Sample records for laboratory deformation experiments

  1. 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

  2. Developing a Virtual Rock Deformation Laboratory

    NASA Astrophysics Data System (ADS)

    Zhu, W.; Ougier-simonin, A.; Lisabeth, H. P.; Banker, J. S.

    2012-12-01

    addition, some web based data collection tools are available to collect student feedback and opinions on their learning experience. The virtual laboratory is designed to be an online education tool that facilitates interactive learning.; Virtual Deformation Laboratory

  3. Spectral Characteristics of Continuous Acoustic Emission (AE) Data from Laboratory Rock Deformation Experiments

    NASA Astrophysics Data System (ADS)

    Flynn, J. William; Goodfellow, Sebastian; Reyes-Montes, Juan; Nasseri, Farzine; Young, R. Paul

    2016-04-01

    Continuous acoustic emission (AE) data recorded during rock deformation tests facilitates the monitoring of fracture initiation and propagation due to applied stress changes. Changes in the frequency and energy content of AE waveforms have been previously observed and were associated with microcrack coalescence and the induction or mobilisation of large fractures which are naturally associated with larger amplitude AE events and lower-frequency components. The shift from high to low dominant frequency components during the late stages of the deformation experiment, as the rate of AE events increases and the sample approaches failure, indicates a transition from the micro-cracking to macro-cracking regime, where large cracks generated result in material failure. The objective of this study is to extract information on the fracturing process from the acoustic records around sample failure, where the fast occurrence of AE events does not allow for identification of individual AE events and phase arrivals. Standard AE event processing techniques are not suitable for extracting this information at these stages. Instead the observed changes in the frequency content of the continuous record can be used to characterise and investigate the fracture process at the stage of microcrack coalescence and sample failure. To analyse and characterise these changes, a detailed non-linear and non-stationary time-frequency analysis of the continuous waveform data is required. Empirical Mode Decomposition (EMD) and Hilbert Spectral Analysis (HSA) are two of the techniques used in this paper to analyse the acoustic records which provide a high-resolution temporal frequency distribution of the data. In this paper we present the results from our analysis of continuous AE data recorded during a laboratory triaxial deformation experiment using the combined EMD and HSA method.

  4. Strain Localization and Weakening Processes in Viscously Deforming Rocks: Numerical Modeling Based on Laboratory Torsion Experiments

    NASA Astrophysics Data System (ADS)

    Doehmann, M.; Brune, S.; Nardini, L.; Rybacki, E.; Dresen, G.

    2017-12-01

    Strain localization is an ubiquitous process in earth materials observed over a broad range of scales in space and time. Localized deformation and the formation of shear zones and faults typically involves material softening by various processes, like shear heating and grain size reduction. Numerical modeling enables us to study the complex physical and chemical weakening processes by separating the effect of individual parameters and boundary conditions. Using simple piece-wise linear functions for the parametrization of weakening processes allows studying a system at a chosen (lower) level of complexity (e.g. Cyprych et al., 2016). In this study, we utilize a finite element model to test two weakening laws that reduce the strength of the material depending on either the I) amount of accumulated strain or II) deformational work. Our 2D Cartesian models are benchmarked to single inclusion torsion experiments performed at elevated temperatures of 900 °C and pressures of up to 400 MPa (Rybacki et al., 2014). The experiments were performed on Carrara marble samples containing a weak Solnhofen limestone inclusion at a maximum strain rate of 2.0*10-4 s-1. Our models are designed to reproduce shear deformation of a hollow cylinder equivalent to the laboratory setup, such that material leaving one side of the model in shear direction enters again on the opposite side using periodic boundary conditions. Similar to the laboratory tests, we applied constant strain rate and constant stress boundary conditions.We use our model to investigate the time-dependent distribution of stress and strain and the effect of different parameters. For instance, inclusion rotation is shown to be strongly dependent on the viscosity ratio between matrix and inclusion and stronger ductile weakening increases the localization rate while decreasing shear zone width. The most suitable weakening law for representation of ductile rock is determined by combining the results of parameter tests with

  5. A Deformable Atlas of the Laboratory Mouse

    PubMed Central

    Wang, Hongkai; Stout, David B.; Chatziioannou, Arion F.

    2015-01-01

    Purpose This paper presents a deformable mouse atlas of the laboratory mouse anatomy. This atlas is fully articulated and can be positioned into arbitrary body poses. The atlas can also adapt body weight by changing body length and fat amount. Procedures A training set of 103 micro-CT images was used to construct the atlas. A cage-based deformation method was applied to realize the articulated pose change. The weight-related body deformation was learned from the training set using a linear regression method. A conditional Gaussian model and thin-plate spline mapping were used to deform the internal organs following the changes of pose and weight. Results The atlas was deformed into different body poses and weights, and the deformation results were more realistic compared to the results achieved with other mouse atlases. The organ weights of this atlas matched well with the measurements of real mouse organ weights. This atlas can also be converted into voxelized images with labeled organs, pseudo CT images and tetrahedral mesh for phantom studies. Conclusions With the unique ability of articulated pose and weight changes, the deformable laboratory mouse atlas can become a valuable tool for preclinical image analysis. PMID:25049072

  6. The instantaneous rate dependence in low temperature laboratory rock friction and rock deformation experiments

    USGS Publications Warehouse

    Beeler, N.M.; Tullis, T.E.; Kronenberg, A.K.; Reinen, L.A.

    2007-01-01

    Earthquake occurrence probabilities that account for stress transfer and time-dependent failure depend on the product of the effective normal stress and a lab-derived dimensionless coefficient a. This coefficient describes the instantaneous dependence of fault strength on deformation rate, and determines the duration of precursory slip. Although an instantaneous rate dependence is observed for fracture, friction, crack growth, and low temperature plasticity in laboratory experiments, the physical origin of this effect during earthquake faulting is obscure. We examine this rate dependence in laboratory experiments on different rock types using a normalization scheme modified from one proposed by Tullis and Weeks [1987]. We compare the instantaneous rate dependence in rock friction with rate dependence measurements from higher temperature dislocation glide experiments. The same normalization scheme is used to compare rate dependence in friction to rock fracture and to low-temperature crack growth tests. For particular weak phyllosilicate minerals, the instantaneous friction rate dependence is consistent with dislocation glide. In intact rock failure tests, for each rock type considered, the instantaneous rate dependence is the same size as for friction, suggesting a common physical origin. During subcritical crack growth in strong quartzofeldspathic and carbonate rock where glide is not possible, the instantaneous rate dependence measured during failure or creep tests at high stress has long been thought to be due to crack growth; however, direct comparison between crack growth and friction tests shows poor agreement. The crack growth rate dependence appears to be higher than the rate dependence of friction and fracture by a factor of two to three for all rock types considered. Copyright 2007 by the American Geophysical Union.

  7. Coupled deformation and dehydration processes in smectite-rich sediments constrained by laboratory experiments

    NASA Astrophysics Data System (ADS)

    Huepers, Andre; Kopf, Achim J.

    2013-04-01

    Subduction zones play a central role in the geological activity of the earth which is expressed as devastating events such as earthquakes, tsunamis and explosive volcanism. Many processes that lead to such catastrophic behavior are driven by fluids, which in turn affect the rock mechanical behavior. The kinetic reaction of hydrous smectite to illite is widely accepted as a fluid source in subduction zone forearcs that also affects the mechanical state of subduction zone sediments. The released fluids are characterized by low-chlorinity and high volatile content. Also, previous workers demonstrated in uniaxial deformation tests that smectite partially dehydrates with increasing effective stress. To shed light on this process we performed uniaxial deformation experiments on smectite-rich samples from the Nankai and Costa Rica subduction zones. Experiments were conducted at temperatures of up to 100°C under constant rate of strain and effective stresses of up to ~100MPa. Fluids expelled during the experiments were analyzed for major and minor element content. The fluids are characterized by fluid-freshening and increasing volatile content that starts at ~1.3MPa effective stress. During the course of the experiments the smectite interlayer water content decreases from 27 wt-% to 20 wt-%. The released interlayer water comprises up to 17% of the total fluid volume released from the consolidating sediment. The onset of fluid freshening is characterized by a change in deformation behavior of the samples. The porosity decrease with increasing effective stress is smaller at effective stresses greater 1.3MPa. We propose that dehydration of the low permeable smectite leads to excess pore pressures in the sample, which causes a load transfer from the solid phase to the pore fluid.

  8. Laboratory determination of effective stress laws for deformation and permeability of chalk

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Teufel, L W; Warpinski, N R

    1990-01-01

    Laboratory deformation and permeability measurements have been made on chalk samples from Ekofisk area fields as a function of confining stress and pore pressure to determine the effective stress laws for chalk. An understanding of the effective stress law is essential to obtain correct reservoir-property data from core analysis and is critical for reservoir management studies and reservoir compaction models. A powerful statistical technique known as the response surface method has been used to analyze our laboratory data determine the form of the effective stress law for deformation and permeability. Experiments were conducted on chalk samples that had a rangemore » of porosities from 15% to 36%, because porosity is the dominant intrinsic property that effects deformation and permeability behavior of chalk. Deformation of a 36% porosity chalk was highly nonlinear, but the effective stress law was linear, with {alpha} equal to about unity. Lower-porosity samples showed linear strain behavior and a linear effective stress law with {alpha} as low as 0.74. Analysis of the effective stress law for permeability is presented only for the lowest porosity chalk sample because changes in permeability in the higher-porosity chalk samples due to increasing confining stress or pore pressure were not were large enough, to deduce meaningful effective stress relationships. 15 refs., 8 figs., 2 tabs.« less

  9. 3D mapping of turbulence: a laboratory experiment

    NASA Astrophysics Data System (ADS)

    Le Louarn, Miska; Dainty, Christopher; Paterson, Carl; Tallon, Michel

    2000-07-01

    In this paper, we present the first experimental results of the 3D mapping method. 3D mapping of turbulence is a method to remove the cone effect with multiple laser guide stars and multiple deformable mirrors. A laboratory experiment was realized to verify the theoretical predictions. The setup consisted of two turbulent phase screens (made with liquid crystal devices) and a Shack-Hartmann wavefront sensor. We describe the interaction matrix involved in reconstructing Zernike commands for multiple deformable mirror from the slope measurements made from laser guide stars. It is shown that mirror commands can indeed be reconstructed with the 3D mapping method. Limiting factors of the method, brought to light by this experiment are discussed.

  10. Microstructural and mechanical evolution during deformation and annealing of poly-phase marbles - constraints from laboratory experiments and field observations

    NASA Astrophysics Data System (ADS)

    Austin, N. J.; Evans, B.; Dresen, G. H.; Rybacki, E.

    2009-12-01

    Deformed rocks commonly consist of several mineral phases, each with dramatically different mechanical properties. In both naturally and experimentally deformed rocks, deformation mechanisms and, in turn, strength, are commonly investigated by analyzing microstructural elements such as crystallographic preferred orientation (CPO) and recrystallized grain size. Here, we investigated the effect of variations in the volume fraction and the geometry of rigid second phases on the strength and evolution of CPO and grain size of synthetic calcite rocks. Experiments using triaxial compression and torsional loading were conducted at 1023 K and equivalent strain rates between ~2e-6 and 1e-3 s-1. The second phases in these synthetic assemblages are rigid carbon spheres or splinters with known particle size distributions and geometries, which are chemically inert at our experimental conditions. Under hydrostatic conditions, the addition of as little as 1 vol.% carbon spheres poisons normal grain growth. Shape is also important: for an equivalent volume fraction and grain dimension, carbon splinters result in a finer calcite grain size than carbon spheres. In samples deformed at “high” strain rates, or which have “large” mean free spacing of the pinning phase, the final recrystallized grain size is well explained by competing grain growth and grain size reduction processes, where the grain-size reduction rate is determined by the rate that mechanical work is done during deformation. In these samples, the final grain size is finer than in samples heat-treated hydrostatically for equivalent durations. The addition of 1 vol.% spheres to calcite has little effect on either the strength or CPO development. Adding 10 vol.% splinters increases the strength at low strains and low strain rates, but has little effect on the strength at high strains and/or high strain rates, compared to pure samples. A CPO similar to that in pure samples is observed, although the intensity is

  11. Radionuclide migration: laboratory experiments with isolated fractures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

  12. Nuclear deformation in the laboratory frame

    NASA Astrophysics Data System (ADS)

    Gilbreth, C. N.; Alhassid, Y.; Bertsch, G. F.

    2018-01-01

    We develop a formalism for calculating the distribution of the axial quadrupole operator in the laboratory frame within the rotationally invariant framework of the configuration-interaction shell model. The calculation is carried out using a finite-temperature auxiliary-field quantum Monte Carlo method. We apply this formalism to isotope chains of even-mass samarium and neodymium nuclei and show that the quadrupole distribution provides a model-independent signature of nuclear deformation. Two technical advances are described that greatly facilitate the calculations. The first is to exploit the rotational invariance of the underlying Hamiltonian to reduce the statistical fluctuations in the Monte Carlo calculations. The second is to determine quadruple invariants from the distribution of the axial quadrupole operator in the laboratory frame. This allows us to extract effective values of the intrinsic quadrupole shape parameters without invoking an intrinsic frame or a mean-field approximation.

  13. A Bed-Deformation Experiment Beneath Engabreen, Norway

    NASA Astrophysics Data System (ADS)

    Iverson, N. R.; Hooyer, T. S.; Fischer, U. H.; Cohen, D.; Jackson, M.; Moore, P. L.; Lappegard, G.; Kohler, J.

    2001-12-01

    Although deformation of sediment beneath ice masses may contribute to their motion and may sometimes enable fast glacier flow, both the kinematics and mechanics of deformation are controversial. This controversy stems, in part, from subglacial measurements that are difficult to interpret. Measurements have been made either beneath ice margins or remotely through boreholes with interpretive limitations caused by uncertain instrument position and performance, uncertain sediment thickness and bed geometry, and unknown disturbance of the bed and stress state by drilling. We have used a different approach made possible by the Svartisen Subglacial Laboratory, which enables human access to the bed of Engabreen, Norway, beneath 230 m of temperate ice. A trough (2 m x 1.5 m x 0.4 m deep) was blasted in the rock bed and filled with sediment (75 percent sand and gravel, 20 percent silt, 5 percent clay). Instruments were placed in the sediment to record shear deformation (tiltmeters), dilation and contraction, total normal stress, and pore-water pressure. Pore pressure was manipulated by feeding water to the base of the sediment with a high-pressure pump, operated in a rock tunnel 4 m below the bed surface. After irregular deformation during closure of ice on the sediment, shear deformation and volume change stopped, and total normal stress became constant at 2.2 MPa. Subsequent pump tests, which lasted several hours, induced pore-water pressures greater than 70 percent of the total normal stress and resulted in shear deformation over most of the sediment thickness with attendant dilation. Ice separated from the sediment when effective normal stress was lowest, arresting shear deformation. Displacement profiles during pump tests were similar to those observed by Boulton and co-workers at Breidamerkurjökull, Iceland, with rates of shear strain increasing upward toward the glacier sole. Such deformation does not require viscous deformation resistance and is expected in a

  14. Bed-Deformation Experiments Beneath a Temperate Glacier

    NASA Astrophysics Data System (ADS)

    Iverson, N. R.; Hooyer, T. S.; Fischer, U. H.; Cohen, D.; Jackson, M.; Moore, P. L.; Lappegard, G.; Kohler, J.

    2002-12-01

    Fast flow of glaciers and genesis of glacial landforms are commonly attributed to shear deformation of subglacial sediment. Although models of this process abound, data gathered subglacially on the kinematics and mechanics of such deformation are difficult to interpret. Major difficulties stem from the necessity of either measuring deformation near glacier margins, where conditions may be abnormal, or at the bottoms of boreholes, where the scope of instrumentation is limited, drilling disturbs sediment, and local boundary conditions are poorly known. A different approach is possible at the Svartisen Subglacial Laboratory, where tunnels melted in the ice provide temporary human access to the bed of Engabreen, a temperate outlet glacier of the Svartisen Ice Cap in Norway. A trough (2 m x 1.5 m x 0.5 m deep) was blasted in the rock bed, where the glacier is 220 m thick and sliding at 0.1-0.2 m/d. During two spring field seasons, this trough was filled with 2.5 tons of simulated till. Instruments in the till recorded shear (tiltmeters), volume change, total normal stress, and pore-water pressure as ice moved across the till surface. Pore pressure was brought to near the total normal stress by feeding water to the base of the till with a high-pressure pump, operated in a rock tunnel 4 m below the bed surface. Results illustrate some fundamental aspects of bed deformation. Permanent shear deformation requires low effective normal stress and hence high pore-water pressure, owing to the frictional nature of till. Shear strain generally increases upward in the bed toward the glacier sole, consistent with previous measurements beneath thinner ice at glacier margins. At low effective normal stresses, ice sometimes decouples from underlying till. Overall, bed deformation accounts for 10-35 % of basal motion, although this range excludes shear in the uppermost 0.05 m of till where shear was not measured. Pump tests with durations ranging from seconds to hours highlight the need

  15. Deformation of volcanic materials by pore pressurization: analog experiments with simplified geometry

    NASA Astrophysics Data System (ADS)

    Hyman, David; Bursik, Marcus

    2018-03-01

    The pressurization of pore fluids plays a significant role in deforming volcanic materials; however, understanding of this process remains incomplete, especially scenarios accompanying phreatic eruptions. Analog experiments presented here use a simple geometry to study the mechanics of this type of deformation. Syrup was injected into the base of a sand medium, simulating the permeable flow of fluids through shallow volcanic systems. The experiments examined surface deformation over many source depths and pressures. Surface deformation was recorded using a Microsoft® Kinect™ sensor, generating high-spatiotemporal resolution lab-scale digital elevation models (DEMs). The behavior of the system is controlled by the ratio of pore pressure to lithostatic loading (λ =p/ρ g D). For λ <10, deformation was accommodated by high-angle, reversed-mechanism shearing along which fluid preferentially flowed, leading to a continuous feedback between deformation and pressurization wherein higher pressure ratios yielded larger deformations. For λ >10, fluid expulsion from the layer was much faster, vertically fracturing to the surface with larger pressure ratios yielding less deformation. The temporal behavior of deformation followed a characteristic evolution that produced an approximately exponential increase in deformation with time until complete layer penetration. This process is distinguished from magmatic sources in continuous geodetic data by its rapidity and characteristic time evolution. The time evolution of the experiments compares well with tilt records from Mt. Ontake, Japan, in the lead-up to the deadly 2014 phreatic eruption. Improved understanding of this process may guide the evolution of magmatic intrusions such as dikes, cone sheets, and cryptodomes and contribute to caldera resurgence or deformation that destabilizes volcanic flanks.

  16. Investigating Brittle Rock Failure and Associated Seismicity Using Laboratory Experiments and Numerical Simulations

    NASA Astrophysics Data System (ADS)

    Zhao, Qi

    Rock failure process is a complex phenomenon that involves elastic and plastic deformation, microscopic cracking, macroscopic fracturing, and frictional slipping of fractures. Understanding this complex behaviour has been the focus of a significant amount of research. In this work, the combined finite-discrete element method (FDEM) was first employed to study (1) the influence of rock discontinuities on hydraulic fracturing and associated seismicity and (2) the influence of in-situ stress on seismic behaviour. Simulated seismic events were analyzed using post-processing tools including frequency-magnitude distribution (b-value), spatial fractal dimension (D-value), seismic rate, and fracture clustering. These simulations demonstrated that at the local scale, fractures tended to propagate following the rock mass discontinuities; while at reservoir scale, they developed in the direction parallel to the maximum in-situ stress. Moreover, seismic signature (i.e., b-value, D-value, and seismic rate) can help to distinguish different phases of the failure process. The FDEM modelling technique and developed analysis tools were then coupled with laboratory experiments to further investigate the different phases of the progressive rock failure process. Firstly, a uniaxial compression experiment, monitored using a time-lapse ultrasonic tomography method, was carried out and reproduced by the numerical model. Using this combination of technologies, the entire deformation and failure processes were studied at macroscopic and microscopic scales. The results not only illustrated the rock failure and seismic behaviours at different stress levels, but also suggested several precursory behaviours indicating the catastrophic failure of the rock. Secondly, rotary shear experiments were conducted using a newly developed rock physics experimental apparatus ERDmu-T) that was paired with X-ray micro-computed tomography (muCT). This combination of technologies has significant advantages

  17. 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

  18. Bubble formed as a result of a Zeolite Crystal Growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-12-14

    ISS006-E-08835 (14 December 2002) --- View of a bubble formed as a result of a Zeolite Crystal Growth (ZCG) experiment in the Destiny laboratory on the International Space Station (ISS). Expedition Six Commander Kenneth D. Bowersox used a Space Station drill to mix 12 Zeolite samples in clear tubes. Scientists on the ground watching on TV noticed bubbles in the samples. Bowersox used a modified mixing procedure to process autoclaves to isolate bubbles. He re-inserted the samples in the ZCG furnace in Express Rack 2 in the U.S. laboratory/Destiny. This experiment has shown that the bubbles could cause larger number of smaller deformed crystals to grow. Bowersox rotated the samples so that the heavier fluid was thrown to the outside while the lighter bubbles stayed on the inside.

  19. Bubble formed as a result of a Zeolite Crystal Growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-12-14

    ISS006-E-08778 (14 December 2002) --- View of a bubble formed as a result of a Zeolite Crystal Growth (ZCG) experiment in the Destiny laboratory on the International Space Station (ISS). Expedition Six Commander Kenneth D. Bowersox used a Space Station drill to mix 12 Zeolite samples in clear tubes. Scientists on the ground watching on TV noticed bubbles in the samples. Bowersox used a modified mixing procedure to process autoclaves to isolate bubbles. He re-inserted the samples in the ZCG furnace in Express Rack 2 in the U.S. laboratory/Destiny. This experiment has shown that the bubbles could cause larger number of smaller deformed crystals to grow. Bowersox rotated the samples so that the heavier fluid was thrown to the outside while the lighter bubbles stayed on the inside.

  20. Bubble formed as a result of a Zeolite Crystal Growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-12-14

    ISS006-E-08775 (14 December 2002) --- View of a bubble formed as a result of a Zeolite Crystal Growth (ZCG) experiment in the Destiny laboratory on the International Space Station (ISS). Expedition Six Commander Kenneth D. Bowersox used a Space Station drill to mix 12 Zeolite samples in clear tubes. Scientists on the ground watching on TV noticed bubbles in the samples. Bowersox used a modified mixing procedure to process autoclaves to isolate bubbles. He re-inserted the samples in the ZCG furnace in Express Rack 2 in the U.S. laboratory/Destiny. This experiment has shown that the bubbles could cause larger number of smaller deformed crystals to grow. Bowersox rotated the samples so that the heavier fluid was thrown to the outside while the lighter bubbles stayed on the inside.

  1. Bubble formed as a result of a Zeolite Crystal Growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-12-14

    ISS006-E-08773 (14 December 2002) --- View of a bubble formed as a result of a Zeolite Crystal Growth (ZCG) experiment in the Destiny laboratory on the International Space Station (ISS). Expedition Six Commander Kenneth D. Bowersox used a Space Station drill to mix 12 Zeolite samples in clear tubes. Scientists on the ground watching on TV noticed bubbles in the samples. Bowersox used a modified mixing procedure to process autoclaves to isolate bubbles. He re-inserted the samples in the ZCG furnace in Express Rack 2 in the U.S. laboratory/Destiny. This experiment has shown that the bubbles could cause larger number of smaller deformed crystals to grow. Bowersox rotated the samples so that the heavier fluid was thrown to the outside while the lighter bubbles stayed on the inside.

  2. Bubble formed as a result of a Zeolite Crystal Growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-12-14

    ISS006-E-08822 (14 December 2002) --- View of a bubble formed as a result of a Zeolite Crystal Growth (ZCG) experiment in the Destiny laboratory on the International Space Station (ISS). Expedition Six Commander Kenneth D. Bowersox used a Space Station drill to mix 12 Zeolite samples in clear tubes. Scientists on the ground watching on TV noticed bubbles in the samples. Bowersox used a modified mixing procedure to process autoclaves to isolate bubbles. He re-inserted the samples in the ZCG furnace in Express Rack 2 in the U.S. laboratory/Destiny. This experiment has shown that the bubbles could cause larger number of smaller deformed crystals to grow. Bowersox rotated the samples so that the heavier fluid was thrown to the outside while the lighter bubbles stayed on the inside.

  3. Bubble formed as a result of a Zeolite Crystal Growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-12-14

    ISS006-E-08831 (14 December 2002) --- View of a bubble formed as a result of a Zeolite Crystal Growth (ZCG) experiment in the Destiny laboratory on the International Space Station (ISS). Expedition Six Commander Kenneth D. Bowersox used a Space Station drill to mix 12 Zeolite samples in clear tubes. Scientists on the ground watching on TV noticed bubbles in the samples. Bowersox used a modified mixing procedure to process autoclaves to isolate bubbles. He re-inserted the samples in the ZCG furnace in Express Rack 2 in the U.S. laboratory/Destiny. This experiment has shown that the bubbles could cause larger number of smaller deformed crystals to grow. Bowersox rotated the samples so that the heavier fluid was thrown to the outside while the lighter bubbles stayed on the inside.

  4. Bubble formed as a result of a Zeolite Crystal Growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-12-14

    ISS006-E-08805 (14 December 2002) --- View of a bubble formed as a result of a Zeolite Crystal Growth (ZCG) experiment in the Destiny laboratory on the International Space Station (ISS). Expedition Six Commander Kenneth D. Bowersox used a Space Station drill to mix 12 Zeolite samples in clear tubes. Scientists on the ground watching on TV noticed bubbles in the samples. Bowersox used a modified mixing procedure to process autoclaves to isolate bubbles. He re-inserted the samples in the ZCG furnace in Express Rack 2 in the U.S. laboratory/Destiny. This experiment has shown that the bubbles could cause larger number of smaller deformed crystals to grow. Bowersox rotated the samples so that the heavier fluid was thrown to the outside while the lighter bubbles stayed on the inside.

  5. Bubble formed as a result of a Zeolite Crystal Growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-12-14

    ISS006-E-08784 (14 December 2002) --- View of a bubble formed as a result of a Zeolite Crystal Growth (ZCG) experiment in the Destiny laboratory on the International Space Station (ISS). Expedition Six Commander Kenneth D. Bowersox used a Space Station drill to mix 12 Zeolite samples in clear tubes. Scientists on the ground watching on TV noticed bubbles in the samples. Bowersox used a modified mixing procedure to process autoclaves to isolate bubbles. He re-inserted the samples in the ZCG furnace in Express Rack 2 in the U.S. laboratory/Destiny. This experiment has shown that the bubbles could cause larger number of smaller deformed crystals to grow. Bowersox rotated the samples so that the heavier fluid was thrown to the outside while the lighter bubbles stayed on the inside.

  6. Bubble formed as a result of a Zeolite Crystal Growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-12-14

    ISS006-E-08836 (14 December 2002) --- View of a bubble formed as a result of a Zeolite Crystal Growth (ZCG) experiment in the Destiny laboratory on the International Space Station (ISS). Expedition Six Commander Kenneth D. Bowersox used a Space Station drill to mix 12 Zeolite samples in clear tubes. Scientists on the ground watching on TV noticed bubbles in the samples. Bowersox used a modified mixing procedure to process autoclaves to isolate bubbles. He re-inserted the samples in the ZCG furnace in Express Rack 2 in the U.S. laboratory/Destiny. This experiment has shown that the bubbles could cause larger number of smaller deformed crystals to grow. Bowersox rotated the samples so that the heavier fluid was thrown to the outside while the lighter bubbles stayed on the inside.

  7. Bubble formed as a result of a Zeolite Crystal Growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-12-14

    ISS006-E-08799 (14 December 2002) --- View of a bubble formed as a result of a Zeolite Crystal Growth (ZCG) experiment in the Destiny laboratory on the International Space Station (ISS). Expedition Six Commander Kenneth D. Bowersox used a Space Station drill to mix 12 Zeolite samples in clear tubes. Scientists on the ground watching on TV noticed bubbles in the samples. Bowersox used a modified mixing procedure to process autoclaves to isolate bubbles. He re-inserted the samples in the ZCG furnace in Express Rack 2 in the U.S. laboratory/Destiny. This experiment has shown that the bubbles could cause larger number of smaller deformed crystals to grow. Bowersox rotated the samples so that the heavier fluid was thrown to the outside while the lighter bubbles stayed on the inside.

  8. Evaluation of cage designs and feeding regimes for honey bee (Hymenoptera: Apidae) laboratory experiments.

    PubMed

    Huang, Shao Kang; Csaki, Tamas; Doublet, Vincent; Dussaubat, Claudia; Evans, Jay D; Gajda, Anna M; Gregorc, Alex; Hamilton, Michele C; Kamler, Martin; Lecocq, Antoine; Muz, Mustafa N; Neumann, Peter; Ozkirim, Asli; Schiesser, Aygün; Sohr, Alex R; Tanner, Gina; Tozkar, Cansu Ozge; Williams, Geoffrey R; Wu, Lyman; Zheng, Huoqing; Chen, Yan Ping

    2014-02-01

    The aim of this study was to improve cage systems for maintaining adult honey bee (Apis mellifera L.) workers under in vitro laboratory conditions. To achieve this goal, we experimentally evaluated the impact of different cages, developed by scientists of the international research network COLOSS (Prevention of honey bee COlony LOSSes), on the physiology and survival of honey bees. We identified three cages that promoted good survival of honey bees. The bees from cages that exhibited greater survival had relatively lower titers of deformed wing virus, suggesting that deformed wing virus is a significant marker reflecting stress level and health status of the host. We also determined that a leak- and drip-proof feeder was an integral part of a cage system and a feeder modified from a 20-ml plastic syringe displayed the best result in providing steady food supply to bees. Finally, we also demonstrated that the addition of protein to the bees' diet could significantly increase the level ofvitellogenin gene expression and improve bees' survival. This international collaborative study represents a critical step toward improvement of cage designs and feeding regimes for honey bee laboratory experiments.

  9. High-pressure, High-temperature Deformation Experiment Using the New Generation Griggs-type Apparatus

    PubMed Central

    Précigout, Jacques; Stünitz, Holger; Pinquier, Yves; Champallier, Rémi; Schubnel, Alexandre

    2018-01-01

    In order to address geological processes at great depths, rock deformation should ideally be tested at high pressure (> 0.5 GPa) and high temperature (> 300 °C). However, because of the low stress resolution of current solid-pressure-medium apparatuses, high-resolution measurements are today restricted to low-pressure deformation experiments in the gas-pressure-medium apparatus. A new generation of solid-medium piston-cylinder ("Griggs-type") apparatus is here described. Able to perform high-pressure deformation experiments up to 5 GPa and designed to adapt an internal load cell, such a new apparatus offers the potential to establish a technological basis for high-pressure rheology. This paper provides video-based detailed documentation of the procedure (using the "conventional" solid-salt assembly) to perform high-pressure, high-temperature experiments with the newly designed Griggs-type apparatus. A representative result of a Carrara marble sample deformed at 700 °C, 1.5 GPa and 10-5 s-1 with the new press is also given. The related stress-time curve illustrates all steps of a Griggs-type experiment, from increasing pressure and temperature to sample quenching when deformation is stopped. Together with future developments, the critical steps and limitations of the Griggs apparatus are then discussed. PMID:29683444

  10. Helium release during shale deformation: Experimental validation

    DOE PAGES

    Bauer, Stephen J.; Gardner, W. Payton; Heath, Jason E.

    2016-07-01

    This paper describes initial experimental results of helium tracer release monitoring during deformation of shale. Naturally occurring radiogenic 4He is present in high concentration in most shales. During rock deformation, accumulated helium could be released as fractures are created and new transport pathways are created. We present the results of an experimental study in which confined reservoir shale samples, cored parallel and perpendicular to bedding, which were initially saturated with helium to simulate reservoir conditions, are subjected to triaxial compressive deformation. During the deformation experiment, differential stress, axial, and radial strains are systematically tracked. Release of helium is dynamically measuredmore » using a helium mass spectrometer leak detector. Helium released during deformation is observable at the laboratory scale and the release is tightly coupled to the shale deformation. These first measurements of dynamic helium release from rocks undergoing deformation show that helium provides information on the evolution of microstructure as a function of changes in stress and strain.« less

  11. Rheological properties of bridgmanite based on deformation experiments

    NASA Astrophysics Data System (ADS)

    Tsujino, N.; Yamazaki, D.; Yoshino, T.; Sakurai, M.; Higo, Y.; Tange, Y.

    2017-12-01

    The lower mantle occupies 65% of Earth's mantle. Therefore, rheology of the Earth's lower mantle is most important to understand dynamic processes in the Earth's mantle. In Tsujino et al. (2016), we developed deformation experimental technique using D-DIA apparatus as Kawai-type (6-8 type). Crystallographic-preferred-orientation (CPO) of bridgmanite at top of the Earth's lower mantle conditions was determined by shear deformation experiments under upper most lower mantle conditions (25 GPa and 1873 K). The observed seismic shear wave anisotropies near several subducted slabs (Tonga-Kermadec, Kurile, Peru and Java) can be explained in terms of the CPO of bridgmanite as induced by mantle flow parallel to the direction of subduction. On the other hands, one dimensional viscosity models of the Earth's mantle were proposed by geophysical observations while there are large inconsistencies of viscosity (2 3 order magnitude) in the lower mantle between suggested models. It is important to determine viscosity of lower mantle minerals by high pressure experiments in order to understand mantle dynamics. In this study, we conducted in-situ stress-strain measurements of MgSiO3-bridgmanite aggregate at 1473-1673 K and 24 GPa using D-DIA type apparatus as Kawai-type at Spring-8 BL04B1. Measured uniaxial stress, strain rate of bridgmanite during deformation experiments were 0.3-1.3 GPa and 4×10-6 - 3×10-5 /s with <6% strain. Creep strength of bridgmanite at 1×10-5 /s is largest in the mantle minerals and 0.5-1 order magnitude larger than those of transition minerals when only the results using D-DIA apparatus are compared.

  12. Extracting Cell Stiffness from Real-Time Deformability Cytometry: Theory and Experiment

    PubMed Central

    Mietke, Alexander; Otto, Oliver; Girardo, Salvatore; Rosendahl, Philipp; Taubenberger, Anna; Golfier, Stefan; Ulbricht, Elke; Aland, Sebastian; Guck, Jochen; Fischer-Friedrich, Elisabeth

    2015-01-01

    Cell stiffness is a sensitive indicator of physiological and pathological changes in cells, with many potential applications in biology and medicine. A new method, real-time deformability cytometry, probes cell stiffness at high throughput by exposing cells to a shear flow in a microfluidic channel, allowing for mechanical phenotyping based on single-cell deformability. However, observed deformations of cells in the channel not only are determined by cell stiffness, but also depend on cell size relative to channel size. Here, we disentangle mutual contributions of cell size and cell stiffness to cell deformation by a theoretical analysis in terms of hydrodynamics and linear elasticity theory. Performing real-time deformability cytometry experiments on both model spheres of known elasticity and biological cells, we demonstrate that our analytical model not only predicts deformed shapes inside the channel but also allows for quantification of cell mechanical parameters. Thereby, fast and quantitative mechanical sampling of large cell populations becomes feasible. PMID:26588562

  13. Laboratory Studies of High Temperature Deformation and Fracture of Lava Domes

    NASA Astrophysics Data System (ADS)

    Smith, R.; Sammonds, P.; Tuffen, H.; Meredith, P.

    2007-12-01

    The high temperature fracture mechanics of magma at high temperatures exerts a fundamental control on the stability of lava domes and the timing and style of eruptions at andesitic to dacitic volcanoes. This is evidenced in the pervasive fracturing seen in both ancient and active magma conduits and lava domes; in addition to the volcanic earthquakes that occur before and during episodes of dome growth and dome collapse. Uniaxial and triaxial deformation experiments have been performed on crystal rich and crystal free magmas (andesite from Ancestral Mount Shasta, California, USA and a rhyolitic obsidian from Krafla, Iceland) at a range of temperatures (up to 900°C), confining pressures (up to 50 MPa) and strain rates (10-5s-1) to 10-3s-1) whilst recording acoustic emissions (AE). Results from these experiments provide useful inputs into models of lava dome stability, extrusion mechanisms, and source mechanisms for volcanic earthquakes. However, the large sample sizes used to ensure valid results (25mm diameter and 75mm length) made it difficult to maintain stable high temperatures under confined conditions. Also, only rudimentary AE data could be obtained, due to the distance of the transducers from the samples to keep them away from the high temperatures. Here, we present modifications to this apparatus, which include a new furnace, improved loading system, additional pore pressure and permeability measurement capability, and vastly improved acoustic monitoring. This allows (1)stable higher temperatures (up to 1000°C) to be achieved under confined conditions, (2) high temperature and moderate pressure (up to 70 MPa) hydrostatic measurements of permeability and acoustic velocities, (3) high temperature triaxial deformation under different pore fluid and pressure conditions, and (4) full waveform AE monitoring for all deformation experiments. This system can thus be used to measure the physical properties and strength of rocks under volcanic conditions and to

  14. Extracting Cell Stiffness from Real-Time Deformability Cytometry: Theory and Experiment.

    PubMed

    Mietke, Alexander; Otto, Oliver; Girardo, Salvatore; Rosendahl, Philipp; Taubenberger, Anna; Golfier, Stefan; Ulbricht, Elke; Aland, Sebastian; Guck, Jochen; Fischer-Friedrich, Elisabeth

    2015-11-17

    Cell stiffness is a sensitive indicator of physiological and pathological changes in cells, with many potential applications in biology and medicine. A new method, real-time deformability cytometry, probes cell stiffness at high throughput by exposing cells to a shear flow in a microfluidic channel, allowing for mechanical phenotyping based on single-cell deformability. However, observed deformations of cells in the channel not only are determined by cell stiffness, but also depend on cell size relative to channel size. Here, we disentangle mutual contributions of cell size and cell stiffness to cell deformation by a theoretical analysis in terms of hydrodynamics and linear elasticity theory. Performing real-time deformability cytometry experiments on both model spheres of known elasticity and biological cells, we demonstrate that our analytical model not only predicts deformed shapes inside the channel but also allows for quantification of cell mechanical parameters. Thereby, fast and quantitative mechanical sampling of large cell populations becomes feasible. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Evaluation of in-situ deformation experiments of TRIP steel

    NASA Astrophysics Data System (ADS)

    Procházka, J.; Kučerová, L.; Bystrianský, M.

    2017-02-01

    The paper reports on the behaviour of low alloyed TRIP (transformation induced plasticity) steel with Niobium during tensile test. The structures were analysed using in-situ tensile testing coupled with electron backscattering diffraction (EBSD) analysis carried out in scanning electron microscope (SEM). Steel specimens were of same chemical composition; however three different annealing temperatures, 800 °C, 850 °C and 950 °C, were applied to the material during the heat treatment. The treatment consisted of annealing for 20 minutes in the furnace; cooling in salt bath after the heating and holding at 425 °C for 20 minutes for all the samples. Untreated bar was used as reference material. Flat samples for deformation stage were cut out of the heat-treated bars. In situ documentation of microstructure and crystallography development were carried out during the deformation experiments. High deformation lead to significant degradation of EBSD signal.

  16. Constraints on the rheology of the partially molten mantle from numerical models of laboratory experiments

    NASA Astrophysics Data System (ADS)

    Rudge, J. F.; Alisic Jewell, L.; Rhebergen, S.; Katz, R. F.; Wells, G. N.

    2015-12-01

    One of the fundamental components in any dynamical model of melt transport is the rheology of partially molten rock. This rheology is poorly understood, and one way in which a better understanding can be obtained is by comparing the results of laboratory deformation experiments to numerical models. Here we present a comparison between numerical models and the laboratory setup of Qi et al. 2013 (EPSL), where a cylinder of partially molten rock containing rigid spherical inclusions was placed under torsion. We have replicated this setup in a finite element model which solves the partial differential equations describing the mechanical process of compaction. These computationally-demanding 3D simulations are only possible due to the recent development of a new preconditioning method for the equations of magma dynamics. The experiments show a distinct pattern of melt-rich and melt-depleted regions around the inclusions. In our numerical models, the pattern of melt varies with key rheological parameters, such as the ratio of bulk to shear viscosity, and the porosity- and strain-rate-dependence of the shear viscosity. These observed melt patterns therefore have the potential to constrain rheological properties. While there are many similarities between the experiments and the numerical models, there are also important differences, which highlight the need for better models of the physics of two-phase mantle/magma dynamics. In particular, the laboratory experiments display more pervasive melt-rich bands than is seen in our numerics.

  17. 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.

  18. Real-time noble gas release signaling rock deformation

    NASA Astrophysics Data System (ADS)

    Bauer, S. J.; Gardner, W. P.; Lee, H.

    2016-12-01

    We present empirical results/relationships of rock strain, microfracture density, acoustic emissions, and noble gas release from laboratory triaxial experiments for a granite and basalt. Noble gases are contained in most crustal rock at inter/intra granular sites, their release during natural and manmade stress and strain changes represents a signal of brittle/semi brittle deformation. The gas composition depends on lithology, geologic history and age, fluids present, and uranium, thorium and potassium-40 concentrations in the rocks that affect radiogenic noble gases (helium, argon) production. Noble gas emission and its relationship to crustal processes have been studied, including correlations to tectonic velocities and qualitative estimates of deep permeability from surface measurements, finger prints of nuclear weapon detonation, and as potential precursory signals to earthquakes attributed to gas release due to pre-seismic stress, dilatancy and/or rock fracturing. Helium emission has been shown as a precursor of volcanic activity. Real-time noble gas release is observed using an experimental system utilizing mass spectrometers to measure gases released during triaxial rock deformation. Noble gas release is shown to represent a sensitive precursor signal of rock deformation by relating real-time noble gas release to stress-strain state changes and acoustic emissions. We propose using noble gas release to also signal rock deformation in boreholes, mines and nuclear waste repositories. We postulate each rock exhibits a gas release signature which is microstructure, stress/strain state, and or permanent deformation dependent. Such relationships, when calibrated, may be used to sense rock deformation and then develop predictive models. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corp., for the US Dept. of Energy's National Nuclear Security Administration under

  19. Laboratory Investigation of Coal Deformation Behavior and Its Influence on Permeability Evolution During Methane Displacement by CO2

    NASA Astrophysics Data System (ADS)

    Fan, Jingjing; Feng, Ruimin; Wang, Jin; Wang, Yanbin

    2017-07-01

    Geological sequestration of CO2 in coal seams is of significant interest to both academia and industry. A thorough laboratory investigation of mechanical and flow behaviors is crucial for understanding the complex response of coalbeds to CO2 injection-enhanced coalbed methane recovery (CO2-ECBM) operation. In this work, systematic experiments were carried out on cylindrical coal core specimens under different uniform confining stresses. The coal deformation caused by variations in effective stress as well as the sorption-induced matrix swelling/shrinkage was monitored. The competitive gas sorption characteristics and permeability evolution during the process of methane displacement by CO2 were also investigated. The measured volumetric strain results indicate that sorption-induced strain is the dominant factor in the coal deformation. The relationship between the volumetric strain and the adsorbed gas volume has been revealed to be a linear function. Experimental results obtained under different stress conditions suggest that higher confining stress suppresses the increase in both volumetric strain and the adsorbed gas volume. Furthermore, both methane displacement and CO2 injection are reduced when applying higher confining stresses. In addition, the permeability enhancement is heavily suppressed at higher confining stress. At a certain confining stress, a characteristic "U-shaped" trend of permeability is presented as a function of decreasing pore pressure. This study contributes to the understanding of coal deformation and its impact on permeability evolution under uniformly stressed condition, which has practical significance for CO2 sequestration and CO2-ECBM operation in the Qinshui basin.

  20. 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…

  1. Large poroelastic deformation of a soft material

    NASA Astrophysics Data System (ADS)

    MacMinn, Christopher W.; Dufresne, Eric R.; Wettlaufer, John S.

    2014-11-01

    Flow through a porous material will drive mechanical deformation when the fluid pressure becomes comparable to the stiffness of the solid skeleton. This has applications ranging from hydraulic fracture for recovery of shale gas, where fluid is injected at high pressure, to the mechanics of biological cells and tissues, where the solid skeleton is very soft. The traditional linear theory of poroelasticity captures this fluid-solid coupling by combining Darcy's law with linear elasticity. However, linear elasticity is only volume-conservative to first order in the strain, which can become problematic when damage, plasticity, or extreme softness lead to large deformations. Here, we compare the predictions of linear poroelasticity with those of a large-deformation framework in the context of two model problems. We show that errors in volume conservation are compounded and amplified by coupling with the fluid flow, and can become important even when the deformation is small. We also illustrate these results with a laboratory experiment.

  2. 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…

  3. Constrains on the Rheology of the Lithosphere Inferred from Nano-Forsterite Deformation Experiments

    NASA Astrophysics Data System (ADS)

    Gasc, J.; Demouchy, S. A.; Barou, F.; Koizumi, S.

    2017-12-01

    The rheology of the lithospheric mantle is usually inferred from experiments performed at temperatures and strain rates greater than in the Earth. In these conditions, deformation occurs via dislocation creep and the flow laws obtained experimentally are then extrapolated to natural conditions. Despite the difficulty of achieving steady-state flow at low temperatures (<1200°C), recent studies have shown that low-temperature deformation of olivine implies different deformation mechanisms and that rotational defects, i.e. disclinations, might be involved in the low-temperature rheology of the mantle. To help constrain the rheology of the upper mantle and address the role of the various defects at play at the microscopic scale, we used a high-pressure high-temperature gas medium deformation apparatus (aka. Paterson press) to deform pre-sintered nano-forsterite aggregates. The fine-grained nature of the samples allows us to probe the deformation mechanisms at play when dislocation creep is limited. Experiments were performed at 300 MPa, 900-1200°C, and constant displacement yielding strain rates around 10-5 s-1. The samples were analyzed using state-of-the-art microscopy techniques. EBSD analysis did not reveal crystal preferred orientation. However, grain plasticity was evidenced and takes place almost exclusively via subgrain formation with rotation around the c-axis, a condition that does not allow sustainable plastic flow. Further investigations are ongoing to identify if other defects, such as disclinations are present. Grain rotation was also evidenced by a shape preferred orientation. Regardless of the mechanisms involved, rheology data show that the samples are stronger (from 0.5-2 GPa) than their iron-bearing olivine counterparts, due to a combined effect of grain size and composition (Fe has a softening effect on olivine). The temperature dependence is weaker than predicted by high temperature data in the dislocation creep regime, but remains greater than

  4. 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)

  5. Monitoring Building Deformation with InSAR: Experiments and Validation.

    PubMed

    Yang, Kui; Yan, Li; Huang, Guoman; Chen, Chu; Wu, Zhengpeng

    2016-12-20

    Synthetic Aperture Radar Interferometry (InSAR) techniques are increasingly applied for monitoring land subsidence. The advantages of InSAR include high accuracy and the ability to cover large areas; nevertheless, research validating the use of InSAR on building deformation is limited. In this paper, we test the monitoring capability of the InSAR in experiments using two landmark buildings; the Bohai Building and the China Theater, located in Tianjin, China. They were selected as real examples to compare InSAR and leveling approaches for building deformation. Ten TerraSAR-X images spanning half a year were used in Permanent Scatterer InSAR processing. These extracted InSAR results were processed considering the diversity in both direction and spatial distribution, and were compared with true leveling values in both Ordinary Least Squares (OLS) regression and measurement of error analyses. The detailed experimental results for the Bohai Building and the China Theater showed a high correlation between InSAR results and the leveling values. At the same time, the two Root Mean Square Error (RMSE) indexes had values of approximately 1 mm. These analyses show that a millimeter level of accuracy can be achieved by means of InSAR technique when measuring building deformation. We discuss the differences in accuracy between OLS regression and measurement of error analyses, and compare the accuracy index of leveling in order to propose InSAR accuracy levels appropriate for monitoring buildings deformation. After assessing the advantages and limitations of InSAR techniques in monitoring buildings, further applications are evaluated.

  6. Monitoring Building Deformation with InSAR: Experiments and Validation

    PubMed Central

    Yang, Kui; Yan, Li; Huang, Guoman; Chen, Chu; Wu, Zhengpeng

    2016-01-01

    Synthetic Aperture Radar Interferometry (InSAR) techniques are increasingly applied for monitoring land subsidence. The advantages of InSAR include high accuracy and the ability to cover large areas; nevertheless, research validating the use of InSAR on building deformation is limited. In this paper, we test the monitoring capability of the InSAR in experiments using two landmark buildings; the Bohai Building and the China Theater, located in Tianjin, China. They were selected as real examples to compare InSAR and leveling approaches for building deformation. Ten TerraSAR-X images spanning half a year were used in Permanent Scatterer InSAR processing. These extracted InSAR results were processed considering the diversity in both direction and spatial distribution, and were compared with true leveling values in both Ordinary Least Squares (OLS) regression and measurement of error analyses. The detailed experimental results for the Bohai Building and the China Theater showed a high correlation between InSAR results and the leveling values. At the same time, the two Root Mean Square Error (RMSE) indexes had values of approximately 1 mm. These analyses show that a millimeter level of accuracy can be achieved by means of InSAR technique when measuring building deformation. We discuss the differences in accuracy between OLS regression and measurement of error analyses, and compare the accuracy index of leveling in order to propose InSAR accuracy levels appropriate for monitoring buildings deformation. After assessing the advantages and limitations of InSAR techniques in monitoring buildings, further applications are evaluated. PMID:27999403

  7. 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?

  8. Making Sparklers: An Introductory Laboratory Experiment

    NASA Astrophysics Data System (ADS)

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

    1995-07-01

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

  9. Testing Plastic Deformations of Materials in the Introductory Undergraduate Mechanics Laboratory

    ERIC Educational Resources Information Center

    Romo-Kroger, C. M.

    2012-01-01

    Normally, a mechanics laboratory at the undergraduate level includes an experiment to verify compliance with Hooke's law in materials, such as a steel spring and an elastic rubber band. Stress-strain curves are found for these elements. Compression in elastic bands is practically impossible to achieve due to flaccidity. A typical experiment for…

  10. 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.

  11. The BDX experiment at Jefferson Laboratory

    NASA Astrophysics Data System (ADS)

    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 trough 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 an 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.

  12. 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.

  13. 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)

  14. Deformation mechanisms and evolution of the microstructure of gouge in the Main Fault in Opalinus Clay in the Mont Terri rock laboratory (CH)

    NASA Astrophysics Data System (ADS)

    Laurich, Ben; Urai, Janos L.; Vollmer, Christian; Nussbaum, Christophe

    2018-01-01

    We studied gouge from an upper-crustal, low-offset reverse fault in slightly overconsolidated claystone in the Mont Terri rock laboratory (Switzerland). The laboratory is designed to evaluate the suitability of the Opalinus Clay formation (OPA) to host a repository for radioactive waste. The gouge occurs in thin bands and lenses in the fault zone; it is darker in color and less fissile than the surrounding rock. It shows a matrix-based, P-foliated microfabric bordered and truncated by micrometer-thin shear zones consisting of aligned clay grains, as shown with broad-ion-beam scanning electron microscopy (BIB-SEM) and optical microscopy. Selected area electron diffraction based on transmission electron microscopy (TEM) shows evidence for randomly oriented nanometer-sized clay particles in the gouge matrix, surrounding larger elongated phyllosilicates with a strict P foliation. For the first time for the OPA, we report the occurrence of amorphous SiO2 grains within the gouge. Gouge has lower SEM-visible porosity and almost no calcite grains compared to the undeformed OPA. We present two hypotheses to explain the origin of gouge in the Main Fault: (i) authigenic generation consisting of fluid-mediated removal of calcite from the deforming OPA during shearing and (ii) clay smear consisting of mechanical smearing of calcite-poor (yet to be identified) source layers into the fault zone. Based on our data we prefer the first or a combination of both, but more work is needed to resolve this. Microstructures indicate a range of deformation mechanisms including solution-precipitation processes and a gouge that is weaker than the OPA because of the lower fraction of hard grains. For gouge, we infer a more rate-dependent frictional rheology than suggested from laboratory experiments on the undeformed OPA.

  15. 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. © 2013 by The International Union of Biochemistry and Molecular Biology.

  16. Experimental deformation of a mafic rock - interplay between fracturing, reaction and viscous deformation

    NASA Astrophysics Data System (ADS)

    Marti, Sina; Stünitz, Holger; Heilbronner, Renée; Plümper, Oliver; Drury, Martyn

    2016-04-01

    Deformation experiments were performed on natural Maryland Diabase (˜ 55% Plg, 42% Px, 3% accessories, 0.18 wt.-% H2O added) in a Griggs-type deformation apparatus in order to explore the brittle-viscous transition and the interplay between deformation and mineral reactions. Shear experiments at strain rates of ˜ 2e-5 /s are performed, at T=600, 700 and 800°C and confining pressures Pc=1.0 and 1.5 GPa. Deformation localizes in all experiments. Below 700°C, the microstructure is dominated by brittle deformation with a foliation formed by cataclastic flow and high strain accommodated along 3-5 major ultracataclasite shear bands. At 700°C, the bulk of the material still exhibits abundant microfractures, however, deformation localizes into an anastomosing network of shear bands (SB) formed from a fine-grained (<< 1 μm) mixture of newly formed Plg and Amph. These reaction products occur almost exclusively along syn-kinematic structures such as fractures and SB. Experiments at 800°C show extensive mineral reactions, with the main reaction products Amph+Plg (+Zo). Deformation is localized in broad C' and C SB formed by a fine-grained (0.1 - 0.8 μm) mixture of Plg+Amph (+Zo). The onset of mineral reactions in the 700°C experiments shows that reaction kinetics and diffusional mass transport are fast enough to keep up with the short experimental timescales. While in the 700°C experiments brittle processes kinematically contribute to deformation, fracturing is largely absent at 800°C. Diffusive mass transfer dominates. The very small grain size within SB favours a grain size sensitive deformation mechanism. Due to the presence of water (and relatively high supported stresses), dissolution-precipitation creep is interpreted to be the dominant strain accommodating mechanism. From the change of Amph coronas around Px clasts with strain, we can determine that Amph is re-dissolved at high stress sites while growing in low stress sites, showing the ability of Amph to

  17. 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.

  18. 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.

  19. 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.

  20. Capturing intraoperative deformations: research experience at Brigham and Women's Hospital.

    PubMed

    Warfield, Simon K; Haker, Steven J; Talos, Ion-Florin; Kemper, Corey A; Weisenfeld, Neil; Mewes, Andrea U J; Goldberg-Zimring, Daniel; Zou, Kelly H; Westin, Carl-Fredrik; Wells, William M; Tempany, Clare M C; Golby, Alexandra; Black, Peter M; Jolesz, Ferenc A; Kikinis, Ron

    2005-04-01

    During neurosurgical procedures the objective of the neurosurgeon is to achieve the resection of as much diseased tissue as possible while achieving the preservation of healthy brain tissue. The restricted capacity of the conventional operating room to enable the surgeon to visualize critical healthy brain structures and tumor margin has lead, over the past decade, to the development of sophisticated intraoperative imaging techniques to enhance visualization. However, both rigid motion due to patient placement and nonrigid deformations occurring as a consequence of the surgical intervention disrupt the correspondence between preoperative data used to plan surgery and the intraoperative configuration of the patient's brain. Similar challenges are faced in other interventional therapies, such as in cryoablation of the liver, or biopsy of the prostate. We have developed algorithms to model the motion of key anatomical structures and system implementations that enable us to estimate the deformation of the critical anatomy from sequences of volumetric images and to prepare updated fused visualizations of preoperative and intraoperative images at a rate compatible with surgical decision making. This paper reviews the experience at Brigham and Women's Hospital through the process of developing and applying novel algorithms for capturing intraoperative deformations in support of image guided therapy.

  1. Proof of concept of a simple computer-assisted technique for correcting bone deformities.

    PubMed

    Ma, Burton; Simpson, Amber L; Ellis, Randy E

    2007-01-01

    We propose a computer-assisted technique for correcting bone deformities using the Ilizarov method. Our technique is an improvement over prior art in that it does not require a tracking system, navigation hardware and software, or intraoperative registration. Instead, we rely on a postoperative CT scan to obtain all of the information necessary to plan the correction and compute a correction schedule for the patient. Our laboratory experiments using plastic phantoms produced deformity corrections accurate to within 3.0 degrees of rotation and 1 mm of lengthening.

  2. 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…

  3. Stresses and pressures at the quartz-to-coesite phase transformation in shear deformation experiments

    NASA Astrophysics Data System (ADS)

    Richter, B.; Stünitz, H.; Heilbronner, R.

    2016-11-01

    Coesite was found in quartz aggregates, experimentally deformed at confining pressures of 1.0-1.5 GPa and temperatures between 600°C and 900°C. The confining pressure (Pc) and, in most cases, the mean stress (σm) of the experiments were below those of the quartz-to-coesite phase transformation. Yet coesite formed when the maximum principal stress (σ1) was within the P-T range of the coesite stability field. In one sample, the euhedral coesite grains were corroded indicating that coesite started to transform back to quartz. It is inferred that this sample started to deform with σ1 above the quartz-to-coesite phase transformation and, with ongoing deformation, σ1 decreased to values in the quartz stability field due to strain weakening. In all cases, σ1 triggered the quartz-to-coesite reaction as well as the reverse reaction, suggesting that σ1 is the critical parameter for the quartz-to-coesite transformation—not Pc or σm. With progressive deformation, the coesite laths rotated toward the shear plane as more rigid particles with the sense of shear. In case of back reaction, new quartz grains exhibit no systematic crystallographic relationship with respect to old coesite. The experiments cover different degrees of pressure "overstepping," different temperatures, and different experimental durations at P and T, and deformation always enhances the reaction kinetics. The observation that σ1 is critical for a pressure-dependent phase transformation (also for reversals) poses questions for the thermodynamic treatment of such phase transformations.

  4. Rate and state dependent processes in sea ice deformation

    NASA Astrophysics Data System (ADS)

    Sammonds, P. R.; Scourfield, S.; Lishman, B.

    2014-12-01

    Realistic models of sea ice processes and properties are needed to assess sea ice thickness, extent and concentration and, when run within GCMs, provide prediction of climate change. The deformation of sea ice is a key control on the Arctic Ocean dynamics. But the deformation of sea ice is dependent not only on the rate of the processes involved but also the state of the sea ice and particular in terms of its evolution with time and temperature. Shear deformation is a dominant mechanism from the scale of basin-scale shear lineaments, through floe-floe interaction to block sliding in ice ridges. The shear deformation will not only depend on the speed of movement of ice surfaces but also the degree that the surfaces have bonded during thermal consolidation and compaction. Frictional resistance to sliding can vary by more than two orders of magnitude depending on the state of the interface. But this in turn is dependent upon both imposed conditions and sea ice properties such as size distribution of interfacial broken ice, angularity, porosity, salinity, etc. We review experimental results in sea ice mechanics from mid-scale experiments, conducted in the Hamburg model ship ice tank, simulating sea ice floe motion and interaction and compare these with laboratory experiments on ice friction done in direct shear from which a rate and state constitutive relation for shear deformation is derived. Finally we apply this to field measurement of sea ice friction made during experiments in the Barents Sea to assess the other environmental factors, the state terms, that need to be modelled in order to up-scale to Arctic Ocean-scale dynamics.

  5. 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

  6. 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.

  7. Circular dichroism spectroscopy: Enhancing a traditional undergraduate biochemistry laboratory experience.

    PubMed

    Lewis, Russell L; Seal, Erin L; Lorts, Aimee R; Stewart, Amanda L

    2017-11-01

    The undergraduate biochemistry laboratory curriculum is designed to provide students with experience in protein isolation and purification protocols as well as various data analysis techniques, which enhance the biochemistry lecture course and give students a broad range of tools upon which to build in graduate level laboratories or once they begin their careers. One of the most common biochemistry protein purification experiments is the isolation and characterization of cytochrome c. Students across the country purify cytochrome c, lysozyme, or some other well-known protein to learn these common purification techniques. What this series of experiments lacks is the use of sophisticated instrumentation that is rarely available to undergraduate students. To give students a broader background in biochemical spectroscopy techniques, a new circular dichroism (CD) laboratory experiment was introduced into the biochemistry laboratory curriculum. This CD experiment provides students with a means of conceptualizing the secondary structure of their purified protein, and assessments indicate that students' understanding of the technique increased significantly. Students conducted this experiment with ease and in a short time frame, so this laboratory is conducive to merging with other data analysis techniques within a single laboratory period. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(6):515-520, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

  8. 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.

  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. Development of Accessible Laboratory Experiments for Students with Visual Impairments

    ERIC Educational Resources Information Center

    Kroes, KC; Lefler, Daniel; Schmitt, Aaron; Supalo, Cary A.

    2016-01-01

    The hands-on laboratory experiments are frequently what spark students' interest in science. Students who are blind or have low vision (BLV) typically do not get the same experience while participating in hands-on activities due to accessibility. Over the course of approximately nine months, common chemistry laboratory experiments were adapted and…

  11. Deformation mechanisms of nanotwinned Al

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Xinghang

    The objective of this project is to investigate the role of different types of layer interfaces on the formation of high density stacking fault (SF) in Al in Al/fcc multilayers, and understand the corresponding deformation mechanisms of the films. Stacking faults or twins can be intentionally introduced (via growth) into certain fcc metals with low stacking fault energy (such as Cu, Ag and 330 stainless steels) to achieve high strength, high ductility, superior thermal stability and good electrical conductivity. However it is still a major challenge to synthesize these types of defects into metals with high stacking fault energy, suchmore » as Al. Although deformation twins have been observed in some nanocrystalline Al powders by low temperature, high strain rate cryomilling or in Al at the edge of crack tip or indentation (with the assistance of high stress intensity factor), these deformation techniques typically introduce twins sporadically and the control of deformation twin density in Al is still not feasible. This project is designed to test the following hypotheses: (1) Certain type of layer interfaces may assist the formation of SF in Al, (2) Al with high density SF may have deformation mechanisms drastically different from those of coarse-grained Al and nanotwinned Cu. To test these hypotheses, we have performed the following tasks: (i) Investigate the influence of layer interfaces, stresses and deposition parameters on the formation and density of SF in Al. (ii) Understand the role of SF on the deformation behavior of Al. In situ nanoindentation experiments will be performed to probe deformation mechanisms in Al. The major findings related to the formation mechanism of twins and mechanical behavior of nanotwinned metals include the followings: 1) Our studies show that nanotwins can be introduced into metals with high stacking fault energy, in drastic contrast to the general anticipation. 2) We show two strategies that can effectively introduce growth

  12. 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.

  13. An experimental approach to non - extensive statistical physics and Epidemic Type Aftershock Sequence (ETAS) modeling. The case of triaxially deformed sandstones using acoustic emissions.

    NASA Astrophysics Data System (ADS)

    Stavrianaki, K.; Vallianatos, F.; Sammonds, P. R.; Ross, G. J.

    2014-12-01

    Fracturing is the most prevalent deformation mechanism in rocks deformed in the laboratory under simulated upper crustal conditions. Fracturing produces acoustic emissions (AE) at the laboratory scale and earthquakes on a crustal scale. The AE technique provides a means to analyse microcracking activity inside the rock volume and since experiments can be performed under confining pressure to simulate depth of burial, AE can be used as a proxy for natural processes such as earthquakes. Experimental rock deformation provides us with several ways to investigate time-dependent brittle deformation. Two main types of experiments can be distinguished: (1) "constant strain rate" experiments in which stress varies as a result of deformation, and (2) "creep" experiments in which deformation and deformation rate vary over time as a result of an imposed constant stress. We conducted constant strain rate experiments on air-dried Darley Dale sandstone samples in a variety of confining pressures (30MPa, 50MPa, 80MPa) and in water saturated samples with 20 MPa initial pore fluid pressure. The results from these experiments used to determine the initial loading in the creep experiments. Non-extensive statistical physics approach was applied to the AE data in order to investigate the spatio-temporal pattern of cracks close to failure. A more detailed study was performed for the data from the creep experiments. When axial stress is plotted against time we obtain the trimodal creep curve. Calculation of Tsallis entropic index q is performed to each stage of the curve and the results are compared with the ones from the constant strain rate experiments. The Epidemic Type Aftershock Sequence model (ETAS) is also applied to each stage of the creep curve and the ETAS parameters are calculated. We investigate whether these parameters are constant across all stages of the curve, or whether there are interesting patterns of variation. This research has been co-funded by the European Union

  14. Thermal Hydraulic Computational Fluid Dynamics Simulations and Experimental Investigation of Deformed Fuel Assemblies

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mays, Brian; Jackson, R. Brian

    2017-03-08

    The project, Toward a Longer Life Core: Thermal Hydraulic CFD Simulations and Experimental Investigation of Deformed Fuel Assemblies, DOE Project code DE-NE0008321, was a verification and validation project for flow and heat transfer through wire wrapped simulated liquid metal fuel assemblies that included both experiments and computational fluid dynamics simulations of those experiments. This project was a two year collaboration between AREVA, TerraPower, Argonne National Laboratory and Texas A&M University. Experiments were performed by AREVA and Texas A&M University. Numerical simulations of these experiments were performed by TerraPower and Argonne National Lab. Project management was performed by AREVA Federal Services.more » The first of a kind project resulted in the production of both local point temperature measurements and local flow mixing experiment data paired with numerical simulation benchmarking of the experiments. The project experiments included the largest wire-wrapped pin assembly Mass Index of Refraction (MIR) experiment in the world, the first known wire-wrapped assembly experiment with deformed duct geometries and the largest numerical simulations ever produced for wire-wrapped bundles.« less

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  16. Influence of the mode of deformation on recrystallisation behaviour of titanium through experiments, mean field theory and phase field model

    NASA Astrophysics Data System (ADS)

    Athreya, C. N.; Mukilventhan, A.; Suwas, Satyam; Vedantam, Srikanth; Subramanya Sarma, V.

    2018-04-01

    The influence of the mode of deformation on recrystallisation behaviour of Ti was studied by experiments and modelling. Ti samples were deformed through torsion and rolling to the same equivalent strain of 0.5. The deformed samples were annealed at different temperatures for different time durations and the recrystallisation kinetics were compared. Recrystallisation is found to be faster in the rolled samples compared to the torsion deformed samples. This is attributed to the differences in stored energy and number of nuclei per unit area in the two modes of deformation. Considering decay in stored energy during recrystallisation, the grain boundary mobility was estimated through a mean field model. The activation energy for recrystallisation obtained from experiments matched with the activation energy for grain boundary migration obtained from mobility calculation. A multi-phase field model (with mobility estimated from the mean field model as a constitutive input) was used to simulate the kinetics, microstructure and texture evolution. The recrystallisation kinetics and grain size distributions obtained from experiments matched reasonably well with the phase field simulations. The recrystallisation texture predicted through phase field simulations compares well with experiments though few additional texture components are present in simulations. This is attributed to the anisotropy in grain boundary mobility, which is not accounted for in the present study.

  17. 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.

  18. 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,…

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wileveau, Yannick; Su, Kun; Ghoreychi, Mehdi

    2007-07-01

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

  20. Water Surface Impact and Ricochet of Deformable Elastomeric Spheres

    NASA Astrophysics Data System (ADS)

    Hurd, Randy C.

    Soft and deformable silicone rubber spheres ricochet from a water surface when rigid spheres and disks (or skipping stones) cannot. This dissertation investigates why these objects are able to skip so successfully. High speed cameras allow us to see that these unique spheres deform significantly as they impact the water surface, flattening into pancake-like shapes with greater area. Though the water entry behavior of deformable spheres deviates from that of rigid spheres, our research shows that if this deformation is accounted for, their behavior can be predicted from previously established methods. Soft spheres skip more easily because they deform significantly when impacting the water surface. We present a diagram which enables the prediction of a ricochet from sphere impact conditions such as speed and angle. Experiments and mathematical representations of the sphere skipping both show that these deformable spheres skip more readily because deformation momentarily increases sphere area and produces an attack angle with the water which is favorable to skipping. Predictions from our mathematical representation of sphere skipping agree strongly with observations from experiments. Even when a sphere was allowed to skip multiple times in the laboratory, the mathematical predictions show good agreement with measured impact conditions through subsequent skipping events. While studying multiple impact events in an outdoor setting, we discovered a previously unidentified means of skipping, which is unique to deformable spheres. This new skipping occurs when a relatively soft sphere first hits the water at a high speed and low impact angle and the sphere begins to rotate very quickly. This quick rotation causes the sphere to stretch into a shape similar to an American football and maintain this shape while it spins. The sphere is observed to move nearly parallel with the water surface with the tips of this "football" dipping into the water as it rotates and the sides

  1. 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.

  2. An Upper Level Laboratory Course of Integrated Experiments

    ERIC Educational Resources Information Center

    Rose, T. L.; Seyse, R. J.

    1974-01-01

    Discusses the development of a one-year laboratory course in an effort to provide a link between traditional laboratories devoted to a single area of chemistry and the total involvement of a single narrow research project. Included are outlines of 32-hour lectures and 11 experiments performed in the integrated course. (CC)

  3. 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,…

  4. 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…

  5. 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…

  6. 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.

  7. Interfacial Bubble Deformations

    NASA Astrophysics Data System (ADS)

    Seymour, Brian; Shabane, Parvis; Cypull, Olivia; Cheng, Shengfeng; Feitosa, Klebert

    Soap bubbles floating at an air-water experience deformations as a result of surface tension and hydrostatic forces. In this experiment, we investigate the nature of such deformations by taking cross-sectional images of bubbles of different volumes. The results show that as their volume increases, bubbles transition from spherical to hemispherical shape. The deformation of the interface also changes with bubble volume with the capillary rise converging to the capillary length as volume increases. The profile of the top and bottom of the bubble and the capillary rise are completely determined by the volume and pressure differences. James Madison University Department of Physics and Astronomy, 4VA Consortium, Research Corporation for Advancement of Science.

  8. Double-Sided Laser Heating in Radial Diffraction Geometry for Diamond Anvil Cell Deformation Experiments at Simultaneous High Pressures and Temperatures

    NASA Astrophysics Data System (ADS)

    Miyagi, L. M.; Kunz, M.; Couper, S.; Lin, F.; Yan, J.; Doran, A.; MacDowell, A. A.

    2017-12-01

    The rheology of rocks and minerals in the Earth's deep interior plays a primary role in controlling large scale geodynamic processes such as mantle convection and slab subduction. Plastic deformation resulting from these processes can lead to texture development and associated seismic anisotropy. If a detailed understanding of the link between deformation and seismic anisotropy is established, observations of seismic anisotropy can be used to understand the dynamic state in the deep Earth. However, performing deformation experiments at lower mantle pressure and temperature conditions are extremely challenging. Thus most deformation studies have been performed either at room temperature and high pressure or at reduced pressures and high temperature. Only a few extraordinary efforts have attained pressures and temperatures relevant to lower mantle. Therefore our ability to interpret observations of lower mantle seismic anisotropy in terms of mantle flow models remains limited. In order to expand the pressure and temperature range available for deformation of deep Earth relevant mineral phases, we have developed a laser heating system for in-situ double-sided heating in radial diffraction geometry at beamline 12.2.2 of the Advanced Light Source of Lawrence Berkeley National Laboratory. This allows texture and lattice strain measurements to be recorded at simultaneous high pressures and temperatures in the diamond anvil cell. This new system is integrated into the newly built axial laser heating system to allow for rapid and reliable transitioning between double-sided laser heating in axial and radial geometries. Transitioning to radial geometry is accomplished by redirecting the laser and imaging paths from 0° and 180° to 90° and 270°. To redirect the 90° path, a motorized periscope mirror pair with an objective lens can be inserted into the downstream axial beam path. The 270° redirection is accomplished by removing the upstream axial objective lens and

  9. 3D Coda Attenuation Tomography of Acoustic Emission Data from Laboratory Samples as a tool for imaging pre-failure deformation mechanisms

    NASA Astrophysics Data System (ADS)

    Vinciguerra, S.; King, T. I.; Benson, P. M.; De Siena, L.

    2017-12-01

    In recent years, 3D and 4D seismic tomography have unraveled medium changes during the seismic cycle or before eruptive events. As our resolving power increases, however, complex structures increasingly affect images. Being able to interpret and understand these features requires a multi-discipline approach combining different methods, each sensitive to particular properties of the sub-surface. Rock deformation laboratory experiments can relate seismic properties to the evolving medium quantitatively. Here, an array of 1 MHz Piezo-Electric Transducers has recorded high-quality low-noise acoustic emission (AE) data during triaxial compressional experiments. Samples of Carrara Marble, Darley Dale Sandstone and Westerly Granite were deformed in saturated conditions representative of a depth of about 1 km until brittle failure. Using a time window around sample failure, AE data were filtered between 5 and 75 KHz and processed using a 3D P-coda attenuation-tomography method. Ratios of P-direct to P-coda energies calculated for each source-receiver path were inverted using the coda normalisation method for values of Q (P-wave quality factor). The results show Q-variation with respect to an average Q. Q is a combination of the effects of scattering attenuation (Qs) and intrinsic attenuation Q (Qi), which can be correlated to the sample structure. Qs primary controls energy dissipation in the presence at acoustic impedance (AI) surfaces and at fracture tips, independently of rock type, while pore fluid effects dissipate energy (Qi). Damaged zones appear as high-Q and low-Q anomalies in unsaturated and saturated samples, respectively. We have attributed frequency-dependent high-Q to resonance in the presence of AI surfaces. Low Q areas appear behind AI surfaces and are interpreted as energy shadows. These shadows can affect attenuation tomography imaging at field scale.

  10. Laboratory reconnection experiments

    NASA Astrophysics Data System (ADS)

    Grulke, Olaf

    Laboratory experiments dedicated for the study of magnetic reconnection have been contributed considerably to a more detailed understanding of the involved processes. Their strength is to disentangle parameter dependencies, to diagnose in detail the plasma and field response, and to form an excellent testbed for the validation of numerical simulations. In the present paper recent results obtained from the new cylindrical reconnection experiment VINETA II are presented. The experimental setup allows to independently vary plasma parameters, reconnection drive strength/timescale, and current sheet amplitude. Current research objectives focus on two major scientific issues: Guide field effects on magnetic reconnection and the evolution of electromagnetic fluctuations. The superimposed homogeneous magnetic guide field has a strong influence on the spatiotemporal evolution of the current sheet, predominantly due to magnetic pitch angle effects, which leads to a strong elongation of the sheet along the separatrices and results in axial gradients of the reconnection rates. Within the current sheet, incoherent electromagnetic fluctuations are observed. Their magnetic signature is characterized by a broad spectrum somewhat centered around the lower-hybrid frequency and extremely short spatial correlation lengths being typically smaller than the local ion sound radius. The fluctuation amplitude correlates with the local current density and, thus, for low guide fields, displays also axial gradients. Despite the quantitatively different parameter regime and geometry the basic fluctuation properties are in good agreement with studies conducted at the MRX experiment (PPPL).

  11. 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

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

    NASA Technical Reports Server (NTRS)

    Vogl, J. L.

    1973-01-01

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

  13. 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

  14. Measurement of rock mass deformation with grouted coaxial antenna cables

    NASA Astrophysics Data System (ADS)

    Dowding, C. H.; Su, M. B.; O'Connor, K.

    1989-01-01

    Techniques presented herein show how reflected voltage pulses from coaxial antenna cable grouted in rock masses can be employed to quantify the type and magnitude of rock mass deformation. This measurement is similar to that obtained from a combined full profile extensometer (to measure local extension) and inclinometer (to measure local shearing). Rock mass movements deform the grouted cable, which locally changes cable capacitance and thereby the reflected wave form of the voltage pulse. Thus, by monitoring changes in these reflection signatures, it is possible to monitor rock mass deformation. This paper presents laboratory measurements necessary to quantitatively interpret the reflected voltage signatures. Cables were sheared and extended to correlate measured cable deformation with reflected voltage signals. Laboratory testing included development of grout mixtures with optimum properties for field installation and performance of a TDR (Time Domain Reflectometry) monitoring system. Finally, the interpretive techniques developed through laboratory measurements were applied to previously collected field data to extract hitherto unrealized information.

  15. Workshop on Advancing Experimental Rock Deformation Research: Scientific and Technical Needs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tullis, Terry E.

    A workshop for the experimental rock deformation community was held in Boston on August 16-19, 2012, following some similar but smaller preliminary meetings. It was sponsored primarily by the NSF, with additional support from the DOE, the SCEC, and in-kind support by the USGS. A white paper summarizing the active discussions at the workshop and the outcomes is available (https://brownbox.brown.edu/download.php?hash=0b854d11). Those attending included practitioners of experimental rock deformation, i.e., those who conduct laboratory experiments, as well as users of the data provided by practitioners, namely field geologists, seismologists, geodynamicists, earthquake modelers, and scientists from the oil and gas industry. Amore » considerable fraction of those attending were early-career scientists. The discussion initially focused on identifying the most important unsolved scientific problems in all of the research areas represented by the users that experiments would help solve. This initial session was followed by wide-ranging discussions of the most critical problems faced by practitioners, particularly by early-career scientists. The discussion also focused on the need for designing and building the next generation of experimental rock deformation equipment required to meet the identified scientific challenges. The workshop participants concluded that creation of an experimental rock deformation community organization is needed to address many of the scientific, technical, and demographic problems faced by this community. A decision was made to hold an organizational meeting of this new organization in San Francisco on December 1-2, 2012, just prior to the Fall Meeting of the AGU. The community has decided to name this new organization “Deformation Experimentation at the Frontier Of Rock and Mineral research” or DEFORM. As of May 1, 2013, 64 institutions have asked to be members of DEFORM.« less

  16. 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.

  17. 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.

  18. 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…

  19. Strain partitioning in shales during elastic and creep deformation observed by synchrotron X-ray micro-tomography.

    NASA Astrophysics Data System (ADS)

    Sone, H.; Cheung, C.; Rivers, M. L.; Wang, Y.; Yu, T.

    2016-12-01

    Knowledge about the ductile time-dependent constitutive behavior of geological materials is essential when evaluating the long-term integrity of subsurface structures and predicting the long-term geomechanical response of the surrounding formations. To this end, it is not only important to measure the bulk time-dependent behavior but also essential to understand the microscale mechanism by which rocks exhibit time-dependence, because laboratory data needs to be extrapolated to time-scales much beyond laboratory experiments. We conducted long-term creep experiments using Green River shale samples and obtained synchrotron X-ray images during the tests in an attempt to capture the microscale strain-partitioning that occurs within the sample. Shale samples of few millimeter dimensions were stressed up to several tens of MPa by a spring-loaded device within an X-ray transparent load frame, and the load was held constant for up to several months to allow creep deformation. Tomographic images of about 5 micron resolution were reconstructed from images collected at different timings of the experiment, which allows us to investigate where and how much strain localized during elastic and creep deformation. Tracking the position of some outstanding features in the rock texture (e.g. pyrite grains, organic material patches) indicate that strain magnitudes expected from the sample elastic and relaxation modulus can be successfully recovered from the tomographic images. We also attempt to use digital volume correlation to track sub-voxel displacements and to characterize the spatial heterogeneity of the deformation.

  20. 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

  1. 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

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

    PubMed Central

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

  3. Redefining authentic research experiences in introductory biology laboratories and barriers to their implementation.

    PubMed

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

  4. Oscillations of a deformed liquid drop in an acoustic field

    NASA Astrophysics Data System (ADS)

    Shi, Tao; Apfel, Robert E.

    1995-07-01

    The oscillations of an axially symmetric liquid drop in an acoustic standing wave field in air have been studied using the boundary integral method. The interaction between the drop oscillation and sound field has been included in this analysis. Our computations focus on the frequency shift of small-amplitude oscillations of an acoustically deformed drop typical of a drop levitated in air. In the presence or absence of gravity, the trend and the magnitude of the frequency shift have been given in terms of drop size, drop deformation, and the strength of the sound field. Our calculations are compared with experiments performed on the United States Microgravity Laboratory (USML-1) and with ground-based measurements, and are found to be in good agreement within the accuracy of the experimental data.

  5. 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. © 2014 The International Union of Biochemistry and Molecular Biology.

  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. 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.

  8. Microscale Experiments in the Organic Chemistry Laboratory.

    ERIC Educational Resources Information Center

    Williamson, Kenneth L.

    1991-01-01

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

  9. 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)

  10. Stress, deformation and micromorphological aspects of soil freezing under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Jetchick, Elizabeth

    In this thesis, frost heave is viewed as a process resulting from the interactions between thermodynamic conditions, soil environment controls such as texture, stress/deformation conditions and soil microstructure. A series of laboratory experiments was devised to investigate the links between these aspects. Because a limited number of studies exist on the development of internal stresses and strains in freezing soil, the work focussed on obtaining rheological data using conventional soil strain gauges and prototype stress transducers. A fine-grained unstructured silt was placed in a column (30 cm diameter by 100 cm length) and subjected to freezing and freeze-thaw cycles from the top down, lasting up to three months. Heat and water flows, as well as stresses and strains were monitored. The frozen soil was sectioned at the end of four of the experiments to examine the soil fabrics that had developed. From the experimental results, schematic stress and strain curves are proposed. For a single freeze cycle, compressive normal and tensile normal stresses were recorded simultaneously by the measuring devices within the freezing soil profile. Ice lens inception took place when the stress field changed, a condition which occurred either at the frost front level or at the base of the growing ice lens. Negative and positive strains reflected the different stress states that were sustained below and above the freezing front. Negative strains or soil consolidation took place as stresses increased before the passage of the frost line. Negligible soil strains were recorded as maximum soil consolidation was attained, before soil expansion. Distinct positive strain patterns indicating secondary and continuing heave, were recorded simultaneously throughout a thickness of soil, over a range of temperatures. Ice lens growth mostly took place as secondary frost heave, but continuing heave was measured, and the temperature conditions for both types of heave were determined. During

  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. 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)

  13. Deformation mechanism of CrN/nitriding coated steel in wear and nano-scratch experiments under heavy loading conditions

    NASA Astrophysics Data System (ADS)

    Wang, Yongguang; Chen, Yao; Zhao, Dong; Lu, Xiaolong; Liu, Weiwei; Qi, Fei; Chen, Yang

    2018-07-01

    CrN coatings are widely used to protect metals from wear in industrial engineering. However, fundamental deformation mechanism of these coatings under heavy loading conditions remains elusive. In this paper, multilayered hard coatings with a CrN matrix and a supporting layer were developed by means of the hybrid deposition process combined with PVD and ionicnitriding. The tribological behavior of coatings with and without ionicnitriding were investigated by a pin-on-disk arrangement under heavy loading conditions. In addition, the deformation mechanism of the multilayered hard coatings was studied by nano-scratch experiment with ramp load model, which has not been discussed previously. It was found that the deformation process of coatings could be divided into three regimes based on the evolution of frictional coefficient. The insertion of nitriding films leads to the further increase in frictional resistance owing to the elastic-plastic deformation. The results and analysis reveal some insights into the coating design for multilayered hard coatings with the consideration of deformation mechanisms.

  14. 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.

  15. 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.

  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. Experiences and prospects of nuclear astrophysics in underground laboratories

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Junker, M.

    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 tomore » 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.« less

  18. Patients cured of acromegaly do not experience improvement of their skull deformities.

    PubMed

    Rick, Jonathan W; Jahangiri, Arman; Flanigan, Patrick M; Aghi, Manish K

    2017-04-01

    Acromegaly is a rare disease that is associated with many co-morbidities. This condition also causes progressive deformity of the skull which includes frontal bossing and cranial thickening. Surgical and/or medical management can cure this condition in many patients, but it is not understood if patients cured of acromegaly experience regression of their skull deformities. We performed a retrospective analysis on patients treated at our dedicated pituitary center from 2009 to 2014. We looked at all MRI images taken during the treatment of these patients and recorded measurements on eight skull dimensions. We then analyzed these measurements for changes over time. 29 patients underwent curative treatment for acromegaly within our timeframe. The mean age for this population was 45.0 years old (range 19-70) and 55.2 % (n = 16) were female. All of these patients were treated with a transsphenoidal resection for a somatotropic pituitary adenoma. 9 (31.1%) of these patients required further medical therapy to be cured. We found statically significant variation in the coronal width of the sella turcica after therapy, which is likely attributable to changes from transsphenoidal surgery. None of the other dimensions had significant variation over time after cure. Patients cured of acromegaly should not expect natural regression of their skull deformities. Our study suggests that both frontal bossing and cranial thickening do not return to normal after cure.

  19. Experiments on planetary ices at UCL

    NASA Astrophysics Data System (ADS)

    Grindrod, P. M.; Fortes, A. D.; Wood, I. G.; Dobson, D.; Sammonds, P. R.; Stone-Drake, L.; Vocadlo, L.

    2007-08-01

    Using a suite of techniques and equipment, we conduct several different types of experiments on planetary ices at UCL. Samples are prepared in the Ice Physics Laboratory, which consists of a 5 chamber complex of inter-connected cold rooms, controllable from +30 to -30 deg C. Within this laboratory we have a functioning triaxial deformation cell operating at low temperature (down to -90 deg C) and high pressures (300 MPa), an Automatic Ice Fabric Analyser (AIFA) and a low-temperature microscope with CCD output. Polycrystalline samples, 40mm diameter by 100mm long, are compressed in the triaxial rig with a confining pressure; single crystal specimens are compressed in a separate uniaxial creep rig which operates at zero confining pressure for surface studies. A cold stage is also available for study of ice microstructural studies on our new Jeol JSM-6480LV SEM, which also allows tensile, compression and/or bending tests, with load ranges from less than 2N to 5000N. Finally, we also use a cold stage on a new PANalytical, X'pert PRO MPD, high resolution powder diffractometer to study the structure and phase behaviour of icy materials. Recent highlights of our work include: (1) derivation of a manufacturing process for methane clathrate at low temperatures, analysed in the X-Ray Diffraction Laboratory, for future rheological experiments, (2) analysed the growth behaviour of MS11, (3) refurbished and commenced calibration tests on the triaxial deformation cell using ice Ih, and (4) performed creep tests on gypsum and epsomite using the single crystal deformation cell. Further experiments will build on these preliminary results.

  20. 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.

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

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Researchers perform tests at Kennedy Space Center. New facilities for such research will be provided at the Space Experiment Research Procession Laboratory (SERPL). The SERPL is a planned 100,000-square-foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  2. 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,…

  3. 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…

  4. Semantic modeling of plastic deformation of polycrystalline rock

    NASA Astrophysics Data System (ADS)

    Babaie, Hassan A.; Davarpanah, Armita

    2018-02-01

    We have developed the first iteration of the Plastic Rock Deformation (PRD) ontology by modeling the semantics of a selected set of deformational processes and mechanisms that produce, reconfigure, displace, and/or consume the material components of inhomogeneous polycrystalline rocks. The PRD knowledge model also classifies and formalizes the properties (relations) that hold between instances of the dynamic physical and chemical processes and the rock components, the complex physio-chemical, mathematical, and informational concepts of the plastic rock deformation system, the measured or calculated laboratory testing conditions, experimental procedures and protocols, the state and system variables, and the empirical flow laws that define the inter-relationships among the variables. The ontology reuses classes and properties from several existing ontologies that are built for physics, chemistry, biology, and mathematics. With its flexible design, the PRD ontology is well positioned to incrementally develop into a model that more fully represents the knowledge of plastic deformation of polycrystalline rocks in the future. The domain ontology will be used to consistently annotate varied data and information related to the microstructures and the physical and chemical processes that produce them at different spatial and temporal scales in the laboratory and in the solid Earth. The PRDKB knowledge base, when built based on the ontology, will help the community of experimental structural geologists and metamorphic petrologists to coherently and uniformly distribute, discover, access, share, and use their data through automated reasoning and integration and query of heterogeneous experimental deformation data that originate from autonomous rock testing laboratories.

  5. Non-affine deformations in polymer hydrogels

    PubMed Central

    Wen, Qi; Basu, Anindita; Janmey, Paul A.; Yodh, A. G.

    2012-01-01

    Most theories of soft matter elasticity assume that the local strain in a sample after deformation is identical everywhere and equal to the macroscopic strain, or equivalently that the deformation is affine. We discuss the elasticity of hydrogels of crosslinked polymers with special attention to affine and non-affine theories of elasticity. Experimental procedures to measure non-affine deformations are also described. Entropic theories, which account for gel elasticity based on stretching out individual polymer chains, predict affine deformations. In contrast, simulations of network deformation that result in bending of the stiff constituent filaments generally predict non-affine behavior. Results from experiments show significant non-affine deformation in hydrogels even when they are formed by flexible polymers for which bending would appear to be negligible compared to stretching. However, this finding is not necessarily an experimental proof of the non-affine model for elasticity. We emphasize the insights gained from experiments using confocal rheoscope and show that, in addition to filament bending, sample micro-inhomogeneity can be a significant alternative source of non-affine deformation. PMID:23002395

  6. Modeling Laser-Driven Laboratory Astrophysics Experiments Using the CRASH Code

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  7. 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,…

  8. Why did Arabia separate from Africa? Insights from 3-D laboratory experiments

    NASA Astrophysics Data System (ADS)

    Bellahsen, N.; Faccenna, C.; Funiciello, F.; Daniel, J. M.; Jolivet, L.

    2003-11-01

    We have performed 3-D scaled lithospheric experiments to investigate the role of the gravitational force exerted by a subducting slab on the deformation of the subducting plate itself. Experiments have been constructed using a dense silicone putty plate, to simulate a thin viscous lithosphere, floating in the middle of a large box filled with glucose syrup, simulating the upper mantle. We examine three different plate configurations: (i) subduction of a uniform oceanic plate, (ii) subduction of an oceanic-continental plate system and, (iii) subduction of a more complex oceanic-continental system simulating the asymmetric Africa-Eurasia system. Each model has been performed with and without the presence of a circular weak zone inside the subducting plate to test the near-surface weakening effect of a plume activity. Our results show that a subducting plate can deform in its interior only if the force distribution varies laterally along the subduction zone, i.e. by the asymmetrical entrance of continental material along the trench. In particular, extensional deformation of the plate occurs when a portion of the subduction zone is locked by the collisional process. The results of this study can be used to analyze the formation of the Arabian plate. We found that intraplate stresses, similar to those that generated the Africa-Arabia break-up, can be related to the Neogene evolution of the northern convergent margin of the African plate, where a lateral change from collision (Mediterranean and Bitlis) to active subduction (Makran) has been described. Second, intraplate stress and strain localization are favored by the presence of a weakness zone, such as the one generated by the Afar plume, producing a pattern of extensional deformation belts resembling the Red Sea-Gulf of Aden rift system.

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

    ERIC Educational Resources Information Center

    Leung, Sam H.; Angel, Stephen A.

    2004-01-01

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

  10. Cyclic deformation-induced solute transport in tissue scaffolds with computer designed, interconnected, pore networks: experiments and simulations.

    PubMed

    Den Buijs, Jorn Op; Dragomir-Daescu, Dan; Ritman, Erik L

    2009-08-01

    Nutrient supply and waste removal in porous tissue engineering scaffolds decrease from the periphery to the center, leading to limited depth of ingrowth of new tissue into the scaffold. However, as many tissues experience cyclic physiological strains, this may provide a mechanism to enhance solute transport in vivo before vascularization of the scaffold. The hypothesis of this study was that pore cross-sectional geometry and interconnectivity are of major importance for the effectiveness of cyclic deformation-induced solute transport. Transparent elastic polyurethane scaffolds, with computer-programmed design of pore networks in the form of interconnected channels, were fabricated using a 3D printing and injection molding technique. The scaffold pores were loaded with a colored tracer for optical contrast, cyclically compressed with deformations of 10 and 15% of the original undeformed height at 1.0 Hz. Digital imaging was used to quantify the spatial distribution of the tracer concentration within the pores. Numerical simulations of a fluid-structure interaction model of deformation-induced solute transport were compared to the experimental data. The results of experiments and modeling agreed well and showed that pore interconnectivity heavily influences deformation-induced solute transport. Pore cross-sectional geometry appears to be of less relative importance in interconnected pore networks. Validated computer models of solute transport can be used to design optimal scaffold pore geometries that will enhance the convective transport of nutrients inside the scaffold and the removal of waste, thus improving the cell survivability deep inside the scaffold.

  11. Cyclic Deformation-Induced Solute Transport in Tissue Scaffolds with Computer Designed, Interconnected, Pore Networks: Experiments and Simulations

    PubMed Central

    Op Den Buijs, Jorn; Dragomir-Daescu, Dan; Ritman, Erik L.

    2014-01-01

    Nutrient supply and waste removal in porous tissue engineering scaffolds decrease from the periphery to the center, leading to limited depth of ingrowth of new tissue into the scaffold. However, as many tissues experience cyclic physiological strains, this may provide a mechanism to enhance solute transport in vivo before vascularization of the scaffold. The hypothesis of this study was that pore cross-sectional geometry and interconnectivity are of major importance for the effectiveness of cyclic deformation-induced solute transport. Transparent elastic polyurethane scaffolds, with computer-programmed design of pore networks in the form of interconnected channels, were fabricated using a 3D printing and injection molding technique. The scaffold pores were loaded with a colored tracer for optical contrast, cyclically compressed with deformations of 10 and 15% of the original undeformed height at 1.0 Hz. Digital imaging was used to quantify the spatial distribution of the tracer concentration within the pores. Numerical simulations of a fluid–structure interaction model of deformation-induced solute transport were compared to the experimental data. The results of experiments and modeling agreed well and showed that pore interconnectivity heavily influences deformation-induced solute transport. Pore cross-sectional geometry appears to be of less relative importance in interconnected pore networks. Validated computer models of solute transport can be used to design optimal scaffold pore geometries that will enhance the convective transport of nutrients inside the scaffold and the removal of waste, thus improving the cell survivability deep inside the scaffold. PMID:19466547

  12. Stress and deformation characteristics of sea ice in a high resolution numerical sea ice model.

    NASA Astrophysics Data System (ADS)

    Heorton, Harry; Feltham, Daniel; Tsamados, Michel

    2017-04-01

    The drift and deformation of sea ice floating on the polar oceans is due to the applied wind and ocean currents. The deformations of sea ice over ocean basin length scales have observable patterns; cracks and leads in satellite images and within the velocity fields generated from floe tracking. In a climate sea ice model the deformation of sea ice over ocean basin length scales is modelled using a rheology that represents the relationship between stresses and deformation within the sea ice cover. Here we investigate the link between observable deformation characteristics and the underlying internal sea ice stresses and force balance using the Los Alamos numerical sea ice climate model. In order to mimic laboratory experiments on the deformation of small cubes of sea ice we have developed an idealised square domain that tests the model response at spatial resolutions of up to 500m. We use the Elastic Anisotropic Plastic and Elastic Viscous Plastic rheologies, comparing their stability over varying resolutions and time scales. Sea ice within the domain is forced by idealised winds in order to compare the confinement of wind stresses and internal sea ice stresses. We document the characteristic deformation patterns of convergent, divergent and rotating stress states.

  13. A fundamental discussion of what triggers localized deformation in geological materials

    NASA Astrophysics Data System (ADS)

    Peters, Max; Paesold, Martin; Poulet, Thomas; Herwegh, Marco; Regenauer-Lieb, Klaus; Veveakis, Manolis

    2015-04-01

    Discontinuous or localized structures are often marked by the transition from a homogeneously deforming into a highly localized mode. This transition has extensively been described in ductile shear zones, folding and pinch-and-swell boudinage, in natural examples, rock deformation experiments and numerical simulations, at various scales. It is conventionally assumed that ductile instabilities, which act as triggers for localized deformation, exclusively arise from structural heterogeneities, i.e. geometric interactions or material imperfections. However, Hansen et al. (2012) concluded from recent laboratory experiments that localized deformation might arise out of steady-state conditions, where the size of initial perturbations was either insufficiently large to trigger localization, or these heterogeneities were simply negligible at the scale of observation. We therefore propose the existence of a principal localization phenomenon, which is based on the material-specific rate-dependency of deformation at elevated temperatures. The concept of strain localization out of a mechanical steady state in a homogeneous material at a critical material parameter and/or deformation rate has previously been discussed for engineering materials (Gruntfest, 1963) and frictional faults (Veveakis et al., 2010). We expand this theory to visco-plastic carbonate rocks, considering deformation conditions and mechanisms encountered in naturally deformed rocks. In the numerical simulation, we implement a grain-size evolution based on the Paleowattmeter scaling relationship of Austin & Evans (2007), which takes both grain size sensitive (diffusion) and insensitive (dislocation) creep combined with grain growth into account (Herwegh et al., 2014). Based on constant strain rate simulations carried out under isothermal boundary conditions, we explore the parameter space in order to obtain the criteria for localization. We determine the criteria for the onset of localization, i.e. the

  14. 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

  15. 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.

  16. Complementarity of Laboratory and Space Experiments on Reconnexion

    NASA Astrophysics Data System (ADS)

    Moore, T. E.; Chen, L. J.

    2017-12-01

    Reconnection research has for some time been focused upon understanding the electron scale physics in the electron diffusion region (EDR), both in space and in the laboratory. Ren et al. [2008 PRL] reported identification and resolution of the EDR in the MRX laboratory experiment. More recently, Burch et al. [2016] reported identification of the EDR in reconnection at the magnetopause. Space observations from MMS have also provided the first capability to resolve and measure the full electron VDF within and around the EDR, making it possible to observe electron acceleration by the reconnection electric field and revealing new features of the EDR. Laboratory and space explorations of EDR physics may complement and inspire each other in other ways to be discussed by the panel.

  17. The Timing of an Experiment in the Laboratory Program Is Crucial for the Student Laboratory Experience: Acylation of Ferrocene as a Case Study

    ERIC Educational Resources Information Center

    Southam, Daniel C.; Shand, Bradley; Buntine, Mark A.; Kable, Scott H.; Read, Justin R.; Morris, Jonathan C.

    2013-01-01

    An assessment of the acylation of ferrocene laboratory exercise across three successive years resulted in a significant fluctuation in student perception of the experiment. This perception was measured by collecting student responses to an instrument immediately after the experiment, which includes Likert and open-ended responses from the student.…

  18. Deformation in the mantle wedge associated with Laramide flat-slab subduction and implications for surface deformation during the Laramide orogeny

    NASA Astrophysics Data System (ADS)

    Behr, W. M.; Smith, D.

    2016-12-01

    Laramide crustal deformation in the Rocky Mountains of the west-central United States is often considered to relate to a narrow segment of shallow subduction of the Farallon slab, but there is no consensus as to how deformation along the slab-mantle lithosphere interface was accommodated. Here we investigate deformation in mantle rocks associated with hydration and shear above the flat-slab at its contact with the base of the North American plate. The rocks we focus on are deformed, hydrated, ultramafic inclusions hosted within diatremes of the Navajo Volcanic Field in the central Colorado Plateau that erupted during the waning stages of the Laramide orogeny. We document a range of deformation textures, including granular peridotites, porphyroclastic peridotites, mylonites, and cataclasites, which we interpret to reflect different proximities to a slab-mantle-interface shear zone. Mineral assemblages and chemistries constrain deformation to hydrous conditions in the temperature range 550-750 C. Despite the presence of hydrous phyllosilicates in modal percentages of up to 30%, deformation was dominated by dislocation creep in olivine. The mylonites exhibit an uncommon lattice preferred orientation (LPO) in olivine, known as B-type LPO in which the a-axes are aligned perpendicular to the flow direction. The low temperature, hydrated setting in which these fabrics formed is consistent with laboratory experiments that indicate B-type LPOs form under conditions of high stress and high water contents; furthermore, the mantle wedge context of these LPOs is consistent with observations of trench-parallel anisotropy in the mantle wedge above many modern subduction zones. Differential stress magnitudes in the mylonitic rocks estimated using paleopiezometry range from 290 to 444 MPa, and calculated effective viscosities using a wet olivine flow law are on the order of 10^19 to 10^23 Pa s. The high stress magnitudes, high effective viscosities, and high strains recorded in

  19. Biobased Organic Chemistry Laboratories as Sustainable Experiment Alternatives

    ERIC Educational Resources Information Center

    Silverman, Julian R.

    2016-01-01

    As nonrenewable resources deplete and educators seek relevant interdisciplinary content for organic chemistry instruction, biobased laboratory experiments present themselves as potential alternatives to petroleum-based transformations, which offer themselves as sustainable variations on important themes. Following the principles of green chemistry…

  20. Consequences of Melt-Preferred Orientation for Magmatic Segregation in Deforming Mantle Rock

    NASA Astrophysics Data System (ADS)

    Katz, R. F.; Taylor-West, J.; Allwright, J.; Takei, Y.; Qi, C.; Kohlstedt, D. L.

    2014-12-01

    In partially molten regions of the mantle, deviatoric stresses cause large-scale deformation and mantle flow. The same stresses also lead to preferential wetting of coherently oriented grain boundaries [DK97, T10]. This alignment is called melt-preferred orientation (MPO). Because of the contrast between the physical properties of melt and solid grains, MPO has the potential to introduce anisotropy into the mechanical and transport properties of the liquid/solid aggregate. Here we consider the possible consequences for (and of) anisotropic viscosity and permeability of the partially molten aggregate. The consequences are evaluated in the context of laboratory experiments on partially molten rocks. The controlled experiments involve deformation of an initially uniform mixture of solid olivine and liquid basalt [KZK10]. The resultant patterns of melt segregation include two robust features: (i) melt segregation into bands with high melt fraction oriented at a low angle to the shear plane; and (ii) melt segregation associated with an imposed gradient in shear stress, in experiments where this is present. Although there are other reproducible features of experiments, these are the most robust and provide a challenge to models. A theoretical model for the effect of MPO on mantle viscosity under diffusion creep is available [TH09] and makes predictions that are consistent with laboratory experiments [TK13,KT13,QKKT14,AK14]. We review the mechanics of this model and the predictions for flow in torsional and pipe Poiseuille flow, showing a quantitative comparison with experimental results. Furthermore, it is logical to expect MPO to lead to anisotropy of permeability, and we present a general model of tensorial permeability. We demonstrate the consequences of this anisotropy for simple shear deformation of a partially molten rock. REFERENCES: DK97 = Daines & Kohlstedt (1997), JGR, 10.1029/97JB00393. T10 = Takei (2010), JGR, 10.1029/2009JB006568. KZK10 = King, Zimmerman

  1. Circular Dichroism Spectroscopy: Enhancing a Traditional Undergraduate Biochemistry Laboratory Experience

    ERIC Educational Resources Information Center

    Lewis, Russell L.; Seal, Erin L.; Lorts, Aimee R.; Stewart, Amanda L.

    2017-01-01

    The undergraduate biochemistry laboratory curriculum is designed to provide students with experience in protein isolation and purification protocols as well as various data analysis techniques, which enhance the biochemistry lecture course and give students a broad range of tools upon which to build in graduate level laboratories or once they…

  2. Real-Time Internet Mediated Laboratory Experiments for Distance Education Students.

    ERIC Educational Resources Information Center

    Lemckert, Charles; Florance, John

    2002-01-01

    Discusses the demand for distance education opportunities in engineering and science and considers delivery methods for theoretical content and for laboratory work. Explains the Real-Time Internet Mediated Laboratory Experiments (RTIMLE) that use the World Wide Web, and suggests that RTIMLE may be most appropriate for students who already have…

  3. 75 FR 15675 - Professional Research Experience Program in Chemical Science and Technology Laboratory...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... in physics, chemistry, mathematics, computer science, or engineering. Institutions should have a 4..., mathematics, computer science, or engineering with work experiences in laboratories or other settings...-0141-01] Professional Research Experience Program in Chemical Science and Technology Laboratory...

  4. Laboratory simulation of volcano seismicity.

    PubMed

    Benson, Philip M; Vinciguerra, Sergio; Meredith, Philip G; Young, R Paul

    2008-10-10

    The physical processes generating seismicity within volcanic edifices are highly complex and not fully understood. We report results from a laboratory experiment in which basalt from Mount Etna volcano (Italy) was deformed and fractured. The experiment was monitored with an array of transducers around the sample to permit full-waveform capture, location, and analysis of microseismic events. Rapid post-failure decompression of the water-filled pore volume and damage zone triggered many low-frequency events, analogous to volcanic long-period seismicity. The low frequencies were associated with pore fluid decompression and were located in the damage zone in the fractured sample; these events exhibited a weak component of shear (double-couple) slip, consistent with fluid-driven events occurring beneath active volcanoes.

  5. Static response of deformable microchannels

    NASA Astrophysics Data System (ADS)

    Christov, Ivan C.; Sidhore, Tanmay C.

    2017-11-01

    Microfluidic channels manufactured from PDMS are a key component of lab-on-a-chip devices. Experimentally, rectangular microchannels are found to deform into a non-rectangular cross-section due to fluid-structure interactions. Deformation affects the flow profile, which results in a nonlinear relationship between the volumetric flow rate and the pressure drop. We develop a framework, within the lubrication approximation (l >> w >> h), to self-consistently derive flow rate-pressure drop relations. Emphasis is placed on handling different types of elastic response: from pure plate-bending, to half-space deformation, to membrane stretching. The ``simplest'' model (Stokes flow in a 3D rectangular channel capped with a linearly elastic Kirchhoff-Love plate) agrees well with recent experiments. We also simulate the static response of such microfluidic channels under laminar flow conditions using ANSYSWorkbench. Simulations are calibrated using experimental flow rate-pressure drop data from the literature. The simulations provide highly resolved deformation profiles, which are difficult to measure experimentally. By comparing simulations, experiments and our theoretical models, we show good agreement in many flow/deformation regimes, without any fitting parameters.

  6. Imbibition with swelling: Capillary rise in thin deformable porous media

    NASA Astrophysics Data System (ADS)

    Kvick, Mathias; Martinez, D. Mark; Hewitt, Duncan R.; Balmforth, Neil J.

    2017-07-01

    The imbibition of a liquid into a thin deformable porous substrate driven by capillary suction is considered. The substrate is initially dry and has uniform porosity and thickness. Two-phase flow theory is used to describe how the liquid flows through the pore space behind the wetting front when out-of-plane deformation of the solid matrix is considered. Neglecting gravity and evaporation, standard shallow-layer scalings are used to construct a reduced model of the dynamics. The model predicts convergence to a self-similar behavior in all regions except near the wetting front, where a boundary layer arises whose structure narrows with the advance of the front. Over time, the rise height approaches the similarity scaling of t1 /2, as in the classical Washburn or BCLW law. The results are compared with a series of laboratory experiments using cellulose paper sheets, which provide qualitative agreement.

  7. The Effect of Fracture Filler Composition on the Parameters of Shear Deformation Regime

    NASA Astrophysics Data System (ADS)

    Pavlov, D.; Ostapchuk, A.; Batuhtin, I.

    2015-12-01

    Geomechanical models of different slip mode nucleation and transformation can be developed basing on laboratory experiments, in which regularities of shear deformation of gouge-filled faults are studied. It's known that the spectrum of possible slip modes is defined by both macroscopic deformation characteristics of the fault and mesoscale structure of fault filler. Small variations of structural parameters of the filler may lead to a radical change of slip mode [1, 2]. This study presents results of laboratory experiments investigating regularities of shear deformation of discontinuities filled with multicomponent granular material. Qualitative correspondence between experimental results and natural phenomena is detected. The experiments were carried out in the classical "slider model" statement. A granite block slides under shear load on a granite substrate. The contact gap between rough surfaces was filled with a discrete material, which simulated the principal slip zone of a fault. The filler components were quartz sand, salt, glass beads, granite crumb, corundum, clay and pyrophyllite. An entire spectrum of possible slip modes was obtained - from stable slip to slow-slip events and to regular stick-slip with various coseismic displacements realized per one act of instability. Mixing several components in different proportions, it became possible to trace the gradual transition from stable slip to regular stick-slip, from slow-slip events to fast-slip events. Depending on specific filler component content, increasing the portion of one of the components may lead to both a linear and a non-linear change of slip event moment (a laboratory equivalent of the seismic moment). For different filler compositions durations of equal-moment events may differ by more than two orders of magnitude. The findings can be very useful for developing geomechnical models of nucleation and transformation of different slip modes observed at natural faults. The work was supported by

  8. New Insights on the Rheology of Olivine Deformed under Lithospheric Temperature Conditions

    NASA Astrophysics Data System (ADS)

    Cordier, P.; Demouchy, S. A.; Mussi, A.; Tommasi, A.

    2014-12-01

    Rheology of mantle rocks at lithospheric temperatures remains poorly constrained, since most experimental studies on creep mechanisms of olivine single crystals ((MgFe)2SiO4, Pbnm) and polycrystalline olivine aggregates were performed at high-temperatures (T >> 1200oC). In this study, we report results from deformation experiments on oriented single crystals of San Carlos olivine and polycrystalline olivine aggregate at temperatures relevant of the uppermost mantle (ranging from 800o to 1090oC) in tri-axial compression. The experiments were carried out at a confining pressure of 300 MPa in a high-resolution gas-medium mechanical testing apparatus at various constant strain rates (from 7 x 10-6 s-1 to 1 x 10-4 s-1). Mechanical tests show that mantle lithosphere is actually weaker than previously inferred from the extrapolation of high-temperature experiments. In this study, we present characterization of dislocation microstructures based on transmission electron microscopy and electron tomography. It is shown that below 1000°C, dislocation activity is restricted to [001] glide with a strong predominance of {110} as glide planes. We observe recovery mechanisms which suggest that the mechanical properties observed in laboratory experiments represent an upper bound for the actual behavior of olivine under lithospheric mantle conditions. Moreover, the drastic reduction in slip system activity observed questions the ability of deforming olivine aggregates in the ductile regime at such temperatures. We show that ductility is preserved thanks to the activation of alternative deformation mechanisms in grain boundaries involving disclinations.

  9. Artist rendition of the planned Space Experiment Research and Processing Laboratory

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The preliminary design for the Space Experiment Research and Processing Laboratory (SERPL) at Kennedy Space Center is shown in this artist's rendition. The SERPL is a planned 100,000-square- foot laboratory that will provide expanded and upgraded facilities for hosting International Space Station experiment processing. In addition, it will provide better support for other biological and life sciences payload processing at KSC. It will serve as a magnet facility for a planned 400-acre Space Station Commerce Park.

  10. A novel method of multi-scale simulation of macro-scale deformation and microstructure evolution on metal forming

    NASA Astrophysics Data System (ADS)

    Huang, Shiquan; Yi, Youping; Li, Pengchuan

    2011-05-01

    In recent years, multi-scale simulation technique of metal forming is gaining significant attention for prediction of the whole deformation process and microstructure evolution of product. The advances of numerical simulation at macro-scale level on metal forming are remarkable and the commercial FEM software, such as Deform2D/3D, has found a wide application in the fields of metal forming. However, the simulation method of multi-scale has little application due to the non-linearity of microstructure evolution during forming and the difficulty of modeling at the micro-scale level. This work deals with the modeling of microstructure evolution and a new method of multi-scale simulation in forging process. The aviation material 7050 aluminum alloy has been used as example for modeling of microstructure evolution. The corresponding thermal simulated experiment has been performed on Gleeble 1500 machine. The tested specimens have been analyzed for modeling of dislocation density, nucleation and growth of recrystallization(DRX). The source program using cellular automaton (CA) method has been developed to simulate the grain nucleation and growth, in which the change of grain topology structure caused by the metal deformation was considered. The physical fields at macro-scale level such as temperature field, stress and strain fields, which can be obtained by commercial software Deform 3D, are coupled with the deformed storage energy at micro-scale level by dislocation model to realize the multi-scale simulation. This method was explained by forging process simulation of the aircraft wheel hub forging. Coupled the results of Deform 3D with CA results, the forging deformation progress and the microstructure evolution at any point of forging could be simulated. For verifying the efficiency of simulation, experiments of aircraft wheel hub forging have been done in the laboratory and the comparison of simulation and experiment result has been discussed in details.

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

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  12. TOUGH-RBSN simulator for hydraulic fracture propagation within fractured media: Model validations against laboratory experiments

    NASA Astrophysics Data System (ADS)

    Kim, Kunhwi; Rutqvist, Jonny; Nakagawa, Seiji; Birkholzer, Jens

    2017-11-01

    This paper presents coupled hydro-mechanical modeling of hydraulic fracturing processes in complex fractured media using a discrete fracture network (DFN) approach. The individual physical processes in the fracture propagation are represented by separate program modules: the TOUGH2 code for multiphase flow and mass transport based on the finite volume approach; and the rigid-body-spring network (RBSN) model for mechanical and fracture-damage behavior, which are coupled with each other. Fractures are modeled as discrete features, of which the hydrological properties are evaluated from the fracture deformation and aperture change. The verification of the TOUGH-RBSN code is performed against a 2D analytical model for single hydraulic fracture propagation. Subsequently, modeling capabilities for hydraulic fracturing are demonstrated through simulations of laboratory experiments conducted on rock-analogue (soda-lime glass) samples containing a designed network of pre-existing fractures. Sensitivity analyses are also conducted by changing the modeling parameters, such as viscosity of injected fluid, strength of pre-existing fractures, and confining stress conditions. The hydraulic fracturing characteristics attributed to the modeling parameters are investigated through comparisons of the simulation results.

  13. Logjam Deformation: Experimental analogs with variable flow

    NASA Astrophysics Data System (ADS)

    Deshpande, N.; Crosby, B. T.

    2017-12-01

    Observed deformation of a massive, channel-spanning logjam in Big Creek, Idaho inspired a suite of physical experiments exploring logjam kinematics in a simplified but controlled setting. Using chopsticks as surrogates for logs, we conducted experiments in a 6 m long and 1.22 m wide channel with a semi-circular, textured bed. Nails driven into the bed restrain the chopsticks and initialize logjam formation. We conducted 24 hour experiments hours under two discharge conditions: (A) constant base discharge and (B) alternating discharge between the base flow and a doubled flow. After initial stabilization, we use high-resolution down-looking photographs at one-minute intervals to construct time-lapse videos and for Particle Image Velocimetry. Despite identical experimental protocols during stabilization, the starting configuration of chopsticks is markedly different for each run. In Experiment A, the orientations and packing of chopsticks is visibly less ordered than Experiment B. However, deformation in both experiments is accomplished by the same three mechanisms: rigid blocks that propagate downstream as v-shaped fronts bounded by shear planes, logjam-wide adjustments in response to the change in position of a key member, and independent logs whose trajectories either travel underneath the logjam or adjust unbounded in the backwater. Total compression is 46% and 80% for experiment A and B, respectively. Time-series of incremental displacements for both experiments decrease noisily over time, but zero displacement is never reached. Despite very different hydrologic forcings, cumulative rates of deformation for both experiments are similar, suggesting that the progressive deformation of disordered, elongate particles (chopsticks and logs) within a larger ensemble leads to denser packing, and that this mechanism best describes logjam deformation.

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

    NASA Astrophysics Data System (ADS)

    Gatlin, Todd Adam

    Graduate teaching assistants (GTAs) play a prominent role in chemistry laboratory instruction at research based universities. They teach almost all undergraduate chemistry laboratory courses. However, their role in laboratory instruction has often been overlooked in educational research. Interest in chemistry GTAs has been placed on training and their perceived expectations, but less attention has been paid to their experiences or their potential benefits from teaching. This work was designed to investigate GTAs' experiences in and benefits from laboratory instructional environments. This dissertation includes three related studies on GTAs' experiences teaching in general chemistry laboratories. Qualitative methods were used for each study. First, phenomenological analysis was used to explore GTAs' experiences in an expository laboratory program. Post-teaching interviews were the primary data source. GTAs experiences were described in three dimensions: doing, knowing, and transferring. Gains available to GTAs revolved around general teaching skills. However, no gains specifically related to scientific development were found in this laboratory format. Case-study methods were used to explore and illustrate ways GTAs develop a GTA self-image---the way they see themselves as instructors. Two general chemistry laboratory programs that represent two very different instructional frameworks were chosen for the context of this study. The first program used a cooperative project-based approach. The second program used weekly, verification-type activities. End of the semester interviews were collected and served as the primary data source. A follow-up case study of a new cohort of GTAs in the cooperative problem-based laboratory was undertaken to investigate changes in GTAs' self-images over the course of one semester. Pre-semester and post-semester interviews served as the primary data source. Findings suggest that GTAs' construction of their self-image is shaped through the

  15. 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…

  16. Friction properties and deformation mechanisms of halite(-mica) gouges from low to high sliding velocities

    NASA Astrophysics Data System (ADS)

    Buijze, Loes; Niemeijer, André R.; Han, Raehee; Shimamoto, Toshihiko; Spiers, Christopher J.

    2017-01-01

    The evolution of friction as a function of slip rate is important in understanding earthquake nucleation and propagation. Many laboratory experiments investigating friction of fault rocks are either conducted in the low velocity regime (10-8-10-4 ms-1) or in the high velocity regime (0.01-1 m s-1). Here, we report on the evolution of friction and corresponding operating deformation mechanisms in analog gouges deformed from low to high slip rates, bridging the gap between these low and high velocity regimes. We used halite and halite-muscovite gouges to simulate processes, governing friction, active in upper crustal quartzitic fault rocks, at conditions accessible in the laboratory. The gouges were deformed over a 7 orders of magnitude range of slip rate (10-7-1 m s-1) using a low-to-high velocity rotary shear apparatus, using a normal stress of 5 MPa and room-dry humidity. Microstructural analysis was conducted to study the deformation mechanisms. Four frictional regimes as a function of slip rate could be recognized from the mechanical data, showing a transitional regime and stable sliding (10-7-10-6 m s-1), unstable sliding and weakening (10-6-10-3 m s-1), hardening (10-2-10-1 m s-1) and strong weakening (10-1-1 m s-1). Each of the four regimes can be associated with a distinct microstructure, reflecting a transition from mainly brittle deformation accompanied by pressure solution healing to temperature activated deformation mechanisms. Additionally, the frictional response of a sliding gouge to a sudden acceleration of slip rate to seismic velocities was investigated. These showed an initial strengthening, the amount of which depended on the friction level at which the step was made, followed by strong slip weakening.

  17. Synchrotron in-situ deformation experiments of perovskite + (Mg,Fe)O aggregates under shallow lower mantle conditions (Invited)

    NASA Astrophysics Data System (ADS)

    Girard, J.; Amulele, G.; Farla, R. J.; Liu, Z.; Mohiuddin, A.; Karato, S.

    2013-12-01

    Experimental studies on rheological properties of mantle's minerals are crucial to understand the dynamics of Earth's interior, but direct experimental studies under the relevant lower mantle conditions are challenging. Most of the earlier studies were performed at lower mantle pressures but low temperatures using DAC (diamond anvil cell) (e.g., Merkel et al., 2003)), and in DAC experiments strain-rate and stress are unknown. Some previous studies were carried out under high pressures and high temperatures (e.g, Cordier et al., 2004) , but quantitative results on rheological behaviour of said minerals were not obtained. Here we present the results of the first in-situ deformation experiments of perovskite + (Mg,Fe)O (Pv + fp) aggregates using RDA (rotational Drickamer apparatus). The RDA has a better support for the anvils at high pressure than the more commonly used D-DIA apparatus and hence we can reach higher pressures and temperatures than the D-DIA. We have recently made new modifications to the cell assembly to reach the lower mantle conditions with less interference in X-ray diffraction patterns by the surrounding materials. The starting material was ringwoodite synthesized using a multi-anvil. In-situ deformation experiments were then carried at pressure up to 28 GPa (calculated from thermal EOS of Pt) and estimated temperatures up to 2200 K using RDA. Under these conditions, ringwoodite transformed to Pv + fp. We subsequently deformed the sample between strain rates of 10-4 to 10-5 s-1. Stress and strain were measured in-situ using X-ray synchrotron beam. The recovered sample analyses show evidence of perovskite+(Mg,Fe)O microstructure (Fig. 1). The radial X-ray diffraction data are being analysed to determine the stress levels of two minerals. Also microstructures of deformed specimens are studied to understand the deformation mechanisms and strain partitioning. The results will contribute towards our understanding of the rheological properties of the

  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. Deformation localization forming and destruction over a decompression zone.

    NASA Astrophysics Data System (ADS)

    Turuntaev, Sergey; Kondratyev, Viktor

    2017-04-01

    Development of a hydrocarbon field is accompanied by deformation processes in the surrounding rocks. In particular, a subsidence of oil strata cap above a decompression zone near producing wells causes changes in the stress-strain state of the upper rocks. It was shown previously, that the stress spatial changes form a kind of arch structures. The shear displacements along the arch surfaces can occur, and these displacements can cause a collapse of casing or even man-made earthquakes. We present here the results of laboratory simulation of such a phenomenon. A laboratory setup was made in the form of narrow box 30x30x5 cm3 in size with a hole (0.6 cm in diameter) in its bottom. As a model of porous strata, a foam-rubber layer of 4.0 -10.5cm in thick was used, which was saturated with water. The foam was sealed to the bottom of the box; the upper part of the box was filled by the dry sand. The sand was separated from the foam by thin polyethylene film to prevent the sand wetting. For visualization the sand deformations, the front wall of the box was made transparent and the sand was marked by horizontal strips of the colored sand. In the experiments, the water was pumped out the foam layer through the bottom hole. After pumping-out 50 ml of the water, the localization of sand deformations above the sink hole became noticeable; after pumping-out 100 ml of the water, the localized deformation forms an arch. At the same time, there was no displacement on the upper surface of the sand. To amplify the localization effect, the foam was additionally squeezed locally. In this case, three surfaces of the localized deformation appeared in the sand. The vertical displacements decreased essentially with height, but they reached the upper layers of the sand. An influence of vibration on arches forming was investigated. Several types of vibrators were used, they were placed inside the sand or on the front side of the box. Resulting accelerations were measured by the

  20. 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.

  1. 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…

  2. 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…

  3. 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…

  4. 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…

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

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  6. Two LANL laboratory astrophysics experiments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    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 drivenmore » 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.« less

  7. 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…

  8. 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.…

  9. Observation and Simulation of Motion and Deformation for Impact-Loaded Metal Cylinders

    NASA Astrophysics Data System (ADS)

    Hickman, R. J.; Wise, J. L.; Smith, J. A.; Mersch, J. P.; Robino, C. V.; Arguello, J. G.

    2015-06-01

    Complementary gas-gun experiments and computational simulations have examined the time-resolved motion and post-mortem deformation of cylindrical metal samples subjected to impact loading. The effect of propagation distance on a compressive waveform generated in a sample by planar impact at one end was determined using a velocity interferometer to track the longitudinal motion of the opposing rear (i.e., free) surface. Samples (24 or 25.4-mm diameter) were fabricated from aluminum (types 6061 and 7075), copper, stainless steel (type 316), and cobalt alloy L-605 (AMS 5759). For each material, waveforms obtained for a short (2 mm) and a long (25.4 mm) cylinder corresponded, respectively, to one-dimensional (i.e., uniaxial) and two-dimensional strain at the measurement point. The wave-profile data have been analyzed to (i) establish key dynamic material modeling parameters, (ii) assess the functionality of the Sierra Solid Mechanics-Presto (SierraSM/Presto) code, and (iii) identify the need for additional testing, material modeling, and/or code development. The results of subsequent simulations have been compared to benchmark recovery experiments that showed the residual plastic deformation incurred by cylinders following end, side, and corner impacts. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  10. 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.

  11. Acoustic Emission of Deformation Twinning in Magnesium.

    PubMed

    Mo, Chengyang; Wisner, Brian; Cabal, Mike; Hazeli, Kavan; Ramesh, K T; El Kadiri, Haitham; Al-Samman, Talal; Molodov, Konstantin D; Molodov, Dmitri A; Kontsos, Antonios

    2016-08-06

    The Acoustic Emission of deformation twinning in Magnesium is investigated in this article. Single crystal testing with combined full field deformation measurements, as well as polycrystalline testing inside the scanning electron microscope with simultaneous monitoring of texture evolution and twin nucleation were compared to testing at the laboratory scale with respect to recordings of Acoustic Emission activity. Single crystal testing revealed the formation of layered twin boundaries in areas of strain localization which was accompanied by distinct changes in the acoustic data. Testing inside the microscope directly showed twin nucleation, proliferation and growth as well as associated crystallographic reorientations. A post processing approach of the Acoustic Emission activity revealed the existence of a class of signals that appears in a strain range in which twinning is profuse, as validated by the in situ and ex situ microscopy observations. Features extracted from such activity were cross-correlated both with the available mechanical and microscopy data, as well as with the Acoustic Emission activity recorded at the laboratory scale for similarly prepared specimens. The overall approach demonstrates that the method of Acoustic Emission could provide real time volumetric information related to the activation of deformation twinning in Magnesium alloys, in spite of the complexity of the propagation phenomena, the possible activation of several deformation modes and the challenges posed by the sensing approach itself when applied in this type of materials evaluation approach.

  12. Influence of stress, temperature, and strain on calcite twins constrained by deformation experiments

    NASA Astrophysics Data System (ADS)

    Rybacki, E.; Evans, B.; Janssen, C.; Wirth, R.; Dresen, G.

    2013-08-01

    A series of low-strain triaxial compression and high-strain torsion experiments were performed on marble and limestone samples to examine the influence of stress, temperature, and strain on the evolution of twin density, the percentage of grains with 1, 2, or 3 twin sets, and the twin width—all parameters that have been suggested as either paleopiezometers or paleothermometers. Cylindrical and dog-bone-shaped samples were deformed in the semibrittle regime between 20 °C and 350 °C, under confining pressures of 50-400 MPa, and at strain rates of 10- 4-10- 6 s- 1. The samples sustained shear stresses, τ, up to 280 MPa, failing when deformed to shear strains γ > 1. The mean width of calcite twins increased with both temperature and strain, and thus, measurement of twin width provides only a rough estimation of peak temperature, unless additional constraints on deformation are known. In Carrara marble, the twin density, NL (no of twins/mm), increased as the rock hardened with strain and was approximately related to the peak differential stress, σ (MPa), by the relation σ=19.5±9.8√{N}. Dislocation tangles occurred along twin boundaries, resulting in a complicated cell structure, which also evolved with stress. As previously established, the square root of dislocation density, observed after quench, also correlated with peak stress. Apparently, both twin density and dislocation cell structure are important state variables for describing the strength of these rocks.

  13. Seismic evidence for widespread western-US deep-crustal deformation caused by extension

    USGS Publications Warehouse

    Moschetti, M.P.; Ritzwoller, M.H.; Lin, F.; Yang, Y.

    2010-01-01

    Laboratory experiments have established that many of the materials comprising the Earth are strongly anisotropic in terms of seismic-wave speeds. Observations of azimuthal and radial anisotropy in the upper mantle are attributed to the lattice-preferred orientation of olivine caused by the shear strains associated with deformation, and provide some of the most direct evidence for deformation and flow within the Earths interior. Although observations of crustal radial anisotropy would improve our understanding of crustal deformation and flow patterns resulting from tectonic processes, large-scale observations have been limited to regions of particularly thick crust. Here we show that observations from ambient noise tomography in the western United States reveal strong deep (middle to lower)-crustal radial anisotropy that is confined mainly to the geological provinces that have undergone significant extension during the Cenozoic Era (since 65 Myr ago). The coincidence of crustal radial anisotropy with the extensional provinces of the western United States suggests that the radial anisotropy results from the lattice-preferred orientation of anisotropic crustal minerals caused by extensional deformation. These observations also provide support for the hypothesis that the deep crust within these regions has undergone widespread and relatively uniform strain in response to crustal thinning and extension. ?? 2010 Macmillan Publishers Limited. All rights reserved.

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  15. Deformed barchans under alternating flows: Flume experiments and comparison with barchan dunes within Proctor Crater, Mars

    NASA Astrophysics Data System (ADS)

    Taniguchi, Keisuke; Endo, Noritaka

    2007-10-01

    It is generally considered that barchans, isolated crescentic-shaped dunes, develop where wind is unidirectional and the available sand is insufficient to cover the entire dune field; however, Bishop [Bishop, M.A., 2001. Seasonal variation of crescentic dune morphology and morphometry, Strzelecki Simpson desert, Australia. Earth Surface Process and Landforms 26, 783 791.] observed barchans that developed in areas where winds blow seasonally in opposite directions and described a peculiar deformation feature, the “rear slipface,” that is not found in ordinary barchans. Barchans under such bidirectional flows are poorly understood, and it is necessary to study barchans that formed under many different flow conditions. We conducted flume experiments to investigate the deformation of barchans under alternating water flow, and observed new deformation features in addition to rear slipfaces. We conclude that the deformation of barchans can be categorized into four types, one of which shows morphologies similar to barchans within Proctor Crater, Mars. The deformation type depends on the strength of the reverse flow relative to the forward flow and the absolute velocity of the forward flow. Comparison of our results with barchan dunes within Proctor Crater enable us to qualitatively estimate the wind strength and direction related to dune formation on Mars. These results are in agreement with those of Fenton et al. [Fenton, L.K., Toigo, A.D., Richardson, M.I., 2005. Aeolian processes in Proctor Crater on Mars: Mesoscale modeling of dune-forming winds. Journal of Geophysical Research 110 (E6), E06005.].

  16. Experimenting with Impacts in a Conceptual Physics or Descriptive Astronomy Laboratory

    ERIC Educational Resources Information Center

    LoPresto, Michael C.

    2016-01-01

    What follows is a description of the procedure for and results of a simple experiment on the formation of impact craters designed for the laboratory portions of lower mathematical-level general education science courses such as conceptual physics or descriptive astronomy. The experiment provides necessary experience with data collection and…

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

    PubMed Central

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

    2013-01-01

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

  18. 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.

  19. Plastic Deformation of Quartz: Unfinished business?

    NASA Astrophysics Data System (ADS)

    Paterson, M. S.

    2011-12-01

    Starting at Harvard in the mid-1930's, David Griggs built a series of high pressure machines for experimental rock deformation. One persistent aim was to achieve the plastic deformation of quartz. Each time he built a new machine for higher pressure and/or temperature, one of the first materials he tested would be quartz. This search went on through a 500 MPa liquid-medium machine at temperatures up to 300°C, then with a gas-medium machine for temperatures up to 800°C, and finally with a solid-medium machine for higher pressures and temperatures. Quartz proved stubbornly resistant to deformation except at extremely high stresses until, finally and somewhat serendipitously, it was found possible to deform quartz at relatively low stresses in the presence of water under special conditions. The breakthrough came in an experiment in a 1500 MPa solid-medium apparatus in which talc was used as pressure medium. At the temperature of the experiment, the talc dehydrated and so released water. Under these conditions, natural quartz proved to be very weak and to readily undergo plastic deformation, a phenomenon that became known as "hydrolytic weakening". Soon after this discovery, it was also found that certain synthetic single crystals could be easily deformed ab initio. These crystals were from a particular set that had been grown rapidly under hydrothermal conditions and had incorporated water during growth. Attempts in our laboratory to weaken crystals in a gas-medium apparatus at around 300 MPa by cooking dry quartz in the presence of added water were all unsuccessful, although we could deform wet synthetic crystals. There was considerable speculation about a role of high pressure in promoting hydrolytic weakening, but the dilemma was eventually clarified by electron microscope studies by Fitz Gerald and coworkers. These studies showed that crystals that had been subjected to high pressure and temperature in the solid-medium apparatus were extensively microcracked

  20. 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)

  1. 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

  2. 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…

  3. Responses to Anomalous Data Obtained from Repeatable Experiments in the Laboratory

    ERIC Educational Resources Information Center

    Lin, Jer-Yann

    2007-01-01

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

  4. Nuclear Deformation and Neutron Excess as Competing Effects for Dipole Strength in the Pygmy Region

    NASA Astrophysics Data System (ADS)

    Massarczyk, R.; Schwengner, R.; Dönau, F.; Frauendorf, S.; Anders, M.; Bemmerer, D.; Beyer, R.; Bhatia, C.; Birgersson, E.; Butterling, M.; Elekes, Z.; Ferrari, A.; Gooden, M. E.; Hannaske, R.; Junghans, A. R.; Kempe, M.; Kelley, J. H.; Kögler, T.; Matic, A.; Menzel, M. L.; Müller, S.; Reinhardt, T. P.; Röder, M.; Rusev, G.; Schilling, K. D.; Schmidt, K.; Schramm, G.; Tonchev, A. P.; Tornow, W.; Wagner, A.

    2014-02-01

    The electromagnetic dipole strength below the neutron-separation energy has been studied for the xenon isotopes with mass numbers A =124, 128, 132, and 134 in nuclear resonance fluorescence experiments using the γELBE bremsstrahlung facility at Helmholtz-Zentrum Dresden-Rossendorf and the HIγS facility at Triangle Universities Nuclear Laboratory Durham. The systematic study gained new information about the influence of the neutron excess as well as of nuclear deformation on the strength in the region of the pygmy dipole resonance. The results are compared with those obtained for the chain of molybdenum isotopes and with predictions of a random-phase approximation in a deformed basis. It turned out that the effect of nuclear deformation plays a minor role compared with the one caused by neutron excess. A global parametrization of the strength in terms of neutron and proton numbers allowed us to derive a formula capable of predicting the summed E1 strengths in the pygmy region for a wide mass range of nuclides.

  5. Nuclear deformation and neutron excess as competing effects for dipole strength in the pygmy region.

    PubMed

    Massarczyk, R; Schwengner, R; Dönau, F; Frauendorf, S; Anders, M; Bemmerer, D; Beyer, R; Bhatia, C; Birgersson, E; Butterling, M; Elekes, Z; Ferrari, A; Gooden, M E; Hannaske, R; Junghans, A R; Kempe, M; Kelley, J H; Kögler, T; Matic, A; Menzel, M L; Müller, S; Reinhardt, T P; Röder, M; Rusev, G; Schilling, K D; Schmidt, K; Schramm, G; Tonchev, A P; Tornow, W; Wagner, A

    2014-02-21

    The electromagnetic dipole strength below the neutron-separation energy has been studied for the xenon isotopes with mass numbers A=124, 128, 132, and 134 in nuclear resonance fluorescence experiments using the γELBE bremsstrahlung facility at Helmholtz-Zentrum Dresden-Rossendorf and the HIγS facility at Triangle Universities Nuclear Laboratory Durham. The systematic study gained new information about the influence of the neutron excess as well as of nuclear deformation on the strength in the region of the pygmy dipole resonance. The results are compared with those obtained for the chain of molybdenum isotopes and with predictions of a random-phase approximation in a deformed basis. It turned out that the effect of nuclear deformation plays a minor role compared with the one caused by neutron excess. A global parametrization of the strength in terms of neutron and proton numbers allowed us to derive a formula capable of predicting the summed E1 strengths in the pygmy region for a wide mass range of nuclides.

  6. 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.

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

    DOE PAGES

    Keiter, P. A.; Trantham, M.; Malamud, G.; ...

    2017-02-03

    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 ismore » much more complex and is a challenge to solve with many of the current radiation transport models implemented in codes. In this paper, 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. Finally, 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.« less

  8. 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. Copyright © 2010 Wiley Periodicals, Inc.

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

    NASA Astrophysics Data System (ADS)

    Simon, Nicole A.

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

  10. A comparison of traditional physical laboratory and computer-simulated laboratory experiences in relation to engineering undergraduate students' conceptual understandings of a communication systems topic

    NASA Astrophysics Data System (ADS)

    Javidi, Giti

    2005-07-01

    This study was designed to investigate an alternative to the use of traditional physical laboratory activities in a communication systems course. Specifically, this study examined whether as an alternative, computer simulation is as effective as physical laboratory activities in teaching college-level electronics engineering education students about the concepts of signal transmission, modulation and demodulation. Eighty undergraduate engineering students participated in the study, which was conducted at a southeastern four-year university. The students were randomly assigned to two groups. The groups were compared on understanding the concepts, remembering the concepts, completion time of the lab experiments and perception toward the laboratory experiments. The physical group's (n = 40) treatment was to conduct laboratory experiments in a physical laboratory. The students in this group used equipment in a controlled electronics laboratory. The Simulation group's (n = 40) treatment was to conduct similar experiments in a PC laboratory. The students in this group used a simulation program in a controlled PC lab. At the completion of the treatment, scores on a validated conceptual test were collected once after the treatment and again three weeks after the treatment. Attitude surveys and qualitative study were administered at the completion of the treatment. The findings revealed significant differences, in favor of the simulation group, between the two groups on both the conceptual post-test and the follow-up test. The findings also revealed significant correlation between simulation groups' attitude toward the simulation program and their post-test scores. Moreover, there was a significant difference between the two groups on their attitude toward their laboratory experience in favor of the simulation group. In addition, there was significant difference between the two groups on their lab completion time in favor of the simulation group. At the same time, the

  11. The dynamics of magma ascent in the crust: Characterising fluid flow and host-rock deformation using scaled analogue experiments

    NASA Astrophysics Data System (ADS)

    Kavanagh, Janine; Dennis, David

    2015-04-01

    We present the results from a series of analogue experiments that use gelatine injected by water to study magma ascent dynamics in the crust. Gelatine is a viscoelastic material that displays predominantly elastic deformation when used at low temperatures (5-10 °C) and mid-to-low concentrations (2-5 wt%). To study dyke propagation we have used a combination of Particle Image Velocimentry (PIV) and Digital Image Correlation (DIC) to characterise the dynamics of fluid flow within the intrusion and contemporaneous deformation of the host gelatine. Experiments are prepared by filling a 40 cm x 40 cm x 30 cm clear-Perspex tank with a gelatine mixture that has been seeded with neutrally buoyant fluorescent particles. Water, also seeded with tracer particles, is then injected into the solid gelatine from below under a constant flux or constant head pressure. This causes a vertical penny-shaped crack (dyke) to propagate through the gelatine and erupt at the surface. During the experiment, a vertical high-power laser sheet positioned along the centre of the tank is triggered to illuminate the seeding particles with short intense pulses, and two Dantec CCD cameras record successive images. Using PIV and DIC, vector fields of fluid flow within the intrusion and strain within the gelatine host is calculated by cross-correlation between successive images at a defined time interval. The experiments indicate that, prior to eruption, dyke propagation is characterised by rapid centralised and upwards fluid flow with accompanying downwards motion at the intrusion margin. Deformation of the gelatine solid is focused at a small head region, with the tail remaining relatively static as the dyke grows. Upon eruption, rapid centralised fluid evacuation occurs with contemporaneous contraction of the dyke and relaxation of the host gelatine. Models that can couple fluid dynamics and host deformation during magma ascent and eruption will make an important step towards improving our

  12. 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…

  13. 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)

  14. 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…

  15. Deformation modes in an Icelandic basalt: From brittle failure to localized deformation bands

    NASA Astrophysics Data System (ADS)

    Adelinet, M.; Fortin, J.; Schubnel, A.; Guéguen, Y.

    2013-04-01

    According to the stress state, deformation mode observed in rocks may be very different. Even in the brittle part of the crust a differential stress can induce shear failure but also localized compacting deformation, such as compaction bands in porous sedimentary rocks. The mode of deformation controls many hydrodynamic factors, such as permeability and porosity. We investigate in this paper two different modes of deformation in an Icelandic basalt by using laboratory seismological tools (elastic waves and acoustic emissions) and microstructural observations. First of all, we show that at low effective confining pressure (Peff = 5 MPa) an axial loading induces a shear failure in the basalt with an angle of about 30° with respect to the main stress direction. On the contrary, at high effective confining pressure (Peff ≥ 75 MPa and more) an increase of the axial stress induces a localization of the deformation in the form of subhorizontal bands again with respect to the main stress direction. In this second regime, focal mechanisms of the acoustic emissions reveal an important number of compression events suggesting pore collapse mechanisms. Microstructural observations confirm this assumption. Similar compaction structures are usually obtained for porous sedimentary rocks (20-25%). However, the investigated basalt has an initial total porosity of only about 10% so that compaction structures were not expected. The pore size and the ratio of pore to grain size are likely to be key factors for the particular observed mechanical behavior.

  16. Spiderweb deformation induced by electrostatically charged insects

    PubMed Central

    Ortega-Jimenez, Victor Manuel; Dudley, Robert

    2013-01-01

    Capture success of spider webs has been associated with their microstructure, ornamentation, and wind-induced vibrations. Indirect evidence suggests that statically charged objects can attract silk thread, but web deformations induced by charged insects have not yet been described. Here, we show under laboratory conditions that electrostatically charged honeybees, green bottle flies, fruit flies, aphids, and also water drops falling near webs of cross-spiders (Araneus diadematus) induce rapid thread deformation that enhances the likelihood of physical contact, and thus of prey capture. PMID:23828093

  17. EXPERIMENTAL EVALUATION OF DEFORMATION AND CONSTRAINT CHARACTERISTICS IN PRECRACKED CHARPY AND OTHER THREE-POINT BEND SPECIMENS

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nanstad, Randy K; Sokolov, Mikhail A; Merkle, John Graham

    2007-01-01

    To enable determination of the fracture toughness reference temperature, T0, with reactor pressure vessel surveillance specimens, the precracked Charpy (PCVN) three-point bend, SE(B), specimen is of interest. Compared with the 25-mm (1 in.) thick compact, 1TC(T), specimen, tests with the PCVN specimen (10x10x55 mm) have resulted in T0 temperatures as much as 40 XC lower (a so-called specimen bias effect). The Heavy-Section Steel Irradiation (HSSI) Program at Oak Ridge National Laboratory developed a two-part project to evaluate the C(T) versus PCVN differences, (1) calibration experiments concentrating on test practices, and (2) a matrix of transition range tests with various specimenmore » geometries and sizes, including 1T SE(B) and 1TC(T). The test material selected was a plate of A533 grade B class 1 steel. The calibration experiments included assessment of the computational validity of J-integral determinations, while the constraint characteristics of various specimen types and sizes were evaluated using key curves and notch strength determinations. The results indicate that J-integral solutions for the small PCVN specimen are comparable in terms of J-integral validity with 1T bend specimens. Regarding constraint evaluations, Phase I deformation is defined where plastic deformation is confined to crack tip plastic zone development, whereas Phase II deformation is defined where plastic hinging deformation develops. In Phase II deformation, the 0.5T SE(B) B B specimen (slightly larger than the PCVN specimen) consistently showed the highest constraint of all SE(B) specimens evaluated for constraint comparisons. The PCVN specimen begins the Phase II type of deformation at relatively low KR levels, with the result that KJc values above about 70 MPa m from precracked Charpy specimens are under extensive plastic hinging deformation.« less

  18. Laboratory volcano geodesy

    NASA Astrophysics Data System (ADS)

    Færøvik Johannessen, Rikke; Galland, Olivier; Mair, Karen

    2014-05-01

    Magma transport in volcanic plumbing systems induces surface deformation, which can be monitored by geodetic techniques, such as GPS and InSAR. These geodetic signals are commonly analyzed through geodetic models in order to constrain the shape of, and the pressure in, magma plumbing systems. These models, however, suffer critical limitations: (1) the modelled magma conduit shapes cannot be compared with the real conduits, so the geodetic models cannot be tested nor validated; (2) the modelled conduits only exhibit shapes that are too simplistic; (3) most geodetic models only account for elasticity of the host rock, whereas substantial plastic deformation is known to occur. To overcome these limitations, one needs to use a physical system, in which (1) both surface deformation and the shape of, and pressure in, the underlying conduit are known, and (2) the mechanical properties of the host material are controlled and well known. In this contribution, we present novel quantitative laboratory results of shallow magma emplacement. Fine-grained silica flour represents the brittle crust, and low viscosity vegetable oil is an analogue for the magma. The melting temperature of the oil is 31°C; the oil solidifies in the models after the end of the experiments. At the time of injection the oil temperature is 50°C. The oil is pumped from a reservoir using a volumetric pump into the silica flour through a circular inlet at the bottom of a 40x40 cm square box. The silica flour is cohesive, such that oil intrudes it by fracturing it, and produces typical sheet intrusions (dykes, cone sheets, etc.). During oil intrusion, the model surface deforms, mostly by doming. These movements are measured by an advanced photogrammetry method, which uses 4 synchronized fixed cameras that periodically image the surface of the model from different angles. We apply particle tracking method to compute the 3D ground deformation pattern through time. After solidification of the oil, the

  19. 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)

  20. 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.

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  2. Deformation of the Batestown till of the Lake Michigan lobe, Laurentide ice sheet

    USGS Publications Warehouse

    Thomason, J.F.; Iverson, N.R.

    2009-01-01

    Deep, pervasive shear deformation of the bed to high strains (>100) may have been primarily responsible for flow and sediment transport of the Lake Michigan lobe of the Laurentide ice sheet. To test this hypothesis, we sampled at 0.2 m increments a basal till from one advance of the lobe (Batestown till) along vertical profiles and measured fabrics due to both anisotropy of magnetic susceptibility and sand-grain preferred orientation. Unlike past fabric studies, interpretations were guided by results of laboratory experiments in which this till was deformed in simple shear to high strains. Fabric strengths indicate that more than half of the till sampled has a <5% probability of having been sheared to moderate strains (7-30). Secular changes in fabric azimuth over the thickness of the till, probably due to changing ice-flow direction as the lobe receded, indicate that the bed accreted with time and that the depth of deformation of the bed did not exceed a few decimeters. Orientations of principal magnetic susceptibilities show that the state of strain was commonly complex, deviating from bed-parallel simple shear. Deformation is inferred to have been focused in shallow, temporally variable patches during till deposition from ice.

  3. Syn-deformational features of Carlin-type Au deposits

    USGS Publications Warehouse

    Peters, S.G.

    2004-01-01

    Syn-deformational ore deposition played an important role in some Carlin-type Au deposits according to field and laboratory evidence, which indicates that flow of Au-bearing fluids was synchronous with regional-scale deformation events. Gold-related deformation events linked to ore genesis were distinct from high-level, brittle deformation that is typical of many epithermal deposits. Carlin-type Au deposits, with brittle-ductile features, most likely formed during tectonic events that were accompanied by significant fluid flow. Interactive deformation-fluid processes involved brittle-ductile folding, faulting, shearing, and gouge development that were focused along illite-clay and dissolution zones caused by hydrothermal alteration. Alteration along these deformation zones resulted in increased porosity and enhancement of fluid flow, which resulted in decarbonated, significant dissolution, collapse, and volume and mass reduction. Carlin-type Au deposits commonly are hosted in Paleozoic and Mesozoic sedimentary rocks (limestone, siltstone, argillite, shale, and quartzite) on the margins of cratons. The sedimentary basins containing the host rocks underwent tectonic events that influenced the development of stratabound, structurally controlled orebodies. Published by Elsevier Ltd.

  4. The strain path dependence of plastic deformation response of AA5754: Experiment and modeling

    NASA Astrophysics Data System (ADS)

    Pham, Minh-Son; Hu, Lin; Iadicola, Mark; Creuziger, Adam; Rollett, Anthony D.

    2013-12-01

    This work presents modeling of experiments on a balanced biaxial (BB) pre-strained AA5754 alloy, subsequently reloaded uniaxially along the rolling direction and transverse direction. The material exhibits a complex plastic deformation response during the change in strain path due to 1) crystallographic texture, 2) aging (interactions between dislocations and Mg atoms) and 3) recovery (annihilation and re-arrangement of dislocations). With a BB prestrain of about 5 %, the aging process is dominant, and the yield strength for uniaxially deformed samples is observed to be higher than the flow stress during BB straining. The strain hardening rate after changing path is, however, lower than that for pre-straining. Higher degrees of pre-straining make the dynamic recovery more active. The dynamic recovery at higher strain levels compensates for the aging effect, and results in: 1) a reduction of the yield strength, and 2) an increase in the hardening rate of re-strained specimens along other directions. The yield strength of deformed samples is further reduced if these samples are left at room temperature to let static recovery occur. The synergistic influences of texture condition, aging and recovery processes on the material response make the modeling of strain path dependence of mechanical behavior of AA5754 challenging. In this study, the influence of crystallographic texture is taken into account by incorporating the latent hardening into a visco-plastic self-consistent model. Different strengths of dislocation glide interaction models in 24 slip systems are used to represent the latent hardening. Moreover, the aging and recovery effects are also included into the latent hardening model by considering strong interactions between dislocations and dissolved atom Mg and the microstructural evolution. These microstructural considerations provide a powerful capability to successfully describe the strain path dependence of plastic deformation behavior of AA5754.

  5. 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.

  6. Acoustic Emission of Deformation Twinning in Magnesium

    PubMed Central

    Mo, Chengyang; Wisner, Brian; Cabal, Mike; Hazeli, Kavan; Ramesh, K. T.; El Kadiri, Haitham; Al-Samman, Talal; Molodov, Konstantin D.; Molodov, Dmitri A.; Kontsos, Antonios

    2016-01-01

    The Acoustic Emission of deformation twinning in Magnesium is investigated in this article. Single crystal testing with combined full field deformation measurements, as well as polycrystalline testing inside the scanning electron microscope with simultaneous monitoring of texture evolution and twin nucleation were compared to testing at the laboratory scale with respect to recordings of Acoustic Emission activity. Single crystal testing revealed the formation of layered twin boundaries in areas of strain localization which was accompanied by distinct changes in the acoustic data. Testing inside the microscope directly showed twin nucleation, proliferation and growth as well as associated crystallographic reorientations. A post processing approach of the Acoustic Emission activity revealed the existence of a class of signals that appears in a strain range in which twinning is profuse, as validated by the in situ and ex situ microscopy observations. Features extracted from such activity were cross-correlated both with the available mechanical and microscopy data, as well as with the Acoustic Emission activity recorded at the laboratory scale for similarly prepared specimens. The overall approach demonstrates that the method of Acoustic Emission could provide real time volumetric information related to the activation of deformation twinning in Magnesium alloys, in spite of the complexity of the propagation phenomena, the possible activation of several deformation modes and the challenges posed by the sensing approach itself when applied in this type of materials evaluation approach. PMID:28773786

  7. Two LANL laboratory astrophysics experiments

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  9. Enhancing the Student Experience of Laboratory Practicals through Digital Video Guides

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  10. 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…

  11. A laser profilometry technique for monitoring fluvial dike breaching in laboratory experiments

    NASA Astrophysics Data System (ADS)

    Dewals, Benjamin; Rifai, Ismail; Erpicum, Sébastien; Archambeau, Pierre; Violeau, Damien; Pirotton, Michel; El kadi Abderrezzak, Kamal

    2017-04-01

    A challenging aspect for experimental modelling of fluvial dike breaching is the continuous monitoring of the transient breach geometry. In dam breaching cases induced by flow overtopping over the whole breach crest (plane erosion), a side view through a glass wall is sufficient to monitor the breach formation. This approach can be extended for 3D dam breach tests (spatial erosion) if the glass wall is located along the breach centreline. In contrast, using a side view does not apply for monitoring fluvial dike breaching, because the breach is not symmetric in this case. We present a non-intrusive, high resolution technique to record the breach development in experimental models of fluvial dikes by means of a laser profilometry (Rifai et al. 2016). Most methods used for monitoring dam and dike breaching involve the projection of a pattern (fringes, grid) on the dam or dike body and the analysis of its deformation on images recorded during the breaching (e.g., Pickert et al. 2011, Frank and Hager 2014). A major limitation of these methods stems from reflection on the water surface, particularly in the vicinity of the breach where the free surface is irregular and rippled. This issue was addressed by Spinewine et al. (2004), who used a single laser sheet so that reflections on the water surface were strongly limited and did not hamper the accurate processing of each image. We have developed a similar laser profilometry technique tailored for laboratory experiments on fluvial dike breaching. The setup is simple and relatively low cost. It consists of a digital video camera (resolution of 1920 × 1080 pixels at 60 frames per second) and a swiping red diode 30 mW laser that enables the projection of a laser sheet over the dike body. The 2D image coordinates of each deformed laser profile incident on the dike are transformed into 3D object coordinates using the Direct Linear Transformation (DLT) algorithm. All 3D object coordinates computed over a swiping cycle of the

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

    ERIC Educational Resources Information Center

    Tiwari, Rajiv; Singh, Khilawan

    2011-01-01

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

  13. 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…

  14. 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.

  15. Calibration Device Designed for proof ring used in SCC Experiment

    NASA Astrophysics Data System (ADS)

    Hu, X. Y.; Kang, Z. Y.; Yu, Y. L.

    2017-11-01

    In this paper, a calibration device for proof ring used in SCC (Stress Corrosion Cracking) experiment was designed. A compact size loading device was developed to replace traditional force standard machine or a long screw nut. The deformation of the proof ring was measured by a CCD (Charge-Coupled Device) during the calibration instead of digital caliper or a dial gauge. The calibration device was verified at laboratory that the precision of force loading is ±0.1% and the precision of deformation measurement is ±0.002mm.

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

    NASA Technical Reports Server (NTRS)

    1972-01-01

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

  17. Deformation-induced crystallographic-preferred orientation of hcp-iron: An experimental study using a deformation-DIA apparatus

    NASA Astrophysics Data System (ADS)

    Nishihara, Yu; Ohuchi, Tomohiro; Kawazoe, Takaaki; Seto, Yusuke; Maruyama, Genta; Higo, Yuji; Funakoshi, Ken-ichi; Tange, Yoshinori; Irifune, Tetsuo

    2018-05-01

    Shear and uniaxial deformation experiments on hexagonal close-packed iron (hcp-Fe) was conducted using a deformation-DIA apparatus at a pressure of 13-17 GPa and a temperature of 723 K to determine its deformation-induced crystallographic-preferred orientation (CPO). Development of the CPO in the deforming sample is determined in-situ based on two-dimensional X-ray diffraction using monochromatic synchrotron X-rays. In the shear deformation geometry, the <0001> and < 11 2 bar 0 > axes gradually align to be sub-parallel to the shear plane normal and shear direction, respectively, from the initial random texture. In the uniaxial compression and tensile geometry, the <0001> and < 11 2 bar 0 > axes, respectively, gradually align along the direction of the uniaxial deformation axis. These results suggest that basal slip (0001) < 11 2 bar 0 > is the dominant slip system in hcp-Fe under the studied deformation conditions. The P-wave anisotropy for a shear deformed sample was calculated using elastic constants at the inner core condition by recent ab-initio calculations. Strength of the calculated anisotropy was comparable to or higher than axisymmetric anisotropy in Earth's inner core.

  18. Micromechanisms of deformation in shales

    NASA Astrophysics Data System (ADS)

    Bonnelye, A.; Gharbi, H.; Hallais, S.; Dimanov, A.; Bornert, M.; Picard, D.; Mezni, M.; Conil, N.

    2017-12-01

    One of the envisaged solutions for nuclear wastes disposal is underground repository in shales. For this purpose, the Callovo Oxfordian (Cox) argillaceous formation is extensively studied. The hydro-mechanical behavior of the argillaceous rock is complex, like the multiphase and multi-scale structured material itself. The argilaceous matrix is composed of interstratified illite-smectite particles, it contains detritic quartz and calcite, accessory pyrite, and the rock porosity ranges from micrometre to nanometre scales. Besides the bedding anisotropy, structural variabilities exist at all scales, from the decametric-metric scales of the geological formation to the respectively millimetric and micrometric scales of the aggregates of particles and clay particles Our study aims at understanding the complex mechanisms which are activated at the micro-scale and are involved in the macroscopic inelastic deformation of such a complex material. Two sets of experiments were performed, at two scales on three bedding orientations (90°, 45° and 0°). The first set was dedicated to uniaxial deformation followed with an optical set-up with a pixel resolution of 0.55µm. These experiments allowed us to see the fracture propagation with different patterns depending on the bedding orientation. For the second set of experiments, an experimental protocol was developed in order to perform uniaxial deformation experiment at controlled displacement rate, inside an environmental scanning electron microscope (ESEM), under controlled relative humidity, in order to preserve as much as possible the natural state of saturation of shales. We aimed at characterizing the mechanical anisotropy and the mechanisms involved in the deformation, with an image resolution below the micormeter. The observed sample surfaces were polished by broad ion beam in order to reveal the fine microstructures of the argillaceous matrix. In both cases, digital images were acquired at different loading stages during

  19. Virtual Patterson Experiment - A Way to Access the Rheology of Aggregates and Melanges

    NASA Astrophysics Data System (ADS)

    Delannoy, Thomas; Burov, Evgueni; Wolf, Sylvie

    2014-05-01

    Understanding the mechanisms of lithospheric deformation requires bridging the gap between human-scale laboratory experiments and the huge geological objects they represent. Those experiments are limited in spatial and time scale as well as in choice of materials (e.g., mono-phase minerals, exaggerated temperatures and strain rates), which means that the resulting constitutive laws may not fully represent real rocks at geological spatial and temporal scales. We use the thermo-mechanical numerical modelling approach as a tool to link both experiments and nature and hence better understand the rheology of the lithosphere, by enabling us to study the behavior of polymineralic aggregates and their impact on the localization of the deformation. We have adapted the large strain visco-elasto-plastic Flamar code to allow it to operate at all spatial and temporal scales, from sub-grain to geodynamic scale, and from seismic time scales to millions of years. Our first goal was to reproduce real rock mechanics experiments on deformation of mono and polymineralic aggregates in Patterson's load machine in order to deepen our understanding of the rheology of polymineralic rocks. In particular, we studied in detail the deformation of a 15x15 mm mica-quartz sample at 750 °C and 300 MPa. This mixture includes a molten phase and a solid phase in which shear bands develop as a result of interactions between ductile and brittle deformation and stress concentration at the boundaries between weak and strong phases. We used digitized x-ray scans of real samples as initial configuration for the numerical models so the model-predicted deformation and stress-strain behavior can match those observed in the laboratory experiment. Analyzing the numerical experiments providing the best match with the press experiments and making other complementary models by changing different parameters in the initial state (strength contrast between the phases, proportions, microstructure, etc.) provides a

  20. 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.

  1. 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.

  2. 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.

  3. Nuclear astrophysics at Gran Sasso Laboratory: the LUNA experiment

    NASA Astrophysics Data System (ADS)

    Cavanna, Francesca

    2018-05-01

    LUNA is an experimental approach for the study of nuclear fusion reactions based on an underground accelerator laboratory. Aim of the experiment is the direct measurement of the cross section of nuclear reactions relevant for stellar and primordial nucleosynthesis. In the following the latest results and the future goals will be presented.

  4. Coupling fluid dynamics and host-rock deformation associated with magma intrusion in the crust: Insights from analogue experiments

    NASA Astrophysics Data System (ADS)

    Kavanagh, J. L.; Dennis, D. J.

    2014-12-01

    Models of magma ascent in the crust tend to either consider the dynamics of fluid flow within intrusions or the associated host-rock deformation. However, these processes are coupled in nature, and so to develop a more complete understanding of magma ascent dynamics in the crust both need to be taken into account. We present a series of gelatine analogue experiments that use both Particle Image Velocimentry (PIV) and Digital Image Correlation (DIC) techniques to characterise the dynamics of fluid flow within intrusions and to quantify the associated deformation of the intruded media. Experiments are prepared by filling a 40x40x30 cm3 clear-Perspex tank with a low-concentration gelatine mixture (2-5 wt%) scaled to be of comparable stiffness to crustal strata. Fluorescent seeding particles are added to the gelatine mixture during its preparation and to the magma analogue prior to injection. Two Dantec CCD cameras are positioned outside the tank and a vertical high-power laser sheet positioned along the centre line is triggered to illuminate the seeding particles with short intense pulses. Dyed water (the magma analogue) injected into the solid gelatine from below causes a vertically propagating penny-shaped crack (dike) to form. Incremental and cumulative displacement vectors are calculated by cross-correlation between successive images at a defined time interval. Spatial derivatives map the fluid flow within the intrusion and associated strain and stress evolution of the host, both during dike propagation and on to eruption. As the gelatine deforms elastically at the experimental conditions, strain calculations correlate with stress. Models which couple fluid dynamics and host deformation make an important step towards improving our understanding of the dynamics of magma transport through the crust and to help constrain the tendency for eruption.

  5. Clinical experience of repair of pectus excavatum and carinatum deformities.

    PubMed

    Oncel, Murat; Tezcan, Bekir; Akyol, Kazim Gurol; Dereli, Yüksel; Sunam, Güven Sadi

    2013-09-01

    We present the results of surgical correction of pectus excavatum (PE) and pectus carinatum (PC) deformities in adults, and also report a new method of sternal support used in surgery for PE deformities. We present the results of 77 patients between the ages of 10 and 29 years (mean 17) with PE (n = 46) or PC (n = 31) deformities undergoing corrective surgery from 2004 to 2011, using the Ravitch repair method. Symptoms of the patients included chest pain (15%) and tachycardia (8%). Three patients underwent repair of recurrent surgical conditions. All of the patients with dyspnoea with exercise experienced marked improvement at five months post operation. Complications included pneumothorax in 5.1% (n = 4), haemothorax in 2.6% (n = 2), chest discomfort in 57% (n = 44), pleural effusion in 2.6% (n = 2), and sternal hypertrophic scar in 27% (n = 21) of patients. Mean hospitalisation was eight days. Pain was mild and intravenous analgesics were used for a mean of four days. There were no deaths. Results after surgical correction were very good or excellent in 62 patients (80%) at a mean follow up of three years. Three patients had recurrent PE and were repaired with the Nuss procedure. In three patients who underwent the Ravitch procedure, a stainless steel bar was used for sternal support instead of Kirschner wire. Pectus deformities may be repaired with no mortality, low morbidity, very good cosmetic results and improvement in cardiological and respiratory symptoms.

  6. Experiments to assess preheat in blast-wave-drive instability experiments

    NASA Astrophysics Data System (ADS)

    Krauland, Christine; Drake, Paul; Kuranz, Carolyn; Grosskopf, Michael; Boehly, Tom

    2009-11-01

    The use of multi-kilojoule, ns lasers to launch shock waves has become a standard method for initiating hydrodynamic experiments in Laboratory Astrophysics. However, the intense laser ablation that creates moving plasma also leads to the production of unwanted energetic x-rays and suprathermal electrons, both of which can be sources of material preheating. In principle, this preheat can alter the conditions of the experimental setup prior to the occurrence of the intended dynamics. At the University of Michigan, ongoing Rayleigh-Taylor instability experiments are defined by precise initial conditions, and potential deformation due to preheat could greatly affect their accuracy. An experiment devised and executed in an attempt to assess the preheat in this specific case will be presented, along with the quantitative analysis of the data obtained and comparison with 2D simulations.

  7. Evolution of the viscosity of Earth's upper mantle: Grain-boundary sliding and the role of microstructure in olivine deformation

    NASA Astrophysics Data System (ADS)

    Hansen, Lars N.

    Many features of plate tectonics cannot be explained with standard rheological models of the upper mantle. In particular, the localization of deformation at plate boundaries requires the viscosity of the constituent rocks to evolve spatially and temporally. Such rheological complexity may arise from changing microstructural state variables (e.g., grain size and crystallographic-fabric strength), but the degree to which microstructure contributes to the evolution of viscosity is unclear given our current understanding of deformation mechanisms in mantle minerals. Dislocation-accommodated grain-boundary sliding (GBS) is a potentially critical mechanism for localizing deformation in olivine because it imparts a sensitivity of the viscosity to the state of the microstructure while simultaneously providing mechanisms for changing the microstructure. However, many details of GBS in olivine are currently unknown including 1) the magnitude of the sensitivity of strain rate to crystallographic fabric and grain size, 2) the strength of the crystallographic fabrics produced, and 3) the anisotropy in viscosity of polycrystalline aggregates. Detailed knowledge of these unknowns is necessary to assess the importance of microstructural evolution in the operation of plate tectonics. This dissertation investigates the details of GBS in olivine through four sets of laboratory-based experiments. In Chapter 2, triaxial compressive creep experiments on aggregates of San Carlos olivine are used to develop a flow law for olivine deforming by GBS. Extrapolations of strain rate to geological conditions using the derived flow law indicate that GBS is the dominant deformation mechanism throughout the uppermost mantle. Crystallographic fabrics observed in deformed samples are consistent with upper-mantle seismic anisotropy. In Chapter 3, torsion experiments on iron-rich olivine are used to determine the rheological behavior of olivine deforming by GBS at large strains. The sensitivity of the

  8. Solute and heat transport model of the Henry and Hilleke laboratory experiment

    USGS Publications Warehouse

    Langevin, C.D.; Dausman, A.M.; Sukop, M.C.

    2010-01-01

    SEAWAT is a coupled version of MODFLOW and MT3DMS designed to simulate variable-density ground water flow and solute transport. The most recent version of SEAWAT, called SEAWAT Version 4, includes new capabilities to represent simultaneous multispecies solute and heat transport. To test the new features in SEAWAT, the laboratory experiment of Henry and Hilleke (1972) was simulated. Henry and Hilleke used warm fresh water to recharge a large sand-filled glass tank. A cold salt water boundary was represented on one side. Adjustable heating pads were used to heat the bottom and left sides of the tank. In the laboratory experiment, Henry and Hilleke observed both salt water and fresh water flow systems separated by a narrow transition zone. After minor tuning of several input parameters with a parameter estimation program, results from the SEAWAT simulation show good agreement with the experiment. SEAWAT results suggest that heat loss to the room was more than expected by Henry and Hilleke, and that multiple thermal convection cells are the likely cause of the widened transition zone near the hot end of the tank. Other computer programs with similar capabilities may benefit from benchmark testing with the Henry and Hilleke laboratory experiment. Journal Compilation ?? 2009 National Ground Water Association.

  9. Deformation of olivine during phase transformation to wadsleyite

    NASA Astrophysics Data System (ADS)

    Mohiuddin, A.; Girard, J.; Karato, S. I.

    2017-12-01

    The strength of subducting slabs in the transition zone is critical in controlling the style of mantle convection. However, rheological properties of a subducted slab are elusive: low temperatures of a slab would make slabs strong, but in many regions there is evidence of intense deformation of slabs in the transition zone. One potential cause of intense deformation of subducting slabs is grain size reduction and accompanied microstructural changes during phase transformation of olivine to its higher-pressure polymorphs. There have been no experimental studies to quantify the influence of grain-size evolution. In addition to grain size reduction, distribution of small grains during phase transformation governs the degree of weakening during phase transformation (for e.g. load bearing framework vs. inter-connected layered framework). We conducted laboratory studies on the size and spatial distribution of new grains of wadsleyite after the transformation from olivine. Our results under static conditions show that an interconnected microstructure develops during the initial stage of phase transformation and that the grain size of the interconnected phase (wadsleyite) depends on the temperature at which the phase transformation occurs (smaller grains at lower temperatures). Development of an interconnected microstructure may lead to strain localization in the weaker phase, i.e. the fine-grained interconnected network accommodates most of the strain and therefore weakening of the entire composite. We will test this model through a series of two synchrotron in-situ deformation experiments: (i) Olivine aggregate will be deformed during slow pressure increase from deep upper mantle pressure ( 10 GPa) to transition zone pressure ( 15 GPa) at a given temperature simulating the deformation of a slab penetrating into the transition zone (ii) olivine is partially transformed to wadsleyite in a multi anvil apparatus at Yale and will be deformed within the stability field where

  10. Virtual geotechnical laboratory experiments using a simulator

    NASA Astrophysics Data System (ADS)

    Penumadu, Dayakar; Zhao, Rongda; Frost, David

    2000-04-01

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

  11. Guided-inquiry laboratory experiments to improve students' analytical thinking skills

    NASA Astrophysics Data System (ADS)

    Wahyuni, Tutik S.; Analita, Rizki N.

    2017-12-01

    This study aims to improve the experiment implementation quality and analytical thinking skills of undergraduate students through guided-inquiry laboratory experiments. This study was a classroom action research conducted in three cycles. The study has been carried out with 38 undergraduate students of the second semester of Biology Education Department of State Islamic Institute (SII) of Tulungagung, as a part of Chemistry for Biology course. The research instruments were lesson plans, learning observation sheets and undergraduate students' experimental procedure. Research data were analyzed using quantitative-descriptive method. The increasing of analytical thinking skills could be measured using gain score normalized and statistical paired t-test. The results showed that guided-inquiry laboratory experiments model was able to improve both the experiment implementation quality and the analytical thinking skills. N-gain score of the analytical thinking skills was increased, in spite of just 0.03 with low increase category, indicated by experimental reports. Some of undergraduate students have had the difficulties in detecting the relation of one part to another and to an overall structure. The findings suggested that giving feedback the procedural knowledge and experimental reports were important. Revising the experimental procedure that completed by some scaffolding questions were also needed.

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

    PubMed Central

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

    1988-01-01

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

  13. The deformation of gum metal under nanoindentation and sub-micron pillar compression

    NASA Astrophysics Data System (ADS)

    Withey, Elizabeth Ann

    Reaching ideal strength has proven to be difficult in most materials. Dislocation slip, phase transformations, twinning, and fracture all tend to occur at stresses well below the ideal strength of a material. Only on very small scales has it been possible to approach ideal strength. Thus, it was of great interest when a set of beta-Ti alloys, Gum Metal, were found to have a bulk yield strength close to half of its ideal strength. However, some recent studies have questioned the reliability of this claim. Several studies have suggested Gum Metal deforms by dislocation slip. Others have suggested the possibility of transformation-induced plasticity. The present study was undertaken in order to help clarify if and how Gum Metal can reach ideal strength. Two different experiments, ex situ nanoindentation and quantitative in situ nanopillar compression in a transmission electron microscope to correlate real-time deformation behavior, were performed on a single composition of Gum Metal, Ti-23Nb-0.7Ta-2Zr-1.20 at. %, obtained from Toyota Central R&D Laboratories. Nanoindented specimens were thinned from the bottom surface until the pits of multiple indentations became electron-transparent allowing for qualitative analysis of the deformation microstructure in both fully cold-worked and solution-treated specimens. Real-time load-displacement behavior from the nanopillar compression tests was correlated with real-time video recorded during each compression to determine both the compressive strength of each pillar and the timing and strengths of different deformation behaviors observed. Combining the results from both experiments provided several important conclusions. First, Gum Metal approaches and can attain ideal strength in nanopillars regardless of processing condition. While dislocations exist in Gum Metal, they can be tightly pinned by obstacles with spacing less than ˜20 nm, which should inhibit their motion at strengths below the ideal shear strength. The plastic

  14. Deformable human body model development

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wray, W.O.; Aida, T.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). A Deformable Human Body Model (DHBM) capable of simulating a wide variety of deformation interactions between man and his environment has been developed. The model was intended to have applications in automobile safety analysis, soldier survivability studies and assistive technology development for the disabled. To date, we have demonstrated the utility of the DHBM in automobile safety analysis and are currently engaged in discussions with the U.S. military involving two additional applications. More specifically, the DHBM has beenmore » incorporated into a Virtual Safety Lab (VSL) for automobile design under contract to General Motors Corporation. Furthermore, we have won $1.8M in funding from the U.S. Army Medical Research and Material Command for development of a noninvasive intracranial pressure measurement system. The proposed research makes use of the detailed head model that is a component of the DHBM; the project duration is three years. In addition, we have been contacted by the Air Force Armstrong Aerospace Medical Research Laboratory concerning possible use of the DHBM in analyzing the loads and injury potential to pilots upon ejection from military aircraft. Current discussions with Armstrong involve possible LANL participation in a comparison between DHBM and the Air Force Articulated Total Body (ATB) model that is the current military standard.« less

  15. 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.

  16. 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: n e ≈ n i ~ 10¹⁶ cm⁻³, T e ≈ T i ≈ 1.4 eV, V jet ≈ 30–100 km/s, mean chargemore » $$\\bar{Z}$$ ≈ 1, sonic Mach number M s ≡ V jet/C s > 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

  17. Laboratory plasma physics experiments using merging supersonic plasma jets

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

    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: n e ≈ n i ~ 10¹⁶ cm⁻³, T e ≈ T i ≈ 1.4 eV, V jet ≈ 30–100 km/s, mean chargemore » $$\\bar{Z}$$ ≈ 1, sonic Mach number M s ≡ V jet/C s > 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

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

    1994-01-01

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

  19. On the potential for using immersive virtual environments to support laboratory experiment contextualisation

    NASA Astrophysics Data System (ADS)

    Machet, Tania; Lowe, David; Gütl, Christian

    2012-12-01

    This paper explores the hypothesis that embedding a laboratory activity into a virtual environment can provide a richer experimental context and hence improve the understanding of the relationship between a theoretical model and the real world, particularly in terms of the model's strengths and weaknesses. While an identified learning objective of laboratories is to support the understanding of the relationship between models and reality, the paper illustrates that this understanding is hindered by inherently limited experiments and that there is scope for improvement. Despite the contextualisation of learning activities having been shown to support learning objectives in many fields, there is traditionally little contextual information presented during laboratory experimentation. The paper argues that the enhancing laboratory activity with contextual information affords an opportunity to improve students' understanding of the relationship between the theoretical model and the experiment (which is effectively a proxy for the complex real world), thereby improving their understanding of the relationship between the model and reality. The authors propose that these improvements can be achieved by setting remote laboratories within context-rich virtual worlds.

  20. Transitioning EEG experiments away from the laboratory using a Raspberry Pi 2.

    PubMed

    Kuziek, Jonathan W P; Shienh, Axita; Mathewson, Kyle E

    2017-02-01

    Electroencephalography (EEG) experiments are typically performed in controlled laboratory settings to minimise noise and produce reliable measurements. These controlled conditions also reduce the applicability of the obtained results to more varied environments and may limit their relevance to everyday situations. Advances in computer portability may increase the mobility and applicability of EEG results while decreasing costs. In this experiment we show that stimulus presentation using a Raspberry Pi 2 computer provides a low cost, reliable alternative to a traditional desktop PC in the administration of EEG experimental tasks. Significant and reliable MMN and P3 activity, typical event-related potentials (ERPs) associated with an auditory oddball paradigm, were measured while experiments were administered using the Raspberry Pi 2. While latency differences in ERP triggering were observed between systems, these differences reduced power only marginally, likely due to the reduced processing power of the Raspberry Pi 2. An auditory oddball task administered using the Raspberry Pi 2 produced similar ERPs to those derived from a desktop PC in a laboratory setting. Despite temporal differences and slight increases in trials needed for similar statistical power, the Raspberry Pi 2 can be used to design and present auditory experiments comparable to a PC. Our results show that the Raspberry Pi 2 is a low cost alternative to the desktop PC when administering EEG experiments and, due to its small size and low power consumption, will enable mobile EEG experiments unconstrained by a traditional laboratory setting. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Deformation in the mantle wedge associated with Laramide flat-slab subduction

    NASA Astrophysics Data System (ADS)

    Behr, Whitney M.; Smith, Douglas

    2016-07-01

    Laramide crustal deformation in the Rocky Mountains of the west-central United States is often considered to relate to a narrow segment of shallow subduction of the Farallon slab, but there is no consensus as to how deformation along the slab-mantle lithosphere interface was accommodated. Here we investigate deformation in mantle rocks associated with hydration and shear above the flat-slab at its contact with the base of the North American plate. The rocks we focus on are deformed, hydrated, ultramafic inclusions hosted within diatremes of the Navajo Volcanic Field in the central Colorado Plateau that erupted during the waning stages of the Laramide orogeny. We document a range of deformation textures, including granular peridotites, porphyroclastic peridotites, mylonites, and cataclasites, which we interpret to reflect different proximities to a slab-mantle-interface shear zone. Mineral assemblages and chemistries constrain deformation to hydrous conditions in the temperature range ˜550-750°C. Despite the presence of hydrous phyllosilicates in modal percentages of up to 30%, deformation was dominated by dislocation creep in olivine. The mylonites exhibit an uncommon lattice preferred orientation (LPO) in olivine, known as B-type LPO in which the a-axes are aligned perpendicular to the flow direction. The low temperature, hydrated setting in which these fabrics formed is consistent with laboratory experiments that indicate B-type LPOs form under conditions of high stress and high water contents; furthermore, the mantle wedge context of these LPOs is consistent with observations of trench-parallel anisotropy in the mantle wedge above many modern subduction zones. Differential stress magnitudes in the mylonitic rocks estimated using paleopiezometry range from 290 to 444 MPa, and calculated effective viscosities using a wet olivine flow law are on the order of 1019-1023 Pa s. The high stress magnitudes, high effective viscosities, and high strains recorded in these

  2. Investigating the dynamics of Vulcanian explosions using scaled laboratory experiments

    NASA Astrophysics Data System (ADS)

    Clarke, A. B.; Phillips, J. C.; Chojnicki, K. N.

    2005-12-01

    Laboratory experiments were conducted to investigate the dynamics of Vulcanian eruptions. A reservoir containing a mixture of water and methanol plus solid particles was pressurized and suddenly released via a rapid-release valve into a 2 ft by 2 ft by 4 ft plexiglass tank containing fresh water. Water and methanol created a light interstitial fluid to simulate buoyant volcanic gases in erupted mixtures. The duration of the subsequent experiments was not pre-determined, but instead was limited by the potential energy associated with the pressurized fluid, rather than by the volume of available fluid. Suspending liquid density was varied between 960 and 1000 kg m-3 by changing methanol concentrations from 5 to 20%. Particle size (4 & 45 microns) and concentration (1 to 5 vol%) were varied in order to change particle settling characteristics and control bulk mixture density. Variations in reservoir pressure and vent size allowed exploration of the controlling source parameters, buoyancy flux (Bo) and momentum flux (Mo). The velocity-height relationship of each experiment was documented by high-speed video, permitting classification of the laboratory flows, which ranged from long continuously accelerating jets, to starting plumes, to low-energy thermals, to collapsing fountains generating density currents. Field-documented Vulcanian explosions exhibit this same wide range of behavior (Self et al. 1979, Nature 277; Sparks & Wilson 1982, Geophys. J. R. astr. Soc. 69; Druitt et al. 2002, Geol. Soc. London, 21), demonstrating that flows obtained in the laboratory are relevant to natural systems. A generalized framework of results was defined as follows. Increasing Mo/Bo for small particles (4 microns; settling time > experiment duration) pushes the system from low-energy thermals toward high-energy, continuously accelerating jets; increasing Mo/Bo for large particles (>45 microns; settling time < experiment duration) pushes the system from a low collapsing fountain to a

  3. Experience of quality management system in a clinical laboratory in Nigeria

    PubMed Central

    Sylvester-Ikondu, Ugochukwu; Onwuamah, Chika K.; Salu, Olumuyiwa B.; Ige, Fehintola A.; Meshack, Emily; Aniedobe, Maureen; Amoo, Olufemi S.; Okwuraiwe, Azuka P.; Okhiku, Florence; Okoli, Chika L.; Fasela, Emmanuel O.; Odewale, Ebenezer. O.; Aleshinloye, Roseline O.; Olatunji, Micheal; Idigbe, Emmanuel O.

    2012-01-01

    Issues Quality-management systems (QMS) are uncommon in clinical laboratories in Nigeria, and until recently, none of the nation’s 5 349 clinical laboratories have been able to attain the certifications necessary to begin the process of attaining international accreditation. Nigeria’s Human Virology Laboratory (HVL), however, began implementation of a QMS in 2006, and in 2008 it was determined that the laboratory conformed to the requirements of ISO 9001:2000 (now 2008), making it the first diagnostic laboratory to be certified in Nigeria. The HVL has now applied for the World Health Organization (WHO) accreditation preparedness scheme. The experience of the QMS implementation process and the lessons learned therein are shared here. Description In 2005, two personnel from the HVL spent time studying quality systems in a certified clinical laboratory in Dakar, Senegal. Following this peer-to-peer technical assistance, several training sessions were undertaken by HVL staff, a baseline assessment was conducted, and processes were established. The HVL has monitored its quality indicators and conducted internal and external audits; these analyses (from 2007 to 2009) are presented herein. Lessons learned Although there was improvement in the pre-analytical and analytical indicators analysed and although data-entry errors decreased in the post-analytical process, the delay in returning laboratory test results increased significantly. There were several factors identified as causes for this delay and all of these have now been addressed except for an identified need for automation of some high-volume assays (currently being negotiated). Internal and external audits showed a trend of increasing non-conformities which could be the result of personnel simply becoming lax over time. Application for laboratory accreditation, however, could provide the renewed vigour needed to correct these non-conformities. Recommendation This experience shows that sustainability of the QMS

  4. Knowledge representation of rock plastic deformation

    NASA Astrophysics Data System (ADS)

    Davarpanah, Armita; Babaie, Hassan

    2017-04-01

    The first iteration of the Rock Plastic Deformation (RPD) ontology models the semantics of the dynamic physical and chemical processes and mechanisms that occur during the deformation of the generally inhomogeneous polycrystalline rocks. The ontology represents the knowledge about the production, reconfiguration, displacement, and consumption of the structural components that participate in these processes. It also formalizes the properties that are known by the structural geology and metamorphic petrology communities to hold between the instances of the spatial components and the dynamic processes, the state and system variables, the empirical flow laws that relate the variables, and the laboratory testing conditions and procedures. The modeling of some of the complex physio-chemical, mathematical, and informational concepts and relations of the RPD ontology is based on the class and property structure of some well-established top-level ontologies. The flexible and extensible design of the initial version of the RPD ontology allows it to develop into a model that more fully represents the knowledge of plastic deformation of rocks under different spatial and temporal scales in the laboratory and in solid Earth. The ontology will be used to annotate the datasets related to the microstructures and physical-chemical processes that involve them. This will help the autonomous and globally distributed communities of experimental structural geologists and metamorphic petrologists to coherently and uniformly distribute, discover, access, share, and use their data through automated reasoning and enhanced data integration and software interoperability.

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  6. 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.

  7. 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)

  8. The Boulby Geoscience Project Underground Research Laboratory: Initial Results of a Rock Mechanics Laboratory Testing Programme

    NASA Astrophysics Data System (ADS)

    Brain, M. J.; Petley, D. N.; Rosser, N.; Lim, M.; Sapsford, M.; Barlow, J.; Norman, E.; Williams, A.; Pybus, D.

    2009-12-01

    The Boulby Mine, which is situated on the northeast coast of England, is a major source of potash, primarily for use as a fertiliser, with a secondary product of rock salt (halite), used in highway deicing. The deposits are part of the Zechstein formation and are found at depths of between c.1100 and 1135 m below sea level. The evaporite sequence also contains a range of further lithologies, including anhydrite, dolomite and a mixed evaporate deposit. From a scientific perspective the dry, uncontaminated nature of the deposits, the range of lithologies present and the high stress conditions at the mine provide a unique opportunity to observe rock deformation in situ in varying geological and stress environments. To this end the Boulby Geoscience Project was established to examine the feasibility of developing an underground research laboratory at the mine. Information regarding the mechanical properties of the strata at the Boulby Mine is required to develop our understanding of the strength and deformation behaviour of the rock over differing timescales in response to variations in the magnitude and duration of applied stresses. As such data are currently limited, we have developed a laboratory testing programme that examines the behaviour of the deposits during the application of differential compressive stresses. We present the initial results of this testing programme here. Experiments have been carried out using a high pressure Virtual Infinite Strain (VIS) triaxial apparatus (250 kN maximum axial load; 64 MPa maximum cell pressure) manufactured by GDS Instruments. Conventional compression tests under uniaxial and triaxial conditions have been undertaken to determine the effects of axial stress application rate, axial strain rate and confining pressure on behaviour and failure mechanisms. The experimental programme also includes advanced testing into time-dependent creep behaviour under constant deviatoric stress; the effects of variations in temperature and

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

    ERIC Educational Resources Information Center

    Mirchin, Robert Douglas

    2012-01-01

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

  10. Measuring Viscoelastic Deformation with an Optical Mouse

    ERIC Educational Resources Information Center

    Ng, T. W.

    2004-01-01

    The feasibility of using an optical mouse to track the viscoelastic deformation of low-density polyethylene films that have a fixed attached load is presented. It is seen that using an optical mouse and with rudimentary experiment paraphernalia and arrangement, it is possible to get good measurements of viscoelastic deformation.

  11. Real-time laboratory exercises to test contingency plans for classical swine fever: experiences from two national laboratories.

    PubMed

    Koenen, F; Uttenthal, A; Meindl-Böhmer, A

    2007-12-01

    In order to adequately and efficiently handle outbreaks of contagious diseases such as classical swine fever (CSF), foot and mouth disease or highly pathogenic avian influenza, competent authorities and the laboratories involved have to be well prepared and must be in possession of functioning contingency plans. These plans should ensure that in the event of an outbreak access to facilities, equipment, resources, trained personnel, and all other facilities needed for the rapid and efficient eradication of the outbreak is guaranteed, and that the procedures to follow are well rehearsed. It is essential that these plans are established during 'peace-time' and are reviewed regularly. This paper provides suggestions on how to perform laboratory exercises to test preparedness and describes the experiences of two national reference laboratories for CSF. The major lesson learnt was the importance of a well-documented laboratory contingency plan. The major pitfalls encountered were shortage of space, difficulties in guaranteeing biosecurity and sufficient supplies of sterile equipment and consumables. The need for a standardised laboratory information management system, that is used by all those involved in order to reduce the administrative load, is also discussed.

  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. 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…

  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. Deformation mechanisms in experimentally deformed Boom Clay

    NASA Astrophysics Data System (ADS)

    Desbois, Guillaume; Schuck, Bernhard; Urai, Janos

    2016-04-01

    Bulk mechanical and transport properties of reference claystones for deep disposal of radioactive waste have been investigated since many years but little is known about microscale deformation mechanisms because accessing the relevant microstructure in these soft, very fine-grained, low permeable and low porous materials remains difficult. Recent development of ion beam polishing methods to prepare high quality damage free surfaces for scanning electron microscope (SEM) is opening new fields of microstructural investigation in claystones towards a better understanding of the deformation behavior transitional between rocks and soils. We present results of Boom Clay deformed in a triaxial cell in a consolidated - undrained test at a confining pressure of 0.375 MPa (i.e. close to natural value), with σ1 perpendicular to the bedding. Experiments stopped at 20 % strain. As a first approximation, the plasticity of the sample can be described by a Mohr-Coulomb type failure envelope with a coefficient of cohesion C = 0.117 MPa and an internal friction angle ϕ = 18.7°. After deformation test, the bulk sample shows a shear zone at an angle of about 35° from the vertical with an offset of about 5 mm. We used the "Lamipeel" method that allows producing a permanent absolutely plane and large size etched micro relief-replica in order to localize and to document the shear zone at the scale of the deformed core. High-resolution imaging of microstructures was mostly done by using the BIB-SEM method on key-regions identified after the "Lamipeel" method. Detailed BIB-SEM investigations of shear zones show the following: the boundaries between the shear zone and the host rock are sharp, clay aggregates and clastic grains are strongly reoriented parallel to the shear direction, and the porosity is significantly reduced in the shear zone and the grain size is smaller in the shear zone than in the host rock but there is no evidence for broken grains. Comparison of microstructures

  16. Cooperative deformations of periodically patterned hydrogels.

    PubMed

    Wang, Zhi Jian; Zhu, Chao Nan; Hong, Wei; Wu, Zi Liang; Zheng, Qiang

    2017-09-01

    Nature has shown elegant paradigms of smart deformation, which inspired biomimetic systems with controllable bending, folding, and twisting that are significant for the development of soft electronics and actuators. Complex deformations are usually realized by additively incorporating typical structures in selective domains with little interaction. We demonstrate the cooperative deformations of periodically patterned hydrogel sheets, in which neighboring domains mutually interact and cooperatively deform. Nonswelling disc gels are periodically positioned in a high-swelling gel. During the swelling process, the compartmentalized high-swelling gel alternately bends upward or downward to relieve the in-plane compression, but the overall integrated structure remains flat. The synergy between the elastic mismatch and the geometric periodicity selects the outcome pattern. Both experiment and modeling show that various types of cooperative deformation can be achieved by tuning the pattern geometry and gel properties. Different responsive polymers can also be patterned in one composite gel. Under stimulation, reversible transformations between different cooperative deformations are realized. The principle of cooperative deformation should be applicable to other materials, and the patterns can be miniaturized to the micrometer- or nanometer-scale level, providing the morphing materials with advanced functionalities for applications in various fields.

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

    PubMed

    Scattergood, T W

    1987-01-01

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

  18. Deformation mechanisms and resealing of damage zones in experimentally deformed cemented and un-cemented clay-rich geomaterials, at low bulk strain

    NASA Astrophysics Data System (ADS)

    Desbois, Guillaume; Urai, Janos L.; Schuck, Bernhardt; Hoehne, Nadine; Oelker, Anne; Bésuelle, Pierre; Viggiani, Gioacchino; Schmatz, Joyce; Klaver, Jop

    2017-04-01

    A microphysics-based understanding of mechanical and fluid flow properties in clay-rich geomaterials is required for extrapolating better constitutive equations beyond the laboratory's time scales, so that predictions over the long term can be made less uncertain. In this contribution, we present microstructural investigations of rocks specimens sheared in triaxial compression at low bulk strain, by using the combination of broad-ion-beam (BIB) milling and scanning electron microscopy (SEM) to infer deformation mechanisms based on microstructures imaged at sub-micron resolution. Two end-member clay-rich geomaterials from European Underground Laboratories (URL) were analysed: (i) the poorly cemented Boom Clay sediment (BC from URL at Mol/Dessel, Belgium; confining pressure [CP] = 0.375 & 1.5 MPa) and (ii) the Callovo-Oxfordian claystone (COx from the URL at Bure, France; CP = 2 & 10 MPa). Although as a first approximation the inelastic bahvior of cemented and uncemented clay-rich geomaterials can be described by similar pressure-dependent hardening plasticity models, deformed samples in this contribution show very contrasting micro-scale behaviour: microstructures reveal brittle-ductile transitional behaviour in BC, whereas deformation in COx is dominantly cataclastic. In Boom Clay, at meso-scale, shear bands exhibit characteristics that are typical of uncemented small-grained clay-rich materials deformed at high shear strains, consisting of anastomosing shears interpreted as Y- and B-shears, which bound the passively deformed microlithons. At micro- down to nano-scale, the strong shape preferential orientation of clay aggregates in the anastomosing shears is interpreted to be responsible of the shear weakness. More over, the reworking of clay aggregates during deformation contributes to the collapsing of porosity in the shear band. Ductile deformation mechanisms represented by grain-rotation, grain-sliding, bending and granular flow mechanisms are strongly involved

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

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Suzuki-Vidal, F.; Lebedev, S. V.; Pickworth, L. A.

    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 scalesmore » 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.« less

  1. 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…

  2. Contemporaneous ring fault activity and surface deformation at subsiding calderas studied using analogue experiments

    NASA Astrophysics Data System (ADS)

    Liu, Yuan-Kai; Ruch, Joël; Vasyura-Bathke, Hannes; Jónsson, Sigurjón

    2017-04-01

    Ground deformation analyses of several subsiding calderas have shown complex and overlapping deformation signals, with a broad deflation signal that affects the entire volcanic edifice and localized subsidence focused within the caldera. However, the relation between deep processes at subsiding calderas, including magmatic sources and faulting, and the observed surface deformation is still debated. Several recent examples of subsiding calderas in the Galápagos archipelago and at the Axial seamount in the Pacific Ocean indicate that ring fault activity plays an important role not only during caldera collapse, but also during initial stages of caldera subsidence. Nevertheless, ring fault activity has rarely been integrated into numerical models of subsiding calderas. Here we report on sandbox analogue experiments that we use to study the processes involved from an initial subsidence to a later collapse of calderas. The apparatus is composed of a subsiding half piston section connected to the bottom of a glass box and driven by a motor to control its subsidence. We analyze at the same time during the subsidence the 3D displacement at the model surface with a laser scanner and the 2D ring fault evolution on the side of the model (cross-section) with a side-view digital camera. We further use PIVLab, a time-resolved digital image correlation software tool, to extract strain and velocity fields at both the surface and in cross-section. This setup allows to track processes acting at depth and assess their relative importance as the collapse evolves. We further compare our results with the examples observed in nature as well as with numerical models that integrate ring faults.

  3. Study on Elastic Helical TDR Sensing Cable for Distributed Deformation Detection

    PubMed Central

    Tong, Renyuan; Li, Ming; Li, Qing

    2012-01-01

    In order to detect distributed ground surface deformation, an elastic helical structure Time Domain Reflectometry (TDR) sensing cable is shown in this paper. This special sensing cable consists of three parts: a silicone rubber rope in the center; a couple of parallel wires coiling around the rope; a silicone rubber pipe covering the sensing cable. By analyzing the relationship between the impedance and the structure of the sensing cable, the impedance model shows that the sensing cable impedance will increase when the cable is stretched. This specific characteristic is verified in the cable stretching experiment which is the base of TDR sensing technology. The TDR experiment shows that a positive reflected signal is created at the stretching deformation point on the sensing cable. The results show that the deformation section length and the stretching elongation will both affect the amplitude of the reflected signal. Finally, the deformation locating experiments show that the sensing cable can accurately detect the deformation point position on the sensing cable. PMID:23012560

  4. 40Ar* loss in experimentally deformed muscovite and biotite with implications for 40Ar/39Ar geochronology of naturally deformed rocks

    USGS Publications Warehouse

    Cosca, Michael; Stunitz, Holger; Bourgiex, Anne-Lise; Lee, John P.

    2011-01-01

    The effects of deformation on radiogenic argon (40Ar*) retentivity in mica are described from high pressure experiments performed on rock samples of peraluminous granite containing euhedral muscovite and biotite. Cylindrical cores, ~15 mm in length and 6.25 mm in diameter, were drilled from granite collected from the South Armorican Massif in northwestern France, loaded into gold capsules, and weld-sealed in the presence of excess water. The samples were deformed at a pressure of 10 kb and a temperature of 600 degrees C over a period 29 of hours within a solid medium assembly in a Griggs-type triaxial hydraulic deformation apparatus. Overall shortening in the experiments was approximately 10%. Transmitted light and secondary and backscattered electron imaging of the deformed granite samples reveals evidence of induced defects and for significant physical grain size reduction by kinking, cracking, and grain segmentation of the micas.

  5. Scaled laboratory experiments explain the kink behaviour of the Crab Nebula jet

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, C. K.; Tzeferacos, P.; Lamb, D.

    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 observed in jets associated with pulsar wind nebulae and other astrophysical objects, and therefore is a fundamental feature of astrophysical jet evolution that needs to be understood. Theoretical modeling and numerical simulations have suggested that this phenomenon may be a consequence of magnetic fields (B) and current-driven magnetohydrodynamic (MHD) instabilities taking place in the jet, but until now there has been no verification of this process in a controlled laboratory environment. Here we reportmore » the first such experiments, using scaled laboratory plasma jets generated by high-power lasers to model the Crab jet and monoenergetic-proton radiography to provide direct visualization and measurement of magnetic fields and their behavior. The toroidal magnetic field embedded in the supersonic jet triggered plasma instabilities and resulted in considerable deflections throughout the jet propagation, mimicking the kinks in the Crab jet. We also demonstrated that these kinks are stabilized by high jet velocity, consistent with the observation that instabilities alter the jet orientation but do not disrupt the overall jet structure. We successfully modeled these laboratory experiments with a validated three-dimensional (3D) numerical simulation, 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, kinked jet in the Crab nebula. The experiments initiate a novel approach in the laboratory for visualizing fields and instabilities associated with jets observed in various astrophysical objects, ranging from stellar to extragalactic systems. We expect that future work along this line will have important impact on the study and understanding of such fundamental

  6. Scaled laboratory experiments explain the kink behaviour of the Crab Nebula jet

    DOE PAGES

    Li, C. K.; Tzeferacos, P.; Lamb, D.; ...

    2016-10-07

    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 observed in jets associated with pulsar wind nebulae and other astrophysical objects, and therefore is a fundamental feature of astrophysical jet evolution that needs to be understood. Theoretical modeling and numerical simulations have suggested that this phenomenon may be a consequence of magnetic fields (B) and current-driven magnetohydrodynamic (MHD) instabilities taking place in the jet, but until now there has been no verification of this process in a controlled laboratory environment. Here we reportmore » the first such experiments, using scaled laboratory plasma jets generated by high-power lasers to model the Crab jet and monoenergetic-proton radiography to provide direct visualization and measurement of magnetic fields and their behavior. The toroidal magnetic field embedded in the supersonic jet triggered plasma instabilities and resulted in considerable deflections throughout the jet propagation, mimicking the kinks in the Crab jet. We also demonstrated that these kinks are stabilized by high jet velocity, consistent with the observation that instabilities alter the jet orientation but do not disrupt the overall jet structure. We successfully modeled these laboratory experiments with a validated three-dimensional (3D) numerical simulation, 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, kinked jet in the Crab nebula. The experiments initiate a novel approach in the laboratory for visualizing fields and instabilities associated with jets observed in various astrophysical objects, ranging from stellar to extragalactic systems. We expect that future work along this line will have important impact on the study and understanding of such fundamental

  7. Modeling rock specimens through 3D printing: Tentative experiments and prospects

    NASA Astrophysics Data System (ADS)

    Jiang, Quan; Feng, Xiating; Song, Lvbo; Gong, Yahua; Zheng, Hong; Cui, Jie

    2016-02-01

    Current developments in 3D printing (3DP) technology provide the opportunity to produce rock-like specimens and geotechnical models through additive manufacturing, that is, from a file viewed with a computer to a real object. This study investigated the serviceability of 3DP products as substitutes for rock specimens and rock-type materials in experimental analysis of deformation and failure in the laboratory. These experiments were performed on two types of materials as follows: (1) compressive experiments on printed sand-powder specimens in different shapes and structures, including intact cylinders, cylinders with small holes, and cuboids with pre-existing cracks, and (2) compressive and shearing experiments on printed polylactic acid cylinders and molded shearing blocks. These tentative tests for 3DP technology have exposed its advantages in producing complicated specimens with special external forms and internal structures, the mechanical similarity of its product to rock-type material in terms of deformation and failure, and its precision in mapping shapes from the original body to the trial sample (such as a natural rock joint). These experiments and analyses also successfully demonstrate the potential and prospects of 3DP technology to assist in the deformation and failure analysis of rock-type materials, as well as in the simulation of similar material modeling experiments.

  8. Time-dependent deformation at elevated temperatures in basalt from El Hierro, Stromboli and Teide volcanoes

    NASA Astrophysics Data System (ADS)

    Benson, P. M.; Fahrner, D.; Harnett, C. E.; Fazio, M.

    2014-12-01

    Time dependent deformation describes the process whereby brittle materials deform at a stress level below their short-term material strength (Ss), but over an extended time frame. Although generally well understood in engineering (where it is known as static fatigue or "creep"), knowledge of how rocks creep and fail has wide ramifications in areas as diverse as mine tunnel supports and the long term stability of critically loaded rock slopes. A particular hazard relates to the instability of volcano flanks. A large number of flank collapses are known such as Stromboli (Aeolian islands), Teide, and El Hierro (Canary Islands). Collapses on volcanic islands are especially complex as they necessarily involve the combination of active tectonics, heat, and fluids. Not only does the volcanic system generate stresses that reach close to the failure strength of the rocks involved, but when combined with active pore fluid the process of stress corrosion allows the rock mass to deform and creep at stresses far lower than Ss. Despite the obvious geological hazard that edifice failure poses, the phenomenon of creep in volcanic rocks at elevated temperatures has yet to be thoroughly investigated in a well controlled laboratory setting. We present new data using rocks taken from Stromboli, El Heirro and Teide volcanoes in order to better understand the interplay between the fundamental rock mechanics of these basalts and the effects of elevated temperature fluids (activating stress corrosion mechanisms). Experiments were conducted over short (30-60 minute) and long (8-10 hour) time scales. For this, we use the method of Heap et al., (2011) to impose a constant stress (creep) domain deformation monitored via non-contact axial displacement transducers. This is achieved via a conventional triaxial cell to impose shallow conditions of pressure (<25 MPa) and temperature (<200 °C), and equipped with a 3D laboratory seismicity array (known as acoustic emission, AE) to monitor the micro

  9. Eight year experience in open ended instrumentation laboratory

    NASA Astrophysics Data System (ADS)

    Marques, Manuel B.; Rosa, Carla C.; Marques, Paulo V. S.

    2015-10-01

    When designing laboratory courses in a Physics Major we consider a range of objectives: teaching Physics; developing lab competencies; instrument control and data acquisition; learning about measurement errors and error propagation; an introduction to project management; team work skills and scientific writing. But nowadays we face pressure to decrease laboratory hours due to the cost involved. Many universities are replacing lab classes for simulation activities, hiring PhD. and master students to give first year lab classes, and reducing lab hours. This leads to formatted lab scripts and poor autonomy of the students, and failure to enhance creativity and autonomy. In this paper we present our eight year experience with a laboratory course that is mandatory in the third year of Physics and Physical Engineering degrees. Since the students had previously two standard laboratory courses, we focused on teaching instrumentation and giving students autonomy. The course is divided in two parts: one third is dedicated to learn computer controlled instrumentation and data acquisition (based in LabView); the final 2/3 is dedicated to a group project. In this project, the team (2 or 3 students) must develop a project and present it in a typical conference format at the end of the semester. The project assignments are usually not very detailed (about two or three lines long), giving only general guidelines pointing to a successful project (students often recycle objectives putting forward a very personal project); all of them require assembling some hardware. Due to our background, about one third of the projects are related to Optics.

  10. Microfluidic assay of the deformability of primitive erythroblasts.

    PubMed

    Zhou, Sitong; Huang, Yu-Shan; Kingsley, Paul D; Cyr, Kathryn H; Palis, James; Wan, Jiandi

    2017-09-01

    Primitive erythroblasts (precursors of red blood cells) enter vascular circulation during the embryonic period and mature while circulating. As a result, primitive erythroblasts constantly experience significant hemodynamic shear stress. Shear-induced deformation of primitive erythroblasts however, is poorly studied. In this work, we examined the deformability of primitive erythroblasts at physiologically relevant flow conditions in microfluidic channels and identified the regulatory roles of the maturation stage of primitive erythroblasts and cytoskeletal protein 4.1 R in shear-induced cell deformation. The results showed that the maturation stage affected the deformability of primitive erythroblasts significantly and that primitive erythroblasts at later maturational stages exhibited a better deformability due to a matured cytoskeletal structure in the cell membrane.

  11. Soft-bed experiments beneath Engabreen, Norway: Regelation, infiltration, basal slip and bed deformation

    USGS Publications Warehouse

    Iverson, N.R.; Hooyer, T.S.; Fischer, U.H.; Cohen, D.; Moore, P.L.; Jackson, M.; Lappegard, G.; Kohler, J.

    2007-01-01

    To avoid some of the limitations of studying soft-bed processes through boreholes, a prism of simulated till (1.8 m ?? 1.6 m ?? 0.45 m) with extensive instrumentation was constructed in a trough blasted in the rock bed of Engabreen, a temperate glacier in Norway. Tunnels there provide access to the bed beneath 213 m of ice. Pore-water pressure was regulated in the prism by pumping water to it. During experiments lasting 7-12 days, the glacier regelated downward into the prism to depths of 50-80 mm, accreting ice-infiltrated till at rates predicted by theory. During periods of sustained high pore-water pressure (70-100% of overburden), ice commonly slipped over the prism, due to a water layer at the prism surface. Deformation of the prism was activated when this layer thinned to a sub-millimeter thickness. Shear strain in the till was pervasive and decreased with depth. A model of slip by ploughing of ice-infiltrated till across the prism surface accounts for the slip that occurred when effective pressure was sufficiently low or high. Slip at low effective pressures resulted from water-layer thickening that increased non-linearly with decreasing effective pressure. If sufficiently widespread, such slip over soft glacier beds, which involves no viscous deformation resistance, may instigate abrupt increases in glacier velocity.

  12. 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

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

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  14. Deformed Palmprint Matching Based on Stable Regions.

    PubMed

    Wu, Xiangqian; Zhao, Qiushi

    2015-12-01

    Palmprint recognition (PR) is an effective technology for personal recognition. A main problem, which deteriorates the performance of PR, is the deformations of palmprint images. This problem becomes more severe on contactless occasions, in which images are acquired without any guiding mechanisms, and hence critically limits the applications of PR. To solve the deformation problems, in this paper, a model for non-linearly deformed palmprint matching is derived by approximating non-linear deformed palmprint images with piecewise-linear deformed stable regions. Based on this model, a novel approach for deformed palmprint matching, named key point-based block growing (KPBG), is proposed. In KPBG, an iterative M-estimator sample consensus algorithm based on scale invariant feature transform features is devised to compute piecewise-linear transformations to approximate the non-linear deformations of palmprints, and then, the stable regions complying with the linear transformations are decided using a block growing algorithm. Palmprint feature extraction and matching are performed over these stable regions to compute matching scores for decision. Experiments on several public palmprint databases show that the proposed models and the KPBG approach can effectively solve the deformation problem in palmprint verification and outperform the state-of-the-art methods.

  15. Fluid-Driven Deformation of a Soft Porous Medium

    NASA Astrophysics Data System (ADS)

    Lutz, Tyler; Wilen, Larry; Wettlaufer, John

    2017-11-01

    Viscous drag forces resisting the flow of fluid through a soft porous medium are maintained by restoring forces associated with deformations in the solid matrix. We describe experimental measurements of the deformation of foam under a pressure-driven flow of water along a single axis. Image analysis techniques allow tracking of the foam displacement while pressure sensors allow measurement of the fluid pressure. Experiments are performed for a series of different pressure heads ranging from 10 to 90 psi, and the results are compared to theory. This work builds on previous measurements of the fluid-induced deformation of a bed of soft hydrogel spheres. Compared to the hydrogel system, foams have the advantage that the constituents of the porous medium do not rearrange during an experiment, but they have the disadvantage of having a high friction coefficient with any boundaries. We detail strategies to characterize and mitigate the effects of friction on the observed foam deformations.

  16. An Undergraduate Biochemistry Laboratory Course with an Emphasis on a Research Experience

    ERIC Educational Resources Information Center

    Caspers, Mary Lou; Roberts-Kirchhoff, Elizabeth S.

    2003-01-01

    In their junior or senior year, biochemistry majors at the University of Detroit Mercy are required to take a two-credit biochemistry laboratory course. Five years ago, the format of this course was changed from structured experiments to a more project-based approach. Several structured experiments were included at the beginning of the course…

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

    ERIC Educational Resources Information Center

    Turchi, Sandra L.; Weiss, Monica

    1988-01-01

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

  18. 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.…

  19. 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.

  20. 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.

  1. Analytical and Experimental Verification of a Flight Article for a Mach-8 Boundary-Layer Experiment

    NASA Technical Reports Server (NTRS)

    Richards, W. Lance; Monaghan, Richard C.

    1996-01-01

    Preparations for a boundary-layer transition experiment to be conducted on a future flight mission of the air-launched Pegasus(TM) rocket are underway. The experiment requires a flight-test article called a glove to be attached to the wing of the Mach-8 first-stage booster. A three-dimensional, nonlinear finite-element analysis has been performed and significant small-scale laboratory testing has been accomplished to ensure the glove design integrity and quality of the experiment. Reliance on both the analysis and experiment activities has been instrumental in the success of the flight-article design. Results obtained from the structural analysis and laboratory testing show that all glove components are well within the allowable thermal stress and deformation requirements to satisfy the experiment objectives.

  2. Acoustic Emission Detected by Matched Filter Technique in Laboratory Earthquake Experiment

    NASA Astrophysics Data System (ADS)

    Wang, B.; Hou, J.; Xie, F.; Ren, Y.

    2017-12-01

    Acoustic Emission in laboratory earthquake experiment is a fundamental measures to study the mechanics of the earthquake for instance to characterize the aseismic, nucleation, as well as post seismic phase or in stick slip experiment. Compared to field earthquake, AEs are generally recorded when they are beyond threshold, so some weak signals may be missing. Here we conducted an experiment on a 1.1m×1.1m granite with a 1.5m fault and 13 receivers with the same sample rate of 3MHz are placed on the surface. We adopt continues record and a matched filter technique to detect low-SNR signals. We found there are too many signals around the stick-slip and the P- arrival picked by manual may be time-consuming. So, we combined the short-term average to long-tem-average ratio (STA/LTA) technique with Autoregressive-Akaike information criterion (AR-AIC) technique to pick the arrival automatically and found mostly of the P- arrival accuracy can satisfy our demand to locate signals. Furthermore, we will locate the signals and apply a matched filter technique to detect low-SNR signals. Then, we can see if there is something interesting in laboratory earthquake experiment. Detailed and updated results will be present in the meeting.

  3. 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

  4. Simultaneous concentration and purification through gradient deformation chromatography

    NASA Technical Reports Server (NTRS)

    Velayudhan, A.; Hendrickson, R. L.; Ladisch, M. R.; Mitchell, C. A. (Principal Investigator)

    1995-01-01

    Mobile-phase additives, commonly used to modulate absorbate retention in gradient elution chromatography, are usually assumed to be either linearly retained or unretained. Previous theoretical work from our laboratory has shown that these modulators, such as salts in ion-exchange and hydrophobic interaction chromatography and organic modifiers in reversed-phase chromatography, can absorb nonlinearly, giving rise to gradient deformation. Consequently, adsorbate peaks that elute in the vicinity of the head of the deformed gradient may exhibit unusual shapes, form shoulders, and/or be concentrated. These effects for a reversed-phase sorbent with aqueous acetonitrile (ACN) as the modulator are verified experimentally. Gradient deformation is demonstrated experimentally and agrees with simulations based on ACN isotherm parameters that are independently determined from batch equilibrium studies using the layer model. Unusual absorbate peak shapes were found experimentally for single-component injections of phenylalanine, similar to those calculated by the simulations. A binary mixture of tryptophan and phenylalanine is used to demonstrate simultaneous concentration and separation, again in agreement with simulations. The possibility of gradient deformation in ion-exchange and hydrophobic interaction chromatography is discussed.

  5. Geodetic Measurements and Mechanical Models of Cyclic Deformation at Okmok Volcano, Alaska

    NASA Astrophysics Data System (ADS)

    Feigl, K.; Masterlark, T.; Lu, Z.; Ohlendorf, S. J.; Thurber, C. H.; Sigmundsson, F.

    2009-12-01

    The 1997 and 2008 eruptions of Okmok volcano, Alaska, provide a rare opportunity for conducting a rheological experiment to unravel the complex processes associated with magma migration, storage, and eruption in an active volcano. In this experiment, the magma flux during the eruption provides the “impulse” and the subsequent, transient deformation, the “response”. By simulating the impulse, measuring the response, and interpreting the constitutive relations between the two, one can infer the rheology. Okmok is an excellent natural laboratory for such an experiment because a complete cycle of deformation has been monitored using geodetic and seismic means, including: (a) geodetic time series from Interferometric Synthetic Aperture Radar (InSAR) and the Global Positioning System (GPS), (b) earthquake locations; and (c) seismic tomography. We are developing quantitative models using the Finite Element Method (FEM) to simulate the timing and location of the observed seismicity and deformation by accounting for: (a) the geometry and loading of the magma chamber and lava flow, (b) the spatial distribution of material properties; and (c) the constitutive (rheological) relations between stress and strain. Here, we test the hypothesis that the deformation following the 1997 eruption did not reach a steady state before the eruption in 2008. To do so, we iteratively confront the FEM models with the InSAR measurements using the General Inversion of Phase Technique (GIPhT). This approach models the InSAR phase data directly, without unwrapping, as developed, validated, and applied by Feigl and Thurber [Geophys. J. Int., 2009]. By minimizing a cost function that quantifies the misfit between observed and modeled values in terms of “wrapped” phase (with values ranging from -1/2 to +1/2 cycles), GIPhT can estimate parameters in a geophysical model. By avoiding the pitfalls of phase-unwrapping approaches, GIPhT allows the analysis, interpretation and modeling of more

  6. An Advanced Undergraduate Chemistry Laboratory Experiment Exploring NIR Spectroscopy and Chemometrics

    ERIC Educational Resources Information Center

    Wanke, Randall; Stauffer, Jennifer

    2007-01-01

    An advanced undergraduate chemistry laboratory experiment to study the advantages and hazards of the coupling of NIR spectroscopy and chemometrics is described. The combination is commonly used for analysis and process control of various ingredients used in agriculture, petroleum and food products.

  7. Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms

    ERIC Educational Resources Information Center

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

    2014-01-01

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

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

    ERIC Educational Resources Information Center

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

    1979-01-01

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

  9. Fluid Surface Deformation by Objects in the Cheerios Effect

    NASA Astrophysics Data System (ADS)

    Nguyen, Khoi; Miller, Michael; Mandre, Shreyas; Mandre Lab Team

    2012-11-01

    Small objects floating on a fluid/air interface deform of the surface depending on material surface properties, density, and geometry. These objects attract each other through capillary interactions, a phenomenon dubbed the ``cheerios effect.'' The attractive force and torque exerted on these objects by the interface can be estimated if the meniscus deformation is known. In addition, the floating objects can also rotate due to such an interaction. We present a series of experiments focused on visualizing the the motions of the floating objects and the deformation of the interface. The experiments involve thin laser-cut acrylic pieces attracting each other on water in a large glass petri dish and a camera set-up to capture the process. Furthermore, optical distortion of a grid pattern is used to visualize the water surface deformation near the edge of the objects. This study of the deformation of the water surface around a floating object, of the attractive/repulsive forces, and of post-contact rotational dynamics are potentially instrumental in the study of colloidal self-assembly.

  10. A furnace with rotating load frame for in situ high temperature deformation and creep experiments in a neutron diffraction beam line

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Reiche, H. M.; New Mexico State University, Las Cruces, New Mexico 88003; Vogel, S. C.

    2012-05-15

    A resistive furnace combined with a load frame was built that allows for in situ neutron diffraction studies of high temperature deformation, in particular, creep. A maximum force of 2700 N can be applied at temperatures up to 1000 deg. C. A load control mode permits studies of, e.g., creep or phase transformations under applied uni-axial stress. In position control, a range of high temperature deformation experiments can be achieved. The examined specimen can be rotated up to 80 deg. around the vertical compression axis allowing texture measurements in the neutron time-of-flight diffractometer HIPPO (High Pressure - Preferred Orientation). Wemore » present results from the successful commissioning, deforming a Zr-2.5 wt.% Nb cylinder at 975 deg. C. The device is now available for the user program of the HIPPO diffractometer at the LANSCE (Los Alamos Neutron Science Center) user facility.« less

  11. 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…

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

    USGS Publications Warehouse

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

    1993-01-01

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

  13. Measuring skewness of red blood cell deformability distribution by laser ektacytometry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nikitin, S Yu; Priezzhev, A V; Lugovtsov, A E

    An algorithm is proposed for measuring the parameters of red blood cell deformability distribution based on laser diffractometry of red blood cells in shear flow (ektacytometry). The algorithm is tested on specially prepared samples of rat blood. In these experiments we succeeded in measuring the mean deformability, deformability variance and skewness of red blood cell deformability distribution with errors of 10%, 15% and 35%, respectively. (laser biophotonics)

  14. Fluid flow simulation and permeability computation in deformed porous carbonate grainstones

    NASA Astrophysics Data System (ADS)

    Zambrano, Miller; Tondi, Emanuele; Mancini, Lucia; Lanzafame, Gabriele; Trias, F. Xavier; Arzilli, Fabio; Materazzi, Marco; Torrieri, Stefano

    2018-05-01

    In deformed porous carbonates, the architecture of the pore network may be modified by deformation or diagenetic processes altering the permeability with respect to the pristine rock. The effects of the pore texture and morphology on permeability in porous rocks have been widely investigated due to the importance during the evaluation of geofluid reservoirs. In this study, these effects are assessed by combining synchrotron X-ray computed microtomography (SR micro-CT) and computational fluid dynamics. The studied samples pertain to deformed porous carbonate grainstones highly affected by deformation bands (DBs) exposed in Northwestern Sicily and Abruzzo regions, Italy. The high-resolution SR micro-CT images of the samples, acquired at the SYRMEP beamline of the Elettra - Sincrotrone Trieste laboratory (Italy), were used for simulating a pressure-driven flow by using the lattice-Boltzmann method (LBM). For the experiments, a multiple relaxation time (MRT) model with the D3Q19 scheme was used to avoid viscosity-dependent results of permeability. The permeability was calculated using Darcy's law once steady conditions were reached. After the simulations, the pore-network properties (effective porosity, specific surface area, and geometrical tortuosity) were calculated using 3D images of the velocity fields. These images were segmented considering a velocity threshold value higher than zero. The study showed that DBs may generate significant heterogeneity and anisotropy of the permeability of the evaluated rock samples. Cataclasis and cementation process taking place within the DBs reduce the effective porosity and therefore the permeability. Contrary to this, pressure dissolution and faulting may generate connected channels which contribute to the permeability only parallel to the DB.

  15. Investigating Affective Experiences in the Undergraduate Chemistry Laboratory: Students' Perceptions of Control and Responsibility

    ERIC Educational Resources Information Center

    Galloway, Kelli R.; Malakpa, Zoebedeh; Bretz, Stacey Lowery

    2016-01-01

    Meaningful learning requires the integration of cognitive and affective learning with the psychomotor, i.e., hands-on learning. The undergraduate chemistry laboratory is an ideal place for meaningful learning to occur. However, accurately characterizing students' affective experiences in the chemistry laboratory can be a very difficult task. While…

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

    ERIC Educational Resources Information Center

    Tsionsky, Vladimir

    2007-01-01

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

  17. Plate-rate laboratory friction experiments reveal potential slip instability on weak faults

    NASA Astrophysics Data System (ADS)

    Ikari, M.; Kopf, A.

    2016-12-01

    In earthquake science, it is commonly assumed that earthquakes nucleate on strong patches or "asperities", and data from laboratory friction experiments indicate a tendency for unstable slip (exhibited as velocity-weakening frictional behavior) in strong geologic materials. However, an overwhelming amount of these experiments were conducted at driving velocities ranging from 0.1 µm/s to over 1 m/s. Less data exists for shearing experiments driven at slow velocities on the order of cm/yr (nm/s), approximating plate tectonic rates which represent the natural driving condition on plate boundary faults. Recent laboratory work using samples recovered from the Tohoku region at the Japan Trench, within the high coseismic slip region of the 2011 M9 Tohoku earthquake, showed that the fault is extremely weak with a friction coefficient < 0.2. At sliding velocities of at least 0.1 µm/s mostly velocity-strengthening friction is observed, which is favorable for stable creep, consistent with earlier work. However, shearing at an imposed rate of 8.5 cm/yr produced both velocity-weakening friction and discrete slow slip events, which are likely instances of frictional instabilities or quasi-instabilities. Here, we expand on the Tohoku experiment by conducting cm/yr friction experiments on natural gouges obtained from a variety of other major fault zones obtained by scientific drilling; these include the San Andreas Fault, Costa Rica subduction zone, Nankai Trough (Japan), Barbados subduction zone, Alpine Fault (New Zealand), southern Cascadia, and Woodlark Basin (Papua New Guinea). We focus here on weak fault materials having a friction coefficient of < 0.5. At conventional laboratory driving rates of 0.1-30 µm/s, velocity strengthening is common. However, at cm/yr driving rates we commonly observe velocity-weakening friction and slow slip events, with most samples exhibit both behaviors. These results demonstrate when fault samples are sheared at plate tectonic rates in the

  18. Interfacial diffusion aided deformation during nanoindentation

    DOE PAGES

    Samanta, Amit; E., Weinan

    2015-07-06

    Nanoindentation is commonly used to quantify the mechanical response of material surfaces. Despite its widespread use, a detailed understanding of the deformation mechanisms responsible for plasticity during these experiments has remained elusive. Nanoindentation measurements often show stress values close to a material’s ideal strength which suggests that dislocation nucleation and subsequent dislocation activity dominates the deformation. However, low strain-rate exponents and small activation volumes have also been reported which indicates high temperature sensitivity of the deformation processes. Using an order parameter aided temperature accelerated sampling technique called adiabatic free energy dynamics [J. B. Abrams and M. E. Tuckerman, J. Phys.more » Chem. B, 112, 15742 (2008)], and molecular dynamics we have probed the diffusive mode of deformation during nanoindentation. Localized processes such as surface vacancy and ad-atom pair formation, vacancy diffusion are found to play an important role during indentation. Furthermore, our analysis suggests a change in the dominant deformation mode from dislocation mediated plasticity to diffusional flow at high temperatures, slow indentation rates and small indenter tip radii.« less

  19. Discovering Inexpensive, Effective Catalysts for Solar Energy Conversion: An Authentic Research Laboratory Experience

    ERIC Educational Resources Information Center

    Shaner, Sarah E.; Hooker, Paul D.; Nickel, Anne-Marie; Leichtfuss, Amanda R.; Adams, Carissa S.; de la Cerda, Dionisia; She, Yuqi; Gerken, James B.; Pokhrel, Ravi; Ambrose, Nicholas J.; Khaliqi, David; Stahl, Shannon S.; Schuttlefield Christus, Jennifer D.

    2016-01-01

    Electrochemical water oxidation is a major focus of solar energy conversion efforts. A new laboratory experiment has been developed that utilizes real-time, hands-on research to discover catalysts for solar energy conversion. The HARPOON, or Heterogeneous Anodes Rapidly Perused for Oxygen Overpotential Neutralization, experiment allows an array of…

  20. Perceptual transparency from image deformation.

    PubMed

    Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin'ya

    2015-08-18

    Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid's surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of "invisible" transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation.

  1. Control code for laboratory adaptive optics teaching system

    NASA Astrophysics Data System (ADS)

    Jin, Moonseob; Luder, Ryan; Sanchez, Lucas; Hart, Michael

    2017-09-01

    By sensing and compensating wavefront aberration, adaptive optics (AO) systems have proven themselves crucial in large astronomical telescopes, retinal imaging, and holographic coherent imaging. Commercial AO systems for laboratory use are now available in the market. One such is the ThorLabs AO kit built around a Boston Micromachines deformable mirror. However, there are limitations in applying these systems to research and pedagogical projects since the software is written with limited flexibility. In this paper, we describe a MATLAB-based software suite to interface with the ThorLabs AO kit by using the MATLAB Engine API and Visual Studio. The software is designed to offer complete access to the wavefront sensor data, through the various levels of processing, to the command signals to the deformable mirror and fast steering mirror. In this way, through a MATLAB GUI, an operator can experiment with every aspect of the AO system's functioning. This is particularly valuable for tests of new control algorithms as well as to support student engagement in an academic environment. We plan to make the code freely available to the community.

  2. Comparative Laboratory and Numerical Simulations of Shearing Granular Fault Gouge: Micromechanical Processes

    NASA Astrophysics Data System (ADS)

    Morgan, J. K.; Marone, C. J.; Guo, Y.; Anthony, J. L.; Knuth, M. W.

    2004-12-01

    Laboratory studies of granular shear zones have provided significant insight into fault zone processes and the mechanics of earthquakes. The micromechanisms of granular deformation are more difficult to ascertain, but have been hypothesized based on known variations in boundary conditions, particle properties and geometries, and mechanical behavior. Numerical simulations using particle dynamics methods (PDM) can offer unique views into deforming granular shear zones, revealing the precise details of granular microstructures, particle interactions, and packings, which can be correlated with macroscopic mechanical behavior. Here, we describe a collaborative program of comparative laboratory and numerical experiments of granular shear using idealized materials, i.e., glass beads, glass rods or pasta, and angular sand. Both sets of experiments are carried out under similar initial and boundary conditions in a non-fracturing stress regime. Phenomenologically, the results of the two sets of experiments are very similar. Peak friction values vary as a function of particle dimensionality (1-D vs. 2-D vs. 3-D), particle angularity, particle size and size distributions, boundary roughness, and shear zone thickness. Fluctuations in shear strength during an experiment, i.e., stick-slip events, can be correlated with distinct changes in the nature, geometries, and durability of grain bridges that support the shear zone walls. Inclined grain bridges are observed to form, and to support increasing loads, during gradual increases in assemblage strength. Collapse of an individual grain bridge leads to distinct localization of strain, generating a rapidly propagating shear surface that cuts across multiple grain bridges, accounting for the sudden drop in strength. The distribution of particle sizes within an assemblage, along with boundary roughness and its periodicity, influence the rate of formation and dissipation of grain bridges, thereby controlling friction variations during

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

    ERIC Educational Resources Information Center

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

    2009-01-01

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

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

    ERIC Educational Resources Information Center

    Marcolongo, Juan P.; Mirenda, Martin

    2011-01-01

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

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  6. Cognitive Responses to Mass Communication: Results from Laboratory Studies and a Field Experiment.

    ERIC Educational Resources Information Center

    Ward, Scott; Ray, Michael L.

    This paper examines some of the cognitive responses people experience while attending to messages. Two laboratory studies and a field experiment were conducted. In the lab studies, three different audience groups (junior and senior high school students and parents) were shown three different anti-drug abuse messages. Various levels of audio…

  7. Exploring deformation scenarios in Timanfaya volcanic area (Lanzarote, Canary Islands) from GNSS and ground based geodetic observations

    NASA Astrophysics Data System (ADS)

    Riccardi, U.; Arnoso, J.; Benavent, M.; Vélez, E.; Tammaro, U.; Montesinos, F. G.

    2018-05-01

    We report on a detailed geodetic continuous monitoring in Timanfaya volcanic area (TVA), where the most intense geothermal anomalies of Lanzarote Island are located. We analyze about three years of GNSS data collected on a small network of five permanent stations, one of which at TVA, deployed on the island, and nearly 20 years of tiltmeter and strainmeter records acquired at Los Camelleros site settled in the facilities of the Geodynamics Laboratory of Lanzarote within TVA. This study is intended to contribute to understanding the active tectonics on Lanzarote Island and its origin, mainly in TVA. After characterizing and filtering out the seasonal periodicities related to "non-tectonic" sources from the geodetic records, a tentative ground deformation field is reconstructed through the analysis of both tilt, strain records and the time evolution of the baselines ranging the GNSS stations. The joint interpretation of the collected geodetic data show that the area of the strongest geothermal anomaly in TVA is currently undergoing a SE trending relative displacement at a rate of about 3 mm/year. This area even experiences a significant subsidence with a maximum rate of about 6 mm/year. Moreover, we examine the possible relation between the observed deformations and atmospheric effects by modelling the response functions of temperature and rain recorded in the laboratory. Finally, from the retrieval of the deformation patterns and the joint analysis of geodetic and environmental observations, we propose a qualitative model of the interplaying role between the hydrological systems and the geothermal anomalies. Namely, we explain the detected time correlation between rainfall and ground deformation because of the enhancement of the thermal transfer from the underground heat source driven by the infiltration of meteoric water.

  8. Preheat Measurements for Supernova Hydrodynamics Experiments

    NASA Astrophysics Data System (ADS)

    Krauland, Christine; Kuranz, Carolyn; Drake, Paul; Grosskopf, Mike; Campbell, Duncan

    2007-11-01

    The use of multi-kilojoule, ns lasers to launch shock waves has become a standard method for initiating hydrodynamic experiments in the field of Laboratory Astrophysics. However, the intense laser ablation that creates moving plasma also leads to the production of unwanted energetic x-rays and suprathermal electrons, both of which can be sources of material preheating. In principle, this preheat can alter the conditions of the experimental setup prior to the desired experiment actually taking place. At the University of Michigan, ongoing Rayleigh-Taylor instability experiments are defined by precise initial conditions, and potential deformation due to preheat could greatly affect their accuracy. An experiment devised and executed in an attempt to assess the preheat in this specific case will be presented, along with the quantitative analysis of the data obtained.

  9. Use of Digital Volume Correlation to Measure Deformation of Shale Using Natural Markers

    NASA Astrophysics Data System (ADS)

    Dewers, T. A.; Quintana, E.; Ingraham, M. D.; Jacques, C. L.

    2016-12-01

    We apply digital volume correlation (DVC) to interpreting deformation as influenced by shale heterogeneity. An extension of digital image correlation, DVC uses 3D images (CT Scans) of a sample before, during and after loading to determine deformation in terms of a 3D strain map. The technology tracks the deformation of high and low density regions within the sample to determine full field 3D strains within the sample. High pyrite shales (Woodford and Marcellus in this study) are being used as the high density pyrite serves as an excellent point to track in the volume correlation. Preliminary results indicate that this technology is promising for measuring true volume strains, strain localization, and strain portioning by microlithofacies within specimens during testing. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  10. Cross-disciplinary thermoregulation and sweat analysis laboratory experiences for undergraduate Chemistry and Exercise Science students.

    PubMed

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

    2011-06-01

    Cross-disciplinary (CD) learning experiences benefit student understanding of concepts and curriculum by offering opportunities to explore topics from the perspectives of alternate fields of study. This report involves a qualitative evaluation of CD health sciences undergraduate laboratory experiences in which concepts and students from two distinct disciplines [chemistry (CHEM) and exercise physiology (EPHE)] combined to study exercise thermoregulation and sweat analysis. Twenty-eight senior BSc Kinesiology (EPHE) students and 42 senior BSc CHEM students participated as part of their mutually exclusive, respective courses. The effectiveness of this laboratory environment was evaluated qualitatively using written comments collected from all students as well as from formal focus groups conducted after the CD laboratory with a representative cohort from each class (n = 16 CHEM students and 9 EPHE students). An open coding strategy was used to analyze the data from written feedback and focus group transcripts. Coding topics were generated and used to develop five themes found to be consistent for both groups of students. These themes reflected the common student perceptions that the CD experience was valuable and that students enjoyed being able to apply academic concepts to practical situations as well as the opportunity to interact with students from another discipline of study. However, students also reported some challenges throughout this experience that stemmed from the combination of laboratory groups from different disciplines with limited modification to the design of the original, pre-CD, learning environments. The results indicate that this laboratory created an effective learning opportunity that fostered student interest and enthusiasm for learning. The findings also provide information that could inform subsequent design and implementation of similar CD experiences to enhance engagement of all students and improve instructor efficacy.

  11. Clogging of an Alpine streambed by silt-sized particles - Insights from laboratory and field experiments.

    PubMed

    Fetzer, Jasmin; Holzner, Markus; Plötze, Michael; Furrer, Gerhard

    2017-12-01

    Clogging of streambeds by suspended particles (SP) can cause environmental problems, as it can negatively influence, e.g., habitats for macrozoobenthos, fish reproduction and groundwater recharge. This especially applies in the case of silt-sized SP. Until now, most research has dealt with coarse SP and was carried out in laboratory systems. The aims of this study are to examine (1) whether physical clogging by silt-sized SP exhibits the same dynamics and patterns as by sand-sized SP, and (2) the comparability of results between laboratory and field experiments. We carried out vertical column experiments with sand-sized bed material and silt-sized SP, which are rich in mica minerals. In laboratory experiments, we investigated the degree of clogging quantified by the reduction of porosity and hydraulic conductivity and the maximum clogging depth as a function of size and shape of bed material, size of SP, pore water flow velocity, and concentration of calcium cations. The SP were collected from an Alpine sedimentation basin, where our field experiments were carried out. To investigate the clogging process in the field, we buried columns filled with sand-sized quartz in the stream bed. We found that the maximal bed-to-grain ratio where clogging still occurs is larger for silt-sized SP than for sand-sized SP. The observed clogging depths and the reduction of flow rate through the column from our laboratory experiments were comparable to those from the field. However, our field results showed that the extent of clogging strongly depends on the naturally-occurring hydrological dynamics. The field location was characterized by a more polydisperse suspension, a strongly fluctuating water regime, and high SP concentrations at times, leading to more heterogeneous and more pronounced clogging when compared to laboratory results. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Gas Release as a Deformation Signal

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bauer, Stephen J.

    Radiogenic noble gases are contained in crustal rock at inter and intra granular sites. The gas composition depends on lithology, geologic history, fluid phases, and the aging effect by decay of U, Th, and K. The isotopic signature of noble gases found in rocks is vastly different than that of the atmosphere which is contributed by a variety of sources. When rock is subjected to stress conditions exceeding about half its yield strength, micro-cracks begin to form. As rock deformation progresses a fracture network evolves, releasing trapped noble gases and changing the transport properties to gas migration. Thus, changes inmore » gas emanation and noble gas composition from rocks could be used to infer changes in stress-state and deformation. The purpose of this study has been to evaluate the effect of deformation/strain rate upon noble gas release. Four triaxial experiments were attempted for a strain rate range of %7E10-8 /s (180,000s) to %7E 10-4/s (500s); the three fully successful experiments (at the faster strain rates) imply the following: (1) helium is measurably released for all strain rates during deformation, this release is in amounts 1-2 orders of magnitude greater than that present in the air, and (2) helium gas release increases with decreasing strain rate.« less

  13. Sensitivity studies and laboratory measurements for the laser heterodyne spectrometer experiment

    NASA Technical Reports Server (NTRS)

    Allario, F.; Katzberg, S. J.; Larsen, J. C.

    1980-01-01

    Several experiments involving spectral scanning interferometers and gas filter correlation radiometers (ref. 2) using limb scanning solar occultation techniques under development for measurements of stratospheric trace gases from Spacelab and satellite platforms are described. An experiment to measure stratospheric trace constituents by Laser Heterodyne Spectroscopy, a summary of sensitivity analyses, and supporting laboratory measurements are presented for O3, ClO, and H2O2 in which the instrument transfer function is modeled using a detailed optical receiver design.

  14. Droplet Deformation in an Extensional Flow: The Role of Surfactant Physical Chemistry

    NASA Technical Reports Server (NTRS)

    Stebe, Kathleen J.

    1996-01-01

    flow in a numerical and experimental program. Using surfactants whose dynamics and equilibrium behavior have been characterized in our laboratory, drop deformation will be studied in ground-based experiment. In an accompanying numerical study, predictive drop deformations will be determined based on the isotherm and equation of state determined in our laboratory. This work will improve our abilities to predict and control all fluid particle flows.

  15. Report on Microgravity Experiments of Dynamic Surface Deformation Effects on Marangoni Instability in High-Prandtl-Number Liquid Bridges

    NASA Astrophysics Data System (ADS)

    Yano, Taishi; Nishino, Koichi; Matsumoto, Satoshi; Ueno, Ichiro; Komiya, Atsuki; Kamotani, Yasuhiro; Imaishi, Nobuyuki

    2018-04-01

    This paper reports an overview and some important results of microgravity experiments called Dynamic Surf, which have been conducted on board the International Space Station from 2013 to 2016. The present project mainly focuses on the relations between the Marangoni instability in a high-Prandtl-number (Pr= 67 and 112) liquid bridge and the dynamic free surface deformation (DSD) as well as the interfacial heat transfer. The dynamic free surface deformations of large-scale liquid bridges (say, for diameters greater than 10 mm) are measured with good accuracy by an optical imaging technique. It is found that there are two causes of the dynamic free surface deformation in the present study: the first is the time-dependent flow behavior inside the liquid bridge due to the Marangoni instability, and the second is the external disturbance due to the residual acceleration of gravity, i.e., g-jitter. The axial distributions of DSD along the free surface are measured for several conditions. The critical parameters for the onset of oscillatory Marangoni convection are also measured for various aspect ratios (i.e., relative height to the diameter) of the liquid bridge and various thermal boundary conditions. The characteristics of DSD and the onset conditions of instability are discussed in this paper.

  16. Deformable and conformal silk hydrogel inverse opal

    PubMed Central

    Kim, Sookyoung; Kim, Sunghwan

    2017-01-01

    Photonic crystals (PhCs) efficiently manipulate photons at the nanoscale. Applying these crystals to biological tissue that has been subjected to large deformation and humid environments can lead to fascinating bioapplications such as in vivo biosensors and artificial ocular prostheses. These applications require that these PhCs have mechanical durability, deformability, and biocompatibility. Herein, we introduce a deformable and conformal silk hydrogel inverse opal (SHIO); the photonic lattice of this 3D PhC can be deformed by mechanical strain. This SHIO is prepared by the UV cross-linking of a liquid stilbene/silk solution, to give a transparent and elastic hydrogel. The pseudophotonic band gap (pseudo-PBG) of this material can be stably tuned by deformation of the photonic lattice (stretching, bending, and compressing). Proof-of-concept experiments demonstrate that the SHIO can be applied as an ocular prosthesis for better vision, such as that provided by the tapeta lucida of nocturnal or deep-sea animals. PMID:28559327

  17. Grain-scale investigations of deformation heterogeneities in aluminum alloys

    NASA Astrophysics Data System (ADS)

    Güler, Baran; Şimşek, Ülke; Yalçınkaya, Tuncay; Efe, Mert

    2018-05-01

    The anisotropic deformation of Aluminum alloys at micron scale exhibits localized deformation, which has negative implications on the macroscale mechanical and forming behavior. The scope of this work is twofold. Firstly, micro-scale deformation heterogeneities affecting forming behavior of aluminum alloys is investigated through experimental microstructure analysis at large strains and various strain paths. The effects of initial texture, local grain misorientation, and strain paths on the strain localizations are established. In addition to uniaxial tension condition, deformation heterogeneities are also investigated under equibiaxial tension condition to determine the strain path effects on the localization behavior. Secondly, the morphology and the crystallographic data obtained from the experiments is transferred to Abaqus software, in order to predict both macroscopic response and the microstructure evolution though crystal plasticity finite element simulations. The model parameters are identified through the comparison with experiments and the capability of the model to capture real material response is discussed as well.

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  19. Implementation of a laboratory quality assurance program: the Louisville experience.

    PubMed

    Metz, Michael J; Abdel-Azim, Tamer; Miller, Cynthia J; Lin, Wei-Shao; ZandiNejad, Amirali; Oliveira, Gustavo M; Morton, Dean

    2014-02-01

    Remakes, or the refabrication of dental prostheses, can occur as a result of inherent inaccuracies in both clinical and laboratory procedures. Because dental schools manage large numbers of predoctoral dental students with limited familiarity and expertise as related to clinical prosthodontic techniques, it is likely these schools will experience an elevated incidence of laboratory remakes and their ramifications. The University of Louisville School of Dentistry, not unlike other dental schools, has experienced remakes associated with both fixed and removable prosthodontic procedures. Limitations in faculty standardization and variable enforcement of established preclinical protocols have been identified as variables associated with the high percentage of remakes documented. The purpose of this study was to introduce the implementation of a new multidepartmental quality assurance program designed to increase consistency and quality in both information provided to commercial dental laboratories and the prostheses returned. The program has shown to be advantageous in terms of cost-effectiveness and treatment outcomes. A statistically significant decrease in remake percentages has been recorded from inception of this program in December 2010 until December 2012. Furthermore, this program has resulted in more consistent communication between the dental school and commercial dental laboratories, among faculty members, and between faculty and students.

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

    ERIC Educational Resources Information Center

    Sotheeswaran, Subramaniam

    1988-01-01

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

  1. Laboratory investigation of coupled deformation and fluid flow in mudrock: implications for slope stability in the Ursa Basin, Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Flemings, P. B.; Song, I.; Saffer, D. M.

    2012-04-01

    Integrated Ocean Drilling Program (IODP) Expedition 308 was dedicated to the study of fluid flow, overpressure, and slope stability in the Ursa Basin, on the continental slope of the Gulf of Mexico. In this location, turbidite channel levees deposited a wedge-shaped body: the deposition rate in the thick part of the wedge exceeded 12 mm/yr. This rapid deposition of fine grained sediments generated excess pore pressure observed near the seafloor. IODP drilling focused on three Sites: U1322, U1323, and U1324, along the steepest slope (2°) on the eastern section of the Ursa Canyon levee deposits. In this study, we conducted a suite of deformation experiments on samples from Site 1324, to understand the stress-strain behavior and stress history of the recovered core material. Our samples were taken from depths of 30-160 meters below seafloor, and are composed of ~40% silt and ~60% clay, with porosities ranging from ~42-55%. We first conducted uniaxial consolidation tests to determine pre-consolidation stresses and define deformation behavior due to simulated vertical loading. In a subset of tests, we subjected the samples to undrained shearing following consolidation, to define the friction angle and define relationships between stress state and deformation. We find that the lateral effective stress during uniaxial compression is 56-64% of the vertical effective stress (avg. K0=0.6). Pre-consolidation stresses suggest that pore pressure is hydrostatic to 50 mbsf (meters below seafloor), and is overpressured below this, with excess pressures up to 70% of the hydrostatic effective vertical stress (λ*=0.7) at 160 mbsf. The time coefficient of consolidation (cv) in these experiments is ~2.2x10-8 m2/s. Undrained shear tests define a failure envelope with a residual friction angle (φ) of 23° and zero cohesion. In our shearing tests, we observed no pore pressure change during initial (primarily elastic) shear deformation, but note a monotonic increase in pore pressure

  2. 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.

  3. Inter-laboratory consistency and variability in the buccal micronucleus cytome assay depends on biomarker scored and laboratory experience: results from the HUMNxl international inter-laboratory scoring exercise.

    PubMed

    Bolognesi, Claudia; Knasmueller, Siegfried; Nersesyan, Armen; Roggieri, Paola; Ceppi, Marcello; Bruzzone, Marco; Blaszczyk, Ewa; Mielzynska-Svach, Danuta; Milic, Mirta; Bonassi, Stefano; Benedetti, Danieli; Da Silva, Juliana; Toledo, Raphael; Salvadori, Daisy Maria Fávero; Groot de Restrepo, Helena; Filipic, Metka; Hercog, Klara; Aktas, Ayça; Burgaz, Sema; Kundi, Michael; Grummt, Tamara; Thomas, Philip; Hor, Maryam; Escudero-Fung, Maria; Holland, Nina; Fenech, Michael

    2017-03-01

    The buccal micronucleus cytome (BMNcyt) assay in uncultured exfoliated epithelial cells from oral mucosa is widely applied in biomonitoring human exposures to genotoxic agents and is also proposed as a suitable test for prescreening and follow-up of precancerous oral lesions. The main limitation of the assay is the large variability observed in the baseline values of micronuclei (MNi) and other nuclear anomalies mainly related to different scoring criteria. The aim of this international collaborative study, involving laboratories with different level of experience, was to evaluate the inter- and intra-laboratory variations in the BMNcyt parameters, using recently implemented guidelines, in scoring cells from the same pooled samples obtained from healthy subjects (control group) and from cancer patients undergoing radiotherapy (treated group). The results indicate that all laboratories correctly discriminated samples from the two groups by a significant increase of micronucleus (MN) and nuclear bud (NBUD) frequencies and differentiated binucleated (BN) cells, associated with the exposure to ionizing radiation. The experience of the laboratories was shown to play an important role in the identification of the different cell types and nuclear anomalies. MN frequency in differentiated mononucleated (MONO) and BN cells showed the greatest consistency among the laboratories and low variability was also detected in the frequencies of MONO and BN cells. A larger variability was observed in classifying the different cell types, indicating the subjectivity in the interpretation of some of the scoring criteria while reproducibility of the results between scoring sessions was very good. An inter-laboratory calibration exercise is strongly recommended before starting studies with BMNcyt assay involving multiple research centers. © The Author 2016. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions

  4. Estimation and uncertainty analysis of dose response in an inter-laboratory experiment

    NASA Astrophysics Data System (ADS)

    Toman, Blaza; Rösslein, Matthias; Elliott, John T.; Petersen, Elijah J.

    2016-02-01

    An inter-laboratory experiment for the evaluation of toxic effects of NH2-polystyrene nanoparticles on living human cancer cells was performed with five participating laboratories. Previously published results from nanocytoxicity assays are often contradictory, mostly due to challenges related to producing a reliable cytotoxicity assay protocol for use with nanomaterials. Specific challenges include reproducibility preparing nanoparticle dispersions, biological variability from testing living cell lines, and the potential for nano-related interference effects. In this experiment, such challenges were addressed by developing a detailed experimental protocol and using a specially designed 96-well plate layout which incorporated a range of control measurements to assess multiple factors such as nanomaterial interference, pipetting accuracy, cell seeding density, and instrument performance. Detailed data analysis of these control measurements showed that good control of the experiments was attained by all participants in most cases. The main measurement objective of the study was the estimation of a dose response relationship between concentration of the nanoparticles and metabolic activity of the living cells, under several experimental conditions. The dose curve estimation was achieved by imbedding a three parameter logistic curve in a three level Bayesian hierarchical model, accounting for uncertainty due to all known experimental conditions as well as between laboratory variability in a top-down manner. Computation was performed using Markov Chain Monte Carlo methods. The fit of the model was evaluated using Bayesian posterior predictive probabilities and found to be satisfactory.

  5. Do predators cause frog deformities? The need for an eco-epidemiological approach.

    PubMed

    Johnson, Pieter T J; Bowerman, Jay

    2010-11-15

    Renewed controversy has emerged over the likely causes and consequences of deformed amphibians, particularly those with missing limbs. The results of a series of experiments by Ballengée and Sessions (2009) implicate aquatic predators (i.e. dragonfly larvae) in causing such abnormalities. Skelly and Benard (2010), however, argued that the small scale of these experiments and the absence of a correlation between predator abundance and deformity frequencies in natural amphibian populations undermine such a conclusion. Drawing upon our experiences with frog malformations, we suggest that the study of amphibian deformities has been hindered by two, interrelated problems. First, empirical studies often fail to critically define the expected baseline level of abnormalities and differentiate between "epidemic" and "endemic" frequencies of malformations. Second, recognizing the likelihood of multiple causes in driving amphibian malformations, continued research needs to embrace a "multiple lines of evidence" approach that allows for complex etiologies by integrating field surveys, diagnostic pathology, comparative modeling, and experiments across a range of ecological scales. We conclude by highlighting the results of a recent study that uses this approach to identify the role of aquatic predators (i.e., fishes and dragonflies) in causing high frequencies of deformed frogs in Oregon. By combining long-term data, comparative data and mechanistic experiments, this study provides compelling evidence that certain predators do cause deformities under ecologically relevant conditions. In light of continuing concerns about amphibian deformities and population declines, we emphasize the need to integrate ecological, epidemiological, and developmental tools in addressing such environmental enigmas. Copyright © 2010 Wiley-Liss, Inc., A Wiley Company.

  6. Varying Iron Release from Transferrin and Lactoferrin Proteins. A Laboratory Experiment

    ERIC Educational Resources Information Center

    Carmona, Fernando; González, Ana; Sánchez, Manu; Gálvez, Natividad; Cuesta, Rafael; Capdevila, Mercè; Dominguez-Vera, Jose M.

    2017-01-01

    Iron metabolism is an important subject of study for undergraduate students of chemistry and biochemistry. Relevant laboratory exercises are scarce in the literature but would be very helpful in assisting students grasp key concepts. The experiment described here deals with different iron release mechanisms of two protagonists in iron metabolism:…

  7. Ideas in Practice (3): A Simulated Laboratory Experience in Digital Design.

    ERIC Educational Resources Information Center

    Cleaver, Thomas G.

    1988-01-01

    Gives an example of the use of a simplified logic simulator in a logic design course. Discusses some problems in logic design classes, commercially available software, and software problems. Describes computer-aided engineering (CAE) software. Lists 14 experiments in the simulated laboratory and presents students' evaluation of the course. (YP)

  8. 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.

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

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

    1982-01-01

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

  10. Spacetime deformation effect on the early universe and the PTOLEMY experiment

    NASA Astrophysics Data System (ADS)

    Horvat, Raul; Trampetic, Josip; You, Jiangyang

    2017-09-01

    Using a fully-fledged formulation of gauge field theory deformed by the spacetime noncommutativity, we study its impact on relic neutrino direct detection, as proposed recently by the PTOLEMY experiment. The noncommutative background tends to influence the propagating neutrinos by providing them with a tree-level vector-like coupling to photons, enabling thus otherwise sterile right-handed (RH) neutrinos to be thermally produced in the early universe. Such a new component in the universe's background radiation has been switched today to the almost fully active sea of non-relativistic neutrinos, exerting consequently some impact on the capture on tritium at PTOLEMY. The peculiarities of our nonperturbative approach tend to reflect in the cosmology as well, upon the appearances of the coupling temperature, above which RH neutrinos stay permanently decoupled from thermal environment. This entails the maximal scale of noncommutativity as well, being of order of 10-4MPl, above which there is no impact whatsoever on the capture rates at PTOLEMY. The latter represents an exceptional upper bound on the scale of noncommutativity coming from phenomenology.

  11. Analytical study on web deformation by tension in roll-to-roll printing process

    NASA Astrophysics Data System (ADS)

    Kang, Y. S.; Hong, M. S.; Lee, S. H.; Jeon, Y. H.; Kang, D.; Lee, N. K.; Lee, M. G.

    2017-08-01

    Recently, flexible devices have gained high intentions for flexible display, Radio Frequency Identification (RFID), bio-sensor and so on. For manufacturing of the flexible devices, roll-to-roll process is a good candidate because of its low production cost and high productivity. Flexible substrate has a non-uniform deformation distribution by tension. Because the roll-to-roll process carries out a number of overlay printing processes, the deformation affect overlay printing precision and printable areas. In this study, the deformation of flexible substrate was analyzed by using finite element analysis and it was verified through experiments. More deformation occurred in the middle region in the direction parallel to rolling of the flexible substrate. It is confirmed through experiments and analysis that deformation occurs less at the both ends than in the middle region. Based on these results, a hourglass roll is proposed as a mechanical design of the roll to compensate the non-uniform deformation of the flexible substrate. In the hourglass roll, high stiffness material is used in the core and low stiffness material such as an elastic material is wrapped. The diameter of the core roll was designed to be the minimum at the middle and the maximum at both ends. We tried to compensate the non-uniform deformation distribution of the flexible substrate by using the variation of the contact stiffness between the roll and the flexible substrate. Deformation distribution of flexible substrates was confirmed by finite element analysis by applying hourglass roll shape. In the analysis when using the hourglass roll, it is confirmed that the stress distribution is compensated by about 70% and the strain distribution is compensated by about 67% compared to the case using the hourglass roll. To verify the compensation of the non-uniform deformation distribution due to the tension, deformation measurement experiment when using the proposed hourglass roll was carried out

  12. 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

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

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  14. A Student Laboratory Experiment Based on the Vitamin C Clock Reaction

    ERIC Educational Resources Information Center

    Vitz, Ed

    2007-01-01

    The Vitamin C Clock Reaction has now been adapted to serve as a student laboratory experiment in the education process of high-school and college-level general chemistry. Despite of imparting valuable knowledge, it also may be hazardous, as the tincture of iodine contains inflammable substances that may cause burning on prolonged exposure.

  15. 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.

  16. Fluid-Driven Deformation of a Soft Granular Material

    NASA Astrophysics Data System (ADS)

    MacMinn, Christopher W.; Dufresne, Eric R.; Wettlaufer, John S.

    2015-01-01

    Compressing a porous, fluid-filled material drives the interstitial fluid out of the pore space, as when squeezing water out of a kitchen sponge. Inversely, injecting fluid into a porous material can deform the solid structure, as when fracturing a shale for natural gas recovery. These poromechanical interactions play an important role in geological and biological systems across a wide range of scales, from the propagation of magma through Earth's mantle to the transport of fluid through living cells and tissues. The theory of poroelasticity has been largely successful in modeling poromechanical behavior in relatively simple systems, but this continuum theory is fundamentally limited by our understanding of the pore-scale interactions between the fluid and the solid, and these problems are notoriously difficult to study in a laboratory setting. Here, we present a high-resolution measurement of injection-driven poromechanical deformation in a system with granular microsctructure: We inject fluid into a dense, confined monolayer of soft particles and use particle tracking to reveal the dynamics of the multiscale deformation field. We find that a continuum model based on poroelasticity theory captures certain macroscopic features of the deformation, but the particle-scale deformation field exhibits dramatic departures from smooth, continuum behavior. We observe particle-scale rearrangement and hysteresis, as well as petal-like mesoscale structures that are connected to material failure through spiral shear banding.

  17. Transient radon signals driven by fluid pressure pulse, micro-crack closure, and failure during granite deformation experiments

    NASA Astrophysics Data System (ADS)

    Girault, Frédéric; Schubnel, Alexandre; Pili, Éric

    2017-09-01

    In seismically active fault zones, various crustal fluids including gases are released at the surface. Radon-222, a radioactive gas naturally produced in rocks, is used in volcanic and tectonic contexts to illuminate crustal deformation or earthquake mechanisms. At some locations, intriguing radon signals have been recorded before, during, or after tectonic events, but such observations remain controversial, mainly because physical characterization of potential radon anomalies from the upper crust is lacking. Here we conducted several month-long deformation experiments under controlled dry upper crustal conditions with a triaxial cell to continuously monitor radon emission from crustal rocks affected by three main effects: a fluid pressure pulse, micro-crack closure, and differential stress increase to macroscopic failure. We found that these effects are systematically associated with a variety of radon signals that can be explained using a first-order advective model of radon transport. First, connection to a source of deep fluid pressure (a fluid pressure pulse) is associated with a large transient radon emission increase (factor of 3-7) compared with the background level. We reason that peak amplitude is governed by the accumulation time and the radon source term, and that peak duration is controlled by radioactive decay, permeability, and advective losses of radon. Second, increasing isostatic compression is first accompanied by an increase in radon emission followed by a decrease beyond a critical pressure representing the depth below which crack closure hampers radon emission (150-250 MPa, ca. 5.5-9.5 km depth in our experiments). Third, the increase of differential stress, and associated shear and volumetric deformation, systematically triggers significant radon peaks (ca. 25-350% above background level) before macroscopic failure, by connecting isolated cracks, which dramatically enhances permeability. The detection of transient radon signals before rupture

  18. Transient radon signals driven by fluid pressure pulse, micro-crack closure, and failure during granite deformation experiments

    NASA Astrophysics Data System (ADS)

    Schubnel, A.; Girault, F.; Pili, E.

    2017-12-01

    In seismically active fault zones, various crustal fluids including gases are released at the surface. Radon-222, a radioactive gas naturally produced in rocks, is used in volcanic and tectonic contexts to illuminate crustal deformation or earthquake mechanisms. At some locations, intriguing radon signals have been recorded before, during, or after tectonic events, but such observations remain controversial, mainly because physical characterization of potential radon anomalies from the upper crust is lacking. Here we conducted several month-long deformation experiments under controlled dry upper crustal conditions with a triaxial cell to continuously monitor radon emission from crustal rocks affected by three main effects: a fluid pressure pulse, micro-crack closure, and differential stress increase to macroscopic failure. We found that these effects are systematically associated with a variety of radon signals that can be explained using a first-order advective model of radon transport. First, connection to a source of deep fluid pressure (a fluid pressure pulse) is associated with a large transient radon emission increase (factor of 3-7) compared with the background level. We reason that peak amplitude is governed by the accumulation time and the radon source term, and that peak duration is controlled by radioactive decay, permeability, and advective losses of radon. Second, increasing isostatic compression is first accompanied by an increase in radon emission followed by a decrease beyond a critical pressure representing the depth below which crack closure hampers radon emission (150-250 MPa, ca. 5.5-9.5 km depth in our experiments). Third, the increase of differential stress, and associated shear and volumetric deformation, systematically triggers significant radon peaks (ca. 25-350% above background level) before macroscopic failure, by connecting isolated cracks, which dramatically enhances permeability. The detection of transient radon signals before rupture

  19. 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.

  20. Deformation processes in forging ceramics

    NASA Technical Reports Server (NTRS)

    Cannon, R. M.; Rhodes, W. H.

    1973-01-01

    The deformation processes involved in the forging of refractory ceramic oxides were investigated. A combination of mechanical testing and forging was utilized to investigate both the flow and fracture processes involved. Deformation studies of very fine grain Al203 revealed an apparent transition in behavior, characterized by a shift in the strain rate sensitivity from 0.5 at low stresses to near unity at higher stresses. The behavior is indicative of a shift in control between two dependent mechanisms, one of which is indicated to be cation limited diffusional creep with significant boundary enhancement. The possible contributions of slip, indicated by crystallographic texture, interface control of the diffusional creep and inhomogeneous boundary sliding are also discussed. Additional experiments indicated an independence of deformation behavior on MgO doping and retained hot pressing impurities, at least for ultrafine grained material, and also an independence of test atmosphere.

  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. Deformation Behavior of Recycled Concrete Aggregate during Cyclic and Dynamic Loading Laboratory Tests

    PubMed Central

    Sas, Wojciech; Głuchowski, Andrzej; Gabryś, Katarzyna; Soból, Emil; Szymański, Alojzy

    2016-01-01

    Recycled concrete aggregate (RCA) is a relatively new construction material, whose applications can replace natural aggregates. To do so, extensive studies on its mechanical behavior and deformation characteristics are still necessary. RCA is currently used as a subbase material in the construction of roads, which are subject to high settlements due to traffic loading. The deformation characteristics of RCA must, therefore, be established to find the possible fatigue and damage behavior for this new material. In this article, a series of triaxial cyclic loading and resonant column tests is used to characterize fatigue in RCA as a function of applied deviator stress after long-term cyclic loading. A description of the shakedown phenomenon occurring in the RCA and calculations of its resilient modulus (Mr) as a function of fatigue are also presented. Test result analysis with the stress-life method on the Wohler S-N diagram shows the RCA behavior in accordance with the Basquin law. PMID:28773905

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Korneev, Ph., E-mail: korneev@theor.mephi.ru; National Research Nuclear University “MEPhI”, 115409, Moscow; D'Humières, E.

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

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

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

    ERIC Educational Resources Information Center

    Duxbury, Mark

    2004-01-01

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

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

    ERIC Educational Resources Information Center

    Baltzis, Konstantinos B.; Koukias, Konstantinos D.

    2009-01-01

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

  7. Laboratory Modelling of Volcano Plumbing Systems: a review

    NASA Astrophysics Data System (ADS)

    Galland, Olivier; Holohan, Eoghan P.; van Wyk de Vries, Benjamin; Burchardt, Steffi

    2015-04-01

    Earth scientists have, since the XIX century, tried to replicate or model geological processes in controlled laboratory experiments. In particular, laboratory modelling has been used study the development of volcanic plumbing systems, which sets the stage for volcanic eruptions. Volcanic plumbing systems involve complex processes that act at length scales of microns to thousands of kilometres and at time scales from milliseconds to billions of years, and laboratory models appear very suitable to address them. This contribution reviews laboratory models dedicated to study the dynamics of volcano plumbing systems (Galland et al., Accepted). The foundation of laboratory models is the choice of relevant model materials, both for rock and magma. We outline a broad range of suitable model materials used in the literature. These materials exhibit very diverse rheological behaviours, so their careful choice is a crucial first step for the proper experiment design. The second step is model scaling, which successively calls upon: (1) the principle of dimensional analysis, and (2) the principle of similarity. The dimensional analysis aims to identify the dimensionless physical parameters that govern the underlying processes. The principle of similarity states that "a laboratory model is equivalent to his geological analogue if the dimensionless parameters identified in the dimensional analysis are identical, even if the values of the governing dimensional parameters differ greatly" (Barenblatt, 2003). The application of these two steps ensures a solid understanding and geological relevance of the laboratory models. In addition, this procedure shows that laboratory models are not designed to exactly mimic a given geological system, but to understand underlying generic processes, either individually or in combination, and to identify or demonstrate physical laws that govern these processes. From this perspective, we review the numerous applications of laboratory models to

  8. Incrementally Approaching an Inquiry Lab Curriculum: Can Changing a Single Laboratory Experiment Improve Student Performance in General Chemistry?

    ERIC Educational Resources Information Center

    Cacciatore, Kristen L.; Sevian, Hannah

    2009-01-01

    Many institutions are responding to current research about how students learn science by transforming their general chemistry laboratory curricula to be inquiry-oriented. We present a comparison study of student performance after completing either a traditional or an inquiry stoichiometry experiment. This single laboratory experience was the only…

  9. 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)

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

    ERIC Educational Resources Information Center

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

    2005-01-01

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

  11. Cyclic deformation of bidisperse two-dimensional foams

    NASA Astrophysics Data System (ADS)

    Fátima Vaz, M.; Cox, S. J.; Teixeira, P. I. C.

    2011-12-01

    In-plane deformation of foams was studied experimentally by subjecting bidisperse foams to cycles of traction and compression at a prescribed rate. Each foam contained bubbles of two sizes with given area ratio and one of three initial arrangements: sorted perpendicular to the axis of deformation (iso-strain), sorted parallel to the axis of deformation (iso-stress), or randomly mixed. Image analysis was used to measure the characteristics of the foams, including the number of edges separating small from large bubbles N sl , the perimeter (surface energy), the distribution of the number of sides of the bubbles, and the topological disorder μ2(N). Foams that were initially mixed were found to remain mixed after the deformation. The response of sorted foams, however, depended on the initial geometry, including the area fraction of small bubbles and the total number of bubbles. For a given experiment we found that (i) the perimeter of a sorted foam varied little; (ii) each foam tended towards a mixed state, measured through the saturation of N sl ; and (iii) the topological disorder μ2(N) increased up to an "equilibrium" value. The results of different experiments showed that (i) the change in disorder, ? decreased with the area fraction of small bubbles under iso-strain, but was independent of it under iso-stress; and (ii) ? increased with ? under iso-strain, but was again independent of it under iso-stress. We offer explanations for these effects in terms of elementary topological processes induced by the deformations that occur at the bubble scale.

  12. Laboratory Experiments on Meandering Meltwater Channels

    NASA Astrophysics Data System (ADS)

    Fernandez, R.; Berens, J.; Parker, G.; Stark, C. P.

    2017-12-01

    Meandering channels of all scales and flowing over a wide variety of media have common planform patterns. Although the analogy in planform suggests there is a common underlying framework, the constitutive relations driving planform evolution through vertical incision/deposition and lateral migration differ from medium to medium. The driving processes in alluvial and mixed bedrock-alluvial meandering channels have been studied substantially over the last decades. However, this is not the case for meandering channels in other media such as ice or soluble rock. Here we present results from experiments conducted at the Ven Te Chow Hydrosystems Laboratory of the University of Illinois at Urbana-Champaign on meltwater meandering channels. A rivulet is carved into an ice block and water is allowed to flow at a constant discharge. Planform evolution is analyzed with time lapse imaging and complemented with rubber molds of the channel once the experiment is over. These molds give us the full 3D structure of the meandering, including incisional overhang. Vertical incision rates are measured throughout the run by taking elevations along the channel, and these measurements are complemented with analysis from the molds. We show examples of meandering of intense amplitude with deep overhangs. Features resembling scroll bars document cyclically punctuated melting. We report on lateral migration rates, incision rates, sinuosity, channel depths, channel widths, reach averaged velocities, bend wavelengths and amplitudes and compare them to values reported in the literature for alluvial rivers.

  13. X-Ray Diffraction of Intermetallic Compounds: A Physical Chemistry Laboratory Experiment

    ERIC Educational Resources Information Center

    Varberg, Thomas D.; Skakuj, Kacper

    2015-01-01

    Here we describe an experiment for the undergraduate physical chemistry laboratory in which students synthesize the intermetallic compounds AlNi and AlNi3 and study them by X-ray diffractometry. The compounds are synthesized in a simple one-step reaction occurring in the solid state. Powder X-ray diffractograms are recorded for the two compounds…

  14. Stresses, deformation, and seismic events on scaled experimental faults with heterogeneous fault segments and comparison to numerical modeling

    NASA Astrophysics Data System (ADS)

    Buijze, Loes; Guo, Yanhuang; Niemeijer, André R.; Ma, Shengli; Spiers, Christopher J.

    2017-04-01

    Faults in the upper crust cross-cut many different lithologies, which cause the composition of the fault rocks to vary. Each different fault rock segment may have specific mechanical properties, e.g. there may be stronger and weaker segments, and segments prone to unstable slip or creeping. This leads to heterogeneous deformation and stresses along such faults, and a heterogeneous distribution of seismic events. We address the influence of fault variability on stress, deformation, and seismicity using a combination of scaled laboratory fault and numerical modeling. A vertical fault was created along the diagonal of a 30 x 20 x 5 cm block of PMMA, along which a 2 mm thick gouge layer was deposited. Gouge materials of different characteristics were used to create various segments along the fault; quartz (average strength, stable sliding), kaolinite (weak, stable sliding), and gypsum (average strength, unstable sliding). The sample assembly was placed in a horizontal biaxial deformation apparatus, and shear displacement was enforced along the vertical fault. Multiple observations were made: 1) Acoustic emissions were continuously recorded at 3 MHz to observe the occurrence of stick-slips (micro-seismicity), 2) Photo-elastic effects (indicative of the differential stress) were recorded in the transparent set of PMMA wall-rocks using a high-speed camera, and 3) particle tracking was conducted on a speckle painted set of PMMA wall-rocks to study the deformation in the wall-rocks flanking the fault. All three observation methods show how the heterogeneous fault gouge exerts a strong control on the fault behavior. For example, a strong, unstable segment of gypsum flanked by two weaker kaolinite segments show strong stress concentrations develop near the edges of the strong segment, with at the same time most of acoustic emissions being located at the edge of this strong segment. The measurements of differential stress, strain and acoustic emissions provide a strong means

  15. Large-deformation and high-strength amorphous porous carbon nanospheres

    NASA Astrophysics Data System (ADS)

    Yang, Weizhu; Mao, Shimin; Yang, Jia; Shang, Tao; Song, Hongguang; Mabon, James; Swiech, Wacek; Vance, John R.; Yue, Zhufeng; Dillon, Shen J.; Xu, Hangxun; Xu, Baoxing

    2016-04-01

    Carbon is one of the most important materials extensively used in industry and our daily life. Crystalline carbon materials such as carbon nanotubes and graphene possess ultrahigh strength and toughness. In contrast, amorphous carbon is known to be very brittle and can sustain little compressive deformation. Inspired by biological shells and honeycomb-like cellular structures in nature, we introduce a class of hybrid structural designs and demonstrate that amorphous porous carbon nanospheres with a thin outer shell can simultaneously achieve high strength and sustain large deformation. The amorphous carbon nanospheres were synthesized via a low-cost, scalable and structure-controllable ultrasonic spray pyrolysis approach using energetic carbon precursors. In situ compression experiments on individual nanospheres show that the amorphous carbon nanospheres with an optimized structure can sustain beyond 50% compressive strain. Both experiments and finite element analyses reveal that the buckling deformation of the outer spherical shell dominates the improvement of strength while the collapse of inner nanoscale pores driven by twisting, rotation, buckling and bending of pore walls contributes to the large deformation.

  16. 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.

  17. Experiences of Mentors Training Underrepresented Undergraduates in the Research Laboratory

    PubMed Central

    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. PMID:24006389

  18. An analysis of high school students' perceptions and academic performance in laboratory experiences

    NASA Astrophysics Data System (ADS)

    Mirchin, Robert Douglas

    This research study is an investigation of student-laboratory (i.e., lab) learning based on students' perceptions of experiences using questionnaire data and evidence of their science-laboratory performance based on paper-and-pencil assessments using Maryland-mandated criteria, Montgomery County Public Schools (MCPS) criteria, and published laboratory questions. A 20-item questionnaire consisting of 18 Likert-scale items and 2 open-ended items that addressed what students liked most and least about lab was administered to students before labs were observed. A pre-test and post-test assessing laboratory achievement were administered before and after the laboratory experiences. The three labs observed were: soda distillation, stoichiometry, and separation of a mixture. Five significant results or correlations were found. For soda distillation, there were two positive correlations. Student preference for analyzing data was positively correlated with achievement on the data analysis dimension of the lab rubric. A student preference for using numbers and graphs to analyze data was positively correlated with achievement on the analysis dimension of the lab rubric. For the separating a mixture lab data the following pairs of correlations were significant. Student preference for doing chemistry labs where numbers and graphs were used to analyze data had a positive correlation with writing a correctly worded hypothesis. Student responses that lab experiences help them learn science positively correlated with achievement on the data dimension of the lab rubric. The only negative correlation found related to the first result where students' preference for computers was inversely correlated to their performance on analyzing data on their lab report. Other findings included the following: students like actual experimental work most and the write-up and analysis of a lab the least. It is recommended that lab science instruction be inquiry-based, hands-on, and that students be

  19. Craniofacial neurofibromatosis: treatment of the midface deformity.

    PubMed

    Singhal, Dhruv; Chen, Yi-Chieh; Tsai, Yueh-Ju; Yu, Chung-Chih; Chen, Hung Chang; Chen, Yu-Ray; Chen, Philip Kuo-Ting

    2014-07-01

    Craniofacial Neurofibromatosis is a benign but devastating disease. While the most common location of facial involvement is the orbito-temporal region, patients often present with significant mid-face deformities. We reviewed our experience with Craniofacial Neurofibromatosis from June 1981 to June 2011 and included patients with midface soft tissue deformities defined as gross alteration of nasal or upper lip symmetry. Data reviewed included the medical records and photobank. Over 30 years, 52 patients presented to and underwent surgical management for Craniofacial Neurofibromatosis at the Chang Gung Craniofacial Center. 23 patients (43%) demonstrated gross mid-facial deformities at initial evaluation. 55% of patients with lip deformities and 28% of patients with nasal deformities demonstrated no direct tumour involvement. The respective deformity was solely due to secondary gravitational effects from neurofibromas of the cheek subunit. Primary tumour infiltration of the nasal and/or labial subunits was treated with excision followed by various methods of reconstruction including lower lateral cartilage repositioning, forehead flaps, free flaps, and/or oral commissure suspension. Soft tissue deformities of the midface are very common in patients with Craniofacial Neurofibromatosis and profoundly affect overall aesthetic outcomes. Distinguishing primary from secondary involvement of the midface assists in surgical decision making. Copyright © 2013 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  20. Whitson looks at the ADVASC Soybean plant growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-07-10

    ISS005-E-07212 (10 July 2002) --- NASA Astronaut Peggy Whitson, Expedition 5 International Space Station (ISS) science officer, looks at the Advanced Astroculture (ADVASC) Soybean plant growth experiment as part of Expediting the Process of Experiments to the Space Station (EXPRESS) Rack 4 located in the U.S. Laboratory Destiny.

  1. AV Instructional Materials Manual; A Sslf-Instructional Guide to AV Laboratory Experiences. Third Edition.

    ERIC Educational Resources Information Center

    Brown, James W., Ed.; Lewis, Richard B., Ed.

    This self-instructional guide to audiovisual laboratory experiences contains 50 exercises designed to give the user active experiences in the practical problems of choosing, using, and inventing instructional materials and in operating and audiovisual equipment. With the exception of the first four exercises (which introduce the user to the manual…

  2. Monitoring Seawall Deformation With Repeat-Track Space-Borne SAR Images

    NASA Astrophysics Data System (ADS)

    Pei, Yuanyuan; Wan, Qing; Wei, Lianhuan; Fang, Zhilei; Liao, Mingsheng

    2010-10-01

    Seawalls are constructed to protect coastal cities from typhoon, flood and sea tide. It is necessary to monitor the deformation of seawalls in real time. Repeat-track space-borne SAR images are useful for environment monitoring, especially ground deformation monitoring. Shanghai sits on the Yangtze River Delta on China's eastern coast. Each year, the city is hit by typhoons from Pacific Ocean and threatened by the flood of the Yangtze River. PS-InSAR technique is carried out to monitor the deformation of the seawalls. Experiment exhibits that the seawalls around Pudong airport and Lingang town suffered serious deformation.

  3. Magnetic anisotropy and magnetite textures from experimental shear deformation

    NASA Astrophysics Data System (ADS)

    Till, Jessica; Moskowitz, Bruce

    2015-04-01

    Magnetite is a common accessory mineral in crustal rocks and exerts a dominant influence on the magnetic anisotropy of rocks when present. Therefore the deformation behavior of magnetite strongly determines how magnetic fabric develops with increasing strain in a deforming rock. Here we show results from experimental deformation of magnetite-silicate aggregates in high-temperature transpressional shear experiments (1000-1200°C) under moderate shear stresses (10-130 MPa) using a gas-medium deformation apparatus. Anisotropy of magnetic susceptibility, shape preferred orientation (SPO) of magnetite, and electron backscatter diffraction (EBSD) were each used to characterize the magnetite deformation fabrics and intragrain microstructures. Magnetic anisotropy and SPO each increase strongly with increasing strain, which ranged between 100-300%. An interesting feature of the deformation fabrics is that both magnetite SPO and magnetic fabric intensity are stronger at higher temperatures, indicating that strain partitioning between magnetite and the plagioclase matrix decreases at higher temperatures. Although flow laws for magnetite predict it to be weaker than dry plagioclase at the experimental conditions, the temperature-dependence of the fabric strength indicates that magnetite is more viscous than the "wet" plagioclase used in the experiments. In contrast to the magnetic and shape fabrics, crystallographic preferred orientation (CPO) of magnetite is very weak in all deformed samples. In EBSD orientation mapping of individual particles, incipient subgrain boundary formation is evident in magnetite grains, indicating that dislocation creep processes were active in magnetite despite the lack of a well-developed CPO. The weak magnetite CPOs are primarily attributed to multiple slip systems acting in parallel. These findings support the observations of previous studies that crystallographic textures in cubic minerals such as magnetite may be inherently weak or slow to

  4. Analyzing Inquiry Questions of High-School Students in a Gas Chromatography Open-Ended Laboratory Experiment

    ERIC Educational Resources Information Center

    Blonder, Ron; Mamlock-Naaman, Rachel; Hofstein, Avi

    2008-01-01

    This paper describes the implementation of an open-ended inquiry experiment for high-school students, based on gas chromatography (GC). The research focuses on identifying the level of questions that students ask during the GC open inquiry laboratory, and it examines whether implementing the advanced inquiry laboratory opens up new directions for…

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

    ERIC Educational Resources Information Center

    Feist, Patty L.

    2008-01-01

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

  6. Grain size and shape evolution of experimentally deformed sediments: the role of slip rate

    NASA Astrophysics Data System (ADS)

    Balsamo, Fabrizio; Storti, Fabrizio; De Paola, Nicola

    2016-04-01

    Sediment deformation within fault zones occurs with a broad spectrum of mechanisms which, in turn, depend on intrinsic material properties (porosity, grain size and shape, etc.) and external factors (burial depth, fluid pressure, stress configuration, etc.). Fieldworks and laboratory measurements conducted in the last years in sediments faulted at shallow depth showed that cataclasis and grain size reduction can occur very close to the Earth surface (<1-2 km), and that fault displacement is one of the parameters controlling the amount of grain size, shape, and microtextural modifications in fault cores. In this contribution, we present a new set of microstructural observations combined with grain size and shape distribution data obtained from quart-feldspatic loose sediments (mean grain diameter 0.2 mm) experimentally deformed at different slip rates from subseismic (0.01 mm/s, 0.1 mm/s, 1 mm/s, 1 cm/s, and 10 cm/s) to coseismic slip rates (1 m/s). The experiments were originally performed at sigma n=14 MPa, with the same amount of slip (1.3 m), to constrain the frictional properties of such sediments at shallow confining pressures (<1 km). After the experiments, the granular materials deformed in the 0.1-1 mm-thick slip zones were prepared for both grain size distribution analyses and microstructural and textural analyses in thin sections. Grain size distribution analyses were obtained with a Malvern Mastersizer 3000 particle size laser-diffraction analyser, whereas grain shape data (angularity) were obtained by using image analysis technique on selected SEM-photomicrographs. Microstructural observations were performed at different scales with a standard optical microscope and with a SEM. Results indicate that mean grain diameter progressively decreases with increasing slip rates up to ~20-30 m, and that granulometric curves systematically modify as well, shifting toward finer grain sizes. Obtained fractal dimensions (D) indicate that D increases from ~2.3 up

  7. Whitson holds the ADVASC Soybean plant growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-07-10

    ISS005-E-07209 (10 July 2002) --- Astronaut Peggy A. Whitson, Expedition Five NASA ISS science officer, holds the Advanced Astroculture soybean plant growth experiment in the Destiny laboratory on the International Space Station (ISS).

  8. A Microfluidic Technique to Probe Cell Deformability

    PubMed Central

    Hoelzle, David J.; Varghese, Bino A.; Chan, Clara K.; Rowat, Amy C.

    2014-01-01

    Here we detail the design, fabrication, and use of a microfluidic device to evaluate the deformability of a large number of individual cells in an efficient manner. Typically, data for ~102 cells can be acquired within a 1 hr experiment. An automated image analysis program enables efficient post-experiment analysis of image data, enabling processing to be complete within a few hours. Our device geometry is unique in that cells must deform through a series of micron-scale constrictions, thereby enabling the initial deformation and time-dependent relaxation of individual cells to be assayed. The applicability of this method to human promyelocytic leukemia (HL-60) cells is demonstrated. Driving cells to deform through micron-scale constrictions using pressure-driven flow, we observe that human promyelocytic (HL-60) cells momentarily occlude the first constriction for a median time of 9.3 msec before passaging more quickly through the subsequent constrictions with a median transit time of 4.0 msec per constriction. By contrast, all-trans retinoic acid-treated (neutrophil-type) HL-60 cells occlude the first constriction for only 4.3 msec before passaging through the subsequent constrictions with a median transit time of 3.3 msec. This method can provide insight into the viscoelastic nature of cells, and ultimately reveal the molecular origins of this behavior. PMID:25226269

  9. Pyranometer offsets triggered by ambient meteorology: insights from laboratory and field experiments

    NASA Astrophysics Data System (ADS)

    Oswald, Sandro M.; Pietsch, Helga; Baumgartner, Dietmar J.; Weihs, Philipp; Rieder, Harald E.

    2017-03-01

    This study investigates the effects of ambient meteorology on the accuracy of radiation (R) measurements performed with pyranometers contained in various heating and ventilation systems (HV-systems). It focuses particularly on instrument offsets observed following precipitation events. To quantify pyranometer responses to precipitation, a series of controlled laboratory experiments as well as two targeted field campaigns were performed in 2016. The results indicate that precipitation (as simulated by spray tests or observed under ambient conditions) significantly affects the thermal environment of the instruments and thus their stability. Statistical analyses of laboratory experiments showed that precipitation triggers zero offsets of -4 W m-2 or more, independent of the HV-system. Similar offsets were observed in field experiments under ambient environmental conditions, indicating a clear exceedance of BSRN (Baseline Surface Radiation Network) targets following precipitation events. All pyranometers required substantial time to return to their initial signal states after the simulated precipitation events. Therefore, for BSRN-class measurements, the recommendation would be to flag the radiation measurements during a natural precipitation event and 90 min after it in nighttime conditions. Further daytime experiments show pyranometer offsets of 50 W m-2 or more in comparison to the reference system. As they show a substantially faster recovery, the recommendation would be to flag the radiation measurements within a natural precipitation event and 10 min after it in daytime conditions.

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  11. Field versus laboratory experiments to evaluate the fate of azoxystrobin in an amended vineyard soil.

    PubMed

    Herrero-Hernández, E; Marín-Benito, J M; Andrades, M S; Sánchez-Martín, M J; Rodríguez-Cruz, M S

    2015-11-01

    This study reports the effect that adding spent mushroom substrate (SMS) to a representative vineyard soil from La Rioja region (Spain) has on the behaviour of azoxystrobin in two different environmental scenarios. Field dissipation experiments were conducted on experimental plots amended at rates of 50 and 150 t ha(-1), and similar dissipation experiments were simultaneously conducted in the laboratory to identify differences under controlled conditions. Azoxystrobin dissipation followed biphasic kinetics in both scenarios, although the initial dissipation phase was much faster in the field than in the laboratory experiments, and the half-life (DT50) values obtained in the two experiments were 0.34-46.3 days and 89.2-148 days, respectively. Fungicide residues in the soil profile increased in the SMS amended soil and they were much higher in the top two layers (0-20 cm) than in deeper layers. The persistence of fungicide in the soil profile is consistent with changes in azoxystrobin adsorption by unamended and amended soils over time. Changes in the dehydrogenase activity (DHA) of soils under different treatments assayed in the field and in the laboratory indicated that SMS and the fungicide had a stimulatory effect on soil DHA. The results reveal that the laboratory studies usually reported in the literature to explain the fate of pesticides in amended soils are insufficient to explain azoxystrobin behaviour under real conditions. Field studies are necessary to set up efficient applications of SMS and fungicide, with a view to preventing the possible risk of water contamination. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. 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.

  13. Relative scale and the strength and deformability of rock masses

    NASA Astrophysics Data System (ADS)

    Schultz, Richard A.

    1996-09-01

    The strength and deformation of rocks depend strongly on the degree of fracturing, which can be assessed in the field and related systematically to these properties. Appropriate Mohr envelopes obtained from the Rock Mass Rating (RMR) classification system and the Hoek-Brown criterion for outcrops and other large-scale exposures of fractured rocks show that rock-mass cohesive strength, tensile strength, and unconfined compressive strength can be reduced by as much as a factor often relative to values for the unfractured material. The rock-mass deformation modulus is also reduced relative to Young's modulus. A "cook-book" example illustrates the use of RMR in field applications. The smaller values of rock-mass strength and deformability imply that there is a particular scale of observation whose identification is critical to applying laboratory measurements and associated failure criteria to geologic structures.

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

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  15. Lattice preferred orientation of hcp-iron induced by shear deformation

    NASA Astrophysics Data System (ADS)

    Nishihara, Y.; Ohuchi, T.; Kawazoe, T.; Maruyama, G.; Higo, Y.; Funakoshi, K. I.; Seto, Y.

    2015-12-01

    Many hypotheses have been proposed for origin of seismic anisotropy in the Earth's inner core which consists of solid metal. Plastic deformation of constituent material (most probably hexagonal-close-packed (hcp) iron) is one of the candidate processes to form the inner core anisotropy. Thus knowledge of deformation-induced lattice preferred orientation (LPO) of hcp-iron is important for understanding of nature of the inner core. In this study, we have carried out shear deformation experiments on hcp-iron and determined its deformation induced LPO. Since it is impossible to recover hcp-iron to ambient condition, both deformation and measurement of LPO have to be done at high-pressure conditions. Shear deformation experiments of hcp-iron were carried out using a deformation-DIA apparatus at high-pressure and high-temperature condition where hcp-iron is stable (9-18 GPa, 723 K). Development of LPO in the deforming sample was observed in-situ based on two-dimensional X-ray diffraction using an imaging plate detector and monochromatized synchrotron X-ray. In shear deformation of hcp-iron, <0001> and <112‾0> axes gradually aligned to be sub-parallel to shear plane normal and shear direction, respectively, from initial random orientation. The <0001> and <112‾0> axes are back-rotated from shear direction by 30°. The above results suggest basal slip <112‾0>{0001} is the dominant slip system under the studied deformation conditions. It has been shown that Earth's inner core has an axisymmetric anisotropy with P-wave traveling 3% faster along polar paths than along equatorial directions. Although elastic anisotropy of hcp-iron at the inner core conditions is still controversial, recent theoretical studies consistently shows that P-wave velocity of hcp-iron is fastest along <0001> direction at least at low-temperatures. Our experimental results could be suggesting that most part of the inner core deforms with shear plane sub-parallel to equatorial plane.

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

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  17. 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. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  18. Design of an Orthodontic Torque Simulator for Measurement of Bracket Deformation

    NASA Astrophysics Data System (ADS)

    Melenka, G. W.; Nobes, D. S.; Major, P. W.; Carey, J. P.

    2013-12-01

    The design and testing of an orthodontic torque simulator that reproduces the effect of archwire rotation on orthodontic brackets is described. This unique device is capable of simultaneously measuring the deformation and loads applied to an orthodontic bracket due to archwire rotation. Archwire rotation is used by orthodontists to correct the inclination of teeth within the mouth. This orthodontic torque simulator will provide knowledge of the deformation and loads applied to orthodontic bracket that will aide clinicians by describing the effect of archwire rotation on brackets. This will also impact that design on new archwirebracket systems by providing an assessment of performance. Deformation of the orthodontic bracket tie wings is measured using a digital image correlation process to measure elastic and plastic deformation. The magnitude of force and moments applied to the bracket though the archwire is also measured using a six-axis load cell. Initial tests have been performed on two orthodontic brackets of varying geometry to demonstrate the measurement capability of the orthodontic torque simulator. The demonstration experiment shows that a Damon Q bracket had a final plastic deformation after a single loading of 0.022 mm while the Speed bracket deformed 0.071 mm. This indicates that the Speed bracket plastically deforms 3.2 times more than the Damon Q bracket for similar magnitude of applied moment. The demonstration experiment demonstrates that bracket geometry affect the deformation of orthodontic brackets and this difference can be detected using the orthodontic torque simulator.

  19. Summer Research Experiences with a Laboratory Tokamak

    NASA Astrophysics Data System (ADS)

    Farley, N.; Mauel, M.; Navratil, G.; Cates, C.; Maurer, D.; Mukherjee, S.; Shilov, M.; Taylor, E.

    1998-11-01

    Columbia University's Summer Research Program for Secondary School Science Teachers seeks to improve middle and high school student understanding of science. The Program enhances science teachers' understanding of the practice of science by having them participate for two consecutive summers as members of laboratory research teams led by Columbia University faculty. In this poster, we report the research and educational activities of two summer internships with the HBT-EP research tokamak. Research activities have included (1) computer data acquisition and the representation of complex plasma wave phenomena as audible sounds, and (2) the design and construction of pulsed microwave systems to experience the design and testing of special-purpose equipment in order to achieve a specific technical goal. We also present an overview of the positive impact this type of plasma research involvement has had on high school science teaching.

  20. The Synthetic Experiment: E. B. Titchener's Cornell Psychological Laboratory and the Test of Introspective Analysis.

    PubMed

    Evans, Rand B

    2017-01-01

    Beginning in 1 9a0, a major thread of research was added to E. B. Titchener's Cornell laboratory: the synthetic experiment. Titchener and his graduate students used introspective analysis to reduce a perception, a complex experience, into its simple sensory constituents. To test the validity of that analysis, stimulus patterns were selected to reprodiuce the patterns of sensations found in the introspective analyses. If the original perception can be reconstructed in this way, then the analysis was considered validated. This article reviews development of the synthetic method in E. B. Titchener's laboratory at Cornell University and examines its impact on psychological research.

  1. Estimation of contour motion and deformation for nonrigid object tracking

    NASA Astrophysics Data System (ADS)

    Shao, Jie; Porikli, Fatih; Chellappa, Rama

    2007-08-01

    We present an algorithm for nonrigid contour tracking in heavily cluttered background scenes. Based on the properties of nonrigid contour movements, a sequential framework for estimating contour motion and deformation is proposed. We solve the nonrigid contour tracking problem by decomposing it into three subproblems: motion estimation, deformation estimation, and shape regulation. First, we employ a particle filter to estimate the global motion parameters of the affine transform between successive frames. Then we generate a probabilistic deformation map to deform the contour. To improve robustness, multiple cues are used for deformation probability estimation. Finally, we use a shape prior model to constrain the deformed contour. This enables us to retrieve the occluded parts of the contours and accurately track them while allowing shape changes specific to the given object types. Our experiments show that the proposed algorithm significantly improves the tracker performance.

  2. Deformation behavior of HCP titanium alloy: Experiment and Crystal plasticity modeling

    DOE PAGES

    Wronski, M.; Arul Kumar, Mariyappan; Capolungo, Laurent; ...

    2018-03-02

    The deformation behavior of commercially pure titanium is studied using experiments and a crystal plasticity model. Compression tests along the rolling, transverse, and normal-directions, and tensile tests along the rolling and transverse directions are performed at room temperature to study the activation of slip and twinning in the hexagonal closed packed titanium. A detailed EBSD based statistical analysis of the microstructure is performed to develop statistics of both {10-12} tensile and {11-22} compression twins. A simple Monte Carlo (MC) twin variant selection criterion is proposed within the framework of the visco-plastic self-consistent (VPSC) model with a dislocation density (DD) basedmore » law used to describe dislocation hardening. In the model, plasticity is accommodated by prismatic, basal and pyramidal slip modes, and {10-12} tensile and {11-22} compression twinning modes. Thus, the VPSC-MC model successfully captures the experimentally observed activation of low Schmid factor twin variants for both tensile and compression twins modes. The model also predicts macroscopic stress-strain response, texture evolution and twin volume fraction that are in agreement with experimental observations.« less

  3. Deformation behavior of HCP titanium alloy: Experiment and Crystal plasticity modeling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wronski, M.; Arul Kumar, Mariyappan; Capolungo, Laurent

    The deformation behavior of commercially pure titanium is studied using experiments and a crystal plasticity model. Compression tests along the rolling, transverse, and normal-directions, and tensile tests along the rolling and transverse directions are performed at room temperature to study the activation of slip and twinning in the hexagonal closed packed titanium. A detailed EBSD based statistical analysis of the microstructure is performed to develop statistics of both {10-12} tensile and {11-22} compression twins. A simple Monte Carlo (MC) twin variant selection criterion is proposed within the framework of the visco-plastic self-consistent (VPSC) model with a dislocation density (DD) basedmore » law used to describe dislocation hardening. In the model, plasticity is accommodated by prismatic, basal and pyramidal slip modes, and {10-12} tensile and {11-22} compression twinning modes. Thus, the VPSC-MC model successfully captures the experimentally observed activation of low Schmid factor twin variants for both tensile and compression twins modes. The model also predicts macroscopic stress-strain response, texture evolution and twin volume fraction that are in agreement with experimental observations.« less

  4. Elastic plastic self-consistent (EPSC) modeling of plastic deformation in fayalite olivine

    DOE PAGES

    Burnley, Pamela C

    2015-07-01

    Elastic plastic self-consistent (EPSC) simulations are used to model synchrotron X-ray diffraction observations from deformation experiments on fayalite olivine using the deformation DIA apparatus. Consistent with results from other in situ diffraction studies of monomineralic polycrystals, the results show substantial variations in stress levels among grain populations. Rather than averaging the lattice reflection stresses or choosing a single reflection to determine the macroscopic stress supported by the specimen, an EPSC simulation is used to forward model diffraction data and determine a macroscopic stress that is consistent with lattice strains of all measured diffraction lines. The EPSC simulation presented here includesmore » kink band formation among the plastic deformation mechanisms in the simulation. The inclusion of kink band formation is critical to the success of the models. This study demonstrates the importance of kink band formation as an accommodation mechanism during plastic deformation of olivine as well as the utility of using EPSC models to interpret diffraction from in situ deformation experiments.« less

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

    ERIC Educational Resources Information Center

    Splittgerber, A. G.; Sohl, Julie

    1988-01-01

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

  6. Deformation behaviors of peat with influence of organic matter.

    PubMed

    Yang, Min; Liu, Kan

    2016-01-01

    Peat is a kind of special material rich in organic matter. Because of the high content of organic matter, it shows different deformation behaviors from conventional geotechnical materials. Peat grain has a non-negligible compressibility due to the presence of organic matter. Biogas can generate from peat and can be trapped in form of gas bubbles. Considering the natural properties of peat, a special three-phase composition of peat is described which indicates the existence of organic matter and gas bubbles in peat. A stress-strain-time model is proposed for the compression of organic matter, and the surface tension effect is considered in the compression model of gas bubbles. Finally, a mathematical model has been developed to simulate the deformation behavior of peat considering the compressibility of organic matter and entrapped gas bubbles. The deformation process is the coupling of volume variation of organic matter, gas bubbles and water drainage. The proposed model is used to simulate a series of peat laboratory oedometer tests, and the model can well capture the test results with reasonable model parameters. Effects of model parameters on deformation of peat are also analyzed.

  7. Characterization of plastic deformation and chemical reaction in titanium-polytetrafluoroethylene mixture

    NASA Astrophysics Data System (ADS)

    Davis, Jeffery Jon

    1998-09-01

    The subject of this dissertation is the deformation process of a single metal - polymer system (titanium - polytetrafluoroethylene) and how this process leads to initiation of chemical reaction. Several different kinds of experiments were performed to characterize the behavior of this material to shock and impact. These mechanical conditions induce a rapid plastic deformation of the sample. All of the samples tested had an initial porosity which increased the plastic flow condition. It is currently believed that during the deformation process two important conditions occur: removal of the oxide layer from the metal and decomposition of the polymer. These conditions allow for rapid chemical reaction. The research from this dissertation has provided insight into the complex behavior of plastic deformation and chemical reactions in titanium - polytetrafluoroethylene (PTFE, Teflon). A hydrodynamic computational code was used to model the plastic flow for correlation with the results from the experiments. The results from this work are being used to develop an ignition and growth model for metal/polymer systems. Three sets of experiments were used to examine deformation of the 80% Ti and 20% Teflon materials: drop- weight, gas gun, and split-Hopkinson pressure bar. Recovery studies included post shot analysis of the samples using x-ray diffraction. Lagrangian hydrocode DYNA2D modeling of the drop-weight tests was performed for comparison with experiments. One of the reactions know to occur is Ti + C → TiC (s) which results in an exothermic release. However, the believed initial reactions occur between Ti and fluorine which produces TixFy gases. The thermochemical code CHEETAH was used to investigate the detonation products and concentrations possible during Ti - Teflon reaction. CHEETAH shows that the Ti - fluorine reactions are thermodynamically favorable. This research represents the most comprehensive to date study of deformation induced chemical reaction in metal/polymers.

  8. Quantification of abdominal aortic deformation after EVAR

    NASA Astrophysics Data System (ADS)

    Demirci, Stefanie; Manstad-Hulaas, Frode; Navab, Nassir

    2009-02-01

    Quantification of abdominal aortic deformation is an important requirement for the evaluation of endovascular stenting procedures and the further refinement of stent graft design. During endovascular aortic repair (EVAR) treatment, the aortic shape is subject to severe deformation that is imposed by medical instruments such as guide wires, catheters, and, the stent graft. This deformation can affect the flow characteristics and morphology of the aorta which have been shown to be elicitors for stent graft failures and be reason for reappearance of aneurysms. We present a method for quantifying the deformation of an aneurysmatic aorta imposed by an inserted stent graft device. The outline of the procedure includes initial rigid alignment of the two abdominal scans, segmentation of abdominal vessel trees, and automatic reduction of their centerline structures to one specified region of interest around the aorta. This is accomplished by preprocessing and remodeling of the pre- and postoperative aortic shapes before performing a non-rigid registration. We further narrow the resulting displacement fields to only include local non-rigid deformation and therefore, eliminate all remaining global rigid transformations. Finally, deformations for specified locations can be calculated from the resulting displacement fields. In order to evaluate our method, experiments for the extraction of aortic deformation fields are conducted on 15 patient datasets from endovascular aortic repair (EVAR) treatment. A visual assessment of the registration results and evaluation of the usage of deformation quantification were performed by two vascular surgeons and one interventional radiologist who are all experts in EVAR procedures.

  9. Expression, Purification, and Characterization of a Carbohydrate-Active Enzyme: A Research-Inspired Methods Optimization Experiment for the Biochemistry Laboratory

    ERIC Educational Resources Information Center

    Willbur, Jaime F.; Vail, Justin D.; Mitchell, Lindsey N.; Jakeman, David L.; Timmons, Shannon C.

    2016-01-01

    The development and implementation of research-inspired, discovery-based experiences into science laboratory curricula is a proven strategy for increasing student engagement and ownership of experiments. In the novel laboratory module described herein, students learn to express, purify, and characterize a carbohydrate-active enzyme using modern…

  10. The Zombie Instability: Using Numerical Simulation to Design a Laboratory Experiment

    NASA Astrophysics Data System (ADS)

    Wang, Meng; Pei, Suyang; Jiang, Chung-Hsiang; Hassanzadeh, Pedram; Marcus, Philip

    2014-11-01

    A new type of finite amplitude-instability has been found in numerical simulations of stratified, rotating, shear flows. The instability occurs via baroclinic critical layers that create linearly unstable vortex layers, which roll-up into vortices. Under the right conditions, those vortices can form a new generation of vortices, resulting in ``vortex self-replication'' that fills the fluid with vortices. Creating this instability in a laboratory would provide further evidence for the existence of the instability, which we first found in numerical simulations of protoplanetary disks. To design a laboratory experiment we need to know how the flow parameters-- shear, rotation and stratification, etc. affect the instability. To build an experiment economically, we also need to know how the finite-amplitude trigger of the instability scales with viscosity and the size of the domain. In this talk, we summarize our findings. We present a map, in terms of the experimentally controllable parameters, that shows where the instability occurs and whether the instability creates a few isolated transient vortices, a few long-lived vortices, or long-lived, self-replicating vortices that fill the entire flow.

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

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  12. Strain localization and fabric development in polycrystalline anorthite + melt by water diffusion in an axial deformation experiment

    NASA Astrophysics Data System (ADS)

    Fukuda, Jun-ichi; Muto, Jun; Nagahama, Hiroyuki

    2018-01-01

    We performed two axial deformation experiments on synthetic polycrystalline anorthite samples with a grain size of 3 μm and 5 vol% Si-Al-rich glass at 900 °C, a confining pressure of 1.0 GPa, and a strain rate of 10-4.8 s-1. One sample was deformed as-is (dry); in the other sample, two half-cut samples (two cores) with 0.15 wt% water at the boundary were put together in the apparatus. The mechanical data for both samples were essentially identical with a yield strength of 700 MPa and strain weakening of 500 MPa by 20% strain. The dry sample appears to have been deformed by distributed fracturing. Meanwhile, the water-added sample shows plastic strain localization in addition to fracturing and reaction products composed of zoisite grains and SiO2 materials along the boundary between the two sample cores. Infrared spectra of the water-added sample showed dominant water bands of zoisite. The maximum water content was 1500 wt ppm H2O at the two-core boundary, which is the same as the added amount. The water contents gradually decreased from the boundaries to the sample interior, and the gradient fitted well with the solution of the one-dimensional diffusion equation. The determined diffusion coefficient was 7.4 × 10-13 m2/s, which agrees with previous data for the grain boundary diffusion of water. The anorthite grains in the water-added sample showed no crystallographic preferred orientation. Textural observations and water diffusion indicate that water promotes the plastic deformation of polycrystalline anorthite by grain-size-sensitive creep as well as simultaneous reactions. We calculated the strain rate evolution controlled by water diffusion in feldspar aggregates surrounded by a water source. We assumed water diffusion in a dry rock mass with variable sizes. Diffused water weakens a rock mass with time under compressive stress. The calculated strain rate decreased from 10-10 to 10-15 s-1 with an increase in the rock mass size to which water is supplied from

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  14. Liquid-Liquid Extraction of Insecticides from Juice: An Analytical Chemistry Laboratory Experiment

    ERIC Educational Resources Information Center

    Radford, Samantha A.; Hunter, Ronald E., Jr.; Barr, Dana Boyd; Ryan, P. Barry

    2013-01-01

    A laboratory experiment was developed to target analytical chemistry students and to teach them about insecticides in food, sample extraction, and cleanup. Micro concentrations (sub-microgram/mL levels) of 12 insecticides spiked into apple juice samples are extracted using liquid-liquid extraction and cleaned up using either a primary-secondary…

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

    ERIC Educational Resources Information Center

    Tsionsky, Vladimir

    2007-01-01

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

  16. Local and transient nanoscale strain mapping during in situ deformation

    DOE PAGES

    Gammer, C.; Kacher, J.; Czarnik, C.; ...

    2016-08-26

    The mobility of defects such as dislocations controls the mechanical properties of metals. This mobility is determined both by the characteristics of the defect and the material, as well as the local stress and strain applied to the defect. Therefore, the knowledge of the stress and strain during deformation at the scale of defects is important for understanding fundamental deformation mechanisms. In this paper, we demonstrate a method of measuring local stresses and strains during continuous in situ deformation with a resolution of a few nanometers using nanodiffraction strain mapping. Finally, our results demonstrate how large multidimensional data sets capturedmore » with high speed electron detectors can be analyzed in multiple ways after an in situ TEM experiment, opening the door for true multimodal analysis from a single electron scattering experiment.« less

  17. Toward the development of intrafraction tumor deformation tracking using a dynamic multi-leaf collimator

    PubMed Central

    Ge, Yuanyuan; O’Brien, Ricky T.; Shieh, Chun-Chien; Booth, Jeremy T.; Keall, Paul J.

    2014-01-01

    Purpose: Intrafraction deformation limits targeting accuracy in radiotherapy. Studies show tumor deformation of over 10 mm for both single tumor deformation and system deformation (due to differential motion between primary tumors and involved lymph nodes). Such deformation cannot be adapted to with current radiotherapy methods. The objective of this study was to develop and experimentally investigate the ability of a dynamic multi-leaf collimator (DMLC) tracking system to account for tumor deformation. Methods: To compensate for tumor deformation, the DMLC tracking strategy is to warp the planned beam aperture directly to conform to the new tumor shape based on real time tumor deformation input. Two deformable phantoms that correspond to a single tumor and a tumor system were developed. The planar deformations derived from the phantom images in beam's eye view were used to guide the aperture warping. An in-house deformable image registration software was developed to automatically trigger the registration once new target image was acquired and send the computed deformation to the DMLC tracking software. Because the registration speed is not fast enough to implement the experiment in real-time manner, the phantom deformation only proceeded to the next position until registration of the current deformation position was completed. The deformation tracking accuracy was evaluated by a geometric target coverage metric defined as the sum of the area incorrectly outside and inside the ideal aperture. The individual contributions from the deformable registration algorithm and the finite leaf width to the tracking uncertainty were analyzed. Clinical proof-of-principle experiment of deformation tracking using previously acquired MR images of a lung cancer patient was implemented to represent the MRI-Linac environment. Intensity-modulated radiation therapy (IMRT) treatment delivered with enabled deformation tracking was simulated and demonstrated. Results: The first

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  19. Crush Testing at Oak Ridge National Laboratory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Feldman, Matthew R

    2011-01-01

    The dynamic crush test is required in the certification testing of some small Type B transportation packages. International Atomic Energy Agency regulations state that the test article must be 'subjected to a dynamic crush test by positioning the specimen on the target so as to suffer maximum damage.' Oak Ridge National Laboratory (ORNL) Transportation Technologies Group performs testing of Type B transportation packages, including the crush test, at the National Transportation Research Center in Knoxville, Tennessee (United States). This paper documents ORNL's experiences performing crush tests on several different Type B packages. ORNL has crush tested five different drum-type packagemore » designs, continuing its 60 year history of RAM package testing. A total of 26 crush tests have been performed in a wide variety of package orientations and crush plate CG alignments. In all cases, the deformation of the outer drum created by the crush test was significantly greater than the deformation damage caused by the 9 m drop test. The crush test is a highly effective means for testing structural soundness of smaller nondense Type B shipping package designs. Further regulatory guidance could alleviate the need to perform the crush test in a wide range of orientations and crush plate CG alignments.« less

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  1. Black hole acoustics in the minimal geometric deformation of a de Laval nozzle

    NASA Astrophysics Data System (ADS)

    da Rocha, Roldão

    2017-05-01

    The correspondence between sound waves, in a de Laval propelling nozzle, and quasinormal modes emitted by brane-world black holes deformed by a 5D bulk Weyl fluid are here explored and scrutinized. The analysis of sound waves patterns in a de Laval nozzle in the laboratory, reciprocally, is here shown to provide relevant data about the 5D bulk Weyl fluid and its on-brane projection, comprised by the minimal geometrically deformed compact stellar distribution on the brane. Acoustic perturbations of the gas fluid flow in the de Laval nozzle are proved to coincide with the quasinormal modes of black holes solutions deformed by the 5D Weyl fluid, in the geometric deformation procedure. Hence, in a phenomenological Eötvös-Friedmann fluid brane-world model, the realistic shape of a de Laval nozzle is derived and its consequences studied.

  2. Strength and Deformation Behaviour of Cap Rocks Above the CO2SINK-Reservoir

    NASA Astrophysics Data System (ADS)

    Mutschler, T.; Triantafyllidis, T.; Balthasar, K.; Norden, B.

    2009-04-01

    The cap-rock of the CO2SINK storage site close to Ketzin consists of clay rich rocks which are typical for cap rock formations above CO2 storage reservoirs. The strength and deformation behaviour of such claystone samples are therefore of fundamental importance for the characterization of secure geological storage of CO2. The elastic and anelastic deformation behaviour limits the maximum injection pressure during CO2-injection and is part of the security measures for the long term storage of CO2. The laboratory experiments where performed on samples gathered from the injection well of the Ketzin pilot test site in Germany and are compared with the elastic and anelastic behaviour of samples from the same Keuper formation in a near-surface outcrop in the Southwest of Germany showing a similar lithology. The samples from the outcrop allowed drilling of samples with a standard size of 100 mm diameter and 200 mm height as well as large samples with a diameter of 550 mm and a height of 1200 mm. The investigations have a special emphasis on the viscous behaviour of the clay stones and its scaling behaviour. A special triaxial testing procedure is applied both on standard and large size samples allowing the determination of the strength, stiffness and viscosity behaviour of the rock in one experimental run. Multi-stage technique (stepwise variation of the confining pressure) gives the strength behaviour of each single sample while applying a constant deformation rate. Stepwise varied deformation rates on the other hand lead to steps in the stress-strain-curve from which the viscosity index is determined. The viscosity index is directly used in the Norton's constitutive relations for viscoplastic simulations. The combination of tests allows for the determination of a broad range of elastic and anelastic properties. The comparison of results - both for elastic and anelastic behaviour - from standard and large samples shows that for the examined rocks a scale effect is

  3. Evaluation of Surface Runoff Generation Processes Using a Rainfall Simulator: A Small Scale Laboratory Experiment

    NASA Astrophysics Data System (ADS)

    Danáčová, Michaela; Valent, Peter; Výleta, Roman

    2017-12-01

    Nowadays, rainfall simulators are being used by many researchers in field or laboratory experiments. The main objective of most of these experiments is to better understand the underlying runoff generation processes, and to use the results in the process of calibration and validation of hydrological models. Many research groups have assembled their own rainfall simulators, which comply with their understanding of rainfall processes, and the requirements of their experiments. Most often, the existing rainfall simulators differ mainly in the size of the irrigated area, and the way they generate rain drops. They can be characterized by the accuracy, with which they produce a rainfall of a given intensity, the size of the irrigated area, and the rain drop generating mechanism. Rainfall simulation experiments can provide valuable information about the genesis of surface runoff, infiltration of water into soil and rainfall erodibility. Apart from the impact of physical properties of soil, its moisture and compaction on the generation of surface runoff and the amount of eroded particles, some studies also investigate the impact of vegetation cover of the whole area of interest. In this study, the rainfall simulator was used to simulate the impact of the slope gradient of the irrigated area on the amount of generated runoff and sediment yield. In order to eliminate the impact of external factors and to improve the reproducibility of the initial conditions, the experiments were conducted in laboratory conditions. The laboratory experiments were carried out using a commercial rainfall simulator, which was connected to an external peristaltic pump. The pump maintained a constant and adjustable inflow of water, which enabled to overcome the maximum volume of simulated precipitation of 2.3 l, given by the construction of the rainfall simulator, while maintaining constant characteristics of the simulated precipitation. In this study a 12-minute rainfall with a constant intensity

  4. Deformable Mirrors Correct Optical Distortions

    NASA Technical Reports Server (NTRS)

    2010-01-01

    By combining the high sensitivity of space telescopes with revolutionary imaging technologies consisting primarily of adaptive optics, the Terrestrial Planet Finder is slated to have imaging power 100 times greater than the Hubble Space Telescope. To this end, Boston Micromachines Corporation, of Cambridge, Massachusetts, received Small Business Innovation Research (SBIR) contracts from the Jet Propulsion Laboratory for space-based adaptive optical technology. The work resulted in a microelectromechanical systems (MEMS) deformable mirror (DM) called the Kilo-DM. The company now offers a full line of MEMS DMs, which are being used in observatories across the world, in laser communication, and microscopy.

  5. 2017 GTO Project review Laboratory Evaluation of EGS Shear Stimulation.

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bauer, Stephen J.

    The objectives and purpose of this research has been to produce laboratory-based experimental and numerical analyses to provide a physics-based understanding of shear stimulation phenomena (hydroshearing) and its evolution during stimulation. Water was flowed along fractures in hot and stressed fractured rock, to promote slip. The controlled laboratory experiments provide a high resolution/high quality data resource for evaluation of analysis methods developed by DOE to assess EGS “behavior” during this stimulation process. Segments of the experimental program will provide data sets for model input parameters, i.e., material properties, and other segments of the experimental program will represent small scale physicalmore » models of an EGS system, which may be modeled. The coupled lab/analysis project has been a study of the response of a fracture in hot, water-saturated fractured rock to shear stress experiencing fluid flow. Under this condition, the fracture experiences a combination of potential pore pressure changes and fracture surface cooling, resulting in slip along the fracture. The laboratory work provides a means to assess the role of “hydroshearing” on permeability enhancement in reservoir stimulation. Using the laboratory experiments and results to define boundary and input/output conditions of pore pressure, thermal stress, fracture shear deformation and fluid flow, and models were developed and simulations completed by the University of Oklahoma team. The analysis methods are ones used on field scale problems. The sophisticated numerical models developed contain parameters present in the field. The analysis results provide insight into the role of fracture slip on permeability enhancement-“hydroshear” is to be obtained. The work will provide valuable input data to evaluate stimulation models, thus helping design effective EGS.« less

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

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

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

    ERIC Educational Resources Information Center

    Schepmann, Hala G.; Mynderse, Michelle

    2010-01-01

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

  8. Analyzing Exonuclease-Induced Hyperchromicity by Uv Spectroscopy: An Undergraduate Biochemistry Laboratory Experiment

    ERIC Educational Resources Information Center

    Ackerman, Megan M.; Ricciardi, Christopher; Weiss, David; Chant, Alan; Kraemer-Chant, Christina M.

    2016-01-01

    An undergraduate biochemistry laboratory experiment is described that utilizes free online bioinformatics tools along with readily available exonucleases to study the effects of base stacking and hydrogen bonding on the UV absorbance of DNA samples. UV absorbance of double-stranded DNA at the ?[subscript max] is decreased when the DNA bases are…

  9. Creep model of unsaturated sliding zone soils and long-term deformation analysis of landslides

    NASA Astrophysics Data System (ADS)

    Zou, Liangchao; Wang, Shimei; Zhang, Yeming

    2015-04-01

    Sliding zone soil is a special soil layer formed in the development of a landslide. Its creep behavior plays a significant role in long-term deformation of landslides. Due to rainfall infiltration and reservoir water level fluctuation, the soils in the slide zone are often in unsaturated state. Therefore, the investigation of creep behaviors of the unsaturated sliding zone soils is of great importance for understanding the mechanism of the long-term deformation of a landslide in reservoir areas. In this study, the full-process creep curves of the unsaturated soils in the sliding zone in different net confining pressure, matric suctions and stress levels were obtained from a large number of laboratory triaxial creep tests. A nonlinear creep model for unsaturated soils and its three-dimensional form was then deduced based on the component model theory and unsaturated soil mechanics. This creep model was validated with laboratory creep data. The results show that this creep model can effectively and accurately describe the nonlinear creep behaviors of the unsaturated sliding zone soils. In order to apply this creep model to predict the long-term deformation process of landslides, a numerical model for simulating the coupled seepage and creep deformation of unsaturated sliding zone soils was developed based on this creep model through the finite element method (FEM). By using this numerical model, we simulated the deformation process of the Shuping landslide located in the Three Gorges reservoir area, under the cycling reservoir water level fluctuation during one year. The simulation results of creep displacement were then compared with the field deformation monitoring data, showing a good agreement in trend. The results show that the creeping deformations of landslides have strong connections with the changes of reservoir water level. The creep model of unsaturated sliding zone soils and the findings obtained by numerical simulations in this study are conducive to

  10. Observations of nonlinear and nonuniform kink dynamics in a laboratory flux rope

    NASA Astrophysics Data System (ADS)

    Sears, J.; Intrator, T.; Feng, Y.; Swan, H.; Gao, K.; Chapdelaine, L.

    2013-12-01

    A plasma column with axial magnetic field and current has helically twisted field lines. When current density in the column exceeds the kink instability threshold this magnetic configuration becomes unstable. Flux ropes in the solar wind and some solar prominences exhibit this topology, with their dynamics strongly and nonlinearly coupled to the ratio of axial current to magnetic field. The current-driven kink mode is ubiquitous in laboratory plasmas and well suited to laboratory study. In the Reconnection Scaling Experiment (RSX), nonlinear stability properties beyond the simple perturbative kink model are observed and readily diagnosed. We use a plasma gun to generate a single plasma column 0.50 m in length, in which we then drive an axial plasma current at the limit of marginal kink stability. With plasma current maintained at this threshold, we observe a deformation to a new dynamic equilibrium with finite gyration amplitude, where the currents and magnetic fields that support the force balance have surprising axial structure. Three dimensional measurements of magnetic field, plasma density, plasma potential, and ion flow velocity in the deformed plasma column show variation in the axial direction of the instability parameter and in the terms of the momentum equation. Likewise the pitch of the kink is measured to be nonuniform over the column length. In addition there is a return current antiparallel to the driven plasma current at distances up to 0.30 m from the gun that also modifies the force balance. These axial inhomogeneities, which are not considered in the model of an ideal kink, may be the terms that allow the deformed equilibrium of the RSX plasma to exist. Supported by DOE Office of Fusion Energy Sciences under LANS contract DE-AC52-06NA25369, NASA Geospace NNHIOA044I, Basic. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  11. Transient deformation of a droplet near a microfluidic constriction: A quantitative analysis

    NASA Astrophysics Data System (ADS)

    Trégouët, Corentin; Salez, Thomas; Monteux, Cécile; Reyssat, Mathilde

    2018-05-01

    We report on experiments that consist of deforming a collection of monodisperse droplets produced by a microfluidic chip through a flow-focusing device. We show that a proper numerical modeling of the flow is necessary to access the stress applied by the latter on the droplet along its trajectory through the chip. This crucial step enables the full integration of the differential equation governing the dynamical deformation, and consequently the robust measurement of the interfacial tension by fitting the experiments with the calculated deformation. Our study thus demonstrates the feasibility of quantitative in situ rheology in microfluidic flows involving, e.g., droplets, capsules, or cells.

  12. Experiments with an ESOL Reading Laboratory.

    ERIC Educational Resources Information Center

    Ahrens, Patricia

    The reading laboratory has been developed to supplement intensive reading work for adult foreign students developing English-as-a-second-language skills at the American Language Institute. The laboratory is designed to suggest to students that there is a variety of reading tasks and a variety of reading strategies related to the tasks, to offer…

  13. Natural and laboratory compaction bands in porous carbonates: a three-dimensional characterization using synchrotron X-ray computed microtomography

    NASA Astrophysics Data System (ADS)

    Cilona, A.; Arzilli, F.; Mancini, L.; Emanuele, T.

    2014-12-01

    Porous carbonates form important reservoirs for water and hydrocarbons. The fluid flow properties of carbonate reservoirs may be affected by post-depositional processes (e.g., mechanical and chemical), which need to be quantified. Field-based studies described bed-parallel compaction bands (CBs) within carbonates with a wide range of porosities. These burial-related structures accommodate volumetric strain by grain rotation, translation, pore collapse and pressure solution. Recently, the same structures have been reproduced for the first time in the laboratory by performing triaxial compaction experiments on porous grainstones. These laboratory studies characterized and compared the microstructures of natural and laboratory CBs, but no analysis of pore connectivity has been performed. In this paper, we use an innovative approach to characterize the pore networks (e.g. porosity, connectivity) of natural and laboratory CBs and compare them with the host rock one. We collected the data using the synchrotron X-ray computed microtomography technique at the SYRMEP beamline of the Elettra-Sincrotrone Trieste Laboratory (Italy). Quantitative analyses of the samples were performed with the Pore3D software library. The porosity was calculated from segmented 3D images of pristine and deformed carbonates. A process of skeletonization was then applied to quantify the number of connected pores within the rock volume. The analysis of the skeleton allowed us to highlight the differences between natural and laboratory CBs, and to investigate how pore connectivity evolves as a function of different deformation pathways. Both pore volume and connectivity are reduced within the CBs respect to the pristine rock and the natural CB has a lower porosity with respect to the laboratory one. The grain contacts in the natural CB are welded, whereas in the laboratory one they have more irregular shapes and grain crushing is the predominant process.

  14. Deformable image registration for tissues with large displacements

    PubMed Central

    Huang, Xishi; Ren, Jing; Green, Mark

    2017-01-01

    Abstract. Image registration for internal organs and soft tissues is considered extremely challenging due to organ shifts and tissue deformation caused by patients’ movements such as respiration and repositioning. In our previous work, we proposed a fast registration method for deformable tissues with small rotations. We extend our method to deformable registration of soft tissues with large displacements. We analyzed the deformation field of the liver by decomposing the deformation into shift, rotation, and pure deformation components and concluded that in many clinical cases, the liver deformation contains large rotations and small deformations. This analysis justified the use of linear elastic theory in our image registration method. We also proposed a region-based neuro-fuzzy transformation model to seamlessly stitch together local affine and local rigid models in different regions. We have performed the experiments on a liver MRI image set and showed the effectiveness of the proposed registration method. We have also compared the performance of the proposed method with the previous method on tissues with large rotations and showed that the proposed method outperformed the previous method when dealing with the combination of pure deformation and large rotations. Validation results show that we can achieve a target registration error of 1.87±0.87  mm and an average centerline distance error of 1.28±0.78  mm. The proposed technique has the potential to significantly improve registration capabilities and the quality of intraoperative image guidance. To the best of our knowledge, this is the first time that the complex displacement of the liver is explicitly separated into local pure deformation and rigid motion. PMID:28149924

  15. 40Ar* loss in experimentally deformed muscovite and biotite with implications for 40Ar/39Ar geochronology of naturally deformed rocks

    USGS Publications Warehouse

    Cosca, M.; Stunitz, H.; Bourgeix, A.-L.; Lee, J.P.

    2011-01-01

    The effects of deformation on radiogenic argon (40Ar*) retentivity in mica are described from high pressure experiments performed on rock samples of peraluminous granite containing euhedral muscovite and biotite. Cylindrical cores, ???15mm in length and 6.25mm in diameter, were drilled from granite collected from the South Armorican Massif in northwestern France, loaded into gold capsules, and weld-sealed in the presence of excess water. The samples were deformed at a pressure of 10kb and a temperature of 600??C over a period 29 of hours within a solid medium assembly in a Griggs-type triaxial hydraulic deformation apparatus. Overall shortening in the experiments was approximately 10%. Transmitted light and secondary and backscattered electron imaging of the deformed granite samples reveals evidence of induced defects and for significant physical grain size reduction by kinking, cracking, and grain segmentation of the micas.Infrared (IR) laser (CO2) heating of individual 1.5-2.5mm diameter grains of muscovite and biotite separated from the undeformed granite yield well-defined 40Ar/39Ar plateau ages of 311??2Ma (2??). Identical experiments on single grains separated from the experimentally deformed granite yield results indicating 40Ar* loss of 0-35% in muscovite and 2-3% 40Ar* loss in biotite. Intragrain in situ ultraviolet (UV) laser ablation 40Ar/39Ar ages (??4-10%, 1??) of deformed muscovites range from 309??13 to 264??7Ma, consistent with 0-16% 40Ar* loss relative to the undeformed muscovite. The in situ UV laser ablation 40Ar/39Ar ages of deformed biotite vary from 301 to 217Ma, consistent with up to 32% 40Ar* loss. No spatial correlation is observed between in situ 40Ar/39Ar age and position within individual grains. Using available argon diffusion data for muscovite the observed 40Ar* loss in the experimentally treated muscovite can be utilized to predict average 40Ar* diffusion dimensions. Maximum 40Ar/39Ar ages obtained by UV laser ablation overlap those

  16. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  18. Error in the determination of the deformed shape of prismatic beams using the double integration of curvature

    NASA Astrophysics Data System (ADS)

    Sigurdardottir, Dorotea H.; Stearns, Jett; Glisic, Branko

    2017-07-01

    The deformed shape is a consequence of loading the structure and it is defined by the shape of the centroid line of the beam after deformation. The deformed shape is a universal parameter of beam-like structures. It is correlated with the curvature of the cross-section; therefore, any unusual behavior that affects the curvature is reflected through the deformed shape. Excessive deformations cause user discomfort, damage to adjacent structural members, and may ultimately lead to issues in structural safety. However, direct long-term monitoring of the deformed shape in real-life settings is challenging, and an alternative is indirect determination of the deformed shape based on curvature monitoring. The challenge of the latter is an accurate evaluation of error in the deformed shape determination, which is directly correlated with the number of sensors needed to achieve the desired accuracy. The aim of this paper is to study the deformed shape evaluated by numerical double integration of the monitored curvature distribution along the beam, and create a method to predict the associated errors and suggest the number of sensors needed to achieve the desired accuracy. The error due to the accuracy in the curvature measurement is evaluated within the scope of this work. Additionally, the error due to the numerical integration is evaluated. This error depends on the load case (i.e., the shape of the curvature diagram), the magnitude of curvature, and the density of the sensor network. The method is tested on a laboratory specimen and a real structure. In a laboratory setting, the double integration is in excellent agreement with the beam theory solution which was within the predicted error limits of the numerical integration. Consistent results are also achieved on a real structure—Streicker Bridge on Princeton University campus.

  19. The LUNA experiment at Gran Sasso Laboratory: Studying stars by going underground

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guglielmetti, Alessandra

    2015-10-15

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

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

    ERIC Educational Resources Information Center

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

    2008-01-01

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

  1. Viscoelastic deformation of lipid bilayer vesicles.

    PubMed

    Wu, Shao-Hua; Sankhagowit, Shalene; Biswas, Roshni; Wu, Shuyang; Povinelli, Michelle L; Malmstadt, Noah

    2015-10-07

    Lipid bilayers form the boundaries of the cell and its organelles. Many physiological processes, such as cell movement and division, involve bending and folding of the bilayer at high curvatures. Currently, bending of the bilayer is treated as an elastic deformation, such that its stress-strain response is independent of the rate at which bending strain is applied. We present here the first direct measurement of viscoelastic response in a lipid bilayer vesicle. We used a dual-beam optical trap (DBOT) to stretch 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) giant unilamellar vesicles (GUVs). Upon application of a step optical force, the vesicle membrane deforms in two regimes: a fast, instantaneous area increase, followed by a much slower stretching to an eventual plateau deformation. From measurements of dozens of GUVs, the average time constant of the slower stretching response was 0.225 ± 0.033 s (standard deviation, SD). Increasing the fluid viscosity did not affect the observed time constant. We performed a set of experiments to rule out heating by laser absorption as a cause of the transient behavior. Thus, we demonstrate here that the bending deformation of lipid bilayer membranes should be treated as viscoelastic.

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

    NASA Astrophysics Data System (ADS)

    Ji, H.; Bhattacharjee, A.; Prager, S.; Daughton, W. S.; Bale, S. D.; Carter, T. A.; Crocker, N.; Drake, J. F.; Egedal, J.; Sarff, J.; Wallace, J.; Belova, E.; Ellis, R.; Fox, W. R., II; Heitzenroeder, P.; Kalish, M.; Jara-Almonte, J.; Myers, C. E.; Que, W.; Ren, Y.; Titus, P.; Yamada, M.; Yoo, J.

    2014-12-01

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

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

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  4. Emulation-Based Virtual Laboratories: A Low-Cost Alternative to Physical Experiments in Control Engineering Education

    ERIC Educational Resources Information Center

    Goodwin, G. C.; Medioli, A. M.; Sher, W.; Vlacic, L. B.; Welsh, J. S.

    2011-01-01

    This paper argues the case for emulation-based virtual laboratories in control engineering education. It demonstrates that such emulation experiments can give students an industrially relevant educational experience at relatively low cost. The paper also describes a particular emulation-based system that has been developed with the aim of giving…

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

    ERIC Educational Resources Information Center

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

    2008-01-01

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

  6. Quantitative Analysis Of Acoustic Emission From Rock Fracture Experiments

    NASA Astrophysics Data System (ADS)

    Goodfellow, Sebastian David

    This thesis aims to advance the methods of quantitative acoustic emission (AE) analysis by calibrating sensors, characterizing sources, and applying the results to solve engi- neering problems. In the first part of this thesis, we built a calibration apparatus and successfully calibrated two commercial AE sensors. The ErgoTech sensor was found to have broadband velocity sensitivity and the Panametrics V103 was sensitive to surface normal displacement. These calibration results were applied to two AE data sets from rock fracture experiments in order to characterize the sources of AE events. The first data set was from an in situ rock fracture experiment conducted at the Underground Research Laboratory (URL). The Mine-By experiment was a large scale excavation response test where both AE (10 kHz - 1 MHz) and microseismicity (MS) (1 Hz - 10 kHz) were monitored. Using the calibration information, magnitude, stress drop, dimension and energy were successfully estimated for 21 AE events recorded in the tensile region of the tunnel wall. Magnitudes were in the range -7.5 < Mw < -6.8, which is consistent with other laboratory AE results, and stress drops were within the range commonly observed for induced seismicity in the field (0.1 - 10 MPa). The second data set was AE collected during a true-triaxial deformation experiment, where the objectives were to characterize laboratory AE sources and identify issues related to moving the analysis from ideal in situ conditions to more complex laboratory conditions in terms of the ability to conduct quantitative AE analysis. We found AE magnitudes in the range -7.8 < Mw < -6.7 and as with the in situ data, stress release was within the expected range of 0.1 - 10 MPa. We identified four major challenges to quantitative analysis in the laboratory, which in- hibited our ability to study parameter scaling (M0 ∝ fc -3 scaling). These challenges were 0c (1) limited knowledge of attenuation which we proved was continuously evolving, (2

  7. Experimental Deformation of Dehydrating Antigorite: Challenging Models of Dehydration Embrittlement

    NASA Astrophysics Data System (ADS)

    Hirth, Greg; Chernak, Linda

    2010-05-01

    To test the hypothesis that intermediate depth earthquakes in subduction zones are caused by the dehydration of hydrous phases, we conducted temperature-ramping experiments on antigorite serpentinite. Cold-pressed powdered samples of antigorite were deformed to a high differential stress at 400°C and 1.0 GPa, within the antigorite stability field, where we have shown that deformation localizes. Temperature was then increased at different rates, 1800°C/hr and 180°C/hr, to cross the reaction boundary while the sample continued to deform; samples were deformed at strain rates of 10-4 s-1, 10-5 s-1 and 10-6 s-1. Two additional experiments were conducted in a similar manner at 300°C, 1.5 GPa and 10-5 s-1 but samples remained 'statically' at high stress during the temperature increase. Our results show that although the decrease in stress during temperature ramping is large, stress relaxes stably, even after dehydration. We find that the slopes of the unloading curves are approximately the same for constant values of the ratio (strain rate/ramp rate) and that the unloading slope is greater for higher values of this ratio. In addition, we find that the unloading curves with the greatest slopes are similar to the apparatus compliance, suggesting that we are generating 'slow earthquakes' in our experiments over the course 5 to 10s of minutes. A strain rate stepping experiment indicates that antigorite has velocity strengthening behavior at 700°C and 1.5 GPa suggesting that as soon as an instability develops in the antigorite, the material strengthens sufficiently to not go unstable. Our results thus suggest that antigorite dehydration does not result in 'dehydration embrittlement' but that it may promote slow earthquakes. We have also conducted a preliminary experiment to study the role of effective pressure on deformation behavior after dehydration. A cold-pressed powdered sample of antigorite with a small core of coarse-grained olivine at one end was deformed at 700

  8. Transitioning from Expository Laboratory Experiments to Course-Based Undergraduate Research in General Chemistry

    ERIC Educational Resources Information Center

    Clark, Ted M.; Ricciardo, Rebecca; Weaver, Tyler

    2016-01-01

    General chemistry courses predominantly use expository experiments that shape student expectations of what a laboratory activity entails. Shifting within a semester to course-based undergraduate research activities that include greater decision-making, collaborative work, and "messy" real-world data necessitates a change in student…

  9. Whitson looks at the ADVASC Soybean plant growth experiment in the U.S. Laboratory

    NASA Image and Video Library

    2002-07-18

    ISS005-E-08001 (18 July 2002) --- Astronaut Peggy A. Whitson, Expedition Five flight engineer, works with the Advanced Astroculture soybean plant growth experiment in the Destiny laboratory on the International Space Station (ISS).

  10. Residual stresses and plastic deformation in GTA-welded steel

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Brand, P.C.; Keijser, T.H. de; Ouden, G. den

    1993-03-01

    Residual stresses and plastic deformation in single pass GTA welded low-carbon steel were studied by means of x-ray diffraction in combination with optical microscopy and hardness measurements. The residual stresses and the amount of plastic deformation (microstrain) were obtained from x-ray diffraction line positions and line broading. Since the plates were polished before welding, it was possible to observe in the optical microscope two types of Lueders bands. During heating curved Lueders bands and during cooling straight Lueders bands perpendicular to the weld are formed. The curved Lueders bands extend over a larger distance from the weld than the straightmore » Lueders bands. The amount of plastic deformation as obtained from the x-ray diffraction analysis is in agreement with these observations. An explanation is offered for the stresses measured in combination with plastic deformations observed. It is concluded that in the present experiments plastic deformation is the main cause of the residual stresses.« less

  11. Tension-dependent structural deformation alters single-molecule transition kinetics.

    PubMed

    Sudhanshu, B; Mihardja, S; Koslover, E F; Mehraeen, S; Bustamante, C; Spakowitz, A J

    2011-02-01

    We analyze the response of a single nucleosome to tension, which serves as a prototypical biophysical measurement where tension-dependent deformation alters transition kinetics. We develop a statistical-mechanics model of a nucleosome as a wormlike chain bound to a spool, incorporating fluctuations in the number of bases bound, the spool orientation, and the conformations of the unbound polymer segments. With the resulting free-energy surface, we perform dynamic simulations that permit a direct comparison with experiments. This simple approach demonstrates that the experimentally observed structural states at nonzero tension are a consequence of the tension and that these tension-induced states cease to exist at zero tension. The transitions between states exhibit substantial deformation of the unbound polymer segments. The associated deformation energy increases with tension; thus, the application of tension alters the kinetics due to tension-induced deformation of the transition states. This mechanism would arise in any system where the tether molecule is deformed in the transition state under the influence of tension.

  12. Toward the development of intrafraction tumor deformation tracking using a dynamic multi-leaf collimator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ge, Yuanyuan; O’Brien, Ricky T.; Shieh, Chun-Chien

    Purpose: Intrafraction deformation limits targeting accuracy in radiotherapy. Studies show tumor deformation of over 10 mm for both single tumor deformation and system deformation (due to differential motion between primary tumors and involved lymph nodes). Such deformation cannot be adapted to with current radiotherapy methods. The objective of this study was to develop and experimentally investigate the ability of a dynamic multi-leaf collimator (DMLC) tracking system to account for tumor deformation. Methods: To compensate for tumor deformation, the DMLC tracking strategy is to warp the planned beam aperture directly to conform to the new tumor shape based on real timemore » tumor deformation input. Two deformable phantoms that correspond to a single tumor and a tumor system were developed. The planar deformations derived from the phantom images in beam's eye view were used to guide the aperture warping. An in-house deformable image registration software was developed to automatically trigger the registration once new target image was acquired and send the computed deformation to the DMLC tracking software. Because the registration speed is not fast enough to implement the experiment in real-time manner, the phantom deformation only proceeded to the next position until registration of the current deformation position was completed. The deformation tracking accuracy was evaluated by a geometric target coverage metric defined as the sum of the area incorrectly outside and inside the ideal aperture. The individual contributions from the deformable registration algorithm and the finite leaf width to the tracking uncertainty were analyzed. Clinical proof-of-principle experiment of deformation tracking using previously acquired MR images of a lung cancer patient was implemented to represent the MRI-Linac environment. Intensity-modulated radiation therapy (IMRT) treatment delivered with enabled deformation tracking was simulated and demonstrated. Results: The first

  13. Beyond Brittle Deformation: Insights into Seismogenic Slip Processes from Natural and Experimental Faults

    NASA Astrophysics Data System (ADS)

    Holdsworth, R.; De Paola, N.; Bullock, R. J.; Collettini, C.; Viti, C.; Nielsen, S. B.

    2015-12-01

    Shear displacements in upper crustal faults are typically localized within cm- to m-thick high strain fault cores composed of interlayered tabular domains of cataclasite and gouge. Evidence from exhumed/exposed seismic faults shows that the great majority of co-seismic slip is taken up along narrow (<10 cm) ultracataclasite slip zones, containing thin (<100μm) principal slip zones (PSZ) bounded by sharp, polished and striated principal slip surfaces (PSS). Even in unconsolidated materials deformed near to the surface, seismogenic slip is observed to localize within discrete, narrow PSZs. Theoretical studies suggest that in all but the shallowest settings, the natural PSZs may be sufficiently thin to generate localised frictional heating that potentially promotes thermally-activated dynamic weakening mechanisms. We can recreate these processes in the laboratory using displacement-controlled friction experiments performed in a rotary shear apparatus on fault gouges of known composition deformed at seismic slip rates (v > 1ms-1) and normal stresses of up to 20 MPa. A sequential sampling approach is used in which slip is arrested at different stages of the observed friction evolution (e.g. post-compaction, peak friction, steady state after weakening). This allows the evolution of gouge microstructures and deformation mechanisms in the experimental samples to be: a) related to the evolving temperature regimes in the PSZ and changing mechanical behavior; and b) compared to natural PSZ/PSSs. Using this approach we have investigated the behavior and deformation mechanisms of gouges made of common, rock-forming minerals (calcite, clays, olivine, quartz) both in pure form and, in some cases, as mixed compositions deformed under a range of experimental conditions. We have studied the effects of varying confining pressure, fluid content (room humidity vs water saturated) and composition (de-ionized water vs brine) and slip rate (e.g. seismic vs. sub-seismic). Our findings

  14. Solid deuterated water in space: detection constraints from laboratory experiments

    NASA Astrophysics Data System (ADS)

    Urso, R. G.; Palumbo, M. E.; Baratta, G. A.; Scirè, C.; Strazzulla, G.

    2018-06-01

    The comparison between astronomical spectra and laboratory experiments is fundamental to spread light on the structure and composition of ices found in interstellar dense molecular clouds and in Solar System bodies. Water is among the most abundant solid-phase species observed in these environments, and several attempts have been made to investigate the presence of its solid-phase isotopologues. In particular, the detection of the O-D stretching mode band at 4.1 μm due to both D2O and HDO within icy grain mantles is still under debate, and no detection have been reported about the presence of these species within icy bodies in the Solar System yet. In the near future, an important contribution could derive from the data acquired in the O-D stretching mode spectral range by the sensitive instruments on board the James Webb Space Telescope. With this in mind, we performed several laboratory experiments to study the O-D stretching mode band in solid mixtures containing water and deuterated water deposited in the temperature range between 17 and 155 K, in order to simulate astrophysical relevant conditions. Furthermore, samples have been studied at various temperature and irradiated with energetic ions (200 keV H+) in order to study the effects induced by both thermal and energetic processing. Our results provide some constraints on the detection of the 4.1 μm band in astronomical environments.

  15. Identification of Skeletal Deformities in Far Eastern Catfish, Silurus asotus under Indoor Aquaculture Condition

    PubMed Central

    Yang, Won Seok; Gil, Hyun Woo; Yoo, Gwang Yeol; Park, In-Seok

    2015-01-01

    For the 2 years of farming, at the indoor circulating aquaculture system, four kinds of skeletal deformities were found among 60 Far Eastern catfish, Silurus asotus. Deformities saw jawbone’s luxation, abnormality of upper lip and malocclusion. Spinal deformity was most fatal deformities with low weight and small length. Jawbone’s luxation had 1 maxilla and 2 mandibles. Abnormality of upper lip had just lip was back over. Malocclusion’s left maxilla and right maxilla were not balanced. This experiment was any deformities in this species through the deformity can grasp how it affects. PMID:27004272

  16. Variety of Sedimentary Process and Distribution of Tsunami Deposits in Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Yamaguchi, N.; Sekiguchi, T.

    2017-12-01

    As an indicator of the history and magnitude of paleotsunami events, tsunami deposits have received considerable attention. To improve the identification and interpretation of paleotsunami deposits, an understanding of sedimentary process and distribution of tsunami deposits is crucial. Recent detailed surveys of onshore tsunami deposits including the 2004 Indian Ocean tsunami and the 2011 Tohoku-oki tsunami have revealed that terrestrial topography causes a variety of their features and distributions. Therefore, a better understanding of possible sedimentary process and distribution on such influential topographies is required. Flume experiments, in which sedimentary conditions can be easily controlled, can provide insights into the effects of terrestrial topography as well as tsunami magnitude on the feature of tsunami deposits. In this presentation, we report laboratory experiments that focused on terrestrial topography including a water body (e.g. coastal lake) on a coastal lowland and a cliff. In both cases, the results suggested relationship between the distribution of tsunami deposits and the hydraulic condition of the tsunami flow associated with the terrestrial topography. These experiments suggest that influential topography would enhance the variability in thickness of tsunami deposits, and thus, in reconstructions of paleotsunami events using sedimentary records, we should take into account such anomalous distribution of tsunami deposits. Further examination of the temporal sequence of sedimentary process in laboratory tsunamis may improve interpretation and estimation of paleotsunami events.

  17. 40Ar ∗ loss in experimentally deformed muscovite and biotite with implications for 40Ar/ 39Ar geochronology of naturally deformed rocks

    NASA Astrophysics Data System (ADS)

    Cosca, Michael; Stunitz, Holger; Bourgeix, Anne-Lise; Lee, John P.

    2011-12-01

    The effects of deformation on radiogenic argon ( 40Ar ∗) retentivity in mica are described from high pressure experiments performed on rock samples of peraluminous granite containing euhedral muscovite and biotite. Cylindrical cores, ˜15 mm in length and 6.25 mm in diameter, were drilled from granite collected from the South Armorican Massif in northwestern France, loaded into gold capsules, and weld-sealed in the presence of excess water. The samples were deformed at a pressure of 10 kb and a temperature of 600 °C over a period 29 of hours within a solid medium assembly in a Griggs-type triaxial hydraulic deformation apparatus. Overall shortening in the experiments was approximately 10%. Transmitted light and secondary and backscattered electron imaging of the deformed granite samples reveals evidence of induced defects and for significant physical grain size reduction by kinking, cracking, and grain segmentation of the micas. Infrared (IR) laser (CO 2) heating of individual 1.5-2.5 mm diameter grains of muscovite and biotite separated from the undeformed granite yield well-defined 40Ar/ 39Ar plateau ages of 311 ± 2 Ma (2σ). Identical experiments on single grains separated from the experimentally deformed granite yield results indicating 40Ar ∗ loss of 0-35% in muscovite and 2-3% 40Ar ∗ loss in biotite. Intragrain in situ ultraviolet (UV) laser ablation 40Ar/ 39Ar ages (±4-10%, 1σ) of deformed muscovites range from 309 ± 13 to 264 ± 7 Ma, consistent with 0-16% 40Ar ∗ loss relative to the undeformed muscovite. The in situ UV laser ablation 40Ar/ 39Ar ages of deformed biotite vary from 301 to 217 Ma, consistent with up to 32% 40Ar ∗ loss. No spatial correlation is observed between in situ40Ar/ 39Ar age and position within individual grains. Using available argon diffusion data for muscovite the observed 40Ar ∗ loss in the experimentally treated muscovite can be utilized to predict average 40Ar ∗ diffusion dimensions. Maximum 40Ar/ 39Ar ages

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

    USGS Publications Warehouse

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

    2004-01-01

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

  19. The differences in analysing strategy of viscosity experiment between freshmen and laboratory assistant

    NASA Astrophysics Data System (ADS)

    Anggrayni, S.; Mubarok, H.; Putri, N. P.; Suprapto, N.; Kholiq, A.

    2018-03-01

    The viscosity is defined by dimension of a fluid that resists the force tending to motive the fluid to flow. The aim of viscosity experiment is to determine the fluid viscosity coefficient value. By using graphical analysis, the result of oil viscosity coefficient value which performed by laboratory assistant showed: (1) 0.20 Pa.s using solid ball with accuracy 99.64% and (2) 0.21 Pa.s using smaller solid ball with accuracy 99.17%. Meanwhile, the result of oil viscosity coefficient value which performed by freshmen showed: (1) 0.44 Pa.s using solid ball with accuracy 87.85% and (2) 0.32 Pa.s using smaller solid ball with accuracy 89.84%. The differences result of the freshmen and assistant laboratory viscosity experiment are caused by the freshmen calculated the coefficient viscosity value without velocity correction factor and they used small range fluid so the times are not identified well.

  20. Laboratory experiments for understanding mechanical properties of fractured granite under supercritical conditions

    NASA Astrophysics Data System (ADS)

    Kitamura, M.; Takahashi, M.; Takagi, K.; Hirano, N.; Tsuchiya, N.

    2017-12-01

    To extract geothermal energy effectively and safely from magma and/or adjacent hot rock, we need to tackle many issues which require new technology development, such as a technique to control a risk from induced-earthquakes. On a development of induced-earthquake mitigation technology, it is required to understand roles of factors on occurrences of the induced-earthquake (e.g., strength, crack density, and fluid-rock reaction) and their intercorrelations (e.g., Asanuma et al., 2012). Our purpose of this series of experiments is to clarify a relationship between the rock strength and the crack density under supercritical conditions. We conducted triaxial deformation test on intact granite rock strength under high-temperature (250 - 750°C), high-pressure (104 MPa) condition at a constant load velocity (0.1 μm/sec) using a gas-rig at AIST. We used Oshima granite, which has initially <0.2 % of the porosity, 4.29±0.55 km/s in Vp (dry), and 2.49±0.19 km/s in Vs (dry). All experimental products showed the brittle feature having several oblique fracture surfaces, but the amount of stress drop became smaller at higher temperature. Young's modulus increased with decreasing the temperature from 32.3 GPa at 750°C to 57.4 GPa at 250°C. At 400 °C, the stress drop accelerated the deformation with 98 times faster velocity than that at load-point. In contrast, at 650°C and 750°C, the velocity during stress drop kept the same order of the load-point velocity. Therefore, the deformation mechanism may start to be changed from brittle to ductile when the temperature exceeds 650°C. Highly dense cracked granite specimens were formed by a rapid decompression test (RDT) using an autoclave settled at Tohoku University (Hirano et al., 2016JpGU), caused by a reduction of fluid pressure within 1-2 sec from vapor/supercritical state (10 - 48 MPa, 550 °C) to ambient pressure. The specimens after RDT show numerous microcracks on X-ray CT images. The RDT imposed the porosity increasing

  1. Effects of Structural Deformation and Tube Chirality on Electronic Conductance of Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Svizhenko, Alexei; Maiti, Amitesh; Anantram, M. P.; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    A combination of large scale classical force-field (UFF), density functional theory (DFT), and tight-binding Green's function transport calculations is used to study the electronic properties of carbon nanotubes under the twist, bending, and atomic force microscope (AFM)-tip deformation. We found that in agreement with experiment a significant change in electronic conductance can be induced by AFM-tip deformation of metallic zigzag tubes and by twist deformation of armchair tubes. The effect is explained in terms of bandstructure change under deformation.

  2. Impact of methane flow through deformable lake sediments on atmospheric release

    NASA Astrophysics Data System (ADS)

    Scandella, B.; Juanes, R.

    2010-12-01

    Methane is a potent greenhouse gas that is generated geothermally and biologically in lake and ocean sediments. Free gas bubbles may escape oxidative traps and contribute more to the atmospheric source than dissolved methane, but the details of the methane release depend on the interactions between the multiple fluid phases and the deformable porous medium. We present a model and supporting laboratory experiments of methane release through “breathing” dynamic flow conduits that open in response to drops in the hydrostatic load on lake sediments, which has been validated against a high-resolution record of free gas flux and hydrostatic pressure in Upper Mystic Lake, MA. In contrast to previous linear elastic fracture mechanics analysis of gassy sediments, the evolution of gas transport in a deformable compliant sediment is presented within the framework of multiphase poroplasticity. Experiments address how strongly the mode and rate of gas flow, captured by our model, impacts the size of bubbles released into the water column. A bubble's size in turn determines how efficiently it transports methane to the atmosphere, and integrating this effect will be critical to improving estimates of the atmospheric methane source from lakes. Cross-sectional schematic of lake sediments showing two venting sites: one open at left and one closed at right. The vertical release of gas bubbles (red) at the open venting site creates a local pressure drop, which drives both bubble formation from the methane-rich pore water (higher concentrations shaded darker red) and lateral advection of dissolved methane (purple arrows). Even as bubbles in the open site escape, those at the closed site remain trapped.

  3. Deformation of Fold-and-Thrust Belts above a Viscous Detachment: New Insights from Analogue Modelling Experiments

    NASA Astrophysics Data System (ADS)

    Nogueira, Carlos R.; Marques, Fernando O.

    2015-04-01

    Theoretical and experimental studies on fold-and-thrusts belts (FTB) have shown that, under Coulomb conditions, deformation of brittle thrust wedges above a dry frictional basal contact is characterized by dominant frontward vergent thrusts (forethrusts) with thrust spacing and taper angle being directly influenced by the basal strength (increase in basal strength leading to narrower thrust spacing and higher taper angles); whereas thrust wedges deformed above a weak viscous detachment, such as salt, show a more symmetric thrust style (no prevailing vergence of thrusting) with wider thrust spacing and shallower wedges. However, different deformation patterns can be found on this last group of thrust wedges both in nature and experimentally. Therefore we focused on the strength (friction) of the wedge basal contact, the basal detachment. We used a parallelepiped box with four fixed walls and one mobile that worked as a vertical piston drove by a computer controlled stepping motor. Fine dry sand was used as the analogue of brittle rocks and silicone putty (PDMS) with Newtonian behaviour as analogue of the weak viscous detachment. To investigate the strength of basal contact on thrust wedge deformation, two configurations were used: 1) a horizontal sand pack with a dry frictional basal contact; and 2) a horizontal sand pack above a horizontal PDMS layer, acting as a basal weak viscous contact. Results of the experiments show that: the model with a dry frictional basal detachment support the predictions for the Coulomb wedges, showing a narrow wedge with dominant frontward vergence of thrusting, close spacing between FTs and high taper angle. The model with a weak viscous frictional basal detachment show that: 1) forethrusts (FT) are dominant showing clearly an imbricate asymmetric geometry, with wider spaced thrusts than the dry frictional basal model; 2) after FT initiation, the movement on the thrust can last up to 15% model shortening, leading to great amount of

  4. FTIR measurements of OH in deformed quartz and feldspars of the South Tibetan Detachment, Greater Himalaya

    NASA Astrophysics Data System (ADS)

    Jezek, L.; Law, R. D.; Jessup, M. J.; Searle, M. P.; Kronenberg, A. K.

    2017-12-01

    OH absorption bands due to water in deformed quartz and feldspar grains of mylonites from the low-angle Lhotse Detachment (of the South Tibetan Detachment System, Rongbuk Valley north of Mount Everest) have been measured by Fourier Transform Infrared (FTIR) Spectroscopy. Previous microstructural studies have shown that these rocks deformed by dislocation creep at high temperature conditions in the middle crust (lower - middle amphibolite facies), and oxygen isotope studies suggest significant influx of meteoric water. OH absorption bands at 3400 cm-1 of quartz mylonites from the footwall of the Lhotse Detachment Fault are large, with the character of the molecular water band due to fluid inclusions in milky quartz. Mean water contents depend on structural position relative to the core of the Lhotse Detachment, from 1000 ppm (OH/106 Si) at 420 m below the fault to 11,350 (+/-1095) ppm near its center. The gradient in OH content shown by quartz grains implies influx of meteoric water along the Lhotse Detachment from the Tibetan Plateau ground surface to middle crustal depths, and significant fluid penetration into the extruding Himalayan slab by intergranular, permeable fluid flow processes. Feldspars of individual samples have comparable water contents to those of quartz and some are wetter. Large water contents of quartz and feldspar may have contributed to continued deformation and strain localization on the South Tibetan Detachment System. Dislocation creep in quartz is facilitated by water in laboratory experiments, and the water contents of the Lhotse fault rocks are similar to (and even larger than) water contents of quartz experimentally deformed during water weakening. Water contents of feldspars are comparable to those of plagioclase aggregates deformed experimentally by dislocation and diffusion creep under wet conditions.

  5. Low-cost nonlinear optics experiment for undergraduate instructional laboratory and lecture demonstration

    NASA Astrophysics Data System (ADS)

    Turchiello, Rozane de F.; Pereira, Luiz A. A.; Gómez, Sergio L.

    2017-07-01

    This paper presents a simple and affordable experiment on the thermal lens effect, suitable for an undergraduate educational laboratory or as a tabletop demonstration in a lecture on nonlinear optics. Such an experiment exploits the formation of a lens in an absorbing medium illuminated by a laser beam with a Gaussian intensity profile. As an absorber, we use a commercial soy sauce, which exhibits a strong thermal lensing effect. Additionally, we show how to measure the radius of a Gaussian beam using the knife-edge method, and how to estimate the focal length of the induced thermal lens.

  6. Mathematical models of carbon-carbon composite deformation

    NASA Astrophysics Data System (ADS)

    Golovin, N. N.; Kuvyrkin, G. N.

    2016-09-01

    Mathematical models of carbon-carbon composites (CCC) intended for describing the processes of deformation of structures produced by using CCC under high-temperature loading are considered. A phenomenological theory of CCC inelastic deformation is proposed, where such materials are considered as homogeneous ones with effective characteristics and where their high anisotropy of mechanical characteristics and different ways of resistance to extension and compression are taken into account. Micromechanical models are proposed for spatially reinforced CCC, where the difference between mechanical characteristics of components and the reinforcement scheme are taken into account. Themodel parameters are determined from the results of experiments of composite macrospecimens in the directions typical of the material. A version of endochronictype theory with several internal times "launched" for each composite component and related to some damage accumulation mechanisms is proposed for describing the inelastic deformation. Some practical examples are considered.

  7. A study of the micro- and nanoscale deformation behavior of individual austenitic dendrites in a FeCrMoVC cast alloy using micro- and nanoindentation experiments

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zeisig, J., E-mail: j.zeisig@ifw-dresden.de; Hufenbach, J.; Wendrock, H.

    2016-04-04

    Micro- and nanoindentation experiments were conducted to investigate the deformation mechanisms in a Fe79.4Cr13Mo5V1C1.6 (wt. %) cast alloy. This alloy consists of an as cast microstructure mainly composed of austenite, martensite, and a complex carbide network. During microhardness testing, metastable austenite transforms partially into martensite confirmed by electron backscatter diffraction. For nanoindentation tests, two different indenter geometries were applied (Berkovich and cube corner type). Load-displacement curves of nanoindentation in austenitic dendrites depicted pop-ins after transition into plastic deformation for both nanoindenters. Characterizations of the region beneath a nanoindent by transmission electron microscopy revealed a martensitic transformation as an activated deformationmore » mechanism and suggest a correlation with the pop-in phenomena of the load-displacement curves. Furthermore, due to an inhomogeneous chemical composition within the austenitic dendrites, more stabilized regions deform by mechanical twinning. This additional deformation mechanism was only observed for the cube corner indenter with the sharper geometry since higher shear stresses are induced beneath the contact area.« less

  8. A wideband magnetoresistive sensor for monitoring dynamic fault slip in laboratory fault friction experiments

    USGS Publications Warehouse

    Kilgore, Brian D.

    2017-01-01

    A non-contact, wideband method of sensing dynamic fault slip in laboratory geophysical experiments employs an inexpensive magnetoresistive sensor, a small neodymium rare earth magnet, and user built application-specific wideband signal conditioning. The magnetoresistive sensor generates a voltage proportional to the changing angles of magnetic flux lines, generated by differential motion or rotation of the near-by magnet, through the sensor. The performance of an array of these sensors compares favorably to other conventional position sensing methods employed at multiple locations along a 2 m long × 0.4 m deep laboratory strike-slip fault. For these magnetoresistive sensors, the lack of resonance signals commonly encountered with cantilever-type position sensor mounting, the wide band response (DC to ≈ 100 kHz) that exceeds the capabilities of many traditional position sensors, and the small space required on the sample, make them attractive options for capturing high speed fault slip measurements in these laboratory experiments. An unanticipated observation of this study is the apparent sensitivity of this sensor to high frequency electomagnetic signals associated with fault rupture and (or) rupture propagation, which may offer new insights into the physics of earthquake faulting.

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

    ERIC Educational Resources Information Center

    Prigodich, Richard V.

    2014-01-01

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

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

    ERIC Educational Resources Information Center

    Valley Springs School District 2, AR.

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

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  13. Environmental fate and behavior of acesulfame in laboratory experiments.

    PubMed

    Storck, Florian R; Skark, Christian; Remmler, Frank; Brauch, Heinz-Jürgen

    2016-12-01

    Acesulfame is a widely used artificial sweetener. It can be discharged into surface water by domestic wastewater due to its incomplete retention during wastewater treatment. Concentrations may reach up to 10 μg/L for smaller rivers. State-of-the-art analysis allows the determination of acesulfame traces (0.01 μg/L) and thus a potential tracking of the presence of wastewater in riverbank filtrate. To evaluate the behavior of acesulfame in the aquatic environment, biodegradation and sorption of acesulfame were tested. Batch experiments yielded low sorption for several soils (estimated solid-water distribution coefficient of acesulfame <0.1 L/kg). Biodegradation in a fixed-bed reactor was not observed at environmental concentrations of 9 μg/L in aqueous compost and soil extract (observation period 56 days). Only in diluted effluent of a wastewater treatment plant did biodegradation start, after 17 days of operation, and acesulfame completely fade, within 28 days. Flow-through column experiments indicated conservative behavior of acesulfame (recovery >83%) and long-term observations at different concentration levels yielded no biodegradation. Overall, laboratory experiments demonstrated a conservative behavior of acesulfame under conditions typical for riverbank filtration. However, there are hints for certain settings which favor an adaptation of the microbial community and facilitate a rapid biodegradation of acesulfame.

  14. 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.

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

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  16. Spatiotemporal seismic velocity change in the Earth's subsurface associated with large earthquake: contribution of strong ground motion and crustal deformation

    NASA Astrophysics Data System (ADS)

    Sawazaki, K.

    2016-12-01

    It is well known that seismic velocity of the subsurface medium changes after a large earthquake. The cause of the velocity change is roughly attributed to strong ground motion (dynamic strain change), crustal deformation (static strain change), and fracturing around the fault zone. Several studies have revealed that the velocity reduction down to several percent concentrates at the depths shallower than several hundred meters. The amount of velocity reduction correlates well with the intensity of strong ground motion, which indicates that the strong motion is the primary cause of the velocity reduction. Although some studies have proposed contributions of coseismic static strain change and fracturing around fault zone to the velocity change, separation of their contributions from the site-related velocity change is usually difficult. Velocity recovery after a large earthquake is also widely observed. The recovery process is generally proportional to logarithm of the lapse time, which is similar to the behavior of "slow dynamics" recognized in laboratory experiments. The time scale of the recovery is usually months to years in field observations, while it is several hours in laboratory experiments. Although the factor that controls the recovery speed is not well understood, cumulative strain change due to post-seismic deformation, migration of underground water, mechanical and chemical reactions on the crack surface could be the candidate. In this study, I summarize several observations that revealed spatiotemporal distribution of seismic velocity change due to large earthquakes; especially I focus on the case of the M9.0 2011 Tohoku earthquake. Combining seismograms of Hi-net (high-sensitivity) and KiK-net (strong motion), geodetic records of GEONET and the seafloor GPS/Acoustic ranging, I investigate contribution of the strong ground motion and crustal deformation to the velocity change associated with the Tohoku earthquake, and propose a gross view of

  17. The testing effect for mediator final test cues and related final test cues in online and laboratory experiments.

    PubMed

    Coppens, Leonora C; Verkoeijen, Peter P J L; Bouwmeester, Samantha; Rikers, Remy M J P

    2016-05-31

    The testing effect is the finding that information that is retrieved during learning is more often correctly retrieved on a final test than information that is restudied. According to the semantic mediator hypothesis the testing effect arises because retrieval practice of cue-target pairs (mother-child) activates semantically related mediators (father) more than restudying. Hence, the mediator-target (father-child) association should be stronger for retrieved than restudied pairs. Indeed, Carpenter (2011) found a larger testing effect when participants received mediators (father) than when they received target-related words (birth) as final test cues. The present study started as an attempt to test an alternative account of Carpenter's results. However, it turned into a series of conceptual (Experiment 1) and direct (Experiment 2 and 3) replications conducted with online samples. The results of these online replications were compared with those of similar existing laboratory experiments through small-scale meta-analyses. The results showed that (1) the magnitude of the raw mediator testing effect advantage is comparable for online and laboratory experiments, (2) in both online and laboratory experiments the magnitude of the raw mediator testing effect advantage is smaller than in Carpenter's original experiment, and (3) the testing effect for related cues varies considerably between online experiments. The variability in the testing effect for related cues in online experiments could point toward moderators of the related cue short-term testing effect. The raw mediator testing effect advantage is smaller than in Carpenter's original experiment.

  18. Simulating intracrater ash recycling during mid-intensity explosive activity: high temperature laboratory experiments on natural basaltic ash

    NASA Astrophysics Data System (ADS)

    D'Oriano, Claudia; Pompilio, Massimo; Bertagnini, Antonella; Cioni, Raffaello; Pichavant, Michel

    2010-05-01

    Direct observations of mid-intensity eruptions, in which a huge amount of ash is generated, indicate that ash recycling is quite common. The recognition of juvenile vs. recycled fragments is not straightforward, and no unequivocal, widely accepted criteria exist to support this. The presence of recycled glassy fragments can hide primary magmatic information, introducing bias in the interpretations of the ongoing magmatic and volcanic activity. High temperature experiments were performed at atmospheric pressure on natural samples to investigate the effects of reheating on morphology, texture and composition of volcanic ash. Experiments simulate the transformation of juvenile glassy fragments that, falling into the crater or in the upper part of the conduit, are recycled by following explosions. Textural and compositional modifications obtained in laboratory are compared with similar features observed in natural samples in order to identify some main general criteria to be used for the discrimination of recycled material. Experiments were carried out on tephra produced during Strombolian activity, fire fountains and continuous ash emission at Etna, Stromboli and Vesuvius. Coarse glassy clasts were crushed in a nylon mortar in order to create an artificial ash, and then sieved to select the size interval of 1-0.71 mm. Ash shards were put in a sealed or open quartz tube, in order to prevent or to reproduce effects of air oxidation. The tube was suspended in a HT furnace at INGV-Pisa and kept at different temperatures (up to to 1110°C) for increasing time (0.5-12 hours). Preliminary experiments were also performed under gas flux conditions. Optical and electron microscope observations indicate that high temperature and exposure to the air induce large modifications on clast surface, ranging from change in color, to incipient plastic deformation till complete sintering. Significant change in color of clasts is strictly related to the presence of air, irrespective of

  19. The Model Experiments and Finite Element Analysis on Deformation and Failure by Excavation of Grounds in Foregoing-roof Method

    NASA Astrophysics Data System (ADS)

    Sotokoba, Yasumasa; Okajima, Kenji; Iida, Toshiaki; Tanaka, Tadatsugu

    We propose the trenchless box culvert construction method to construct box culverts in small covering soil layers while keeping roads or tracks open. When we use this construction method, it is necessary to clarify deformation and shear failure by excavation of grounds. In order to investigate the soil behavior, model experiments and elasto-plactic finite element analysis were performed. In the model experiments, it was shown that the shear failure was developed from the end of the roof to the toe of the boundary surface. In the finite element analysis, a shear band effect was introduced. Comparing the observed shear bands in model experiments with computed maximum shear strain contours, it was found that the observed direction of the shear band could be simulated reasonably by the finite element analysis. We may say that the finite element method used in this study is useful tool for this construction method.

  20. A Multistep Organocatalysis Experiment for the Undergraduate Organic Laboratory: An Enantioselective Aldol Reaction Catalyzed by Methyl Prolinamide

    ERIC Educational Resources Information Center

    Wade, Edmir O.; Walsh, Kenneth E.

    2011-01-01

    In recent years, there has been an explosion of research concerning the area of organocatalysis. A multistep capstone laboratory project that combines traditional reactions frequently found in organic laboratory curriculums with this new field of research is described. In this experiment, the students synthesize a prolinamide-based organocatalyst…

  1. Immersion and contact freezing experiments in the Mainz wind tunnel laboratory

    NASA Astrophysics Data System (ADS)

    Eppers, Oliver; Mayer, Amelie; Diehl, Karoline; Mitra, Subir; Borrmann, Stephan; Szakáll, Miklós

    2016-04-01

    Immersion and contact freezing are of outmost important ice nucleation processes in mixed phase clouds. Experimental studies are carried out in the Mainz vertical wind tunnel laboratory in order to characterize these nucleation processes for different ice nucleating particles (INP), such as for mineral dust or biological particles. Immersion freezing is investigated in our laboratory with two different experimental techniques, both attaining contact-free levitation of liquid droplets and cooling of the surrounding air down to about -25 °C. In an acoustic levitator placed in the cold room of our laboratory, drops with diameters of 2 mm are investigated. In the vertical air stream of the wind tunnel droplets with diameter of 700 micron are freely floated at their terminal velocities, simulating the flow conditions of the free atmosphere. Furthermore, the wind tunnel offers a unique platform for contact freezing experiments. Supercooled water droplets are floated in the vertical air stream at their terminal velocities and INP are injected into the tunnel air stream upstream of them. As soon as INP collides with the supercooled droplet the contact freezing is initiated. The first results of immersion and contact freezing experiments with cellulose particles both in the acoustic levitator and in the wind tunnel will be presented. Cellulose is considered as typical INP of biological origin and a macrotracer for plant debris. Nucleating properties of cellulose will be provided, mainly focusing on the temperature, INP concentration, and specific surface area dependences of the freezing processes. Direct comparison between the different experimental techniques (acoustic levitator and wind tunnel), as well as between nucleation modes (immersion and contact freezing) will be presented. The work is carried out within the framework of the German research unit INUIT.

  2. Anatomy and humanity: Examining the effects of a short documentary film and first anatomy laboratory experience on medical students.

    PubMed

    Dosani, Farah; Neuberger, Lindsay

    2016-01-01

    Medical students begin their education inside a laboratory dissecting cadavers to learn human gross anatomy. Many schools use the course experience as a way to instill empathy and some have begun integrating video and recorded interviews with body donors to humanize the experience, but their impact has yet to be measured. This study examines the effects of a brief documentary film and the initial cadaver encounter on student perceptions and attitudes towards the laboratory experience. A pre-test, exposure, post-test design was used with 77 first-year medical students at the University of Central Florida. A previously validated questionnaire was adapted to measure attitudes, emotions, initial reaction to cadaver, perception of the donor as a person, and impressions of the film. An online questionnaire was completed before the first day of laboratory, in which students watched the film Anatomy and Humanity and handled their respective cadavers (no dissection was performed). The post-test was administered immediately following the activities of the first laboratory day. Results indicate an increase in negative attitudes towards dissection, but a more positive initial reaction to the cadaver than originally anticipated. Students also experienced a decrease in emotions like sadness and guilt regarding anatomy laboratory and were less likely to view the cadaver as a once-living person. Findings suggest a higher comfort level, but also greater detachment toward the cadavers from day one despite the video intervention. These results provide novel insight that may aid other interventions aimed at promoting humanism in the anatomy laboratory experience. © 2015 American Association of Anatomists.

  3. Viscoelastic deformation of lipid bilayer vesicles†

    PubMed Central

    Wu, Shao-Hua; Sankhagowit, Shalene; Biswas, Roshni; Wu, Shuyang; Povinelli, Michelle L.

    2015-01-01

    Lipid bilayers form the boundaries of the cell and its organelles. Many physiological processes, such as cell movement and division, involve bending and folding of the bilayer at high curvatures. Currently, bending of the bilayer is treated as an elastic deformation, such that its stress-strain response is independent of the rate at which bending strain is applied. We present here the first direct measurement of viscoelastic response in a lipid bilayer vesicle. We used a dual-beam optical trap (DBOT) to stretch 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) giant unilamellar vesicles (GUVs). Upon application of a step optical force, the vesicle membrane deforms in two regimes: a fast, instantaneous area increase, followed by a much slower stretching to an eventual plateau deformation. From measurements of dozens of GUVs, the average time constant of the slower stretching response was 0.225 ± 0.033 s (standard deviation, SD). Increasing the fluid viscosity did not affect the observed time constant. We performed a set of experiments to rule out heating by laser absorption as a cause of the transient behavior. Thus, we demonstrate here that the bending deformation of lipid bilayer membranes should be treated as viscoelastic. PMID:26268612

  4. Apoptosis as the focus of an authentic research experience in a cell physiology laboratory.

    PubMed

    Byrd, Shere K

    2016-06-01

    Curriculum-embedded independent research is a high-impact teaching practice that has been shown to increase student engagement and learning. This article describes a multiweek laboratory project for an upper-division undergraduate cell physiology laboratory using apoptosis via the mitochondrial pathway as the overarching theme. Students did literature research on apoptotic agents that acted via the mitochondrial pathway. Compounds ranged from natural products such as curcumin to synthetic compounds such as etoposide. Groups of two to three students planned a series of experiments using one of three cultured cell lines that required them to 1) learn to culture cells; 2) determine treatment conditions, including apoptotic agent solubility and concentration ranges that had been reported in the literature; 3) choose two methods to validate/quantify apoptotic capacity of the reagent; and 4) attempt to "rescue" cells from undergoing apoptosis using one of several available compounds/methods. In essence, given some reagent and equipment constraints, students designed an independent experiment to highlight the effects of different apoptotic agents on cells in culture. Students presented their experimental designs as in a laboratory group meeting and their final findings as a classroom "symposium." This exercise can be adapted to many different types of laboratories with greater or lesser equipment and instrumentation constraints, incorporates several core cell physiology methods, and encourages key experimental design and critical thinking components of independent research. Copyright © 2016 The American Physiological Society.

  5. Global synthesis of volcano deformation: Results of the Volcano Deformation Task Force

    NASA Astrophysics Data System (ADS)

    Pritchard, M. E.; Jay, J.; Biggs, J.; Ebmeier, S. K.; Delgado, F.

    2013-12-01

    Ground deformation in volcanic regions is being observed more frequently -- the number of known deforming volcanoes has increased from 44 in 1997 to more than 210 in 2013 thanks in large part thanks to the availability of satellite InSAR observations. With the launch of new SAR satellites in the coming years devoted to global deformation monitoring, the number of well-studied episodes of volcano deformation will continue to increase. But evaluating the significance of the observed deformation is not always straightforward -- how often do deformation episodes lead to eruption? Are there certain characteristics of the deformation or the volcano that make the linkage between deformation and eruption more robust -- for example the duration or magnitude of the ground deformation and/or the composition and tectonic setting of the volcano? To answer these questions, a global database of volcano deformation events is needed. Recognizing the need for global information on volcano deformation and the opportunity to address it with InSAR and other techniques, we formed the Volcano Deformation Database Task force as part of Global Volcano Model. The three objectives of our organization are: 1) to compile deformation observations of all volcanoes globally into appropriate formats for WOVOdat and the Global Volcanism Program of the Smithsonian Institution. 2) document any relation between deformation events and eruptions for the Global assessment of volcanic hazard and risk report for 2015 (GAR15) for the UN. 3) to better link InSAR and other remote sensing observations to volcano observatories. We present the first results from our global study of the relation between deformation and eruptions, including case studies of particular eruptions. We compile a systematically-observed catalog of >500 volcanoes with observation windows up to 20 years. Of 90 volcanoes showing deformation, 40 erupted. The positive predictive value (PPV = 0.44) linking deformation and eruption on this

  6. Appraisal of transport and deformation in shale reservoirs using natural noble gas tracers

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Heath, Jason E.; Kuhlman, Kristopher L.; Robinson, David G.

    2015-09-01

    This report presents efforts to develop the use of in situ naturally-occurring noble gas tracers to evaluate transport mechanisms and deformation in shale hydrocarbon reservoirs. Noble gases are promising as shale reservoir diagnostic tools due to their sensitivity of transport to: shale pore structure; phase partitioning between groundwater, liquid, and gaseous hydrocarbons; and deformation from hydraulic fracturing. Approximately 1.5-year time-series of wellhead fluid samples were collected from two hydraulically-fractured wells. The noble gas compositions and isotopes suggest a strong signature of atmospheric contribution to the noble gases that mix with deep, old reservoir fluids. Complex mixing and transport of fracturingmore » fluid and reservoir fluids occurs during production. Real-time laboratory measurements were performed on triaxially-deforming shale samples to link deformation behavior, transport, and gas tracer signatures. Finally, we present improved methods for production forecasts that borrow statistical strength from production data of nearby wells to reduce uncertainty in the forecasts.« less

  7. Role of Laboratory Plasma Experiments in exploring the Physics of Solar Eruptions

    NASA Astrophysics Data System (ADS)

    Tripathi, S.

    2017-12-01

    Solar eruptive events are triggered over a broad range of spatio-temporal scales by a variety of fundamental processes (e.g., force-imbalance, magnetic-reconnection, electrical-current driven instabilities) associated with arched magnetoplasma structures in the solar atmosphere. Contemporary research on solar eruptive events is at the forefront of solar and heliospheric physics due to its relevance to space weather. Details on the formation of magnetized plasma structures on the Sun, storage of magnetic energy in such structures over a long period (several Alfven transit times), and their impulsive eruptions have been recorded in numerous observations and simulated in computer models. Inherent limitations of space observations and uncontrolled nature of solar eruptions pose significant challenges in testing theoretical models and developing the predictive capability for space-weather. The pace of scientific progress in this area can be significantly boosted by tapping the potential of appropriately scaled laboratory plasma experiments to compliment solar observations, theoretical models, and computer simulations. To give an example, recent results from a laboratory plasma experiment on arched magnetic flux ropes will be presented and future challenges will be discussed. (Work supported by National Science Foundation, USA under award number 1619551)

  8. Small Laccase from "Streptomyces Coelicolor"--An Ideal Model Protein/Enzyme for Undergraduate Laboratory Experience

    ERIC Educational Resources Information Center

    Cook, Ryan; Hannon, Drew; Southard, Jonathan N.; Majumdar, Sudipta

    2018-01-01

    A one semester undergraduate biochemistry laboratory experience is described for an understanding of recombinant technology from gene cloning to protein characterization. An integrated experimental design includes three sequential modules: molecular cloning, protein expression and purification, and protein analysis and characterization. Students…

  9. Five biomedical experiments flown in an Earth orbiting laboratory: Lessons learned from developing these experiments on the first international microgravity mission from concept to landing

    NASA Technical Reports Server (NTRS)

    Winget, C. M.; Lashbrook, J. J.; Callahan, P. X.; Schaefer, R. L.

    1993-01-01

    There are numerous problems associated with accommodating complex biological systems in microgravity in the flexible laboratory systems installed in the Orbiter cargo bay. This presentation will focus upon some of the lessons learned along the way from the University laboratory to the IML-1 Microgravity Laboratory. The First International Microgravity Laboratory (IML-1) mission contained a large number of specimens, including: 72 million nematodes, US-1; 3 billion yeast cells, US-2; 32 million mouse limb-bud cells, US-3; and 540 oat seeds (96 planted), FOTRAN. All five of the experiments had to undergo significant redevelopment effort in order to allow the investigator's ideas and objectives to be accommodated within the constraints of the IML-1 mission. Each of these experiments were proposed as unique entities rather than part of the mission, and many procedures had to be modified from the laboratory practice to meet IML-1 constraints. After a proposal is accepted by NASA for definition, an interactive process is begun between the Principal Investigator and the developer to ensure a maximum science return. The success of the five SLSPO-managed experiments was the result of successful completion of all preflight biological testing and hardware verification finalized at the KSC Life Sciences Support Facility housed in Hangar L. The ESTEC Biorack facility housed three U.S. experiments (US-1, US-2, and US-3). The U.S. Gravitational Plant Physiology Facility housed GTHRES and FOTRAN. The IML-1 mission (launched from KSC on 22 Jan. 1992, and landed at Dryden Flight Research Facility on 30 Jan. 1992) was an outstanding success--close to 100 percent of the prelaunch anticipated science return was achieved and, in some cases, greater than 100 percent was achieved (because of an extra mission day).

  10. The emerging understanding of magnetic reconnection through laboratory experiments, theory and modeling and in situ satellite measurements

    NASA Astrophysics Data System (ADS)

    Drake, James F.

    2015-08-01

    Magnetic reconnection is the driver of explosive energy release in laboratory, space and astrophysical plasma systems. It plays a centralrole in such diverse phenomena as solar and stellar flares, flares in pulsar nebulae, gamma ray bursts and possibly even in the productionof energetic particles in supernova shocks. The close interaction of scientists doing laboratory experiments, in situ satellite measurements and theory and modeling has led to remarkable progress on key issues such as the mechanisms for fast energy release and heating and particle acceleration. There are, however, many open issues. The talk will address the emerging understanding of reconnection as well as areas where significant uncertainty remains. The role of new laboratory experiments such as FLARE at PPPL and the recently launched four-spacecraft MMS mission in resolving open issues will be discussed.

  11. Testing a common ice-ocean parameterization with laboratory experiments

    NASA Astrophysics Data System (ADS)

    McConnochie, C. D.; Kerr, R. C.

    2017-07-01

    Numerical models of ice-ocean interactions typically rely upon a parameterization for the transport of heat and salt to the ice face that has not been satisfactorily validated by observational or experimental data. We compare laboratory experiments of ice-saltwater interactions to a common numerical parameterization and find a significant disagreement in the dependence of the melt rate on the fluid velocity. We suggest a resolution to this disagreement based on a theoretical analysis of the boundary layer next to a vertical heated plate, which results in a threshold fluid velocity of approximately 4 cm/s at driving temperatures between 0.5 and 4°C, above which the form of the parameterization should be valid.

  12. Texture and phase analysis of deformed SUS304 by using HIPPO

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Takajo, Shigehiro; Vogel, Sven C.

    2016-11-15

    These slides represent the author's research activity at Los Alamos National Laboratory (LANL), which is about texture and phase analysis of deformed SUS304 by using HIPPO. The following topics are covered: diffraction histogram at each sample position, diffraction histogram (all bank data averaged), possiblity of ε-phase, MAUD analysis with including ε-phase.

  13. 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.

  14. A multi-conjugate adaptive optics testbed using two MEMS deformable mirrors

    NASA Astrophysics Data System (ADS)

    Andrews, Jonathan R.; Martinez, Ty; Teare, Scott W.; Restaino, Sergio R.; Wilcox, Christopher C.; Santiago, Freddie; Payne, Don M.

    2011-03-01

    Adaptive optics (AO) systems are well demonstrated in the literature with both laboratory and real-world systems being developed. Some of these systems have employed MEMS deformable mirrors as their active corrective element. More recent work in AO for astronomical applications has focused on providing correction in more than one conjugate plane. Additionally, horizontal path AO systems are exploring correction in multiple conjugate planes. This provides challenges for a laboratory system as the aberrations need to be generated and corrected in more than one plane in the optical system. Our work with compact AO systems employing MEMS technology in addition to liquid crystal spatial light modulator (SLM) driven aberration generators has been scaled up to a two conjugate plane testbed. Using two SLM based aberration generators and two separate wavefront sensors, the system can apply correction with two MEMS deformable mirrors. The challenges in such a system are to properly match non-identical components and weight the correction algorithm for correcting in two planes. This paper demonstrates preliminary results and analysis with this system with wavefront data and residual error measurements.

  15. Tension-dependent structural deformation alters single-molecule transition kinetics

    PubMed Central

    Sudhanshu, B.; Mihardja, S.; Koslover, E. F.; Mehraeen, S.; Bustamante, C.; Spakowitz, A. J.

    2011-01-01

    We analyze the response of a single nucleosome to tension, which serves as a prototypical biophysical measurement where tension-dependent deformation alters transition kinetics. We develop a statistical-mechanics model of a nucleosome as a wormlike chain bound to a spool, incorporating fluctuations in the number of bases bound, the spool orientation, and the conformations of the unbound polymer segments. With the resulting free-energy surface, we perform dynamic simulations that permit a direct comparison with experiments. This simple approach demonstrates that the experimentally observed structural states at nonzero tension are a consequence of the tension and that these tension-induced states cease to exist at zero tension. The transitions between states exhibit substantial deformation of the unbound polymer segments. The associated deformation energy increases with tension; thus, the application of tension alters the kinetics due to tension-induced deformation of the transition states. This mechanism would arise in any system where the tether molecule is deformed in the transition state under the influence of tension. PMID:21245354

  16. Stratospheric controlled perturbation experiment (SCoPEx): overview, status, and results from related laboratory experiments

    NASA Astrophysics Data System (ADS)

    Keith, D.; Dykema, J. A.; Keutsch, F. N.

    2017-12-01

    Stratospheric Controlled Perturbation Experiment (SCoPEx), is a scientific experiment to advance understanding of stratospheric aerosols. It aims to make quantitative measurements of aerosol microphysics and atmospheric chemistry to improve large-scale models used to assess the risks and benefits of solar geoengineering. A perturbative experiment requires: (a) means to create a well-mixed, small perturbed volume, and (b) observation of time evolution of chemistry and aerosols in the volume. SCoPEx will used a propelled balloon gondola containing all instruments and drive system. The propeller wake forms a well-mixed volume (roughly 1 km long and 100 meters in diameter) that serves as an experimental `beaker' into which aerosols (e.g., < 1 kg of 0.3 µm radius CaCO3 particles) at can be injected; while, the propellers allow the gondola to move at speeds up to 3 m/sec relative to the local air mass driving the gondola back forth through the volume to measure properties of the perturbed air mass. This presentation will provide an overview of the experiment including (a) a systems engineering perspective from high-level scientific questions through instrument selection, mission design, and proposed operations and data analysis; (b) instruments, include current status of integration testing; (c) payload engineering including structure, power and mass budget, etc; (d) results from CFD simulation of propeller wake and simulation of chemistry and aerosol microphysics; and finally (e) proposed concept of operations and schedule. We will also provide an overview of the plans for governance including management of health safety and environmental risks, transparency, public engagement, and larger questions about governance of solar geoengineering experiments. Finally, we will briefly present results of laboratory experiments of the interaction of chemical such as ClONO2 and HCl on particle surfaces relevant for stratospheric solar geoengineering.

  17. Mixing-dependent Reactions in the Hyporheic Zone: Laboratory and Numerical Experiments

    NASA Astrophysics Data System (ADS)

    Santizo, K. Y.; Eastes, L. A.; Hester, E. T.; Widdowson, M.

    2017-12-01

    The hyporheic zone is the surface water-groundwater interface surrounding the river's perimeter. Prior research demonstrates the ability of the hyporheic zone to attenuate pollutants when surface water cycles through reactive sediments (non-mixing-dependent reactions). However, the colocation of both surface and ground water within hyporheic sediments also allows mixing-dependent reactions that require mixing of reactants from these two water sources. Recent modeling studies show these mixing zones can be small under steady state homogeneous conditions, but do not validate those results in the laboratory or explore the range of hydrological characteristics that control the extent of mixing. Our objective was to simulate the mixing zone, quantify its thickness, and probe its hydrological controls using a "mix" of laboratory and numerical experiments. For the lab experiments, a hyporheic zone was simulated in a sand mesocosm, and a mixing-dependent abiotic reaction of sodium sulfite and dissolved oxygen was induced. Oxygen concentration response and oxygen consumption were visualized via planar optodes. Sulfate production by the mixing-dependent reaction was measured by fluid samples and a spectrophometer. Key hydrologic controls varied in the mesocosm included head gradient driving hyporheic exchange and hydraulic conductivity/heterogeneity. Results show a clear mixing area, sulfate production, and oxygen gradient. Mixing zone length (hyporheic flow cell size) and thickness both increase with the driving head gradient. For the numerical experiments, transient surface water boundary conditions were implemented together with heterogeneity of hydraulic conductivity. Results indicate that both fluctuating boundary conditions and heterogeneity increase mixing-dependent reaction. The hyporheic zone is deemed an attenuation hotspot by multiple studies, but here we demonstrate its potential for mixing-dependent reactions and the influence of important hydrological

  18. Design Your Own Workup: A Guided-Inquiry Experiment for Introductory Organic Laboratory Courses

    ERIC Educational Resources Information Center

    Mistry, Nimesh; Fitzpatrick, Christopher; Gorman, Stephen

    2016-01-01

    A guided-inquiry experiment was designed and implemented in an introductory organic chemistry laboratory course. Students were given a mixture of compounds and had to isolate two of the components by designing a viable workup procedure using liquid-liquid separation methods. Students were given the opportunity to apply their knowledge of chemical…

  19. Mechanical Failure Mode of Metal Nanowires: Global Deformation versus Local Deformation

    PubMed Central

    Ho, Duc Tam; Im, Youngtae; Kwon, Soon-Yong; Earmme, Youn Young; Kim, Sung Youb

    2015-01-01

    It is believed that the failure mode of metal nanowires under tensile loading is the result of the nucleation and propagation of dislocations. Such failure modes can be slip, partial slip or twinning and therefore they are regarded as local deformation. Here we provide numerical and theoretical evidences to show that global deformation is another predominant failure mode of nanowires under tensile loading. At the global deformation mode, nanowires fail with a large contraction along a lateral direction and a large expansion along the other lateral direction. In addition, there is a competition between global and local deformations. Nanowires loaded at low temperature exhibit global failure mode first and then local deformation follows later. We show that the global deformation originates from the intrinsic instability of the nanowires and that temperature is a main parameter that decides the global or local deformation as the failure mode of nanowires. PMID:26087445

  20. Varying iron release from transferrin and lactoferrin proteins. A laboratory experiment.

    PubMed

    Carmona, Fernando; González, Ana; Sánchez, Manu; Gálvez, Natividad; Cuesta, Rafael; Capdevila, Mercè; Dominguez-Vera, Jose M

    2017-11-01

    Iron metabolism is an important subject of study for undergraduate students of chemistry and biochemistry. Relevant laboratory exercises are scarce in the literature but would be very helpful in assisting students grasp key concepts. The experiment described here deals with different iron release mechanisms of two protagonists in iron metabolism: serum transferrin (Tf) and lactoferrin (Lf). Despite having very similar structures and iron-binding sites, Tf releases practically all its iron at pH 5.5 while Lf requires a significantly lower pH of 3. This difference in behavior is directly related to their respective biological functions as Tf blood-borne iron into the cell, while Lf competes with pathogens to sequester iron in biological fluids at more acidic pHs.  During this experiment, the students will carry out iron loading and unloading on both human Lf and Tf and monitor the iron release at different pHs using UV-Vis spectroscopy. With this simple approach, the students will discover the different patterns of iron release of Tf and Lf and how this variance in behavior relates to their biological functions. Furthermore, this laboratory practice can be expanded to allow students to investigate a variety of iron proteins. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(6):521-527, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

  1. Interactive virtual optical laboratories

    NASA Astrophysics Data System (ADS)

    Liu, Xuan; Yang, Yi

    2017-08-01

    Laboratory experiences are essential for optics education. However, college students have limited access to advanced optical equipment that is generally expensive and complicated. Hence there is a need for innovative solutions to expose students to advanced optics laboratories. Here we describe a novel approach, interactive virtual optical laboratory (IVOL) that allows unlimited number of students to participate the lab session remotely through internet, to improve laboratory education in photonics. Although students are not physically conducting the experiment, IVOL is designed to engage students, by actively involving students in the decision making process throughout the experiment.

  2. A new approach to characterize the effect of fabric deformation on thermal protective performance

    NASA Astrophysics Data System (ADS)

    Li, Jun; Li, Xiaohui; Lu, Yehu; Wang, Yunyi

    2012-04-01

    It is very important to evaluate thermal protective performance (TPP) in laboratory-simulated fire scenes as accurately as possible. For this paper, to thoroughly understand the effect of fabric deformation on basic physical properties and TPP of flame-retardant fabrics exposed to flash fire, a new modified TPP testing apparatus was developed. Different extensions were employed to simulate the various extensions displayed during different body motions. The tests were also carried out with different air gaps. The results showed a significant decrease in air permeability after deformation. However, the change of thickness was slight. The fabric deformation had a complicated effect on thermal protection with different air gaps. The change of TPP depended on the balance between the surface contact area and the thermal insulation. The newly developed testing apparatus could be well employed to evaluate the effect of deformation on TPP of flame-resistant fabrics.

  3. Modelling deformation and fracture in confectionery wafers

    NASA Astrophysics Data System (ADS)

    Mohammed, Idris K.; Charalambides, Maria N.; Williams, J. Gordon; Rasburn, John

    2015-01-01

    The aim of this research is to model the deformation and fracture behaviour of brittle wafers often used in chocolate confectionary products. Three point bending and compression experiments were performed on beam and circular disc samples respectively to determine the 'apparent' stress-strain curves in bending and compression. The deformation of the wafer for both these testing types was observed in-situ within an SEM. The wafer is modeled analytically and numerically as a composite material with a core which is more porous than the skins. X-ray tomography was used to generate a three dimensional volume of the wafer microstructure which was then meshed and used for quantitative analysis. A linear elastic material model, with a damage function and element deletion, was used and the XMT generated architecture was loaded in compression. The output from the FE simulations correlates closely to the load-deflection deformation observed experimentally.

  4. Biotechnology Laboratory Methods.

    ERIC Educational Resources Information Center

    Davis, Robert H.; Kompala, Dhinakar S.

    1989-01-01

    Describes a course entitled "Biotechnology Laboratory" which introduces a variety of laboratory methods associated with biotechnology. Describes the history, content, and seven experiments of the course. The seven experiments are selected from microbiology and molecular biology, kinetics and fermentation, and downstream…

  5. Deformation-resembling microstructure created by fluid-mediated dissolution-precipitation reactions.

    PubMed

    Spruzeniece, Liene; Piazolo, Sandra; Maynard-Casely, Helen E

    2017-01-27

    Deformation microstructures are widely used for reconstructing tectono-metamorphic events recorded in rocks. In crustal settings deformation is often accompanied and/or succeeded by fluid infiltration and dissolution-precipitation reactions. However, the microstructural consequences of dissolution-precipitation in minerals have not been investigated experimentally. Here we conducted experiments where KBr crystals were reacted with a saturated KCl-H 2 O fluid. The results show that reaction products, formed in the absence of deformation, inherit the general crystallographic orientation from their parents, but also display a development of new microstructures that are typical in deformed minerals, such as apparent bending of crystal lattices and new subgrain domains, separated by low-angle and, in some cases, high-angle boundaries. Our work suggests that fluid-mediated dissolution-precipitation reactions can lead to a development of potentially misleading microstructures. We propose a set of criteria that may help in distinguishing such microstructures from the ones that are created by crystal-plastic deformation.

  6. An Experimental Investigation of the Role of Radiation in Laboratory Bench-Top Experiments in Thermal Physics

    ERIC Educational Resources Information Center

    Twomey, Patrick; O'Sullivan, Colm; O'Riordan, John

    2009-01-01

    A simple undergraduate experiment designed to study cooling purely by radiation and cooling by a combination of convection and radiation is described. Results indicate that the contribution from radiative cooling in normal laboratory experiments is more significant than students often realize, even in the case of forced cooling. (Contains 1…

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

    ERIC Educational Resources Information Center

    Brunauer, Linda S.; Davis, Kathryn K.

    2008-01-01

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

  8. Resource Letter SPE-1: Single-Photon Experiments in the Undergraduate Laboratory

    NASA Astrophysics Data System (ADS)

    Galvez, Enrique J.

    2014-11-01

    This Resource Letter lists undergraduate-laboratory adaptations of landmark optical experiments on the fundamentals of quantum physics. Journal articles and websites give technical details of the adaptations, which offer students unique hands-on access to testing fundamental concepts and predictions of quantum mechanics. A selection of the original research articles that led to the implementations is included. These developments have motivated a rethinking of the way quantum mechanics is taught, so this Resource Letter also lists textbooks that provide these new approaches.

  9. Deformation measurement for a rotating deformable lap based on inverse fringe projection

    NASA Astrophysics Data System (ADS)

    Liao, Min; Zhang, Qican

    2015-03-01

    The active deformable lap (also namely stressed lap) is an efficient polishing tool in optical manufacturing. To measure the dynamic deformation caused by outside force on a deformable lap is important and helpful to the opticians to ensure the performance of a deformable lap as expected. In this paper, a manual deformable lap was designed to simulate the dynamic deformation of an active stressed lap, and a measurement system was developed based on inverse projected fringe technique to restore the 3D shape. A redesigned inverse fringe has been projected onto the surface of the measured lap, and the deformations of the tested lap become much obvious and can be easily and quickly evaluated by Fourier fringe analysis. Compared with the conventional projection, this technique is more obvious, and it should be a promising one in the deformation measurement of the active stressed lap in optical manufacturing.

  10. Constraints on behaviour of a mining‐induced earthquake inferred from laboratory rock mechanics experiments

    USGS Publications Warehouse

    McGarr, Arthur F.; Johnston, Malcolm J.; Boettcher, M.; Heesakkers, V.; Reches, Z.

    2013-01-01

    On December 12, 2004, an earthquake of magnitude 2.2, located in the TauTona Gold Mine at a depth of about 3.65 km in the ancient Pretorius fault zone, was recorded by the in-mine borehole seismic network, yielding an excellent set of ground motion data recorded at hypocentral distances of several km. From these data, the seismic moment tensor, indicating mostly normal faulting with a small implosive component, and the radiated energy were measured; the deviatoric component of the moment tensor was estimated to be M0 = 2.3×1012 N·m and the radiated energy ER = 5.4×108 J. This event caused extensive damage along tunnels within the Pretorius fault zone. What rendered this earthquake of particular interest was the underground investigation of the complex pattern of exposed rupture surfaces combined with laboratory testing of rock samples retrieved from the ancient fault zone (Heesakkers et al.2011a, 2011b). Event 12/12 2004 was the result of fault slip across at least four nonparallel fault surfaces; 25 mm of slip was measured at one location on the rupture segment that is most parallel with a fault plane inferred from the seismic moment tensor, suggesting that this segment accounted for much of the total seismic deformation. By applying a recently developed technique based on biaxial stick-slip friction experiments (McGarr2012, 2013) to the seismic results, together with the 25 mm slip observed underground, we estimated a maximum slip rate of at least 6.6 m/s, which is consistent with the observed damage to tunnels in the rupture zone. Similarly, the stress drop and apparent stress were found to be correspondingly high at 21.9 MPa and 6.6 MPa, respectively. The ambient state of stress, measured at the approximate depth of the earthquake but away from the influence of mining, in conjunction with laboratory measurements of the strength of the fault zone cataclasites, indicates that during rupture of the M 2.2 event, the normal stress acting on the large-slip fault

  11. Reconstitution of craniofacial osseous contour deformities, sequelae of trauma and post resection for tumors, with an alloplastic-autogenous graft.

    PubMed

    Leake, D L; Habal, M B

    1977-04-01

    Our experience using a new technique for reconstructing contour defects of facial bones has been presented. It employs particulate, cancellous bone and an implantable prosthesis accurately fabricated of polyether urethane and polyethylene terephthalate cloth mesh which can be produced in a variety of configurations. A mannequin made of these materials displaying the various parts of the craniofacial complex that have been restored or are currently under investigation is shown in Figure 10. Large cranial vault defects, orbital floors, mandibles including chin augmentation, and nasal bone deformities have been successfully restored in man. Restoration of the pinna of the ear is currently being evaluated in laboratory animals.

  12. A Survey on Faculty Perspectives on the Transition to a Biochemistry Course-Based Undergraduate Research Experience Laboratory

    ERIC Educational Resources Information Center

    Craig, Paul A.

    2017-01-01

    It will always remain a goal of an undergraduate biochemistry laboratory course to engage students hands-on in a wide range of biochemistry laboratory experiences. In 2006, our research group initiated a project for "in silico" prediction of enzyme function based only on the 3D coordinates of the more than 3800 proteins "of unknown…

  13. Accretion shocks in the laboratory: Design of an experiment to study star formation

    DOE PAGES

    Young, Rachel P.; Kuranz, C. C.; Drake, R. P.; ...

    2017-02-13

    Here, we present the design of a laboratory-astrophysics experiment to study magnetospheric accretion relevant to young, pre-main-sequence stars. Spectra of young stars show evidence of hotspots created when streams of accreting material impact the surface of the star and create shocks. The structures that form during this process are poorly understood, as the surfaces of young stars cannot be spatially resolved. Our experiment would create a scaled "accretion shock" at a major (several kJ) laser facility. The experiment drives a plasma jet (the "accretion stream") into a solid block (the "stellar surface"), in the presence of a parallel magnetic fieldmore » analogous to the star's local field.« less

  14. Ranking protective coatings: Laboratory vs. field experience

    NASA Astrophysics Data System (ADS)

    Conner, Jeffrey A.; Connor, William B.

    1994-12-01

    Environmentally protective coatings are used on a wide range of gas turbine components for survival in the harsh operating conditions of engines. A host of coatings are commercially available to protect hot-section components, ranging from simple aluminides to designer metallic overlays and ceramic thermal barrier coatings. A variety of coating-application processes are available, and they range from simple pack cementation processing to complex physical vapor deposition, which requires multimillion dollar facilities. Detailed databases are available for most coatings and coating/process combinations for a range of laboratory tests. Still, the analysis of components actually used in engines often yields surprises when compared against predicted coating behavior from laboratory testing. This paper highlights recent work to develop new laboratory tests that better simulate engine environments. Comparison of in-flight coating performance as well as industrial and factory engine testing on a range of hardware is presented along with laboratory predictions from standard testing and from recently developed cyclic burner-rig testing.

  15. Amniotic Constriction Bands: Secondary Deformities and Their Treatments.

    PubMed

    Drury, Benjamin T; Rayan, Ghazi M

    2018-01-01

    The purpose of this study was to report the surgical treatment experience of patients with amniotic constriction bands (ACB) over a 35-year interval and detail consequential limb deformities with emphasis on hands and upper extremities, along with the nature and frequency of their surgical treatment methods. Fifty-one patients were identified; 26 were males and 25 females. The total number of deformities was listed. The total number of operations, individual procedures, and operations plus procedures that were done for each patient and their frequency were recorded. The total number of operations was 117, and total number of procedures was 341. More procedures were performed on the upper extremity (85%) than the lower extremity (15%). Including the primary deformity ACB, 16 different hand deformities secondary to ACB were encountered. Sixteen different surgical methods for the upper extremity were utilized; a primary procedure for ACB and secondary reconstructions for all secondary deformities. Average age at the time of the first procedure was 9.3 months. The most common procedures performed, in order of frequency, were excision of ACB plus Z-plasty, release of partial syndactyly, release of fenestrated syndactyly, full-thickness skin grafts, resection of digital bony overgrowth from amputation stumps, and deepening of first and other digital web spaces. Many hand and upper extremity deformities secondary to ACB are encountered. Children with ACB may require more than one operation including multiple procedures. Numerous surgical methods of reconstruction for these children's secondary deformities are necessary in addition to the customary primary procedure of excision of ACB and Z-plasty.

  16. Hydrodynamic resistance and mobility of deformable objects in microfluidic channels

    PubMed Central

    Sajeesh, P.; Doble, M.; Sen, A. K.

    2014-01-01

    This work reports experimental and theoretical studies of hydrodynamic behaviour of deformable objects such as droplets and cells in a microchannel. Effects of mechanical properties including size and viscosity of these objects on their deformability, mobility, and induced hydrodynamic resistance are investigated. The experimental results revealed that the deformability of droplets, which is quantified in terms of deformability index (D.I.), depends on the droplet-to-channel size ratio ρ and droplet-to-medium viscosity ratio λ. Using a large set of experimental data, for the first time, we provide a mathematical formula that correlates induced hydrodynamic resistance of a single droplet ΔRd with the droplet size ρ and viscosity λ. A simple theoretical model is developed to obtain closed form expressions for droplet mobility ϕ and ΔRd. The predictions of the theoretical model successfully confront the experimental results in terms of the droplet mobility ϕ and induced hydrodynamic resistance ΔRd. Numerical simulations are carried out using volume-of-fluid model to predict droplet generation and deformation of droplets of different size ratio ρ and viscosity ratio λ, which compare well with that obtained from the experiments. In a novel effort, we performed experiments to measure the bulk induced hydrodynamic resistance ΔR of different biological cells (yeast, L6, and HEK 293). The results reveal that the bulk induced hydrodynamic resistance ΔR is related to the cell concentration and apparent viscosity of the cells. PMID:25538806

  17. Regional Educational Laboratory Researcher-Practitioner Partnerships: Documenting the Research Alliance Experience. REL 2018-291

    ERIC Educational Resources Information Center

    Scher, Lauren; McCowan, Ronald; Castaldo-Walsh, Cynthia

    2018-01-01

    This report provides a detailed account of the Regional Educational Laboratory (REL) Program's experience establishing and supporting research-practice partnerships (called "research alliances") during its 2012-17 contract cycle. The report adds to the growing literature base on researcher-practitioner partnerships by sharing how the…

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

    ERIC Educational Resources Information Center

    Yadav, Urvashi; Mande, Hemant; Ghalsasi, Prasanna

    2012-01-01

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

  19. Fault healing promotes high-frequency earthquakes in laboratory experiments and on natural faults

    USGS Publications Warehouse

    McLaskey, Gregory C.; Thomas, Amanda M.; Glaser, Steven D.; Nadeau, Robert M.

    2012-01-01

    Faults strengthen or heal with time in stationary contact and this healing may be an essential ingredient for the generation of earthquakes. In the laboratory, healing is thought to be the result of thermally activated mechanisms that weld together micrometre-sized asperity contacts on the fault surface, but the relationship between laboratory measures of fault healing and the seismically observable properties of earthquakes is at present not well defined. Here we report on laboratory experiments and seismological observations that show how the spectral properties of earthquakes vary as a function of fault healing time. In the laboratory, we find that increased healing causes a disproportionately large amount of high-frequency seismic radiation to be produced during fault rupture. We observe a similar connection between earthquake spectra and recurrence time for repeating earthquake sequences on natural faults. Healing rates depend on pressure, temperature and mineralogy, so the connection between seismicity and healing may help to explain recent observations of large megathrust earthquakes which indicate that energetic, high-frequency seismic radiation originates from locations that are distinct from the geodetically inferred locations of large-amplitude fault slip

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

    NASA Astrophysics Data System (ADS)

    Lefkos, Ioannis; Psillos, Dimitris; Hatzikraniotis, Euripides

    2011-07-01

    Background and purpose: The aim of this study was to explore the effect of investigative activities with manipulations in a virtual laboratory on students' ability to design experiments. Sample Fourteen students in a lower secondary school in Greece attended a teaching sequence on thermal phenomena based on the use of information and communication technology, and specifically of the simulated virtual laboratory 'ThermoLab'. Design and methods A pre-post comparison was applied. Students' design of experiments was rated in eight dimensions; namely, hypothesis forming and verification, selection of variables, initial conditions, device settings, materials and devices used, process and phenomena description. A three-level ranking scheme was employed for the evaluation of students' answers in each dimension. Results A Wilcoxon signed-rank test revealed a statistically significant difference between the students' pre- and post-test scores. Additional analysis by comparing the pre- and post-test scores using the Hake gain showed high gains in all but one dimension, which suggests that this improvement was almost inclusive. Conclusions We consider that our findings support the statement that there was an improvement in students' ability to design experiments.

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