalence rates of disorders of 5%, 10%, 20% and 50 % were 0.29, 0.46, 0.66, 0.88 and 0.96, 0.92, 0.83, 0.55, respectively. The sensitivity and specificity of GDH for the detection of Clostridium difficile in stools were 100.0% and 96.2%, respectively. PCR examination was carried out in 140 samples. Of those, 82 samples were PCR-positive. The gene for the production of toxin B was detected in 47%, the finding suspected for ribotype 027 (gene for toxin B, binary toxin and deletion of tcdC) in 48%. In 5% of the samples, the gene for toxin B and the gene for the binary

  4. Simple Laboratory Experiment for Illustrating Soil Respiration.

    ERIC Educational Resources Information Center

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

    1997-01-01

    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…

  5. Laboratory plate tectonics: a new experiment.

    PubMed

    Gans, R F

    1976-03-26

    A "continent" made of a layer of hexagonally packed black polyethylene spheres floating in clear silicon oil breaks into subcontinents when illuminated by an ordinary incandescent light bulb. This experiment may be a useful model of plate tectonics driven by horizontal temperature gradients. Measurements of the spreading rate are made to establish the feasibility of this model.

  6. Simple Laboratory Experiment for Illustrating Soil Respiration.

    ERIC Educational Resources Information Center

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

    1997-01-01

    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…

  7. Experiences of model year 2011 Dodge and Jeep owners with collision avoidance and related technologies.

    PubMed

    Cicchino, Jessica B; McCartt, Anne T

    2015-01-01

    Crash avoidance technologies have the potential to prevent or mitigate many crashes, but their effectiveness depends on drivers' acceptance and proper use. Owners of 2011 Dodge Charger, Dodge Durango, and Jeep Grand Cherokee vehicles were interviewed about their experiences with their vehicles' technologies. Interviews were conducted in April 2013 with 215 owners of Dodge and Jeep vehicles with adaptive cruise control and forward collision warning and 215 owners with blind spot monitoring and rear cross-path detection. Most owners said that they always keep each collision avoidance technology turned on, and more than 90% of owners with each system would want the technology again on their next vehicle. The majority believed that the systems had helped prevent a collision; this ranged from 54% of drivers with forward collision warning to more than three-quarters with blind spot monitoring and rear cross-path detection. Some owners reported behavioral changes with the systems, but over-reliance on them is not prevalent. Reported use of the systems varied by the age and gender of the driver and duration of vehicle ownership to a greater degree than in previous surveys of luxury Volvo and Infiniti vehicles with collision avoidance technologies. Notably, drivers aged 40 and younger were most likely to report that forward collision warning had alerted them multiple times and that it had prevented a collision and that they follow the vehicle ahead less closely with adaptive cruise control. Reports of waiting for the alert from forward collision warning before braking were infrequent but increased with duration of ownership. However, these reports could reflect confusion of the system with adaptive cruise control, which alerts drivers when braking is necessary to maintain a preset speed or following distance but a crash is not imminent. Consistent with previous surveys of luxury vehicle owners with collision avoidance technologies, acceptance and use remains high among

  8. Millikan's oil-drop experiment as a remotely controlled laboratory

    NASA Astrophysics Data System (ADS)

    Eckert, Bodo; Gröber, Sebastian; Vetter, Martin; Jodl, Hans-Jörg

    2012-09-01

    The Millikan oil-drop experiment, to determine the elementary electrical charge e and the quantization of charge Q = n · 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 of the experiment and the quality of measurements. The added value to offer the Millikan experiment as an RCL is pointed out.

  9. Symmetron dark energy in laboratory experiments.

    PubMed

    Upadhye, Amol

    2013-01-18

    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 μ~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 λ is < or approximately equal to 7.5.

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

    ERIC Educational Resources Information Center

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

    2012-01-01

    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…

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

    ERIC Educational Resources Information Center

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

    2012-01-01

    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…

  12. A Simple Photochemical Experiment for the Advanced Laboratory.

    ERIC Educational Resources Information Center

    Rosenfeld, Stuart M.

    1986-01-01

    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,…

  13. A Simple Photochemical Experiment for the Advanced Laboratory.

    ERIC Educational Resources Information Center

    Rosenfeld, Stuart M.

    1986-01-01

    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,…

  14. Laboratory modeling of ionospheric heating experiments

    NASA Astrophysics Data System (ADS)

    Starodubtsev, M. V.; Nazarov, V. V.; Gushchin, M. E.; Kostrov, A. V.

    2016-10-01

    Turbulent plasma processes, such as those which occur in the Earth's ionosphere during ionospheric heating by powerful radio waves, were studied under laboratory conditions, and new physical models of small-scale ionospheric turbulence are proposed as a result of these studies. It is shown here that the mechanism of small-scale plasma filamentation can be connected with the thermal self-channeling of Langmuir waves. During this process, Langmuir waves are guided by a plasma channel, which in turn is formed by the guided waves through a thermal plasma nonlinearity. The spectrum of the self-guided Langmuir waves exhibits sidebands whose features are similar to stimulated electromagnetic emission. We present two mechanisms of sideband generation. The first mechanism can be observed during the formation of the plasma channel and is connected with the parametric shift in the frequency of the self-channeling wave. The second mechanism is connected with the scattering of the self-channeling wave on the low-frequency eigenmodes of the plasma irregularity.

  15. Agreed Discoveries: Students' Negotiations in a Virtual Laboratory Experiment

    ERIC Educational Resources Information Center

    Karlsson, Goran; Ivarsson, Jonas; Lindstrom, Berner

    2013-01-01

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

  16. Agreed Discoveries: Students' Negotiations in a Virtual Laboratory Experiment

    ERIC Educational Resources Information Center

    Karlsson, Goran; Ivarsson, Jonas; Lindstrom, Berner

    2013-01-01

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

  17. Some Experiments with Biological Applications for the Elementary Laboratory

    ERIC Educational Resources Information Center

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

    1975-01-01

    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)

  18. Laboratory Experiments on the Electrochemical Remediation of the Environment

    ERIC Educational Resources Information Center

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

    2004-01-01

    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.

  19. Laboratory Experiments on the Electrochemical Remediation of the Environment

    ERIC Educational Resources Information Center

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

    2004-01-01

    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.

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

    ERIC Educational Resources Information Center

    Ewing, Sheila

    1982-01-01

    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)

  1. Pilot Experience of Teaching a History of Physics Laboratory

    ERIC Educational Resources Information Center

    Hoddeson, Lillian Hartmann

    1971-01-01

    Outlines laboratory activities designed to permit both majors and non-majors to perform crucial experiments in physics, using, when possible, replicas of original apparatus and copies of translations of original texts. (PR)

  2. High Performance Liquid Chromatography Experiments to Undergraduate Laboratories

    ERIC Educational Resources Information Center

    Kissinger, Peter T.; And Others

    1977-01-01

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

  3. Pilot Experience of Teaching a History of Physics Laboratory

    ERIC Educational Resources Information Center

    Hoddeson, Lillian Hartmann

    1971-01-01

    Outlines laboratory activities designed to permit both majors and non-majors to perform crucial experiments in physics, using, when possible, replicas of original apparatus and copies of translations of original texts. (PR)

  4. Progress in Laboratory Gravitational Experiments in Hust Group

    NASA Astrophysics Data System (ADS)

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

    2013-09-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Davis, M. H.

    1977-01-01

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

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

    ERIC Educational Resources Information Center

    Ewing, Sheila

    1982-01-01

    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)

  7. High Performance Liquid Chromatography Experiments to Undergraduate Laboratories

    ERIC Educational Resources Information Center

    Kissinger, Peter T.; And Others

    1977-01-01

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

  8. Some Experiments with Biological Applications for the Elementary Laboratory

    ERIC Educational Resources Information Center

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

    1975-01-01

    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)

  9. Laser Speckle Photography: Some Simple Experiments for the Undergraduate Laboratory.

    ERIC Educational Resources Information Center

    Bates, B.; And Others

    1986-01-01

    Describes simple speckle photography experiments which are easy to set up and require only low cost standard laboratory equipment. Included are procedures for taking single, double, and multiple exposures. (JN)

  10. The Binary Collision-Induced Second Overtone Band of Gaseous Hydrogen: Modelling and Laboratory Measurements

    NASA Technical Reports Server (NTRS)

    Brodbeck, C.; Bouanich, J.-P.; Nguyen, Van Thanh; Borysow, Aleksandra

    1999-01-01

    Collision-induced absorption (CIA) is the major source of the infrared opacity of dense planetary atmospheres which are composed of nonpolar molecules. Knowledge of CIA absorption spectra of H2-H2 pairs is important for modelling the atmospheres of planets and cold stars that are mainly composed of hydrogen. The spectra of hydrogen in the region of the second overtone at 0.8 microns have been recorded at temperatures of 298 and 77.5 K for gas densities ranging from 100 to 800 amagats. By extrapolation to zero density of the absorption coefficient measured every 10 cm(exp -1) in the spectral range from 11100 to 13800 cm(exp -1), we have determined the binary absorption coefficient. These extrapolated measurements are compared with calculations based on a model that was obtained by using simple computer codes and lineshape profiles. In view of the very weak absorption of the second overtone band, we find the agreement between results of the model and experiment to be reasonable.

  11. First experiments probing the collision of parallel magnetic fields using laser-produced plasmas

    DOE PAGES

    Rosenberg, M. J.; Li, C. K.; Fox, W.; ...

    2015-04-08

    Novel experiments to study the strongly-driven collision of parallel magnetic fields in β~10, laser-produced plasmas have been conducted using monoenergetic proton radiography. These experiments were designed to probe the process of magnetic flux pileup, which has been identified in prior laser-plasma experiments as a key physical mechanism in the reconnection of anti-parallel magnetic fields when the reconnection inflow is dominated by strong plasma flows. In the present experiments using colliding plasmas carrying parallel magnetic fields, the magnetic flux is found to be conserved and slightly compressed in the collision region. Two-dimensional (2D) particle-in-cell (PIC) simulations predict a stronger flux compressionmore » and amplification of the magnetic field strength, and this discrepancy is attributed to the three-dimensional (3D) collision geometry. Future experiments may drive a stronger collision and further explore flux pileup in the context of the strongly-driven interaction of magnetic fields.« less

  12. Location for the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This diagram shows the planned locations of the Space Experiment Research and Processing Laboratory (SERPL) and the Space Station Commerce Park at Kennedy Space Center. The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for the planned 400- acre commerce park.

  13. Location for the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This diagram shows the planned locations of the Space Experiment Research and Processing Laboratory (SERPL) and the Space Station Commerce Park at Kennedy Space Center. The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for the planned 400- acre commerce park.

  14. Establishing laboratory standards for biological flight experiments

    NASA Technical Reports Server (NTRS)

    Young, Ronald B.; Moriarity, Debra M.

    1989-01-01

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

  15. Laboratory Noble Gas Migration Experiments through Rock

    NASA Astrophysics Data System (ADS)

    Broome, S.; Cashion, A.; Feldman, J.; Sussman, A. J.; Swanson, E.; Wilson, J.

    2016-12-01

    The Underground Nuclear Explosion Signatures Experiment (UNESE) was created to address science and research and development aspects associated with nuclear explosion verification and nuclear nonproliferation with a focus on non-prompt signals. A critical component of the UNESE program is a realistic understanding of the post-detonation processes and changes in the environment that produce observable physical and radio-chemical signatures. As such, an understanding of noble gas migration properties through various lithologies is essential. Here we present an empirical methodology to measure tortuosity on well-characterized rhyolitic tuffs and lavas. Tortuosity is then compared with microfracture networks characterized by microscopy. To quantify tortuosity, a pressurized (1500 mbar) fixed volume of argon is expanded into a sample under high vacuum (0.200 mbar). A quadrupole mass spectrometer (QMS) is used to measure argon downstream of the sample in real time, allowing the time-series gas arrival curve to be characterized for each sample. To evaluate the method, blank samples have been machined to correspond with tortuosities of 1, 2, and 4 in conjunction with a restricted-flow valve to mimic rock sample permeability. Data from the blanks are analyzed with this system to correct for system effects on gas arrival. High vacuum is maintained in the QMS system during sampling by precise metering of the gas through a leak valve with active feedback control which allows arrival time and concentration of argon to be established in real time. Along with a comprehensive characterization of the rock and fracture properties, the parameters derived from these experiments will provide invaluable insight into the three-dimensional structure of damage zones, the production of temporally variable signatures and the methods to best detect underground nuclear explosion signatures. SAND2016-7309 A

  16. The suborbital particle aggregation and collision experiment (SPACE): Studying the collision behavior of submillimeter-sized dust aggregates on the suborbital rocket flight REXUS 12

    NASA Astrophysics Data System (ADS)

    Brisset, Julie; Heißelmann, Daniel; Kothe, Stefan; Weidling, René; Blum, Jürgen

    2013-09-01

    The Suborbital Particle Aggregation and Collision Experiment (SPACE) is a novel approach to study the collision properties of submillimeter-sized, highly porous dust aggregates. The experiment was designed, built, and carried out to increase our knowledge about the processes dominating the first phase of planet formation. During this phase, the growth of planetary precursors occurs by agglomeration of micrometer-sized dust grains into aggregates of at least millimeters to centimeters in size. However, the formation of larger bodies from the so-formed building blocks is not yet fully understood. Recent numerical models on dust growth lack a particular support by experimental studies in the size range of submillimeters, because these particles are predicted to collide at very gentle relative velocities of below 1 cm/s that can only be achieved in a reduced-gravity environment. The SPACE experiment investigates the collision behavior of an ensemble of silicate-dust aggregates inside several evacuated glass containers which are being agitated by a shaker to induce the desired collisions at chosen velocities. The dust aggregates are being observed by a high-speed camera, allowing for the determination of the collision properties of the protoplanetary dust analog material. The data obtained from the suborbital flight with the REXUS (Rocket Experiments for University Students) 12 rocket will be directly implemented into a state-of-the-art dust growth and collision model.

  17. The Suborbital Particle Aggregation and Collision Experiment (SPACE): studying the collision behavior of submillimeter-sized dust aggregates on the suborbital rocket flight REXUS 12.

    PubMed

    Brisset, Julie; Heißelmann, Daniel; Kothe, Stefan; Weidling, René; Blum, Jürgen

    2013-09-01

    The Suborbital Particle Aggregation and Collision Experiment (SPACE) is a novel approach to study the collision properties of submillimeter-sized, highly porous dust aggregates. The experiment was designed, built, and carried out to increase our knowledge about the processes dominating the first phase of planet formation. During this phase, the growth of planetary precursors occurs by agglomeration of micrometer-sized dust grains into aggregates of at least millimeters to centimeters in size. However, the formation of larger bodies from the so-formed building blocks is not yet fully understood. Recent numerical models on dust growth lack a particular support by experimental studies in the size range of submillimeters, because these particles are predicted to collide at very gentle relative velocities of below 1 cm/s that can only be achieved in a reduced-gravity environment. The SPACE experiment investigates the collision behavior of an ensemble of silicate-dust aggregates inside several evacuated glass containers which are being agitated by a shaker to induce the desired collisions at chosen velocities. The dust aggregates are being observed by a high-speed camera, allowing for the determination of the collision properties of the protoplanetary dust analog material. The data obtained from the suborbital flight with the REXUS (Rocket Experiments for University Students) 12 rocket will be directly implemented into a state-of-the-art dust growth and collision model.

  18. Electron transport and energy degradation in the ionosphere: Evaluation of the numerical solution, comparison with laboratory experiments and auroral observations

    NASA Technical Reports Server (NTRS)

    Lummerzheim, D.; Lilensten, J.

    1994-01-01

    Auroral electron transport calculations are a critical part of auroral models. We evaluate a numerical solution to the transport and energy degradation problem. The numerical solution is verified by reproducing simplified problems to which analytic solutions exist, internal self-consistency tests, comparison with laboratory experiments of electron beams penetrating a collision chamber, and by comparison with auroral observations, particularly the emission ratio of the N2 second positive to N2(+) first negative emissions. Our numerical solutions agree with range measurements in collision chambers. The calculated N(2)2P to N2(+)1N emission ratio is independent of the spectral characteristics of the incident electrons, and agrees with the value observed in aurora. Using different sets of energy loss cross sections and different functions to describe the energy distribution of secondary electrons that emerge from ionization collisions, we discuss the uncertainties of the solutions to the electron transport equation resulting from the uncertainties of these input parameters.

  19. Electron transport and energy degradation in the ionosphere: Evaluation of the numerical solution, comparison with laboratory experiments and auroral observations

    NASA Technical Reports Server (NTRS)

    Lummerzheim, D.; Lilensten, J.

    1994-01-01

    Auroral electron transport calculations are a critical part of auroral models. We evaluate a numerical solution to the transport and energy degradation problem. The numerical solution is verified by reproducing simplified problems to which analytic solutions exist, internal self-consistency tests, comparison with laboratory experiments of electron beams penetrating a collision chamber, and by comparison with auroral observations, particularly the emission ratio of the N2 second positive to N2(+) first negative emissions. Our numerical solutions agree with range measurements in collision chambers. The calculated N(2)2P to N2(+)1N emission ratio is independent of the spectral characteristics of the incident electrons, and agrees with the value observed in aurora. Using different sets of energy loss cross sections and different functions to describe the energy distribution of secondary electrons that emerge from ionization collisions, we discuss the uncertainties of the solutions to the electron transport equation resulting from the uncertainties of these input parameters.

  20. ISO 15189 accreditation: Requirements for quality and competence of medical laboratories, experience of a laboratory I.

    PubMed

    Guzel, Omer; Guner, Ebru Ilhan

    2009-03-01

    Medical laboratories are the key partners in patient safety. Laboratory results influence 70% of medical diagnoses. Quality of laboratory service is the major factor which directly affects the quality of health care. The clinical laboratory as a whole has to provide the best patient care promoting excellence. International Standard ISO 15189, based upon ISO 17025 and ISO 9001 standards, provides requirements for competence and quality of medical laboratories. Accredited medical laboratories enhance credibility and competency of their testing services. Our group of laboratories, one of the leading institutions in the area, had previous experience with ISO 9001 and ISO 17025 Accreditation at non-medical sections. We started to prepared for ISO 15189 Accreditation at the beginning of 2006 and were certified in March, 2007. We spent more than a year to prepare for accreditation. Accreditation scopes of our laboratory were as follows: clinical chemistry, hematology, immunology, allergology, microbiology, parasitology, molecular biology of infection serology and transfusion medicine. The total number of accredited tests is 531. We participate in five different PT programs. Inter Laboratory Comparison (ILC) protocols are performed with reputable laboratories. 82 different PT Program modules, 277 cycles per year for 451 tests and 72 ILC program organizations for remaining tests have been performed. Our laboratory also organizes a PT program for flow cytometry. 22 laboratories participate in this program, 2 cycles per year. Our laboratory has had its own custom made WEB based LIS system since 2001. We serve more than 500 customers on a real time basis. Our quality management system is also documented and processed electronically, Document Management System (DMS), via our intranet. Preparatory phase for accreditation, data management, external quality control programs, personnel related issues before, during and after accreditation process are presented. Every laboratory has

  1. Upgrades for the STAR Experiment Slow Controls at Brookhaven National Laboratory

    NASA Astrophysics Data System (ADS)

    Ruiz, Samuel; Fujita, Jiro

    2016-09-01

    The STAR (Solenoidal Tracker at RHIC) experiment at Brookhaven National Laboratory studies the collisions of relativistic heavy ions. Some components of the control system for STAR have not changed since STAR became operational in 2000. The goal of this project is to upgrade the control system software for easier maintenance. The software upgrade also requires modernizing the hardware in some cases. A prototype for monitoring the Field Cage for the Time Projection Chamber (TPC) and a prototype for controlling the TPC front-end electronics using a programmable logic controller were developed. Newly developed software for the hygrometer to monitor the experiment environment was deployed at the experiment. Details about the software and hardware upgrades, as well as the developed prototypes will be presented.

  2. Impact cratering in viscous targets - Laboratory experiments

    NASA Technical Reports Server (NTRS)

    Greeley, R.; Fink, J.; Snyder, D. B.; Gault, D. E.; Guest, J. E.; Schultz, P. H.

    1980-01-01

    To determine the effects of target yield strength and viscosity on the formation and morphology of Martian multilobed, slosh and rampart-type impact craters, 75 experiments in which target properties and impact energies were varied were carried out for high-speed motion picture observation in keeping with the following sequence: (1) projectile initial impact; (2) crater excavation and rise of ejecta plume; (3) formation of a transient central mound which generates a surge of material upon collapse that can partly override the plume deposit; and (4) oscillation of the central mound with progressively smaller surges of material leaving the crater. A dimensional analysis of the experimental results indicates that the dimensions of the central mound are proportional to (1) the energy of the impacting projectile and (2) to the inverse of both the yield strength and viscosity of the target material, and it is determined that extrapolation of these results to large Martian craters requires an effective surface layer viscosity of less than 10 to the 10th poise. These results may also be applicable to impacts on outer planet satellites composed of ice-silicate mixtures.

  3. The JPL MSAT mobile laboratory and the pilot field experiments

    NASA Technical Reports Server (NTRS)

    Berner, Jeff B.; Emerson, Richard F.

    1988-01-01

    A Mobile Laboratory/Propagation Measurement Van (PMV) was developed to support the field experiments of the Mobile Satellite Experiment (MSAT-X) Project. This van was designed to provide flexibility, self-sufficiency and data acquisition to allow for both measurement of equipment performance and the mobile environment. The design philosophy and implementation of the PMV are described. The Pilot Field Experiments and an overall description of the three experiments in which the PMV was used are described.

  4. Carbonatisation of Weathered Peridotites in Laboratory Experiments

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    Enhanced in-situ carbonatisation of ultramafic rocks has been proposed as a strategy for a permanent and safe storage of CO2 in order to reduce anthropogenic greenhouse gas emissions (e.g., Kelemen and Matter 2008). This idea emerged from studies of natural examples demonstrating that ultramafic rocks react extensively with CO2 to form ophicarbonates. However, despite their Mg-rich nature, ultramafic rocks are often associated with calcite (CaCO3) rather than magnesite (MgCO3) and dolomite (CaMg(CO3)2). Whether these so-called ophicalcites represent sedimentary or tectonic breccias or are produced during hydrothermal alteration of ultramafic rocks, has been discussed for many years (e.g., Folk and McBride 1976). The view that reactions between hydrothermal fluids and ultramafic rocks can result in the formation of ophicalcite was recently supported by Beinlich et al. (2010), who documented Ca- and CO2-metasomatism and extreme Mg depletion in serpentinised and weathered peridotite clasts from the conglomerates of the Solund basin (SW Norway). This study also suggests that weathering is an important factor for the carbonatisation of ultramafic rocks. We have performed hydrothermal experiments on weathered peridotites in order to better constrain the mechanisms and conditions that trigger Mg-loss from ultramafic rocks and subsequent calcite precipitation. Un-crushed, partly serpentinised and weathered peridotite samples were allowed to react in a Ca-bearing saline solution under CO2 pressure (PCO2: 130-160 bar) at 200°C. We were able to illustrate the textural and chemical evolution during the reaction through a detailed comparison of the solid and fluid samples before and after the experiments. The initial samples showed a typical mesh texture with veins of serpentine surrounding meshes filled either with fresh or weathered olivine. The experimentally treated samples reveal a strongly reacted rim, predominantly composed of calcite, but still showing ghosts of the

  5. Results from Cu+Au collisions at 200 GeV in PHENIX Experiment

    SciTech Connect

    Berdnikov, Ya. A.; Kotov, D. O.; Safonov, A. S.; Ivanishchev, D. A.; Riabov, V. G.; Riabov, Yu. G.; Samsonov, V. M.

    2016-01-22

    Collisions of asymmetric nuclei (Cu+Au) differ essentially from the case of symmetric nuclei (Cu+Cu, Au+Au) collisions in the geometry of overlap region. This leads to a number of consequences, which provide more absolute and accurate information about fundamental properties of matter under extreme conditions. Nuclear modification factors for π-mesons in Cu+Au interactions at 200 GeV were measured in PHENIX Experiment at RHIC. New experimental data on measurement of flows of different order (v{sub 1}, v{sub 2}) for light hadrons in Cu+Au interactions at 200 GeV will be discussed in this paper.

  6. Experiment definition phase shuttle laboratory LDRL 10.6 experiment

    NASA Technical Reports Server (NTRS)

    1974-01-01

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

  7. Freeze Drying of Fruits and Vegetables: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Noble, Richard D.

    1979-01-01

    Describes a laboratory experiment for freeze-drying fruits and vegetables which aims to expose college students to the principles of drying and simultaneous heat and mass transfer. The experimental apparatus, procedure of the experiment, and data analysis are also included. (HM)

  8. Freeze Drying of Fruits and Vegetables: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Noble, Richard D.

    1979-01-01

    Describes a laboratory experiment for freeze-drying fruits and vegetables which aims to expose college students to the principles of drying and simultaneous heat and mass transfer. The experimental apparatus, procedure of the experiment, and data analysis are also included. (HM)

  9. Glycosidation of Methanol with Ribose: An Interdisciplinary Undergraduate Laboratory Experiment

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

  10. In Situ Techniques for Monitoring Electrochromism: An Advanced Laboratory Experiment

    ERIC Educational Resources Information Center

    Saricayir, Hakan; Uce, Musa; Koca, Atif

    2010-01-01

    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…

  11. In Situ Techniques for Monitoring Electrochromism: An Advanced Laboratory Experiment

    ERIC Educational Resources Information Center

    Saricayir, Hakan; Uce, Musa; Koca, Atif

    2010-01-01

    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…

  12. Glycosidation of Methanol with Ribose: An Interdisciplinary Undergraduate Laboratory Experiment

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

  13. Wiki Laboratory Notebooks: Supporting Student Learning in Collaborative Inquiry-Based Laboratory Experiments

    ERIC Educational Resources Information Center

    Lawrie, Gwendolyn Angela; Grøndahl, Lisbeth; Boman, Simon; Andrews, Trish

    2016-01-01

    Recent examples of high-impact teaching practices in the undergraduate chemistry laboratory that include course-based undergraduate research experiences and inquiry-based experiments require new approaches to assessing individual student learning outcomes. Instructors require tools and strategies that can provide them with insight into individual…

  14. Wiki Laboratory Notebooks: Supporting Student Learning in Collaborative Inquiry-Based Laboratory Experiments

    ERIC Educational Resources Information Center

    Lawrie, Gwendolyn Angela; Grøndahl, Lisbeth; Boman, Simon; Andrews, Trish

    2016-01-01

    Recent examples of high-impact teaching practices in the undergraduate chemistry laboratory that include course-based undergraduate research experiences and inquiry-based experiments require new approaches to assessing individual student learning outcomes. Instructors require tools and strategies that can provide them with insight into individual…

  15. The student perspective of high school laboratory experiences

    NASA Astrophysics Data System (ADS)

    Lambert, R. Mitch

    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 survey of high school science students, garnering 665 responses. Twelve student interviews then focused on the data and questions evolving from the survey. The student perspective on laboratory experiences revealed varied information based on individual experience. Concurrent analysis of the data revealed that although most students like (348/665) or sometimes like (270/665) these experiences, some consistent factors yielded negative experiences and prompted suggestions for improvement. The category of responses that emerged as the core idea focused on student understanding of the experience. Students desire to understand the why do, the how to, and the what it means of laboratory experiences. Lacking any one of these, the experience loses educational value for them. This single recurring theme crossed the boundaries of age, level in school, gender, and even the student view of lab experiences as positive or negative. This study suggests reflection on the current laboratory activities in which science teachers engage their students. Is the activity appropriate (as opposed to being merely a favorite), does it encourage learning, does it fit, does it operate at the appropriate level of inquiry, and finally what can science teachers do to integrate these activities into the classroom curriculum more effectively? Simply stated, what can teachers do so that students understand what to do, what's the point, and how that point fits into what they are learning outside the laboratory?

  16. Development of Laboratory Seismic Exploration Experiment for Education and Demonstration

    NASA Astrophysics Data System (ADS)

    Kuwano, O.; Nakanishi, A.

    2016-12-01

    We developed a laboratory experiment to simulate a seismic refraction survey for educational purposes. The experiment is tabletop scaled experiment using the soft hydrogel as an analogue material of a layered crust. So, we can conduct the seismic exploration experiment in a laboratory or a classroom. The softness and the transparency of the gel material enable us to observe the wave propagation with our naked eyes, using the photoelastic technique. By analyzing the waveforms obtained by the image analysis of the movie of the experiment, one can estimate the velocities and the structure of the gel specimen in the same way as an actual seismic survey. We report details of the practical course and the public outreach activities using the experiment.

  17. Neutrino-atom collisions

    NASA Astrophysics Data System (ADS)

    Kouzakov, Konstantin A.; Studenikin, Alexander I.

    2016-05-01

    Neutrino-atom scattering provides a sensitive tool for probing nonstandard interactions of massive neutrinos in laboratory measurements. The ionization channel of this collision process plays an important role in experiments searching for neutrino magnetic moments. We discuss some theoretical aspects of atomic ionization by massive neutrinos. We also outline possible manifestations of neutrino electromagnetic properties in coherent elastic neutrino-nucleus scattering.

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  19. Operating Experience of the Tritium Laboratory at CRL

    SciTech Connect

    Gallagher, C.L.; McCrimmon, K.D.

    2005-07-15

    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.

  20. CSI flight experiment projects of the Naval Research Laboratory

    NASA Technical Reports Server (NTRS)

    Fisher, Shalom

    1993-01-01

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

  1. CSI flight experiment projects of the Naval Research Laboratory

    NASA Astrophysics Data System (ADS)

    Fisher, Shalom

    1993-02-01

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

  2. Vibrational energy transfer in molecular collisions andvan der Waals clusters: Experiments and trajectory calculations

    NASA Astrophysics Data System (ADS)

    Yoder, Laurie Miller

    2000-09-01

    Polyatomic molecules with significant amounts of vibrational energy have high state densities that preclude state-to-state energy transfer observations. Both experiments and calculations are used to quantify energy transfer within this energy continuum. The work focuses on vibrationally excited aromatic molecules containing 10 to 15 atoms (pyrazine, benzene, methylpyrazine, toluene, pyrimidine, and aniline). In collisional experiments, the average vibrational energy of hot molecules was monitored by infrared fluorescence as they were deactivated by collisions with the bath. The experimental data were modeled with master equation simulations. The results for pyrazine show that the temperature dependence of the energy transfer is weak, and the average energy transferred per collision is approximately linearly dependent on vibrational energy. The experimental data cannot be modeled without invoking a biexponential collision step-size distribution, which implies that ``supercollisions,'' or very strongly deactivating collisions, are important. Additional information on the dynamics of energy transfer can be obtained through the vibrational predissociation of van der Waals dimers, which is the half-collision analog of a full collision. The ion imaging technique and a velocity-resolved time-of-flight technique were used to quantify the recoil energy released in the vibrational predissociation of triplet state mixed van der Waals dimers which contain ~2000 to ~8000 cm-1 of vibrational energy. The resulting recoil energy distributions peak near zero energy and are monotonically decreasing functions of energy. The fraction of initially available vibrational energy that appears as recoil energy is small. The average recoil energy is not strongly dependent on the initial vibrational energy or the density of states of the aromatic donor. Completely statistical models are unable to describe the results. Vibrational energy transfer both in van der Waals cluster predissociation

  3. A Model for Designing Adaptive Laboratory Evolution Experiments.

    PubMed

    LaCroix, Ryan A; Palsson, Bernhard O; Feist, Adam M

    2017-04-15

    The occurrence of mutations is a cornerstone of the evolutionary theory of adaptation, capitalizing on the rare chance that a mutation confers a fitness benefit. Natural selection is increasingly being leveraged in laboratory settings for industrial and basic science applications. Despite increasing deployment, there are no standardized procedures available for designing and performing adaptive laboratory evolution (ALE) experiments. Thus, there is a need to optimize the experimental design, specifically for determining when to consider an experiment complete and for balancing outcomes with available resources (i.e., laboratory supplies, personnel, and time). To design and to better understand ALE experiments, a simulator, ALEsim, was developed, validated, and applied to the optimization of ALE experiments. The effects of various passage sizes were experimentally determined and subsequently evaluated with ALEsim, to explain differences in experimental outcomes. Furthermore, a beneficial mutation rate of 10(-6.9) to 10(-8.4) mutations per cell division was derived. A retrospective analysis of ALE experiments revealed that passage sizes typically employed in serial passage batch culture ALE experiments led to inefficient production and fixation of beneficial mutations. ALEsim and the results described here will aid in the design of ALE experiments to fit the exact needs of a project while taking into account the resources required and will lower the barriers to entry for this experimental technique.IMPORTANCE ALE is a widely used scientific technique to increase scientific understanding, as well as to create industrially relevant organisms. The manner in which ALE experiments are conducted is highly manual and uniform, with little optimization for efficiency. Such inefficiencies result in suboptimal experiments that can take multiple months to complete. With the availability of automation and computer simulations, we can now perform these experiments in an optimized

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

    NASA Astrophysics Data System (ADS)

    Gaddis, Barbara A.

    2001-12-01

    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

  5. Whitson retrieves an experiment cartridge for the ZCG experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-10-29

    ISS005-E-19049 (29 October 2002) --- Astronaut Peggy A. Whitson, Expedition Five flight engineer, retrieves an experiment cartridge for the Zeolite Crystal Growth (ZCG) experiment in Destiny laboratory on the International Space Station (ISS).

  6. Argumentation in the Chemistry Laboratory: Inquiry and Confirmatory Experiments

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2003-03-01

    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.

  8. Dynamos: from an astrophysical model to laboratory experiments

    NASA Astrophysics Data System (ADS)

    Sokoloff, D. D.; Stepanov, R. A.; Frick, P. G.

    2014-03-01

    Magnetic field generation and evolution in celestial bodies—the subject matter of the theory of the dynamo—held Ya B Zeldovich's interest for years. Over the time since then, the study of the dynamo process has developed from a part of astrophysics and geophysics to a self-contained domain of physics, with the possibility of laboratory dynamo physics experiments. We give some theoretical background and discuss laboratory dynamo experiments (including those conducted in Russia), as well as their impact on dynamo theory and its astrophysical applications.

  9. On integrating LES and laboratory turbulent flow experiments

    SciTech Connect

    Grinstein, Fernando Franklin

    2008-01-01

    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.

  10. On integrating large eddy simulation and laboratory turbulent flow experiments.

    PubMed

    Grinstein, Fernando F

    2009-07-28

    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.

  11. The microphysics of ash tribocharging: New insights from laboratory experiments

    NASA Astrophysics Data System (ADS)

    Joshua, M. S.; Dufek, J.

    2014-12-01

    The spectacular lightning strokes observed during eruptions testify to the enormous potentials that can be generated within plumes. Related to the charging of individual ash particles, large electric fields and volcanic lightning have been observed at Eyjafjallajokull, Redoubt, and Sakurajima, among other volcanoes. A number of mechanisms have been proposed for plume electrification, including charging from the brittle failure of rock, charging due to phase change as material is carried aloft, and triboelectric charging, also known as contact charging. While the first two mechanisms (fracto-emission and volatile charging) have been described by other authors (James et al, 2000 and McNutt et al., 2010, respectively), the physics of tribocharging--charging related to the collisions of particles--of ash are still relatively unknown. Because the electric fields and lightning present in volcanic clouds result from the multiphase dynamics of the plume itself, understanding the electrodynamics of these systems may provide a way to detect eruptions and probe the interior of plumes remotely. In the present work, we describe two sets of experiments designed to explore what controls the exchange of charge during particle collisions. We employ natural material from Colima, Mt. Saint Helens, and Tungurahua. Our experiments show that the magnitude and temporal behavior of ash charging depend on a number of factors, including particle size, shape, chemistry, and collisional energy. The first set of experiments were designed to determine the time-dependent electrostatic behavior of a parcel of ash. These experiments consist of fluidizing an ash bed and monitoring the current induced in a set of ring electrodes. As such, we are able to extract charging rates for ash samples driven by different flow rates. The second experimental setup allows us to measure how much charge is exchanged during a single particle-particle collision. Capable of measuring charges as small as 1 fC, this

  12. Development of sensorial experiments and their implementation into undergraduate laboratories

    NASA Astrophysics Data System (ADS)

    Bromfield Lee, Deborah Christina

    "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

  13. Large-size space laboratory for biological orbit experiments.

    PubMed

    Kondyurin, A

    2001-01-01

    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.

  14. Dynamics of Protonated Peptide Ion Collisions with Organic Surfaces: Consonance of Simulation and Experiment

    SciTech Connect

    Pratihar, Subha; Barnes, George L.; Laskin, Julia; Hase, William L.

    2016-08-18

    In this Perspective mass spectrometry experiments and chemical dynamics simulations are described which have explored the atomistic dynamics of protonated peptide ions, peptide-H+, colliding with organic surfaces. These studies have investigated surface-induced dissociation (SID) for which peptide-H+ fragments upon collision with the surface, peptide-H+ physisorption on the surface, soft landing (SL), and peptide-H+ reaction with the surface, reactive landing (RL). The simulations include QM+MM and QM/MM direct dynamics. For collisions with self-assembled monolayer (SAM) surfaces there is quite good agreement between experiment and simulation in the efficiency of energy transfer to the peptide-H+ ion’s internal degrees of freedom. Both the experiments and simulations show two mechanisms for peptide-H+ fragmentation, i.e. shattering and statistical, RRKM dynamics. Mechanisms for SL are probed in simulations of collisions of protonated dialanine with a perfluorinated SAM surface. RL has been studied experimentally for a number of peptide-H+ + surface systems, and qualitative agreement between simulation and experiment is found for two similar systems.

  15. Combustion experiments in a zero-gravity laboratory

    NASA Technical Reports Server (NTRS)

    Cochran, T. H.

    1981-01-01

    One of the payloads that the Shuttle will carry into low-earth orbit is the Spacelab, a laboratory designed by a European consortium which will enable scientist-astronauts to conduct research in a shirt-sleeve environment. The typical flight of seven days will permit numerous experiments to be conducted that take advantage of long-term reduced gravity. A description is presented of plans for the conduction of Spacelab experiments which are related to the study of combustion, taking into account also investigations performed in the preparation of such experiments. Attention is given to an overview study of combustion experiments in a space laboratory, droplet burning, flammability limits in a standard tube, the combustion of particle clouds, smoldering combustion in porous fuels, liquid pool burning, and combustion experimentation aboard the space transportation system.

  16. Simulations of Laboratory Astrophysics Experiments using the CRASH code

    NASA Astrophysics Data System (ADS)

    Trantham, Matthew; Kuranz, Carolyn; Manuel, Mario; Keiter, Paul; Drake, R. P.

    2014-10-01

    Computer simulations can assist in the design and analysis of laboratory astrophysics experiments. The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan developed a code that has been used to design and analyze high-energy-density experiments on OMEGA, NIF, and other large laser facilities. This Eulerian code uses block-adaptive mesh refinement (AMR) with implicit multigroup radiation transport, electron heat conduction and laser ray tracing. This poster/talk will demonstrate some of the experiments the CRASH code has helped design or analyze including: Kelvin-Helmholtz, Rayleigh-Taylor, imploding bubbles, and interacting jet experiments. 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-NA0001840, and by the National Laser User Facility Program, Grant Number DE-NA0000850.

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

    NASA Astrophysics Data System (ADS)

    Yamada, M.

    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

  18. Rotationally inelastic collisions of He and Ar with NaK: Theory and Experiment

    NASA Astrophysics Data System (ADS)

    Richter, K.; Price, T. J.; Jones, J.; Faust, C.; Hickman, A. P.; Huennekens, J.; Malenda, R. F.; Ross, A. J.; Harker, H.; Crozet, P.; Forrey, R. C.

    2015-05-01

    Rotationally inelastic collisions of NaK A1Σ+ molecules with He and Ar are studied. At Lehigh, we use pump-probe polarization labeling (PL) and laser-induced fluorescence (LIF) spectroscopy. At Lyon, Fourier transform (FT)-resolved LIF spectra are recorded. In both cases, the pump laser excites a particular ro-vibrational level A1Σ+ (v , J). We observe strong direct lines corresponding to transitions from the (v , J) level pumped, and weak satellite lines corresponding to transitions from collisionally-populated levels (v ,J' = J + ΔJ). The ratios of satellite to direct line intensities in LIF and PL yield population and orientation transfer information. A strong propensity for ΔJ = even transitions is observed for both He and Ar perturbers. In the FT fluorescence experiment we also observe v-changing collisions. Ab initio potential surface and scattering calculations are underway for collisions in the A1Σ+ and X1Σ+ states. For He-NaK we have calculated potential surfaces using GAMESS and carried out coupled channel scattering calculations of transfer of population, orientation, and alignment. Calculations of v-changing collision cross sections are also in progress. Work supported by NSF, XSEDE and CNRS (PICS).

  19. Dispersion in acoustic waveguides-A teaching laboratory experiment

    NASA Astrophysics Data System (ADS)

    Meykens, K.; Van Rompaey, B.; Janssen, H.

    1999-05-01

    A laboratory experiment for undergraduate students in mathematics and physics is introduced. The experiment concentrates on dispersion in acoustic waveguides. The dispersion relation is measured for different propagation modes and its effect on the transmission of signals is examined, looking at it from several points of view, with the main focus on Fourier aspects. The distortion caused by single mode dispersion is explained in terms of the convolution relation between the input signals and the impulse response of the waveguides.

  20. Soap from Nutmeg: An Integrated Introductory Organic Chemistry Laboratory Experiment

    NASA Astrophysics Data System (ADS)

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

    2002-01-01

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

    See Letter re: this article.

  1. Laboratory experiments on magnetic reconnection and current systems

    NASA Astrophysics Data System (ADS)

    Stenzel, R. L.; Urrutia, J. M.; Gekelman, W.; Pfister, H.

    After a brief review of laboratory experiments involving magnetic reconnection a series of basic physics experiments on reconnection phenomena is described. These include magnetic annihilation, transport of magnetic energy by waves, stable and unstable current sheets, energy conversion mechanisms, and the role of global current systems vs. local reconnection processes. Current systems driven by electric fields resulting in particle flows are examined. Also, the role of a magnetic field component B(y) along the separator has been investigated.

  2. Development of Sensorial Experiments and Their Implementation into Undergraduate Laboratories

    ERIC Educational Resources Information Center

    Bromfield Lee, Deborah Christina

    2009-01-01

    "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…

  3. Raising environmental awareness through applied biochemistry laboratory experiments.

    PubMed

    Salman Ashraf, S

    2013-01-01

    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.

  4. Development of Sensorial Experiments and Their Implementation into Undergraduate Laboratories

    ERIC Educational Resources Information Center

    Bromfield Lee, Deborah Christina

    2009-01-01

    "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…

  5. Differentiating Biochemistry Course Laboratories Based on Student Experience

    ERIC Educational Resources Information Center

    Jakubowski, Henry V.

    2011-01-01

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

  6. Computer Simulation of Laboratory Experiments: An Unrealized Potential.

    ERIC Educational Resources Information Center

    Magin, D. J.; Reizes, J. A.

    1990-01-01

    Discussion of the use of computer simulation for laboratory experiments in undergraduate engineering education focuses on work at the University of New South Wales in the instructional design and software development of a package simulating a heat exchange device. The importance of integrating theory, design, and experimentation is also discussed.…

  7. Human Gene Discovery Laboratory: A Problem-Based Learning Experience

    ERIC Educational Resources Information Center

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

    2006-01-01

    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…

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

    ERIC Educational Resources Information Center

    Kusek, J. C.

    1980-01-01

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

  9. Women's Experiences in the Engineering Laboratory in Japan

    ERIC Educational Resources Information Center

    Hosaka, Masako

    2014-01-01

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

  10. The Science Laboratory Experiences of Utah's High School Students

    ERIC Educational Resources Information Center

    Campbell, Todd

    2007-01-01

    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…

  11. Women's Experiences in the Engineering Laboratory in Japan

    ERIC Educational Resources Information Center

    Hosaka, Masako

    2014-01-01

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

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

    ERIC Educational Resources Information Center

    Kusek, J. C.

    1980-01-01

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

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

    ERIC Educational Resources Information Center

    Collins, David C.

    2011-01-01

    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…

  14. Synthesis of Methyl Cyclopentanecarboxylate: A Laboratory Experience in Carbon Rearrangement

    ERIC Educational Resources Information Center

    Orchard, Alexandra; Maniquis, Roxanne V.; Salzameda, Nicholas T.

    2016-01-01

    We present a novel guided inquiry second semester organic chemistry laboratory rearrangement experiment. Students performed the Favorskii Rearrangement to obtain methyl cyclopentanecarboxylate in good yields. The students learned about the individual steps of the Favorskii mechanism and were required to propose a complete reaction mechanism and…

  15. Advanced Undergraduate Laboratory Experiment in Inelastic Electron Tunneling Spectroscopy.

    ERIC Educational Resources Information Center

    White, H. W.; Graves, R. J.

    1982-01-01

    An advanced undergraduate laboratory experiment in inelastic electron tunneling spectroscopy is described. Tunnel junctions were fabricated, the tunneling spectra of several molecules absorbed on the surface of aluminum oxide measured, and mode assignments made for several of the prominent peaks in spectra using results obtained from optical…

  16. An Enzyme Kinetics Experiment for the Undergraduate Organic Chemistry Laboratory

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

  17. Laboratory Experiment in Semiconductor Surface-Field Effects

    ERIC Educational Resources Information Center

    Goodman, F. R.; And Others

    1974-01-01

    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)

  18. Differentiating Biochemistry Course Laboratories Based on Student Experience

    ERIC Educational Resources Information Center

    Jakubowski, Henry V.

    2011-01-01

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

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

    ERIC Educational Resources Information Center

    Collins, David C.

    2011-01-01

    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…

  20. Human Gene Discovery Laboratory: A Problem-Based Learning Experience

    ERIC Educational Resources Information Center

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

    2006-01-01

    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…

  1. Synthesis of Methyl Cyclopentanecarboxylate: A Laboratory Experience in Carbon Rearrangement

    ERIC Educational Resources Information Center

    Orchard, Alexandra; Maniquis, Roxanne V.; Salzameda, Nicholas T.

    2016-01-01

    We present a novel guided inquiry second semester organic chemistry laboratory rearrangement experiment. Students performed the Favorskii Rearrangement to obtain methyl cyclopentanecarboxylate in good yields. The students learned about the individual steps of the Favorskii mechanism and were required to propose a complete reaction mechanism and…

  2. Laboratory Experiment in Semiconductor Surface-Field Effects

    ERIC Educational Resources Information Center

    Goodman, F. R.; And Others

    1974-01-01

    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)

  3. An Enzyme Kinetics Experiment for the Undergraduate Organic Chemistry Laboratory

    ERIC Educational Resources Information Center

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

    2010-01-01

    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…

  4. Implementing a laboratory automation system: experience of a large clinical laboratory.

    PubMed

    Lam, Choong Weng; Jacob, Edward

    2012-02-01

    Laboratories today face increasing pressure to automate their operations as they are challenged by a continuing increase in workload, need to reduce expenditure, and difficulties in recruitment of experienced technical staff. Was the implementation of a laboratory automation system (LAS) in the Clinical Biochemistry Laboratory at Singapore General Hospital successful? There is no simple answer, so the following topics comparing and contrasting pre- and post-LAS have been explored: turnaround time (TAT), laboratory errors, and staff satisfaction. The benefits and limitations of LAS from the laboratory experience were also reviewed. The mean TAT for both stat and routine samples decreased post-LAS (30% and 13.4%, respectively). In the 90th percentile TAT chart, a 29% reduction was seen in the processing of stat samples on the LAS. However, no significant difference in the 90th percentile TAT was observed with routine samples. It was surprising to note that laboratory errors increased post-LAS. Considerable effort was needed to overcome the initial difficulties associated with adjusting to a new system, new software, and new working procedures. Although some of the known advantages and limitations of LAS have been validated, the claimed benefits such as improvements in TAT, laboratory errors, and staff morale were not evident in the initial months.

  5. BOW SHOCK FRAGMENTATION DRIVEN BY A THERMAL INSTABILITY IN LABORATORY ASTROPHYSICS EXPERIMENTS

    SciTech Connect

    Suzuki-Vidal, F.; Lebedev, S. V.; Pickworth, L. A.; Swadling, G. F.; Skidmore, J.; Hall, G. N.; Bennett, M.; Bland, S. N.; Burdiak, G.; De Grouchy, P.; Music, J.; Suttle, L.; Ciardi, A.; Rodriguez, R.; Gil, J. M.; Espinosa, G.; Hartigan, P.; Hansen, E.; Frank, A.

    2015-12-20

    The role of radiative cooling during the evolution of a bow shock was studied in laboratory-astrophysics experiments that are scalable to bow shocks present in jets from young stellar objects. The laboratory bow shock is formed during the collision of two counterstreaming, supersonic plasma jets produced by an opposing pair of radial foil Z-pinches driven by the current pulse from the MAGPIE pulsed-power generator. The jets have different flow velocities in the laboratory frame, and the experiments are driven over many times the characteristic cooling timescale. The initially smooth bow shock rapidly develops small-scale nonuniformities over temporal and spatial scales that are consistent with a thermal instability triggered by strong radiative cooling in the shock. The growth of these perturbations eventually results in a global fragmentation of the bow shock front. The formation of a thermal instability is supported by analysis of the plasma cooling function calculated for the experimental conditions with the radiative packages ABAKO/RAPCAL.

  6. A Virtual Rock Physics Laboratory Through Visualized and Interactive Experiments

    NASA Astrophysics Data System (ADS)

    Vanorio, T.; Di Bonito, C.; Clark, A. C.

    2014-12-01

    As new scientific challenges demand more comprehensive and multidisciplinary investigations, laboratory experiments are not expected to become simpler and/or faster. Experimental investigation is an indispensable element of scientific inquiry and must play a central role in the way current and future generations of scientist make decisions. To turn the complexity of laboratory work (and that of rocks!) into dexterity, engagement, and expanded learning opportunities, we are building an interactive, virtual laboratory reproducing in form and function the Stanford Rock Physics Laboratory, at Stanford University. The objective is to combine lectures on laboratory techniques and an online repository of visualized experiments consisting of interactive, 3-D renderings of equipment used to measure properties central to the study of rock physics (e.g., how to saturate rocks, how to measure porosity, permeability, and elastic wave velocity). We use a game creation system together with 3-D computer graphics, and a narrative voice to guide the user through the different phases of the experimental protocol. The main advantage gained in employing computer graphics over video footage is that students can virtually open the instrument, single out its components, and assemble it. Most importantly, it helps describe the processes occurring within the rock. These latter cannot be tracked while simply recording the physical experiment, but computer animation can efficiently illustrate what happens inside rock samples (e.g., describing acoustic waves, and/or fluid flow through a porous rock under pressure within an opaque core-holder - Figure 1). The repository of visualized experiments will complement lectures on laboratory techniques and constitute an on-line course offered through the EdX platform at Stanford. This will provide a virtual laboratory for anyone, anywhere to facilitate teaching/learning of introductory laboratory classes in Geophysics and expand the number of courses

  7. Modeling Laboratory Astrophysics Experiments using the CRASH code

    NASA Astrophysics Data System (ADS)

    Trantham, Matthew; Drake, R. P.; Grosskopf, Michael; Bauerle, Matthew; Kruanz, Carolyn; Keiter, Paul; Malamud, Guy; Crash Team

    2013-10-01

    The understanding of high energy density systems can be advanced by laboratory astrophysics experiments. Computer simulations can assist in the design and analysis of these experiments. The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan developed a code that has been used to design and analyze high-energy-density experiments on OMEGA, NIF, and other large laser facilities. This Eulerian code uses block-adaptive mesh refinement (AMR) with implicit multigroup radiation transport and electron heat conduction. This poster/talk will demonstrate some of the experiments the CRASH code has helped design or analyze including: Radiative shocks experiments, Kelvin-Helmholtz experiments, Rayleigh-Taylor experiments, plasma sheet, and interacting jets experiments. 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.

  8. Experiences and Prospects of Nuclear Astrophysics in Underground Laboratories

    NASA Astrophysics Data System (ADS)

    Junker, M.

    2016-01-01

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

  9. Experiences and prospects of nuclear astrophysics in underground laboratories

    SciTech Connect

    Junker, M.

    2014-05-09

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

  10. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated June 22, 1988: 'A dwarf wheat variety known as Yecoro Rojo flourishes in KSC's Biomass Production Chamber. Researchers are gathering information on the crop's ability to produce food, water and oxygen, and then remove carbon dioxide. The confined quarters associated with space travel require researchers to focus on smaller plants that yield proportionately large amounts of biomass. This wheat crop takes about 85 days to grow before harvest.' Plant experiments such as this are the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  11. An undergraduate laboratory experiment on quantized conductance in nanocontacts

    NASA Astrophysics Data System (ADS)

    Foley, E. L.; Candela, D.; Martini, K. M.; Tuominen, M. T.

    1999-05-01

    We describe an undergraduate laboratory experiment on conductance steps observed to occur near integer multiples of 2e2/h as nanocontacts form and break between gold wires in loose contact. This experimental arrangement was first described by Costa-Krämer et al. [Surf. Sci. 342, L1144 (1995)]. A simple op-amp circuit in conjunction with an inexpensive storage oscilloscope suffice to observe the steps. The experiment may be extended by interfacing to a computer, which accumulates a histogram of conductance values as the wires are brought into and out of contact many times. The histogram shows peaks near integer multiples of 2e2/h. We emphasize the pedagogical issues involved in bringing an experiment from forefront condensed-matter physics research into the undergraduate laboratory.

  12. Laboratory experiments on the dynamics of the core

    NASA Astrophysics Data System (ADS)

    Olson, Peter

    2011-07-01

    Many innovative laboratory experiments have been used to investigate the fluid dynamics of the Earth's core. Experiments with liquid metals and non-metals range from turbulence and waves in the outer core to creeping flow in the inner core, and include the effects of rotation (steady and variable), thermal and chemical convection, spherical geometry, magnetic fields, melting and solidification. In this review, the strengths and limitations of laboratory fluid experiments are analyzed by comparing their dynamical similarity with the corresponding geophysical processes in the core. Recent advances in several areas are highlighted, including variable rotation dynamics, convection in liquid metals, the effects of magnetic fields on fluid motions, experimental dynamos, flow in the solid inner core, and metal-silicate interactions during core formation.

  13. Laboratory Experiments on the Dynamics of the Core

    NASA Astrophysics Data System (ADS)

    Olson, Peter

    2011-08-01

    Many innovative laboratory experiments have been used to investigate the fluid dynamics of the Earth's core. Experiments with liquid metals and non-metals range from turbulence and waves in the outer core to creeping flow in the inner core, and include the effects of rotation (steady and variable), thermal and chemical convection, spherical geometry, magnetic fields, melting and solidification. In this review, the strengths and limitations of laboratory fluid experiments are analyzed by comparing their dynamical similarity with the corresponding geophysical processes in the core. Recent advances in several areas are highlighted, including variable rotation dynamics, convection in liquid metals, the effects of magnetic fields on fluid motions, experimental dynamos, flow in the solid inner core, and metal-silicate interactions during core formation.

  14. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Original photo and caption dated June 22, 1988: 'A dwarf wheat variety known as Yecoro Rojo flourishes in KSC's Biomass Production Chamber. Researchers are gathering information on the crop's ability to produce food, water and oxygen, and then remove carbon dioxide. The confined quarters associated with space travel require researchers to focus on smaller plants that yield proportionately large amounts of biomass. This wheat crop takes about 85 days to grow before harvest.' Plant experiments such as this are the type of life sciences research that will be conducted at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  15. Numerical support of laboratory experiments: Attenuation and velocity estimations

    NASA Astrophysics Data System (ADS)

    Saenger, Erik; Madonna, Claudio; Frehner, Marcel; Almqvist, Bjarne

    2014-02-01

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

  16. Accreditation experience of radioisotope metrology laboratory of Argentina.

    PubMed

    Iglicki, A; Milá, M I; Furnari, J C; Arenillas, P; Cerutti, G; Carballido, M; Guillén, V; Araya, X; Bianchini, R

    2006-01-01

    This work presents the experience developed by the Radioisotope Metrology Laboratory (LMR), of the Argentine National Atomic Energy Commission (CNEA), as result of the accreditation process of the Quality System by ISO 17025 Standard. Considering the LMR as a calibration laboratory, services of secondary activity determinations and calibration of activimeters used in Nuclear Medicine were accredited. A peer review of the (alpha/beta)-gamma coincidence system was also carried out. This work shows in detail the structure of the quality system, the results of the accrediting audit and gives the number of non-conformities detected and of observations made which have all been resolved.

  17. Wiki Laboratory Notebooks: Supporting Student Learning in Collaborative Inquiry-Based Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Lawrie, Gwendolyn Angela; Grøndahl, Lisbeth; Boman, Simon; Andrews, Trish

    2016-06-01

    Recent examples of high-impact teaching practices in the undergraduate chemistry laboratory that include course-based undergraduate research experiences and inquiry-based experiments require new approaches to assessing individual student learning outcomes. Instructors require tools and strategies that can provide them with insight into individual student contributions to collaborative group/teamwork throughout the processes of experimental design, data analysis, display and communication of their outcomes in relation to their research question(s). Traditional assessments in the form of laboratory notebooks or experimental reports provide limited insight into the processes of collaborative inquiry-based activities. A wiki environment offers a collaborative domain that can potentially support collaborative laboratory processes and scientific record keeping. In this study, the effectiveness of the wiki in supporting laboratory learning and assessment has been evaluated through analysis of the content and histories for three consenting, participating groups of students. The conversational framework has been applied to map the relationships between the instructor, tutor, students and laboratory activities. Analytics that have been applied to the wiki platform include: character counts, page views, edits, timelines and the extent and nature of the contribution by each student to the wiki. Student perceptions of both the role and the impact of the wiki on their experiences and processes have also been collected. Evidence has emerged from this study that the wiki environment has enhanced co-construction of understanding of both the experimental process and subsequent communication of outcomes and data. A number of features are identified to support success in the use of the wiki platform for laboratory notebooks.

  18. Development, Evaluation and Use of a Student Experience Survey in Undergraduate Science Laboratories: The Advancing Science by Enhancing Learning in the Laboratory Student Laboratory Learning Experience Survey

    NASA Astrophysics Data System (ADS)

    Barrie, Simon C.; Bucat, Robert B.; Buntine, Mark A.; Burke da Silva, Karen; Crisp, Geoffrey T.; George, Adrian V.; Jamie, Ian M.; Kable, Scott H.; Lim, Kieran F.; Pyke, Simon M.; Read, Justin R.; Sharma, Manjula D.; Yeung, Alexandra

    2015-07-01

    Student experience surveys have become increasingly popular to probe various aspects of processes and outcomes in higher education, such as measuring student perceptions of the learning environment and identifying aspects that could be improved. This paper reports on a particular survey for evaluating individual experiments that has been developed over some 15 years as part of a large national Australian study pertaining to the area of undergraduate laboratories-Advancing Science by Enhancing Learning in the Laboratory. This paper reports on the development of the survey instrument and the evaluation of the survey using student responses to experiments from different institutions in Australia, New Zealand and the USA. A total of 3153 student responses have been analysed using factor analysis. Three factors, motivation, assessment and resources, have been identified as contributing to improved student attitudes to laboratory activities. A central focus of the survey is to provide feedback to practitioners to iteratively improve experiments. Implications for practitioners and researchers are also discussed.

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

    NASA Technical Reports Server (NTRS)

    1972-01-01

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

  20. News on collectivity in Pb-Pb collisions from the ALICE experiment

    NASA Astrophysics Data System (ADS)

    Kim, D. J.

    2017-04-01

    The collective expansion of the color-deconfined fireball created in ultra-relativistic heavy-ion collisions maps the initial state of the quark-gluon plasma (QGP) to the final-state particle spectrum. The ALICE experiment has been leading important roles for completing the individual flow harmonic measurements at the highest energies to date as well as improving flow harmonic correlation techniques to understand the properties of the QGP and the full evolution of the heavy-ion collisions. In this article, a brief summary of the individual flow harmonic measurements, the details of the new observables developed in recent years from ALICE collaboration and their implications to future studies are discussed.

  1. The Effect of Guided-Inquiry Laboratory Experiments on Science Education Students' Chemistry Laboratory Attitudes, Anxiety and Achievement

    ERIC Educational Resources Information Center

    Ural, Evrim

    2016-01-01

    The study aims to search the effect of guided inquiry laboratory experiments on students' attitudes towards chemistry laboratory, chemistry laboratory anxiety and their academic achievement in the laboratory. The study has been carried out with 37 third-year, undergraduate science education students, as a part of their Science Education Laboratory…

  2. Scientific equity: experiments in laboratory education in Ghana.

    PubMed

    Osseo-Asare, Abena Dove

    2013-12-01

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

  3. Visualizing electromagnetic fields in laser-produced counterstreaming plasma experiments for collisionless shock laboratory astrophysics

    NASA Astrophysics Data System (ADS)

    Kugland, Nathan

    2012-10-01

    In astrophysical settings, large and stable structures often emerge from turbulent supersonic plasma flows. Examples include the cosmic magnetic field and the collisionless shocks [1] in supernova remnants. In a scaled environment created with the high power lasers at OMEGA EP, proton imaging shows that large, stable electromagnetic field structures arise within counterstreaming supersonic plasmas [2]. These field structures are large compared to the fundamental turbulence scale lengths of the plasma (e.g. the Debye length and the ion skin-depth), indicating a high degree of self-organization. These features remain in place from 4 to 7 ns, indicating a high degree of stability. At early times out to at least 8 ns, intra-jet ion collisions are strong (due to relatively low thermal velocities) but inter-jet ion collisions are rare (due to relatively high flow velocities), permitting the evolution of both hydrodynamic and collisionless plasma instabilities [3, 4]. This paper will present detailed results from our laboratory astrophysics experiments. Prepared by LLNL for US DOE under Contract DE-AC52-07NA27344.[4pt] [1] H. S. Park et al, HEDP, 8, 38 (2011).[0pt] [2] N.L. Kugland et al, submitted to Nature Physics (2012).[0pt] [3] J.S. Ross et al, Phys. Plas., 19, 056501 (2012).[0pt] [3] D.D. Ryutov et al, Phys. Plas., 19, 076532 (2012).

  4. Spectral probing of impact-generated vapor in laboratory experiments

    NASA Astrophysics Data System (ADS)

    Schultz, Peter H.; Eberhardy, Clara A.

    2015-03-01

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

  5. LABORATORY STUDY OF RATE COEFFICIENTS FOR H{sub 2}O:He INELASTIC COLLISIONS BETWEEN 20 AND 120 K

    SciTech Connect

    Tejeda, G.; Moreno, E.; Fernández, J. M.; Montero, S.; Carmona-Novillo, E.; Hernández, M. I.

    2015-01-01

    State-to-state rate coefficients for ortho-H{sub 2}O:He and para-H{sub 2}O:He inelastic collisions in the 20-120 K thermal range are investigated by means of an improved experimental procedure. This procedure is based on the use of a kinetic master equation (MEQ) which describes the evolution of populations of H{sub 2}O rotational levels along a supersonic jet of H{sub 2}O highly diluted in helium. The MEQ is expressed in terms of experimental observables and rate coefficients for H{sub 2}O:He inelastic collisions. The primary experimental observables are the local number density and the populations of the rotational energy levels of H{sub 2}O, quantities which are determined along the jet with unprecedented accuracy by means of Raman spectroscopy with high space resolution. Sets of rate coefficients from the literature and from present close-coupling calculations using two different potential energy surfaces (PESs) have been tested against the experiment. The Green et al. rate coefficients are up to 50% too low compared to the experiment, while most rates calculated here from the Hodges et al. PES and the Patkowski et al. PES are much closer to the experimental values. Experimental rates with an estimated accuracy on the order of 10% have been obtained for ortho-H{sub 2}O:He and para-H{sub 2}O:He inelastic collisions between 20 and 120 K by scaling and averaging the theoretical rates to the experiment.

  6. An Introductory Laboratory Exercise on Solution Preparation: A Rewarding Experience

    NASA Astrophysics Data System (ADS)

    Wang, M. Rachel

    2000-02-01

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

  7. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  8. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  9. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  10. Beryllium Drive Disc Characterization for Laboratory Astrophysics Experiments

    NASA Astrophysics Data System (ADS)

    Ditmar, J. R.; Drake, R. P.; Kuranz, C. C.; Grosskopf, M. J.

    2009-11-01

    Laboratory Astrophysics scales large-scale phenomena, such as core-collapse supernovae shocks, down to the sub-millimeter scale for investigation in a laboratory setting. In some experiments, targets are constructed with a 20μm thick beryllium disc attached to a polyimide tube. A shockwave is created by irradiating the Be disc with ˜ 4kJ of energy from the Omega Laser. The Be material is rolled into a 20μm sheet and then machined to a 2.5mm diameter. Characterizing the roughness and knowing if there are any major features on the initial surface could affect interpretations of data taken during experiments. Structure in the Beryllium discs could become an important parameter in future high-fidelity computer simulations. Surfaces were characterized with a Scanning Electron Microscope and an Atomic Force Microscope.

  11. Equipment qualification testing evaluation experiences at Sandia National Laboratories

    SciTech Connect

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

    1986-01-01

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

  12. Lopez-Alegria with TRAC experiment in Destiny laboratory

    NASA Image and Video Library

    2007-01-02

    ISS014-E-11061 (2 Jan. 2007) --- Astronaut Michael E. Lopez-Alegria, Expedition 14 commander and NASA space station science officer, works with the Test of Reaction and Adaptation Capabilities (TRAC) experiment in the Destiny laboratory of the International Space Station. The TRAC investigation will test the theory of brain adaptation during space flight by testing hand-eye coordination before, during and after the space flight.

  13. Radiative Shocks And Plasma Jets As Laboratory Astrophysics Experiments

    SciTech Connect

    Koenig, M.; Loupias, B.; Vinci, T.; Ozaki, N.; Benuzzi-Mounaix, A.; Rabec le Goahec, M.; Falize, E.; Bouquet, S.; Courtois, C.; Nazarov, W.; Aglitskiy, Y.; Faenov, A. Ya.; Pikuz, T.; Schiavi, A.

    2007-08-02

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

  14. The Underground Laboratory in South Korea : facilities and experiments

    NASA Astrophysics Data System (ADS)

    Kim, Yeongduk

    2017-01-01

    We have developed underground physics programs for last 15 years in South Korea. The scientific and technical motivation for this initiative was the lack of local facility of a large accelerator in Korea. Thanks to the large underground electric power generator in Yangyang area, we could construct a deep underground laboratory (Yangyang Laboratory, Y2L) and has performed some pioneering experiments for dark matter search and double beta decay experiments. Since year of 2013, a new research center in the Institute for Basic Science (IBS), Center for Underground Physics (CUP), is approved by the government and Y2L laboratory is managed by CUP. Due to the limited space in Y2L, we are proposing to construct a new deep underground laboratory where we can host larger scale experiments of next generation. The site is in an active iron mine, and will be made in 1100 meter underground with a space of about 2000 m2 by the end of 2019. I will describe the status and future plan for this underground laboratory. CUP has two main experimental programs. (1) Identification of dark matter : The annual modulation signal of DAMA/LIBRA experiment has been contradictory to many other experiments such as XENON100, LUX, and Super CDMS. Yale University and CUP (COSINE-100) experimentalists agreed to do an experiment together at the Y2L and recently commissioned a 100kg scale low background NaI(Tl) crystal experiment. In future, we will develop NaI(Tl) crystals with lower internal backgrounds and try to run identical detectors at both north and south hemisphere. Low mass WIMP search is also planned with a development of low temperature sensors coupled with highly scintillating crystals. (2) Neutrinoless double beta decay search : The mass of the lightest neutrino and the Majorana nature of the neutrinos are not determined yet. Neutrinoless double beta decay experiment can answer both of the questions directly, and ultra-low backgrounds and excellent energy resolution are critical to

  15. Differentiating biochemistry course laboratories based on student experience.

    PubMed

    Jakubowski, Henry V

    2011-01-01

    Content and emphases in undergraduate biochemistry courses can be readily tailored to accommodate the standards of the department in which they are housed, as well as the backgrounds of the students in the courses. A more challenging issue is how to construct laboratory experiences for a class with both chemistry majors, who usually have little or no experience with biochemical techniques and biology and biochemistry majors who do. This manuscript describes a strategy for differentiating biochemistry labs to meet the needs of students with differing backgrounds.

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

    SciTech Connect

    Johnson, B.

    1992-12-31

    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.

  17. Laboratory astrophysics experiments relating to ionising and weakly radiative shocks

    NASA Astrophysics Data System (ADS)

    Cross, Joseph; Foster, John; Graham, Peter; Busschaert, Clotilde; Charpentier, Nicolas; Danson, Colin; Doyle, Hugo; Drake, R. Paul; Falize, Emeric; Fyrth, Jim; Gumbrell, Edward; Koenig, Michel; Kuranz, Carolyn; Loupias, Berenice; Michaut, Claire; Patankar, Sid; Skidmore, Jonathan; Spindloe, Christopher; Tubman, Ellie; Woolsey, Nigel; Yurchak, Roman; Gregori, Gianluca

    2014-10-01

    The aim of the POLAR project is to simulate, in the laboratory, the accretion shock region of a magnetic cataclysmic variable binary star system. Scaling laws have shown that laser experiments can be related to astrophysical phenomena by matching relevant dimensionless parameters. As well as forming a reverse shock, relevant to the POLAR project, the experimental system is also likely formed of a weakly radiating shock and an ionisation front. Results from our experiment at the Orion Laser are presented here, alongside comparisons to simulation and the astrophysical case (of relevance to triggered star formation).

  18. Holographic study of a vibrating bell: An undergraduate laboratory experiment

    NASA Astrophysics Data System (ADS)

    Menou, Kristen; Audit, Benjamin; Boutillon, Xavier; Vach, Holger

    1998-05-01

    An experiment combining holography and musical acoustics is described. Structures of vibration modes of a bell are visualized by time-average holography under either acoustical or mechanical excitation. The vibration amplitude as measured by an accelerometer shows very good quantitative agreement with that determined from our holograms by fringe counting. An effect of degenerate level separation is shown in the mechanical case. It is argued that this experiment is not only very inexpensive for a physics laboratory already equipped for holography, but that it also strongly stimulates students to deepen their insight into a variety of different topics in applied physics.

  19. Women's experiences in the engineering laboratory in Japan

    NASA Astrophysics Data System (ADS)

    Hosaka, Masako

    2014-07-01

    This qualitative study aims to examine Japanese women undergraduate engineering students' experiences of interacting with departmental peers of the same year in the laboratory setting by using interview data of 32 final-year students at two modestly selective national universities in Japan. Expectation state theory that explains unequal relationship between men and women is used as a framework. Findings suggest that women generally had a discouraging experience while working with their male peers. Specifically, women participated less and lost confidence by comparing with the men who appeared to be confident and competent.

  20. Design of Laboratory Experiments to Study Photoionization Fronts

    NASA Astrophysics Data System (ADS)

    Gray, William James; Davis, Josh; Drake, R. Paul

    2017-06-01

    Here we present the theoretical foundation for a laboratory experiment to study photoionization fronts. Photoionization fronts play important roles in the formation and evolution of structure in the Universe. A properly designed experiment will have to control the recombination rate, electron impact ionization rate, and the initial thermal spectrum. We show that such an experiment can be designed, but requires the use of the largest high-energy-density laser facilities, such as Omega, Z, and NIF. We also show that prior experiments do not actually generate photoionization fronts, rather a heat front is produced by heat conductions. We show some initial simulation results of the current experimental design and characterize the ionization front.

  1. Perceived traffic risk for cyclists: the impact of near miss and collision experiences.

    PubMed

    Sanders, Rebecca L

    2015-02-01

    Though the percentage of people bicycling for transportation rose during the last decade, with an average increase in bicycle commuting of 47% (Flusche, 2012), still only 1% of all U.S. trips are made by bike (Flusche, 2010). Research suggests that people's concern regarding the risk of bicycling near traffic-namely the risk of being hit by a car-remain a significant barrier to widespread cycling. However, research has not disaggregated traffic risk to expose its many aspects and how they may affect bicyclists with differing skill levels, experiences, and behaviors. This study begins to address this gap in our understanding. Elaborating on results from an internet survey, this study examined various aspects of traffic risk among 406 potential and current bicyclists in the San Francisco Bay Area. The data indicate that perceived traffic risk negatively influences the decision to bicycle for potential and occasional bicyclists, although the influence decreases with cycling frequency. Additionally, cycling frequency seems to heighten awareness of traffic risk, particularly for cyclists who have experienced "near misses" or collisions. In particular, near misses were found to be (a) much more common than collisions and (b) more strongly associated than collisions with perceived traffic risk. The findings suggest that efforts targeting road user behaviors and roadway designs associated with these near misses could mitigate perceived and actual traffic risk for bicyclists, and thereby eventually help achieve higher cycling ridership.

  2. Rotationally inelastic collisions of He and Ar with NaK: Theory and Experiment

    NASA Astrophysics Data System (ADS)

    Richter, K.; Price, T.; Jones, J.; Faust, C.; Hickman, A. P.; Huennekens, J.; Malenda, R. F.; Ross, A. J.; Crozet, P.

    2014-05-01

    Rotationally inelastic collisions of NaK (A1Σ+) molecules with He and Ar have been studied. At Lehigh, we use a pump-probe scheme (the probe is scanned over transitions to the 31 Π state) with either polarization labeling (PL) or laser-induced fluorescence (LIF) spectroscopy. At Lyon, one-laser excitation is used with Fourier Transform (FT) fluorescence spectroscopy. In both cases, the pump laser excites a particular ro-vibrational level A1Σ+ (v , J). We observe strong direct lines corresponding to transitions from the (v , J) level pumped, and weak satellite lines corresponding to transitions from collisionally-populated levels (v ,J' = J + ΔJ). The ratios of satellite to direct line intensities in LIF and PL yield information about population and orientation transfer. A strong propensity for ΔJ = even transitions is observed for both He and Ar perturbers. In the FT fluorescence experiment we also observe v changing collisions. Theoretical calculations are also underway for collisions in both the A1Σ+ and X1Σ+ states. For He-NaK we have calculated potential surfaces using GAMESS and carried out coupled channel scattering calculations of transfer of population, orientation, and alignment. Work supported by NSF, XSEDE and CNRS (PICS).

  3. An in silico DNA cloning experiment for the biochemistry laboratory.

    PubMed

    Elkins, Kelly M

    2011-01-01

    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 high school biology classes. Students begin by examining a plasmid map with the goal of identifying which restriction enzymes may be used to clone a piece of foreign DNA containing a gene of interest into the vector. From the National Center for Biotechnology Initiative website, students are instructed to retrieve a protein sequence and use Expasy's Reverse Translate program to reverse translate the protein to cDNA. Students then use Integrated DNA Technologies' OligoAnalyzer to predict the complementary DNA strand and obtain DNA recognition sequences for the desired restriction enzymes from New England Biolabs' website. Students add the appropriate DNA restriction sequences to the double-stranded foreign DNA for cloning into the plasmid and infecting Escherichia coli cells. Students are introduced to computational biology tools, molecular biology terminology and the process of DNA cloning in this valuable single session, in silico experiment. This project develops students' understanding of the cloning process as a whole and contrasts with other laboratory and internship experiences in which the students may be involved in only a piece of the cloning process/techniques. Students interested in pursuing postgraduate study and research or employment in an academic biochemistry or molecular biology laboratory or industry will benefit most from this experience.

  4. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  5. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  6. Armor breakup and reformation in a degradational laboratory experiment

    NASA Astrophysics Data System (ADS)

    Orrú, Clara; Blom, Astrid; Uijttewaal, Wim S. J.

    2016-06-01

    Armor breakup and reformation was studied in a laboratory experiment using a trimodal mixture composed of a 1 mm sand fraction and two gravel fractions (6 and 10 mm). The initial bed was characterized by a stepwise downstream fining pattern (trimodal reach) and a downstream sand reach, and the experiment was conducted under conditions without sediment supply. In the initial stage of the experiment an armor formed over the trimodal reach. The formation of the armor under partial transport conditions led to an abrupt spatial transition in the bed slope and in the mean grain size of the bed surface, as such showing similar results to a previous laboratory experiment conducted with a bimodal mixture. The focus of the current analysis is to study the mechanisms of armor breakup. After an increase in flow rate the armor broke up and a new coarser armor quickly formed. The breakup initially induced a bed surface fining due to the exposure of the finer substrate, which was accompanied by a sudden increase in the sediment transport rate, followed by the formation of an armor that was coarser than the initial one. The reformation of the armor was enabled by the supply of coarse material from the upstream degrading reach and the presence of gravel in the original substrate sediment. Here armor breakup and reformation enabled slope adjustment such that the new steady state was closer to normal flow conditions.

  7. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  8. Research and the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  9. Design of laboratory experiments to study radiation-driven implosions

    NASA Astrophysics Data System (ADS)

    Keiter, P. A.; Trantham, M.; Malamud, G.; Klein, S. R.; Davis, J.; VanDervort, R.; Shvarts, D.; Drake, R. P.; Stone, J. M.; Fraenkel, M.; Frank, Y.; Raicher, E.

    2017-03-01

    The interstellar medium is heterogeneous with dense clouds amid an ambient medium. Radiation from young OB stars asymmetrically irradiate the dense clouds. Bertoldi (1989) developed analytic formulae to describe possible outcomes of these clouds when irradiated by hot, young stars. One of the critical parameters that determines the cloud's fate is the number of photon mean free paths in the cloud. For the extreme cases where the cloud size is either much greater than or much less than one mean free path, the radiation transport should be well understood. However, as one transitions between these limits, the radiation transport is much more complex and is a challenge to solve with many of the current radiation transport models implemented in codes. We present the design of laboratory experiments that use a thermal source of x-rays to asymmetrically irradiate a low-density plastic foam sphere. The experiment will vary the density and hence the number of mean free paths of the sphere to study the radiation transport in different regimes. We have developed dimensionless parameters to relate the laboratory experiment to the astrophysical system and we show that we can perform the experiment in the same transport regime.

  10. A Ku-band laboratory experiment on the electromagnetic bias

    SciTech Connect

    Branger, H.; Ramamonjiarisoa, A.; Bliven, L.F.

    1993-11-01

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

  11. Inter-Laboratory Uranium Double-Spike Experiment

    SciTech Connect

    Russ, G. P

    1999-11-11

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

  12. Computational Modeling of Laboratory X-ray Emission due to Low-Energy Collisions of H-like and He-like ions with H2

    NASA Astrophysics Data System (ADS)

    Miller, Ansley; Mullen, Patrick Dean; Cumbee, Renata; Stancil, Phillip C.; Leutenegger, Maurice A.

    2016-06-01

    Charge exchange between highly-charged ions and neutral molecules occurs when the solar wind, or other astrophysical plasmas, collide with cool gas. This process emits observable X-rays with specific line intensities. Recent CX experiments at Lawrence Livermore National Laboratory measured the X-ray hardness ratios of low-energy collisions between hydrogen- and helium-like ions with H2 (Leutenegger et al. 2010). Using our recently developed X-ray modeling package, Kronos_v2 (Mullen et al. 2016), which utilizes multi-channel Landau-Zener charge exchange cross sections, we have computed theoretical hydrogen-like hardness ratios to aid in interpretation of the experimental data. While the computed hardness ratios are somewhat smaller than the experiment, it shows better agreement than earlier classical trajectory predictions. We are also in the process of building Kronos_v3; further enhancing the comprehensive charge exchange database to include helium-like and multielectron ions to allow for comparison with experiments and for models of hot astrophysical environments such as supernova remnants, star-forming galaxies, and galaxy clusters.Leutenegger, M. et al. 2010, Phys. Rev. Lett., 105, 063201Mullen, P. D. et al., 2016, ApJS, in press

  13. E917 experiment: Probing the dynamics of HI collisions + searching for the QGP

    SciTech Connect

    Ogilvie, C.A.; E917 Collaboration

    1996-12-31

    Experiment E917 has two main goals: to understand and probe the detailed mechanism of hadronic rescattering in HI collisions and to systematically search for a small volume of QGP. Correlated, discrete changes in sensitive QGP signatures as a function of both centrality and beam energy could indicate the presence of new physics. A precursor to the QGP is the possible change of hadronic properties in a dense medium. We will measure the {phi} and K{sup *} effective mass as a function of centrality to search for any change in the width or mass of these particles.

  14. Exploration of the Kinked Jet in the Crab Nebula with Scaled Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Li, Chikang

    2015-11-01

    X-ray images from the Chandra X-ray Observatory show that the South-East jet in the Crab nebula changes direction every few years. This remarkable phenomenon is also frequently observed for jets in other pulsar-wind nebulae and in other astrophysical objects. Numerical simulations suggest that it may be a consequence of current-driven, magnetohydrodynamic (MHD) instabilities taking place in the jet, yet that is just a hypothesis without verification in controlled experiments. To that end, we recently conducted scaled laboratory experiments that reproduced this phenomenon. In these experiments, a supersonic plasma jet was generated in the collision of two laser-produced plasma plumes, and this jet was radiographed from the side using 15-MeV and 3-MeV protons. It was observed that if self-generated toroidal magnetic fields around the jet were strong enough, they triggered plasma instabilities that caused substantial deflections throughout the jet propagation, mimicking the kinked jet structure seen in the Crab Nebula. We have modeled these laboratory experiments with comprehensive two- and three-dimensional numerical simulations, which in conjunction with the experiments provide compelling evidence that we have an accurate model of the most important physics of magnetic fields and MHD instabilities in the observed jet in the Crab Nebula. The work described here was performed in part at the LLE National Laser User's Facility (NLUF), and was supported in part by US DOE (Grant No. DE-FG03- 03SF22691), LLNL (subcontract Grant No. B504974) and LLE (subcontract Grant No. 412160-001G).

  15. Georgia Teachers in Academic Laboratories: Research Experiences in the Geosciences

    NASA Astrophysics Data System (ADS)

    Barrett, D.

    2005-12-01

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

  16. Cryogenic Fracturing: Laboratory Visualization Experiments and Numerical Simulations Using Peridynamics

    NASA Astrophysics Data System (ADS)

    Martin-Short, R.; Edmiston, J. K.

    2015-12-01

    Typical hydraulic fracturing operations involve the use of a large quantity of water, which can be problematic for several reasons including possible formation (permeability) damage, disposal of waste water, and the use of precious local water resource. An alternate reservoir permeability enhancing technology not requiring water is cryogenic fracturing. This method induces controlled fracturing of rock formations by thermal shock and has potentially important applications in the geothermal and hydrocarbon industries. In this process, cryogenic fluid—such as liquid nitrogen—is injected into the subsurface, causing fracturing due to thermal gradients. These fractures may improve the formation permeability relative to that achievable by hydraulic fracturing alone. We conducted combined laboratory visualization and numerical simulations studies of thermal-shock-induced fracture initiation and propagation resulting from liquid nitrogen injection in rock and analog materials. The experiment used transparent soda-lime glass cubes to facilitate real-time visualization of fracture growth and the fracture network geometry. In this contribution, we report the effect of overall temperature difference between cryogenic fluid and solid material on the produced fracture network, by pre-heating the glass cubes to several temperatures and injecting liquid nitrogen. Temperatures are monitored at several points by thermocouple and the fracture evolution is captured visually by camera. The experiment was modeled using a customized, thermoelastic, fracture-capable numerical simulation code based on peridynamics. The performance of the numerical code was validated by the results of the laboratory experiments, and then the code was used to study the different factors affecting a cryogenic fracturing operation, including the evolution of residual stresses and constitutive relationships for material failure. In complex rock such as shale, understanding the process of cryogenic

  17. The Heavy Photon Search experiment at Jefferson Laboratory

    SciTech Connect

    Celentano, Andrea

    2014-11-01

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

  18. Simulations of Laboratory Astrophysics Experiments using the CRASH code

    NASA Astrophysics Data System (ADS)

    Trantham, Matthew; Kuranz, Carolyn; Fein, Jeff; Wan, Willow; Young, Rachel; Keiter, Paul; Drake, R. Paul

    2015-11-01

    Computer simulations can assist in the design and analysis of laboratory astrophysics experiments. The Center for Radiative Shock Hydrodynamics (CRASH) at the University of Michigan developed a code that has been used to design and analyze high-energy-density experiments on OMEGA, NIF, and other large laser facilities. This Eulerian code uses block-adaptive mesh refinement (AMR) with implicit multigroup radiation transport, electron heat conduction and laser ray tracing. This poster will demonstrate some of the experiments the CRASH code has helped design or analyze including: Kelvin-Helmholtz, Rayleigh-Taylor, magnetized flows, jets, and laser-produced plasmas. This work is funded by the following grants: DEFC52-08NA28616, DE-NA0001840, and DE-NA0002032.

  19. Laboratory Experiments of High Mach Number Raditaive Jets

    NASA Astrophysics Data System (ADS)

    Frank, A.; Gardiner, T.; Blackman, E.; Lebedev, S.; Chittenden, J.; Beg, S.; Bland, S.; Ciardi, A.; Ampleford, D.; Hughes, S.; Haines, M. G.

    2001-05-01

    We present astrophysically relevent experiments on the generation of a highly supersonic plasma jet by a convergent plasma flow. The flow is produced by electrodynamic acceleration of plasma in a conical array of fine metallic wires (a modification of the wire array Z-pinch). Stagnation of the plasma flow on the axis of symmetry forms a standing conical shock, which effectively collimates the flow in the axial direction. This scenario is essentially similar to that discussed by Cantó et al 1988 as a possible, purely hydrodynamic mechanism of jet formation in young stellar objects. Experiments using different materials (Al, Fe and W) show that a highly supersonic (M 20) and a well-collimated jet is generated when the radiative cooling rate of the plasma is significant. The interaction of this jet with a plasma target could be used for scaled laboratory astrophysical experiments on hydrodynamic instabilities in decelerated plasma flow.

  20. Whitson works with experiment cartridge for the ZCG experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-10-29

    ISS005-E-19048 (29 October 2002) --- Astronaut Peggy A. Whitson, Expedition Five flight engineer, works with an experiment cartridge for the Zeolite Crystal Growth (ZCG) experiment in Destiny laboratory on the International Space Station (ISS). The autoclave for the ZCG is visible above.

  1. Rotationally inelastic collisions of He and Ar with NaK: Theory and Experiment

    NASA Astrophysics Data System (ADS)

    Price, T. J.; Towne, A. C.; Richter, K.; Jones, J.; Hickman, A. P.; Huennekens, J.; Faust, C.; Malenda, R. F.; Ross, A. J.; Crozet, P.; Talbi, D.; Forrey, R. C.

    2016-05-01

    Rotationally inelastic thermal collisions of NaK A1Σ+ molecules with He and Ar have been studied at Lehigh and Lyon. In both laboratories, a pump laser excites a particular ro-vibrational level A1Σ+ (v , J). Strong transitions from the pumped (v , J) level and weaker transitions from collisionally-populated levels (v ,J' = J + ΔJ) occur. Ratios of line intensities yield information about population and orientation transfer. At Lyon, we also identify v changing collisions. A strong propensity for ΔJ = even transitions is observed for He and Ar. Theoretical calculations are underway; we've calculated He-NaK and Ar-NaK potential surfaces using GAMESS and performed coupled channel scattering calculations for JM -->J'M' transitions. Semiclassical formulas for the cross sections have been obtained and agree well with our quantum mechanical calculations. Using the vector model, where J precesses with polar angle θ about the z-axis, we derived the distribution of final polar angles θ' and final M' states. We identify a special case where the θ' distribution is a Lorentzian centered at θ. Work supported by NSF, XSEDE and CNRS (PICS).

  2. The spacecraft control laboratory experiment optical attitude measurement system

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  3. Constraining PCP Violating Varying Alpha Theory through Laboratory Experiments

    SciTech Connect

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

    2012-06-06

    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.

  4. Elucidating GPR Response to Biological Activity: Field and Laboratory Experiments

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    Recent studies of the geophysical signatures of biological processes in earth environments have resulted in the emergent field of “biogeophysics”. The ability to monitor remotely and to quantify active biological processes in the subsurface can have transformative implications to a wide range of investigations, including the bioremediation of contaminated sites. Previous studies have demonstrated that ground-penetrating radar (GPR) can be used to detect the products of microbial activity in the subsurface, such as changes in bulk electrical conductivity, mineral dissolution and precipitation, and the formation of biogenic gas. We present field and laboratory experiments that offer insights to the response of GPR signals to microbial activity. In the field, time-lapse borehole radar tomography was used to monitor biodegradation of a hydrocarbon plume over a period of two years. A dense grid of fourteen borehole pairs monitoring the bioactive region showed radar wave velocity changes of +/-4% and signal attenuation changes of +/-25%. These GPR observations correlated spatially and temporally to independent measurements of groundwater velocity and geochemical variations that occurred in response to microbial activity. The greatest relative changes in radar wave velocity of propagation and attenuation were observed in the region of enhanced bacterial stimulation where biomass growth was the greatest. Radar wave velocity and attenuation decreased during periods of enhanced biostimulation. Two laboratory experiments were conducted to further assess radar response to biomass growth. The first experiment monitored GPR wave transmission through a water-saturated quartz-sand reactor during the course of enhanced biostimulation. Radar wave velocity initially decreased as a result of bacterial activity and subsequently increased rapidly as biogenic gas formed in the pore space. Radar signal attenuation increased during the course of the experiment as a result of an

  5. Lab-scale ash production by abrasion and collision experiments of porous volcanic samples

    NASA Astrophysics Data System (ADS)

    Mueller, S. B.; Lane, S. J.; Kueppers, U.

    2015-09-01

    In the course of explosive eruptions, magma is fragmented into smaller pieces by a plethora of processes before and during deposition. Volcanic ash, fragments smaller than 2 mm, has near-volcano effects (e.g. increasing mobility of PDCs, threat to human infrastructure) but may also cause various problems over long duration and/or far away from the source (human health and aviation matters). We quantify the efficiency of ash generation during experimental fracturing of pumiceous and scoriaceous samples subjected to shear and normal stress fields. Experiments were designed to produce ash by overcoming the yield strength of samples from Tenerife (Canary Islands, Spain), Sicily and Lipari Islands (Italy), with this study having particular interest in the < 355 μm fraction. Fracturing within volcanic conduits, plumes and pyroclastic density currents (PDCs) was simulated through a series of abrasion (shear) and collision (normal) experiments. An understanding of these processes is crucial as they are capable of producing very fine ash (< 10 μm). These particles can remain in the atmosphere for several days and may travel large distances (~ 1000s of km). This poses a threat to the aviation industry and human health. From the experiments we establish that abrasion produced the finest-grained material and up to 50% of the generated ash was smaller than 10 μm. In comparison, the collision experiments that applied mainly normal stress fields produced coarser grain sizes. Results were compared to established grain size distributions for natural fall and PDC deposits and good correlation was found. Energies involved in collision and abrasion experiments were calculated and showed an exponential correlation with ash production rate. Projecting these experimental results into the volcanic environment, the greatest amounts of ash are produced in the most energetic and turbulent regions of volcanic flows, which are proximal to the vent. Finest grain sizes are produced in PDCs

  6. Slab pull and indentation tectonics: insights from 3D laboratory experiments

    NASA Astrophysics Data System (ADS)

    Regard, Vincent; Faccenna, Claudio; Martinod, Joseph; Bellier, Olivier

    2005-03-01

    We investigate, using 3D laboratory experiments, how the dynamics of indentation process are affected by the evolution at depth of the oceanic and continental subductions. Lithospheric plates are modelled by sand-silicone plates floating on glucose syrup, and the density contrast between oceanic and continental lithospheric plates and asthenosphere is reproduced. Analogue experiments model the convergence between two lithospheric plates, a small continent indenting a large continental plate. We show that the surface deformation in front of the indenter and above the oceanic subduction zone depends on the behaviour of the slab below the collision zone. Slab break-off following the subduction of the small continent favours the indentation process, because it results in an increasing compression in front of the indenter, and extension above the neighbouring oceanic subduction, both of them being responsible for the appearance of the indenter-like geometry of the plate boundary. When the slab does not deform significantly at depth, in contrast, the closure of the oceanic domain in front of the indenter is followed by a longer period of continental subduction, during which the tectonic regime within the wide continent remains quite homogeneous. Comparing the presented analogue experiments with the subductions both part of the Arabian indenter within Eurasia, our results suggest that the different tectonic regime on both sides of the Arabia indenter may partly result from the probable occurrence of a detachment at depth under eastern Anatolia.

  7. Tandem time-of-flight experiment for low energy collision studies.

    PubMed

    Sublemontier, O; Poisson, L; Pradel, P; Mestdagh, J M; Visticot, J P

    2000-02-01

    We present an experiment adapted to collisional studies of cluster ions based on a laser vaporization setup coupled to a supersonic expansion. The ions are selected in a first time-of-flight, slowed down to the desired energy, and collided in an octopolar guide. The parent and fragment ions are then reaccelerated in order to be mass analyzed in a reflectron time-of-flight. An original method for the extraction of the ion that uses a double voltage pulse, is proposed. The experiment has been applied to collisions of hydrated cobalt ions. An absolute cross section of 17 A2 for the loss of one water molecule by Co(H2O)2+ in collision with neon at a center-of-mass energy of 10 eV, has been determined, with an accuracy of 10%. The threshold for this reaction has been measured at 1.5 eV and is in good agreement with the existing literature (Dalleska et al. J. Am. Chem. Soc. 1994, 116, 3519). Ions that cannot be formed by conventional ligand exchange methods, can also be studied. As an example, the threshold for dehydration of the Co2(H2O)+ ion has been measured at 1.5 +/- 0.2 eV.

  8. Studying collisions in the general physics laboratory with quadrature light emitting diode sensors

    NASA Astrophysics Data System (ADS)

    DeYoung, P. A.; Mulder, B.

    2002-12-01

    We have developed the means to measure position rapidly and precisely as a function of time in the general physics laboratory. These measurements are of sufficient quality that velocities and accelerations can be calculated from the position data using numerical derivatives. The precision of the measurements is such that any disagreement between theoretical expectations and experimental measurements is less than a few percent. Measurements of the system under study can be made as rapidly as every 200 μs, which is faster than the typical time scales over which the system changes. Measuring rapidly also allows one to investigate additional phenomena not previously accessible and to see features of the physics previously unobserved. The measurement system is based on commercially available sensors, computer hardware, and computer software (LABVIEW™). Many general physics laboratories based on this system have been developed but only an investigation of Newton's second law will be described here.

  9. Experiments at The Virtual National Laboratory for Heavy Ion Fusion

    SciTech Connect

    Seidl, P.A.; Bieniosek, F.M.; Celata, C.M.; Faltens, A.; Kwan, J.W.; MacLaren, S.A.; Ponce, D.; Shuman, D.; Yu, S.; Ahle, L.; Lund, S.; Molvik, A.; Sangster, T.C.

    2000-07-24

    An overview of experiments is presented, in which the physical dimensions, emittance and perveance are scaled to explore driver-relevant beam dynamics. Among these are beam merging, focusing to a small spot, and bending and recirculating beams. The Virtual National Laboratory for Heavy Ion Fusion (VNL) is also developing two driver-scale beam experiments involving heavy-ion beams with I(sub beam) about 1 Ampere to provide guidance for the design of an Integrated Research Experiment (IRE) for driver system studies within the next 5 years. Multiple-beam sources and injectors are being designed and a one-beam module will be built and tested. Another experimental effort will be the transport of such a beam through about 100 magnetic quadrupoles. The experiment will determine transport limits at high aperture fill factors, beam halo formation, and the influence on beam properties of secondary electron Research into driver technology will be briefly presented, including the development of ferromagnetic core materials, induction core pulsers, multiple-beam quadrupole arrays and plasma channel formation experiments for pinched transport in reactor chambers.

  10. Plasma interaction experiment 2 (PIX 2): Laboratory and flight results

    NASA Technical Reports Server (NTRS)

    Grier, N. T.

    1985-01-01

    The Plasma Interaction Experiments 1 and 2 (PIX 1 and 2) were designed as first steps toward understanding interactions between high-voltage solar arrays and the surrounding plasma. The PIX 2 consisted of an approximately 2000-sq cm array divided into four equal segments. Each of the segments could be biased independently and the current measured separately. In addition to the solar array segments, PIX 2 had a hot-wire-filament electron emitter and a spherical Langmuir probe. The emitter was operated when the array segments were biased positively bove 125 V. Thermal electrons from the emitter aided in balancing the electron currents collected by the array. Laboratory and flight results of PIX 2 are presented. At high positive voltages on the solar array segments, the flight currents were approximately an order of magnitude larger than the ground test currents. This is attributed to the tank walls in the laboratory interfering with the electron currents to the array segments. From previous tests it is known that the tank walls limit the electron currents at high voltages. This was the first verification of the extent of the laboratory tank effect on the plasma coupling current.

  11. Simulation studies of plasma lens experiments at Daresbury laboratory

    NASA Astrophysics Data System (ADS)

    Hanahoe, K.; Mete, O.; Xia, G.; Angal-Kalinin, D.; Jones, J.; Smith, J.

    2016-03-01

    Experiments are planned to study plasma lensing using the VELA and CLARA Front End accelerators at Daresbury Laboratory. This paper presents results of 2-dimensional particle-in-cell simulations of the proposed experiments. The variation in focusing strength and emittance growth with beam and plasma parameters are studied in the overdense (plasma density much greater than bunch density) regime for the VELA beam. The effect of spherical and longitudinal aberrations on the beam emittance was estimated through numerical and theoretical studies. Simulation results show that a focusing strength equivalent to a magnetic field gradient of 10 T m-1 can be achieved using VELA, and a gradient of 247 T m-1 can be achieved using CLARA Front End.

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

    PubMed Central

    Day, J.; McPherson, A.

    1992-01-01

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

  13. Clinical and laboratory experience of chorionic villous sampling in Nigeria.

    PubMed

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

    2014-01-01

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

  14. Laboratory plasma physics experiments using merging supersonic plasma jets

    DOE PAGES

    Hsu, S. C.; Moser, A. L.; Merritt, E. C.; ...

    2015-04-01

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

  15. Experiences of mentors training underrepresented undergraduates in the research laboratory.

    PubMed

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

    2013-01-01

    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.

  16. Laboratory plasma physics experiments using merging supersonic plasma jets

    SciTech Connect

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

    2015-04-01

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

  17. Salt dissolution and sinkhole formation: Results of laboratory experiments

    NASA Astrophysics Data System (ADS)

    Oz, Imri; Eyal, Shalev; Yoseph, Yechieli; Ittai, Gavrieli; Elad, Levanon; Haim, Gvirtzman

    2016-10-01

    The accepted mechanism for the formation of thousands of sinkholes along the coast of the Dead Sea suggests that their primary cause is dissolution of a salt layer by groundwater undersaturated with respect to halite. This is related to the drop in the Dead Sea level, which caused a corresponding drop of the freshwater-saltwater interface, resulting in fresher groundwater replacing the brines that were in contact with the salt layer. In this study we used physical laboratory experiments to examine the validity of this mechanism by reproducing the full dynamic natural process and to examine the impact of different hydrogeological characteristics on this process. The experimental results show surface subsidence and sinkhole formation. The stratigraphic configurations of the aquifer, together with the mechanical properties of the salt layer, determine the dynamic patterns of the sinkhole formation (instantaneous versus gradual formation). Laboratory experiments were also used to study the potential impact of future stratification in the Dead Sea, if and when the "Red Sea-Dead Sea Canal" project is carried out, and the Dead Sea level remains stable. The results show that the dissolution rates are slower by 1 order of magnitude in comparison with a nonstratified saltwater body, and therefore, the processes of salt dissolution and sinkhole formation will be relatively restrained under these conditions.

  18. Kinetics of Papain: An Introductory Biochemistry Laboratory Experiment

    NASA Astrophysics Data System (ADS)

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

    1999-05-01

    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.

  19. Asteroid Regolith Mechanical Properties: Laboratory Experiments With Cohesive Powders

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    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

  20. Laboratory Experiments and Instrument Intercomparison Studies of Carbonaceous Aerosol Particles

    SciTech Connect

    Davidovits, Paul

    2015-10-20

    Aerosols containing black carbon (and some specific types of organic particulate matter) directly absorb incoming light, heating the atmosphere. In addition, all aerosol particles backscatter solar light, leading to a net-cooling effect. Indirect effects involve hydrophilic aerosols, which serve as cloud condensation nuclei (CCN) that affect cloud cover and cloud stability, impacting both atmospheric radiation balance and precipitation patterns. At night, all clouds produce local warming, but overall clouds exert a net-cooling effect on the Earth. The effect of aerosol radiative forcing on climate may be as large as that of the greenhouse gases, but predominantly opposite in sign and much more uncertain. The uncertainties in the representation of aerosol interactions in climate models makes it problematic to use model projections to guide energy policy. The objective of our program is to reduce the uncertainties in the aerosol radiative forcing in the two areas highlighted in the ASR Science and Program Plan. That is, (1) addressing the direct effect by correlating particle chemistry and morphology with particle optical properties (i.e. absorption, scattering, extinction), and (2) addressing the indirect effect by correlating particle hygroscopicity and CCN activity with particle size, chemistry, and morphology. In this connection we are systematically studying particle formation, oxidation, and the effects of particle coating. The work is specifically focused on carbonaceous particles where the uncertainties in the climate relevant properties are the highest. The ongoing work consists of laboratory experiments and related instrument inter-comparison studies both coordinated with field and modeling studies, with the aim of providing reliable data to represent aerosol processes in climate models. The work is performed in the aerosol laboratory at Boston College. At the center of our laboratory setup are two main sources for the production of aerosol particles: (a

  1. Experiments on 1,000 km/s flyer acceleration and collisions

    NASA Astrophysics Data System (ADS)

    Karasik, Max; Weaver, J. L.; Aglitskiy, Y.; Kehne, D. M.; Zalesak, S. T.; Velikovich, A. L.; Oh, J.; Serlin, V.; Obenschain, S. P.

    2012-10-01

    We will present results from follow-on experiments to the record-high velocities achieved using the ultra-uniform deep-uv drive of the Nike KrF laser [Karasik et al, Phys. Plasmas 17, 056317 (2010)], in which highly accelerated planar foils of deuterated polystyrene were made to collide with a witness foil to produce ˜1 Gbar shock pressures and result in heating of matter to thermonuclear temperatures. Such velocities may indicate a path to lower minimum energy required for central ignition. Still higher velocities and higher target densities are required for impact fast ignition. New results give velocity of >1,100 km/s achieved through improvements in pulseshaping. Variation of second foil parameters results in significant change in fusion neutron production on impact. In-flight target density is inferred from target heating upon collision via DD neutron time-of-flight ion temperature measurement. Availability of pressures generated by collisions of such highly accelerated flyers may provide an experimental platform for study of matter at extreme conditions. Work is supported by US DOE (NNSA).

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

    NASA Technical Reports Server (NTRS)

    1972-01-01

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

  3. Hydration Energies of Zinc(II): Threshold Collision-Induced Dissociation Experiments and Theoretical Studies

    NASA Astrophysics Data System (ADS)

    Cooper, Theresa E.; Carl, D. R.; Armentrout, P. B.

    2009-11-01

    The first experimentally determined sequential bond dissociation energies of Zn2+(H2O)n complexes, where n = 6-10, are measured using threshold collision-induced dissociation in a guided ion beam tandem mass spectrometer coupled with an electrospray ionization source. Kinetic energy dependent cross sections are obtained and analyzed to yield 0 K threshold measurements for the loss of one and two water ligands after accounting for multiple collisions, kinetic shifts, and energy distributions. The threshold measurements are then converted from 0 to 298 K values to give the hydration energies for sequentially losing one water from each parent complex. Theoretical geometry optimizations and single-point energy calculations are performed using several levels of theory for comparison to experiment. Although different levels of theory disagree on the ground-state conformation of most complexes examined here leading to potential ambiguities in the final thermochemical values, calculations at the MP2(full) level provide the best agreement with experiment. On this basis, the present experiments are most consistent with the inner solvent shell of Zn2+ being five waters, except for Zn2+(H2O)6 where all waters bind directly to the metal ion. The charge separation process, Zn2+(H2O)n → ZnOH+(H2O)m + H+(H2O)n-m-1, which is in competition with the loss of water from the parent complex, is also observed for n = 6-8. These processes are analyzed in detail in the following paper.

  4. Laboratory astrophysical collisionless shock experiments with interpenetrating plasma flows on Omega and NIF

    NASA Astrophysics Data System (ADS)

    Ross, James; Park, H.-S.; Huntington, C.; Ryutov, D.; Drake, R. P.; Froula, D.; Gregori, G.; Levy, M.; Lamb, D.; Fiuza, F.; Petrasso, R.; Li, C.; Zylastra, A.; Rinderknecht, H.; Sakawa, Y.; Spitkovsky, A.

    2015-11-01

    Shock formation from high-Mach number plasma flows is observed in many astrophysical objects such as supernova remnants and gamma ray bursts. These are collisionless shocks as the ion-ion collision mean free path is much larger than the system size. It is believed that seed magnetic fields can be generated on a cosmologically fast timescale via the Weibel instability when such environments are initially unmagnetized. Here we present laboratory experiments using high-power lasers whose ultimate goal is to investigate the dynamics of collisionless shock formation in two interpenetrating plasma streams. Particle-in-cell numerical simulations have confirmed that the strength and structure of the generated magnetic field are consistent with the Weibel mediated electromagnetic nature and that the inferred magnetization level could be as high as ~ 1%. This paper will review recent experimental results from various laser facilities as well as the simulation results and the theoretical understanding of these observations. Taken together, these results imply that electromagnetic instabilities can be significant in both inertial fusion and astrophysical conditions. We will present results from initial NIF experiments, where we observe the neutrons and x-rays generated from the hot plasmas at the center of weakly collisional, counterstreaming flows. Prepared by LLNL under Contract DE-AC52-07NA27344.

  5. Patients' Experiences With Vehicle Collision to Inform the Development of Clinical Practice Guidelines: A Narrative Inquiry.

    PubMed

    Lindsay, Gail M; Mior, Silvano A; Côté, Pierre; Carroll, Linda J; Shearer, Heather M

    2016-01-01

    The purpose of this narrative inquiry was to explore the experiences of persons who were injured in traffic collisions and seek their recommendations for the development of clinical practice guideline (CPG) for the management of minor traffic injuries. Patients receiving care for traffic injuries were recruited from 4 clinics in Ontario, Canada resulting in 11 adult participants (5 men, 6 women). Eight were injured while driving cars, 1 was injured on a motorcycle, 2 were pedestrians, and none caused the collision. Using narrative inquiry methodology, initial interviews were audiotaped, and follow-up interviews were held within 2 weeks to extend the story of experience created from the first interview. Narrative plotlines across the 11 stories were identified, and a composite story inclusive of all recommendations was developed by the authors. The research findings and composite narrative were used to inform the CPG Expert Panel in the development of new CPGs. Four recommended directions were identified from the narrative inquiry process and applied. First, terminology that caused stigma was a concern. This resulted in modified language ("injured persons") being adopted by the Expert Panel, and a new nomenclature categorizing layers of injury was identified. Second, participants valued being engaged as partners with health care practitioners. This resulted in inclusion of shared decision-making as a foundational recommendation connecting CPGs and care planning. Third, emotional distress was recognized as a factor in recovery. Therefore, the importance of early detection and the ongoing evaluation of risk factors for delayed recovery were included in all CPGs. Fourth, participants shared that they were unfamiliar with the health care system and insurance industry before their accident. Thus, repeatedly orienting injured persons to the system was advised. A narrative inquiry of 11 patients' experiences with traffic collision and their recommendations for clinical

  6. Discrepancies Between Laboratory Shock Experiments on Minerals and Natural Events

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    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

  7. Scaled Laboratory Collisionless Shock Experiments in the Large Plasma Device

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  8. Internal Gravity Waves: Generation and Breaking Mechanisms by Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    la Forgia, Giovanni; Adduce, Claudia; Falcini, Federico

    2016-04-01

    Internal gravity waves (IGWs), occurring within estuaries and the coastal oceans, are manifest as large amplitude undulations of the pycnocline. IGWs propagating horizontally in a two layer stratified fluid are studied. The breaking of an IGW of depression shoaling upon a uniformly sloping boundary is investigated experimentally. Breaking dynamics beneath the shoaling waves causes both mixing and wave-induced near-bottom vortices suspending and redistributing the bed material. Laboratory experiments are conducted in a Perspex tank through the standard lock-release method, following the technique described in Sutherland et al. (2013). Each experiment is analysed and the instantaneous pycnocline position is measured, in order to obtain both geometric and kinematic features of the IGW: amplitude, wavelength and celerity. IGWs main features depend on the geometrical parameters that define the initial experimental setting: the density difference between the layers, the total depth, the layers depth ratio, the aspect ratio, and the displacement between the pycnoclines. Relations between IGWs geometric and kinematic features and the initial setting parameters are analysed. The approach of the IGWs toward a uniform slope is investigated in the present experiments. Depending on wave and slope characteristics, different breaking and mixing processes are observed. Sediments are sprinkled on the slope to visualize boundary layer separation in order to analyze the suspension e redistribution mechanisms due to the wave breaking.

  9. Hypervelocity Impact Experiments in the Laboratory Relating to Lunar Astrobiology

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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.

  10. Laboratory experiment of seismic cycles using compliant viscoelastic materials

    NASA Astrophysics Data System (ADS)

    Yamaguchi, T.

    2016-12-01

    It is well known that surface asperities at fault interfaces play an essential role in stick-slip friction. There have been many laboratory experiments conducted using rocks and some analogue materials to understand the effects of asperities and the underlying mechanisms. Among such materials, soft polymer gels have great advantages of slowing down propagating rupture front speed as well as shear wave speed: it facilitates observation of the dynamic rupture behavior. However, most experiments were done with bimaterial interfaces (combination of soft and hard materials) and there are few experiments with an identical (gel on gel) setup. Furthermore, there have been also few studies mentioning the link between local asperity contact and macroscopic dynamic rupture behavior. In this talk, we report our experimental studies on stick-slip friction between gels having controlled artificial asperities. We show that, depending on number density and configuration randomness of the asperities, the rupture behavior greatly changes: when the asperities are located periodically with optimum number densities, fast rupture propagation occurs, while slow and heterogeneous slip behavior is observed for samples having randomly located asperities. We discuss the importance of low frequency (large wavelength) excitation of the normal displacement contributing to weakening the fault interface. We also discuss the observed regular to slow slip transition with a simple model.

  11. The Software Engineering Laboratory: An operational software experience factory

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  12. Laboratory simulations of the pyrolytic release experiments - An interim report

    NASA Technical Reports Server (NTRS)

    Hubbard, J. S.

    1979-01-01

    During its operation on Mars the pyrolytic release experiment (PR) detected the fixation of small amounts of CO2 and/or CO. Laboratory simulations of the experimental conditions were made in an attempt to substantiate the previous conclusion that these reactions were chemical rather than biological. After pretreatment and incubation under various conditions, pyrolytic analysis was used to indicate the extent of surface catalyzed conversion of (C-14)O2 or (C-14)O to (C-14)-organic compounds. This abiotic synthesis was detected in experiments with three iron oxides, viz. hematite, magnetite and maghemite. When the incubation atmosphere was supplemented with water vapor, the levels of synthesis were in a range comparable to that detected in the Viking PR tests. An abiotic synthesis was also detected in experiments with a mixture of clays and minerals (Mars analog soil) or with montmorillonite artificially enriched in iron. With either substratum the reaction appeared to be the result of a photocatalytic synthesis of (C-14)-organics from (C-14)O and surface hydroxyl groups. This process was not dependent on the presence of water vapor in the incubation atmosphere. Although a duplication of the Viking data has not been achieved, these findings support the abiotic interpretation of the PR results.

  13. Transverse dispersion: From laboratory experiments to field applications

    NASA Astrophysics Data System (ADS)

    Grathwohl, Peter; Rügner, Hermann

    2016-04-01

    Transverse dispersion is relevant for dilution of contaminant plumes in groundwater and in many cases controls the length of steady state plumes during natural attenuation. Also dissolution kinetics of NAPLs in porous media and mass transfer of vapor phase compounds across the capillary fringe (e.g. supply of oxygen) is limited by transverse dispersion. In bench scale laboratory experiments typically very small dispersion coefficients are observed. Transverse dispersivities determined in DNAPL pool dissolution experiments in coarse sands are less than 0.1 mm which agrees with results from lab experiments on dilution of tracers and transfer of oxygen across the capillary fringe. Such low dispersivities lead to long-term persistence of DNAPL pools of many decades to centuries which is confirmed e.g. for chlorinated solvents and coal tars by observations at contaminated sites. However, larger scale investigations, e.g. determination of the length of steady state plumes or reduction of mass fluxes of biodegradable compounds suggest that transverse dispersivities at field scale are up to 3 orders of magnitude higher (1 -10 cm). Reasons for this discrepancy are still unclear, but may be partly explained by processes enhancing transverse mixing such as flow focusing due to aquifer geometries or high permeability inclusions and helical groundwater flow induced by herringbone structures in sediments.

  14. Laboratory astrophysical collisionless shock experiments on Omega and NIF

    NASA Astrophysics Data System (ADS)

    Park, Hye-Sook; Ross, J. S.; Huntington, C. M.; Fiuza, F.; Ryutov, D.; Casey, D.; Drake, R. P.; Fiksel, G.; Froula, D.; Gregori, G.; Kugland, N. L.; Kuranz, C.; Levy, M. C.; Li, C. K.; Meinecke, J.; Morita, T.; Petrasso, R.; Plechaty, C.; Remington, B.; Sakawa, Y.; Spitkovsky, A.; Takabe, H.; Zylstra, A. B.

    2016-03-01

    We are performing scaled astrophysics experiments on Omega and on NIF. Laser driven counter-streaming interpenetrating supersonic plasma flows can be studied to understand astrophysical electromagnetic plasma phenomena in a controlled laboratory setting. In our Omega experiments, the counter-streaming flow plasma state is measured using Thomson scattering diagnostics, demonstrating the plasma flows are indeed super-sonic and in the collisionless regime. We observe a surprising additional electron and ion heating from ion drag force in the double flow experiments that are attributed to the ion drag force and electrostatic instabilities. [1] A proton probe is used to image the electric and magnetic fields. We observe unexpected large, stable and reproducible electromagnetic field structures that arise in the counter-streaming flows [2]. The Biermann battery magnetic field generated near the target plane, advected along the flows, and recompressed near the midplane explains the cause of such self-organizing field structures [3]. A D3He implosion proton probe image showed very clear filamentary structures; three-dimensional Particle-In-Cell simulations and simulated proton radiography images indicate that these filamentary structures are generated by Weibel instabilities and that the magnetization level (ratio of magnetic energy over kinetic energy in the system) is ∼0.01 [4]. These findings have very high astrophysical relevance and significant implications. We expect to observe true collisionless shock formation when we use >100 kJ laser energy on NIF.

  15. A Simple Laboratory Experiment to Measure e/k

    NASA Astrophysics Data System (ADS)

    Inman, Fred

    2005-01-01

    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 I 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-kΩ potentiometer, as shown in Fig. 1. If available, a variable dc power supply replacing the battery and potentiometer would be more convenient.

  16. Magnetic shielding of a laboratory Hall thruster. II. Experiments

    SciTech Connect

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

    2014-01-28

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

  17. The Nature of Laboratory Learning Experiences in Secondary Science Online

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

    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.

  18. Dimensioning IRGA gas sampling systems: laboratory and field experiments

    NASA Astrophysics Data System (ADS)

    Aubinet, Marc; Joly, Lilian; Loustau, Denis; De Ligne, Anne; Chopin, Henri; Cousin, Julien; Chauvin, Nicolas; Decarpenterie, Thomas; Gross, Patrick

    2016-03-01

    Both laboratory and field experiments were carried out in order to define suitable configuration ranges for the gas sampling systems (GSSs) of infrared gas analyzers (IRGAs) used in eddy covariance measurements.

    In the laboratory, an original dynamic calibration bench was developed in order to test the frequency attenuation and pressure drop generated by filters. In the field, three IRGAs of the same type equipped with different filters or different rain caps were installed and run and the real frequency response of the complete setup was tested. The main results are as follows. - Filters may have a strong impact on the pressure drop in the GSS and this impact increases with flow rate. - Conversely, no impact of the tested filters on cut-off frequency was found, GSSs with and without filters presenting similar cut-off frequencies. - The main limiting factor of cut-off frequency in the field was found to be the rain cap design. In addition, the impact of this design on pressure drop was also found to be noteworthy.

  19. Dimensioning IRGA gas sampling system : laboratory and field experiments

    NASA Astrophysics Data System (ADS)

    Aubinet, Marc; Joly, Lilian; Loustau, Denis; De Ligne, Anne; Chopin, Henri; Cousin, Julien; De Carpenterie, Thomas; Gross, Patrick; Chauvin, Nicolas

    2016-04-01

    Both laboratory and field experiments were carried out in order to define suitable configuration ranges for the gas sampling systems (GSS) of infrared gas analyzers (IRGA) used in eddy covariance measurements. In the laboratory, an original dynamic calibration bench was developed in order to test the frequency attenuation and pressure drop generated by filters. In the field, three IRGAs of the same type equipped with different filters or different rain caps were installed and run and the real frequency response of the complete set-up was tested. The main results are that: - Filters may have a strong impact on the pressure drop in the GSS and this impact increases with flow rate. - On the contrary, no impact of the tested filters on cut off frequency was found, GSS with and without filters presenting similar cut off frequencies. - The main limiting factor of cut off frequency in the field was found to be the rain cap design. In addition, the impact of this design on pressure drop was also found noteworthy.

  20. Unsteady magnetic reconnection in laboratory experiments with current sheets

    NASA Astrophysics Data System (ADS)

    Frank, Anna

    2009-11-01

    According to present notion, unsteady magnetic reconnection in current sheets (CS) is basic to dramatic natural phenomena: solar and stellar flares, substorms in the Earth and other planetary magnetospheres, as well as to disruptive instabilities in tokamak plasmas. We present a review of laboratory experiments studying evolution of CS formed in 3D and 2D magnetic configurations with an X line, in the CS-3D device. Usually CS exists during an extended period in a metastable stage, without essential changes of its structure and parameters. Under certain conditions this stage may be suddenly interrupted by unsteady phase of magnetic reconnection, which manifests itself in a rapid change of the magnetic field topology, current redistribution, excitation of pulsed electric fields, and other dynamic effects. The unsteady phase results in effective conversion of magnetic energy into the energy of plasma and accelerated particles, and may finally bring about the CS disruption. In the context of the solar flares, a metastable CS is associated with a pre-flare situation, while CS disruption -- with the flare itself. The physical mechanisms triggering the unsteady magnetic reconnection in the laboratory produced current sheets are discussed. Supported by the Russian Foundation for Basic Research (project # 09-02-00971).

  1. Slew maneuvers of Spacecraft Control Laboratory Experiment (SCOLE)

    NASA Technical Reports Server (NTRS)

    Kakad, Yogendra P.

    1992-01-01

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

  2. Seeded FEL Microbunching Experiments at the UCLA Neptune Laboratory

    SciTech Connect

    Tochitsky, S. Ya.; Musumeci, P.; Rosenzweig, J. B.; Joshi, C.; Gottschalk, S. C.

    2010-11-04

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

  3. Deformation Monitoring of Materials Under Stress in Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Skarlatos, D.; Yiatros, S.

    2016-06-01

    Photogrammetry is a valid alternative solution to linear variable differential transformer (LVDT) measurements in structural testing in laboratory conditions. Although the use of LVDTs boasts a high degree of accuracy, on the other hand it is limiting as it offers measurements between two points and it thus might be unable to capture localized deformations and strains over a bigger area of a structural specimen. In this aspect photogrammetry seems to offer certain advantages. Commercial solutions provide limited testing envelopes, while on the other hand, the wide range on new materials need more versatile techniques. Based on the need to develop an in-house photogrammetric toolbox to support several structural and material experiments in the department Advanced Pore Morphology (APM) aluminium foam specimens developed at Fraunhofer IFAM in Germany and cured at CUT, were tested under monotonic compressive load. Data acquisition, analysis and results, along with lessons learnt from the process are presented in this work.

  4. Laboratory experiment of the rock anelastic strain recovery compliances

    NASA Astrophysics Data System (ADS)

    Gao, Lu; Wang, Lianjie

    2012-09-01

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

  5. Experience of Implementing ISO 15189 Accreditation at a University Laboratory

    PubMed Central

    2015-01-01

    The present article summarizes the authors’ experience with the implementation of a quality management system based on ISO 17025 and ISO 15189 standards at university laboratories. The accreditation of the analytical procedures at the Universidad Mariano Gálvez represented a challenge due to the unique nature of an educational institution and the difference in nature to the standards implemented. Sample handling and care of the patient were combined to achieve an integrated management system. We explain the development of the management system, the obstacles and benefits of the system and concluding that it is possible to design a management system based on ISO 15189 for the university lab that allowed delivering results assuring technical competence to patient care and welfare. PMID:27683499

  6. Inverse Free Electron Laser Experiment at the Neptune Laboratory

    NASA Astrophysics Data System (ADS)

    Musumeci, P.; Pellegrini, C.; Rosenzweig, J. B.; Varfolomeev, A.; Tolmachev, S.; Yarovoi, T.

    2002-12-01

    We present an Inverse Free Electron Laser accelerator proposed for construction at the UCLA Neptune Laboratory. This experiment will use a 1 TW CO2 laser to accelerate through two strongly tapered undulators an electron beam from 16 MeV up to 55 MeV. The scheme proposed is the diffraction dominated IFEL interaction. The Raleigh range of the laser beam is about 2 cm, much shorter than the interaction length (the undulator length is 50 cm). In this regime adiabatic capture is possible in the first part of the undulator. In the focus region, we propose a solution to the problem of the dephasing between electrons and photons due to the Guoy phase shift. Ponderomotive effects and implications for tolerances are also studied.

  7. LABORATORY EXPERIMENTS TO SIMULATE CO2 OCEAN DISPOSAL

    SciTech Connect

    Stephen M. Masutani

    1999-12-31

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

  8. Experimenting in a constructivist high school physics laboratory

    NASA Astrophysics Data System (ADS)

    Roth, Wolff-Michael

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

  9. Rainfall estimation using moving cars as rain gauges - laboratory experiments

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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.

  10. Rainfall estimation using moving cars as rain gauges - laboratory experiments

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

  11. Central Exclusive Production in Proton-Proton Collisions with the STAR Experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Guryn, Włodek

    2016-07-01

    We shall describe the physics program with tagged forward protons, focusing on Central Exclusive Production in polarized proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC), with the STAR detector at √s = 200 GeV. Preliminary results in CEP of two oppositely charged pions and kaons produced in the processes pp → ppπ+π- and pp → ppK+K- shall be presented. Those Double Pomeron Exchange (DPE) processes, allow the final states to be dominated by gluonic exchanges. Silicon strip detectors placed in Roman Pots were used for measuring forward protons. The preliminary results are based on the measurement of the recoil system of charged particles in the STAR experiment's Time Projection Chamber (TPC). Ionization energy loss, dE/dx, of charged particles was used for particle identification (PID).

  12. Transformation of fault slip modes in laboratory experiments

    NASA Astrophysics Data System (ADS)

    Martynov, Vasilii; Alexey, Ostapchuk; Markov, Vadim

    2017-04-01

    Slip mode of crust fault can vary because of many reasons. It's well known that fault structure, material of fault gouge, pore fluid et al. in many ways determines slip modes from creep and slow slip events to mega-earthquakes [1-3]. Therefore, the possibility of fault slip transformation due to external action is urgent question. There is popular and developing approach of fluid injection into central part of fault. The phenomenon of earthquakes induced due to pumping of water was investigated on small and large scales [4, 5]. In this work the laboratory experiments were conducted to study the evolution of the experimental fault slip when changing the properties of the interstitial fluid. The scheme of experiments is the classical slider-model set-up, in which the block under the shear force slips along the interface. In our experiments the plexiglas block 8x8x3 cm3 in size was put on the plexiglas base. The contact of the blocks was filled with a thin layer (about 3 mm thick) of a granular material. The normal load varied from 31 to 156 kPa. The shear load was applied through a spring with stiffness 60 kN/m, and the rate of spring deformation was 20 or 5 mcm/s. Two parameters were recorded during experiments: the shear force acting on the upper block (with an accuracy of 1 N) and its displacement relatively the base (with an accuracy of 0.1 μm). The gouge was composed of quartz sand (97.5%) and clay (2.5%). As a moisturizer were used different fluids with viscosity varying from 1 to 103 mPa x s. Different slip modes were simulated during slider-experiments. In our experiments slip mode is the act of instability manifested in an increase of slip velocity and a drop of shear stress acting on a movable block. The amplitude of a shear stress drop and the peak velocity of the upper block were chosen as the characteristics of the slip mode. In the laboratory experiments, slip events of one type can be achieved either as regularly recurring (regular mode) or as random

  13. Boulder transport by tsunamis: A laboratory experiment on incipient motion

    NASA Astrophysics Data System (ADS)

    Bressan, Lidia; Antonini, Alessandro; Gaeta, Maria Gabriella; Guerrero, Massimo; Miani, Marco; Petruzzelli, Valentina; Samaras, Achilleas

    2015-04-01

    Coastal boulders transported inland by high-energy events, such as tsunamis or storms, have been found along several coastal areas worldwide. The importance of these deposits relies on their implications on coastal hazard assessment, since they contribute to the identification of past events and to the study of their magnitude and characteristics. However, the identification of the event responsible of the dislocation of the boulder (tsunami or storm) is not trivial given the complexities of the tsunami and storm phenomena, the coastal environment, the initial boulder conditions, the uncertainties of the problem, etc. The hydrodynamics methods usually adopted are 1) the use of simple hydrodynamics formulae to estimate the minimum flow velocity and height required to move a boulder, and 2) numerical simulations that model the boulder transport together with the specific tsunami (or storm) event. The main shortcomings of the first method are the simplifications adopted, while the second approach implies the simulation of the transport event, which might not be practical because of the amount of uncertainties involved. To contribute to this study field, a laboratory experiment on the flow conditions for boulder transport was carried out at the Hydraulic Engineering Laboratory (LIDR) of the University of Bologna, Italy, in a 11 m long and 0.5 m wide flume. The main objective of this experiment is to provide experimental data for the conditions of the incipient motion for boulders, i.e. to relate the threshold flow velocity and depth for transport with the characteristics of the boulders, i.e. weight and geometry. The experimental channel is divided in three parts: on one end of the channel, a water tank is closed by a gate, followed by a central flat bed and a 1:10 slope, where the boulder is located. A bore, generated by quickly opening the gate (simulating a dam-break), flows in the channel, climbs up the slope and hits the boulder. The impact of the flow on the

  14. Cyclic deformations in the Opalinus clay: a laboratory experiment

    NASA Astrophysics Data System (ADS)

    Huber, Emanuel; Huggenberger, Peter; Möri, Andreas; Meier, Edi

    2015-04-01

    The influence of tunnel climate on deformation cycles of joint openings and closings is often observed immediately after excavation. At the EZ-B niche in the Mt. Terri rock laboratory (Switzerland), a cyclic deformation of the shaly Opalinus clay has been monitored for several years. The deformation cycles of the joints parallel to the clay bedding planes correlate with seasonal variations in relative humidity of the air in the niche. In winter, when the relative humidity is the lowest (down to 65%), the joints open as the clay volume decreases, whereas they tend to close in the summer when the relative humidity reaches up to 100%. Furthermore, in situ measurements have shown the trend of an increasingly smaller aperture of joints with time. A laboratory experiment was carried out to reproduce the observed cyclic deformation in a climate chamber using a core sample of Opalinus clay. The main goal of the experiment was to investigate the influence of the relative humidity on the deformation of the Opalinus clay while excluding the in situ effects (e.g. confining stress). The core sample of Opalinus clay was put into a closed ended PVC tube and the space between the sample and the tube was filled with resin. Then, the sample (size: 28 cm × 14 cm × 6.5 cm) was cut in half lengthways and the open end was cut, so that the half-core sample could move in one direction. The mounted sample was exposed to wetting and drying cycles in a climate chamber. Air temperature, air humidity and sample weight were continuously recorded. Photographs taken at regular time intervals by a webcam allowed the formation/deformation of cracks on the surface of the sample to be monitored. A crackmeter consisting of a double-plate capacitor attached to the core sample was developed to measure the dynamics of the crack opening and closing. Preliminary results show that: - Deformation movements during different climate cycles can be visualized with the webcam - The crackmeter signal gives a

  15. Atomic collision experiments utilizing low-velocity, highly-charged ion beams

    SciTech Connect

    Johnson, B.M.; Jones, K.W.; Meron, M.

    1982-01-01

    Intense beams of highly-stripped ions are now routinely produced at low velocities using the Brookhaven dual MP-tandens in a unique four-stage accel/decel mode. This mode of operation combines three stages of acceleration, stripping at high energy, and one stage of deceleration to near-zero velocity. To date, experiments have used 10-100 nA beams of bare and few-electron heavy ions at energies as low as 0.2 MeV/amu, and upgrades of the facility should push the lower limit below 0.1 MeV/amu. Recent experiments, such as measurements of charge transfer and x-ray production for S/sup 6-16+/ on He and Ar at 6 to 20 MeV and P(b) measurements for MO x-rays produced in Cl/sup 16 +/ + Ar collisions at 20, 10, and 5 MeV have demonstrated the usefulness of highly-stripped, low-velocity projectiles. These experiments and a few possibilities for future experiments are discussed.

  16. Recording the PHILAE Touchdown using CASSE: Laboratory Experiments

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  17. Photocatalytic Hydrogen Production by Direct Sunlight: A Laboratory Experiment

    NASA Astrophysics Data System (ADS)

    Koca, Atif; Sahin, Musa

    2003-11-01

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

  18. Laboratory Experiments Modelling Sediment Transport by River Plumes

    NASA Astrophysics Data System (ADS)

    Sutherland, Bruce; Gingras, Murray; Knudson, Calla; Steverango, Luke; Surma, Chris

    2016-11-01

    Through lock-release laboratory experiments, the transport of particles by hypopycnal (surface) currents is examined as they flow into a uniform-density and a two-layer ambient fluid. In most cases the tank is tilted so that the current flows over a slope representing an idealization of a sediment-bearing river flowing into the ocean and passing over the continental shelf. When passing into a uniform-density ambient, the hypopycnal current slows and stops as particles rain out, carrying some of the light interstitial fluid with them. Rather than settling on the bottom, in many cases the descending particles accumulate to form a hyperpycnal (turbidity) current that flows downslope. This current then slows and stops as particles both rain out to the bottom and also rise again to the surface, carried upward by the light interstitial fluid. For a hypopycnal current flowing into a two-layer fluid, the current slows as particles rain out and accumulate at the interface of the two-layer ambient. Eventually these particles penetrate through the interface and settle to the bottom with no apparent formation of a hyperpycnal current. Analyses are performed to characterize the speed of the currents and stopping distances as they depend upon experiment parameters. Natural Sciences and Engineering Research Council.

  19. Design of laboratory experiments to study photoionization fronts

    NASA Astrophysics Data System (ADS)

    Drake, R. P.; Hazak, G.; Keiter, P. A.; Davis, J. S.; Patterson, C. R.; Frank, A.; Blackman, E.; Busquet, M.

    2016-10-01

    This paper analyzes the requirements of a photoionization-front experiment that could be driven in the laboratory, using thermal sources to produce the necessary flux of ionizing photons. It reports several associated conclusions. Such experiments will need to employ the largest available facilities, capable of delivering many kJ to MJ of energy to an x-ray source. They will use this source to irradiate a volume of neutral gas, likely of N, on a scale of a few mm to a few cm, increasing with source energy. For a gas pressure of several to ten atmospheres at room temperature, and a source temperature near 100 eV, one will be able to drive a photoionization front through a system of tens to hundreds of photon mean free paths. The front should make the familiar transition from the so-called R-Type to D-Type as the radiation flux diminishes with distance. The N is likely to reach the He-like state. Preheating from the energetic photons appears unlikely to become large enough to alter the essential dynamics of the front beyond some layer near the surface. For well-chosen experimental conditions, competing energy transport mechanisms are small. Supported by the U.S. DOE by NNSA Grants DE-NA0002956 (SSAA) and DE-NA0002719 (NLUF), by LLE, and by LLNL.

  20. Laboratory Experiment of Saltwater Intrusion into Freshwater Aquifer

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    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.

  1. Dilepton and φ meson production in elementary and nuclear collisions at the NICA fixed-target experiment

    NASA Astrophysics Data System (ADS)

    Wolf, György; Zétényi, Miklós

    2016-08-01

    We argue that the NICA fixed-target experiment will be able to provide very important new experimental data on dilepton and φ meson production in the basically undiscovered energy domain between the SIS and SPS energies. Experimental information about elementary cross sections in this energy region is an essential ingredient of models of nuclear collisions in the same energy range.

  2. Estimating sphagnum peat hydraulic properties from laboratory evaporation experiments

    NASA Astrophysics Data System (ADS)

    Weber, Tobias K. D.; Durner, Wolfgang

    2013-04-01

    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.

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

    ERIC Educational Resources Information Center

    Hesser, Tiffany L.; Schwartz, Pauline M.

    2013-01-01

    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…

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

    ERIC Educational Resources Information Center

    Hesser, Tiffany L.; Schwartz, Pauline M.

    2013-01-01

    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…

  5. Laboratory Experiments On Continually Forced 2d Turbulence

    NASA Astrophysics Data System (ADS)

    Wells, M. G.; Clercx, H. J. H.; Van Heijst, G. J. F.

    There has been much recent interest in the advection of tracers by 2D turbulence in geophysical flows. While there is a large body of literature on decaying 2D turbulence or forced 2D turbulence in unbounded domains, there have been very few studies of forced turbulence in bounded domains. In this study we present new experimental results from a continuously forced quasi 2D turbulent field. The experiments are performed in a square Perspex tank filled with water. The flow is made quasi 2D by a steady background rotation. The rotation rate of the tank has a small (<8 %) sinusoidal perturbation which leads to the periodic formation of eddies in the corners of the tank. When the oscillation period of the perturbation is greater than an eddy roll-up time-scale, dipole structures are observed to form. The dipoles can migrate away from the walls, and the interior of the tank is continually filled with vortexs. From experimental visualizations the length scale of the vortexs appears to be largely controlled by the initial formation mechanism and large scale structures are not observed to form at large times. Thus the experiments provide a simple way of cre- ating a continuously forced 2D turbulent field. The resulting structures are in contrast with most previous laboratory experiments on 2D turbulence which have investigated decaying turbulence and have observed the formations of large scale structure. In these experiments, decaying turbulence had been produced by a variety of methods such as the decaying turbulence in the wake of a comb of rods (Massen et al 1999), organiza- tion of vortices in thin conducting liquids (Cardoso et al 1994) or in rotating systems where there are sudden changes in angular rotation rate (Konijnenberg et al 1998). Results of dye visualizations, particle tracking experiments and a direct numerical simulation will be presented and discussed in terms of their oceanographic application. Bibliography Cardoso,O. Marteau, D. &Tabeling, P

  6. Collisions of Ir oxide nanoparticles with carbon nanopipettes: Experiments with one nanoparticle

    DOE PAGES

    Zhou, Min; Yu, Yun; Hu, Keke; ...

    2017-02-03

    Investigating the collisions of individual metal nanoparticles (NPs) with electrodes can provide new insights into their electrocatalytic behavior, mass transport, and interactions with surfaces. Here we report a new experimental setup for studying NP collisions based on the use of carbon nanopipettes to enable monitoring multiple collision events involving the same NP captured inside the pipet cavity. A patch clamp amplifier capable of measuring pA-range currents on the microsecond time scale with a very low noise and stable background was used to record the collision transients. The analysis of current transients produced by oxidation of hydrogen peroxide at one IrOxmore » NP provided information about the origins of deactivation of catalytic NPs and the effects of various experimental conditions on the collision dynamics. Lastly, high-resolution TEM of carbon pipettes was used to attain better understanding of the NP capture and collisions.« less

  7. Experiments with an ion-neutral hybrid trap: cold charge-exchange collisions

    NASA Astrophysics Data System (ADS)

    Smith, W. W.; Goodman, D. S.; Sivarajah, I.; Wells, J. E.; Banerjee, S.; Côté, R.; Michels, H. H.; Mongtomery, J. A.; Narducci, F. A.

    2014-01-01

    Due to their large trap depths (˜1 eV or 10,000 K), versatility, and ease of construction, Paul traps have important uses in high-resolution spectroscopy, plasma physics, and precision measurements of fundamental constants. An ion-neutral hybrid trap consisting of two separate but spatially concentric traps [a magneto-optic trap (MOT) for the neutral species and a mass-selective linear Paul trap for the ionic species] is an ideal apparatus for sympathetic cooling. However, over the past few years, hybrid traps have proven most useful in measuring elastic and charge-exchange rate constants of ion-neutral collisions over a wide temperature range from kilo-Kelvin to nano-Kelvin. We report some initially surprising results from a hybrid trap system in our laboratory where we have loaded the Paul trap with Ca+ ions in the presence of a Na MOT (localized dense gas of cold Na atoms). We find a strong loss of Ca+ ions with MOT exposure, attributed to an exothermic, non-resonant ion-neutral charge-exchange process with an activation barrier, which leads to the formation of Na+ ions. We propose a detailed mechanism for this process. We obtain an estimated measure of the rate constant for this charge exchange of ˜2 × 10-11 cm3/s, much less than the Langevin rate, which suggests that the Langevin assumption of unit efficiency in the reaction region is not correct in this case.

  8. Previous Driving Experience, but Not Vision, Is Associated With Motor Vehicle Collision Rate in Bioptic Drivers

    PubMed Central

    Dougherty, Bradley E.; Flom, Roanne E.; Bullimore, Mark A.; Raasch, Thomas W.

    2015-01-01

    Purpose Bioptic telescopic spectacles (BTS) consist of a small telescope (or telescopes) mounted high in a pair of spectacle lenses. More than 40 states allow for some form of bioptic driving licensure for people with decreased central vision. The purpose of this study was to determine significant associations among previous driving experience, vision, and motor vehicle collisions (MVCs) for bioptic drivers in Ohio. Methods We conducted a retrospective study of patients who received a vision examination and subsequently obtained bioptic licensure. We obtained driving records from the Ohio Bureau of Motor Vehicles in order to determine MVC involvement. Relationships among vision measures, age, sex, previous experience, and MVCs were investigated using time-to-event analysis and the Cox proportional hazards regression model. Results We identified 237 bioptic drivers (65% male). Age at initial exam ranged from 16 to 81 years, and mean visual acuity was approximately 20/120. The number of MVCs per driver ranged from 0 to 11, with 124 (52%) drivers having had at least one MVC. Visual acuity and contrast sensitivity were not significant predictors of MVC. Drivers without previous driving experience were significantly more likely to have been involved in an MVC (P < 0.001), and this association remained significant after adjusting for age and sex (P = 0.01). The rate of MVC per year decreased steadily over a 10-year period for drivers without previous experience. Conclusions Previous nonbioptic driving experience, but not visual acuity or contrast sensitivity, was associated with yearly MVC rate in bioptic drivers. PMID:26436885

  9. Measuring dynamical K/π and p/π fluctuations in AuAu collisions from the STAR experiment

    NASA Astrophysics Data System (ADS)

    Tarnowsky, T.

    2012-05-01

    Results from new measurements of dynamical K/π and p/π ratio fluctuations are presented. Dynamical fluctuations in global conserved quantities such as baryon number, strangeness, or charge may be observed near a QCD critical point. The STAR experiment has previously acquired data in AuAu collisions at the energies √{s_{NN} } = 200, 130, 62.4, and 19.6 GeV and CuCu collisions at √{s_{NN} } = 200, 62.4, and 22.4 GeV. The commencing of a QCD critical point search at RHIC has extended the reach of possible measurements of dynamical K/π and p/π ratio fluctuations from AuAu collisions to lower energies. New results are compared to previous measurements and to theoretical predictions from the UrQMD model.

  10. New Laboratory-Based Satellite Impact Experiments for Breakup Fragment Characterization

    NASA Technical Reports Server (NTRS)

    Liou, J.-C.; Fitz-Coy, N.; Dikova, R.; Wilson, M.; Huynh, T.; Sorge, M.; Sheaffer, P.; Opiela, J.; Cowardin, H.; Krisko, P.; hide

    2014-01-01

    A consortium consisting of the NASA Orbital Debris Program Office, U.S. Air Force's Space and Missile Systems Center, the Aerospace Corporation, and University of Florida is planning a series of hypervelocity impact experiments on mockup targets at the U.S. Air Force's Arnold Engineering Development Complex (AEDC) in early 2014. The target for the first experiment resembles a rocket upper stage whereas the target for the second experiment represents a typical 60-cm/50-kg class payload that incorporates modern spacecraft materials and components as well as exterior wrap of multi-layer insulation and three solar panels. The projectile is designed with the maximum mass that AEDC's Range G two-stage light gas gun can accelerate to an impact speed of 7 km/sec. The impact energy is expected to be close to 15 MJ to ensure catastrophic destruction of the target after the impact. Low density foam panels are installed inside the target chamber to slow down and soft-catch the fragments for post-impact processing. Diagnostic instruments, such as x-ray and high speed optical cameras, will also be used to record the breakup process. The main goal of this "DebriSat" project is to characterize the physical properties, including size, mass, shape, and density distributions, of orbital debris that would be generated by a hypervelocity collision involving an upper stage or a modern satellite in the low Earth orbit environment. In addition, representative fragments will be selected for laboratory optical and radar measurements to allow for better interpretation of data obtained by telescope and radar observations. This paper will provide a preliminary report of the impact results and the plans to process, measure, and analyze the fragments.

  11. New Laboratory-Based Satellite Impact Experiments for Breakup Fragment Characterization

    NASA Astrophysics Data System (ADS)

    Liou, J.-C.

    A consortium consisting of the NASA Orbital Debris Program Office, U.S. Air Force’s Space and Missile Systems Center, The Aerospace Corporation, and University of Florida is planning a series of hypervelocity impact experiments on mockup targets at the U.S. Air Force’s Arnold Engineering Development Complex (AEDC) in early 2014. The target for the first experiment resembles a rocket upper stage whereas the target for the second experiment represents a typical 60-cm/50-kg class payload that incorporates modern spacecraft materials and components as well as exterior wrap of multi-layer insulation and three solar panels. The projectile is designed with the maximum mass that AEDC’s Range G two-stage light gas gun can accelerate to an impact speed of 7 km/sec. The impact energy is expected to be close to 15 MJ to ensure catastrophic destruction of the target after the impact. Low density foam panels are installed inside the target chamber to slow down and soft-catch the fragments for post-impact processing. Diagnostic instruments, such as x-ray and high speed optical cameras, will also be used to record the breakup process. The main goal of this “DebriSat” project is to characterize the physical properties, including size, mass, shape, and density distributions, of orbital debris that would be generated by a hypervelocity collision involving an upper stage or a modern satellite in the low Earth orbit environment. In addition, representative fragments will be selected for laboratory optical and radar measurements to allow for better interpretation of data obtained by telescope and radar observations. This paper will provide a preliminary report of the impact results and the plans to process, measure, and analyze the fragments.

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

    ERIC Educational Resources Information Center

    Pierce, J. T.; And Others

    1984-01-01

    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)

  13. Emulating JWST Exoplanet Transit Observations in a Testbed laboratory experiment

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    The transit technique is used for the detection and characterization of exoplanets. The combination of transit and radial velocity (RV) measurements gives information about a planet's radius and mass, respectively, leading to an estimate of the planet's density (Borucki et al. 2011) and therefore to its composition and evolutionary history. Transit spectroscopy can provide information on atmospheric composition and structure (Fortney et al. 2013). Spectroscopic observations of individual planets have revealed atomic and molecular species such as H2O, CO2 and CH4 in atmospheres of planets orbiting bright stars, e.g. Deming et al. (2013). The transit observations require extremely precise photometry. For instance, Jupiter transit results to a 1% brightness decrease of a solar type star while the Earth causes only a 0.0084% decrease (84 ppm). Spectroscopic measurements require still greater precision <30ppm. The Precision Projector Laboratory (PPL) is a collaboration between the Jet Propulsion Laboratory (JPL) and California Institute of Technology (Caltech) to characterize and validate detectors through emulation of science images. At PPL we have developed a testbed to project simulated spectra and other images onto a HgCdTe array in order to assess precision photometry for transits, weak lensing etc. for Explorer concepts like JWST, WFIRST, EUCLID. In our controlled laboratory experiment, the goal is to demonstrate ability to extract weak transit spectra as expected for NIRCam, NIRIS and NIRSpec. Two lamps of variable intensity, along with spectral line and photometric simulation masks emulate the signals from a star-only, from a planet-only and finally, from a combination of a planet + star. Three masks have been used to simulate spectra in monochromatic light. These masks, which are fabricated at JPL, have a length of 1000 pixels and widths of 2 pixels, 10 pixels and 1 pixel to correspond respectively to the noted above JWST instruments. From many-hour long

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  15. Joint Langley Research Center/Jet Propulsion Laboratory CSI experiment

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  16. Laboratory experiments for estimating chemical osmotic parameters of mudstones

    NASA Astrophysics Data System (ADS)

    Miyoshi, S.; Tokunaga, T.; Mogi, K.; Ito, K.; Takeda, M.

    2010-12-01

    Recent studies have quantitatively shown that mudstone can act as semi-permeable membrane and can generate abnormally high pore pressure in sedimentary basins. Reflection coefficient is one of the important properties that affect the chemical osmotic behavior of mudstones. However, not many quantitative studies on the reflection coefficient of mudstones have been done. We have developed a laboratory apparatus to observe chemical osmotic behavior, and a numerical simulation technique to estimate the reflection coefficient and other relating properties of mudstones. A core sample of siliceous mudstone obtained from the drilled core at Horonobe, Japan, was set into the apparatus and was saturated by 0.1mol/L sodium chloride solution. Then, the up-side reservoir was replaced with 0.05mol/L sodium chloride solution, and temporal changes of both pressure and concentration of the solution in both up-side and bottom-side reservoirs were measured. Using the data obtained from the experiment, we estimated the reflection coefficient, effective diffusion coefficient, hydraulic conductivity, and specific storage of the sample by fitting the numerical simulation results with the observed ones. A preliminary numerical simulation of groundwater flow and solute migration was conducted in the area where the core sample was obtained, using the reflection coefficient and other properties obtained from this study. The result suggested that the abnormal pore pressure observed in the region can be explained by the chemical osmosis.

  17. Cometary Materials Originating from Interstellar Ices: Clues from Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Fresneau, A.; Abou Mrad, N.; d’Hendecourt, L. LS; Duvernay, F.; Flandinet, L.; Orthous-Daunay, F.-R.; Vuitton, V.; Thissen, R.; Chiavassa, T.; Danger, G.

    2017-03-01

    We use laboratory experiments to derive information on the chemistry occurring during the evolution of astrophysical ices from dense molecular clouds to interplanetary objects. Through a new strategy that consists of coupling very high resolution mass spectrometry and infrared spectroscopy (FT-IR), we investigate the molecular content of the organic residues synthesized from different initial ice compositions. We also obtain information on the evolution of the soluble part of the residues after their over-irradiation. The results give insight into the role of water ice as a trapping and diluting agent during the chemical evolution. They also give information about the importance of the amount of ammonia in such ices, particularly regarding its competition with the carbon chemistry. All of these results allow us to build a first mapping of the evolution of soluble organic matter based on its chemical and physical history. Furthermore, our results suggest that interstellar ices should lead to organic materials enriched in heteroatoms that present similarities with cometary materials but strongly differ from meteoritic organic material, especially in their C/N ratios.

  18. Control of Spacecraft Control Laboratory Experiment (SCOLE) slew maneuvers

    NASA Technical Reports Server (NTRS)

    Kakad, Y. P.

    1987-01-01

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

  19. Laboratory Experiments for Seawater Intrusion into Freshwater Aquifer with Heterogeneity

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

    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.

  20. Dynamics of spacecraft control laboratory experiment (SCOLE) slew maneuvers

    NASA Technical Reports Server (NTRS)

    Kakad, Y. P.

    1987-01-01

    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 about any given axis. The set of dynamical equations incorporate rigid-body slew maneuver and three-dimensional vibrations of the complete assembly comprising the rigid shuttle, the flexible beam, and the reflector with an offset mass. The analysis also includes kinematic nonlinearities of the entire assembly during the maneuver and the dynamics of the interaction between the rigid shuttle and the flexible appendage. The final set of dynamical equations obtained for slewing maneuvers is highly nonlinear and coupled in terms of the flexible modes and the rigid-body modes. The equations are further simplified and evaluated numerically to include the first ten flexible modes and the SCOLE data to yield a model for designing control systems to perform slew maneuvers.

  1. The digital computer as a metaphor for the perfect laboratory experiment: Loophole-free Bell experiments

    NASA Astrophysics Data System (ADS)

    De Raedt, Hans; Michielsen, Kristel; Hess, Karl

    2016-12-01

    Using Einstein-Podolsky-Rosen-Bohm experiments as an example, we demonstrate that the combination of a digital computer and algorithms, as a metaphor for a perfect laboratory experiment, provides solutions to problems of the foundations of physics. Employing discrete-event simulation, we present a counterexample to John Bell's remarkable "proof" that any theory of physics, which is both Einstein-local and "realistic" (counterfactually definite), results in a strong upper bound to the correlations that are being measured in Einstein-Podolsky-Rosen-Bohm experiments. Our counterexample, which is free of the so-called detection-, coincidence-, memory-, and contextuality loophole, violates this upper bound and fully agrees with the predictions of quantum theory for Einstein-Podolsky-Rosen-Bohm experiments.

  2. Lava-substrate heat transfer: Laboratory experiments and thermodynamic modeling

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    We have performed laboratory experiments and numerical modeling to investigate the heat transfer from a lava flow into various substrate materials, focusing on the effects of the differing thermophysical properties of substrate materials. Initial motivation for this project developed from the desire to understand the loss of solar wind volatiles embedded in lunar regolith deposits that were subsequently covered by a lava flow. The Moon lacks a significant atmosphere and magnetosphere, leaving the surface regolith exposed to bombardment by solar flare and solar wind particles, and by the cosmogenic products of galactic cosmic rays. Preservation of particle-rich regolith deposits may have occurred by the emplacement of an active lava flow on top of the regolith layer, provided the embedded particles survive heating by the lava. During future expeditions to the lunar surface, ancient regolith deposits could be sampled through surface drilling to extract the extra-lunar particles, revealing a history of the solar activity and galactic events not available on the Earth. This project also has important implications for terrestrial lava flows, particularly in the prediction of lava flow hazards. Lava erupted on Earth may be emplaced on various substrates, including solid lava rock, volcanic tephra, sands, soils, etc. The composition, grain size, consolidation, moisture content, etc. of these materials will vary greatly and have different effects on the cooling of the flow. Accounting for specific properties of the substrate could be an important improvement in lava flow models We have performed laboratory experiments in collaboration with the Department of Art and Art History at the University of Hawaii at Manoa in which ~5-6 kg of basalt, collected at Kilauea Volcano, Hawaii, is melted to ~1200 °C. The lava is poured into a device constructed of calcium silicate sheeting that has been filled with a solid or particulate substrate material and embedded with thermocouples

  3. Laboratory Experiments to Stimulate CO(2) Ocean Disposal

    SciTech Connect

    Masutani, S.M.

    1997-03-12

    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

  4. Effects of experience and electronic stability control on low friction collision avoidance in a truck driving simulator.

    PubMed

    Markkula, Gustav; Benderius, Ola; Wolff, Krister; Wahde, Mattias

    2013-01-01

    Two experiments were carried out in a moving-base simulator, in which truck drivers of varying experience levels encountered a rear-end collision scenario on a low-friction road surface, with and without an electronic stability control (ESC) system. In the first experiment, the drivers experienced one instance of the rear-end scenario unexpectedly, and then several instances of a version of the scenario adapted for repeated collision avoidance. In the second experiment, the unexpected rear-end scenario concluded a stretch of driving otherwise unrelated to the study presented here. Across both experiments, novice drivers were found to collide more often than experienced drivers in the unexpected scenario. This result was found to be attributable mainly to longer steering reaction times of the novice drivers, possibly caused by lower expectancy for steering avoidance. The paradigm for repeated collision avoidance was able to reproduce the type of steering avoidance situation for which critical losses of control were observed in the unexpected scenario and, here, ESC was found to reliably reduce skidding and control loss. However, it remains unclear to what extent the results regarding ESC benefits in repeated avoidance are generalisable to unexpected situations. The approach of collecting data by appending one unexpected scenario to the end of an otherwise unrelated experiment was found useful, albeit with some caveats.

  5. Near surface geophysical techniques on subsoil contamination: laboratory experiments

    NASA Astrophysics Data System (ADS)

    Capozzoli, Luigi; Giampaolo, Valeria; Rizzo, Enzo

    2016-04-01

    Hydrocarbons contamination of soil and groundwater has become a serious environmental problem, because of the increasing number of accidental spills caused by human activities. The starting point of any studies is the reconstruction of the conceptual site model. To make valid predictions about the flow pathways following by hydrocarbons compound is necessary to make a correct reconstruction of their characteristics and the environment in which they move. Near-surface geophysical methods, based on the study of electrical and electromagnetic properties, are proved to be very useful in mapping spatial distribution of the organic contaminants in the subsurface. It is well known, in fact, that electrical properties of the porous media are significantly influenced by hydrocarbons because, when contaminants enter the rock matrix, surface reaction occur between the contaminant and the soil grain surface. The main aim of this work is to investigate the capability of near-surface geophysical methods in mapping and monitoring spatial distribution of contaminants in a controlled setting. A laboratory experiment has been performed at the Hydrogeosite Laboratory of CNR-IMAA (Marsico Nuovo, PZ) where a box-sand has been contaminated by diesel. The used contaminant is a LNAPL, added to the sand through a drilled pipe. Contaminant behaviour and its migration paths have been monitored for one year by Electrical Resistivity measurements. In details, a Cross Borehole Electrical Resistivity Tomography techniques were used to characterize the contamination dynamics after a controlled hydrocarbon spillage occurring in the vadose zone. The approach with cross-borehole resistivity imaging provide a great advantage compared to more conventional surface electrical resistivity tomography, due to the high resolution at high depth (obviously depending on the depth of the well instrumented for the acquisition). This method has been shown to provide good information on the distribution of

  6. Lab-scale ash production by abrasion and collision experiments of porous volcanic samples

    NASA Astrophysics Data System (ADS)

    Mueller, Sebastian B.; Lane, Steve J.; Kueppers, Ulrich

    2014-05-01

    In the course of explosive eruptions, magma is fragmented into smaller pieces by a plethora of processes before deposition. Volcanic ash, all fragments smaller than 2 mm, may have imminent and near-volcano effects but may also cause various problems over long duration and/or far away from the source. In an attempt to quantify the efficiency of ash generation, various experimental setups were applied on pumice and scoria samples. We used samples collected on Tenerife (Canary Islands, Spain), Sicily and Lipari Islands (both Italy) for experiments that generated shear or normal stress fields or combinations of these within the rock samples. Experiments were designed to overcome low yield strengths of samples and produce ash, with this study having particular interest in the < 355 µm fraction. By abrasion and collision experiments, the processes that are likely to happen within volcanic conduits, plumes or pyroclastic density currents (PDCs) were simulated. An understanding of these secondary fragmentation processes is crucial as they are capable of producing very fine ash, with size ranges from a few microns to few millimetres. These particles are known to remain in the atmosphere for several days and travel large distances (~ 100s of km). This poses threats to the aviation industry and human health. From the experiments we establish that abrasion setups produced the finest material and up to 50% of the generated ash was smaller than 10 µm. In comparison, the drop experiments that applied mainly normal stress fields produced coarser grain sizes. Results were compared to grain size distributions described in literature for natural fall and PDC deposits and good correlation was found. Energies involved in drop experiments were calculated and showed an exponential correlation with ash production rate. Projecting these results into the actual volcanic environment, highest amounts of ash are produced in most energetic and turbulent areas, which are proximal to the vent

  7. Sampling Participants’ Experience in Laboratory Experiments: Complementary Challenges for More Complete Data Collection

    PubMed Central

    McAuliffe, Alan; McGann, Marek

    2016-01-01

    Speelman and McGann’s (2013) examination of the uncritical way in which the mean is often used in psychological research raises questions both about the average’s reliability and its validity. In the present paper, we argue that interrogating the validity of the mean involves, amongst other things, a better understanding of the person’s experiences, the meaning of their actions, at the time that the behavior of interest is carried out. Recently emerging approaches within Psychology and Cognitive Science have argued strongly that experience should play a more central role in our examination of behavioral data, but the relationship between experience and behavior remains very poorly understood. We outline some of the history of the science on this fraught relationship, as well as arguing that contemporary methods for studying experience fall into one of two categories. “Wide” approaches tend to incorporate naturalistic behavior settings, but sacrifice accuracy and reliability in behavioral measurement. “Narrow” approaches maintain controlled measurement of behavior, but involve too specific a sampling of experience, which obscures crucial temporal characteristics. We therefore argue for a novel, mid-range sampling technique, that extends Hurlburt’s descriptive experience sampling, and adapts it for the controlled setting of the laboratory. This controlled descriptive experience sampling may be an appropriate tool to help calibrate both the mean and the meaning of an experimental situation with one another. PMID:27242588

  8. Sampling Participants' Experience in Laboratory Experiments: Complementary Challenges for More Complete Data Collection.

    PubMed

    McAuliffe, Alan; McGann, Marek

    2016-01-01

    Speelman and McGann's (2013) examination of the uncritical way in which the mean is often used in psychological research raises questions both about the average's reliability and its validity. In the present paper, we argue that interrogating the validity of the mean involves, amongst other things, a better understanding of the person's experiences, the meaning of their actions, at the time that the behavior of interest is carried out. Recently emerging approaches within Psychology and Cognitive Science have argued strongly that experience should play a more central role in our examination of behavioral data, but the relationship between experience and behavior remains very poorly understood. We outline some of the history of the science on this fraught relationship, as well as arguing that contemporary methods for studying experience fall into one of two categories. "Wide" approaches tend to incorporate naturalistic behavior settings, but sacrifice accuracy and reliability in behavioral measurement. "Narrow" approaches maintain controlled measurement of behavior, but involve too specific a sampling of experience, which obscures crucial temporal characteristics. We therefore argue for a novel, mid-range sampling technique, that extends Hurlburt's descriptive experience sampling, and adapts it for the controlled setting of the laboratory. This controlled descriptive experience sampling may be an appropriate tool to help calibrate both the mean and the meaning of an experimental situation with one another.

  9. Explosive Pulsed Power Experiments At The Phillips Laboratory

    DTIC Science & Technology

    1997-06-01

    Weapons and Survivability Directorate Phillips Laboratory Kirtland AFB, NM 87117 J. Graham, W. Sornrnars Albuquerque Division Maxwell Technologies... Phillips Laboratory Kirtland AFB, NM 87117 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10...pulse shaping/impedance matching systems are discussed. Introduction Air Force missions utilizing pulsed power technology increasingly require the

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

    ERIC Educational Resources Information Center

    Elkins, Kelly M.

    2011-01-01

    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…

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

    ERIC Educational Resources Information Center

    Elkins, Kelly M.

    2011-01-01

    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…

  12. Hands-on laboratory Experience in Teaching-Learning Physiology.

    ERIC Educational Resources Information Center

    Randall, Walter C.; Burkholder, Timothy

    1990-01-01

    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…

  13. Simulation of astrophysical jets in a laboratory experiment

    NASA Astrophysics Data System (ADS)

    Bellan, Paul

    2006-04-01

    Astrophysical jets are routinely simulated in a reproducible, well-diagnosed laboratory experiment. The experimental sequence starts by imposing a vacuum poloidal magnetic field linking a disk electrode to a co-planar annular electrode. Neutral gas (H, Ne, N, or Ar) is then injected via 8 nozzles located on the disk and 8 nozzles on the annulus. A 120 μF capacitor bank power supply charged to 4-7 kV is applied via ignitron switches across the electrodes, breaking down the injected gas to form plasma. The low impedance (<10 mφ) of the highly conducting plasma causes the power supply to behave as a current source, rather than a voltage source. The discharging capacitor bank drives a ˜100 kA poloidal electric current through the plasma; this current initially flows in eight distinct `spider legs' (see photo in April meeting poster) that span from the disk to the annulus. The spider legs quickly merge via mutual attraction of their currents to form the simulated astrophysical jet. The axial gradient of the toroidal magnetic field energy density provides the force that accelerates the jet. The mass flux boundary condition at the electrodes is tightly coupled to the jet behavior. The jet is `fueled' by plasma ingested from the nozzles and the accumulation (pile-up) of the ingested plasma collimates the jet because of the associated pile-up of frozen-in toroidal magnetic flux convected with the plasma. The jet undergoes a kink instability when it becomes long enough to satisfy the Kruskal-Shafranov q=1 condition.

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

    PubMed

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

    2015-01-01

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

  15. Stochastic collision and aggregation analysis of kaolinite in water through experiments and the spheropolygon theory.

    PubMed

    Tang, Fiona H M; Alonso-Marroquin, Fernando; Maggi, Federico

    2014-04-15

    An approach based on spheropolygons (i.e., the Minkowski sum of a polygon with N vertices and a disk with spheroradius r) is presented to describe the shape of kaolinite aggregates in water and to investigate interparticle collision dynamics. Spheropolygons generated against images of kaolinite aggregates achieved an error between 0.5% and 20% as compared to at least 32% of equivalent spheres. These spheropolygons were used to investigate the probability of collision (Pr[C]) and aggregation (Pr[A]) under the action of gravitational, viscous, contact (visco-elastic), electrostatic and van der Waals forces. In ortho-axial (i.e., frontal) collision, Pr[A] of equivalent spheres was always 1, however, stochastic analysis of collision among spheropolygons showed that Pr[A] decreased asymptotically with N increasing, and decreased further in peri-axial (i.e., tangential) collision. Trajectory analysis showed that not all collisions occurring within the attraction zone of the double layer resulted in aggregation, neither all those occurring outside it led to relative departure. Rather, the relative motion on surface asperities affected the intensity of contact and attractive forces to an extent to substantially control a collision outcome in either instances. Spheropolygons revealed therefore how external shape can influence particle aggregation, and suggested that this is equally important to contact and double layer forces in determining the probability of particle aggregation.

  16. 2D ERT imaging of tracer dispersion in laboratory experiments

    NASA Astrophysics Data System (ADS)

    Lekmine, G.; Pessel, M.; Auradou, H.

    2009-12-01

    Electrical resistivity tomography applied in cross-borehole is a method often used to follow the invasion process of pollutants. The aim of this work is to test experimentally the electrode arrays and inversion processes used to obtain a spatial representation of tracer propagation in porous media. Experiments were conducted in a plexiglass container with glass beads of 166 microns in diameter. The height of the container is 275 mm, its width 85 mm and its thickness 10 mm. 21 electrodes, equally spaced, are placed along each of the lateral sides of the porous medium : these electrodes are used to perform the electrical measurements. The device is lightened from behind and a video camera records the fluid propagation. The tracer (i.e the pollutant) is a water solution containing a known amount of dye together with NaCl (0.5g/l up to 1.5g/l). The medium is first saturated by a water solution containing a slight concentration of NaCl so that its density is smaller than the tracer’s. An upward flow is first established, the denser fluid is injected at the bottom and over the full width of the medium. In this way, the flow is stabilized by gravity avoiding the development of unstable fingers. Still, the fluids are miscible and a mixing front develops during the flow: in the present study, the interest is to estimate the 2D tracer front dispersion by both optical and electrical imaging. The comparison of the two techniques allows to study the ability of the inversion process to quantify the solute transport. A sensitivity analysis is led in order to determine the best measurement sequence to monitor the tracer’s front evolution through the entire volume of the medium. Hence, each time step is constituted by the same 190 transverse dipole-dipole set of lasting 5 minutes between the first and the last measurement. At the laboratory scale, the experimental design affects the measurements through edges effects: most of these artefacts can be partially suppressed by using

  17. Research and Laboratory Instruction--An Experiment in Teaching

    ERIC Educational Resources Information Center

    Kramm, Kenneth R.

    1976-01-01

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

  18. Research and Laboratory Instruction--An Experiment in Teaching

    ERIC Educational Resources Information Center

    Kramm, Kenneth R.

    1976-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Taylor, Lawrence W., Jr. (Compiler)

    1990-01-01

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

  20. Internal quality assurance in cervical cytology one laboratory's experience.

    PubMed

    Cross, P A

    1996-02-01

    The results of an internal quality assurance exercise in one cervical cytology laboratory in England are presented, using different types of partial percentage re-screening of cervical smears. An overall false negative dyskaryotic rate of up to 4.3% was demonstrated, with the final cytology report diagnosis differing from the primary screening dignosis in 1.3% of cases. These finding are discussed, with the aim of helping to foster debate on the setting of national laboratory internal quality assurance standards.

  1. Laboratory experiments on fragmentation of highly-viscous bubbly syrup

    NASA Astrophysics Data System (ADS)

    Kurihara, H.; Kameda, M.; Ichihara, M.

    2006-12-01

    Fragmentation of vesicular magma by rapid decompression is a key process in explosive eruptions. To determine the fragmentation criteria, we carried out laboratory experiments on magma fragmentation using analogous materials. We used commercial syrup as an analogous material of magma, because the viscosity was widely altered by adding or subtracting water contents in the syrup. We made the bubbly syrup by adding hydrogen peroxide with manganese oxide in the syrup. The amount of hydrogen peroxide is proportional to the gas volume fraction in the syrup. We measured the rheological properties of the syrup. Zero shear viscosity η was measured by a rotating viscometer and a fiber elongation technique. Glass transition temperature was measured by differential scanning calorimetry. The measured data indicated that the temperature dependence of viscosity was described well using Williams-Landel-Ferry (WLF) equation. The solid content of syrup alters the viscosity as well as the glass transition temperature, though it may hardly affect the rigidity μ, which was measured by ultrasonic test in our previous work. We used a pressurized vertical tube with a large vacuum vessel to apply the rapid decompression on the material. An acrylic container, filled with the bubbly syrup, was placed in the bottom of the pressurized tube. By rupturing the diaphragms inserted between the tube and the vacuum vessel, the bubbly syrup is rapidly decompressed due to expansion of the pressurized gas in the tube. A high-speed video camera was used to obtain sequential images of the materials. Pressure transducers were mounted on the sidewall of the tube and the bottom of the container. The initial pressure was varied from 1 MPa to 5 MPa. The gas-volume fraction of the syrup under pressure was fixed as 2 % to 20%. The viscosity varied from 105 Pa·s to 108 Pa·s. We successfully observed three principal behaviors using the present analogous material; brittle fragmentation, partial fracture and

  2. Combining Laboratory Experiments with Digital Tools to Do Scientific Inquiry

    ERIC Educational Resources Information Center

    Kluge, Anders

    2014-01-01

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

  3. Combining Laboratory Experiments with Digital Tools to Do Scientific Inquiry

    ERIC Educational Resources Information Center

    Kluge, Anders

    2014-01-01

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

  4. Results (and future prospects) of the CMS experiment in photon-induced interactions in p-Pb collisions

    NASA Astrophysics Data System (ADS)

    Bylinkin, Alexander

    2017-03-01

    Exclusive vector meson photoproduction is studied in ultra-peripheral pPb collisions at √{sN N }=5.02 TeV with the CMS experiment at the LHC. The cross sections are measured as a function of the photon-proton centre-of-mass energy, extending the energy range explored by H1 and ZEUS Experiments at HERA. In addition, the differential cross sections (dσ/d|t|), where | t | ≈pT2 is the squared transverse momentum of produced vector mesons, are measured and the slope parameters are obtained. The results are compared to previous measurements and to theoretical predictions. Finally, prospect for further measurements of vector meson production that can be performed using the 2016 pPb collision data at 8 TeV to be collected at the end of the year are presented.

  5. Ks0 Ks0 correlations in pp collisions at √{ s} = 7 TeV from the LHC ALICE experiment

    NASA Astrophysics Data System (ADS)

    Abelev, B.; Adam, J.; Adamová, D.; Adare, A. M.; Aggarwal, M. M.; Aglieri Rinella, G.; Agocs, A. G.; Agostinelli, A.; Aguilar Salazar, S.; Ahammed, Z.; Ahmad Masoodi, A.; Ahmad, N.; Ahn, S. A.; Ahn, S. U.; Akindinov, A.; Aleksandrov, D.; Alessandro, B.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Almaráz Aviña, E.; Alme, J.; Alt, T.; Altini, V.; Altinpinar, S.; Altsybeev, I.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Anson, C.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arbor, N.; Arcelli, S.; Arend, A.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Asryan, A.; Augustinus, A.; Averbeck, R.; Awes, T. C.; Äystö, J.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bailhache, R.; Bala, R.; Baldini Ferroli, R.; Baldisseri, A.; Baldit, A.; Baltasar Dos Santos Pedrosa, F.; Bán, J.; Baral, R. C.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartke, J.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batyunya, B.; Baumann, C.; Bearden, I. G.; Beck, H.; Belikov, I.; Bellini, F.; Bellwied, R.; Belmont-Moreno, E.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bergognon, A. A. E.; Berzano, D.; Betev, L.; Bhasin, A.; Bhati, A. K.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Bjelogrlic, S.; Blanco, F.; Blanco, F.; Blau, D.; Blume, C.; Boccioli, M.; Bock, N.; Böttger, S.; Bogdanov, A.; Bøggild, H.; Bogolyubsky, M.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Bose, S.; Bossú, F.; Botje, M.; Boyer, B.; Braidot, E.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Browning, T. A.; Broz, M.; Brun, R.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Bugaiev, K.; Busch, O.; Buthelezi, Z.; Caballero Orduna, D.; Caffarri, D.; Cai, X.; Caines, H.; Calvo Villar, E.; Camerini, P.; Canoa Roman, V.; Cara Romeo, G.; Carena, F.; Carena, W.; Carlin Filho, N.; Carminati, F.; Carrillo Montoya, C. A.; Casanova Díaz, A.; Castillo Castellanos, J.; Castillo Hernandez, J. F.; Casula, E. A. R.; Catanescu, V.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chawla, I.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Coccetti, F.; Colamaria, F.; Colella, D.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Constantin, P.; Contin, G.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortese, P.; Cortés Maldonado, I.; Cosentino, M. R.; Costa, F.; Cotallo, M. E.; Crescio, E.; Crochet, P.; Cruz Alaniz, E.; Cuautle, E.; Cunqueiro, L.; Dainese, A.; Dalsgaard, H. H.; Danu, A.; Das, D.; Das, I.; Das, K.; Dash, S.; Dash, A.; de, S.; de Barros, G. O. V.; de Caro, A.; de Cataldo, G.; de Cuveland, J.; de Falco, A.; de Gruttola, D.; Delagrange, H.; Deloff, A.; Demanov, V.; De Marco, N.; Dénes, E.; de Pasquale, S.; Deppman, A.; D Erasmo, G.; de Rooij, R.; Diaz Corchero, M. A.; di Bari, D.; Dietel, T.; di Liberto, S.; di Mauro, A.; di Nezza, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domínguez, I.; Dönigus, B.; Dordic, O.; Driga, O.; Dubey, A. K.; Ducroux, L.; Dupieux, P.; Dutta Majumdar, M. R.; Dutta Majumdar, A. K.; Elia, D.; Emschermann, D.; Engel, H.; Erdal, H. A.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Eyyubova, G.; Fabris, D.; Faivre, J.; Falchieri, D.; Fantoni, A.; Fasel, M.; Fearick, R.; Fedunov, A.; Fehlker, D.; Feldkamp, L.; Felea, D.; Fenton-Olsen, B.; Feofilov, G.; Fernández Téllez, A.; Ferretti, A.; Ferretti, R.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Garabatos, C.; Garcia-Solis, E.; Garishvili, I.; Gerhard, J.; Germain, M.; Geuna, C.; Gheata, A.; Gheata, M.; Ghidini, B.; Ghosh, P.; Gianotti, P.; Girard, M. R.; Giubellino, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez, R.; Gonschior, A.; Ferreiro, E. G.; González-Trueba, L. H.; González-Zamora, P.; Gorbunov, S.; Goswami, A.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Grajcarek, R.; Grelli, A.; Grigoras, C.; Grigoras, A.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Gros, P.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerra Gutierrez, C.; Guerzoni, B.; Guilbaud, M.; Gulbrandsen, K.; Gunji, T.; Gupta, A.; Gupta, R.; Gutbrod, H.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Han, B. H.; Hanratty, L. D.; Hansen, A.; Harmanova, Z.; Harris, J. W.; Hartig, M.; Hasegan, D.; Hatzifotiadou, D.; Hayrapetyan, A.; Heckel, S. T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Herrmann, N.; Hess, B. A.; Hetland, K. F.; Hicks, B.; Hille, P. T.; Hippolyte, B.; Horaguchi, T.; Hori, Y.; Hristov, P.; Hřivnáčová, I.; Huang, M.; Humanic, T. J.; Hwang, D. S.; Ichou, R.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Incani, E.; Innocenti, G. M.; Innocenti, P. G.; Ippolitov, M.; Irfan, M.; Ivan, C.; Ivanov, V.; Ivanov, M.; Ivanov, A.; Ivanytskyi, O.; Jachołkowski, A.; Jacobs, P. M.; Jang, H. J.; Janik, M. A.; Janik, R.; Jayarathna, P. H. S. Y.; Jena, S.; Jha, D. M.; Jimenez Bustamante, R. T.; Jirden, L.; Jones, P. G.; Jung, H.; Jusko, A.; Kaidalov, A. B.; Kakoyan, V.; Kalcher, S.; Kaliňák, P.; Kalliokoski, T.; Kalweit, A.; Kanaki, K.; Kang, J. H.; Kaplin, V.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kazantsev, A.; Kebschull, U.; Keidel, R.; Khan, S. A.; Khan, M. M.; Khan, P.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, T.; Kim, D. W.; Kim, J. H.; Kim, J. S.; Kim, M.; Kim, B.; Kim, M.; Kim, S. H.; Kim, S.; Kim, D. J.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Klay, J. L.; Klein, J.; Klein-Bösing, C.; Kliemant, M.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Koch, K.; Köhler, M. K.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Konevskikh, A.; Korneev, A.; Kour, R.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kral, J.; Králik, I.; Kramer, F.; Kraus, I.; Krawutschke, T.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Krus, M.; Kryshen, E.; Krzewicki, M.; Kucheriaev, Y.; Kuhn, C.; Kuijer, P. G.; Kulakov, I.; Kumar, J.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, V.; Kushpil, S.; Kvaerno, H.; Kweon, M. J.; Kwon, Y.; Ladrón de Guevara, P.; Lakomov, I.; Langoy, R.; La Pointe, S. L.; Lara, C.; Lardeux, A.; La Rocca, P.; Lazzeroni, C.; Lea, R.; Le Bornec, Y.; Lechman, M.; Lee, S. C.; Lee, G. R.; Lee, K. S.; Lefèvre, F.; Lehnert, J.; Leistam, L.; Lenhardt, M.; Lenti, V.; León, H.; Leoncino, M.; León Monzón, I.; León Vargas, H.; Lévai, P.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Liu, L.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Lohn, S.; Lohner, D.; Loizides, C.; Loo, K. K.; Lopez, X.; López Torres, E.; Løvhøiden, G.; Lu, X.-G.; Luettig, P.; Lunardon, M.; Luo, J.; Luparello, G.; Luquin, L.; Luzzi, C.; Ma, R.; Ma, K.; Madagodahettige-Don, D. M.; Maevskaya, A.; Mager, M.; Mahapatra, D. P.; Maire, A.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Mangotra, L.; Manko, V.; Manso, F.; Manzari, V.; Mao, Y.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Marín, A.; Marin Tobon, C. A.; Markert, C.; Martashvili, I.; Martinengo, P.; Martínez, M. I.; Martínez Davalos, A.; Martínez García, G.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastromarco, M.; Mastroserio, A.; Matthews, Z. L.; Matyja, A.; Mayani, D.; Mayer, C.; Mazer, J.; Mazzoni, M. A.; Meddi, F.; Menchaca-Rocha, A.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Milano, L.; Milosevic, J.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitu, C.; Mlynarz, J.; Mohanty, B.; Mohanty, A. K.; Molnar, L.; Montaño Zetina, L.; Monteno, M.; Montes, E.; Moon, T.; Morando, M.; Moreira de Godoy, D. A.; Moretto, S.; Morsch, A.; Muccifora, V.; Mudnic, E.; Muhuri, S.; Mukherjee, M.; Müller, H.; Munhoz, M. G.; Musa, L.; Musso, A.; Nandi, B. K.; Nania, R.; Nappi, E.; Nattrass, C.; Naumov, N. P.; Navin, S.; Nayak, T. K.; Nazarenko, S.; Nazarov, G.; Nedosekin, A.; Niculescu, M.; Nielsen, B. S.; Niida, T.; Nikolaev, S.; Nikolic, V.; Nikulin, S.; Nikulin, V.; Nilsen, B. S.; Nilsson, M. S.; Noferini, F.; Nomokonov, P.; Nooren, G.; Novitzky, N.; Nyanin, A.; Nyatha, A.; Nygaard, C.; Nystrand, J.; Ochirov, A.; Oeschler, H.; Oh, S.; Oh, S. K.; Oleniacz, J.; Oppedisano, C.; Ortiz Velasquez, A.; Ortona, G.; Oskarsson, A.; Ostrowski, P.; Otwinowski, J.; Oyama, K.; Ozawa, K.; Pachmayer, Y.; Pachr, M.; Padilla, F.; Pagano, P.; Paić, G.; Painke, F.; Pajares, C.; Pal, S.; Pal, S. K.; Palaha, A.; Palmeri, A.; Papikyan, V.; Pappalardo, G. S.; Park, W. J.; Passfeld, A.; Pastirčák, B.; Patalakha, D. I.; Paticchio, V.; Pavlinov, A.; Pawlak, T.; Peitzmann, T.; Pereira da Costa, H.; Pereira de Oliveira Filho, E.; Peresunko, D.; Pérez Lara, C. E.; Perez Lezama, E.; Perini, D.; Perrino, D.; Peryt, W.; Pesci, A.; Peskov, V.; Pestov, Y.; Petráček, V.; Petran, M.; Petris, M.; Petrov, P.; Petrovici, M.; Petta, C.; Piano, S.; Piccotti, A.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Pitz, N.; Piyarathna, D. B.; Płoskoń, M.; Pluta, J.; Pocheptsov, T.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polák, K.; Polichtchouk, B.; Pop, A.; Porteboeuf-Houssais, S.; Pospíšil, V.; Potukuchi, B.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puchagin, S.; Puddu, G.; Pujol Teixido, J.; Pulvirenti, A.; Punin, V.; Putiš, M.; Putschke, J.; Quercigh, E.; Qvigstad, H.; Rachevski, A.; Rademakers, A.; Radomski, S.; Räihä, T. S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Ramírez Reyes, A.; Raniwala, S.; Raniwala, R.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Read, K. F.; Real, J. S.; Redlich, K.; Reichelt, P.; Reicher, M.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Riccati, L.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Rodrigues Fernandes Rabacal, B.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Rosnet, P.; Rossegger, S.; Rossi, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Ryabinkin, E.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahoo, R.; Sahu, P. K.; Saini, J.; Sakaguchi, H.; Sakai, S.; Sakata, D.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Šándor, L.; Sandoval, A.; Sano, S.; Sano, M.; Santo, R.; Santoro, R.; Sarkamo, J.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schreiner, S.; Schuchmann, S.; Schukraft, J.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Scott, P. A.; Segato, G.; Selyuzhenkov, I.; Senyukov, S.; Seo, J.; Serci, S.; Serradilla, E.; Sevcenco, A.; Shabetai, A.; Shabratova, G.; Shahoyan, R.; Sharma, N.; Sharma, S.; Rohni, S.; Shigaki, K.; Shimomura, M.; Shtejer, K.; Sibiriak, Y.; Siciliano, M.; Sicking, E.; Siddhanta, S.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, T.; Sinha, B. C.; Sitar, B.; Sitta, M.; Skaali, T. B.; Skjerdal, K.; Smakal, R.; Smirnov, N.; Snellings, R. J. M.; Søgaard, C.; Soltz, R.; Son, H.; Song, M.; Song, J.; Soos, C.; Soramel, F.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stan, I.; Stefanek, G.; Steinbeck, T.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Stolpovskiy, M.; Strabykin, K.; Strmen, P.; Suaide, A. A. P.; Subieta Vásquez, M. A.; Sugitate, T.; Suire, C.; Sukhorukov, M.; Sultanov, R.; Šumbera, M.; Susa, T.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szostak, A.; Szymanski, M.; Takahashi, J.; Tapia Takaki, J. D.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terrevoli, C.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Tlusty, D.; Toia, A.; Torii, H.; Toscano, L.; Truesdale, D.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ulery, J.; Ullaland, K.; Ulrich, J.; Uras, A.; Urbán, J.; Urciuoli, G. M.; Usai, G. L.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; van der Kolk, N.; Vande Vyvre, P.; van Leeuwen, M.; Vannucci, L.; Vargas, A.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vechernin, V.; Veldhoen, M.; Venaruzzo, M.; Vercellin, E.; Vergara, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Vikhlyantsev, O.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Viyogi, Y. P.; Vodopyanov, A.; Voloshin, K.; Voloshin, S.; Volpe, G.; von Haller, B.; Vranic, D.; Øvrebekk, G.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, V.; Wagner, B.; Wan, R.; Wang, M.; Wang, D.; Wang, Y.; Wang, Y.; Watanabe, K.; Weber, M.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilk, A.; Williams, M. C. S.; Windelband, B.; Xaplanteris Karampatsos, L.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, S.; Yasnopolskiy, S.; Yi, J.; Yin, Z.; Yoo, I.-K.; Yoon, J.; Yu, W.; Yuan, X.; Yushmanov, I.; Zach, C.; Zampolli, C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zelnicek, P.; Zgura, I. S.; Zhalov, M.; Zhang, X.; Zhang, H.; Zhou, F.; Zhou, D.; Zhou, Y.; Zhu, J.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zinovjev, G.; Zoccarato, Y.; Zynovyev, M.; Zyzak, M.; Alice Collaboration

    2012-10-01

    Identical neutral kaon pair correlations are measured in √{ s} = 7 TeV pp collisions in the ALICE experiment. One-dimensional Ks0 Ks0 correlation functions in terms of the invariant momentum difference of kaon pairs are formed in two multiplicity and two transverse momentum ranges. The femtoscopic parameters for the radius and correlation strength of the kaon source are extracted. The fit includes quantum statistics and final-state interactions of the a0 /f0 resonance. Ks0 Ks0 correlations show an increase in radius for increasing multiplicity and a slight decrease in radius for increasing transverse mass, mT, as seen in ππ correlations in pp collisions and in heavy-ion collisions. Transverse mass scaling is observed between the Ks0 Ks0 and ππ radii. Also, the first observation is made of the decay of the f2‧ (1525) meson into the Ks0 Ks0 channel in pp collisions.

  6. Constraint on Nuclear Symmetry Energy through Heavy RI Collision Experiment by Using SπRIT Device at RIBF-SAMURAI

    NASA Astrophysics Data System (ADS)

    Isobe, Tadaaki

    The symmetry energy of the nuclear Equation of State (EoS) is essential in many aspects of the astrophysics. However it has large ambiguity mainly for the dense region of ρ > ρ0. In order to give a constraint on the dencity dependent nuclear symmetry energy, an international experimental project at RIKEN-RIBF: SπRIT was launched. By using newly developed Time Projection Chamber (TPC) as a main device of SπRIT experiment, first heavy RI collision experiment was performed in the spring of 2016. In this experiment, charged π meson was measured as main observable as it is expected to be most sensitive to the symmetry energy.

  7. Insights from laboratory experiments into the physics of pyroclastic flows

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    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

  8. Isospin Effects in Heavy-Ion Collisions: Some Results From CHIMERA Experiments At LNS And Perspectives With Radioactive Beams

    SciTech Connect

    Cardella, G.; De Filippo, E.; Pagano, A.; Papa, M.; Pirrone, S.; Verde, G.; Amorini, F.; Cavallaro, S.; Lombardo, I.; Porto, F.; Rizzo, F.; Russotto, P.; Anzalone, A.; Maiolino, C.; Arena, N.; Geraci, E.; Grassi, L.; Lo Nigro, S.; Politi, G.; Auditore, L.

    2009-05-04

    CHIMERA is a 4{pi} multidetector for charged particles available at Laboratori Nazionali del Sud (INFN-LNS). A new method to measure the time scale of the emission of nuclear fragments is described, together with some applications in the field of the isospin dynamics of heavy-ion collisions. Competition between fusion-like and binary reactions near the energy threshold for nuclear multifragmentation is discussed. Opportunities are pointed out to use the detector at low and intermediate energies using the kinematical-coincidence method.

  9. Three-pion Hanbury Brown-Twiss correlations in relativistic heavy-ion collisions from the STAR experiment.

    PubMed

    Adams, J; Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Mora Corral, M; Cramer, J G; Crawford, H J; Derevschikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grachov, O; Guedon, M; Guertin, S M; Gushin, E; Gutierrez, T D; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Molnar, L; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Rykov, V; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Thompson, M; Timoshenko, S; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; Vander Molen, A M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Vznuzdaev, M; Wang, F; Wang, Y; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

    2003-12-31

    Data from the first physics run at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory, Au+Au collisions at sqrt[s(NN)]=130 GeV, have been analyzed by the STAR Collaboration using three-pion correlations with charged pions to study whether pions are emitted independently at freeze-out. We have made a high-statistics measurement of the three-pion correlation function and calculated the normalized three-particle correlator to obtain a quantitative measurement of the degree of chaoticity of the pion source. It is found that the degree of chaoticity seems to increase with increasing particle multiplicity.

  10. Three-pion Hanbury-Brown-Twiss correlations in relativistic heavy-ion collisions from the STAR experiment

    SciTech Connect

    Adams, J.; Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bichsel, H.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Botje, M.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R.V.; Cai, X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Cardenas, A.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Corral, Mora M.; Cramer, J.G.; Crawford, H.J.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Draper, J.E.; Dunin, V.B.; Dunlop, J.C.; Eckardt, V.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Grachov, O.; Guedon, M.; Guertin, S.M.; Gushin, E.; Gutierrez, T.D.; Hallman, T.J.; Hardtke, D.; Harris, J.W.; Heinz, M.; Henry, T.W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Humanic, T.J.; Igo, G.; Ishihara, A.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Kollegger, T.; Konstantinov, A.S.; Kopytine, M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A.I.; Kunde, G.J.; Kunz, C.L.; Kutuev, R.Kh.; Kuznetsov, A.A.; Lamont, M.A.C.; Landgraf, J.M.; Lange, S.; Lansdell, C.P.; Lasiuk, B.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Leontiev, V.M.; LeVine, M.J.; Li, Q.; Lindenbaum, S.J.; Lisa, M.A.; Liu, F.; Liu, L.; Liu, Q.J.; Liu, Z.; et al.

    2003-06-19

    Data from the first physics run at the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory, Au+Au collisions at {radical}s{sub NN} = 130 GeV, have been analyzed by the STAR Collaboration using three-pion correlations with charged pions to study whether pions are emitted independently at freezeout. We have made a high-statistics measurement of the three-pion correlation function and calculated the normalized three-particle correlator to obtain a quantitative measurement of the degree of chaoticity of the pion source. It is found that the degree of chaoticity seems to increase with increasing particle multiplicity.

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

    PubMed

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

    2013-12-01

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

  12. Development and Use of Online Prelaboratory Activities in Organic Chemistry to Improve Students' Laboratory Experience

    ERIC Educational Resources Information Center

    Chaytor, Jennifer L.; Al Mughalaq, Mohammad; Butler, Hailee

    2017-01-01

    Online prelaboratory videos and quizzes were prepared for all experiments in CHEM 231, Organic Chemistry I Laboratory. It was anticipated that watching the videos would help students be better prepared for the laboratory, decrease their anxiety surrounding the laboratory, and increase their understanding of the theories and concepts presented.…

  13. Collision Avoidance System

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Ames Research Center teamed with the Federal Aviation Administration (FAA) to study human performance factors associated with the use of the Traffic Alert and Collision Avoidance system (TCAS II) in an operational environment. TCAS is designed to alert pilots of the presence of other aircraft in their vicinity, to identify and track those who could be a threat, and to recommend action to avoid a collision. Ames conducted three laboratory experiments. The first showed that pilots were able to use the TCAS II correctly in the allowable time. The second tested pilots' response to changes in the avoidance advisories, and the third examined pilots' reactions to alternative displays. After a 1989 congressional mandate, the FAA ruled that TCAS would be required on all passenger carrying aircraft (to be phased in completely by 1995).

  14. The footprint of cometary dust analogues - I. Laboratory experiments of low-velocity impacts and comparison with Rosetta data

    NASA Astrophysics Data System (ADS)

    Ellerbroek, L. E.; Gundlach, B.; Landeck, A.; Dominik, C.; Blum, J.; Merouane, S.; Hilchenbach, M.; Bentley, M. S.; Mannel, T.; John, H.; van Veen, H. A.

    2017-07-01

    Cometary dust provides a unique window on dust growth mechanisms during the onset of planet formation. Measurements by the Rosetta spacecraft show that the dust in the coma of comet 67P/Churyumov-Gerasimenko has a granular structure at size scales from sub-μmup to several hundreds of μm, indicating hierarchical growth took place across these size scales. However, these dust particles may have been modified during their collection by the spacecraft instruments. Here, we present the results of laboratory experiments that simulate the impact of dust on the collection surfaces of the COSIMA (Cometary Secondary Ion Mass Anaylzer) and MIDAS (Micro-Imaging Dust Analysis System) instruments onboard the Rosetta spacecraft. We map the size and structure of the footprints left by the dust particles as a function of their initial size (up to several hundred μm) and velocity (up to 6 m s-1). We find that in most collisions, only part of the dust particle is left on the target; velocity is the main driver of the appearance of these deposits. A boundary between sticking/bouncing and fragmentation as an outcome of the particle-target collision is found at v ˜ 2 m s-1. For velocities below this value, particles either stick or leave a single deposit on the target plate, or bounce, leaving a shallow footprint of monomers. At velocities >2 m s-1and sizes >80 μm, particles fragment upon collision, transferring up to 50 per cent of their mass in a rubble-pile-like deposit on the target plate. The amount of mass transferred increases with the impact velocity. The morphologies of the deposits are qualitatively similar to those found by the COSIMA instrument.

  15. Laboratory experiments for defining scaling relations between rock material properties and rock resistance to erosion

    NASA Astrophysics Data System (ADS)

    Sklar, L. S.; Beyeler, J. D.; Collins, G. C.; Farrow, J. W.; Hsu, L.; Litwin, K. L.; Polito, P. J.

    2012-12-01

    Rock resistance to erosion is a key variable that limits rates of morphologic change and mass flux in landscapes. However, we have limited knowledge of how measurable material properties influence rock resistance to specific erosion processes. Rock 'erodibility' is commonly a free parameter in surface process models, where users assign or solve for numerical values that lack meaning outside of the model. Moreover, erodibility parameters often lump material resistance to erosion together with aspects of the forces driving erosion that are not explicitly represented in the model. Laboratory experiments in which rock types are varied, while erosive forces are held constant, can be used to develop scaling relationships between rock properties and erosion resistance for individual detachment mechanisms. With knowledge of why erosion rates vary between rock types for constant erosive forces, laboratory and field experiments that vary erosive intensity can be used to quantify the absolute susceptibility to erosion in physically explicit terms. Here we synthesize data collected over the past decade from a suite of laboratory investigations of rock resistance to wear by sediment particle impacts, and wear of sediment particles themselves, in experiments replicating fluvial and granular flow conditions. Materials tested included: field-sampled bedrock and sediment covering the widest feasible range of apparent durability and lithologic type; synthetic sandstones made from mixtures of sand and Portland cement; and water ice, both pure and containing solid impurities, tested over a wide range of temperatures. Material properties measured included: dry-bulk and saturated density, porosity, tensile strength, fracture toughness, elastic moduli, mineralogy, cement type, and the grain size of mineral crystals and cemented clasts. Erosion rates were measured by mass or volume loss divided by run time, in bedrock abrasion mills, barrel tumblers, and a large rotating drum. We find

  16. Designing Online Resources in Preparation for Authentic Laboratory Experiences

    PubMed Central

    Boulay, Rachel; Parisky, Alex; Leong, Peter

    2013-01-01

    Professional development for science teachers can be benefited through active learning in science laboratories. However, how online training materials can be used to complement traditional laboratory training is less understood. This paper explores the design of online training modules to teach molecular biology and user perception of those modules that were part of an intensive molecular biology “boot camp” targeting high school biology teachers in the State of Hawaii. The John A. Burns School of Medicine at the University of Hawaii had an opportunity to design and develop professional development that prepares science teachers with an introduction of skills, techniques, and applications for their students to conduct medical research in a laboratory setting. A group of 29 experienced teachers shared their opinions of the online materials and reported on how they used the online materials in their learning process or teaching. PMID:24319698

  17. Designing Online Resources in Preparation for Authentic Laboratory Experiences.

    PubMed

    Boulay, Rachel; Parisky, Alex; Leong, Peter

    2013-01-01

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

  18. Studies of relativistic heavy ion collisions at the AGS (Experiment 814). Annual progress report, 1 May 1991--30 April 1992

    SciTech Connect

    Cleland, W.E.

    1992-04-01

    During the past year, the Pittsburgh group has continued to work with the E814 collaboration in carrying out AGS Experiment 814. We present here a brief history of the experiment, followed by a detailed report of the analysis work being pursued at the University of Pittsburgh. As originally proposed, Experiment 814 is a study of both extreme peripheral collisions and the transition from peripheral to central collisions in relativistic heavy ion-nucleus interactions. We are studying relativistic heavy ion interactions with nuclei in two types of collisions: (a) extreme peripheral collisions of large impact parameter, and (b) central collisions with high transverse energy in the final state. The experiment emphasizes the measurement of overall event characteristics, in particular energy flow measurements and a precise measurement of the particle charge, momentum, and energy in the forward direction. This permits measurements of cross sections and rapidity densities as a function of the transverse energy for leading baryons emitted into regions of larger rapidity. Combining the energy flow measurements as a function of rapidity with the spectra of leading baryons provides information on the impact parameter dependence of the nuclear stopping of the projectile in relativistic heavy ion collisions. In 1988, the scope of Experiment 814 was enlarged to include a search for strange matter in central collisions, the first results of which have been published, and analysis on a longer run taken in 1990 is still under way.

  19. Whitson places cartridge into the ZCG experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-10-29

    ISS005-E-19055 (29 October 2002) --- Astronaut Peggy A. Whitson, Expedition Five flight engineer, inserts an experiment cartridge in the autoclave for the Zeolite Crystal Growth (ZCG) experiment in Destiny laboratory on the International Space Station (ISS).

  20. Progress of Jinping Underground laboratory for Nuclear Astrophysics experiment JUNA

    NASA Astrophysics Data System (ADS)

    Liu, Weiping

    2015-08-01

    Direct measurement of the cross sections for the key nuclear reactions in hydrostatic stellar evolution within Gamow window, which makes use of low background at deep underground laboratory, is crucial to solve key scientific questions in nuclear astrophysics. JUNA project aims at direct measurement of (α,γ), (α,n) reactions in hydrostatic helium burning and (p, γ), (p, α) reactions in hydrostatic hydrogen burning based on Jinping deep underground laboratory in China. The progress of experimental techniques, which include the accelerator system with high stability and high intensity, the detector system, and the shielding material with low background, will be presented.

  1. Some More Simple Laser Experiments for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Yap, F. Y.

    1969-01-01

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

  2. Some More Simple Laser Experiments for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Yap, F. Y.

    1969-01-01

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

  3. Laboratory Experiences in an Introduction to Natural Science Course.

    ERIC Educational Resources Information Center

    Barnard, Sister Marquita

    1984-01-01

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

  4. Restructuring a General Microbiology Laboratory into an Investigative Experience.

    ERIC Educational Resources Information Center

    Deutch, Charles E.

    1994-01-01

    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)

  5. Integrating Interdisciplinary Research-Based Experiences in Biotechnology Laboratories

    ERIC Educational Resources Information Center

    Iyer, Rupa S.; Wales, Melinda E.

    2012-01-01

    The increasingly interdisciplinary nature of today's scientific research is leading to the transformation of undergraduate education. In addressing these needs, the University of Houston's College of Technology has developed a new interdisciplinary research-based biotechnology laboratory curriculum. Using the pesticide degrading bacterium,…

  6. Argumentation in the Chemistry Laboratory: Inquiry and Confirmatory Experiments

    ERIC Educational Resources Information Center

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

    2013-01-01

    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…

  7. The Nature of Laboratory Learning Experiences in Secondary Science Online

    ERIC Educational Resources Information Center

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

    2013-01-01

    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…

  8. The Nature of Laboratory Learning Experiences in Secondary Science Online

    ERIC Educational Resources Information Center

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

    2013-01-01

    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…

  9. Students' Experience in a General Chemistry Cooperative Problem Based Laboratory

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  10. Raising Environmental Awareness through Applied Biochemistry Laboratory Experiments

    ERIC Educational Resources Information Center

    Salman Ashraf, S.

    2013-01-01

    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…

  11. Creatine Synthesis: An Undergraduate Organic Chemistry Laboratory Experiment

    ERIC Educational Resources Information Center

    Smith, Andri L.; Tan, Paula

    2006-01-01

    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…

  12. Creatine Synthesis: An Undergraduate Organic Chemistry Laboratory Experiment

    ERIC Educational Resources Information Center

    Smith, Andri L.; Tan, Paula

    2006-01-01

    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…

  13. Interactive Screen Experiments--Innovative Virtual Laboratories for Distance Learners

    ERIC Educational Resources Information Center

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

    2009-01-01

    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…

  14. 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...

  15. 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...

  16. Raising Environmental Awareness through Applied Biochemistry Laboratory Experiments

    ERIC Educational Resources Information Center

    Salman Ashraf, S.

    2013-01-01

    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…

  17. A Virtual Laboratory on Natural Computing: A Learning Experiment

    ERIC Educational Resources Information Center

    de Castro, Leandro Nunes; Muñoz, Yupanqui Julho; de Freitas, Leandro Rubim; El-Hani, Charbel Niño

    2008-01-01

    Natural computing is a terminology used to describe computational algorithms developed by taking inspiration from information processing mechanisms in nature, methods to synthesize natural phenomena in computers, and novel computational approaches based on natural materials. The virtual laboratory on natural computing (LVCoN) is a Web environment…

  18. Laboratory Experiences in an Introduction to Natural Science Course.

    ERIC Educational Resources Information Center

    Barnard, Sister Marquita

    1984-01-01

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

  19. Restructuring a General Microbiology Laboratory into an Investigative Experience.

    ERIC Educational Resources Information Center

    Deutch, Charles E.

    1994-01-01

    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)

  20. Laboratory Drop Towers for the Experimental Simulation of Dust-aggregate Collisions in the Early Solar System

    PubMed Central

    Blum, Jürgen; Beitz, Eike; Bukhari, Mohtashim; Gundlach, Bastian; Hagemann, Jan-Hendrik; Heißelmann, Daniel; Kothe, Stefan; Schräpler, Rainer; von Borstel, Ingo; Weidling, René

    2014-01-01

    For the purpose of investigating the evolution of dust aggregates in the early Solar System, we developed two vacuum drop towers in which fragile dust aggregates with sizes up to ~10 cm and porosities up to 70% can be collided. One of the drop towers is primarily used for very low impact speeds down to below 0.01 m/sec and makes use of a double release mechanism. Collisions are recorded in stereo-view by two high-speed cameras, which fall along the glass vacuum tube in the center-of-mass frame of the two dust aggregates. The other free-fall tower makes use of an electromagnetic accelerator that is capable of gently accelerating dust aggregates to up to 5 m/sec. In combination with the release of another dust aggregate to free fall, collision speeds up to ~10 m/sec can be achieved. Here, two fixed high-speed cameras record the collision events. In both drop towers, the dust aggregates are in free fall during the collision so that they are weightless and match the conditions in the early Solar System. PMID:24962693

  1. Laboratory drop towers for the experimental simulation of dust-aggregate collisions in the early solar system.

    PubMed

    Blum, Jürgen; Beitz, Eike; Bukhari, Mohtashim; Gundlach, Bastian; Hagemann, Jan-Hendrik; Heißelmann, Daniel; Kothe, Stefan; Schräpler, Rainer; von Borstel, Ingo; Weidling, René

    2014-06-05

    For the purpose of investigating the evolution of dust aggregates in the early Solar System, we developed two vacuum drop towers in which fragile dust aggregates with sizes up to ~10 cm and porosities up to 70% can be collided. One of the drop towers is primarily used for very low impact speeds down to below 0.01 m/sec and makes use of a double release mechanism. Collisions are recorded in stereo-view by two high-speed cameras, which fall along the glass vacuum tube in the center-of-mass frame of the two dust aggregates. The other free-fall tower makes use of an electromagnetic accelerator that is capable of gently accelerating dust aggregates to up to 5 m/sec. In combination with the release of another dust aggregate to free fall, collision speeds up to ~10 m/sec can be achieved. Here, two fixed high-speed cameras record the collision events. In both drop towers, the dust aggregates are in free fall during the collision so that they are weightless and match the conditions in the early Solar System.

  2. Laboratory Drop Towers for the Experimental Simulation of Dust-aggregate Collisions in the Early Solar System

    NASA Astrophysics Data System (ADS)

    Blum, Jürgen; Beitz, Eike; Bukhari, Mohtashim; Gundlach, Bastian; Hagemann, Jan-Hendrik; Heißelmann, Daniel; Kothe, Stefan; Schräpler, Rainer; von Borstel, Ingo; Weidling, René

    2014-06-01

    For the purpose of investigating the evolution of dust aggregates in the early Solar System, we developed two vacuum drop towers in which fragile dust aggregates with sizes up to ~10 cm and porosities up to 70% can be collided. One of the drop towers is primarily used for very low impact speeds down to below 0.01 m/sec and makes use of a double release mechanism. Collisions are recorded in stereo-view by two high-speed cameras, which fall along the glass vacuum tube in the center-of-mass frame of the two dust aggregates. The other free-fall tower makes use of an electromagnetic accelerator that is capable of gently accelerating dust aggregates to up to 5 m/sec. In combination with the release of another dust aggregate to free fall, collision speeds up to ~10 m/sec can be achieved. Here, two fixed high-speed cameras record the collision events. In both drop towers, the dust aggregates are in free fall during the collision so that they are weightless and match the conditions in the early Solar System.

  3. A Laboratory Experiment for Rapid Determination of the Stability of Vitamin C

    ERIC Educational Resources Information Center

    Adem, Seid M.; Lueng, Sam H.; Elles, Lisa M. Sharpe; Shaver, Lee Alan

    2016-01-01

    Experiments in laboratory manuals intended for general, organic, and biological (GOB) chemistry laboratories include few opportunities for students to engage in instrumental methods of analysis. Many of these students seek careers in modern health-related fields where experience in spectroscopic techniques would be beneficial. A simple, rapid,…

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

    ERIC Educational Resources Information Center

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

    2004-01-01

    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…

  5. A Laboratory Experiment for Rapid Determination of the Stability of Vitamin C

    ERIC Educational Resources Information Center

    Adem, Seid M.; Lueng, Sam H.; Elles, Lisa M. Sharpe; Shaver, Lee Alan

    2016-01-01

    Experiments in laboratory manuals intended for general, organic, and biological (GOB) chemistry laboratories include few opportunities for students to engage in instrumental methods of analysis. Many of these students seek careers in modern health-related fields where experience in spectroscopic techniques would be beneficial. A simple, rapid,…

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

    ERIC Educational Resources Information Center

    Gung, Benjamin W.; Taylor, Richard T.

    2004-01-01

    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.

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

    ERIC Educational Resources Information Center

    Bailey, James A.

    2011-01-01

    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…

  8. Green Fluorescent Protein-Focused Bioinformatics Laboratory Experiment Suitable for Undergraduates in Biochemistry Courses

    ERIC Educational Resources Information Center

    Rowe, Laura

    2017-01-01

    An introductory bioinformatics laboratory experiment focused on protein analysis has been developed that is suitable for undergraduate students in introductory biochemistry courses. The laboratory experiment is designed to be potentially used as a "stand-alone" activity in which students are introduced to basic bioinformatics tools and…

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

    ERIC Educational Resources Information Center

    Miller, P. J.; And Others

    1978-01-01

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

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

    ERIC Educational Resources Information Center

    Gung, Benjamin W.; Taylor, Richard T.

    2004-01-01

    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.

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

    ERIC Educational Resources Information Center

    Simon, Nicole A.

    2013-01-01

    Virtual laboratory experiments using interactive computer simulations are not being employed as viable alternatives to laboratory science curriculum at extensive enough rates within higher education. Rote traditional lab experiments are currently the norm and are not addressing inquiry, Critical Thinking, and cognition throughout the laboratory…

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

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

    ERIC Educational Resources Information Center

    Simon, Nicole A.

    2013-01-01

    Virtual laboratory experiments using interactive computer simulations are not being employed as viable alternatives to laboratory science curriculum at extensive enough rates within higher education. Rote traditional lab experiments are currently the norm and are not addressing inquiry, Critical Thinking, and cognition throughout the laboratory…

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

    ERIC Educational Resources Information Center

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

    2011-01-01

    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…

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

    ERIC Educational Resources Information Center

    Bailey, James A.

    2011-01-01

    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…

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

    ERIC Educational Resources Information Center

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

    2011-01-01

    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…

  18. Classroom Simulation as a Substitute for Live Pre-Student-Teaching Laboratory Experiences.

    ERIC Educational Resources Information Center

    Beals, Paul E.

    A study was conducted to observe differences in the teaching performance of students who had three different types of pre-student teaching laboratory experiences, some including simulation. Subjects were 75 student teachers who had been randomly assigned to three groups, each having different laboratory experiences, during the pre-student teaching…

  19. Concepts for unique laboratory astrophysics experiments on NIF

    NASA Astrophysics Data System (ADS)

    Remington, Bruce

    2008-11-01

    The ability to experimentally study scaled aspects of the explosion dynamics of core- collapse supernovae (massive stars that explode from the inside out) or the radiation kinetics of accreting neutron stars or black holes on high energy density (HED) facilities, such as the new National Ignition Facility (NIF), is an exciting scientific development. [``Experimental astrophysics with high power lasers and Z pinches,'' B.A. Remington, R.P. Drake, D.D. Ryutov, Rev. Mod. Phys. 78, 755 (2006)] Additional areas of research that could become accessible on NIF are studies of fundamental properties of matter in conditions relevant to the cores giant planets and stars, protostellar jet dynamics, radiatively driven molecular cloud dynamics, hyper-velocity (10-100 km/s) dust-dust collisions, and combined with ultraintense short-pulse lasers, pair plasma generation and dynamics, possibly relevant to gamma-ray burst physics. With the added tool of thermonuclear ignition on the National Ignition Facility, excited state (``multi-hit'') nuclear physics studies, and burn physics studies also become possible. Techniques and methodologies for studying aspects of the physics of such extreme phenomena of the universe in submillimeter scale parcels of matter on NIF will be discussed.

  20. An investigation of the effects of the common cold on simulated driving performance and detection of collisions: a laboratory study

    PubMed Central

    Jamson, Samantha

    2012-01-01

    Objective The aim of the present research was to investigate whether individuals with a common cold showed impaired ability on a simulated driving task and the ability to detect potential collisions between moving objects. Design The study involved comparison of a healthy group with a group with colds. These scores were adjusted for individual differences by collecting further data when both groups were healthy and using these scores as covariates. On both occasions, volunteers rated their symptoms and carried out a simulated driving session. On the first occasion, volunteers also carried out a collision detection task. Setting University of Leeds Institute for Transport Studies. Sample Twenty-five students from the University of Leeds. Ten volunteers were healthy on both occasions and 15 had a cold on the first session and were healthy on the second. Main outcome measures In the collision detection task, the main outcomes were correct detections and response to a secondary identification task. In the simulated driving task, the outcomes were speed, lateral control, gap acceptance, overtaking behaviour, car following, vigilance and traffic light violations. Results Those with a cold detected fewer collisions and had a higher divided attention error than those who were healthy. Many basic driving skills were unimpaired by the illness. However, those with a cold were slower at responding to unexpected events and spent a greater percentage of time driving at a headway of <2 s. Conclusions The finding that having a common cold is associated with reduced ability to detect collisions and respond quickly to unexpected events is of practical importance. Further research is now required to examine the efficacy of information campaigns and countermeasures such as caffeine. PMID:22761287

  1. Touring the Tomato: A Suite of Chemistry Laboratory Experiments

    PubMed Central

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

    2013-01-01

    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

  2. Touring the Tomato: A Suite of Chemistry Laboratory Experiments.

    PubMed

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

    2013-03-12

    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.

  3. Social setting, intuition and experience in laboratory experiments interact to shape cooperative decision-making.

    PubMed

    Capraro, Valerio; Cococcioni, Giorgia

    2015-07-22

    Recent studies suggest that cooperative decision-making in one-shot interactions is a history-dependent dynamic process: promoting intuition versus deliberation typically has a positive effect on cooperation (dynamism) among people living in a cooperative setting and with no previous experience in economic games on cooperation (history dependence). Here, we report on a laboratory experiment exploring how these findings transfer to a non-cooperative setting. We find two major results: (i) promoting intuition versus deliberation has no effect on cooperative behaviour among inexperienced subjects living in a non-cooperative setting; (ii) experienced subjects cooperate more than inexperienced subjects, but only under time pressure. These results suggest that cooperation is a learning process, rather than an instinctive impulse or a self-controlled choice, and that experience operates primarily via the channel of intuition. Our findings shed further light on the cognitive basis of human cooperative decision-making and provide further support for the recently proposed social heuristics hypothesis.

  4. Social setting, intuition and experience in laboratory experiments interact to shape cooperative decision-making

    PubMed Central

    Capraro, Valerio; Cococcioni, Giorgia

    2015-01-01

    Recent studies suggest that cooperative decision-making in one-shot interactions is a history-dependent dynamic process: promoting intuition versus deliberation typically has a positive effect on cooperation (dynamism) among people living in a cooperative setting and with no previous experience in economic games on cooperation (history dependence). Here, we report on a laboratory experiment exploring how these findings transfer to a non-cooperative setting. We find two major results: (i) promoting intuition versus deliberation has no effect on cooperative behaviour among inexperienced subjects living in a non-cooperative setting; (ii) experienced subjects cooperate more than inexperienced subjects, but only under time pressure. These results suggest that cooperation is a learning process, rather than an instinctive impulse or a self-controlled choice, and that experience operates primarily via the channel of intuition. Our findings shed further light on the cognitive basis of human cooperative decision-making and provide further support for the recently proposed social heuristics hypothesis. PMID:26156762

  5. PROTON - LAMBDA CORRELATIONS IN AU-AU COLLISIONS AT SQUARE ROOT NN = 200 GEV FROM THE STAR EXPERIMENT.

    SciTech Connect

    RENAULT,G.

    2004-03-15

    The space-time evolution of the source of particles formed in the collision of nuclei can be studied through particle correlations. The STAR experiment is dedicated to study ultra-relativistic heavy ions collisions and allows to measure non-identical strange particle correlations. The source size can be extracted by studying p - {Lambda}, {bar p} - {bar {Lambda}}, {bar p} - {Lambda} and p - {bar {Lambda}} correlation functions. Strong interaction potential has been studied for these systems using an analytical model. Final State Interaction (FSI) parameters have been determined and has shown a significant annihilation process present in {bar p} - {Lambda} and p - {bar {Lambda}} systems not present in p - {Lambda} and {bar p} - {bar {Lambda}}.

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

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  7. From laboratory plasma experiments to space plasma experiments with `CubeSat' nano-satellites

    NASA Astrophysics Data System (ADS)

    Charles, Christine

    2016-09-01

    `CubeSat' nano-satellites provide low-cost access to space. SP3 laboratory's involvement in the European Union `QB50' `CubeSat' project [www.qb50.eu] which will launch into space 50 `CubeSats' from 27 Countries to study the ionosphere and the lower thermosphere will be presented. The Chi Kung laboratory plasma experiment and the Helicon Double Layer Thruster prototype can be tailored to investigate expanding magnetized plasma physics relevant to space physics (solar corona, Earth's aurora, adiabatic expansion and polytropic studies). Chi Kung is also used as a plasma wind tunnel for ground-based calibration of the University College London QB50 Ion Neutral Mass Spectrometer. Space qualification of the three Australian QB50 `CubeSats' (June 2016) is carried out in the WOMBAT XL space simulation chamber. The QB50 satellites have attitude control but altitude control is not a requirement. SP3 is developing end-to-end miniaturised radiofrequency plasma propulsion systems (such as the Pocket Rocket and the MiniHel thrusters with power and propellant sub-systems) for future `CubeSat' missions.

  8. Reactions of Thiocyanate Ions with Acid: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Glidewell, Christopher; And Others

    1984-01-01

    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)

  9. A Semi-Batch Reactor Experiment for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Derevjanik, Mario; Badri, Solmaz; Barat, Robert

    2011-01-01

    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…

  10. Undergraduate Laboratory Experiment Modules for Probing Gold Nanoparticle Interfacial Phenomena

    ERIC Educational Resources Information Center

    Karunanayake, Akila G.; Gunatilake, Sameera R.; Ameer, Fathima S.; Gadogbe, Manuel; Smith, Laura; Mlsna, Deb; Zhang, Dongmao

    2015-01-01

    Three gold-nanoparticle (AuNP) undergraduate experiment modules that are focused on nanoparticles interfacial phenomena have been developed. Modules 1 and 2 explore the synthesis and characterization of AuNPs of different sizes but with the same total gold mass. These experiments enable students to determine how particle size affects the AuNP…

  11. Microcomputer-Based Digital Signal Processing Laboratory Experiments.

    ERIC Educational Resources Information Center

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

    1985-01-01

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

  12. The RC Circuit--A Multipurpose Laboratory Experiment.

    ERIC Educational Resources Information Center

    Wood, Herbert T.

    1993-01-01

    Describes an experiment that demonstrates the use of Kirchoff's rules in the analysis of electrical circuits. The experiment also involves the solution of a linear nonhomogeneous differential equation that is slightly different from the standard one for the simple RC circuit. (ZWH)

  13. A Cyclic Voltammetry Experiment for the Instrumental Analysis Laboratory.

    ERIC Educational Resources Information Center

    Baldwin, Richard P.; And Others

    1984-01-01

    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)

  14. A Cyclic Voltammetry Experiment for the Instrumental Analysis Laboratory.

    ERIC Educational Resources Information Center

    Baldwin, Richard P.; And Others

    1984-01-01

    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)

  15. A "Greenhouse Gas" Experiment for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  16. A Spectroscopic-Based Laboratory Experiment for Protein Conformational Studies

    ERIC Educational Resources Information Center

    Ramos, Carlos Henrique I.

    2004-01-01

    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…

  17. A "Greenhouse Gas" Experiment for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  18. A Spectroscopic-Based Laboratory Experiment for Protein Conformational Studies

    ERIC Educational Resources Information Center

    Ramos, Carlos Henrique I.

    2004-01-01

    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…

  19. A Thin Layer Chromatography Laboratory Experiment of Medical Importance

    ERIC Educational Resources Information Center

    Sharma, Loretta; Desai, Ankur; Sharma, Ajit

    2006-01-01

    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…

  20. A Semi-Batch Reactor Experiment for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Derevjanik, Mario; Badri, Solmaz; Barat, Robert

    2011-01-01

    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…

  1. A Membrane Gas Separation Experiment for the Undergraduate Laboratory.

    ERIC Educational Resources Information Center

    Davis, Richard A.; Sandall, Orville C.

    1991-01-01

    Described is a membrane experiment that provides students with experience in fundamental engineering skills such as mass balances, modeling, and using the computer as a research tool. Included are the experimental design, theory, method of solution, sample calculations, and conclusions. (KR)

  2. Reactions of Thiocyanate Ions with Acid: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Glidewell, Christopher; And Others

    1984-01-01

    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)

  3. Undergraduate Laboratory Experiment Modules for Probing Gold Nanoparticle Interfacial Phenomena

    ERIC Educational Resources Information Center

    Karunanayake, Akila G.; Gunatilake, Sameera R.; Ameer, Fathima S.; Gadogbe, Manuel; Smith, Laura; Mlsna, Deb; Zhang, Dongmao

    2015-01-01

    Three gold-nanoparticle (AuNP) undergraduate experiment modules that are focused on nanoparticles interfacial phenomena have been developed. Modules 1 and 2 explore the synthesis and characterization of AuNPs of different sizes but with the same total gold mass. These experiments enable students to determine how particle size affects the AuNP…

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

    ERIC Educational Resources Information Center

    Glidewell, Christopher; And Others

    1985-01-01

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

  5. A Thin Layer Chromatography Laboratory Experiment of Medical Importance

    ERIC Educational Resources Information Center

    Sharma, Loretta; Desai, Ankur; Sharma, Ajit

    2006-01-01

    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…

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

    ERIC Educational Resources Information Center

    Glidewell, Christopher; And Others

    1985-01-01

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

  7. Laser-driven ICF experiments: Laboratory Report No. 223

    SciTech Connect

    McCrory, R.L.

    1991-04-01

    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.

  8. Researches on interactions of satellite-speed helium atoms with aluminum and quartz surfaces. [atomic collisions with aluminum skin (structural member) of satellites (laboratory study)

    NASA Technical Reports Server (NTRS)

    Liu, S. M.; Knuth, E. L.

    1976-01-01

    Three major areas were experimentally studied: (1) energy transfer in collisions of satellite-speed (700 m/sec) helium atoms with a cleaned satellite-type aluminum surface was investigated using the molecular-beam technique. Spatial and energy distributions of reflected helium atoms were measured and analyzed, (2) The gross accommodation coefficient for a satellite-speed (7000 m/sec) helium beam entering a 2-inch-diameter aluminum spherical cavity was determined by measuring the exit velocity distribution of the leaving helium atoms using a metastable time-of-flight method. Results indicate that the 7000-m/sec satellite-speed helium atoms entering the cavity gain full accommodation with the room-temperature inner surface of the sphere through a large number of collisions before leaving the spherical cavity; and (3) the feasibility of producing a satellite-speed atomic hydrogen beam by arc-heating, for use in studies of interactions of satellite-surfaces with hydrogen atoms under laboratory conditions, was investigated. It was found that a stable arc-heated molecular hydrogen beam can be obtained using the arc-heater, and that a partially dissociated hydrogen beam can be produced. Photographs of laboratory equipment are shown.

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

    NASA Astrophysics Data System (ADS)

    Kirk, Maria Kristine

    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.

  10. J/psi yield modification in 200 GeV per nucleon AU+AU collisions with the PHENIX experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Klatsky, Jeffrey Curry

    It has been believed for over 30 years that matter will become a deconfined state of quarks and. gluons at sufficiently high energy densities. As the energy density increases, deconfinement occurs. due to Debye screening of the color charges, which disrupts the binding of mesons and baryons. The. expected deconfinement transition to quark-gluon plasma (QGP) has been observed using collisions. of heavy ions to create high energy densities,first at the Relativistic Heavy Ion Collider (RHIC). at Brookhaven National Laboratory, and more recently at the Large Hadron Collider (LHC) at. European Organization for Nuclear Research (CERN). The degree to which the binding of a hadron in the plasma is disrupted depends on its radius. Because deconfinement is caused by Debye screening, and the screening length is determined by. energy density, small tightly bound heavy quark mesons (referred to as quarkonia) may become. deconfined at a higher energy density than the light quark hadrons. Thus, measuring quarkonia. production may provide a way to determine the screening length in the QGP, and a program of. measurements of modification of charmonium and bottomonium states in heavy ion collisions has. been carried out at several accelerators over the last two decades. As part of this effort, measurements of J/psi production in Au+Au collisions have been made by the. PHENIX experiment at RHIC, the subject of this thesis. Specifically, J/psi --> e+e- data from. Sqrt(sNN) = 200 GeV Au+Au collisions were recorded in 2004, providing the first major quarkonia result from PHENIX. A higher statistics measurement was performed in 2007, but a non-functioning detector. subsystem in the PHENIX central arms rendered the data unusable. A still larger data set was. recorded 2010, this time with the previously non-functioning detector system working. It is these. 2010 data that are the focus of the present analysis. The 2010 dataset contains about 5 times as many measured J/psi as the 2004 dataset

  11. Laboratory dust experiments - Tracing the composition of cometary dust

    NASA Technical Reports Server (NTRS)

    Greenberg, J. M.

    1983-01-01

    The structure and composition of the comet nucleus are investigated theoretically on the basis of aggregation models and laboratory simulations of interstellar-grain evolution. The results are presented in graphs, diagrams, and drawings and discussed in detail. The nucleus is described as a loose tangle of rodlike grains containing about 28 percent H2O, 10 percent CO2 and CO, and 33 percent nonvolatile submicron-size grit particles (silicates, complex organics, and carbon). Evidence from meteorites suggests that the C-12/C-13 ratio of the volatile components is greater than 100.

  12. Zero-gravity atmospheric Cloud Physics Experiment Laboratory; Programmatics report

    NASA Technical Reports Server (NTRS)

    1974-01-01

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

  13. Laboratory experiments duplicate conditions in the Earth’s crust

    USGS Publications Warehouse

    Peselnick, L.; Dieterich, J.H.; Stewart, R.M.

    1974-01-01

    An experimental device that simulates conditions in the Earth's crust at depths of up to 30 kilometers has been constructed by geophysicists working at the U.S Geological Survey laboratories in Menlo Park, California. A high pressure "bomb" is being used to experimentally measure the velocity of seismic waves in different types of rock at various confining pressures and temperatures. The principal purpose of these measurements is to determine the elastic and non-elastic properties of rocks and minerals under conditions of high-pressure such as exist deep in the Earth's crust. 

  14. Laboratory experiments of relevance to the space station environment

    NASA Technical Reports Server (NTRS)

    Caledonia, G. E.

    1988-01-01

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

  15. Absorption spectroscopy of a laboratory photoionized plasma experiment at Z

    SciTech Connect

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

    2014-03-15

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

  16. Metallo Complexes: An Experiment for the Undergraduate Laboratory.

    ERIC Educational Resources Information Center

    Kauffman, George B.; And Others

    1984-01-01

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

  17. 4,5-Diphenyl-1-methylimidazole: An Undergraduate Laboratory Experiment.

    ERIC Educational Resources Information Center

    Anastas, Paul T.; And Others

    1985-01-01

    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)

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

    ERIC Educational Resources Information Center

    Berkovic, G.

    1984-01-01

    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)

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

    ERIC Educational Resources Information Center

    Touvelle, Michele; Venugopalan, Mundiyath

    1986-01-01

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

  20. The Semipermeability of Biological Membranes: An Undergraduate Laboratory Experiment.

    ERIC Educational Resources Information Center

    Frimer, Aryeh A.

    1985-01-01

    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)